WO2010119591A1 - Freezer-refrigerator and cooling storage unit - Google Patents

Abstract

A freezer-refrigerator comprising: a refrigeration compartment (2) for refrigerating and storing an object to be stored; a freezing compartment (4) for freezing and storing an object to be stored; a first compressor (11) for operating a first refrigeration cycle (10) in which a first refrigerant flows; a first heat dissipater (12) provided to a high-temperature section of the first refrigeration cycle (10); a first evaporator (14) provided to a low-temperature section of the first refrigeration cycle (10); a second compressor (21) for operating a second refrigeration cycle (20) in which a second refrigerant flows; a second evaporator (24) provided to a low-temperature section of the second refrigeration cycle (20); and an intermediate heat exchanger (31) for performing heat exchange between the low-temperature section of the first refrigeration cycle (10) and a high-temperature section of the second refrigeration cycle (20). The first evaporator (14) cools the refrigeration compartment (2), and the second evaporator (24) cools the freezing compartment (4).

Description

Refrigerator and refrigerator

The present invention relates to a refrigerator-freezer provided with first and second evaporators for cooling a refrigerator compartment and a freezer compartment, respectively. Moreover, it is related with the refrigerator provided with the 1st, 2nd cooling chamber from which temperature differs.

Conventional refrigerators are disclosed in Patent Documents 1 and 2. In the refrigerator-freezer disclosed in Patent Document 1, a refrigerant is circulated by a compressor and a refrigeration cycle is operated, and first and second evaporators are arranged in parallel in a low-temperature part of the refrigeration cycle. The first evaporator is disposed behind the freezer compartment. Cold air generated by exchanging heat with the first evaporator by driving the blower circulates in the freezer compartment and the refrigerator compartment, thereby cooling the refrigerator compartment and the refrigerator compartment. A 2nd evaporator is arrange | positioned in a freezer compartment and cools the store thing in a freezer compartment directly.

FIG. 600 shows a refrigeration cycle of a refrigerator-freezer disclosed in Patent Document 2. The refrigeration cycle 40 has a compressor 41, and the refrigerant circulates in the direction of the arrow by the compressor 41 to operate the refrigeration cycle 40. A radiator 42 is connected to the subsequent stage of the compressor 42, branched by a three-way valve 46, and first and second evaporators 44a and 44b are arranged in parallel via first and second decompression devices 43a and 43b. . Thereby, the radiator 42 is arrange | positioned at the high temperature part of the refrigerating cycle 40, and the 1st, 2nd evaporators 44a and 44b are arrange | positioned at a low temperature part.

The first and second evaporators 44a and 44b are disposed behind the refrigerator compartment and the freezer compartment, respectively. Blowers (not shown) are arranged in the vicinity of the first and second evaporators 44a and 44b, respectively. Cold air generated by exchanging heat with the first and second evaporators 44a and 44b by driving each blower circulates in the refrigerator compartment and the freezer compartment, respectively, and the refrigerator compartment and the freezer compartment are cooled.

On the other hand, Patent Documents 3 and 4 disclose a dual refrigeration cycle including first and second refrigeration cycles operated by first and second compressors, respectively. In the first and second refrigeration cycles, a refrigerant composed of carbon dioxide flows. An intermediate heat exchanger that performs heat exchange between the low temperature part of the first refrigeration cycle and the high temperature part of the second refrigeration cycle is provided, and an evaporator is disposed in the high temperature part of the second refrigeration cycle.

The operation of the first compressor maintains the intermediate heat exchanger in the low temperature part of the first refrigeration cycle at a low temperature. By the operation of the second compressor, the refrigerant in the second refrigeration cycle dissipates heat in the intermediate heat exchanger and is condensed. The evaporator in the low temperature part of the second refrigeration cycle is maintained at a lower temperature than the intermediate heat exchanger. Thereby, the cryogenic cold air heat-exchanged with the evaporator can be supplied to a storage chamber.

In addition, the second refrigeration cycle of the dual refrigeration cycle of Patent Document 4 is provided with a receiver after the intermediate heat exchanger. The receiver performs gas-liquid separation of the refrigerant flowing out from the intermediate heat exchanger of the second refrigeration cycle, and discharges the liquid refrigerant. Thereby, the bubble contained in the refrigerant | coolant which flows into an evaporator can be reduced, the circulation amount of a refrigerant | coolant can be ensured, and the fall of a cooling capability can be prevented.

Further, a conventional refrigerator-freezer is disclosed in Patent Document 5. This refrigerator / freezer has a freezer compartment at the top of the main body and a refrigerator compartment at the bottom. A machine room is provided behind the refrigerator compartment, and the first and second compressors are arranged in the machine room. The first compressor operates the first refrigeration cycle, and the refrigerator compartment is cooled by an evaporator disposed in a low temperature portion of the first refrigeration cycle. The second compressor operates the second refrigeration cycle, and the freezer compartment is cooled by an evaporator disposed in a low temperature part of the second refrigeration cycle. Thereby, a refrigerator compartment and a freezer compartment can be cooled independently, and power saving can be achieved.

In the refrigerator-freezer disclosed in Patent Document 2, a defrost heater is disposed below the first and second evaporators. The first and second evaporators are defrosted by stopping the compressor and driving each defrosting heater.

Further, Patent Document 6 discloses a refrigerator-freezer that performs defrosting of an evaporator by a refrigeration cycle. In this refrigerator-freezer, an evaporator is disposed at a low temperature portion of the refrigeration cycle, and a radiator is disposed at a high temperature portion. The radiator is installed on a metal back plate or the like of the refrigerator-freezer, and radiates heat to the outside air through the back plate by the operation of the refrigeration cycle. The evaporator is cooled by the operation of the refrigeration cycle, and the storage chamber is cooled by the cold air exchanged with the evaporator.

During defrosting of the evaporator, the refrigerant in the refrigeration cycle is circulated in the reverse direction by the switching means. Thereby, an evaporator is distribute | arranged to the high temperature part of a refrigerating cycle, and it heats up, and defrosting is performed.

In addition, the refrigerator-freezer disclosed in Patent Document 7 includes first and second evaporators connected in parallel to a compressor that operates a refrigeration cycle. The first and second evaporators are arranged in the low temperature part of the refrigeration cycle, and the refrigerant flow is switched by the switching means. In the first evaporator, a cooling plate is attached to a refrigerant pipe through which the refrigerant flows. The cooling plate is exposed covering a wide area on the back of the refrigerator compartment. A 2nd evaporator is distribute | arranged in the duct provided in the back of the freezer compartment, and many fins are attached to the refrigerant | coolant pipe | tube through which a refrigerant | coolant distribute | circulates. A blower is provided in the duct.

When the refrigerant flow path is switched to the first evaporator side, the temperature of the first evaporator is lowered, and the refrigerator compartment is cooled by the cold heat radiated from the cooling plate. When the flow path of the refrigerant is switched to the second evaporator side, the temperature of the second evaporator is lowered. The air flowing through the duct and the second evaporator are heat-exchanged by driving the blower to generate cold air, and the cold air is discharged into the freezer compartment to cool the freezer compartment.

Since the stored items in the refrigerator compartment are radiatively cooled by the cooling plate, the stored items can be prevented from drying without being directly exposed to cold air. Moreover, since cold heat is uniformly released from the cooling plate, the temperature distribution in the refrigerator compartment can be made uniform.

No.59-127878 (pages 3-8, Fig. 1) Japanese Patent Laid-Open No. 2002-122374 (2nd page to 7th page, FIG. 1) Japanese Patent Application Laid-Open No. 2004-279014 (pages 2-8, FIG. 1) Japanese Utility Model Publication No. 5-36258 (pages 5-6, FIG. 1) Japanese Patent Laid-Open No. 10-153375 (pages 3-5, FIG. 1) Japanese Patent Laid-Open No. 2002-340449 (pages 4-5, FIG. 1) Japanese Unexamined Patent Publication No. 2000-356445 (pages 3 to 6, FIG. 1)

The refrigerated room is kept at a higher room temperature than a freezer room in which stored items are refrigerated at, for example, 0 ° C. to 5 ° C. and stored at -20 ° C. for example. The refrigerators disclosed in Patent Documents 1 and 2 are maintained at the same temperature because the first and second evaporators are arranged in parallel. For this reason, the 1st evaporator which cools a refrigerator compartment is maintained at low temperature rather than the temperature of a freezer compartment.

The evaporator placed in the low temperature part of the refrigeration cycle can sufficiently cool the refrigerator at a temperature several degrees lower than the temperature of the refrigerator. On the other hand, it is known from the basic principle of thermodynamics that the cooling efficiency of the refrigeration cycle decreases as the temperature of the low temperature part decreases. For this reason, when the refrigerator compartment is cooled by the first evaporator having a temperature significantly lower than the indoor temperature of the refrigerator compartment, the COP (Coefficient Of Performance) of the refrigeration cycle is lowered. Therefore, there is a problem that the power consumption of the refrigerator / freezer increases.

In the dual refrigeration cycle disclosed in Patent Documents 3 and 4, an evaporator for generating cold air is provided in the second refrigeration cycle. For this reason, even if this dual refrigeration cycle is installed in a refrigerator-freezer, the refrigerator compartment and the freezer compartment are cooled by the same evaporator. Thereby, the temperature of an evaporator becomes remarkably low with respect to the room temperature of a refrigerator compartment similarly to the above, and there exists a problem which the power consumption of a refrigerator-freezer becomes large.

Further, according to the conventional refrigerator-freezer disclosed in Patent Document 5, the first and second compressors are arranged in the machine room provided in the lower part of the main body. Since the first and second compressors are point sound sources, the sound emitted from each is superimposed. In addition, when the first and second compressors are close to each other in the same machine room, sounds having the same phase and close frequency are likely to be generated. When the sound of the same phase is superimposed, the sound pressure level is doubled. In addition, a swell sound is likely to be generated by a sound having a close frequency. Therefore, there is a problem that the noise of the refrigerator / freezer increases.

Further, according to the refrigerator-freezer disclosed in the above-mentioned Patent Document 2, since the defrosting is performed by raising the temperature of the first and second evaporators by the defrost heater, there is a problem that the power consumption of the refrigerator-freezer increases. Moreover, according to the refrigerator-freezer disclosed by patent document 6, since a defrost heater is not provided, power consumption is reduced. However, there has been a problem in that the heat radiator disposed in the high temperature part of the refrigeration cycle is disposed in the low temperature part during defrosting, and condensation occurs on the heat radiator and the back plate.

Further, according to the refrigerator-freezer disclosed in Patent Document 7, since the refrigerant flows alternatively to the first and second evaporators, the refrigerator compartment and the freezer compartment cannot be cooled at the same time. For this reason, there has been a problem that sufficient cooling capacity cannot be obtained at the same time in the refrigerator compartment and the freezer compartment at the time of high load immediately after storing the stored items. In particular, the refrigerator compartment takes time to cool down due to radiation cooling, and the refrigerator compartment becomes insufficiently cooled when the refrigerator compartment is heavily loaded.

An object of the present invention is to provide a refrigerator-freezer that can reduce power consumption. Another object of the present invention is to provide a refrigerator-freezer and a refrigerator that can reduce noise. Another object of the present invention is to provide a refrigerator-freezer that can prevent condensation during defrosting and reduce power consumption. Another object of the present invention is to provide a refrigerator-freezer capable of improving the cooling capacity.

In order to achieve the above object, the refrigerator-freezer of the present invention includes a refrigerating room for storing stored items in a refrigerator, a freezing chamber for storing stored items in a frozen state, and a first compression that operates a first refrigeration cycle through which a first refrigerant flows. The first evaporator disposed in the low temperature part of the first refrigeration cycle, the second compressor operating the second refrigeration cycle through which the second refrigerant flows, and the low temperature part of the second refrigeration cycle. A second evaporator, and an intermediate heat exchanger that exchanges heat between the low temperature part of the first refrigeration cycle and the high temperature part of the second refrigeration cycle, and cooling the refrigerator compartment by the first evaporator; The freezing chamber is cooled by a second evaporator.

According to this configuration, the first and second refrigeration cycles are operated by the first and second compressors, and the first and second refrigerants are circulated to form the low temperature portion and the high temperature portion of the first and second refrigeration cycles, respectively. Is done. A first high-temperature and high-pressure refrigerant flows into the first radiator in the high-temperature part of the first refrigeration cycle to dissipate heat, and the first refrigerant is condensed. The first low-temperature and low-pressure refrigerant flows into the first evaporator and the intermediate heat exchanger in the low temperature part of the first refrigeration cycle, and the refrigerator compartment is cooled by the cold air cooled by the first evaporator. A high temperature and high pressure second refrigerant flows into the high temperature part of the second refrigeration cycle and is absorbed by the intermediate heat exchanger to dissipate heat. The low-temperature and low-pressure second refrigerant flows into the second evaporator in the low-temperature part of the second refrigeration cycle, and the freezer compartment is cooled by the cold air cooled by the second evaporator. The first evaporator and the intermediate heat exchanger may be arranged in series or in parallel.

Further, the present invention is characterized in that, in the refrigerator-freezer having the above-described configuration, the intermediate heat exchanger is arranged at the rear stage of the first evaporator. According to this structure, the 1st refrigerant | coolant after absorbing heat with a 1st evaporator flows in into an intermediate heat exchanger, and heat-exchanges with the high temperature part of a 2nd refrigerating cycle.

Further, the present invention is characterized in that in the refrigerator-freezer having the above-described configuration, a second radiator disposed in the high temperature part of the second refrigeration cycle is provided. According to this configuration, the high-temperature and high-pressure second refrigerant flows into the second radiator and the intermediate heat exchanger in the high-temperature part of the second refrigeration cycle, and the second refrigerant radiates heat by the second radiator and the intermediate heat exchanger. Condensed.

Further, the present invention is characterized in that, in the refrigerator-freezer having the above-described configuration, the intermediate heat exchanger is arranged at the subsequent stage of the second radiator. According to this structure, the 2nd refrigerant | coolant after thermally radiating with a 2nd heat sink flows into an intermediate heat exchanger, and heat-exchanges with the low temperature part of a 1st freezing cycle.

Further, the present invention is characterized in that, in the refrigerator-freezer configured as described above, heat exchange is performed between the second refrigerant flowing out from the second evaporator and the first refrigerant before flowing into the first evaporator. According to this structure, the low temperature 2nd refrigerant | coolant which flowed out from the 2nd evaporator absorbs heat from the 1st refrigerant | coolant before flowing into a 1st evaporator, the enthalpy of a 1st refrigerant | coolant falls, and a cooling capacity is higher as a refrigerant | coolant. The first refrigerant flows into the first evaporator.

Further, the present invention is characterized in that, in the refrigerator-freezer configured as described above, heat exchange is performed between the second refrigerant flowing out of the second evaporator and the second refrigerant before flowing into the second evaporator. According to this configuration, the low-temperature second refrigerant that has flowed out of the second evaporator absorbs heat from the second refrigerant before flowing into the second evaporator and the enthalpy of the second refrigerant is reduced, so that the refrigerant has a higher cooling capacity. The second refrigerant flows into the second evaporator.

According to the present invention, in the refrigerator-freezer configured as described above, a first internal heat exchanger that performs heat exchange between the high-temperature first refrigerant of the first refrigeration cycle and the low-temperature second refrigerant of the second refrigeration cycle, A second internal heat exchanger that exchanges heat between the high-temperature second refrigerant in the two refrigeration cycles and the low-temperature second refrigerant; and between the high-temperature first refrigerant and the low-temperature first refrigerant in the first refrigeration cycle And a third internal heat exchanger for exchanging heat.

According to this configuration, it becomes easy to match the evaporation temperature of the high-temperature cycle evaporator that cools the refrigerator compartment and the evaporation temperature of the low-temperature cycle evaporator that cools the refrigerator compartment to the set temperatures of the refrigerator compartment and the freezer compartment. . In addition, by providing an intermediate heat exchanger, the compression ratio of the high-temperature cycle compressor and the low-temperature cycle compressor can both be smaller than that of the conventional cycle, which increases the compression efficiency and saves energy. It can be set as an excellent refrigerator-freezer. Moreover, the arrangement of the third internal heat exchanger, the second internal heat exchanger, and the first internal heat exchanger can increase the refrigeration capacity of the refrigeration cycle, and the high-temperature cycle compressor and the low-temperature cycle compressor Since the temperature of the sucked refrigerant can be maintained at a temperature close to the ambient temperature, heat loss can be suppressed and a more rational refrigeration cycle can be achieved.

In the refrigerator refrigerator configured as described above, the third internal heat exchanger performs heat exchange between the first refrigerant flowing out from the first radiator and the first refrigerant flowing out from the intermediate heat exchanger. It is characterized by.

In the refrigerator having the above-described configuration, the present invention further includes a second radiator disposed in a high-temperature part of the second refrigeration cycle, in front of the intermediate heat exchanger, and the second internal heat exchanger is the intermediate heat exchanger. Heat exchange is performed between the second refrigerant flowing out of the second refrigerant and the second refrigerant flowing out of the second evaporator.

In the refrigerator refrigerator configured as described above, the first internal heat exchanger may exchange heat between the first refrigerant flowing out of the third internal heat exchanger and the second refrigerant flowing out of the second internal heat exchanger. It is characterized by performing.

According to the present invention, in the refrigerator-freezer having the above-described configuration, the first refrigerant is provided at a stage preceding the first evaporator to decompress the first refrigerant and includes a first decompression device including a capillary tube, and the first decompression device includes the first internal heat exchange. It functions as a heat exchange pipe of the heat exchanger or the third internal heat exchanger.

According to the present invention, in the refrigerator / freezer having the above-described configuration, the second refrigerant is provided at a stage preceding the second evaporator to depressurize the second refrigerant and includes a second decompression device including a capillary tube, and the second decompression device is configured to perform the second internal heat exchange. It is characterized by functioning as a heat exchange pipe for the vessel.

According to the present invention, in the refrigerator-freezer having the above-described configuration, a receiver that is disposed on the first refrigeration cycle side of the intermediate heat exchanger and separates the gas-liquid of the first refrigerant and discharges the gas refrigerant is provided. It is a feature.

According to this configuration, the first and second refrigeration cycles are operated by the first and second compressors, and the first and second refrigerants are circulated to form the low temperature portion and the high temperature portion of the first and second refrigeration cycles, respectively. Is done. The first low-temperature and low-pressure refrigerant flows into the first evaporator and the intermediate heat exchanger in the low temperature part of the first refrigeration cycle, and the refrigerator compartment is cooled by the cold air cooled by the first evaporator. A high temperature and high pressure second refrigerant flows into the high temperature part of the second refrigeration cycle and is absorbed by the intermediate heat exchanger to dissipate heat. The low-temperature and low-pressure second refrigerant flows into the second evaporator in the low-temperature part of the second refrigeration cycle, and the freezer compartment is cooled by the cold air cooled by the second evaporator. The first refrigerant flowing into the intermediate heat exchanger exchanges heat with the second refrigerant in a gas-liquid mixed state, and then the gas-state first refrigerant separated by the receiver exchanges heat with the second refrigerant and absorbs heat.

Further, according to the present invention, in the refrigerator with the above configuration, the intermediate heat exchanger exchanges heat between the upstream side of the first refrigeration cycle and the downstream side of the second refrigeration cycle, and the downstream side of the first refrigeration cycle and the second refrigeration cycle. It is characterized by heat exchange with the upstream side of the cycle. According to this configuration, the first refrigerant in the gas-liquid mixed state flowing into the intermediate heat exchanger exchanges heat with the second refrigerant radiated by the intermediate heat exchanger. The gas-state first refrigerant that has passed through the receiver exchanges heat with the high-temperature second refrigerant that has flowed into the intermediate heat exchanger.

Further, the present invention provides the refrigerator with the above configuration, wherein the intermediate heat exchanger mainly takes latent heat from the second refrigerant upstream of the receiver of the first refrigeration cycle to give latent heat to the first refrigerant. And a sensible heat exchange section that mainly takes sensible heat from the second refrigerant downstream of the receiver of the first refrigeration cycle and applies sensible heat to the first refrigerant. According to this configuration, the first refrigerant in the gas-liquid mixed state flowing into the intermediate heat exchanger takes the condensation heat (latent heat) of the second refrigerant and vaporizes it. The first refrigerant in the gas state that has passed through the receiver takes up the sensible heat of the high-temperature second refrigerant and rises in temperature.

The present invention further includes a first refrigerator and a second radiator disposed in the high-temperature portions of the first and second refrigeration cycles in the refrigerator-freezer having the above-described configuration, and the intermediate heat exchanger is provided at the subsequent stage of the second radiator. It is characterized by the arrangement. According to this configuration, the first refrigerant radiates heat in the first radiator by driving the first compressor, and then flows through the first evaporator and the intermediate heat exchanger in the low temperature part. When the second compressor is driven, the second refrigerant radiates heat at the second radiator and drops in temperature, and then flows into the intermediate heat exchanger to exchange heat with the first refrigerant.

In the refrigerator having the above-described configuration, the second refrigerant that has flowed out of the second evaporator performs heat exchange with the second refrigerant that has flowed out of the intermediate heat exchanger. It is characterized in that heat exchange is performed with the first refrigerant that has flowed out. According to this configuration, the second refrigerant flowing out from the intermediate heat exchanger is absorbed by the low-temperature second refrigerant flowing out from the second evaporator, and the enthalpy is reduced. Further, the first refrigerant flowing out from the first radiator is absorbed by the low-temperature second refrigerant flowing out from the second evaporator, and the enthalpy is lowered. Thereby, the 1st, 2nd refrigerant | coolant with high cooling capacity flows in into a 1st, 2nd evaporator.

Further, the present invention is characterized in that, in the refrigerator-freezer having the above-described configuration, the first and second refrigerants are made of isobutane.

Further, the present invention is characterized in that the boiling point of the first refrigerant is higher than the boiling point of the second refrigerant in the refrigerator-freezer configured as described above.

Further, the present invention is characterized in that, in the refrigerator-freezer configured as described above, the first refrigerant is made of isobutane and the second refrigerant is made of propane or carbon dioxide.

In order to achieve the above object, the refrigerator-freezer of the present invention includes a main body having a refrigeration chamber for storing stored items in a refrigerated state and a heat insulating box having a freezing chamber for storing stored items in a frozen state, and a first refrigerant flowing through the first refrigerant. A first compressor that operates one refrigeration cycle, a first evaporator that is disposed in a low temperature portion of the first refrigeration cycle and cools the refrigerator compartment, and a second that operates a second refrigeration cycle through which a second refrigerant flows. A compressor, a second evaporator disposed in a low temperature part of the second refrigeration cycle for cooling the freezing chamber, a first machine chamber in which the first compressor is disposed, and a second compressor in which the second compressor is disposed. And two machine chambers, one of the first and second machine chambers being disposed above the main body portion and the other being disposed below the main body portion.

According to this configuration, the first and second refrigeration cycles are operated by the first and second compressors, and the first and second refrigerants are circulated to form the low temperature portion and the high temperature portion of the first and second refrigeration cycles, respectively. Is done. The refrigerator compartment is cooled by the first evaporator in the low temperature part of the first refrigeration cycle, and the freezer room is cooled by the second evaporator in the low temperature part of the second refrigeration cycle. The first and second compressors are respectively disposed in first and second machine chambers provided in the main body. For example, the first machine room is provided in the upper part of the main body part, and the second machine room is provided in the lower part of the main body part. Thereby, the first and second compressors are arranged apart from each other.

Moreover, this invention is a refrigerator-freezer of the said structure, Heat exchange between the 1st heat exchange part distribute | arranged to the back | latter stage of a 1st evaporator, and the 2nd heat exchange part distribute | arranged to the high temperature part of a 2nd refrigerating cycle It is characterized by having an intermediate heat exchanger. According to this configuration, the low-temperature and low-pressure first refrigerant flows into the first heat exchange part of the low-temperature part of the first refrigeration cycle, and the high-temperature and high-pressure second refrigerant flows into the second heat exchange part of the high-temperature part of the second refrigeration cycle. The refrigerant flows in. Thereby, the heat of the second refrigerant is absorbed by the first refrigerant in the intermediate heat exchanger.

Further, the present invention provides a refrigerator-freezer having the above-described configuration, wherein the refrigeration chamber and the freezer compartment are arranged side by side vertically, and the first and second machine chambers are disposed in the vicinity of the refrigerator compartment and the freezer compartment, respectively. A first evaporator and a second evaporator are disposed behind the refrigerator compartment and the freezer compartment, respectively, and the intermediate heat exchanger is arranged between the first compressor and the second compressor and extends vertically. In addition, the first heat exchange part and the second heat exchange part bend in the vertical direction, and the refrigerant inlet and the refrigerant outlet of the first and second heat exchange parts are provided in the vicinity of the first machine chamber. It is a feature.

According to this configuration, for example, the refrigerating chamber is disposed above the main body portion, the first machine chamber having the first compressor is disposed at the upper portion of the main body portion, and the freezing chamber is disposed below the main body portion to perform the second compression. A second machine room having a machine is arranged at the lower part of the main body. The first evaporator is disposed on the upper portion of the main body, and the second evaporator is disposed on the lower portion of the main body. The intermediate heat exchanger is provided so as to extend up and down the main body, and is formed by bending in the vertical direction. A refrigerant inlet and a refrigerant outlet are formed at the upper ends of the first and second heat exchange units. The first heat exchange unit has a refrigerant inlet connected to the first evaporator and a refrigerant outlet connected to the first compressor. The second heat exchange unit has a refrigerant inlet disposed on the second compressor side and a refrigerant outlet disposed on the second evaporator side.

Further, the present invention provides a refrigerator with the above configuration, wherein the first radiator disposed in the high temperature portion of the first refrigeration cycle, the first decompressor disposed downstream of the first radiator, and the second refrigeration cycle A second decompression device disposed downstream of the intermediate heat exchanger, and a first internal heat exchanger extending vertically to exchange heat between the second refrigerant flowing out of the second evaporator and the first decompression device And a second internal heat exchanger extending vertically to exchange heat between the second refrigerant flowing out of the second evaporator and the second decompression device, and the refrigerant inflow side of the first decompression device is the second While being provided in the vicinity of the compressor, the refrigerant inflow side of the second decompression device is provided in the vicinity of the first compressor.

According to this configuration, the high-temperature and high-pressure first refrigerant flows into the first radiator to dissipate heat, and the first refrigerant is condensed. The first refrigerant condensed by the first radiator flows into the first decompressor, and the first refrigerant is decompressed and expanded to become low-temperature wet steam having a low dryness. The second refrigerant condensed in the intermediate heat exchanger flows into the second decompression device, and the second refrigerant is decompressed and expanded to become low-temperature wet steam having a low dryness.

The second refrigerant that has flowed out of the second evaporator absorbs heat by exchanging heat with the first decompression device in the first internal heat exchanger. Thereby, the enthalpy of a 1st refrigerant | coolant falls and the 1st refrigerant | coolant with higher cooling capability flows into a 1st evaporator. The second refrigerant that has flowed out of the second evaporator absorbs heat by exchanging heat with the second decompression device in the second internal heat exchanger. Thereby, the enthalpy of the second refrigerant is lowered, and the second refrigerant having a higher cooling capacity flows into the second evaporator.

For example, when the first machine room is disposed at the top, the second internal heat exchanger is provided extending vertically, and the refrigerant inflow side of the second decompression device is disposed at the top of the main body. The refrigerant outflow side of the second decompression device is connected to a second evaporator disposed in the lower part. The first internal heat exchanger is provided extending continuously up and down from the upper end of the second internal heat exchanger. The refrigerant inflow side of the first decompression device is arranged in the lower part of the main body, and the refrigerant outflow side of the first decompression device is connected to a first evaporator arranged in the upper part.

According to the present invention, in the refrigerator with the above-described configuration, the first dryer for dehumidifying the first refrigerant before flowing into the first pressure reducing device is disposed in the second machine chamber, and the second refrigerant before flowing into the second pressure reducing device. A second dryer for removing moisture is disposed in the first machine room.

According to this configuration, the first refrigerant from which moisture has been removed by the first dryer flows into the first decompressor, and the second refrigerant from which moisture has been removed by the second dryer flows into the second decompressor. For example, when the first machine room is arranged at the upper part, the first dryer is arranged at the lower part of the main body part and connected to the refrigerant inflow side of the first decompression device, and the second dryer is arranged at the upper part of the main body part. Connected to the refrigerant inflow side of the decompression device.

Further, the present invention is characterized in that the second dryer is covered with a heat insulating material in the refrigerator-freezer configured as described above.

Further, the present invention is the refrigerator-freezer having the above-described configuration, wherein the intermediate heat exchanger includes a double tube that covers an inner tube with an outer tube, and a first refrigerant flows through the inner tube to form a first heat exchange unit. The second refrigerant flows through the outer pipe in the opposite direction to the first refrigerant to form a second heat exchange part. According to this configuration, the first refrigerant flowing through the inner pipe and the second refrigerant flowing through the outer pipe exchange heat through the inner pipe.

Further, the present invention is characterized in that the second heat radiator is provided between the second compressor and the intermediate heat exchanger in the refrigerator-freezer configured as described above. According to this configuration, the high-temperature and high-pressure second refrigerant flows into the second radiator and dissipates heat, and the second refrigerant is cooled down. The second refrigerant lowered in temperature by the second radiator is further cooled and condensed by the intermediate heat exchanger.

Moreover, in this invention, the 1st, 2nd internal heat exchanger was embedded in the back wall of the said heat insulation box, and the 2nd heat radiator was arrange | positioned in the back surface of the said main-body part in the refrigerator refrigerator of the said structure. It is a feature.

Further, the present invention is characterized in that, in the refrigerator-freezer configured as described above, the intermediate heat exchanger is embedded in the back wall of the heat insulating box.

Further, the present invention is characterized in that the accumulator for separating the gas and liquid is installed on the refrigerant outflow side of the second evaporator and not installed on the refrigerant outflow side of the first evaporator in the refrigerator-freezer having the above configuration. According to this configuration, the second refrigerant flowing out from the second evaporator is gas-liquid separated by the accumulator, and the gas refrigerant is sent to the second compressor. The gas-liquid mixed first refrigerant flowing out from the first evaporator flows into the intermediate heat exchanger, and the first refrigerant becomes a gas refrigerant by heat exchange with the high temperature part of the second refrigeration cycle and is sent to the first compressor. It is done.

Further, the present invention is characterized in that, in the refrigerator-freezer configured as described above, a heat insulating wall that partitions the refrigerator compartment and the freezing chamber has a heat insulating performance equivalent to that of the peripheral wall of the heat insulating box.

Further, the present invention is characterized in that, in the refrigerator-freezer configured as described above, a part of the heat radiation of the first radiator is utilized for drain water treatment and prevention of dew condensation of the refrigerator-freezer.

The present invention also provides a refrigerator compartment for storing stored items in a refrigerator, a freezing chamber for storing stored items in a frozen state, a first compressor for operating a first refrigeration cycle through which a first refrigerant flows, and a low temperature of the first refrigeration cycle. A first evaporator that cools the refrigerator compartment, a second compressor that operates a second refrigeration cycle through which a second refrigerant flows, and a freezer compartment that is disposed in a low temperature section of the second refrigeration cycle. And a second evaporator for cooling the second evaporator. The second evaporator is defrosted by heat of a high temperature part of the first refrigeration cycle.

According to this configuration, the first and second refrigeration cycles are operated by the first and second compressors, and the first and second refrigerants are circulated to form the low temperature portion and the high temperature portion of the first and second refrigeration cycles, respectively. Is done. The low temperature and low pressure first refrigerant flows into the first evaporator in the low temperature part of the first refrigeration cycle, and the refrigerator compartment is cooled by the cold air cooled by the first evaporator. The low-temperature and low-pressure second refrigerant flows into the second evaporator in the low-temperature part of the second refrigeration cycle, and the freezer compartment is cooled by the cold air cooled by the second evaporator.

During the defrosting of the second evaporator, the operation of the second refrigeration cycle is stopped and the first refrigeration cycle is operated. The high temperature part of the first refrigeration cycle and the second evaporator exchange heat, the second evaporator is heated and defrosting is performed.

Moreover, in the refrigerator with the above-described configuration, the present invention branches between the first radiator disposed in the high temperature portion of the first refrigeration cycle, the three-way valve provided on the refrigerant inflow side of the first radiator, and the three-way valve. A defrosting heat exchanger that is arranged in parallel with the first radiator and exchanges heat with the second evaporator, and a check valve provided on the refrigerant outflow side of the defrosting heat exchanger, The three-way valve is switched to the defrosting heat exchanger when defrosting the second evaporator.

According to this configuration, the flow path of the first refrigerant is switched to the first radiator side by the three-way valve when the refrigerator compartment and the freezer compartment are cooled. As a result, the first and second evaporators are cooled and radiated from the first radiator. At this time, the check valve prevents the first refrigerant from flowing into the defrosting heat exchanger from the refrigerant outflow side of the first radiator. During the defrosting of the second evaporator, the flow path of the first refrigerant is switched to the defrosting heat exchanger side by the three-way valve. Thereby, the first evaporator is cooled and radiated from the defrosting heat exchanger. The second evaporator is heated with heat exchange with the defrosting heat exchanger, and defrosting is performed.

Moreover, the present invention is characterized in that, in the refrigerator-freezer having the above-described configuration, the check valve is disposed in the vicinity of a junction point between the refrigerant outlet side of the first radiator and the refrigerant outlet side of the defrosting heat exchanger. . According to this configuration, the check valve and the defrosting heat exchanger are arranged apart from each other. For this reason, when the flow path of the first refrigerant is switched to the first radiator side by the three-way valve, the temperature rise of the second evaporator due to the high-temperature first refrigerant flowing out from the first radiator is reduced.

Moreover, this invention is a refrigerator-freezer of the said structure, A 2nd evaporator and the said heat exchanger for defrost have the 1st, 2nd refrigerant | coolant pipe | tube through which a 1st, 2nd refrigerant | coolant distribute | circulates, respectively, Two refrigerant tubes are connected by a plurality of fins. According to this structure, the heat | fever of a high temperature 1st refrigerant | coolant is transmitted to a 2nd evaporator via the fin which connects a 1st, 2nd refrigerant pipe.

Moreover, this invention is a refrigerator-freezer of the said structure, A 2nd evaporator and the said heat exchanger for defrost have the 1st, 2nd refrigerant | coolant pipe | tube through which a 1st, 2nd refrigerant | coolant distribute | circulates, respectively, Two refrigerant pipes are adjacent to each other. According to this structure, the heat | fever of a high temperature 1st refrigerant | coolant is transmitted to a 2nd evaporator via the boundary wall of a 1st, 2nd refrigerant pipe.

Further, the present invention is characterized in that, in the refrigerator-freezer configured as described above, the cross-sectional area of the refrigerant tube of the defrosting heat exchanger is set to be ½ or less of the cross-sectional area of the refrigerant tube of the first evaporator. According to this configuration, the internal volume of the refrigerant pipe of the defrosting heat exchanger is reduced, and a large amount of refrigerant is prevented from accumulating in the defrosting heat exchanger after defrosting.

Further, the present invention is characterized in that, in the refrigerator-freezer configured as described above, the first compressor is stopped for a predetermined period before defrosting the second evaporator. According to this configuration, when the first compressor is stopped and the three-way valve is switched to the defrosting heat exchanger side, the room temperature of the refrigerator compartment rises, and the first compressor is driven when a predetermined period elapses. Thus, the first refrigerant flows through the defrosting heat exchanger, the second evaporator is defrosted, and the refrigerator compartment is cooled. The three-way valve may be switched to the defrosting heat exchanger side after the predetermined period has elapsed.

The present invention also provides a refrigerator compartment for storing stored items in a refrigerator, a freezing chamber for storing stored items in a frozen state, a first compressor for operating a first refrigeration cycle through which a first refrigerant flows, and a low temperature of the first refrigeration cycle. A first evaporator that cools the refrigerator compartment, a second compressor that operates a second refrigeration cycle through which a second refrigerant flows, and a freezer compartment that is disposed in a low temperature section of the second refrigeration cycle. A second evaporator that cools the refrigerator, and the first evaporator is formed by fixing a metal cooling plate that covers the wall surface of the refrigerator compartment to a refrigerant pipe, and the refrigerator plate is radiatively cooled by the cooling plate. It is a feature.

According to this configuration, the first and second refrigeration cycles are operated by the first and second compressors, and the first and second refrigerants are circulated to form the low temperature portion and the high temperature portion of the first and second refrigeration cycles, respectively. Is done. The low-temperature and low-pressure first refrigerant flows into the refrigerant pipe of the first evaporator in the low-temperature part of the first refrigeration cycle, and cold heat is radiated from the cooling plate to cool the refrigerator compartment. The low-temperature and low-pressure second refrigerant flows into the second evaporator in the low-temperature part of the second refrigeration cycle, and the freezer compartment is cooled by the cold air cooled by the second evaporator.

Further, the present invention provides a refrigerator-freezer having the above-described configuration, a door opening / closing detection unit that detects opening / closing of the door of the refrigerator compartment, a temperature sensor that detects the temperature of the refrigerator compartment, and a humidity sensor that detects the humidity of the refrigerator compartment. And when the door is opened and closed, a dew point temperature of the refrigerating room is acquired by detection of the temperature sensor and the humidity sensor, and a first refrigeration cycle is performed so that the first evaporator is below the dew point temperature. It is characterized by driving.

According to this configuration, when the door opening / closing detection unit detects that the door is opened and closed, the temperature sensor and the humidity sensor detect the temperature and humidity of the refrigerator compartment. The dew point temperature of the refrigerator compartment is acquired by calculation or the like from the detection results of the temperature sensor and the humidity sensor, and the first evaporator is maintained below the dew point temperature. Thereby, the moisture of the outside air that flows in by opening and closing the door is condensed on the surface of the cooling plate.

Further, the present invention is characterized in that in the refrigerator-freezer having the above-described configuration, an intermediate heat exchanger that performs heat exchange between the low temperature part of the first refrigeration cycle and the high temperature part of the second refrigeration cycle is provided. According to this configuration, the low-temperature and low-pressure first refrigerant flows into the first evaporator and the intermediate heat exchanger in the low-temperature part of the first refrigeration cycle. A high temperature and high pressure second refrigerant flows into the high temperature part of the second refrigeration cycle and is absorbed by the intermediate heat exchanger to dissipate heat. The first evaporator and the intermediate heat exchanger may be arranged in series or in parallel.

Further, the present invention is characterized in that, in the refrigerator-freezer configured as described above, an isolation chamber having a temperature lower than that of the upper part is provided in the lower part of the refrigeration chamber, and the refrigerant flows through the refrigerant pipe of the first evaporator from below to above. . According to this configuration, a low temperature isolation room such as a chilled room or an ice greenhouse is provided in the lower part of the refrigerating room. A cooling plate below the first evaporator is in contact with the low-temperature refrigerant pipe to cool the isolation chamber.

Moreover, the refrigerator of the present invention includes first and second cooling chambers, a first compressor that operates a first refrigeration cycle through which a first refrigerant flows, and a first heat radiation that is disposed in a high temperature portion of the first refrigeration cycle. A first evaporator disposed in a low temperature part of the first refrigeration cycle, a second compressor operating a second refrigeration cycle through which the second refrigerant flows, and a low temperature part of the second refrigeration cycle. A second evaporator and an intermediate heat exchanger for exchanging heat between the low temperature part of the first refrigeration cycle and the high temperature part of the second refrigeration cycle, and cooling the first cooling chamber by the first evaporator The second cooling chamber is cooled by the second evaporator.

Moreover, the refrigerator of this invention is a refrigerator of the said structure, The 1st internal heat exchanger which performs heat exchange between the high temperature 1st refrigerant | coolant of a 1st refrigeration cycle, and the low temperature 1st refrigerant | coolant of a 2nd refrigeration cycle. A second internal heat exchanger that exchanges heat between the high-temperature second refrigerant and the low-temperature second refrigerant in the second refrigeration cycle, and the high-temperature first refrigerant and the low-temperature first refrigerant in the first refrigeration cycle And a third internal heat exchanger for exchanging heat with each other.

The refrigerator of the present invention further includes a receiver that is disposed on the first refrigeration cycle side of the intermediate heat exchanger and separates the gas-liquid of the first refrigerant and discharges the gas refrigerant in the refrigerator having the above configuration. It is characterized by that.

The refrigerator of the present invention is arranged in a main body having first and second cooling chambers, a first compressor that operates a first refrigeration cycle through which a first refrigerant flows, and a low-temperature part of the first refrigeration cycle. The first evaporator that cools the first cooling chamber, the second compressor that operates the second refrigeration cycle through which the second refrigerant flows, and the second cooling chamber that is disposed in the low temperature part of the second refrigeration cycle A second evaporator, a first machine room in which the first compressor is arranged, and a second machine room in which the second compressor is arranged, wherein one of the first and second machine rooms is the main body portion. The other is arranged at the lower part of the main body part.

Moreover, the refrigerator of the present invention is arranged in the first and second cooling chambers, the first compressor that operates the first refrigeration cycle in which the first refrigerant flows, and the low temperature portion of the first refrigeration cycle, so that the first cooling is performed. A first evaporator that cools the chamber, a second compressor that operates a second refrigeration cycle through which the second refrigerant flows, and a second evaporator that is disposed in a low temperature portion of the second refrigeration cycle and cools the first cooling chamber. And the second evaporator is defrosted by the heat of the high temperature part of the first refrigeration cycle.

According to the present invention, there is provided an intermediate heat exchanger for exchanging heat between the low temperature part of the first refrigeration cycle operated by the first compressor and the high temperature part of the second refrigeration cycle operated by the second compressor. In the two-stage refrigeration cycle type refrigerator-freezer, the refrigerator compartment is cooled by the first evaporator provided in the first refrigeration cycle, and the freezer compartment is cooled by the second evaporator provided in the second refrigeration cycle. For this reason, the temperature difference between the first evaporator and the refrigerator compartment can be reduced, and the first and second compressors can be operated with high efficiency. Therefore, the COP of the refrigeration cycle can be improved, and the power consumption of the refrigeration refrigerator can be reduced.

Further, according to the present invention, since the receiver is provided on the first refrigeration cycle side of the intermediate heat exchanger, the first refrigerant of the gas refrigerant exchanges heat with the second refrigerant even if the heat load of the refrigeration refrigerator fluctuates. Thereby, the temperature of the first refrigerant is surely raised and sent to the first compressor, and the capability of the intermediate heat exchanger can be maintained. In addition, since the first refrigerant of the gas refrigerant flowing out from the receiver absorbs heat and is heated up, it flows into the first compressor, so that it is possible to reduce the heat loss.

Further, according to the present invention, one of the first and second machine chambers in which the first and second compressors are arranged is arranged at the upper part of the main body and the other is arranged at the lower part. A second compressor is located remotely. Since the sound pressure level of the point sound source decreases as the distance increases, the level of noise felt by the user decreases because the sound source is away from the other sound source when approaching one sound source. In addition, since the first and second compressors are arranged in different rooms, it is difficult for sounds having the same phase and the same frequency to be generated. Thereby, while the sound pressure which superimposed the sound of the 1st, 2nd compressor falls, generation | occurrence | production of a wave | undulation can be reduced. Therefore, the noise of the refrigerator / freezer can be reduced.

According to the present invention, the second evaporator of the second refrigeration cycle is defrosted by the heat of the high temperature portion of the first refrigeration cycle, so the first radiator of the first refrigeration cycle and the second radiator of the second refrigeration cycle. Does not cool. Therefore, dew condensation on the back plate of the refrigerator can be prevented. Further, it is not necessary to separately provide a heater for defrosting the second evaporator, and the temperature rise by the heater or the like during defrosting can be suppressed. Further, most of the heat for heating the second evaporator during defrosting is the heat from the refrigerator compartment, and the refrigerator compartment can be cooled while defrosting. Therefore, power consumption due to defrosting can be suppressed and power consumption of the refrigerator-freezer can be kept low.

According to the present invention, the first and second compressors operate the first and second refrigeration cycles, respectively, and the first and second evaporators cool the refrigerator and the freezer compartment, and the first evaporator is a cooling plate. Therefore, it is possible to obtain sufficient cooling capacity of the refrigerator and the freezer compartment at the time of high load immediately after storing the stored material while preventing the stored material from drying. In particular, the temperature of the second evaporator can be lowered when the refrigerator compartment is heavily loaded, and insufficient cooling of the freezer compartment can be prevented. In addition, the temperature of the first evaporator can be lowered when the freezer compartment is under a high load, and condensation in the cooling plate can be maintained to maintain the humidity in the refrigerator compartment. Thereby, even when a freezer compartment becomes high load, drying of the stored matter of a refrigerator compartment can be reduced.

Side surface sectional view which shows the refrigerator-freezer of 1st Embodiment of this invention. The figure which shows the refrigerating cycle of the freezer refrigerator of 1st Embodiment of this invention. PH diagram of the refrigerator-freezer according to the first embodiment of the present invention. Diagram showing the relationship between adiabatic compression efficiency and compression ratio of positive displacement compressors The figure which shows the refrigerating cycle of the freezer refrigerator of 2nd Embodiment of this invention. The figure which shows the refrigerating cycle of the freezer refrigerator of 3rd Embodiment of this invention. The figure which shows the detail of the intermediate heat exchanger of the refrigerating cycle of the refrigerator-freezer of 3rd Embodiment of this invention. PH diagram of the refrigerator-freezer according to the third embodiment of the present invention. The figure which shows the relationship between the position and temperature of the intermediate heat exchanger of the refrigerating cycle of the refrigerator-freezer of 3rd Embodiment of this invention. The figure which shows the refrigerating cycle of a comparative example The figure which shows the relationship between the position and temperature of the intermediate heat exchanger of the refrigerating cycle of a comparative example The figure which shows the refrigerating cycle of the refrigerator-freezer of 4th Embodiment of this invention. PH diagram of the refrigerator-freezer according to the fourth embodiment of the present invention. The figure which shows the other structure of the 1st, 3rd internal heat exchanger of the refrigerating cycle of the refrigerator-freezer of 4th Embodiment of this invention. Side surface sectional drawing which shows the refrigerator-freezer of 5th Embodiment of this invention. The rear perspective view which shows piping of the refrigerator-freezer of 5th Embodiment of this invention. The figure which shows the refrigerating cycle of the refrigerator-freezer of 5th Embodiment of this invention. The figure which shows the refrigerating cycle of the refrigerator-freezer of 6th Embodiment of this invention. Detailed view showing a heat exchanger for defrosting and a second evaporator of a refrigerator-freezer according to a sixth embodiment of the present invention. The flowchart which shows the operation | movement at the time of defrosting of the 2nd evaporator of the freezer refrigerator of 6th Embodiment of this invention. Front view showing a refrigerator-freezer according to a seventh embodiment of the present invention. Front sectional drawing which shows piping of the refrigerator-freezer of 7th Embodiment of this invention. The block diagram which shows the structure of the refrigerator-freezer of 7th Embodiment of this invention. Front sectional view showing piping of a refrigerator-freezer according to an eighth embodiment of the present invention. The figure which shows the freezing cycle of the conventional freezer refrigerator

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing the refrigerator-freezer of the first embodiment. The refrigerator-freezer 1 is provided with a refrigerator compartment 2 for storing stored items in a refrigerator. Below the refrigerator compartment 2 is provided a vegetable compartment 3 which is maintained at a temperature higher than that of the refrigerator compartment 2 and suitable for storage of vegetables. A freezer compartment 4 for storing stored items in a frozen state is disposed at the bottom of the freezer 1. The front surface of the refrigerator compartment 2 is opened and closed by a rotating heat insulating door 2a. The front surfaces of the vegetable compartment 3 and the freezer compartment 4 are opened and closed by drawer-type heat insulating doors 3a and 4a integrated with the storage cases 3b and 4b, respectively.

A machine room 5 is provided behind the freezer room 4. First and second compressors 11 and 21 for operating first and second refrigeration cycles 10 and 20 (see FIG. 2), which will be described in detail later, are disposed in the machine room 5. A first evaporator 14 connected to the first compressor 11 is disposed on the back surface of the refrigerator compartment 2, and a refrigerator refrigerator 15 is disposed above the first evaporator 14. A second evaporator 24 connected to the second compressor 21 is disposed on the back surface of the freezer compartment 4, and a freezer compartment blower 25 is disposed above the second evaporator 24. A defrost heater 51 is provided below the first evaporator 14.

The cold air cooled by exchanging heat with the first evaporator 14 is discharged to the refrigerator compartment 2 by the refrigerator compartment fan 15. The cold air flows through the refrigerator compartment 2 and flows into the vegetable compartment 3 communicating with the refrigerator compartment 2. The cold air that has flowed into the vegetable compartment 3 flows through the vegetable compartment 3 and returns to the first evaporator 14. Thereby, the refrigerator compartment 2 and the vegetable compartment 3 are cooled. The cold air cooled by exchanging heat with the second evaporator 24 is discharged to the freezer compartment 4 by the freezer blower 25. The cold air discharged into the freezer compartment 4 flows through the freezer compartment 4 and returns to the second evaporator 24. Thereby, the freezer compartment 4 is cooled.

FIG. 2 shows the refrigeration cycle of the refrigerator 1. The refrigeration cycle 30 of the refrigerator 1 is a cascade type dual refrigeration cycle in which the first and second refrigeration cycles 10 and 20 are connected by an intermediate heat exchanger 31. That is, the first refrigeration cycle 10 forms a high temperature cycle, and the second refrigeration cycle 20 forms a low temperature cycle. Then, heat exchange is performed between the low temperature part of the first refrigeration cycle 10 and the high temperature part of the second refrigeration cycle 20 by the intermediate heat exchanger 31. Accordingly, the low temperature part of the second refrigeration cycle 20 is maintained at a lower temperature than the low temperature part of the first refrigeration cycle 10.

The first refrigeration cycle 10 operated by the first compressor 11 has a first radiator 12, a first decompressor 13, and a first evaporator 14 connected by a refrigerant pipe 10a. A first refrigerant such as isobutane flows in the direction of arrow S1 in the refrigerant pipe 10a. That is, the first refrigerant circulates through the first compressor 11, the first radiator 12, the first decompressor 13, the first evaporator 14, and the first compressor 11 in this order.

The second refrigeration cycle 20 operated by the second compressor 21 has a second radiator 22, a second decompression device 23, and a second evaporator 24 connected by a refrigerant pipe 20a. A second refrigerant such as isobutane flows in the direction of the arrow S2 in the refrigerant pipe 20a. That is, the second refrigerant circulates through the second compressor 21, the second radiator 22, the second decompressor 23, the second evaporator 24, and the second compressor 21 in this order.

The intermediate heat exchanger 31 is formed such that the heat exchanging portion 31a provided in the first refrigeration cycle 10 and the heat exchanging portion 31c provided in the second refrigeration cycle 20 are adjacent to each other and can exchange heat with each other through wall surfaces. The heat exchanging part 31 a is arranged downstream of the first evaporator 14, and the heat exchanging part 31 c is arranged downstream of the second radiator 22.

First and second internal heat exchangers 32 and 33 are provided in the first and second refrigeration cycles 10 and 20, respectively. The first internal heat exchanger 32 is formed so that the heat exchanging part 32a provided in the first refrigeration cycle 10 and the heat exchanging part 32b provided in the second refrigeration cycle 20 are adjacent to each other and can exchange heat via wall surfaces. .

The heat exchanging part 32a is arranged at the rear stage of the first radiator 12, and the high-temperature first refrigerant before flowing into the first evaporator 14 flows therethrough. The heat exchanging part 32b is arranged downstream of the second evaporator 24, and the low-temperature second refrigerant after flowing out of the second evaporator 24 flows therethrough. In the case where the first pressure reducing device 13 is formed of a capillary tube, the heat exchanging portion 32 a may also serve as the first pressure reducing device 13.

The second internal heat exchanger 33 is adjacent to the heat exchanging part 33a disposed downstream of the heat exchanging part 31c and the heat exchanging part 33b disposed downstream of the second evaporator 24, and exchanges heat with each other via the wall surface. Formed possible. The high-temperature second refrigerant before flowing into the second evaporator 24 flows through the heat exchange unit 33a, and the low-temperature second refrigerant after flowing out of the second evaporator 24 flows through the heat exchange unit 33b. In the case where the second decompression device 23 is made of a capillary tube, the heat exchanging portion 33a may also serve as the second decompression device 23.

In the refrigerator-freezer 1 configured as described above, the first and second refrigerants flow through the refrigerant pipes 10a and 26 by driving the first and second compressors 11 and 21, respectively. The first and second compressors 11 and 21 compress the first and second refrigerants to high temperature and high pressure, and the first and second decompression devices 13 and 23 decompress and expand the first and second refrigerants at low temperature and low pressure. To.

Accordingly, the first and second refrigeration cycles 10 and 20 until the first and second refrigerants flow out of the first and second compressors 11 and 21 and flow into the first and second decompression devices 13 and 23. It becomes the high temperature part. The low temperature of the first and second refrigeration cycles 10 and 20 until the first and second refrigerant flows out of the first and second decompression devices 13 and 23 and flows into the first and second compressors 11 and 21. Part.

The first high-temperature and high-pressure refrigerant compressed by the first compressor 11 is deprived of heat by the first radiator 12 and condensed. The first refrigerant liquefied by the first radiator 12 is deprived of heat by the first refrigerant in the low temperature part of the second refrigeration cycle 20 by the first internal heat exchanger 32 and further cooled. The liquid first refrigerant cooled by the first internal heat exchanger 32 and having a high degree of supercooling flows into the first pressure reducing device 13. The first refrigerant is decompressed and expanded by the first decompression device 13, and becomes a low-temperature wet steam having a low dryness.

The first refrigerant that has become low-temperature wet steam flows into the first evaporator 14, takes heat away from the cold air in the refrigerator compartment 2, and evaporates to become wet steam with higher dryness. The first refrigerant in the wet vapor state flowing out from the first evaporator 14 flows into the intermediate heat exchanger 31 and evaporates while taking heat from the second refrigerant in the high temperature part of the second refrigeration cycle to become superheated vapor. The first refrigerant that has become superheated steam returns to the first compressor 11. As a result, the first refrigerant circulates and the first refrigeration cycle 10 is operated.

The high-temperature and high-pressure second refrigerant compressed by the second compressor 21 is deprived of ambient air by the second radiator 22. The second refrigerant lowered in temperature by the second radiator 22 flows into the intermediate heat exchanger 31 and is deprived of heat by the first refrigerant in the low temperature part of the first refrigeration cycle 10 to be condensed. The liquefied second refrigerant is deprived of heat by the second internal heat exchanger 33 in the low temperature portion of the second refrigeration cycle 20 and further cooled.

The second refrigerant in the liquid state cooled by the second internal heat exchanger 33 and having a high degree of supercooling flows into the second decompression device 23. The second refrigerant is decompressed and expanded by the second decompression device 23, and becomes low-temperature wet steam. The second refrigerant that has become low-temperature wet steam flows into the second evaporator 24, takes heat from the cold air in the freezer compartment 4 and evaporates to become wet steam.

The second refrigerant in the wet vapor state flowing out from the second evaporator 24 is guided to the second internal heat exchanger 33 and the first internal heat exchanger 32, and takes heat from the high-temperature second refrigerant and the first refrigerant and overheats. It becomes steam. The second refrigerant that has become superheated steam returns to the second compressor 21. As a result, the second refrigerant circulates and the second refrigeration cycle 20 is operated.

The second compressor 21 is driven after the temperature of the intermediate heat exchanger 31 is lowered after the first compressor 11 is driven. And the temperature of the refrigerator compartment 2 and the freezer compartment 4, and the temperature difference of the heat exchange parts 31a and 31c of the intermediate | middle heat exchanger 31 are monitored, and the 1st, 2nd compressor is controlled by inverter control so that these may become predetermined value. The rotational speeds 11 and 21 are controlled.

FIG. 3 shows a pressure-enthalpy diagram (PH diagram) of the refrigeration cycle 30. The vertical axis represents pressure, and the horizontal axis represents enthalpy. Further, in the figure, each point A, B, C, D, E, E ′, a, b, b ′, c, d, e, and f corresponds to each point of the refrigeration cycle shown in FIG. .

In the case of the first refrigeration cycle 10 (ABBCDE-E'-A), AB represents the process in the first compressor 11. BC represents the process in the first radiator 12. CD represents the process in the heat exchange section 32a of the first internal heat exchanger 32. DE represents the process in the first pressure reducing device 13. E-E ′ represents a process in the first evaporator 14. E′-A represents a process in the heat exchange section 31 a of the intermediate heat exchanger 31.

The same applies to the second refrigeration cycle 20 (ab-b'-cd-fa), where ab represents the process in the second compressor 21. b-b ′ represents a process in the second radiator 22. b′-c represents a process in the heat exchanging section 31 c of the intermediate heat exchanger 31. cd represents the process in the heat exchange section 33a of the second internal heat exchanger 33. “de” represents a process in the second decompression device 23. ef represents the process in the second evaporator 24. “fa” represents a process in the heat exchange section 33b of the second internal heat exchanger 33 and the heat exchange section 32b of the first internal heat exchanger 32.

Since the same refrigerant (for example, isobutane) is sealed in the first and second refrigeration cycles 10 and 20, the temperature relationship and pressure relationship of the first and second refrigeration cycles 10 and 20 are found on the PH diagram. It has become easier. For example, the pressure PA at the point A of the first refrigeration cycle 10 is slightly lower than the pressure Pb at the point b of the second refrigeration cycle 20. This is because the first refrigeration cycle 10 takes heat from the second refrigeration cycle 20.

In the case of the conventional single refrigeration cycle 40 (see FIG. 600), if the freezer compartment 4 has the same set temperature, the evaporation temperatures of the first and second evaporators 44a and 44b (see FIG. 600) are as shown in FIG. The degree is represented by ef. In contrast, the evaporation temperature of the first evaporator 14 for cooling the refrigerator compartment 2 of the present embodiment is represented by EF in FIG. In the area of the wet steam of the refrigerant, the higher the pressure P, the higher the temperature, so that the evaporation temperature of the first evaporator 14 becomes higher than in the single refrigeration cycle.

Thereby, in the case of the conventional single refrigeration cycle 40, for example, the temperature difference between the first evaporator 14 and the refrigerator compartment 2 which has been 20 ° C. can be remarkably reduced to, for example, 5 ° C. or less. Therefore, the highly efficient refrigerator-freezer 1 can be provided without using wasteful energy for cooling the refrigerator compartment 2.

Further, in the case of the conventional single refrigeration cycle 40, if the temperature setting conditions are the same, the condensation pressure becomes the pressure PB at the point B, and the evaporation pressure becomes the pressure Pa at the point a. For this reason, the compression ratio of the compressor 41 (see FIG. 600) is PB / Pa. On the other hand, in the present embodiment, the compression ratio of the first refrigeration cycle 10 is PB / PA, and the compression ratio of the second refrigeration cycle 20 is Pb / Pa. For this reason, both become smaller than the compression ratio of the refrigeration cycle 40.

Figure 4 shows the relationship between the adiabatic compression efficiency and compression ratio of a positive displacement compressor according to "Guide and Data Book" (1961, p498) of ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers-American Heating, Refrigerating and Air Conditioning Society). Show. The vertical axis represents adiabatic compression efficiency, and the horizontal axis represents the compression ratio. Note that most of the compressors currently used in ordinary refrigerator-freezers are of the positive displacement type. Although the refrigerant is experimental data of R12 and R22, it can be said that other refrigerants have the same tendency. According to the figure, the smaller the compression ratio of the compressor, the higher the adiabatic compression efficiency of the compressor.

In the case where the ambient temperature is 25 ° C., the temperature in the refrigerator compartment 2 is 3 ° C., the temperature in the freezer compartment 4 is −18 ° C., and the first and second refrigerants are usually used in isobutane, the conventional single refrigeration cycle 40 The compression ratio (see FIG. 600) is about 8. In contrast, the compression ratios of the first and second refrigeration cycles 10 and 20 are about 2 to 3, respectively. Therefore, since the compression ratios of the first and second refrigeration cycles 10 and 20 are both smaller than the conventional one, the first and second compressors 11 and 21 can be operated with high efficiency.

According to the present embodiment, the heat exchange is performed between the low temperature part of the first refrigeration cycle 10 operated by the first compressor 11 and the high temperature part of the second refrigeration cycle 20 operated by the second compressor 21. In the refrigerator-freezer 1 of the two-stage refrigeration cycle type provided with the heat exchanger 31, the second evaporation provided in the second refrigeration cycle 20 by cooling the refrigerator compartment 2 by the first evaporator 14 provided in the first refrigeration cycle 10. The freezer compartment 4 is cooled by the vessel 24. For this reason, the temperature difference between the first evaporator 14 and the refrigerator compartment 2 can be reduced, and the first and second compressors 11 and 21 can be operated with high efficiency. Therefore, the COP of the refrigeration cycle 30 is improved as compared with the conventional case, and the power consumption of the refrigerator-freezer 1 can be reduced.

The intermediate heat exchanger 31 may be disposed in parallel with the first evaporator 14. However, when the intermediate heat exchanger 31 is arranged in series behind the first evaporator 14, the first refrigerant flows through the first evaporator 14 before the intermediate heat exchanger 31 takes away the heat of the second refrigerant. Therefore, the first evaporator 14 takes heat from the air in the refrigerating chamber 2 without lowering the temperature of the air in the refrigerating chamber 2 by heat exchange due to latent heat, so that the cooling efficiency can be improved.

Moreover, since the second radiator 22 arranged in the high temperature part of the second refrigeration cycle 20 is provided, the heat radiation temperature of the first and second refrigeration cycles 10 and 20 as a whole can be further lowered. Therefore, the COP of the refrigeration cycle 30 is improved.

At this time, the intermediate heat exchanger 31 may be arranged in parallel with the second radiator 22. However, since the intermediate heat exchanger 31 is arranged at the subsequent stage of the second radiator 22, the second refrigerant flows through the second radiator 22 before the heat is taken away by the first refrigerant by the intermediate heat exchanger 31. Thereby, since the 2nd refrigerant | coolant after heat-exchanging with the 2nd heat radiator 22 and thermally radiating is cooled by the intermediate heat exchanger 31, heat exchange can be performed more efficiently.

In addition, since the first internal heat exchanger 32 that performs heat exchange between the second refrigerant flowing out of the second evaporator 24 and the first refrigerant before flowing into the first evaporator 14 is provided, the first refrigerant Enthalpy can be reduced, and the cooling capacity of the first refrigerant flowing into the first evaporator 14 can be further improved.

In addition, since the second internal heat exchanger 33 that performs heat exchange between the second refrigerant flowing out from the second evaporator 24 and the second refrigerant before flowing into the second evaporator 24 is provided, the second refrigerant Enthalpy can be reduced, and the cooling capacity of the second refrigerant flowing into the second evaporator 24 can be further improved.

Further, by the cold energy recovery in the first and second internal heat exchangers 32 and 33, the second refrigerant flowing out of the second evaporator 24 is heated to about the ambient temperature in the endothermic process fa of FIG. For this reason, a heat loss can be suppressed, without the suction piping of the 2nd compressor 21 installed in a machine room taking heat from ambient air. Further, the temperature of the second refrigerant compressed by the second compressor 21 becomes higher than the ambient temperature, and heat can be radiated from the second radiator 22 to the surroundings in the heat radiation process bb ′ of FIG.

In addition, the refrigeration cycle 30 has a low overall heat radiation temperature level, and the discharge temperature Tb of the second compressor 21 is even lower than the discharge temperature TB of the first compressor 11. For this reason, the temperature of the refrigerant sucked into the second compressor 21 cannot be sufficiently increased only by the second internal heat exchanger 33. By providing the first internal heat exchanger 32 in addition to the second internal heat exchanger 33, the temperature of the second refrigerant sucked into the second compressor 21 is increased to such an extent that the temperature after compression exceeds the ambient temperature. Can do. Accordingly, heat can be radiated from the second radiator 22 to the surroundings in the heat radiation process bb ′ of FIG.

Next, FIG. 5 is a diagram showing a refrigeration cycle of the refrigerator-freezer 1 of the second embodiment. For convenience of explanation, the same parts as those in the first embodiment shown in FIGS. 1 to 4 are given the same reference numerals. The refrigeration cycle 30 of the refrigerator-freezer 1 of the present embodiment has the second radiator 22, the first and second internal heat exchangers 32 and 33 (both see FIG. 2) omitted from the first embodiment. Other parts are the same as those in the first embodiment.

According to the present embodiment, since the second radiator 22 and the first and second internal heat exchangers 32 and 33 (see FIG. 2) are omitted from the first embodiment, the second internal heat exchangers 32 and 33 are omitted. The COP of the refrigeration cycle 30 is slightly reduced. However, the cost can be reduced by simplifying the configuration of the refrigeration cycle 30 compared to the first embodiment.

Similarly to the first embodiment, heat is generated between the low temperature part of the first refrigeration cycle 10 operated by the first compressor 11 and the high temperature part of the second refrigeration cycle 20 operated by the second compressor 21. In the refrigerator-freezer 1 of the two-stage refrigeration cycle type provided with the intermediate heat exchanger 31 for exchanging, the refrigerator compartment 2 is cooled by the first evaporator 14 provided in the first refrigeration cycle 10 and provided in the second refrigeration cycle 20. The freezing chamber 4 is cooled by the second evaporator 24. For this reason, the temperature difference between the first evaporator 14 and the refrigerator compartment 2 can be reduced, and the first and second compressors 11 and 21 can be operated with high efficiency. Therefore, the COP of the refrigeration cycle 30 is improved as compared with the conventional case, and the power consumption of the refrigerator-freezer 1 can be reduced.

Next, FIG. 6 shows a refrigeration cycle of the refrigerator-freezer 1 of the third embodiment. For convenience of explanation, the same parts as those in the first embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals. In the present embodiment, the first receiver 17 is provided on the first refrigeration cycle 10 side of the intermediate heat exchanger 31, and the second receiver 27 is provided downstream of the second evaporator 24. Other parts are the same as those in the first embodiment.

The first and second receivers 17 and 27 separate the gas and liquid, store the liquid refrigerant, and discharge the gas refrigerant. The first receiver 17 prevents the liquid refrigerant from flowing into the first compressor 11, and the second receiver 27 prevents the liquid refrigerant from flowing into the second compressor 21.

FIG. 7 is a diagram showing details of the intermediate heat exchanger 31. The intermediate heat exchanger 31 is formed such that the heat exchanging parts 31a and 31b provided in the first refrigeration cycle 10 and the heat exchanging parts 31c and 31d provided in the second refrigeration cycle 20 are adjacent to each other and can exchange heat via wall surfaces. Is done. The heat exchanging part 31 a is arranged downstream of the first evaporator 14, and the heat exchanging part 31 d is arranged downstream of the second radiator 22.

Heat exchange units 31a and 31b are provided on the upstream side and downstream side of the first receiver 17 on the first refrigeration cycle 10 side of the intermediate heat exchanger 31, respectively. As a result, the heat exchange unit 31a is vaporized by the vaporization (latent heat) of the first refrigerant mixed with the gas and liquid, and the heat exchange unit 31b is heated by the sensible heat of the first refrigerant in the gas state.

The heat exchange unit 31a on the upstream side of the first refrigeration cycle 1 performs heat exchange adjacent to the heat exchange unit 31c on the downstream side of the second refrigeration cycle 20. Further, the heat exchanging portion 31 b on the downstream side of the first refrigeration cycle 1 performs heat exchange adjacent to the heat exchanging portion 31 d on the upstream side of the second refrigeration cycle 20. At this time, the heat exchange unit 31d mainly releases sensible heat from the high-temperature second refrigerant, and the second refrigerant cooled by the heat exchange unit 31d mainly releases the condensation heat (latent heat) at the heat exchange unit 31c. The length of the heat exchange parts 31c and 31d is set. Therefore, the heat exchange units 31a and 31c constitute a latent heat exchange unit that gives the latent heat of the second refrigerant as the latent heat of the first refrigerant, and the heat exchange units 31b and 31d convert the sensible heat of the second refrigerant to the sensible heat of the first refrigerant. The sensible heat exchange section given as

In the refrigerator-freezer 1 configured as described above, the first refrigerant in the wet vapor state that has flowed out of the first evaporator 14 flows into the heat exchange section 31 a of the intermediate heat exchanger 31. The first refrigerant evaporates while taking away the latent heat of the second refrigerant in the heat exchanging part 31 c in the heat exchanging part 31 a and flows into the first receiver 17.

The first refrigerant that has flowed into the first receiver 17 is gas-liquid separated, the liquid refrigerant is stored, and the gas refrigerant is discharged. The first refrigerant in a gas state discharged from the first receiver 17 is heated to become superheated steam while taking mainly sensible heat of the heat exchange part 31d in the heat exchange part 31b.

The second refrigerant lowered in temperature by the second radiator 22 flows into the heat exchange part 31d of the intermediate heat exchanger 31. The second refrigerant that has flowed into the heat exchanging portion 31d is further cooled by mainly taking sensible heat from the first refrigerant in the heat exchanging portion 31b. The temperature-reduced second refrigerant in the gas state flows into the heat exchanging part 31c, and is mainly deprived of latent heat and condensed by the first refrigerant in the heat exchanging part 31a. The condensed second refrigerant is further lowered in temperature by the second internal heat exchanger 33 where heat is taken away by the second refrigerant in the low temperature portion of the second refrigeration cycle 20.

FIG. 8 shows a pressure-enthalpy diagram (PH diagram) of the refrigeration cycle 30 of the present embodiment. The vertical axis represents pressure, and the horizontal axis represents enthalpy. Further, in the figure, each point A, B, C, D, E, E ′, F, a, b, b ′, b ″ c, d, e, and f are the points of the refrigeration cycle shown in FIG. Correspondingly, point F and point b ″ are added to FIG. 3 described above.

That is, E′-F represents a process in the heat exchange part 31 a of the intermediate heat exchanger 31. FA represents a process in the heat exchanging portion 31b of the intermediate heat exchanger 31. Further, b′-b ″ represents a process in the heat exchange part 31d of the intermediate heat exchanger 31. b ″ -c represents a process in the heat exchange part 31c of the intermediate heat exchanger 31.

FIG. 9 is a diagram showing the relationship between the position of the intermediate heat exchanger 31 and the temperature. For comparison, FIG. 11 shows the relationship between the position of the intermediate heat exchanger 31 and the temperature of the refrigeration cycle 30 ′ shown in FIG. 10. In the refrigeration cycle 30 ′ of the comparative example, the first receiver 17 is arranged at the rear stage of the intermediate heat exchanger 31. Other portions are the same as those of the refrigeration cycle 30 shown in FIG. 600 described above. 9 and 11, the vertical axis indicates the temperature, and the horizontal axis indicates the position of the intermediate heat exchanger 31. In the drawing, each point A, F, E ', b', b ", c corresponds to each point of the refrigeration cycle 30, 30 'shown in Figs.

On the second refrigeration cycle 20 side of the intermediate heat exchanger 31 of the comparative example, the second refrigerant dissipates heat in the heat exchange part 31d (b'-b ") and is condensed in the heat exchange part 31c (b" -c). On the first refrigeration cycle 10 side of the intermediate heat exchanger 31, the first refrigerant evaporates at the heat exchange unit 31a (E'-F) and also evaporates at the heat exchange unit 31b (FA).

For this reason, the temperature difference between the first and second refrigerants in the heat exchanging portion 31b becomes large, and the loss due to heat exchange is large. Further, since the first refrigerant of the gas refrigerant flowing out from the first receiver 17 does not absorb heat from the second refrigeration cycle 20, it flows into the first compressor 1 at the evaporation temperature. Therefore, the heat loss is likely to occur.

In contrast, on the first refrigeration cycle 10 side of the intermediate heat exchanger 31 of the present embodiment, the first refrigerant evaporates in the heat exchange unit 31a (E′-F), and in the heat exchange unit 31b (FA). It absorbs heat. For this reason, in the intermediate heat exchanger 31, latent heat exchange and sensible heat exchange are performed in matching. Therefore, the temperature difference required for heat exchange can be minimized, and loss of effective energy due to heat exchange can be reduced. Further, since the first refrigerant absorbs heat and is heated to flow into the first compressor 11, the heat loss can be reduced.

According to this embodiment, as in the first embodiment, the low temperature part of the first refrigeration cycle 10 operated by the first compressor 11 and the high temperature part of the second refrigeration cycle 20 operated by the second compressor 21 In the two-stage refrigeration cycle type refrigerator-freezer 1 provided with the intermediate heat exchanger 31 that performs heat exchange between the refrigerator compartment 2 is cooled by the first evaporator 14 provided in the first refrigeration cycle 10 and second refrigeration is performed. The freezer compartment 4 is cooled by the second evaporator 24 provided in the cycle 20. For this reason, the temperature difference between the first evaporator 14 and the refrigerator compartment 2 can be reduced, and the first and second compressors 11 and 21 can be operated with high efficiency. Therefore, the COP of the refrigeration cycle 30 is improved as compared with the conventional case, and the power consumption of the refrigerator-freezer 1 can be reduced.

Further, since the first receiver 17 is provided on the first refrigeration cycle 10 side of the intermediate heat exchanger 31, the first refrigerant of the gas refrigerant exchanges heat with the second refrigerant even if the heat load of the refrigerator / freezer 1 fluctuates. Thereby, the temperature of the first refrigerant is reliably raised and sent to the first compressor 11, and the capability of the intermediate heat exchanger 31 can be maintained. In addition, since the first refrigerant of the gas refrigerant that has flowed out of the first receiver 17 absorbs heat and then rises in temperature, it flows into the first compressor 11, so that the heat loss can be reduced.

In addition, the intermediate heat exchanger 31 exchanges heat between the heat exchanging portion 31 a on the upstream side of the first refrigeration cycle 10 and the heat exchanging portion 31 c on the downstream side of the second refrigeration cycle 20. Since the heat exchanging part 31b and the heat exchanging part 31d on the upstream side of the second refrigeration cycle 20 exchange heat, the first refrigerant in the gas state flowing out of the first receiver 17 exchanges heat with the high-temperature second refrigerant. Thereby, the sensible heat by the heat radiation of the second refrigerant is used for the sensible heat for raising the temperature of the first refrigerant, and the temperature difference in heat exchange between the first and second refrigerants can be reduced. Therefore, the loss of effective energy due to heat exchange can be reduced, and the power consumption of the refrigerator-freezer 1 can be further reduced.

In addition, the first refrigerant mainly takes latent heat from the second refrigerant in the latent heat exchanger (31a, 31c), and the first refrigerant mainly receives sensible heat from the second refrigerant in the sensible heat exchanger (31b, 31d). Therefore, the latent heat exchange and the sensible heat exchange of the first and second refrigerants are performed in matching, and the temperature difference between the two can be further reduced.

Next, FIG. 12 shows the refrigeration cycle of the refrigerator-freezer 1 of the fourth embodiment. For convenience of explanation, the same reference numerals are given to the same parts as those of the third embodiment shown in FIG. In the present embodiment, a third internal heat exchanger 34 is provided at the subsequent stage of the first radiator 12. Other parts are the same as those of the third embodiment.

The third internal heat exchanger 34 adjoins the heat exchange part 34a arranged at the rear stage of the first radiator 12 and the heat exchange part 34b arranged at the rear stage of the intermediate heat exchanger 31, and heats them through the wall surfaces. Formed interchangeably. The high temperature first refrigerant that has flowed out of the first radiator 12 circulates in the heat exchange part 34a, and the low temperature first refrigerant that has flowed out of the intermediate heat exchanger 31 circulates in the heat exchange part 34b.

The first refrigerant liquefied by the first radiator 12 flows into the heat exchange part 34a of the third internal heat exchanger 34. Further, the first refrigerant that has flowed out of the heat exchanging portion 31 b of the intermediate heat exchanger 31 flows into the heat exchanging portion 34 b of the third internal heat exchanger 34. The first refrigerant (high temperature refrigerant) in the heat exchange unit 34a is deprived of heat by the first refrigerant (low temperature refrigerant) flowing into the heat exchange unit 34b.

And the 1st refrigerant | coolant which flowed out from the heat exchange part 34a of the 3rd internal heat exchanger 34 flows in into the heat exchange part 32a of the 1st internal heat exchanger 32. FIG. In addition, the first refrigerant that has flowed out of the heat exchange part 34 b of the third internal heat exchanger 34 returns to the first compressor 11.

FIG. 13 shows a pressure-enthalpy diagram (PH diagram) of the refrigeration cycle 30 of this embodiment. The vertical axis represents pressure, and the horizontal axis represents enthalpy. Also, in the figure, points A, B, C, C ′, D, E, E ′, F, F ′, a, b, b ′, b ″ c, d, e, and f are shown in FIG. Corresponding to each point of the refrigeration cycle, points C ′, F ′, and f ′ are added to FIG. 8 described above.

That is, C-C ′ represents a process in the heat exchange part 34 a of the third internal heat exchanger 34. C′-D represents a process in the heat exchange section 32 a of the first internal heat exchanger 32. F-F ′ represents a process in the heat exchange part 31 b of the intermediate heat exchanger 31. F′-A represents a process in the heat exchange section 34 b of the third internal exchanger 34. Further, f−f ′ represents a process in the heat exchange part 33 b of the second internal heat exchanger 33. f′-a represents a process in the heat exchange part 32 b of the first internal heat exchanger 32.

The second refrigeration cycle 20 that generates less heat of evaporation than the first refrigeration cycle 10 has a smaller refrigerant flow rate than the first refrigeration cycle 10. However, when the first refrigerant in the first refrigeration cycle 10 takes heat from the second refrigerant in the second refrigeration cycle 20 in the intermediate heat exchanger 31, the temperature of the first refrigerant is often lower by 10 ° C. or more than the ambient temperature. Become. For this reason, when the 3rd internal heat exchanger 34 does not exist, the suction piping of the 1st compressor 11 installed in a machine room becomes lower than ambient temperature, and heat loss arises.

In contrast, when the third internal heat exchanger 34 is provided, the first refrigerant flowing out from the intermediate heat exchanger 31 is surrounded by the cold recovery of the third internal heat exchanger 34 in the endothermic process F′-A of FIG. Heated to about temperature. For this reason, the heat loss by the suction piping of the 1st compressor 11 can be suppressed.

FIG. 14 shows an example in which the first internal heat exchanger 32 and the third internal heat exchanger 34 are configured using the fact that the first decompression device 13 is a capillary tube. That is, the first pressure reducing device 13 is caused to function as a heat exchange pipe for the first internal heat exchanger 32 or the third internal heat exchanger 34. In the figure, the first pressure reducing device 13 constitutes the heat exchange part 32a of the first internal heat exchanger 32 and the heat exchange part 34a of the third internal heat exchanger 34, but may be either one.

1st decompression device 13 forms heat exchange part 34a of the 3rd internal heat exchanger 34, joins piping by soldering etc., and adheres to heat exchange part 34b. The first pressure reducing device 13 forms a heat exchange part 32a of the first internal heat exchanger 32, and joins the pipes to each other by soldering or the like so as to be in close contact with the heat exchange part 32b.

The high-temperature and high-pressure first refrigerant that has flowed into the first decompression device 13 is deprived of heat by the low-temperature and low-pressure first refrigerant that first flows out from the intermediate heat exchanger 31 in the third internal heat exchanger 34. Subsequently, the first refrigerant is deprived of heat by the low-temperature and low-pressure second refrigerant flowing out from the second internal heat exchanger 33 in the first internal heat exchanger 32. Therefore, the first refrigerant expands while being deprived of heat by the third internal heat exchanger 34 and the first internal heat exchanger 32, and becomes a low-temperature and low-pressure refrigerant.

As a result, the first decompression device 13 made of a capillary tube functions as a heat exchange pipe of the first internal heat exchanger 32 or the third internal heat exchanger 34, thereby reducing the number of parts and the manufacturing cost of the refrigerator-freezer 1 Can be lowered.

Similarly, by utilizing the fact that the second decompression device 23 is a capillary tube, the second decompression device 23 can function as the heat exchange part 33a of the second internal heat exchanger 33. At this time, the second pressure reducing device 23 is brought into close contact with the heat exchanging portion 33b inside the second internal heat exchanger 33 and joined by soldering or the like.

The high-temperature and high-pressure second refrigerant that has flowed into the second decompression device 23 is deprived of heat by the low-temperature and low-pressure second refrigerant that has flowed out of the second receiver 27 in the second internal heat exchanger 33. The second refrigerant expands while being deprived of heat by the second internal heat exchanger 33, and becomes a low-temperature and low-pressure refrigerant. Thereby, like the above, the number of parts can be reduced and the manufacturing cost of the refrigerator-freezer 1 can be reduced.

The first and second decompression devices 13 and 23 of the first and third embodiments described above may be formed by capillary tubes, and the first and second internal heat exchangers 32 and 33 may be configured similarly.

According to this embodiment, as in the first embodiment, the low temperature part of the first refrigeration cycle 10 operated by the first compressor 11 and the high temperature part of the second refrigeration cycle 20 operated by the second compressor 21 In the two-stage refrigeration cycle type refrigerator-freezer 1 provided with the intermediate heat exchanger 31 that performs heat exchange between the refrigerator compartment 2 is cooled by the first evaporator 14 provided in the first refrigeration cycle 10 and second refrigeration is performed. The freezer compartment 4 is cooled by the second evaporator 24 provided in the cycle 20. For this reason, the temperature difference between the first evaporator 14 and the refrigerator compartment 2 can be reduced, and the first and second compressors 11 and 21 can be operated with high efficiency. Therefore, the COP of the refrigeration cycle 30 is improved as compared with the conventional case, and the power consumption of the refrigerator-freezer 1 can be reduced.

In addition, since the third internal heat exchanger 34 that performs heat exchange between the high-temperature first refrigerant and the low-temperature first refrigerant in the first refrigeration cycle 10 is provided, by the cold recovery of the third internal heat exchanger 34 The low temperature first refrigerant is heated to about ambient temperature. For this reason, the heat loss by the suction piping of the 1st compressor 11 can be suppressed.

Further, since the third internal heat exchanger 34 exchanges heat between the first refrigerant flowing out of the first heat radiator 12 and the first refrigerant flowing out of the intermediate heat exchanger 31, it is easy to cool the first refrigerant. Can be recovered.

Further, since the second internal heat exchanger 33 exchanges heat between the second refrigerant flowing out from the intermediate heat exchanger 31 and the second refrigerant flowing out from the second evaporator 24, it is easy to cool the second refrigerant. Can be recovered. Thereby, the low temperature 2nd refrigerant | coolant is heated to about ambient temperature by the cold energy collection | recovery of the 2nd internal heat exchanger 33. FIG. For this reason, the heat loss by the suction piping of the 2nd compressor 21 can be suppressed.

In addition, since the first internal heat exchanger 32 performs heat exchange between the first refrigerant flowing out from the third internal heat exchanger 34 and the second refrigerant flowing out from the second internal heat exchanger 33, the second refrigerant The cold heat can be easily recovered.

Further, the first pressure reducing device 13 arranged in the previous stage of the first evaporator 14 is composed of a capillary tube, and the first pressure reducing device 13 functions as a heat exchange pipe for the first internal heat exchanger 32 or the third internal heat exchanger 34. Therefore, the number of parts can be reduced and the cost of the refrigerator-freezer 1 can be reduced.

Further, since the second decompression device 23 arranged in the front stage of the second evaporator 24 is composed of a capillary tube, and the second decompression device 23 functions as a heat exchange pipe of the second internal heat exchanger 33, the number of parts is reduced. Thus, the cost of the refrigerator-freezer 1 can be reduced.

In the first to fourth embodiments, the same refrigerant such as isobutane is used as the first and second refrigerants, but different refrigerants may be used. At this time, the boiling point of the first refrigerant may be higher than the boiling point of the second refrigerant. Thereby, since the vapor density of the second refrigerant is higher than that of the first refrigerant and the performance of the second refrigeration cycle 20 can be further improved, it is further preferable.

For example, it can be easily realized by using isobutane (boiling point −12 ° C.) as the first refrigerant and propane (boiling point −40.09 ° C.) or carbon dioxide (boiling point −78.5 ° C.) as the second refrigerant. . All of these refrigerants are natural refrigerants that use substances that exist in large quantities in nature. Therefore, the environmental load of the refrigerator-freezer 1 can be further reduced by increasing the cooling efficiency of the refrigeration cycle using the natural refrigerant.

Next, FIG. 15 is a side sectional view showing the refrigerator-freezer of the fifth embodiment. The main body of the refrigerator-freezer 1 has a heat insulating box 3. In the upper part of the heat insulating box 3, a refrigerator compartment 2 for storing stored items in a refrigerator is arranged. The front surface of the refrigerator compartment 2 is opened and closed by a rotating heat insulating door 2a.

A freezing room 4 for freezing and storing stored items is disposed below the refrigerating room 2 through a heat insulating wall 7. The freezer compartment 4 is partitioned by a partition wall 8 disposed at the front, and storage cases 4c and 4d are disposed vertically. The front surface of the freezer compartment 4 is opened and closed by drawer-type heat insulating doors 4a and 4b respectively integrated with the storage cases 4c and 4d.

The heat insulating wall 7 has the same level of heat insulating performance as the peripheral wall (upper wall, bottom wall, side wall, and back wall) of the heat insulating box 3. Thereby, heat exchange between the refrigerator compartment 2 and the freezer compartment 4 is suppressed.

A first machine room 5 in which the first compressor 11 is arranged is provided at the upper rear of the refrigerator compartment 2. A second machine room 6 in which a second compressor 21 is arranged is provided at the lower rear of the freezer room 4. The first and second compressors 11 and 21 operate the first and second refrigeration cycles 10 and 20 (see FIG. 16), respectively.

A first evaporator 14 connected to the first compressor 11 is disposed on the back of the refrigerator compartment 2, and a refrigerator refrigerator 15 is disposed above the first evaporator 14. A second evaporator 24 connected to the second compressor 21 is disposed on the back surface of the freezer compartment 4, and a freezer compartment blower 25 is disposed above the second evaporator 24.

The cold air cooled by exchanging heat with the first evaporator 14 is discharged to the refrigerator compartment 2 by the refrigerator compartment fan 15. The cold air flows through the refrigerator compartment 2 and returns to the first evaporator 14. Thereby, the refrigerator compartment 2 is cooled. The cold air cooled by exchanging heat with the second evaporator 24 is discharged to the freezer compartment 4 by the freezer blower 25. The cold air discharged into the freezer compartment 4 flows through the freezer compartment 4 and returns to the second evaporator 24. Thereby, the freezer compartment 4 is cooled.

FIG. 16 is a rear perspective view showing the piping of the refrigerator 1. FIG. 17 shows the refrigeration cycle of the refrigerator 1. The refrigeration cycle 30 of the refrigerator 1 is a cascade type dual refrigeration cycle in which the first and second refrigeration cycles 10 and 20 are connected by an intermediate heat exchanger 31. In FIG. 16, the first refrigeration cycle 10 is indicated by a solid line, and the second refrigeration cycle 20 is indicated by a broken line.

The first refrigeration cycle 10 operated by the first compressor 11 has a first radiator 12, a first dryer 16, a first decompressor 13, and a first evaporator 14 connected by a refrigerant pipe 10a. A first refrigerant such as isobutane flows in the direction of arrow S1 in the refrigerant pipe 10a. That is, the first refrigerant circulates through the first compressor 11, the first radiator 12, the first dryer 16, the first decompressor 13, the first evaporator 14, and the first compressor 11 in this order.

The first radiator 12 is formed by fixing the refrigerant pipe 10a to a metal plate covering the back and side surfaces of the main body, and radiates heat to the outside air. Moreover, the 1st heat radiator 12 has the front-surface part 12a and the evaporation part 12b. The front surface portion 12a is embedded in the front portion of the partition wall 8 or the like (see FIG. 15), and prevents condensation at the opening peripheral edge portion of the freezer compartment 4 that contacts the heat insulating doors 4a and 4b by heat radiation. The evaporating unit 12b is disposed in the first machine room 6 and evaporates drain water collected in an evaporating dish (not shown) by heat radiation. Thereby, dew condensation prevention and evaporation of drain water can be performed efficiently by the 1st radiator 12 of the high temperature 1st freezing cycle 10.

The first dryer 16 is disposed in the second machine room 6 and dehumidifies the first refrigerant flowing into the first pressure reducing device 13. The first decompression device 13 includes a capillary tube, and forms a first internal heat exchanger 32 to exchange heat with the second refrigerant that has flowed out of the second evaporator 24.

The second refrigeration cycle 20 operated by the second compressor 21 has a second radiator 22, a second dryer 26, a second decompressor 23, and a second evaporator 24 connected by a refrigerant pipe 20a. A second refrigerant such as isobutane flows in the direction of the arrow S2 in the refrigerant pipe 20a. That is, the second refrigerant circulates through the second compressor 21, the second radiator 22, the second dryer 26, the second decompressor 23, the second evaporator 24, and the second compressor 21 in this order.

The second radiator 22 is formed by fixing the refrigerant tube 20a to a metal plate covering the back surface of the main body, and radiates heat to the outside air. The second dryer 26 is disposed in the first machine room 5. The second decompression device 23 is composed of a capillary tube, and forms a second internal heat exchanger 33 to exchange heat with the second refrigerant flowing out from the second evaporator 24. An accumulator 28 for separating gas and liquid is provided on the refrigerant outflow side of the second evaporator 24.

The intermediate heat exchanger 31 includes a heat exchange part 31 a provided in the first refrigeration cycle 10 and a heat exchange part 31 c provided in the second refrigeration cycle 20. The heat exchanging part 31 a is arranged downstream of the first evaporator 14, and the heat exchanging part 31 c is arranged downstream of the second radiator 22. The first and second heat exchange portions 31a and 31b are formed adjacent to each other and are formed so as to be able to exchange heat via a boundary wall.

The intermediate heat exchanger 31 is formed of a double pipe having an inner pipe and an outer pipe embedded in the back wall of the heat insulating box 3 (see FIG. 15), and is formed into a U-shaped pipe that extends in the vertical direction and bends at the lower end. Is done. The first refrigerant flows through the inner pipe of the double pipe to form the heat exchange part 31a, and the second refrigerant flows through the outer pipe to form the heat exchange part 31c. The heat exchange part 31a has a refrigerant inlet 31g and a refrigerant outlet 31h formed at the upper end. Similarly, in the heat exchange part 31c, the refrigerant inlet 31e and the refrigerant outlet 31f are formed at the upper end, and the flow direction of the heat exchange part 31a and the refrigerant is reversed.

The first and second refrigeration cycles 10 and 20 are provided with first and second internal heat exchangers 32 and 33, respectively. The first and second internal heat exchangers 32 and 33 are embedded in the back wall of the heat insulating box 3 (see FIG. 15). The second internal heat exchanger 33 is formed so that the second decompression device 23 and the heat exchange part 33b provided in the second refrigeration cycle 20 are adjacent to each other and can exchange heat via a boundary wall. In the present embodiment, the second internal heat exchanger 33 is formed by welding the capillary tube forming the decompression device 23 and the refrigerant tube forming the heat exchange part 33b.

The heat exchanging part 33b is arranged at the rear stage of the second evaporator 24, and the low temperature second refrigerant flowing out from the second evaporator 24 circulates therethrough. The refrigerant inflow side of the second decompression device 23 is provided in the upper part of the main body near the first compressor 11. Thereby, the 2nd internal heat exchanger 33 is extended and formed from the upper part of a main-body part to the lower part where the 2nd evaporator 24 is arranged, and can ensure long heat exchange length.

The first internal heat exchanger 32 is adjacent to the first pressure reducing device 13 and the heat exchanging part 32b provided in the second refrigeration cycle 20, and is formed to be able to exchange heat with each other through a wall surface. In the present embodiment, the first internal heat exchanger 32 is formed by welding the capillary tube forming the decompression device 13 and the refrigerant tube forming the heat exchange part 32b.

The heat exchanging part 32b is arranged at the rear stage of the heat exchanging part 33b of the second internal heat exchanger 33, and the low temperature second refrigerant after flowing out of the second evaporator 24 circulates. The refrigerant inflow side of the first decompression device 13 is provided in the lower part of the main body portion close to the second compressor 21. Thereby, the 1st internal heat exchanger 32 is extended and formed from the lower part of a main-body part to the upper part by which the 1st evaporator 14 is arranged, and can ensure long heat exchange length.

In the refrigerator-freezer 1 configured as described above, the first and second refrigerants circulate through the refrigerant tubes 10a and 20a by driving the first and second compressors 11 and 21. The first and second compressors 11 and 21 compress the first and second refrigerants to high temperature and high pressure, and the first and second decompression devices 13 and 23 decompress and expand the first and second refrigerants at low temperature and low pressure. To.

Accordingly, the first and second refrigeration cycles 10 and 20 until the first and second refrigerants flow out of the first and second compressors 11 and 21 and flow into the first and second decompression devices 13 and 23. It becomes the high temperature part. The low temperature of the first and second refrigeration cycles 10 and 20 until the first and second refrigerant flows out of the first and second decompression devices 13 and 23 and flows into the first and second compressors 11 and 21. Part.

The first high-temperature and high-pressure refrigerant compressed by the first compressor 11 is deprived of heat by the first radiator 12 and condensed. The first refrigerant liquefied by the first radiator 12 is dehumidified by the first dryer 16 to remove moisture. The first refrigerant that has flowed out of the first dryer 16 is decompressed and expanded by the first decompressor 13 and becomes low-temperature wet steam having a low dryness. At this time, the first refrigerant is further lowered in temperature by the first internal heat exchanger 32 taking heat away from the second refrigerant in the low temperature portion of the second refrigeration cycle 20.

The first refrigerant that has become low-temperature wet steam flows into the first evaporator 14, takes heat away from the cold air in the refrigerator compartment 2, and evaporates to become wet steam with higher dryness. The first refrigerant in the wet vapor state flowing out from the first evaporator 14 flows into the intermediate heat exchanger 31 and evaporates while taking heat from the second refrigerant in the high temperature part of the second refrigeration cycle, and becomes superheated vapor. The first refrigerant that has become superheated steam returns to the first compressor 11. As a result, the first refrigerant circulates and the first refrigeration cycle 10 is operated.

The high-temperature and high-pressure second refrigerant compressed by the second compressor 21 is deprived of ambient air by the second radiator 22. The second refrigerant lowered in temperature by the second radiator 22 flows into the intermediate heat exchanger 31 and is deprived of heat by the first refrigerant in the low temperature part of the first refrigeration cycle 10 to be condensed. The second refrigerant liquefied by the second radiator 22 and the intermediate heat exchanger 31 is dehumidified by the second dryer 26 to remove moisture.

The second refrigerant that has flowed out of the second dryer 26 is decompressed and expanded by the second decompression device 23, and becomes low-temperature wet steam having a low dryness. At this time, the second refrigerant is further lowered in temperature by the second internal heat exchanger 32 where heat is taken away by the second refrigerant in the low temperature portion of the second refrigeration cycle 20. The second refrigerant that has become low-temperature wet steam flows into the second evaporator 24, takes heat from the cold air in the freezer compartment 4 and evaporates to become wet steam.

The second refrigerant in the wet vapor state flowing out from the second evaporator 24 is guided to the second internal heat exchanger 33 and the first internal heat exchanger 32, and takes heat from the high-temperature second refrigerant and the first refrigerant and overheats. It becomes steam. The second refrigerant that has become superheated steam returns to the second compressor 21. As a result, the second refrigerant circulates and the second refrigeration cycle 20 is operated.

In addition, the rotation speeds of the first and second compressors 11 and 21 are controlled by the inverter. Thereby, the temperature levels of the first evaporator 14 and the second evaporator 24 are controlled so as to correspond to the temperatures of the refrigerator compartment 2 and the freezer compartment 4, respectively.

According to this embodiment, as in the first embodiment, the refrigeration cycle 30 is configured as a cascade-type dual refrigeration cycle in which the first and second refrigeration cycles 10 and 20 are connected by the intermediate heat exchanger 31, and the first The refrigerator compartment 2 is cooled by the first evaporator 14 and the freezer compartment 4 is cooled by the second evaporator 24. For this reason, the temperature difference between the first evaporator 14 and the refrigerator compartment 2 can be reduced. Moreover, since the compression ratio of the 1st, 2nd compressors 11 and 21 becomes small, the 1st and 2nd compressors 11 and 21 can be drive | operated with high efficiency. Therefore, the COP of the refrigeration cycle 30 is improved, and the power consumption of the refrigerator-freezer 1 can be reduced.

Moreover, since it cools with the 1st, 2nd evaporators 14 and 24 provided in the 1st, 2nd freezing cycle 10 and 20 according to the temperature of the refrigerator compartment 2 and the refrigerator compartment 4, respectively, it is a refrigerator refrigerator compared with the past. 1 can achieve a significant reduction in power consumption.

In addition, the first machine room 5 in which the first compressor 11 is arranged is arranged at the upper part of the main body part, and the second machine room 6 in which the second compressor 21 is arranged is arranged in the lower part of the main body part. The first and second compressors 11 and 21 serving as point sound sources are arranged apart from each other. The sound pressure level of a point sound source decreases as the distance increases. For example, when the distance is doubled, the sound pressure level is reduced by about 6 dB. For this reason, when approaching one sound source, since it is away from the other sound source, the level of noise felt by the user is reduced.

Also, since the first and second compressors 11 and 21 are arranged in different rooms, it is difficult for sounds having the same phase and sound having the same frequency to be generated. Thereby, while the sound pressure which superimposed the sound of the 1st, 2nd compressors 11 and 21 falls, generation | occurrence | production of a wave | undulation can be reduced. Therefore, the noise of the refrigerator-freezer 1 can be reduced.

Even if the first machine room 5 is arranged at the lower part of the main body and the second machine room 6 is arranged at the upper part of the main body, the noise can be similarly reduced.

In addition, the first machine room 5 and the refrigerator compartment 2 are provided in the upper part of the main body, the first evaporator 14 is arranged behind the refrigerator compartment 2, and the second machine room 6 and the freezer compartment 4 are provided in the lower part of the main body part. Two evaporators 24 are arranged behind the freezer compartment 4. The intermediate heat exchanger 31 extends vertically and is bent in the vertical direction at a position away from the first compressor 11, and the refrigerant inlets 31 g and 31 e and the refrigerant outlet are formed in the upper part of the main body near the first machine chamber 5. 31h and 31f are provided.

Thereby, the connection length of the 1st evaporator 14, the intermediate heat exchanger 31, and the 1st compressor 11 is shortened. Therefore, the piping length of the first refrigeration cycle 10 can be shortened, and the cooling efficiency of the first refrigeration cycle 10 can be further improved.

In addition, the 1st machine room 5 and the refrigerator compartment 2 may be distribute | arranged to the main-body part lower part, and the 2nd machine room 6 and the freezer compartment 4 may be distribute | arranged to the upper part of a main-body part. At this time, the intermediate heat exchanger 31 may be bent at the upper end, and the refrigerant inlets 31g and 31e and the refrigerant outlets 31h and 31f may be provided at the lower end. That is, the refrigerator compartment 2 and the freezer compartment 4 are arranged side by side vertically, and the first and second machine compartments 5 and 6 are disposed in the vicinity of the refrigerator compartment 2 and the freezer compartment 4, respectively. The intermediate heat exchanger 31 may be bent at a position away from the first compressor 11, and the refrigerant inlets 31 g and 31 e and the refrigerant outlets 31 h and 31 f may be provided in the vicinity of the first machine chamber 5.

In addition, since the first internal heat exchanger 32 that performs heat exchange between the first decompression device 13 and the low-temperature second refrigerant that has flowed out of the second evaporator 24 is provided, the first internal heat exchanger 32 that flows into the first evaporator 14 is provided. The enthalpy of one refrigerant can be reduced. Therefore, the cooling capacity of the first refrigerant flowing into the first evaporator 14 can be further improved.

Similarly, since the second internal heat exchanger 33 that performs heat exchange between the second decompression device 23 and the low-temperature second refrigerant that has flowed out of the second evaporator 24 is provided, it flows into the second evaporator 24. The enthalpy of the second refrigerant can be reduced. Therefore, the cooling capacity of the second refrigerant flowing into the second evaporator 24 can be further improved.

At this time, the refrigerant inflow side of the first decompression device 13 is arranged at the lower part of the main body, and the first internal heat exchanger 32 extends upward and is connected to the first evaporator 14. Further, the refrigerant inflow side of the second decompression device 23 is disposed on the upper portion of the main body, and the first internal heat exchanger 32 extends downward and is connected to the second evaporator 14. Accordingly, the heat exchange length of the first and second internal heat exchangers 32 and 33 can be increased, and the enthalpies of the first and second refrigerants flowing into the first and second evaporators 14 and 24 can be reliably reduced. Can do.

In addition, when the 1st compressor 11 and the 1st evaporator 14 are distribute | arranged to the lower part of a main-body part, and the 2nd compressor 21 and the 2nd evaporator 24 are distribute | arranged to an upper part of a main-body part, the 1st decompression device 13 The refrigerant inflow side may be provided in the upper part of the main body, and the refrigerant inflow side of the second decompression device 23 may be provided in the lower part of the main body. That is, the refrigerant inflow side of the first decompression device 13 may be provided in the vicinity of the second compressor 21, and the refrigerant inflow side of the second decompression device 23 may be provided in the vicinity of the first compressor 11.

Moreover, since the refrigerant | coolant outflow port 31f of the heat exchange part 31c of the intermediate heat exchanger 31 is provided in a main-body part upper part, the connection of the intermediate heat exchanger 31 and the 2nd pressure reduction apparatus 23 is shortened, and the 2nd freezing cycle 20 of FIG. The cooling efficiency can be further improved. When the 2nd compressor 21 and the 2nd evaporator 24 are arranged at the main-body part upper part, it is good to provide the refrigerant | coolant outflow port 31f of the heat exchange part 31c in a main-body part lower part. That is, the refrigerant outlet 31f of the heat exchange part 31c may be provided in the vicinity of the first compressor 11.

The first machine room 5 and the freezer room 4 may be arranged at the lower part of the main body, and the second machine room 6 and the refrigerator room 2 may be arranged at the upper part of the main body.

In addition, since the first dryer 16 is disposed in the second machine room 6 and the second dryer 26 is disposed in the first machine room 5, the piping between the first dryer 16 and the first internal heat exchanger 32 can be shortened. The piping between the second dryer 26 and the intermediate heat exchanger 31 can be shortened.

Further, since the second dryer 26 is covered with the heat insulating material 50, the temperature rise of the second refrigerant in the low-temperature second refrigeration cycle 20 due to heat intrusion from the first machine chamber 5 can be prevented.

Further, the intermediate heat exchanger 31 is formed of a double pipe, and the first refrigerant flows through the inner pipe and the second refrigerant flows through the outer pipe. Therefore, the first refrigerant can easily come into contact with the inner pipe serving as a heat exchange surface. Become. Thereby, evaporation of the first refrigerant can be promoted and the first refrigerant can be returned to the first compressor 11. At this time, the second refrigerant comes into contact with the inner tube and the outer tube and condenses due to heat radiation. Moreover, since the flow direction of the 1st, 2nd refrigerant | coolant which distribute | circulates an inner pipe and an outer pipe was made into the reverse direction, the sensible heat by the 1st refrigerant | coolant after evaporation can be efficiently transmitted to the 2nd refrigerant | coolant of an inflow side. Therefore, the cooling efficiency of the refrigeration cycle 30 can be improved.

Further, since the second radiator 22 is provided between the second compressor 21 and the intermediate heat exchanger 31, the heat radiation temperature of the entire first and second refrigeration cycles 10 and 20 can be further lowered. In addition, the second refrigerant circulates through the second radiator 22 before the heat is taken away by the first refrigerant by the intermediate heat exchanger 31. Thereby, since the 2nd refrigerant | coolant after heat-exchanging with the 2nd heat radiator 22 and thermally radiating is cooled by the intermediate heat exchanger 31, heat exchange can be performed more efficiently.

Moreover, since the 1st, 2nd internal heat exchangers 32 and 33 were embed | buried in the back wall of the heat insulation box 3, and the 2nd heat radiator 22 was arrange | positioned in the back surface of a main-body part, a complicated piping is concentrated on the back surface. be able to. Thereby, a vacuum heat insulating material can be easily arrange | positioned in the heat insulation box 3, and the heat insulation performance of the heat insulation box 3 can be improved.

In addition, since the intermediate heat exchanger 31 is embedded in the back wall of the heat insulating box 3, the relatively low temperature intermediate heat exchanger 31, the second radiator 22, and the first and second internal heat exchangers 32 and 33 are provided. Concentrated on the back. Therefore, the heat loss of the refrigerator-freezer 1 can be reduced.

Also, the accumulator 28 is installed on the refrigerant outflow side of the second evaporator 24, and no accumulator is installed on the refrigerant outflow side of the first evaporator 14. Since the intermediate heat exchanger 31 is disposed downstream of the first evaporator 14, the first refrigerant can be reliably evaporated. For this reason, even if an accumulator is omitted, it is possible to prevent liquid refrigerant from entering the first compressor 11. Therefore, the cost can be reduced.

Moreover, since the heat insulation wall 7 which partitions the refrigerator compartment 2 and the freezer compartment 4 was given the heat insulation performance of the same level as the surrounding wall (upper wall, bottom wall, side wall, and back wall) of the heat insulation box 3, from the refrigerator compartment 2 Heat intrusion into the freezer compartment 4 can be reliably prevented. Thereby, the low temperature cool air cooled by the second refrigeration cycle 20 can be used only for cooling the freezer compartment 4. Therefore, the power consumption of the refrigerator-freezer 1 can be further reduced.

Moreover, since a part of heat radiation of the 1st heat radiator 12 is utilized for the prevention of dew condensation by the front part 12a, and it uses for the drain water process of the refrigerator-freezer 1 by the evaporation part 12b, the 1st heat radiation of the high temperature 1st freezing cycle 10 is carried out. The vessel 12 can efficiently perform dew condensation prevention and drain water treatment.

In the present embodiment, the same refrigerant such as isobutane is used for the first and second refrigerants, but different refrigerants may be used. At this time, the boiling point of the first refrigerant may be higher than the boiling point of the second refrigerant. Thereby, since the vapor density of the second refrigerant is higher than that of the first refrigerant and the performance of the second refrigeration cycle 20 can be further improved, it is further preferable.

For example, it can be easily realized by using isobutane (boiling point −12 ° C.) as the first refrigerant and propane (boiling point −40.09 ° C.) or carbon dioxide (boiling point −78.5 ° C.) as the second refrigerant. . All of these refrigerants are natural refrigerants that use substances that exist in large quantities in nature. Therefore, the environmental load of the refrigerator-freezer 1 can be further reduced by increasing the cooling efficiency of the refrigeration cycle using the natural refrigerant.

In the refrigerator-freezer in which the first and second refrigeration cycles 10 and 20 are independently operated by the first and second compressors 11 and 21 with the intermediate heat exchanger 31 omitted, the first and second machine rooms 5 and 6 are operated. The noise can be reduced by dispersing the components in the upper and lower parts of the main body.

Next, the refrigerator-freezer of 6th Embodiment is demonstrated. The refrigerator-freezer 1 of this embodiment has the same structure as the first embodiment shown in FIG. 1 described above, and the configuration of the refrigeration cycle 30 is different.

FIG. 18 shows the refrigeration cycle of the refrigerator-freezer 1 of the present embodiment. The refrigerator-freezer 1 has a first refrigeration cycle 10 operated by a first compressor 11 and a second refrigeration cycle 20 operated by a second compressor 21. The first refrigeration cycle 10 includes a first radiator 12, a first decompressor 13, and a first evaporator 14 connected by a refrigerant pipe 10a. A first refrigerant such as isobutane flows in the direction of arrow S1 in the refrigerant pipe 10a. That is, the first refrigerant circulates through the first compressor 11, the first radiator 12, the first decompressor 13, the first evaporator 14, and the first compressor 11 in this order.

Also, a defrosting heat exchanger 35 is arranged in parallel with the first radiator 12. A three-way valve 36 for switching the flow path is provided on the refrigerant inflow side of the first radiator 12, and the refrigerant pipe 10 a branched by the three-way valve 36 is connected to the defrosting heat exchanger 35. A check valve 37 is provided on the refrigerant outflow side of the defrosting heat exchanger 35. The check valve 37 is arranged in the vicinity of the junction 10b between the refrigerant outflow side of the first radiator 12 and the refrigerant outflow side of the defrosting heat exchanger 35, and is arranged away from the defrosting heat exchanger 35.

The first refrigerant flows as indicated by the arrow S1 'by switching the three-way valve 36 to the defrosting heat exchanger 35 side. Accordingly, the first refrigerant circulates through the first compressor 11, the defrosting heat exchanger 35, the first decompressor 13, the first evaporator 14, and the first compressor 11 in this order.

The second refrigeration cycle 20 operated by the second compressor 21 has a second radiator 22, a second decompression device 23, and a second evaporator 24 connected by a refrigerant pipe 20a. A second refrigerant such as isobutane flows in the direction of the arrow S2 in the refrigerant pipe 20a. That is, the second refrigerant circulates through the second compressor 21, the second radiator 22, the second decompressor 23, the second evaporator 24, and the second compressor 21 in this order.

The defrosting heat exchanger 35 and the second evaporator 24 are formed so as to be able to exchange heat with each other. FIG. 19 shows a detailed view of the defrosting heat exchanger 35 and the second evaporator 24. The defrosting heat exchanger 35 and the refrigerant pipes 10 a and 20 a of the second evaporator 24 meander in close proximity and are connected by a large number of fins 37. Thereby, heat exchange between the defrosting heat exchanger 35 and the second evaporator 24 is easily performed via the fins 37. The refrigerant pipes 10 a and 20 a may be provided adjacent to each other, and may be formed so as to be able to exchange heat with each other via a boundary wall between the defrosting heat exchanger 35 and the second evaporator 24.

Further, the cross-sectional area of the first refrigerant pipe 10a of the defrosting heat exchanger 35 is formed to be ½ or less of the cross-sectional area of the first refrigerant pipe 10a of the first evaporator 14. Thereby, when the three-way valve 36 is switched to the first radiator 12 side, the amount of the first refrigerant remaining in the defrosting heat exchanger 35 can be reduced.

The first and second radiators 12 and 22 are provided by being joined to the back side of a metal plate (not shown) that covers the side surface and back surface of the refrigerator-freezer 1. The first and second radiators 12 and 22 extend in the heat insulating box 6 and are arranged in the vicinity of the doors 2a, 3a, and 4a of the heat insulating walls 7 and 8. Thereby, while ensuring sufficient heat dissipation area, the dew condensation of door 2a, 3a, 4a vicinity can be prevented.

The first and second refrigeration cycles 10 and 20 are provided with second and third internal heat exchangers 33 and 34 similar to those in the fourth embodiment (see FIG. 12), and the first internal heat exchanger 32 (see FIG. 12) is omitted.

The second internal heat exchanger 33 is adjacent to the heat exchanging part 33a arranged at the rear stage of the second radiator 22 and the heat exchanging part 33b arranged at the rear stage of the second evaporator 24, and mutually passes through the boundary wall. It is formed to be heat exchangeable. The high-temperature second refrigerant that has flowed out of the second radiator 22 flows through the heat exchange unit 33a, and the low-temperature second refrigerant that has flowed out of the second evaporator 24 flows through the heat exchange unit 33b. In the case where the second decompression device 23 is made of a capillary tube, the heat exchanging portion 33a may also serve as the second decompression device 23.

The third internal heat exchanger 34 is adjacent to the heat exchanging part 34a arranged at the rear stage of the first radiator 12 and the heat exchanging part 34b arranged at the rear stage of the first evaporator 14, and mutually passes through the boundary wall. It is formed to be heat exchangeable. The high temperature first refrigerant that has flowed out of the first radiator 12 circulates in the heat exchange part 34a, and the low temperature first refrigerant that has flowed out of the first evaporator 14 circulates in the heat exchange part 34b. When the first pressure reducing device 13 is formed of a capillary tube, the heat exchanging portion 34 a may also serve as the first pressure reducing device 13.

In the refrigerator 1 having the above configuration, when the refrigerator compartment 2, the vegetable compartment 3 and the freezer compartment 4 are cooled, the first and second compressors 11 and 21 drive the refrigerant pipes 10a and 20a so that the first and second refrigerants circulate. . The first and second compressors 11 and 21 compress the first and second refrigerants to high temperature and high pressure, and the first and second decompression devices 13 and 23 decompress and expand the first and second refrigerants at low temperature and low pressure. To.

The first high-temperature and high-pressure refrigerant compressed by the first compressor 11 is deprived of heat by the first radiator 12 and condensed. The first refrigerant flowing out of the first radiator 12 is prevented from flowing into the defrosting heat exchanger 35 by the check valve 37. At this time, the check valve 37 is arranged away from the defrosting heat exchanger 35 and in the vicinity of the junction 10b. For this reason, the temperature rise of the second evaporator 24 due to heat transfer from the high-temperature first refrigerant flowing out of the first radiator 12 through the first refrigerant tube 10a can be reduced.

The first refrigerant liquefied by the first radiator 12 flows into the third internal heat exchanger 34, exchanges heat with the first refrigerant that flows out of the first evaporator 14, and is further cooled. The first refrigerant in the liquid state cooled by the third internal heat exchanger 34 and having a high degree of supercooling flows into the first decompression device 13. The first refrigerant is decompressed and expanded by the first decompression device 13, and becomes a low-temperature wet steam having a low dryness.

The first refrigerant that has become low-temperature wet steam flows into the first evaporator 14, takes heat away from the cold air in the refrigerator compartment 2, and evaporates to become wet steam with higher dryness. The first refrigerant in the wet vapor state flowing out of the first evaporator 14 flows into the third internal heat exchanger 34, evaporates while taking heat from the high-temperature first refrigerant flowing out of the first radiator 12, and superheated steam. It becomes. The first refrigerant that has become superheated steam returns to the first compressor 11. Thereby, a 1st refrigerant | coolant circulates, the 1st freezing cycle 10 is drive | operated, and the refrigerator compartment 2 and the vegetable compartment 3 are cooled.

The high-temperature and high-pressure second refrigerant compressed by the second compressor 21 is condensed by being deprived of heat to the surrounding air by the second radiator 22. The second refrigerant liquefied by the second radiator 22 flows into the second internal heat exchanger 33, exchanges heat with the second refrigerant that has flowed out of the second evaporator 24, and is further cooled. The second refrigerant in a liquid state cooled by the second internal heat exchanger 33 and having a high degree of supercooling flows into the second decompression device 23. The second refrigerant is decompressed and expanded by the second decompression device 13, and becomes low-temperature wet steam having a low dryness.

The second refrigerant that has become low-temperature wet steam flows into the second evaporator 24, takes heat from the cold air in the freezer compartment 4, evaporates, and becomes wet steam with higher dryness. The second refrigerant in the wet vapor state flowing out from the second evaporator 24 flows into the second internal heat exchanger 33, evaporates while taking heat from the high-temperature second refrigerant flowing out from the second radiator 22, and superheated steam. It becomes. The second refrigerant that has become superheated steam returns to the second compressor 21. As a result, the second refrigerant circulates, the second refrigeration cycle 10 is operated, and the freezer compartment 4 is cooled.

FIG. 20 is a flowchart showing the operation of the second evaporator 24 during defrosting. In step # 11, the second compressor 21 is stopped to defrost the second evaporator 24. In step # 12, the first compressor 11 is stopped. In step # 13, the three-way valve 36 is switched to the defrosting heat exchanger 35 side.

In Step # 14, the process waits until a predetermined time elapses after the first compressor 11 is stopped. Thereby, the temperature of the refrigerator compartment 2 and the vegetable compartment 3 rises. When the predetermined time has elapsed and the refrigerator compartment 2 and the vegetable compartment 3 are close to the upper limit of the set temperature, the process proceeds to step # 15. The three-way valve 36 may be switched to the defrosting heat exchanger 35 side after the predetermined time has elapsed. Further, the waiting period may not depend on time. That is, a temperature sensor may be provided in the refrigerator compartment 2 or the vegetable compartment 3, and after waiting for a predetermined period until the upper limit of the set temperature is detected by the temperature sensor, the process may proceed to step # 15.

In step # 15, the first compressor 11 is driven. Thereby, the 1st freezing cycle 10 is drive | operated and the 2nd evaporator 24 is heated up by heat exchange with the heat exchanger 35 for a defrost of a high temperature part, and a defrost is performed. Moreover, the refrigerator compartment 2 and the vegetable compartment 3 are cooled. By preheating the refrigerator compartment 2 and the vegetable compartment 3 in step # 14, overcooling of the refrigerator compartment 2 and the vegetable compartment 3 at the time of defrosting can be prevented.

In step # 16, it waits until a predetermined time elapses. Thereby, defrosting of the 2nd evaporator 24 advances, and when predetermined time passes and defrosting is completed, it will transfer to Step # 17. In step # 17, the three-way valve 36 is switched to the first radiator 12 side. In step # 18, the process waits until a predetermined time elapses. The first compressor 11 may be temporarily stopped when the three-way valve 36 is switched. Further, the three-way valve 36 may be switched to the first radiator 12 side after the predetermined time has elapsed.

When the predetermined time has elapsed, the process proceeds to step # 19 and the second compressor 21 is driven. Thereby, the 2nd freezing cycle 20 is drive | operated and the freezer compartment 4 is cooled.

The first evaporator 14 that cools the refrigerator compartment 2 has a higher temperature than the second evaporator 24, and therefore has a smaller amount of frost formation than the second evaporator 24. Moreover, the temperature of the air in the refrigerator compartment 2 is 0 degreeC or more. Accordingly, the first evaporator 14 can be defrosted by the heat of the air in the refrigerator compartment 2 simply by stopping the first compressor 11 and operating the refrigerator compartment fan 31. For this reason, the defrost heater 51 (refer FIG. 1) is not normally driven, but is driven at the time of abnormal frost formation.

According to the present embodiment, the first and second refrigeration cycles 10 and 20 are operated by the first and second compressors 11 and 21, respectively, and the refrigerator 2 and the freezer compartment 4 are connected by the first and second evaporators 14 and 24, respectively. Since it cools, the temperature of the 1st evaporator 14 which cools the refrigerator compartment 2 can be maintained higher than the 2nd evaporator 24, cooling efficiency improves, and the power consumption of the refrigerator-freezer 1 can be reduced.

Moreover, since the 2nd evaporator 24 of the 2nd freezing cycle 20 is defrosted with the heat | fever of the high temperature part of the 1st freezing cycle 10, the 2nd of the 1st heat radiator 12 of the 1st freezing cycle 10 and the 2nd freezing cycle 20 is carried out. The radiator 22 does not become low temperature. Therefore, dew condensation on the side and back of the refrigerator-freezer 1 can be prevented. Moreover, it is not necessary to separately provide a heater for defrosting the second evaporator 22, and the temperature rise by the heater or the like during defrosting can be suppressed. Therefore, the power consumption by defrosting can be suppressed and the power consumption of the refrigerator-freezer 1 can be kept low.

Further, since the first radiator 12 and the defrosting heat exchanger 35 are arranged in parallel and the three-way valve 36 and the check valve 37 are provided on the refrigerant inflow side and the refrigerant outflow side, respectively, the high temperature of the first refrigeration cycle 10 is provided. The refrigerator-freezer 1 which defrosts the 2nd evaporator 24 of the 2nd freezing cycle 20 with the heat of a part can be easily implement | achieved.

Further, since the check valve 37 is arranged in the vicinity of the junction 10a away from the defrosting heat exchanger 35, heat transfer from the high-temperature first refrigerant flowing out from the first radiator 12 through the first refrigerant pipe 10a. Therefore, the temperature rise of the second evaporator 24 can be reduced. Therefore, the cooling efficiency of the refrigerator-freezer 1 can be improved.

Moreover, since the 1st compressor 11 was stopped for the predetermined period before the defrost of the 2nd evaporator 24, the refrigerator compartment 2 and the vegetable compartment 3 were heated beforehand, and the excess of the refrigerator compartment 2 and the vegetable compartment 3 at the time of a defrost was carried out. Cooling can be prevented.

Further, since the cross-sectional area of the first refrigerant pipe 10a of the defrosting heat exchanger 35 is formed to be ½ or less of the cross-sectional area of the first refrigerant pipe 10a of the first evaporator 14, After the defrosting is completed and the three-way valve 36 is switched to the first radiator 12 side, a large amount of the first refrigerant does not remain in the defrosting heat exchanger 35. Therefore, the amount of refrigerant sealed in the first refrigeration cycle 10 can be suppressed.

In the first to sixth embodiments, the refrigerator may be provided with a dual refrigeration cycle in which the first and second evaporators 14 and 24 are respectively disposed in the first and second cooling chambers having different room temperatures. Anything can be applied as well. In other words, the present invention can be applied to refrigeration cycle application equipment centered on a domestic refrigerator-freezer 1.

Next, FIG. 21 is a front view showing the refrigerator-freezer of the seventh embodiment. In the refrigerator-freezer 1, a refrigerating room 2 for storing stored items in a refrigerated state is arranged on an upper portion of a heat insulating box 6 that forms a main body. Below the refrigerating room 2, a freezing room 4 for freezing and storing stored items is arranged via a heat insulating wall 8. The front surface of the refrigerator compartment 2 is opened and closed by a rotating door (not shown). The front surface of the freezer compartment 4 is opened and closed by a drawer-type door (not shown) integrated with a storage case (not shown).

A machine room 5 is provided behind the freezer room 4. First and second compressors 11 and 21 (see FIG. 22) for operating first and second refrigeration cycles 10 and 20, which will be described in detail later, are disposed in the machine room 5.

In the lower part of the refrigerator compartment 2, there are provided isolation chambers 7a and 7b which are separated from the upper part by a partition wall 2a. The isolation chambers 7a and 7b are composed of an ice greenhouse and a chilled chamber maintained at a lower temperature than the upper part of the refrigerator compartment 2. The back of the refrigerator compartment 2 is covered with a metal cooling plate 14b. As will be described in detail later, the cooling plate 14b forms a first evaporator 14 (see FIG. 22) and radiates cold.

A duct (not shown) is formed behind the freezer compartment 4, and a second evaporator 24 is arranged in the duct. A freezer compartment fan 25 is provided above the second evaporator 24. The cold air heat-exchanged with the 2nd evaporator 24 by the drive of the freezer compartment fan 25 is discharged to the freezer compartment 4 from the upper discharge outlet 4a. The cold air in the freezer compartment 4 is returned to the second evaporator 24 through the lower return port 4b.

FIG. 22 is a front sectional view showing the piping of the refrigeration cycle of the refrigerator 1. The refrigerator-freezer 1 has a first refrigeration cycle 10 operated by a first compressor 11 and a second refrigeration cycle 20 operated by a second compressor 21. The first refrigeration cycle 10 includes a first radiator 12, a first decompressor 13, and a first evaporator 14 connected by a refrigerant pipe 10a. A first refrigerant such as isobutane flows in the direction of arrow S1 in the refrigerant pipe 10a. That is, the first refrigerant circulates through the first compressor 11, the first radiator 12, the first decompressor 13, the first evaporator 14, and the first compressor 11 in this order.

The second refrigeration cycle 20 operated by the second compressor 21 has a second radiator 22, a second decompression device 23, and a second evaporator 24 connected by a refrigerant pipe 20a. A second refrigerant such as isobutane flows in the direction of the arrow S2 in the refrigerant pipe 20a. That is, the second refrigerant circulates through the second compressor 21, the second radiator 22, the second decompressor 23, the second evaporator 24, and the second compressor 21 in this order.

The first evaporator 14 is formed by fixing a cooling plate 14 to a refrigerant pipe 14a through which a refrigerant flows. The cooling plate 14b is made of a metal plate having high thermal conductivity, and the front shape is formed in a substantially rectangular shape. As the material of the cooling plate 14b, aluminum, stainless steel, copper, brass, plated steel plate, or the like can be selected. In consideration of thermal conductivity, rust prevention, strength, lightness, price, etc., it is more desirable to form the cooling plate 14b from aluminum. The thickness of the cooling plate 14b is 0.5 mm to 1 mm. Thereby, while being able to have sufficient heat conductive performance, it is cheap and can obtain high intensity | strength.

In the refrigerant pipe 14a of the first evaporator 14, the refrigerant inflow side is arranged downward and the outflow side is arranged upward, and the first refrigerant circulates from below to above. Since the cooling plate 14b has a high thermal conductivity, the temperature is substantially uniform, but the refrigerant inflow side is cooler than the outflow side. For this reason, the temperature of the refrigerant pipe 14a facing the isolation chambers 7a and 7b is low, and the isolation chambers 7a and 7b can be reliably maintained at a low temperature.

The second evaporator 24 is formed by joining a large number of fins to the refrigerant pipe. Cold air flowing through a duct (not shown) on the back of the freezer compartment 4 exchanges heat with the fins to generate cold air, which is discharged into the freezer compartment 4.

The first and second radiators 12 and 22 are provided by being joined to a metal back plate (not shown) that covers the back surface of the heat insulating box 6. The first and second radiators 12 and 22 extend in the heat insulating box 6 and are arranged in front of the heat insulating wall 8. Thereby, while ensuring sufficient heat dissipation area, the dew condensation near the door of the refrigerator compartment 2 and the freezer compartment 4 can be prevented.

FIG. 23 is a block diagram showing a configuration of the refrigerator-freezer 1. The refrigerator-freezer 1 is provided with the control part 65 which controls each part. The controller 65 is connected to the first and second compressors 11 and 21, the freezer compartment fan 25, the operation panel 66, the door opening / closing detector 63, the temperature sensors 61 and 62, and the humidity sensor 64. The operation panel 66 is provided on the door of the refrigerator compartment 2 and sets the room temperature of the refrigerator compartment 2 and the freezer compartment 4.

The door opening / closing detection unit 63 detects opening / closing of the door of the refrigerator compartment 2. The temperature sensors 61 and 62 detect the indoor temperatures of the refrigerator compartment 2 and the freezer compartment 4, respectively. The first and second compressors 11 and 21 are driven by the control unit 65 based on the detected temperatures of the temperature sensors 61 and 62, and the refrigerator compartment 2 and the freezer compartment 4 are maintained at the set temperature. The humidity sensor 64 detects the humidity in the refrigerator compartment 2.

In the refrigerator-freezer 1 having the above-described configuration, the first and second refrigerants flow through the refrigerant tubes 10a and 20a by driving the first and second compressors 11 and 21 when the refrigerator compartment 2 and the freezer compartment 4 are cooled. The first and second compressors 11 and 21 compress the first and second refrigerants to high temperature and high pressure, and the first and second decompression devices 13 and 23 decompress and expand the first and second refrigerants at low temperature and low pressure. To.

The first high-temperature and high-pressure refrigerant compressed by the first compressor 11 is deprived of heat by the first radiator 12 and condensed. The first refrigerant liquefied by the first radiator 12 flows into the first decompressor 13. The first refrigerant is decompressed and expanded by the first decompression device 13, and becomes a low-temperature wet steam having a low dryness.

The first refrigerant that has become low-temperature wet steam flows into the first evaporator 14, and the cooling plate 14b takes heat from the cold air in the refrigerator compartment 2 and evaporates to become wet steam with higher dryness. The first refrigerant in the wet vapor state flowing out from the first evaporator 14 returns to the first compressor 11. As a result, the first refrigerant circulates and the first refrigeration cycle 10 is operated.

The refrigerator compartment 2 is cooled by radiation from the entire cooling plate 14b covering the back surface. Thereby, cold is not directly applied to the stored item in the refrigerator compartment 2, and drying of the stored item can be prevented.

The high-temperature and high-pressure second refrigerant compressed by the second compressor 21 is condensed by being deprived of heat to the surrounding air by the second radiator 22. The second refrigerant liquefied by the second radiator 22 flows into the second decompression device 23. The second refrigerant is decompressed and expanded by the second decompression device 13, and becomes low-temperature wet steam having a low dryness.

The second refrigerant that has become low-temperature wet steam flows into the second evaporator 24, takes heat from the cold air flowing through the duct of the freezer compartment 4, evaporates, and becomes wet steam with higher dryness. The wet second refrigerant flowing out of the second evaporator 24 returns to the second compressor 21. As a result, the second refrigerant circulates and the second refrigeration cycle 10 is operated. The freezer compartment 4 is cooled by discharging cold air heat-exchanged by the second evaporator 24.

In addition, when the door of the refrigerator compartment 2 is opened and closed, moist outside air flows into the refrigerator compartment 2. When opening / closing of the door is detected by the door opening / closing detector 63, the temperature sensor 61 and the humidity sensor 64 detect the temperature and humidity in the refrigerator compartment 2. The controller 65 derives the dew point temperature from the temperature and humidity in the refrigerator compartment 2 by calculation. And the 1st compressor 11 is driven for a predetermined period so that the inside of the refrigerator compartment 2 may become below dew point temperature.

Thereby, moisture in the outside air is condensed on the surface of the cooling plate 14b, and the cooling plate 14b becomes cloudy. When the humidity in the refrigerator compartment 2 falls below a predetermined value by the detection of the humidity sensor 64, the first compressor 11 is controlled so that the refrigerator compartment 2 reaches a set temperature. At this time, condensation on the surface of the cooling plate 14b gradually evaporates, and drying of stored items in the refrigerator compartment 2 is further prevented.

* In order to keep condensation on the surface of the cooling plate 14b, when the door is opened again, moisture from outside air flows in without flowing out. Thereby, every time the door is opened, the moisture of the moist outside air is condensed and held by the cooling plate 14b, and the moisturizing effect of the refrigerator compartment 2 can be improved.

According to the present embodiment, the first and second refrigeration cycles 10 and 20 are operated by the first and second compressors 11 and 21, respectively, and the refrigerator 2 and the freezer compartment 4 are connected by the first and second evaporators 14 and 24, respectively. The first evaporator 14 has a cooling plate 14b. Thereby, it is possible to make the temperature distribution in the refrigerating chamber 2 uniform by radiating cold heat uniformly from the cooling plate 14b covering the wall surface of the refrigerating chamber 2 while preventing the stored material from drying without directly applying cold air to the reserving material. .

Moreover, the refrigerator compartment 2 and the freezer compartment 4 can obtain sufficient cooling capacity at the time of a high load immediately after storing the stored items. In particular, the temperature of the second evaporator 24 can be lowered when the refrigerator compartment 2 is heavily loaded, and insufficient cooling of the freezer compartment 4 can be prevented. In addition, the temperature of the first evaporator 14 can be lowered when the freezer compartment 4 is under high load, and condensation in the cooling plate 14b can be maintained to maintain the humidity in the refrigerator compartment 2. Thereby, even when the freezer compartment 4 becomes a heavy load, drying of the stored matter of the refrigerator compartment 2 can be reduced more.

Also, the adiabatic compression efficiency of the compressor increases as the compression ratio decreases. Therefore, by operating the first and second refrigeration cycles 10 and 20 with the first and second compressors 11 and 21, respectively, the compression ratio is lowered, and the first and second compressors 11 and 21 are made highly efficient. Can operate.

In addition, when the door of the refrigerator compartment 2 is opened and closed, the first refrigeration cycle 10 is operated so that the first evaporator becomes equal to or lower than the dew point temperature. Therefore, moisture in the outside air is condensed and held by the cooling plate 14b. The drying of the stored product can be further reduced.

In addition, isolation chambers 7a and 7b having a temperature lower than that of the upper part are provided in the lower part of the refrigerator compartment 2, and the refrigerant flows through the refrigerant pipe 14a of the first evaporator 14 from below to above. The temperature of the cooling plate 14b made of a metal plate is uniform because of its high thermal conductivity, but the refrigerant inflow side is cooler than the outflow side. For this reason, the temperature of the refrigerant pipe 14a facing the isolation chambers 7a and 7b is low, and the isolation chambers 7a and 7b can be reliably maintained at a low temperature.

Next, FIG. 24 is a front sectional view showing the piping of the refrigeration cycle of the refrigerator-freezer of the eighth embodiment. The refrigeration cycle 30 of the refrigerator-freezer 1 of the present embodiment is configured similarly to the second embodiment shown in FIG. That is, the first and second refrigeration cycles 10 and 20 are cascade-type dual refrigeration cycles in which the intermediate heat exchanger 31 is connected. Other parts are the same as those in the first embodiment.

The intermediate heat exchanger 31 is formed such that the heat exchanging portion 31a provided in the first refrigeration cycle 10 and the heat exchanging portion 31b provided in the second refrigeration cycle 20 are adjacent to each other and can exchange heat with each other via wall surfaces. The heat exchanging part 31 a is arranged downstream of the first evaporator 14, and the heat exchanging part 31 b is arranged downstream of the second radiator 22. Therefore, heat exchange is performed between the low temperature part of the first refrigeration cycle 10 and the high temperature part of the second refrigeration cycle 20 by the intermediate heat exchanger 31.

In the refrigerator-freezer 1 configured as described above, the first and second refrigerants circulate through the refrigerant tubes 10a and 20a by driving the first and second compressors 11 and 21. The first and second compressors 11 and 21 compress the first and second refrigerants to high temperature and high pressure, and the first and second decompression devices 13 and 23 decompress and expand the first and second refrigerants at low temperature and low pressure. To.

The first high-temperature and high-pressure refrigerant compressed by the first compressor 11 is deprived of heat by the first radiator 12 and condensed. The refrigerant liquefied by the first radiator 12 flows into the first pressure reducing device 13. The first refrigerant is decompressed and expanded by the first decompression device 13, and becomes a low-temperature wet steam having a low dryness.

The first refrigerant that has become low-temperature wet steam flows into the first evaporator 14, takes heat away from the cold air in the refrigerator compartment 2, and evaporates to become wet steam with higher dryness. The first refrigerant in the wet vapor state flowing out from the first evaporator 14 flows into the intermediate heat exchanger 31 and evaporates while taking heat from the second refrigerant in the high temperature part of the second refrigeration cycle to become superheated vapor. The first refrigerant that has become superheated steam returns to the first compressor 11. As a result, the first refrigerant circulates and the first refrigeration cycle 10 is operated.

The high-temperature and high-pressure second refrigerant compressed by the second compressor 21 is deprived of ambient air by the second radiator 22. The second refrigerant lowered in temperature by the second radiator 22 flows into the intermediate heat exchanger 31 and is deprived of heat by the first refrigerant in the low temperature part of the first refrigeration cycle 10 to be condensed. The liquefied second refrigerant flows into the second decompression device 23.

The second refrigerant is decompressed and expanded by the second decompression device 23, and becomes low-temperature wet steam. The second refrigerant that has become low-temperature wet steam flows into the second evaporator 24, takes heat from the cold air in the freezer compartment 4 and evaporates to become wet steam. The wet second refrigerant flowing out of the second evaporator 24 returns to the second compressor 21. As a result, the second refrigerant circulates and the second refrigeration cycle 20 is operated.

The second compressor 21 is driven after the temperature of the intermediate heat exchanger 31 is lowered after the first compressor 11 is driven. And the temperature of the refrigerator compartment 2 and the freezer compartment 4, and the temperature difference of the heat exchange parts 31a and 31b of the intermediate | middle heat exchanger 31 are monitored, and the 1st, 2nd compressor 11 is controlled by inverter control so that these may become predetermined value. , 21 is controlled.

According to this embodiment, the same effect as that of the seventh embodiment can be obtained. Furthermore, since the intermediate heat exchanger 31 is provided, the heat of the high temperature part of the second refrigeration cycle 20 is absorbed by the intermediate heat exchanger 31. Thereby, the temperature of the second evaporator 24 can be further lowered than that of the intermediate heat exchanger 31, and low-temperature cold air can be easily generated.

In the present embodiment, the first and second refrigerants flowing through the first and second refrigeration cycles 10 and 20 are made of isobutane, but different refrigerants may be used. At this time, it is more desirable to make the boiling point of the second refrigerant lower than the boiling point of the first refrigerant. Thereby, the vapor density of the second refrigerant is higher than that of the first refrigerant, and the performance of the second refrigeration cycle 20 can be further improved. For example, it can be easily realized by using isobutane (boiling point −12 ° C.) as the first refrigerant and propane (boiling point −40.09 ° C.) or carbon dioxide (boiling point −78.5 ° C.) as the second refrigerant. .

In the seventh and eighth embodiments, an internal heat exchanger that performs heat exchange between the first refrigerant that has flowed out of the first radiator 12 and the first refrigerant that has flowed out of the first evaporator 14 may be provided. Good. Thereby, the enthalpy of the 1st refrigerant | coolant before inflow into the 1st evaporator 14 can be reduced, and the cooling capacity of the 1st refrigerant | coolant which flows in into the 1st evaporator 14 can further be improved. Similarly, an internal heat exchanger that performs heat exchange between the second refrigerant that has flowed out of the second radiator 22 and the second refrigerant that has flowed out of the second evaporator 24 may be provided.

According to the present invention, it can be used in a refrigerator-freezer provided with first and second evaporators for cooling the refrigerator compartment and the freezer compartment, respectively. Moreover, it can utilize for the refrigerator provided with the 1st, 2nd evaporator which cools the 1st, 2nd cooling chamber from which temperature differs, respectively.

DESCRIPTION OF SYMBOLS 1 Refrigeration refrigerator 2 Refrigeration room 3 Vegetable room 4 Freezing room 10 1st freezing cycle 10a, 20a Refrigerant pipe 11 1st compressor 12 1st heat radiator 13, 43a 1st decompression device 14, 44a 1st evaporator 14a Cooling plate 15 Refrigerating room blower 16 1st dryer 17 1st receiver 20 2nd refrigeration cycle 21 2nd compressor 22 2nd radiator 23, 43b 2nd decompression device 24, 44b 2nd evaporator 25 freezer compartment blower 26 2nd dryer 27 2nd 2 receivers 30, 40 refrigeration cycle 31 intermediate heat exchanger 32 first internal heat exchanger 33 second internal heat exchanger 34 fourth internal heat exchanger 35 heat exchanger for defrosting 36 three-way valve 37 check valve 41 compressor 42 Radiator 50 Heat Insulating Material 51 Defrost Heater 61, 62 Temperature Sensor 63 Door Open / Close Detection Unit 64 Degree sensor 65 control unit 66 operation panel

Claims (47)

1. A cold storage room for storing stored items in a refrigerator, a freezing chamber for storing stored products in a frozen state, a first compressor that operates a first refrigeration cycle through which a first refrigerant flows, and a high temperature section of the first refrigeration cycle. A first radiator, a first evaporator disposed in a low temperature part of the first refrigeration cycle, a second compressor operating a second refrigeration cycle through which a second refrigerant flows, and a low temperature part of the second refrigeration cycle A second evaporator arranged, and an intermediate heat exchanger for exchanging heat between the low temperature part of the first refrigeration cycle and the high temperature part of the second refrigeration cycle, and cooling the refrigerator compartment by the first evaporator In addition, the freezer is cooled by the second evaporator.
2. The refrigerator-freezer according to claim 1, wherein the intermediate heat exchanger is arranged at a stage subsequent to the first evaporator.
3. 2. The refrigerator-freezer according to claim 1, further comprising a second radiator disposed in a high temperature part of the second refrigeration cycle.
4. 4. The refrigerator-freezer according to claim 3, wherein the intermediate heat exchanger is arranged at a stage subsequent to the second radiator.
5. 2. The refrigerator-freezer according to claim 1, wherein heat exchange is performed between the second refrigerant flowing out of the second evaporator and the first refrigerant before flowing into the first evaporator.
6. 2. The refrigerator-freezer according to claim 1, wherein heat exchange is performed between the second refrigerant flowing out of the second evaporator and the second refrigerant before flowing into the second evaporator.
7. A first internal heat exchanger that exchanges heat between the high-temperature first refrigerant in the first refrigeration cycle and the low-temperature second refrigerant in the second refrigeration cycle; and the low-temperature second refrigerant in the second refrigeration cycle and the low-temperature A second internal heat exchanger that exchanges heat with the second refrigerant, and a third internal heat exchanger that exchanges heat between the high-temperature first refrigerant and the low-temperature first refrigerant in the first refrigeration cycle; The refrigerator-freezer according to claim 1, wherein the refrigerator is provided.
8. 8. The refrigerator-freezer according to claim 7, wherein the third internal heat exchanger performs heat exchange between the first refrigerant flowing out from the first radiator and the first refrigerant flowing out from the intermediate heat exchanger. .
9. A second radiator disposed in the high temperature part of the second refrigeration cycle is provided in the front stage of the intermediate heat exchanger, and the second internal heat exchanger is formed from the second refrigerant and the second evaporator that have flowed out of the intermediate heat exchanger. The refrigerator-freezer according to claim 7, wherein heat exchange is performed with the second refrigerant that has flowed out.
10. The first internal heat exchanger performs heat exchange between the first refrigerant flowing out from the third internal heat exchanger and the second refrigerant flowing out from the second internal heat exchanger. Freezer refrigerator.
11. A first decompressor comprising a capillary tube and a first decompressor comprising a capillary tube disposed in a stage upstream of the first evaporator, wherein the first decompressor is a heat exchange pipe of the first internal heat exchanger or the third internal heat exchanger. The refrigerator-freezer according to claim 7, which functions as
12. A second decompressor comprising a capillary tube is provided in front of the second evaporator to decompress the second refrigerant, and the second decompressor functions as a heat exchange pipe for the second internal heat exchanger. The refrigerator-freezer according to claim 7.
13. 2. The refrigerator-freezer according to claim 1, further comprising a receiver that is disposed on a first refrigeration cycle side of the intermediate heat exchanger and that separates a gas-liquid of the first refrigerant and discharges a gas refrigerant.
14. The intermediate heat exchanger exchanges heat between the upstream side of the first refrigeration cycle and the downstream side of the second refrigeration cycle, and exchanges heat between the downstream side of the first refrigeration cycle and the upstream side of the second refrigeration cycle. The refrigerator-freezer according to claim 13.
15. The intermediate heat exchanger has a latent heat exchange section that mainly takes latent heat from the second refrigerant upstream of the receiver of the first refrigeration cycle and applies latent heat to the first refrigerant, and more than the receiver of the first refrigeration cycle. The refrigerator-freezer according to claim 14, further comprising a sensible heat exchange unit that draws sensible heat mainly from the second refrigerant downstream and applies sensible heat to the first refrigerant.
16. The refrigerator according to claim 1, wherein the first and second refrigerants are made of isobutane.
17. 2. The refrigerator-freezer according to claim 1, wherein the boiling point of the first refrigerant is higher than the boiling point of the second refrigerant.
18. The refrigerator-freezer according to claim 17, wherein the first refrigerant is made of isobutane and the second refrigerant is made of propane or carbon dioxide.
19. A main body having a refrigerator compartment for storing stored items in a refrigerator and a freezing chamber for storing stored items in a frozen state, a first compressor for operating a first refrigeration cycle through which a first refrigerant flows, and a first A first evaporator that is arranged in a low temperature part of the refrigeration cycle and cools the refrigerator compartment, a second compressor that operates a second refrigeration cycle through which the second refrigerant flows, and a low temperature part of the second refrigeration cycle. A second evaporator that cools the freezer compartment, a first machine chamber in which the first compressor is arranged, and a second machine chamber in which the second compressor is arranged, and the first and second machine chambers One of the above is disposed at the top of the main body, and the other is disposed at the bottom of the main body.
20. An intermediate heat exchanger is provided that exchanges heat between a first heat exchanging part disposed downstream of the first evaporator and a second heat exchanging part disposed in a high temperature part of the second refrigeration cycle. The refrigerator-freezer according to claim 19.
21. The refrigerator compartment and the freezer compartment are arranged in parallel up and down, and the first and second machine compartments are arranged in the vicinity of the refrigerator compartment and the freezer compartment, respectively, and the first behind the refrigerator compartment and the freezer compartment, respectively. An evaporator and a second evaporator are disposed, and the intermediate heat exchanger is disposed between the first compressor and the second compressor and extends vertically, and the first heat exchange unit and the second heat exchanger are disposed. 21. The refrigerator-freezer according to claim 20, wherein the heat exchange part is bent in the vertical direction, and the refrigerant inlet and the refrigerant outlet of the first and second heat exchange parts are provided in the vicinity of the first machine room.
22. A first radiator disposed in a high-temperature part of the first refrigeration cycle; a first decompressor disposed in a stage subsequent to the first radiator; and a first radiator disposed in a stage subsequent to the intermediate heat exchanger in the second refrigeration cycle. The first internal heat exchanger extending vertically and performing the heat exchange between the second decompressor, the second refrigerant flowing out of the second evaporator and the first decompressor, and the second refrigerant flowing out of the second evaporator And a second internal heat exchanger extending vertically to exchange heat between the first decompressor and the second decompressor, the refrigerant inflow side of the first decompressor is provided in the vicinity of the second compressor, and the second decompressor The refrigerator refrigerator according to claim 21, wherein the refrigerant inflow side is provided in the vicinity of the first compressor.
23. A first dryer for dehumidifying the first refrigerant before flowing into the first decompression device is disposed in the second machine chamber, and a second dryer for dehumidifying the second refrigerant before flowing into the second decompression device is provided in the first machine chamber. The refrigerator-freezer according to claim 22, wherein the refrigerator-freezer is disposed in the refrigerator.
24. The refrigerator according to claim 23, wherein the second dryer is covered with a heat insulating material.
25. The intermediate heat exchanger comprises a double pipe that covers an inner pipe with an outer pipe, a first refrigerant flows through the inner pipe to form a first heat exchange part, and a second refrigerant is a first refrigerant. The refrigerator-freezer according to claim 22, wherein the second heat exchange unit is formed by flowing in a direction opposite to the direction of the refrigerator.
26. The refrigerator-freezer according to claim 22, wherein a second radiator is provided between the second compressor and the intermediate heat exchanger.
27. 27. The refrigerator-freezer according to claim 26, wherein the first and second internal heat exchangers are embedded in the back wall of the heat insulation box, and the second radiator is disposed on the back surface of the main body.
28. 28. The refrigerator-freezer according to claim 27, wherein the intermediate heat exchanger is embedded in a back wall of the heat insulating box.
29. 21. The refrigerator-freezer according to claim 20, wherein the accumulator for separating the gas and liquid is installed on the refrigerant outflow side of the second evaporator and is not installed on the refrigerant outflow side of the first evaporator.
30. 20. The refrigerator-freezer according to claim 19, wherein a heat insulating wall partitioning the refrigerator compartment and the freezer compartment is provided with a heat insulating performance equivalent to a peripheral wall of the heat insulating box.
31. 20. The refrigerator-freezer according to claim 19, wherein a part of heat radiation of the first radiator is used for drain water treatment and prevention of dew condensation of the refrigerator-freezer.
32. It is arranged in a cold room for storing stored items in a refrigerator, a freezing chamber for storing stored items in a frozen state, a first compressor for operating a first refrigeration cycle through which a first refrigerant flows, and a low temperature part of the first refrigeration cycle. A first evaporator that cools the refrigerator compartment, a second compressor that operates a second refrigeration cycle through which a second refrigerant flows, and a second compressor that is disposed in a low temperature part of the second refrigeration cycle and cools the freezer compartment. A refrigerator-freezer comprising an evaporator, wherein the second evaporator is defrosted by heat of a high temperature part of the first refrigeration cycle.
33. A first radiator disposed in the high temperature portion of the first refrigeration cycle, a three-way valve provided on the refrigerant inflow side of the first radiator, and the branching by the three-way valve are disposed in parallel with the first radiator. A defrosting heat exchanger for exchanging heat with the second evaporator, and a check valve provided on the refrigerant outflow side of the defrosting heat exchanger, wherein the three-way valve is disposed when defrosting the second evaporator The refrigerator-freezer according to claim 32, wherein the refrigerator is switched to the defrosting heat exchanger side.
34. 34. The refrigerator-freezer according to claim 33, wherein the check valve is disposed in the vicinity of a junction between the refrigerant outlet side of the first radiator and the refrigerant outlet side of the defrosting heat exchanger.
35. The second evaporator and the defrosting heat exchanger have first and second refrigerant pipes through which the first and second refrigerants circulate, respectively, and the first and second refrigerant pipes are connected by a plurality of fins. The refrigerator-freezer according to claim 32, wherein the refrigerator is freezer.
36. The second evaporator and the heat exchanger for defrosting have first and second refrigerant tubes through which the first and second refrigerants circulate, respectively, and the first and second refrigerant tubes are adjacent to each other. Item 33. The refrigerator-freezer according to Item 32.
37. 33. The refrigerator-freezer according to claim 32, wherein the cross-sectional area of the refrigerant pipe of the heat exchanger for defrosting is ½ or less of the cross-sectional area of the refrigerant pipe of the first evaporator.
38. 33. The refrigerator-freezer according to claim 32, wherein the first compressor is stopped for a predetermined period before defrosting the second evaporator.
39. It is arranged in a cold room for storing stored items in a refrigerator, a freezing chamber for storing stored items in a frozen state, a first compressor for operating a first refrigeration cycle through which a first refrigerant flows, and a low temperature part of the first refrigeration cycle. A first evaporator that cools the refrigerator compartment, a second compressor that operates a second refrigeration cycle through which a second refrigerant flows, and a second compressor that is disposed in a low temperature part of the second refrigeration cycle and cools the freezer compartment. An refrigerator, wherein the first evaporator is formed by fixing a metal cooling plate covering a wall surface of the refrigerator compartment to a refrigerant pipe, and the refrigerator compartment is radiatively cooled by the cooling plate. .
40. A door opening / closing detector for detecting opening / closing of the door of the refrigerator compartment, a temperature sensor for detecting the temperature of the refrigerator compartment, and a humidity sensor for detecting the humidity of the refrigerator compartment, when the door is opened and closed 40. The dew point temperature of the refrigerator compartment is acquired by detection of the temperature sensor and the humidity sensor, and the first refrigeration cycle is operated so that the first evaporator is equal to or lower than the dew point temperature. The refrigerator-freezer as described.
41. 40. The refrigerator-freezer according to claim 39, further comprising an intermediate heat exchanger that performs heat exchange between the low temperature part of the first refrigeration cycle and the high temperature part of the second refrigeration cycle.
42. 40. The refrigerator-freezer according to claim 39, wherein an isolation room having a temperature lower than that of the upper part is provided at a lower part of the refrigerating room, and the refrigerant flows through the refrigerant pipe of the first evaporator from below to above.
43. The first and second cooling chambers, the first compressor that operates the first refrigeration cycle through which the first refrigerant flows, the first radiator disposed in the high temperature portion of the first refrigeration cycle, and the first refrigeration cycle A first evaporator disposed in the low temperature section, a second compressor operating a second refrigeration cycle through which the second refrigerant flows, a second evaporator disposed in the low temperature section of the second refrigeration cycle, An intermediate heat exchanger for exchanging heat between the low temperature part of the refrigeration cycle and the high temperature part of the second refrigeration cycle, cooling the first cooling chamber by the first evaporator and secondly by the second evaporator. A refrigerator that cools a cooling chamber.
44. A first internal heat exchanger that exchanges heat between the high-temperature first refrigerant of the first refrigeration cycle and the low-temperature first refrigerant of the second refrigeration cycle; A second internal heat exchanger that exchanges heat with the second refrigerant, a third internal heat exchanger that exchanges heat between the high-temperature first refrigerant and the low-temperature first refrigerant in the first refrigeration cycle, 44. The refrigerator according to claim 43, wherein:
45. 45. The refrigerator according to claim 43, further comprising: a receiver that is disposed on the first refrigeration cycle side of the intermediate heat exchanger and that separates the gas and liquid of the first refrigerant and discharges the gas refrigerant.
46. A main body having first and second cooling chambers, a first compressor that operates a first refrigeration cycle through which a first refrigerant flows, and a low temperature portion of the first refrigeration cycle are provided to cool the first cooling chamber. A first evaporator, a second compressor that operates a second refrigeration cycle through which a second refrigerant flows, a second evaporator that is disposed in a low temperature part of the second refrigeration cycle and cools the second cooling chamber, A first machine room in which one compressor is arranged and a second machine room in which a second compressor is arranged, and one of the first and second machine rooms is arranged on the upper part of the main body, and the other Is disposed in the lower part of the main body.
47. First and second cooling chambers, a first compressor that operates a first refrigeration cycle through which a first refrigerant flows, and a first evaporator that is disposed in a low temperature portion of the first refrigeration cycle and cools the first cooling chamber And a second compressor that operates the second refrigeration cycle through which the second refrigerant circulates, and a second evaporator that is disposed in a low temperature portion of the second refrigeration cycle and cools the first cooling chamber, The refrigerator which defrosts a 2nd evaporator with the heat of the high temperature part of a cycle.

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