WO2019038797A1

WO2019038797A1 - Air conditioning device and expansion valve unit

Info

Publication number: WO2019038797A1
Application number: PCT/JP2017/029737
Authority: WO
Inventors: 侑哉森下
Original assignee: 三菱電機株式会社
Priority date: 2017-08-21
Filing date: 2017-08-21
Publication date: 2019-02-28
Also published as: JPWO2019038797A1; DE112017007962T5

Abstract

This air conditioning device comprises: a refrigerant circuit in which refrigerant circulates and in which a heat source-side unit that has a compressor and a heat source-side heat exchanger, an expansion valve unit that has an expansion valve, and a load-side unit that has a load-side heat exchanger and that air conditions a given space are connected with piping; and a refrigerant leak detection device that detects refrigerant leaks; wherein the expansion valve unit is outside of the space being air conditioned and is provided in piping in which flows refrigerant condensed by the heat source-side heat exchanger functioning as a condenser and flowing from the heat source-side unit, and the expansion valve assumes a closed state after the refrigerant leak detection device has detected a refrigerant leak.

Description

Air conditioner and expansion valve unit

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an air conditioner and an expansion valve unit that suppress the leakage of refrigerant into an air-conditioned space.

BACKGROUND ART Conventionally, an air conditioner that can suppress the leakage of a refrigerant is known. For example, in Patent Document 1, the outdoor unit is provided with an emergency refrigerant shutoff valve and an emergency refrigerant discharge valve, and when the refrigerant leaks in the air-conditioned space, the emergency refrigerant shutoff valve is closed to The amount of refrigerant leaking to the air-conditioned space is suppressed by discharging the

Japanese Patent Application Laid-Open No. 2002-115939

However, in Patent Document 1, since the emergency refrigerant shutoff valve is provided in the outdoor unit, the refrigerant present inside the pipe downstream of the emergency refrigerant shutoff valve after the emergency refrigerant shutoff valve is closed, It may continue to leak into the air-conditioned space.

This invention is made in view of the above subjects, and it aims at obtaining the air harmony device and expansion valve unit which can control the leak of the refrigerant to air-conditioning space.

An air conditioner according to the present invention includes a heat source side unit having a compressor and a heat source side heat exchanger, an expansion valve unit having an expansion valve, and a load side having a load side heat exchanger for performing air conditioning of a conditioned space. The unit includes a refrigerant circuit connected by piping and circulating a refrigerant, and a refrigerant leakage detection device that detects leakage of the refrigerant, and the expansion valve unit functions as a condenser outside the air conditioning space It is disposed in a pipe through which the refrigerant condensed in the heat source side heat exchanger and flowing out from the heat source side unit flows, and the expansion valve is closed after the refrigerant leakage detection device detects the refrigerant leakage. .

According to the air conditioner pertaining to the present invention, the expansion valve unit that shuts off the flow of the refrigerant when the refrigerant leaks is condensed by the heat source side heat exchanger that is external to the air conditioning space and that functions as a condenser. Since the refrigerant flowing out of the heat source side unit is disposed in the piping through which the refrigerant flows, and the distance between the portion for shutting off the refrigerant and the load side unit is close, leakage of the refrigerant to the air conditioned space can be suppressed. .

It is a figure which shows an example of installation of the air conditioning apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows an example of a structure of the air conditioning apparatus of FIG. It is a figure which shows an example of a structure of the expansion valve unit of FIG. 1 and FIG. FIG. 7 is a diagram showing an example of the operation of the air conditioning apparatus according to Embodiment 1. It is a figure which shows the modification 1 which is a modification of FIG. It is a figure which shows the modification 2 which is a modification of FIG. It is a figure which shows an example of a structure of the expansion valve unit of the air conditioning apparatus which concerns on Embodiment 2 of this invention.

Hereinafter, an embodiment of the present invention will be described based on the drawings. Here, in the following drawings, the relationship of the size of each component may differ from an actual thing. In addition, when there is no need to distinguish or specify a plurality of similar devices distinguished by subscripts, etc., the subscripts may be omitted. In addition, regarding the temperature and pressure levels described below, the level is not determined in relation to the absolute values, but is expressed based on the relative relationship in the state, operation, etc. of the device etc. It shall be done.

Embodiment 1
[Air conditioner]
FIG. 1 is a view showing an example of the installation of the air conditioning apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a view showing an example of the configuration of the air conditioning apparatus shown in FIG. These are figures which show an example of a structure of the expansion valve unit of FIG. 1 and FIG. In addition, in FIG. 3, in order to facilitate understanding of this embodiment, the heat source side unit 20 and the load side unit 80 are simplified and described in comparison with FIGS. 1 and 2.

The air conditioning apparatus 100 described in FIG. 1 and FIG. 2 performs air conditioning using a refrigeration cycle. The air conditioner 100 has a refrigerant circuit 101 in which a refrigerant circulates. The refrigerant circuit 101 is formed by connecting the heat source unit 20, the expansion valve unit 60, and the load unit 80 by piping. The air conditioning apparatus 100 according to this embodiment is, for example, a multi-air conditioner for buildings in which a heat source side unit 20 is provided on the outdoor 2 outside the building and a plurality of load side units 80 are provided in the air conditioning space 6 inside the building. Applies to The air conditioning apparatus 100 performs a cooling operation for cooling the air conditioning space 6 inside the room by switching the flow direction of the refrigerant circulating to the refrigerant circuit 101 or a heating operation for heating the air conditioning space 6 inside the room Can be performed. The refrigerant applied to the air conditioning apparatus 100 of the example of this embodiment is, for example, a refrigerant having a slight flame retardance such as HFO 1234yf, R32, HC (hydrocarbon), etc., but the type of the refrigerant is not particularly limited. That is, the refrigerant applied to the air conditioner 100 of the example of this embodiment is a mixed refrigerant containing HFO1234yf, HFO1234ze, R32, R32 and HFO1234yf, a mixed refrigerant containing the above-described refrigerant in at least one component, It is also good. Further, the refrigerant applied to the air conditioning apparatus 100 of the example of this embodiment may be, for example, a natural refrigerant such as carbon dioxide. HFO 1234yf, R32, HC, carbon dioxide, etc., which have a small global warming potential, meet the recent demand for global warming suppression. Since the air conditioning apparatus 100 performs heat exchange between the refrigerant and the air in the load side unit 80 to perform air conditioning of the air-conditioned space 6 such as an office space, a living room, or a store, it is necessary to take measures against refrigerant leakage. There is sex. In an air conditioning apparatus 100 such as a building multi air conditioner where the heat source side unit 20 and the plurality of load side units 80 are connected, the pipe connecting the heat source side unit 20 and the load side unit 80 may be 100 m, for example. Because a large amount of refrigerant is charged into the refrigerant circuit 101, the necessity for taking measures against refrigerant leakage is particularly high.

The air conditioning apparatus 100 of the example of this embodiment has one heat source side unit 20, a plurality of expansion valve units 60, and a plurality of load side units 80. The heat source side unit 20 and the load side unit 80 are connected via the relay device 40. The heat source side unit 20 and the relay device 40 are connected by the main pipe 102, and the relay device 40 and the load side unit 80 are connected by the branch pipe 104. In the example shown in FIGS. 1 and 2, the heat source side unit 20 and the relay device 40 are connected using two main pipes 102, and each of the relay device 40 and the load side unit 80 is two. It is connected using a branch pipe 104. The expansion valve unit 60 is disposed in the branch pipe 104. Cold heat or heat generated by the heat source side unit 20 is delivered to the load side unit 80. In addition, although the example of this embodiment demonstrates the air conditioning apparatus 100 which has one heat source side unit 20, two expansion valve units 60, and two load side units 80, the air conditioning apparatus 100 , One heat source side unit 20, one expansion valve unit 60, and one load side unit 80, or one heat source side unit 20 and three or more expansion valve units 60. And three or more load side units 80 may be included.

[Heat source side unit]
The heat source unit 20 supplies cold or heat to the load unit 80. The heat source side unit 20 is usually installed at the outdoor 2 outside (for example, the rooftop etc.) outside the building 8 such as a building. The heat source side unit 20 includes the compressor 22, the flow path switching device 24, the heat source side heat exchanger 26, the backflow prevention device 28, the accumulator 30, the heat exchange promoting device 27, the heat source side power reception unit 34 and the heat source side unit control device 36. And a discharge pressure sensor 33a and a suction pressure sensor 33b. The discharge pressure sensor 33 a is provided on the discharge side of the compressor 22 and detects the pressure of the refrigerant discharged from the compressor 22. The suction pressure sensor 33 b is provided on the suction side of the compressor 22 and detects the pressure of the refrigerant drawn into the compressor 22. The heat source side unit power receiving unit 34 receives power from the heat source side unit power supply 32 and supplies power to the heat source side unit 20. The heat source side unit controller 36 controls the heat source side unit 20. The heat source side unit controller 36 is formed to include, for example, an analog circuit, a digital circuit, or a processor. The compressor 22, the flow path switching device 24, the heat source side heat exchanger 26, the backflow prevention device 28 and the accumulator 30 are connected by piping and mounted on the heat source side unit 20.

The compressor 22 sucks the refrigerant and compresses the sucked refrigerant to a high temperature and high pressure state. The compressor 22 may be configured by, for example, an inverter compressor or the like whose capacity can be controlled. The flow path switching device 24 is formed of, for example, a four-way valve, and switches the flow direction of the refrigerant in the cooling operation mode and the flow direction of the refrigerant in the heating operation mode. In the example of FIG. 2, the flow path switching device 24 is switched to the solid line state in the cooling operation mode, and the flow path switching device 24 is switched to the broken line state in the heating operation mode.

The heat source side heat exchanger 26 exchanges heat with the air. The heat source side heat exchanger 26 may exchange heat with the heat medium such as water or brine. The heat source side heat exchanger 26 functions as an evaporator that evaporates the refrigerant during heating operation, and functions as a condenser that condenses the refrigerant during cooling operation. The heat exchange promoting device 27 promotes heat exchange in the heat source side heat exchanger 26. The heat source side heat exchanger 26 in the example of this embodiment is an air heat exchanger that exchanges heat with refrigerant air, and the heat exchange promoting device 27 is a fan such as a fan that blows air to the heat source side heat exchanger 26. Is formed. When the heat source side heat exchanger 26 is a refrigerant-heat medium heat exchanger that exchanges heat with a heat medium such as water or brine, the heat exchange promoting device 27 adjusts the transport amount of the heat medium. It is formed including a pump and the like.

The backflow prevention device 28 prevents backflow of the refrigerant. The backflow prevention device 28 is formed of, for example, an open / close valve, a shutoff valve or the like. The backflow prevention device 28 is disposed between the load side unit 80 functioning as an evaporator and the compressor 22, and the refrigerant evaporated by the load side unit 80 functioning as an evaporator is drawn into the compressor 22. Allow only the flow of That is, when the backflow prevention device 28 is formed by the on-off valve, the shutoff valve, etc., the backflow prevention device 28 formed by the on-off valve, the shutoff valve, etc. is closed when there is a possibility that the refrigerant flows backward. . The backflow prevention device 28 may be any device that allows only the flow of the refrigerant in a certain direction, and may be, for example, a check valve. The accumulator 30 is provided on the suction side of the compressor 22, and surplus refrigerant due to the difference between the heating operation mode and the cooling operation mode, and changes in transient operation (for example, changes in the number of the load side units 80 operated) ) For the surplus refrigerant. For example, the accumulator 30 is disposed between the suction side of the compressor 22 and the backflow prevention device 28. Since the backflow prevention device 28 prevents the backflow of the refrigerant, the possibility of the refrigerant stored in the accumulator 30 flowing out to the outside of the heat source side unit 20 is suppressed.

[Relaying device]
The relay device 40 branches or joins refrigerants, and relays the heat source side unit 20 and a plurality of load side units 80. The relay device 40 is in the space such as the ceiling and the like which is the space inside the building 8 but different from the air-conditioned space 6 (for example, the space such as the ceiling and the like in the building 8, hereinafter simply referred to as the non-air-conditioned space 4) is set up. The relay device 40 can also be installed in a common space where there is an elevator or the like, or outside the building 8 or the like.

[Load side unit]
The load side unit 80 performs air conditioning of the air-conditioned space 6 by supplying the cooling air or the heating air to the air-conditioned space 6 (including the air path and the like leading to the room). The load side unit 80 is disposed at a position where the cooling air or the heating air can be supplied to an air-conditioned space 6 (for example, a living room etc.) which is a space inside the building 8. In addition, although the load side unit 80 is a ceiling cassette type, for example, it is not limited to this. The load side unit 80 may be any unit capable of blowing out the heating air or the cooling air directly or by a duct or the like into the air-conditioned space 6, and is, for example, a ceiling-embedded type or a ceiling-suspended type. May be The load side unit 80 includes a load side heat exchanger 82, a blower 83, a load side unit power receiving unit 90, a load side unit controller 92, a first temperature sensor 66, and a second temperature sensor 68.

The load side heat exchanger 82 exchanges heat with the air. The air heat-exchanged by the load-side heat exchanger 82 is supplied to the air-conditioned space 6 as heating air or cooling air. The blower 83 is a fan or the like for blowing air to the load side heat exchanger 82. The load-side unit power receiving unit 90 receives power from the load-side unit power supply 88 and supplies power to the load-side unit 80. The load side unit controller 92 controls the load side unit 80. The load side unit controller 92 is formed to include, for example, an analog circuit, a digital circuit, or a processor.

The first temperature sensor 66 detects the temperature of the liquid refrigerant that flows into the load side heat exchanger 82 or flows out of the load side heat exchanger 82. The first temperature sensor 66 is attached to, for example, a pipe through which the liquid refrigerant flows. The second temperature sensor 68 detects the temperature of the gas refrigerant that flows into the load side heat exchanger 82 or flows out of the load side heat exchanger 82. The second temperature sensor 68 is attached to, for example, a pipe through which a gas refrigerant flows. The first temperature sensor 66 and the second temperature sensor 68 may be configured by a thermistor or the like. By having the first temperature sensor 66 and the second temperature sensor 68, it is possible to detect the temperature of the refrigerant flowing into the load side heat exchanger 82 and the temperature of the refrigerant flowing out from the load side heat exchanger 82. it can.

[Expansion valve unit]
As shown in FIG. 3, the expansion valve unit 60 has an expansion valve 64 capable of adjusting the opening degree. The expansion valve unit 60 adjusts the pressure and amount of the refrigerant passing through the expansion valve unit 60 during the cooling operation or the heating operation. Further, the expansion valve unit 60 has a function of blocking the flow of the refrigerant by closing the flow path when the refrigerant leaks. The expansion valve unit 60 is disposed outside the air conditioning space 6 and in a pipe through which the refrigerant which is condensed by the heat source side heat exchanger 26 functioning as a condenser and flows out from the heat source side unit 20 flows. When the refrigerant leaks, expansion valve unit 60 shuts off the flow of the refrigerant, whereby the refrigerant can be suppressed from leaking from refrigerant circuit 101 downstream of expansion valve unit 60 to air conditioning space 6. Furthermore, when the expansion valve unit 60 shuts off the flow of refrigerant, the refrigerant downstream of the expansion valve unit 60 is stored in the pipe upstream of the expansion valve unit 60 and the heat source side heat exchanger 26 functioning as a condenser. . Moreover, in the example of this embodiment, the expansion valve unit 60 is the outside of the air conditioning space 6 and is condensed by the heat source side heat exchanger 26 functioning as a condenser, and the refrigerant which has flowed out of the heat source side unit 20 is Since it is arrange | positioned by flowing piping and the distance of the location which interrupts | blocks a refrigerant | coolant and the load side unit 80 is closely approached, the leakage of the refrigerant | coolant to the air-conditioning space 6 can be suppressed. Furthermore, since the distance between the portion blocking the refrigerant and the load side unit 80 is close, the refrigerant recovery operation for storing the refrigerant downstream of the expansion valve unit 60 upstream of the expansion valve unit 60 is completed in a short time. Can. Moreover, in the example of this embodiment, the expansion valve unit 60 is the outside of the air conditioning space 6 and is condensed by the heat source side heat exchanger 26 functioning as a condenser, and the refrigerant which has flowed out of the heat source side unit 20 is It is arrange | positioned by each of the branch pipe 104 among the flowing piping. Since the expansion valve unit 60 is disposed in each of the branch pipes 104, the amount of refrigerant flowing to the load-side heat exchanger 82 provided in each of the branch pipes 104 can be adjusted. Furthermore, since the expansion valve unit 60 is disposed in each of the branch pipes 104, the refrigerant can be stored in the branch pipe 104 upstream of the expansion valve unit 60 when the refrigerant leaks. Furthermore, since the expansion valve unit 60 is provided in the branch pipe 104 whose pipe diameter is smaller than that of the main pipe 102, the cost of the opening / closing device 62 and the expansion valve 64 can be reduced. The expansion valve unit 60 may be provided outside the heat source side unit 20 and outside the air conditioning space 6, but the expansion valve unit 60 is, as shown in FIG. It is good to be provided in the non-air-conditioned space 4 which is outside the air-conditioned space 6. By providing the expansion valve unit 60 close to the load side unit 80, leakage of the refrigerant can be suppressed, and the expansion valve unit 60 is provided in an environment not exposed to wind and rain like the non-air conditioned space 4 The reliability of the expansion valve unit 60 is improved and maintenance and the like are facilitated.

As shown in FIG. 3, the expansion valve unit 60 includes an opening / closing device 62, an expansion valve 64, an expansion valve unit power receiving unit 72, and an expansion valve unit control device 74. The expansion valve unit power receiving unit 72 receives power from the expansion valve unit power supply 70 and supplies power to the expansion valve unit 60. In the example of this embodiment, the heat source side unit 20 receives electric power from the heat source side unit power supply 32, and the expansion valve unit 60 receives electric power from the expansion valve unit power supply 70. Power is received from the load-side unit power supply 88. The load-side unit 80 receives power from the load-side unit power supply 88, which is a power supply different from the power supply received by the heat source unit 20 and the expansion valve unit 60, causing an abnormality or the like in the air conditioning apparatus 100. Sometimes, only the load side unit 80 can be de-energized. When abnormality or the like occurs in the air conditioning apparatus 100, the safety of the air conditioning space 6 is ensured by deenergizing only the load side unit 80, and the heat source side unit 20 or the expansion valve unit 60 operates with the energized state. It can be done. In addition, the air conditioning apparatus 100 of the example of this embodiment should be able to operate only the load side unit 80 in the non-energized state and operate the heat source unit 20 or the expansion valve unit 60 in the energized state. For example, the expansion valve unit 60 can be configured to receive power from the heat source side unit power supply 32, or can be configured to receive power from the heat source side unit power receiving unit 34 of the heat source side unit 20. The expansion valve unit controller 74 controls the expansion valve unit 60. The expansion valve unit controller 74 is formed to include, for example, an analog circuit, a digital circuit, or a processor.

The opening and closing device 62 switches between communication and interruption of the flow path by opening and closing operation. The opening and closing device 62 is formed of, for example, an opening and closing valve, a shutoff valve, and the like. The open / close device 62 may be formed to be in a closed state when not energized. The expansion valve 64 decompresses and expands the refrigerant. The expansion valve 64 is formed of one whose opening degree can be variably controlled, such as an electronic expansion valve. The opening / closing device 62 and the expansion valve 64 are connected in series by piping and mounted on the expansion valve unit 60. The opening / closing device 62 and the expansion valve 64 are provided on the upstream side of the load side heat exchanger 82 when the load side heat exchanger 82 functions as an evaporator. For example, the expansion valve 64 is disposed downstream of the opening / closing device 62 when the heat source side heat exchanger 26 functions as a condenser, and the influence of pressure loss is reduced. Furthermore, the expansion valve 64 is provided downstream of the switching device 62 when the heat source side heat exchanger 26 functions as a condenser, so that the expansion valve 64 is opened based on the pressure loss when the switching device 62 is in the open state. It becomes possible to adjust the degree, and the followability of the control of the opening degree of the expansion valve 64 is improved. The expansion valve 64 may be formed of a capillary tube or the like whose opening degree can not be adjusted. When the expansion valve 64 is formed of a capillary tube or the like whose opening degree can not be adjusted, although the opening / closing device 62 can not be omitted, the expansion valve 64 is formed of an electronic expansion valve etc. capable of adjusting the opening degree. At this time, the opening and closing device 62 can be omitted. With the configuration having the opening / closing device 62 and the expansion valve 64 capable of adjusting the opening degree, the function of the flow of the refrigerant of the expansion valve unit 60 when the refrigerant leaks can be reliably realized. The opening and closing device 62 may be formed by an opening and closing valve or the like. However, by forming the opening and closing device 62 by a shutoff valve, it is possible to reliably shut off the refrigerant.

Moreover, the air conditioning apparatus 100 of the example of this embodiment has the refrigerant | coolant leak detection apparatus 120 and the alerting apparatus 130, as shown in FIG. 1 or FIG. The refrigerant leakage detection device 120 shown in FIG. 2 detects the refrigerant that has leaked from the refrigerant circuit 101. The refrigerant leak detection device 120 is connected to the heat source side unit controller 36, the expansion valve unit controller 74, or the load side unit controller 92, and when the refrigerant leak detection device 120 detects a refrigerant leak, the air conditioner 100 performs operation corresponding to the leakage of the refrigerant. The refrigerant leak detection device 120 is formed to include, for example, a sensor that detects the concentration of the refrigerant in the air as an electrical resistance value. The refrigerant leak detection device 120 includes an indoor sensor 120A disposed inside the air conditioning space 6 for detecting the leakage of the refrigerant, and an outdoor sensor 120B disposed outside the air conditioning space 6 for detecting the leakage of the refrigerant. ing. The outdoor sensor 120 </ b> B may be provided, for example, in the vicinity of the relay device 40 in which refrigerant leakage is likely to occur. The notification device 130 illustrated in FIG. 1 performs notification by sound or light, or a combination of sound and light. The notification device 130 is provided, for example, at a location with high visibility such as a ceiling or a wall of the air-conditioned space 6. For example, as shown in FIG. 3, the notification device 130 is connected to the expansion valve unit 60 having a power supply system different from that of the load side unit 80, and can continue the notification even after the load side unit 80 is stopped. It is supposed to be.

In the above, the heat source side unit controller 36, the expansion valve unit controller 74 and the load side unit controller 92 are provided, and the heat source side unit controller 36, the expansion valve unit controller 74 and the load side unit controller 92. Although an example in which the control of the entire air conditioning apparatus 100 is performed has been described, the air conditioning apparatus 100 according to this embodiment is the heat source unit control apparatus 36, the expansion valve unit control apparatus 74, or the load side. It may be one having one or more of the unit control devices 92. That is, the control device that controls the air conditioner 100 according to this embodiment is one of the heat source unit control device 36, the expansion valve unit control device 74, or the load side unit control device 92 or the control described above. It may be any two of the devices.

[Operation mode of air conditioner]
Next, an operation mode performed by the air conditioning apparatus 100 will be described. The air conditioning apparatus 100 of the example of this embodiment can perform only the cooling operation or can perform only the heating operation. That is, in the air conditioning apparatus 100, the cooling operation mode in which all of the driving load side units 80 can execute the cooling operation and the heating operation of all the driving load side units 80 can be performed. And a heating operation mode that can be performed.

[Cooling operation mode]
In the cooling operation mode, the flow path switching device 24 shown in FIG. 2 is switched to the state of the solid line. The compressor 22 sucks and compresses a low temperature / low pressure refrigerant, and discharges a high temperature / high pressure gas refrigerant. The high temperature / high pressure gas refrigerant discharged from the compressor 22 passes through the flow path switching device 24 and flows into the heat source side heat exchanger 26 functioning as a condenser. The refrigerant that has flowed into the heat source side heat exchanger 26 condenses while being released to the outdoor air by the heat source side heat exchanger 26, and becomes a high-pressure liquid refrigerant. The high pressure liquid refrigerant flowing out of the heat source side heat exchanger 26 flows out of the heat source side unit 20, passes through the main pipe 102, and is branched by the relay device 40. The refrigerant branched by the relay device 40 passes through the branch pipe 104 and flows into the expansion valve unit 60 provided in the branch pipe 104. The refrigerant flowing into the expansion valve unit 60 is expanded by the expansion valve 64 and becomes a low temperature / low pressure two-phase refrigerant. The two-phase refrigerant expanded by the expansion valve 64 flows into the load side unit 80 through the branch pipe 104. The refrigerant flowing into the load side unit 80 flows into the load side heat exchanger 82 functioning as an evaporator, absorbs heat from the room air, evaporates while cooling the room air, and cools and low-pressure gas refrigerant Become. The gas refrigerant flowing out of the load-side heat exchanger 82 flows out of the load-side unit 80, passes through the branch pipe 104, and joins at the relay device 40. The refrigerant merged by the relay device 40 flows into the heat source side unit 20 through the main pipe 102. The refrigerant that has flowed into the heat source side unit 20 passes through the flow path switching device 24, the backflow prevention device 28, and the accumulator 30 and is again drawn into the compressor 22. When the expansion valve 64 is in the cooling operation mode, the superheat (degree of superheat) obtained as the difference between the temperature detected by the first temperature sensor 66 and the temperature detected by the second temperature sensor 68 is constant. So that the opening degree is controlled.

In the cooling operation mode, when there is no cooling load, it is not necessary to flow the refrigerant to the load-side heat exchanger 82. For example, the switching device 62 or the expansion valve connected to the load-side heat exchanger 82 having no cooling load. 64 is closed. Then, when a cold load is generated, the opening / closing device 62 and the expansion valve 64 are opened to circulate the refrigerant, and the refrigerant flows to the load side heat exchanger 82.

[Heating mode]
In the heating operation mode, the flow path switching device 24 is switched to the state of the broken line. The compressor 22 sucks and compresses a low temperature / low pressure refrigerant, and discharges a high temperature / high pressure gas refrigerant. The high temperature / high pressure gas refrigerant discharged from the compressor 22 passes through the flow path switching device 24 and flows out from the heat source side unit 20. The refrigerant flowing out of the heat source side unit 20 is branched by the relay device 40 through the main pipe 102. The refrigerant branched by the relay device 40 flows into the load side unit 80 through the branch pipe 104. The refrigerant that has flowed into the load unit 80 flows into the load heat exchanger 82 that functions as a condenser, dissipates heat into the room air, and condenses while warming the room air to become a high-pressure liquid refrigerant. The liquid refrigerant flowing out of the load-side heat exchanger 82 flows out of the load-side unit 80, passes through the branch pipe 104, and flows into the expansion valve unit 60 provided in the branch pipe 104. The refrigerant flowing into the expansion valve unit 60 is expanded by the expansion valve 64 and becomes a low temperature / low pressure two-phase refrigerant. The two-phase refrigerant expanded by the expansion valve 64 merges in the relay device 40 through the branch pipe 104 and flows into the heat source side unit 20 again through the main pipe 102. The refrigerant flowing into the heat source side unit 20 flows into the heat source side heat exchanger 26 functioning as an evaporator, evaporates while absorbing heat from the outdoor air, and becomes a low temperature low pressure gas refrigerant. The refrigerant that has flowed out of the heat source side heat exchanger 26 is again drawn into the compressor 22 through the flow path switching device 24, the backflow prevention device 28 and the accumulator 30. In the heating operation mode, the expansion valve 64 is a subcool obtained as a difference between a value obtained by converting the pressure detected by the discharge pressure sensor 33 a into a saturated temperature and the temperature detected by the first temperature sensor 66 ( The opening degree is controlled such that the degree of supercooling is constant.

In the heating operation mode, when there is no thermal load, it is not necessary to flow the refrigerant to the load-side heat exchanger 82. For example, the switching device 62 or the expansion valve connected to the load-side heat exchanger 82 having no thermal load. 64 is closed. When the thermal load is generated, the switching device 62 and the expansion valve 64 are opened to flow the refrigerant to the load-side heat exchanger 82.

[Operation of air conditioner]
FIG. 4 is a diagram showing an example of the operation of the air conditioning apparatus of the first embodiment. In step S02, the air conditioning apparatus 100 performs the normal operation in the cooling operation mode or the heating operation mode. In step S04, when the concentration of the refrigerant detected by the refrigerant leak detection device 120 is lower than the preset concentration and the refrigerant does not leak, the normal operation of the air conditioner 100 is continued. When the concentration of the refrigerant detected by the refrigerant leakage detection device 120 is equal to or higher than the preset concentration set in step S04 and there is a possibility that the refrigerant is leaking, the process proceeds to step S06. The preset concentration set in advance is set for each type of refrigerant. For example, in the case of a slightly flammable refrigerant such as HFO 1234yf, R32, HC, etc., the set concentration is set to 1/10 or less of the lower limit value of the concentration which may be burned. Also, for example, in the case of carbon dioxide, the set concentration is set to 1/10 or less of the concentration that requires ventilation.

In step S06, the air conditioning apparatus 100 notifies that the refrigerant is leaking when the concentration of the refrigerant reaches or exceeds the preset concentration. The notification in step S06 is performed by the notification device 130. The notification in step S06 may be performed by display on a liquid crystal monitor such as a controller (not shown). The notification in step S06 may be changed according to the concentration of the refrigerant, and may include a display indicating a portion where the refrigerant is leaking.

At step S08, load side unit 80 is stopped. For example, when the electrical connection between the load-side unit power receiving unit 90 and the load-side unit power supply 88 is disconnected, the load-side unit 80 is stopped. By stopping the operation of the load unit 80 when the refrigerant leaks, the safety of the air-conditioned space 6 is improved. In the air conditioner 100 of the example of this embodiment, when the refrigerant leaks, only the operation of the blower 83 of the load side unit 80 may be stopped in step S08, but the load may be reduced. By disconnecting the electrical connection between the side unit power receiving unit 90 and the load unit power supply 88, the safety of the air conditioning space 6 is further improved.

In step S10, the air conditioning apparatus 100 executes a refrigerant recovery operation for recovering the refrigerant. When the air conditioning apparatus 100 executes the refrigerant recovery operation, the flow path switching device 24 is switched so that the heat source side heat exchanger 26 functions as a condenser, and the opening / closing device 62 and the expansion valve 64 are closed. That is, when the air conditioning apparatus 100 executes the refrigerant recovery operation, the flow path switching device 24 shown in FIG. 2 is switched to the solid line state, and the refrigerant flow direction is the same as in the cooling operation mode. In this state, the open / close device 62 and the expansion valve 64 are closed.

The refrigerant compressed by the compressor 22 flows into the heat source side heat exchanger 14 via the flow path switching device 24. The refrigerant flowing into the heat source side heat exchanger 14 is heat-exchanged in the heat source side heat exchanger 14 and condensed. The refrigerant condensed by the heat source side heat exchanger 14 is stored in the pipe upstream of the opening and closing device 62 and the heat source side heat exchanger 14 because the opening and closing device 62 and the expansion valve 64 are closed. In the air conditioner 100 of the example of this embodiment, when the refrigerant leaks, the refrigerant is shut off by the expansion valve unit 60 having the opening / closing device 62 and the expansion valve 64, and the load side unit 80 downstream of the expansion valve unit 60. The refrigerant does not flow into the Then, the refrigerant downstream of the expansion valve unit 60 is drawn into the compressor 22 and stored upstream of the expansion valve unit 60. In the air conditioner 100 of the example of this embodiment, when there is a risk of leakage of the refrigerant, the refrigerant present on the suction side of the compressor 22 from the downstream of the expansion valve unit 60 is the discharge side of the compressor 22 Since the valve is stored upstream of the expansion valve unit 60, the risk of refrigerant leakage in the air-conditioned space 6 is reduced.

The rotation speed of the compressor 22 during the refrigerant recovery operation may be higher than the rotation speed of the compressor 22 during the normal operation. For example, the rotation speed of the compressor 22 during the refrigerant recovery operation is set to the maximum rotation speed at the initial stage of the refrigerant recovery operation. By increasing the rotational speed of the compressor 22, the refrigerant can be recovered quickly. Further, during the refrigerant recovery operation, the heat exchange promoting device 27 may operate to promote the heat exchange as compared with the normal operation. For example, during the refrigerant recovery operation, the heat exchange promoting device 27 operates to promote heat exchange most. During the refrigerant recovery operation, the heat exchange promoting device 27 operates to promote heat exchange as compared with the normal operation, so that the refrigerant is easily condensed, so that the refrigerant can be recovered efficiently. .

In step S12, the air conditioning apparatus 100 continues the refrigerant recovery operation until the refrigerant recovery operation ends. The air conditioning apparatus 100 ends the refrigerant recovery operation when the pressure on the suction side of the compressor 22 becomes lower than the first threshold or the pressure on the discharge side of the compressor 22 becomes higher than the second threshold. In the example of this embodiment, when the pressure on the suction side of the compressor 22 becomes equal to or less than the first threshold value 1 kPa, the compressor 22 is stopped and the refrigerant recovery operation is ended. The air conditioning apparatus 100 ends the refrigerant recovery operation when the pressure on the suction side of the compressor 22 becomes lower than the first threshold and the pressure on the discharge side of the compressor 22 becomes higher than the second threshold. It can also be done. When the refrigerant recovery operation is finished, the operation of the air conditioner 100 is stopped in step S14.

According to the air conditioner 100 of the example of this embodiment, after the refrigerant leakage detection device 120 detects the leakage of the refrigerant, the notification device 130 provided in the air conditioning space 6 makes a notification, whereby the air conditioning space 6 is obtained. Since the refrigerant recovery operation is executed with the load-side unit 80 stopped while urging the people inside to escape, the safety when the refrigerant leaks is improved. In the air conditioning apparatus 100 of the example of this embodiment, in the refrigerant recovery operation, the expansion valve unit 60 provided outside the air conditioning space 6 blocks the flow of the refrigerant flowing into the load side unit 80, and the expansion valve unit Since the refrigerant downstream of 60 is moved upstream of the expansion valve unit 60, the safety when the refrigerant leaks is improved.

As described above, the air conditioning apparatus 100 according to the example of this embodiment includes the heat source side unit 20 having the compressor 22 and the heat source side heat exchanger 26, the expansion valve unit 60 having the expansion valve 64, and the load side heat. A load-side unit 80 having an exchanger 82 and performing air conditioning of the air-conditioned space 6, a refrigerant circuit 101 connected by piping and circulating a refrigerant, and a refrigerant leakage detection device 120 detecting leakage of the refrigerant; The expansion valve unit 60 is disposed outside the air conditioning space 6 and in a pipe through which the refrigerant which is condensed by the heat source side heat exchanger 26 functioning as a condenser and flows out from the heat source unit 20 flows. After the leak detection device 120 detects the leak of the refrigerant, the expansion valve 64 is closed. In the air conditioner 100 of the example of this embodiment, when leakage of the refrigerant is detected, the expansion valve unit 60 shuts off the refrigerant, and between the downstream side of the expansion valve unit 60 and the suction side of the compressor 22 The existing refrigerant is stored between the discharge side of the compressor 22 and the upstream of the expansion valve unit 60. Therefore, according to the example of this embodiment, the possibility of the leakage of the refrigerant in the air conditioned space 6 can be reduced, and the influence on the environment by the leakage of the refrigerant to the outside of the air conditioned space 6 can be reduced. Can.

For example, the refrigerant circuit 101 has a relay device 40 relaying the heat source side unit 20 and a plurality of load side units 80, and a plurality of pipes connect the heat source side unit 20 and the relay device 40. The expansion valve unit 60 is disposed in the branch pipe 104. The main valve 102 includes a main pipe 102 and a plurality of branch pipes 104 for connecting the relay device 40 and the plurality of load side units 80, respectively. Ru. When the refrigerant leaks, the refrigerant can be stored not only in the main pipe 102 but also in the branch pipe 104, so the amount of refrigerant stored can be increased. In particular, in the air conditioning apparatus 100 applied to a multi-air-conditioner for buildings and the like, the above effect becomes remarkable because the pipe length is long. Furthermore, in the example of this embodiment, since the expansion valve unit 60 is provided on the branch pipe 104 whose pipe diameter is smaller than that of the main pipe 102, the cost of the expansion valve unit 60 can be reduced.

For example, the refrigerant circuit 101 is disposed between the load side unit 80 functioning as an evaporator and the suction side of the compressor 22, and the refrigerant evaporated by the load side unit 80 functioning as an evaporator is transferred to the compressor 22. It has a backflow prevention device 28 which allows only the flow of the refrigerant to be sucked. By providing the backflow prevention device 28, the risk of the refrigerant flowing back to the air-conditioned space 6 after the refrigerant recovery operation is performed is reduced.

For example, the refrigerant circuit 101 includes an accumulator 30 disposed on the suction side of the compressor 22 and storing the refrigerant, and the accumulator 30 is disposed between the suction side of the compressor 22 and the backflow prevention device 28. It is done. Since the accumulator 30 is provided between the suction side of the compressor 22 and the backflow prevention device 28, the refrigerant stored in the accumulator 30 flows back to the air-conditioned space 6 after performing the refrigerant recovery operation. The risk of the refrigerant leaking is reduced.

For example, the expansion valve unit 60 has a switching device 62 connected in series with the expansion valve 64. With the expansion valve unit 60 configured to have the opening / closing device 62 and the expansion valve 64, the blocking of the refrigerant in the expansion valve unit 60 is ensured. In addition, since the opening and closing device 62 is formed to include the shutoff valve, the shutoff of the refrigerant is further ensured.

For example, the expansion valve 64 is disposed downstream of the switching device 62 when the heat source side heat exchanger 26 functions as a condenser. By providing the expansion valve 64 downstream of the opening / closing device 62, the opening degree of the expansion valve 64 can be adjusted based on the pressure loss when the opening / closing device 62 is open, and the control of the opening degree of the expansion valve 64 can be followed Improves the quality. Furthermore, the expansion valve 64 is disposed downstream of the switching device 62 when the heat source side heat exchanger 26 functions as a condenser, whereby the influence of pressure loss is reduced.

For example, the refrigerant leak detection device 120 includes an indoor sensor 120A which is disposed inside the air-conditioned space 6 and detects a refrigerant leak. When the indoor sensor 120A detects the leakage of the refrigerant in the air-conditioned space 6, the expansion valve unit 60 outside the air-conditioned space 6 shuts off the refrigerant to suppress the leakage of the refrigerant in the air-conditioned space 6, The safety of 6 is improved.

For example, the refrigerant leak detection device 120 includes an outdoor sensor 120B which is disposed in the non-air-conditioned space 4 in which the expansion valve unit 60 outside the air-conditioned space 6 is disposed and which detects the leakage of the refrigerant. When the outdoor sensor 120B detects the leakage of the refrigerant in the non-air-conditioned space 4, the expansion valve unit 60 shuts off the refrigerant to suppress the leakage of the refrigerant in the air-conditioned space 6, whereby the refrigerant leaks to the air-conditioned space 6. Risk is reduced.

For example, after the refrigerant leakage detection device 120 detects the refrigerant leakage, only the load side unit 80 is immediately de-energized, and then the expansion valve 64 is closed. The safety of the air-conditioned space 6 is improved by immediately deenergizing only the load-side unit 80 after the leakage of the refrigerant is detected.

For example, after the refrigerant leakage detection device 120 detects the refrigerant leakage and the expansion valve 64 is closed, the rotational speed of the compressor 22 is higher than before the expansion valve 64 is closed. Become. By increasing the rotational speed of the compressor 22, the refrigerant recovery operation can be completed in a short time. Therefore, the leakage of the refrigerant to the air conditioned space 6 can be suppressed.

For example, the heat exchange promoting device 27 is further provided to promote heat exchange of the heat source side heat exchanger 26, and the refrigerant leakage detection device 120 detects the refrigerant leakage and the heat exchange is performed after the expansion valve 64 is closed. The promoting device 27 promotes heat exchange of the heat source side heat exchanger 26 as compared with before the expansion valve 64 is closed. Since the heat exchange promoting device 27 operates to promote heat exchange of the heat source side heat exchanger 26 as compared with before the expansion valve 64 is closed, the refrigerant is more easily condensed. Recovery can be performed efficiently.

For example, the refrigerant circuit 101 causes the heat source side heat exchanger 26 to function as a condenser and the load side heat exchanger 82 to function as an evaporator, and the heat source side heat exchanger 26 to function as an evaporator. It further has a flow path switching device 24 that switches between the heating operation mode in which the load-side heat exchanger 82 functions as a condenser. Then, when the heating operation mode is being executed, the refrigerant leakage detection device 120 detects the leakage of the refrigerant, and then the mode is switched to the cooling operation mode, after which the expansion valve 64 is closed and the refrigerant recovery operation is performed. Do. Even in the heating operation, since the refrigerant recovery operation is performed after the leakage of the refrigerant is detected, the safety of the air-conditioned space 6 is improved.

For example, when the air conditioning apparatus 100 according to this embodiment uses a refrigerant including a refrigerant having a slight flammability, the above-described effect is particularly remarkable.

Moreover, the expansion valve unit 60 of the example of this embodiment has the heat source side unit 20 which has the compressor 22 and the heat source side heat exchanger 26, and the load which performs the air conditioning of the air-conditioning space 6 having the load side heat exchanger 82. The expansion valve unit 60 is connected to the side unit 80 by piping and forms a refrigerant circuit 101 in which the refrigerant circulates, and includes an expansion valve 64. The expansion valve unit 60 is disposed outside the air conditioning space 6 and in a pipe through which the refrigerant that is condensed by the heat source side heat exchanger 26 functioning as a condenser and flows out from the heat source unit 20 flows. Only by attaching the expansion valve unit 60 of the example of this embodiment, it is possible to obtain the air conditioner 100 capable of suppressing the leakage of the refrigerant.

Note that this embodiment is not limited to the one described above.

[Modification 1]
For example, FIG. 5 is a view showing a modified example 1 which is a modified example of FIG. In addition, in FIG. 5, about the structure same as FIG. 2, the same code | symbol is attached | subjected and description is abbreviate | omitted or simplified. The air conditioning apparatus 100A of Modification 1 shown in FIG. 5 differs from the air conditioning apparatus 100 of the example of Embodiment 1 in the installation location, the installation quantity, and the like of the refrigerant leak detection device 120. That is, air-conditioning apparatus 100A of modification 1 has indoor sensor 120A, load side unit sensor 120A1, and outdoor sensor 120B1. The load-side unit sensor 120A1 is provided in each of the load-side units 80 to detect the leakage of the refrigerant. The load-side unit sensor 120A1 is provided, for example, inside the load-side unit 80, but may be attached to the outside of the load-side unit 80. The outdoor sensor 120B1 is provided in the vicinity of the relay device 40, and detects leakage of the refrigerant. In the first modification, as compared with the example of the first embodiment, since the number of the refrigerant leakage detection devices 120 is large, the detection of the refrigerant leakage is ensured. Furthermore, by increasing the quantity of the refrigerant leakage detection device 120, the estimation of the portion where the refrigerant is leaking is highly accurate. For example, by disposing the outdoor sensor 120B1 so as to overlap the detection area B1 of the outdoor sensor 120B1, the estimation of the portion where the refrigerant is leaking is further enhanced in accuracy. By estimating the location where the refrigerant is leaking, the air conditioning apparatus 100 can be repaired early and restored early after the refrigerant recovery operation. The first modification is not limited to the one described above. For example, in the first modification, the refrigerant leakage detection device 120 may be provided at a place where the detection of the refrigerant leakage can be assured. That is, a plurality of indoor sensors 120A may be provided in the air conditioning space 6, a plurality of load side unit sensors 120A1 may be provided in each of the load side units 80, and the outdoor sensor 120B1 may be provided in the non-air conditioning space 4. It may be provided at each of the locations where leakage of the refrigerant is likely to occur.

[Modification 2]
Further, for example, FIG. 6 is a view showing a modification 2 which is a modification of FIG. In FIG. 6, the same components as those in FIG. 3 are assigned the same reference numerals and descriptions thereof will be omitted or simplified. Compared with the expansion valve unit 60 of the example of Embodiment 1 shown in FIG. 3, the expansion valve unit 60A of the modification 2 shown in FIG. 6 has the 2nd temperature sensor 68A. The second temperature sensor 68 </ b> A detects the temperature of the gas refrigerant that flows into the load side heat exchanger 82 or flows out of the load side heat exchanger 82. As shown in FIG. 6, when the expansion valve unit 60A includes the second temperature sensor 68A, the control of the opening degree of the expansion valve 64 can be performed with high accuracy. The modification 2 is not limited to the one described above. For example, in the second modification, the expansion valve unit 60A may further include a sensor that detects the temperature of the liquid refrigerant that flows into or out of the load-side heat exchanger 82.

Also, for example, in the example of the first embodiment described above, the load side unit 80 may be provided with an expansion valve for expanding the refrigerant. When the load side unit 80 includes the expansion valve, the refrigerant can be decompressed and expanded by the expansion valve of the load side unit 80 and the expansion valve 64 of the expansion valve unit 60. As in the example of the first embodiment, the load-side unit 80 can be miniaturized by configuring the load-side unit 80 without the expansion valve.

Further, for example, in the example of the first embodiment described above, although the example in the case where the heat source side unit 20 is installed in the outdoor 2 is shown, the present invention is not limited to this. For example, the heat source side unit 20 may be installed in an enclosed space such as a machine room having a vent. In addition, as long as waste heat can be exhausted to the outside of the building 8 by an exhaust duct, it may be installed inside the building 8. Alternatively, even when the water-cooled heat source unit 20 is used, it may be installed inside the building 8. Even if the heat source side unit 20 is installed in the place as described above, the above effect is achieved.

Second Embodiment
FIG. 7 is a view showing an example of the configuration of the expansion valve unit of the air conditioning apparatus according to Embodiment 2 of the present invention. In FIG. 7, the same components as in FIG. 3 will be assigned the same reference numerals and descriptions thereof will be omitted or simplified.

As shown in FIG. 7, the expansion valve unit 60B of the example of this embodiment further includes a branch pipe 79, a flow valve 77, and a reservoir 78. The reservoir 78 is a container for storing the refrigerant. The reservoir 78 is connected via the branch piping 79 to the upstream of the opening / closing device 62 and the expansion valve 64 when the heat source side heat exchanger 26 functions as a condenser. In the branch pipe 79, a flow valve 77 is provided. The flow control valve 77 causes the refrigerant to flow through the branch pipe 79 after the refrigerant leakage detection device 120 detects the leakage of the refrigerant and the open / close device 62 or the expansion valve 64 is closed. When the flow valve 77 causes the refrigerant to flow through the branch pipe 79, the refrigerant is stored in the reservoir 78. The flow valve 77 is formed of, for example, an open / close valve, and is opened after the open / close device 62 or the expansion valve 64 is closed. The flow valve 77 may be opened automatically after reaching a predetermined set pressure value, like a relief valve. The branch pipe 79, the flow valve 77, and the reservoir 78 may be provided below the branch portion where the branch pipe 79 branches. By providing the branch pipe 79, the flow valve 77, and the reservoir 78 below the pipe connected to the branch pipe 79, the speed of the refrigerant is increased by its own weight, and the refrigerant is easily stored in the reservoir 78. Therefore, since the refrigerant recovery operation can be terminated immediately, the safety of the air-conditioned space 6 is improved. Furthermore, the reservoir 78 is provided below the pipe connected to the branch pipe 79, whereby the possibility that the refrigerant stored in the reservoir 78 flows back through the branch pipe 79 is suppressed. In order to suppress the possibility of backflow, the branch pipe 79 and the flow valve 77 do not necessarily have to be provided below the pipe connected to the branch pipe 79. In the example of this embodiment, since the expansion valve unit 60B includes the reservoir 78 for storing the refrigerant, the storage amount capable of storing the refrigerant during the refrigerant recovery operation can be increased. Therefore, according to the example of this embodiment, since the rise of the pressure on the high pressure side is suppressed, the recovery of the refrigerant can be ensured, and furthermore, the recovery of the refrigerant can be performed promptly. Since the recovery of the refrigerant can be ensured and the recovery of the refrigerant can be performed promptly, the safety of the air-conditioned space 6 is improved.

As described above, the expansion valve unit 60 in the example of this embodiment is connected to the branch pipe 79 branching from the upstream of the expansion valve 64 when the heat source side heat exchanger 26 functions as a condenser, and the branch pipe 79 And a reservoir 78 for storing the refrigerant. For example, the expansion valve unit 60 is disposed in the branch pipe 79, and after the refrigerant leak detection device 120 detects the refrigerant leakage and the expansion valve 64 is closed, the flow valve 77 flows the refrigerant to the branch pipe 79. have. According to the example of this embodiment, when the leakage of the refrigerant is detected, the reservoir 78 of the expansion valve unit 60 can store the refrigerant, so the amount of refrigerant stored in the refrigerant recovery operation is increased. be able to. Therefore, according to the example of this embodiment, the recovery of the refrigerant can be ensured, and furthermore, the recovery of the refrigerant can be performed promptly. Since the recovery of the refrigerant can be ensured and the recovery of the refrigerant can be performed promptly, the safety of the air-conditioned space 6 is improved.

2 outdoor, 4 non-air conditioned space, 6 air conditioned space, 8 building, 14 heat source side heat exchanger, 20 heat source side unit, 22 compressor, 24 flow path switching device, 26 heat source side heat exchanger, 27 heat exchange promoting machine, 28 backflow prevention device, 30 accumulator, 32 heat source side unit power supply, 33a discharge pressure sensor, 33b suction pressure sensor, 34 heat source side unit power receiving unit, 36 heat source side unit controller, 40 relay device, 60 expansion valve unit, 60A expansion valve Unit, 60B expansion valve unit, 62 opening and closing device, 64 expansion valve, 66 first temperature sensor, 68 second temperature sensor, 68A second temperature sensor, 70 expansion valve unit power supply, 72 expansion valve unit power receiving unit, 74 expansion valve unit Control unit, 77 flow valve, 78 reservoir, 79 branch piping, 80 negative Side unit, 82 load side heat exchanger, 83 blower, 88 load side unit power supply, 90 load side unit power receiving unit, 92 load side unit controller, 100 air conditioner, 100 A air conditioner, 101 refrigerant circuit, 102 main pipe, 104 branch pipe, 120 refrigerant leak detection device, 120A indoor sensor, 120A1 load side unit sensor, 120B outdoor sensor, 120B1 outdoor sensor, 130 alarm device, B1 detection region.

Claims

A heat source side unit having a compressor and a heat source side heat exchanger, an expansion valve unit having an expansion valve, and a load side unit having a load side heat exchanger and performing air conditioning of an air-conditioned space are connected by piping A refrigerant circuit through which
A refrigerant leakage detection device that detects leakage of the refrigerant;
The expansion valve unit is disposed outside the air conditioning space and in the pipe through which the refrigerant that is condensed by the heat source side heat exchanger functioning as a condenser and flows out from the heat source side unit flows. ,
The expansion valve is closed after the refrigerant leakage detection device detects the refrigerant leakage.
Air conditioner.
The refrigerant circuit further includes a relay device that relays the heat source side unit and the plurality of load side units.
The piping has a plurality of main pipes connecting the heat source side unit and the relay device, and a plurality of branch pipes connecting the relay device and each of the plurality of load side units,
The expansion valve unit is disposed in the branch pipe,
The air conditioner according to claim 1.
The refrigerant circuit is disposed between the load side unit functioning as an evaporator and the suction side of the compressor, and the refrigerant evaporated by the load side unit functioning as an evaporator is drawn into the compressor. Further comprising a backflow prevention device that allows only the flow of the
The air conditioning apparatus according to claim 1 or 2.
The refrigerant circuit further includes an accumulator which is disposed on the suction side of the compressor and stores the refrigerant.
The accumulator is disposed between the suction side of the compressor and the backflow prevention device.
The air conditioner according to claim 3.
The expansion valve unit further includes a switching device connected in series with the expansion valve.
The air conditioner according to any one of claims 1 to 4.
The expansion valve is disposed downstream of the opening / closing device when the heat source side heat exchanger functions as a condenser.
The air conditioner according to claim 5.
The expansion valve unit is
A branch pipe branched from the upstream of the expansion valve when the heat source side heat exchanger functions as a condenser;
And a reservoir connected to the branch pipe and storing the refrigerant.
The air conditioner according to any one of claims 1 to 6.
The reservoir is provided below a branch portion where the branch pipe branches.
The air conditioner according to claim 7.
The expansion valve unit is further disposed in the branch pipe, and further includes a flow valve that causes the refrigerant to flow through the branch pipe after the refrigerant leak detection device detects a leak of the refrigerant.
An air conditioner according to claim 7 or 8.
The refrigerant leak detection device has an indoor sensor disposed inside the air conditioning space.
The air conditioner according to any one of claims 1 to 9.
The refrigerant leak detection device has an outdoor sensor disposed in a non-air-conditioned space where the expansion valve unit outside the air-conditioned space is disposed.
An air conditioner according to any one of claims 1 to 10.
After the refrigerant leakage detection device detects the refrigerant leakage, only the load side unit is de-energized, and then the expansion valve is closed.
The air conditioning apparatus according to any one of claims 1 to 11.
After the refrigerant leakage detection device detects leakage of the refrigerant and the expansion valve is closed, the rotational speed of the compressor is higher than before the expansion valve is closed. ,
The air conditioner according to any one of claims 1 to 12.
The heat source side heat exchanger further comprises a heat exchange promoting device for promoting heat exchange of the heat source side heat exchanger,
After the refrigerant leak detection device detects leakage of the refrigerant and the expansion valve is closed, the heat exchange promoting device compares the heat source side as compared to before the expansion valve is closed. Promote heat exchange in the heat exchanger,
The air conditioner according to any one of claims 1 to 13.
The refrigerant circuit causes a cooling operation mode in which the heat source side heat exchanger functions as a condenser and the load side heat exchanger functions as an evaporator, and the heat source side heat exchanger functions as an evaporator and the load The system further includes a flow path switching device that switches between a heating operation mode in which the side heat exchanger functions as a condenser, and
When the heating operation mode is being performed, the refrigerant leakage detection device detects the refrigerant leakage, and then the cooling operation mode is set, and then the expansion valve is closed.
An air conditioner according to any one of the preceding claims.
The refrigerant includes a refrigerant having a slight flammability.
An air conditioner according to any one of the preceding claims.
An expansion valve unit that is connected with a heat source side unit having a compressor and a heat source side heat exchanger and a load side heat exchanger, and is connected with a load side unit that performs air conditioning of the air conditioning space, and forms a refrigerant circuit through which refrigerant circulates And
With expansion valve,
The pipe is disposed outside the air-conditioned space and in the pipe through which the refrigerant that is condensed by the heat source side heat exchanger functioning as a condenser and flows out from the heat source side unit flows.
Expansion valve unit.
And a switching device connected in series with the expansion valve,
The expansion valve unit according to claim 17.
A branch pipe branched from the upstream of the expansion valve when the heat source side heat exchanger functions as a condenser;
And a reservoir connected to the branch pipe and storing the refrigerant.
An expansion valve unit according to claim 17 or 18.