WO2017009955A1

WO2017009955A1 - Refrigeration system

Info

Publication number: WO2017009955A1
Application number: PCT/JP2015/070184
Authority: WO
Inventors: 善生山野; 靖大越
Original assignee: 三菱電機株式会社
Priority date: 2015-07-14
Filing date: 2015-07-14
Publication date: 2017-01-19
Also published as: GB201800132D0; GB2555064A; JP6681896B2; GB2555064B; JPWO2017009955A1

Abstract

The present invention improves the efficiency of a refrigeration system by accurately ascertaining the amount of heat currently in a load-side apparatus. The present invention comprises: a heat pump chiller 1 that includes a water-refrigerant heat exchanger 12 in which heat is exchanged between a refrigerant and a heat medium, and a compressor 11; a load-side apparatus 2; a water circuit 4 in which the water-refrigerant heat exchanger and the load-side apparatus are connected to each other by a pipe and water is caused to circulate by a pump 3 so as to convey the amount of heat supplied by the heat pump chiller to the load-side apparatus; temperature sensors 23a, 23b that detect the temperature of water; pressure sensors 24a, 24b that detect the pressure of water; a suction temperature sensor 25 that detects a load indicator for determining the load in the load-side apparatus; and a control device 30 that controls the respective operations of the compressor and the pump on the basis of values obtained respectively from the temperature sensors, the pressure sensors and the suction temperature sensor.

Description

Refrigeration system

The present invention relates to a refrigeration system using a heat pump chiller as a heat source.

As a refrigeration system using a heat pump chiller as a heat source device, there is an air conditioning system equipped with a water circuit that circulates water as a heat medium in a building such as a building or a large-scale commercial facility. In this type of air conditioning system, water in the water circuit is passed through a fan coil unit or an air handling unit, which is a load side device, and air conditioning is performed with the heat of the water.

It is common to use multiple heat pump chillers and load-side devices for each water circuit. After the water from each load-side device joins at the header, it is distributed to each heat pump chiller to circulate the water. I try to let them.

In order to save power, it is effective to use a heat pump chiller compressor and a water circulation pump that are compatible with inverters. To control these inverters, the water temperature in the header is measured and optimal control is performed for the load. Is building.

Also, in an air conditioning system having a plurality of heat pump chillers, not only inverter control but also the number of operating heat pump chillers is controlled to achieve power saving.

And as a prior example which controls the number of operation | movement of a heat pump chiller by measuring the water temperature in a header for power saving, there exists patent document 1. FIG. Patent Document 1 discloses an air conditioning system that measures the temperature of water in a header and controls only a minimum number of units to operate.

Japanese Patent No. 3320631

The conventional air conditioning system described in Patent Document 1 controls the number of heat pump chillers based only on the water temperature in the header, and the water temperature in the header alone is insufficient as circulating water information for the load side device. . For this reason, it is impossible to accurately grasp the current heat amount of the load side device, that is, the current heat amount that can be supplied from the load side device to the air conditioning load. Therefore, there is a possibility that the heat pump chiller is operated so as to supply an excess amount of heat to the load side device, which causes a reduction in efficiency of the entire air conditioning system.

The present invention has been made to solve the above-described problems, and provides a refrigeration system capable of accurately grasping the current heat amount of a load side device and improving the efficiency of the refrigeration system. With the goal.

In the refrigeration system according to the present invention, a heat source device including a heat source side heat exchanger and a compressor that exchange heat between a refrigerant and a heat medium, a load side device, a heat source side heat exchanger, and a load side device are pipes. A heat medium circuit connected to circulate the heat medium by a pump and conveys the amount of heat supplied by the heat source device to the load side device, a temperature sensor that detects the temperature of the heat medium, and a pressure sensor that detects the pressure of the heat medium A load index sensor for detecting a load index for determining a load in the load side device, and controlling each operation of the compressor and the pump based on values obtained from the temperature sensor, the pressure sensor, and the load index sensor, respectively. And a control device.

According to the present invention, it is possible to obtain a refrigeration system capable of accurately grasping the current heat amount of the load side device and improving the efficiency of the refrigeration system.

It is a block diagram which shows the structure of the air conditioning system which concerns on Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the air conditioning system which concerns on Embodiment 1 of this invention. It is the figure which showed the relationship between the load factor of a compressor, and compressor efficiency. It is a schematic block diagram of the hot water supply system which concerns on Embodiment 2 of this invention. It is a flowchart which shows operation | movement of the hot-water supply system which concerns on Embodiment 2 of this invention.

Embodiment 1 FIG.
As an example of the refrigeration system, the first embodiment will be described here using an air conditioning system.

FIG. 1 is a block diagram showing a configuration of an air conditioning system according to Embodiment 1 of the present invention. The air conditioning system includes a heat pump chiller 1 that is a heat source device installed outdoors, a load-side device 2 that is an indoor unit installed indoors, and a pump 3, and a heat medium in which water as a heat medium circulates. The water circuit 4 which is a circuit is provided. The water circuit 4 is a circuit that transports the heat supplied by the heat pump chiller 1 to the load side device 2 by connecting the heat pump chiller 1 and the load side device 2 with piping and circulating water by the pump 3. In addition, in FIG. 1, although the case where the heat pump chiller 1 and the load side apparatus 2 were each installed 2 each was illustrated, the number of installation is not limited.

The heat pump chiller 1 includes a compressor 11 having an operation capacity variable by an inverter, and a water-refrigerant heat exchanger 12 as a heat source side heat exchanger for heating or cooling circulating water to a target temperature by heat of a refrigerant such as Freon. And. The heat pump chiller 1 has a refrigerant circuit (not shown) including a compressor 11, a decompression device, and a heat exchanger, and the refrigerant in the refrigerant circuit in which the refrigerant circulates and the circulating water in the water circuit 4 are water refrigerant. By performing heat exchange with the heat exchanger 12, the heat exchanger 12 functions as a heat source device that supplies the heat of the refrigerant to the load side device 2. The water circuit 4 is configured such that water circulates between a water refrigerant heat exchanger 12 of the heat pump chiller 1 and a load side heat exchanger 21 a of a fan coil 21 (to be described later) of the load side device 2.

The load side device 2 includes a fan coil 21 and an electric valve 22. The fan coil 21 includes a load side heat exchanger 21a and a fan 21b that allows air to pass through the load side heat exchanger 21a. The fan coil 21 cools the load side air by cooling it by exchanging heat with the circulating water of the water circuit 4 and the load side heat exchanger 21a, and supplying the load side air after cooling into the room. Heating is performed by exchanging heat between the circulating water of the water circuit 4 and the load-side heat exchanger 21a and heating the heated load-side air into the room. The motor-operated valve 22 adjusts the amount of circulating water flowing into the load-side heat exchanger 21a in the water circuit 4.

The load side device 2 further includes a temperature sensor 23 (23a, 23b) that is a heat medium temperature sensor, a pressure sensor 24 (24a, 24b) that is a heat medium pressure sensor, and a suction temperature sensor 25 that is a load index sensor. And a humidity sensor 26.

The temperature sensor 23a is disposed in the water inlet pipe of the load side heat exchanger 21a and detects the temperature of the circulating water at the inlet of the load side heat exchanger 21a. The temperature sensor 23b is disposed in the water outlet pipe of the load side heat exchanger 21a, and detects the temperature of the circulating water at the outlet of the load side heat exchanger 21a.

The pressure sensor 24a is disposed in the water inlet pipe of the load side heat exchanger 21a, and detects the pressure of the circulating water at the inlet of the load side heat exchanger 21a. The pressure sensor 24b is disposed in the water outlet pipe of the load side heat exchanger 21a, and detects the pressure of the circulating water at the outlet of the load side heat exchanger 21a.

The suction temperature sensor 25 is arranged on the windward side of the fan 21b of the fan coil 21, and detects the temperature of the suction air that is load side air. Similarly to the temperature sensor, the humidity sensor 26 is also arranged on the windward side of the fan 21b of the fan coil 21, and detects the humidity of the intake air.

The detection signals of these sensors 23 to 26 are output to a load side control device 27 described later.

The load side device 2 further includes a load side control device 27 that receives detection signals of the sensors 23 to 26, and a central control device 50 that controls the entire air conditioning system.

The load-side control device 27 transmits signals of the sensors 23 to 26 in the load-side device 2 to the central control device 30 described later via the control signal line 31, and calculates the amount of heat necessary for the load-side device 2. To do. The load-side control device 27 can be configured by hardware such as a circuit device that realizes the function, or can be configured by an arithmetic device such as a microcomputer or a CPU, and software executed thereon. it can.

The central control device 30 calculates optimum operating conditions based on information obtained from the heat pump chiller 1, the pump 3, and the load side device 2 connected by the control signal line 31, and the heat pump chiller 1, the pump 3, A driving instruction is output to and controlled. The central control device 30 can be configured by hardware such as a circuit device that realizes the function, or can be configured by an arithmetic device such as a microcomputer or a CPU, and software executed thereon. .

In addition, although the structure which performs operation | movement control of the whole air conditioning system by performing data communication between the load side control apparatus 27 and the central control apparatus 30 was shown here, the load side control apparatus is shown in the central control apparatus 30. The central control device 30 may be configured to perform operation control of the entire air conditioning system. The load side control device 27 and the central control device 30 constitute a control device according to the present invention.

FIG. 2 is a flowchart showing the operation of the air conditioning system according to Embodiment 1 of the present invention.
In the air conditioning system configured as described above, the temperature and humidity of the intake air are detected using the intake temperature sensor 25 and the humidity sensor 26 (S1). Then, the load-side control device 27 determines whether the intake air temperature detected by the intake temperature sensor 25 matches the target temperature (S2). The intake air temperature detected by the intake temperature sensor 25 corresponds to a load index for determining the current load on the load side. Then, if the intake air temperature does not match the target temperature, the load-side control device 27 calculates the amount of heat necessary for making the intake air temperature the target temperature by using the intake air temperature sensor 25 and the humidity sensor 26. Calculation is performed based on the temperature and humidity (S3).

In calculating this “necessary heat quantity”, the heat quantity can be calculated more accurately by using the suction air humidity in addition to the suction air temperature. That is, for example, when cooling a place where the temperature and humidity are high, it is necessary to take heat including latent heat in order to cool the air while changing the water vapor in the air to water. For this reason, when the humidity is high, more cooling capacity is required than when the humidity is low. Thus, more accurate “necessary amount of heat” can be calculated by considering latent heat. From the above viewpoint, it is preferable to use the intake air humidity in calculating the “necessary heat amount”, but at least the intake air temperature may be used.

Next, the load-side control device 27 uses the temperature sensor 23 and the pressure sensor 24 to detect the water temperature and water pressure of the circulating water, and the “current heat amount that can be supplied from the load-side heat exchanger 21a to the air conditioning load”. Calculate (S4). Hereinafter, the water temperature and water pressure information of the circulating water may be referred to as load-side control information.

Then, the load-side control device 27 determines whether the “necessary amount of heat” can be obtained by adjusting the opening degree of the motor-operated valve 22 and changing the flow rate of the circulating water flowing to the load-side heat exchanger 21a. (S5). Specifically, this determination is made by comparing the difference between the “necessary heat amount” and the “current heat amount that can be supplied from the load-side heat exchanger 21a to the air conditioning load” with a preset heat amount. That is, when the difference between the “necessary heat amount” and the “current heat amount that can be supplied from the load-side heat exchanger 21a to the air conditioning load” is smaller than the set heat amount, the opening degree of the motor-operated valve 22 is adjusted and the load-side heat is adjusted. It is determined that the “necessary amount of heat” can be obtained by changing the flow rate flowing through the exchanger 21a. On the other hand, when the difference between the “necessary heat amount” and the “current heat amount that can be supplied from the load-side heat exchanger 21 a to the air conditioning load” is larger than the set heat amount, the load-side control device 27 opens the opening degree of the motor-operated valve 22. It is judged that “necessary heat quantity” cannot be obtained by adjustment.

If the load-side control device 27 determines that the “necessary heat amount” can be obtained by adjusting the opening degree of the motor-operated valve 22, the load-side control device 27 adjusts the opening degree of the motor-operated valve 22 according to the “necessary heat amount” (S6). Return to step S4.

On the other hand, when the load-side control device 27 determines that the “necessary amount of heat” cannot be obtained by adjusting the opening degree of the motor-operated valve 22, the load-side control device 27 controls the information indicating that the operating condition needs to be changed. The signal is transmitted to the central controller 30 via the signal line 31. Here, when transmitting information that the operating condition needs to be changed from the load-side control device 27 to the central control device 30, the current load-side control obtained by the load-side device 2 is added to this information. The information (including circulating water temperature and pressure) is also transmitted.

The processes in steps S1 to S6 are performed by each load side control device 27. Therefore, according to the amount of heat in each load-side control device 27, the information (including load-side control information) that the operation condition needs to be changed from a part or all of each load-side control device 27 is central. It will be collected in the control device 30.

Then, the central control device 30 is based on the operation information obtained from the heat pump chiller 1 and the pump 3 and the load side control information (water temperature and water pressure of the circulating water) obtained from each load side control device 27 of the load side device 2. The operation of each heat pump chiller 1 and pump 3 is controlled. That is, an optimal operation condition is calculated based on the operation information and the load side control information, and an operation instruction is output to each of the heat pump chillers 1 and the pump 3 (S7). The operation information obtained from the heat pump chiller 1 and the pump 3 specifically corresponds to the current operation capacity, for example.

Here, since the efficiency of the compressor 11 has the most influence on the realization of power saving of the air conditioning system, the central control device 30 determines the operation instruction so that the plurality of compressors 11 are operated at an efficient load factor. To do. FIG. 3 shows the load factor of the compressor 11.

FIG. 3 is a diagram showing the relationship between the compressor load factor and the compressor efficiency. In the case of the compressor 11 having the relationship shown in FIG. 3, when the load factor in rated operation is 100%, the efficiency around 50% is good. For this reason, for example, 10 heat pump chillers 1 are installed, and when all 10 units are operated at a load factor of 100%, assuming that the operation request is 100%, 5 units are loaded to realize the operation request 50%. This can be done by driving at a rate of 100%. However, since the compressor 11 has better compression efficiency when operated at a load factor of 50% than when operated at a load factor of 100%, ten compressors 11 are operated at a load factor of 50%. Further, when the operation request is 40%, the eight compressors may be operated at a load factor of 50%.

The operation request rate is obtained by calculating the operation information obtained from the heat pump chiller 1 and the pump 3 and the load side control information (water temperature and water pressure of the circulating water) obtained from the load side device 2 in the central control device 30. The compressor 11 is controlled so that the load factor of the compressor 11 is optimized based on the required operation amount.

The compressor 11 of the heat pump chiller 1 is operated with the operation number and the operation capacity optimized based on the above concept. In other words, the central controller 30 is configured to operate the compressor 11 under the optimum operating conditions (operation of the compressor 11) so that the compressor 11 is operated within a set load factor range including a load factor (50% here) at which the compressor efficiency is maximum. Number and operating capacity of the compressor 11).

In addition, the central control device 30 maintains the minimum water circulation amount for operation in the water circuit 4 based on the water pressure obtained from the pressure sensor 10 of the load side device 2, and the outlet water temperature of the heat pump chiller 1 becomes the set water temperature. The operation capacity of the pump 3 is controlled so as to obtain a water circulation amount optimized so as to be maintained.

As described above, according to the first embodiment, the amount of heat on the load side, that is, the “current amount of heat that can be supplied from the load-side heat exchanger 21a to the air conditioning load” can be grasped using the water temperature and the water pressure of the circulating water. Therefore, it is possible to accurately grasp the temperature compared with the conventional method using only the circulating water temperature.

Then, based on the “necessary heat amount”, the operation information of the heat pump chiller 1 and the pump 3 and the load side control information (water temperature and water pressure of the circulating water), the operating capacity of the compressor 11 and the amount of circulating water are optimized. Therefore, the effect of improving the efficiency of the entire air conditioning system can be obtained.

Further, in calculating the “necessary amount of heat”, the amount of heat can be calculated more accurately by using the suction air humidity detected by the humidity sensor 26 in addition to the suction air temperature detected by the suction temperature sensor 25. By calculating the “necessary heat amount” using humidity in this way during cooling, comfortable air conditioning considering humidity can be performed with high efficiency.

If the difference between the “necessary heat amount” and the “current heat amount that can be supplied from the load-side heat exchanger 21a to the air conditioning load” is smaller than the set heat amount, the operating conditions of the compressor 11 and the pump 3 are changed. At least, the “necessary amount of heat” can be obtained by controlling the motor-operated valve 22.

Further, based on the water pressure detected by the pressure sensor 24, a pump is provided so that the outlet water temperature of the load-side heat exchanger 21a is maintained at the set water temperature while maintaining the minimum circulation amount required for operation in the water circuit 4. 3 can be controlled.

In addition, by adding a user interface to the central control device 30 to prepare a monitoring environment, there is an effect that energy management and system monitoring can be performed to ensure high efficiency of the entire air conditioning system.

In the first embodiment, the heat medium circulating in the water circuit 4 is water, but it can be replaced with water or the like mixed with an additive that lowers the freezing point.

Embodiment 2. FIG.
Although the said Embodiment 1 mentioned the air-conditioning system as an example of a refrigeration system, Embodiment 2 demonstrates the example of a hot-water supply system.

FIG. 4 is a schematic configuration diagram of a hot water supply system according to Embodiment 2 of the present invention.
The hot water supply system includes a heat pump chiller 41 that is a heat source functioning as a hot water supply device, a sealed tank 42 that is a hot water storage tank for storing water heated by the heat pump chiller 41, and water heated by the heat pump chiller 41. Is stored in the sealed tank 42, and a water circuit 44 that is a hot water supply circuit that supplies the hot water supply terminal 43 is provided. The sealed tank 42 corresponds to the load side device of the present invention.

The water circuit 44 includes a water circuit 44a and a water circuit 44b. The water circuit 44 a is a circuit that transports heat supplied from the heat pump chiller 1 to the sealed tank 42 by connecting the heat pump chiller 41 and the sealed tank 42 with piping and circulating water by the pump 49. The water circuit 44b is a circuit in which the sealed tank 42 and the hot water supply terminal 43 are connected by piping and water is circulated by a pump 45 that is a hot water supply terminal side pump.

The hot water supply terminal 43 is, for example, a shower or a currant. Although FIG. 4 shows a case where three heat pump chillers 1 are installed and one sealed tank 42 is installed, the number of installed units is not limited.

The structure of the heat pump chiller 41 is the same as that of the heat pump chiller 1 of the first embodiment shown in FIG. 1, and the water is heated to a target temperature by the compressor 11 whose operating capacity is variable by an inverter and the heat of a refrigerant such as flon. And a water-refrigerant heat exchanger 12. The heat pump chiller 41 includes a refrigerant circuit (not shown) including the compressor 11, a decompression device, and a heat exchanger, and the refrigerant in the refrigerant circuit in which the refrigerant circulates and the water in the water circuit 44a are water refrigerant heat. By exchanging heat with the exchanger 12, it functions as a heat source device that supplies the heat of the refrigerant to the sealed tank 42.

The water circuit 44b is provided with a temperature sensor 46 (46a, 46b) which is a heat medium temperature sensor and a pressure sensor 47 (47a, 47b) which is a heat medium pressure sensor.

The temperature sensor 46 a is disposed in the water inlet pipe of the sealed tank 42 and detects the temperature of the circulating water at the inlet of the sealed tank 42. The temperature sensor 46 b is disposed in the water outlet pipe of the sealed tank 42 and detects the temperature of the circulating water at the outlet of the sealed tank 42. The temperature sensor 46b constitutes a load index sensor of the present invention.

The pressure sensor 47 a is disposed in the water inlet pipe of the sealed tank 42 and detects the pressure of the circulating water at the inlet of the sealed tank 42. The pressure sensor 47 b is disposed in the water outlet pipe of the sealed tank 42 and detects the pressure of the circulating water at the outlet of the sealed tank 42.

The detection signals of these sensors 46 and 47 are output to a load side control device 48 described later.

The hot water supply system further includes a load-side control device 48 that receives detection signals from the sensors 46 and 47, and a central control device 50 that controls the entire hot water supply system.

The load-side control device 48 transmits the signals of the sensors 46 and 47 to the central control device 50 via the control signal line 51, and the amount of heat necessary for maintaining the temperature in the sealed tank 42 at the target water temperature. Or calculate. A pump 45 is connected to the load side control device 48. The load-side control device 48 can be configured by hardware such as a circuit device that realizes the function, or can be configured by an arithmetic device such as a microcomputer or a CPU, and software executed thereon. it can.

The central control device 50 is connected to the heat pump chiller 41 and the load side control device 48 by a control signal line 51, and is optimal based on information obtained from each of the heat pump chiller 41, the pump 45, and the load side control device 48. An operation condition is calculated and an operation instruction is output to the heat pump chiller 41 and the pump 45. The central control device 50 can be configured by hardware such as a circuit device that realizes the function, or can be configured by an arithmetic device such as a microcomputer or a CPU and software executed on the arithmetic device. .

In addition, although the structure which performs the data communication between the load side control apparatus 48 and the central control apparatus 50 and performs a cooperation process was shown here, operation control of the whole hot water supply system was shown. 48 functions may also be provided, and the central controller 50 may control the operation of the entire hot water supply system. The load side control device 48 and the central control device 50 constitute a control device according to the present invention.

FIG. 5 is a flowchart showing the operation of the hot water supply system according to Embodiment 2 of the present invention.
In the hot water supply system configured as described above, the temperature and water pressure of the circulating water are detected using the temperature sensor 46 and the pressure sensor 47 (S11). Then, the load side control device 48 determines whether or not the outlet water temperature of the closed tank 42 detected by the temperature sensor 46b matches the target water temperature (S12). The outlet water temperature detected by the temperature sensor 46b corresponds to a load index for determining the current load on the load side. Then, if the outlet water temperature does not match the target water temperature, the load-side control device 48 determines the “necessary heat amount” necessary for maintaining the outlet water temperature at the target temperature based on the detection results of the temperature sensor 46 and the pressure sensor 47. Calculate (S13). The “necessary heat amount” is calculated based on “the current heat amount that can be supplied from the sealed tank 42 to the hot water supply load”. Specifically, the load-side control device 48 calculates based on the temperature difference between the outlet water temperature and the target water temperature and the detection results of the temperature sensor 46 and the pressure sensor 47.

The amount of heat required to maintain the water temperature in the sealed tank 42 at the target water temperature is also affected by the amount of heat flowing out of the hot water supply terminal 43, but the effect appears in the values of the temperature sensor 46 and the pressure sensor 47. For this reason, by using the values of the temperature sensor 46 and the pressure sensor 47, the amount of heat necessary to maintain the water temperature in the sealed tank 42 at the target water temperature, taking into consideration the amount of heat flowing out of the hot water supply terminal 43, can be obtained. Can be calculated.

The load-side control device 48 transmits the calculated “necessary heat amount” information to the central control device 50 via the control signal line 51.

The central controller 50 calculates the optimum operating conditions based on the “necessary amount of heat” transmitted from the load-side controller 48 and the operation information of the heat pump chiller 41, and the compressor 11 and the pump 49 of each heat pump chiller 41. An operation instruction is output to (S14), and each operation capacity is controlled. The concept for determining the number of operating compressors 11 of each heat pump chiller 41 and the operating capacities of the compressors 11 and the pumps 49 is the same as in the first embodiment.

Also, the load side control device 48 detects a pressure drop in the water circuit 44b due to the use of the hot water supply terminal 43 by a pressure sensor 47 disposed in the water circuit 44b. Then, the load-side control device 48 controls the operating capacity of the pump 45 based on the detected water pressure so that a water circulation amount optimized to maintain the water pressure of the hot water supply terminal 43 at the set water pressure is obtained.

In addition, even when the hot water supply terminal 43 is not used, it is necessary to circulate water to the vicinity of the hot water supply terminal 43 so that hot water can be discharged immediately at the time of use. At that time, the load-side control device 48 operates the pump 45 at a necessary minimum so as to keep the temperature difference of the temperature sensor 46 at the inlet / outlet of the sealed tank 42 constant.

As described above, according to the second embodiment, the current amount of heat and the necessary amount of heat that can be supplied from the sealed tank 42 to the hot water supply load are calculated using the water temperature and pressure of the circulating water and the load index. Compared to the conventional method using only the water temperature, it is possible to accurately grasp the amount of heat. As a result, since the operating capacity and the amount of circulating water can be adjusted optimally, the effect of increasing the efficiency of the entire air conditioning system can be obtained.

In addition, a hot water supply system that can maintain the water pressure of the hot water supply terminal 43 can be realized by arranging the pressure sensor 47 in the water inlet pipe and the water outlet pipe of the sealed tank 42 and issuing an operation instruction to the pump 45. When the hot water supply terminal 43 is not used, the temperature sensor 46 is disposed in the water inlet pipe and the water outlet pipe of the sealed tank 42, and the pump 45 is operated at the minimum necessary, so that the water circuit 44b is kept warm. Power saving can be realized.

By the way, the system described in the first embodiment and the second embodiment uses a heat pump chiller having a heat exchanger for heating or cooling water to a target temperature with the heat of a refrigerant such as chlorofluorocarbon as a heat source device. However, the refrigeration system of the present invention is not limited to one using the heat pump chiller as a heat source device. In addition, for example, it is needless to say that the present invention can be applied to a system using other chillers, boilers, and electric water heaters as heat sources.

1 heat pump chiller, 2 load side device, 3 pump, 4 water circuit, 5 control signal line, 6 control device, 7 relay board, 10 pressure sensor, 11 compressor, 12 water refrigerant heat exchanger, 21 fan coil, 21a load Side heat exchanger, 21b fan, 22 motor operated valve, 23 (23a, 23b) temperature sensor (heat medium temperature sensor), 24 (24a, 24b) pressure sensor (heat medium pressure sensor), 25 suction temperature sensor, 26 humidity sensor , 27 Load side control device, 30 Central control device, 31 Control signal line, 41 Heat pump chiller, 42 Sealed tank, 43 Hot water supply terminal, 44 (44a, 44b) Water circuit, 45 pump, 46 (46a, 46b) Temperature sensor (Heat medium temperature sensor), 47 (47a, 47b) Pressure sensor (Heat medium pressure sensor) , 48 load-side control unit, 49 a pump, 50 a central control unit, 51 control signal lines.

Claims

A heat source device having a heat source side heat exchanger and a compressor for heat exchange between the refrigerant and the heat medium; and
A load side device;
A heat medium circuit that connects the heat source side heat exchanger and the load side device by piping and circulates the heat medium by a pump, and conveys the amount of heat supplied by the heat source unit to the load side device;
A heat medium temperature sensor for detecting the temperature of the heat medium;
A heat medium pressure sensor for detecting the pressure of the heat medium;
A load index sensor for detecting a load index for determining a load in the load side device;
A refrigeration system comprising: a control device that controls operation of each of the compressor and the pump based on values obtained from the heat medium temperature sensor, the heat medium pressure sensor, and the load index sensor.
The load-side device includes a fan coil having a load-side heat exchanger and a fan, and the piping is connected to the load-side heat exchanger so that the heat medium in the heat medium circuit circulates. And
The heat medium temperature sensor is a temperature sensor that detects the temperature of the heat medium at the entrance and exit of the load-side heat exchanger,
The heat medium pressure sensor is a pressure sensor that detects a pressure at an inlet / outlet of the heat medium of the fan coil,
The refrigeration system according to claim 1, wherein the load index sensor is a suction temperature sensor that detects a temperature of air sucked into the fan coil.
A humidity sensor for detecting the humidity of the air sucked into the fan coil;
The refrigeration system according to claim 2, wherein the control device further controls operation of the compressor and the pump by further using humidity detected by the humidity sensor.
The control device controls the operation of the compressor and the pump using the humidity detected by the humidity sensor, heats the heat medium and air with the fan coil, cools the air, and supplies the air indoors. The refrigeration system according to claim 3, which is performed during cooling.
An electric valve for adjusting the flow rate of the heat medium flowing into the load-side heat exchanger of the fan coil;
The control device has a difference between the amount of heat necessary for setting the suction temperature detected by the suction temperature sensor to the target temperature and the amount of heat that can be supplied from the load side device to the air conditioning load, based on a preset set amount of heat. If the difference is larger than the set heat amount, the compressor and the pump are operated so that the necessary heat amount is obtained. The refrigeration system according to any one of claims 2 to 4, which is controlled.
Based on the pressure detected by the heat medium pressure sensor, the control device maintains the minimum amount of circulation required for operation in the heat medium circuit, and the outlet water temperature of the load-side heat exchanger becomes a set water temperature. The refrigeration system according to any one of claims 2 to 5, wherein operation of the pump is controlled so as to be maintained.
The heat medium is water, and the load side device is a hot water storage tank,
The heat medium circuit is a hot water supply circuit that stores the water heated by the heat source side heat exchanger in the hot water storage tank and supplies the hot water supply terminal to the hot water supply terminal,
The heat medium temperature sensor is a temperature sensor that detects the water temperature at the inlet / outlet of the hot water storage tank, and the heat medium temperature sensor that detects the outlet water temperature of the hot water storage tank also serves as the load index sensor,
The refrigeration system according to claim 1, wherein the heat medium pressure sensor is a pressure sensor that detects a pressure at an inlet / outlet of the hot water storage tank.
In the hot water supply circuit, a hot water supply terminal side pump for circulating water between the hot water storage tank and the hot water supply terminal,
The control device controls the hot water supply terminal side pump to maintain the water pressure of the hot water supply circuit at a set water pressure when the heat medium pressure sensor detects a decrease in water pressure of the hot water supply circuit when the hot water supply terminal is used. The refrigeration system according to claim 7.
The refrigeration system according to claim 8, wherein the control device operates the hot-water supply terminal side pump with a necessary minimum so as to keep a temperature difference of water at the entrance and exit of the hot water storage tank constant.
A plurality of the heat source machines are provided,
The control device uses the information indicating the relationship between the compressor load factor and the compressor efficiency, and uses a plurality of the heat source devices within a set load factor range including a load factor at which the compressor efficiency is maximized. The refrigeration system according to any one of claims 1 to 9, wherein an operation number of the compressors and an operation capacity of the compressors are determined so that the compressors are operated.