阅读说明：本技术 制冷剂状态检测装置、制冷剂状态检测方法和温度调节系统 (Refrigerant state detection device, refrigerant state detection method, and temperature adjustment system ) 是由 山口俊二 峰原亨明 深井健太 于 2020-04-30 设计创作，主要内容包括：[课题]实施方式的制冷剂状态检测装置(40A)具备：温度信息获取部(41),其在具有压缩机、冷凝器、膨胀阀和蒸发器的制冷回路中获取从上述冷凝器流出的制冷剂的温度,并且获取在上述冷凝器中冷却上述制冷剂的冷却用流体在冷却上述制冷剂之前的温度；和制冷剂状态判定部(42),其在由温度信息获取部(41)获取到的上述制冷剂的温度与上述冷却用流体的温度之差大于预先存储的阈值的情况下,判定为发生了上述制冷剂的泄漏或者不足。([ problem ] A refrigerant state detection device (40A) according to an embodiment is provided with: a temperature information acquisition unit (41) that acquires, in a refrigeration circuit having a compressor, a condenser, an expansion valve, and an evaporator, the temperature of a refrigerant flowing out of the condenser, and that acquires the temperature of a cooling fluid that cools the refrigerant in the condenser before cooling the refrigerant; and a refrigerant state determination unit (42) that determines that leakage or shortage of the refrigerant has occurred when the difference between the temperature of the refrigerant acquired by the temperature information acquisition unit (41) and the temperature of the cooling fluid is greater than a pre-stored threshold value.)

1. A refrigerant state detection device is provided with:

a temperature information acquisition unit that acquires, in a refrigeration circuit having a compressor, a condenser, an expansion valve, and an evaporator, a temperature of a refrigerant flowing out of the condenser, and acquires a temperature of a cooling fluid that cools the refrigerant in the condenser before cooling the refrigerant; and

and a refrigerant state determination unit that determines that leakage or shortage of the refrigerant has occurred when a difference between the temperature of the refrigerant acquired by the temperature information acquisition unit and the temperature of the cooling fluid is greater than a threshold value stored in advance.

2. The refrigerant state detection device according to claim 1, wherein the condenser is a liquid-cooled heat exchanger, and the cooling fluid is a liquid.

3. The refrigerant state detection device according to claim 1 or 2,

the condenser has a first condensing part and a second condensing part that condenses the refrigerant flowing out of the first condensing part,

the temperature information acquisition unit acquires the temperature of the refrigerant flowing out of the second condensation unit and the temperature of the cooling fluid that cools the refrigerant in the second condensation unit before cooling the refrigerant.

4. A refrigerant state detection method includes:

a temperature information acquisition process: acquiring, in a refrigeration circuit having a compressor, a condenser, an expansion valve, and an evaporator, a temperature of a refrigerant flowing out of the condenser, and acquiring a temperature of a cooling fluid that cools the refrigerant in the condenser before cooling the refrigerant; and

a refrigerant state determination step: when the difference between the temperature of the refrigerant obtained in the temperature information obtaining step and the temperature of the cooling fluid is greater than a threshold value stored in advance, it is determined that leakage or shortage of the refrigerant has occurred.

5. The refrigerant state detection method according to claim 4, further comprising a charging step of: when the temperature of the refrigerant flowing out of the condenser is acquired and the temperature of the cooling fluid for cooling the refrigerant in the condenser is acquired before the refrigerant is cooled, the refrigerant is charged into the refrigeration circuit by a predetermined amount that enables operation of the refrigeration circuit in which the difference between the acquired temperatures is equal to or less than the threshold value;

the leakage or shortage of the refrigerant is determined by the temperature information acquisition step and the refrigerant state determination step performed after the charging step.

6. The refrigerant state detection method according to claim 5, wherein, during operation of the refrigeration circuit after the charging step, the refrigeration circuit cools the refrigerant in the condenser such that the refrigerant condensed in the condenser covers an outlet of the condenser.

7. A temperature adjustment system is provided with:

a refrigeration circuit having a compressor, a condenser, an expansion valve, and an evaporator; and

a refrigerant condition detection device according to any one of claims 1 to 3.

8. The temperature adjustment system according to claim 7, wherein the refrigeration circuit is configured to be capable of performing an operation in which a difference between the temperature of the refrigerant acquired by the refrigerant state detection device and the temperature of the cooling fluid is equal to or less than the threshold value when a predetermined amount of the refrigerant is filled.

9. The temperature adjustment system according to claim 8, wherein the refrigeration circuit is capable of cooling the refrigerant in the condenser in such a manner that the refrigerant condensed in the condenser covers an outlet of the condenser in a state in which the refrigerant is filled with the prescribed amount.

10. The temperature control system according to any one of claims 7 to 9, further comprising a fluid circulating device for circulating a fluid whose temperature is controlled by the evaporator.

Technical Field

The invention relates to a refrigerant state detection device, a refrigerant state detection method and a temperature adjustment system.

Background

In the case where the refrigerant leaks from the refrigeration circuit and the refrigerant becomes insufficient, there is a possibility that a problem such as a decrease in cooling capacity occurs, and therefore, it is preferable to take some measure as soon as possible.

Various techniques for detecting refrigerant leakage have been proposed. For example, JP2016-121867a discloses the following technique: the refrigerant leakage is detected by detecting a compressor suction pressure, an evaporator pressure, a compressor discharge pressure, a condenser pressure, a compressor suction temperature, an evaporator outlet temperature, a compressor discharge temperature, a condenser inlet temperature, and the like, and using these detected values as parameters. WO2017/175300 discloses a technique in which a refrigerant detection device that detects a refrigerant leaking to the outside is provided in an indoor unit of an air conditioner.

Disclosure of Invention

Technical problem to be solved by the invention

However, the technique of JP2016-121867a requires a large number of sensors for detecting pressure, temperature, and the like, and also has many parameters for determining refrigerant leakage. Further, in the technique of WO2017/175300, since the refrigerant leaking to the outside is directly detected by the refrigerant detection device, it is difficult to detect the refrigerant leaking at a position distant from the refrigerant detection device, and it is hard to say that the shortage of the refrigerant can be accurately detected.

In view of the known technologies described above, the inventors of the present application have made intensive studies to detect leakage of the refrigerant or shortage of the refrigerant as accurately as possible. Further, it was found that in the case where the refrigerant was insufficient, the outlet temperature of the condenser was higher than that in the case where the refrigerant was not insufficient. Moreover, it was found that this phenomenon is generated as follows: when the refrigerant is insufficient, the amount of refrigerant condensed in the condenser is smaller than a predetermined or expected amount of refrigerant, and the high-temperature refrigerant in a gaseous state is likely to be mixed into the downstream pipe from the outlet of the condenser.

The present invention has been made in view of the above-described findings, and an object thereof is to provide a refrigerant state detection device, a refrigerant state detection method, and a temperature adjustment system, which can simply and accurately detect leakage or shortage of refrigerant in a refrigeration circuit.

Means for solving the problems

The refrigerant state detection device of the present invention includes: a temperature information acquisition unit that acquires, in a refrigeration circuit including a compressor, a condenser, an expansion valve, and an evaporator, a temperature of a refrigerant flowing out of the condenser, and acquires a temperature of a cooling fluid that cools the refrigerant in the condenser before cooling the refrigerant; and a refrigerant state determination unit that determines that leakage or shortage of the refrigerant has occurred when a difference between the temperature of the refrigerant acquired by the temperature information acquisition unit and the temperature of the cooling fluid is greater than a threshold value stored in advance.

The condenser may be a liquid-cooled heat exchanger, and the cooling fluid may be a liquid.

The condenser may include a first condensation unit and a second condensation unit that condenses the refrigerant flowing out of the first condensation unit, and the temperature information acquisition unit may acquire a temperature of the refrigerant flowing out of the second condensation unit and a temperature of the cooling fluid that cools the refrigerant in the second condensation unit before cooling the refrigerant.

The refrigerant state detection method of the present invention includes: a temperature information acquisition step of acquiring, in a refrigeration circuit including a compressor, a condenser, an expansion valve, and an evaporator, a temperature of a refrigerant flowing out of the condenser, and acquiring a temperature of a cooling fluid that cools the refrigerant in the condenser before cooling the refrigerant; and a refrigerant state determination step of determining that leakage or shortage of the refrigerant has occurred when a difference between the temperature of the refrigerant obtained in the temperature information obtaining step and the temperature of the cooling fluid is greater than a threshold value stored in advance.

The refrigerant state detection method of the present invention may further include a filling step of filling the refrigeration circuit with a predetermined amount of the refrigerant, which is capable of performing an operation of the refrigeration circuit in which a difference between the acquired temperatures is equal to or less than the threshold value, when the temperature of the refrigerant flowing out of the condenser is acquired and the temperature of the cooling fluid for cooling the refrigerant in the condenser is acquired before the refrigerant is cooled; the leakage or shortage of the refrigerant is determined by the temperature information acquisition step and the refrigerant state determination step performed after the charging step.

In the refrigeration circuit after the charging step, the refrigeration circuit may cool the refrigerant in the condenser so that the refrigerant condensed in the condenser covers an outlet of the condenser.

The temperature control system of the present invention comprises: a refrigeration circuit having a compressor, a condenser, an expansion valve, and an evaporator; and the refrigerant state detection device described above.

The refrigeration circuit may be configured to perform an operation in which, when a predetermined amount of the refrigerant is filled, a difference between the temperature of the refrigerant obtained by the refrigerant state detection device and the temperature of the cooling fluid is equal to or less than the threshold value.

When the predetermined amount of the refrigerant is charged, the refrigeration circuit may be configured to cool the refrigerant in the condenser so that the refrigerant condensed in the condenser covers an outlet of the condenser.

The temperature control system of the present invention may further include a fluid circulating device for circulating the fluid whose temperature is controlled by the evaporator.

Effects of the invention

According to the present invention, leakage or shortage of the refrigerant in the refrigeration circuit can be detected simply and accurately.

Drawings

Fig. 1 is a diagram showing a schematic configuration of a temperature control system according to a first embodiment of the present invention.

Fig. 2A is a schematic cross-sectional view of a condenser provided in the refrigeration circuit of the temperature regulation system shown in fig. 1.

Fig. 2B is a schematic cross-sectional view of a condenser provided in the refrigeration circuit of the temperature regulation system shown in fig. 1.

Fig. 3 is a diagram showing a schematic configuration of a temperature control system according to a second embodiment of the present invention.

Fig. 4 is a diagram showing a schematic configuration of a temperature control system according to a third embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described.

(first embodiment)

Fig. 1 is a diagram showing a schematic configuration of a temperature control system 1 according to a first embodiment of the present invention. The temperature control system 1 of the present embodiment includes a refrigeration circuit 10, a first cooling fluid circulation device 21, a second cooling fluid circulation device 22, a temperature control target fluid circulation device 30, and a controller 40.

The refrigeration circuit 10 has a compressor 11, a condenser 12, a reservoir 13, an expansion valve 14, and an evaporator 15. The compressor 11, the condenser 12, the reservoir 13, the expansion valve 14, and the evaporator 15 are connected by piping members to circulate the refrigerant in this order.

The compressor 11 compresses the refrigerant in a low-temperature and low-pressure gas state flowing out of the evaporator 15 to a high-temperature and high-pressure gas state, and supplies the compressed refrigerant to the condenser 12. The condenser 12 cools and condenses the refrigerant compressed by the compressor 11 with a cooling fluid, and turns the refrigerant into a high-pressure liquid state at a predetermined cooling temperature.

In the present embodiment, the condenser 12 includes a first condensing unit 121 and a second condensing unit 122 that condenses the refrigerant flowing out of the first condensing unit 121. The refrigerant passing through the first condensation unit 121 is cooled by the first cooling fluid supplied to the first condensation unit 121 by the first cooling fluid circulation device 21. The refrigerant passing through the second condensation portion 122 is cooled by the second cooling fluid supplied to the second condensation portion 122 by the second cooling fluid circulation device 22.

The first condensation unit 121 and the second condensation unit 122 are each constituted by a liquid-cooled heat exchanger, specifically, a plate heat exchanger. However, the first and second condensing units 121 and 122 may be formed of air-cooled heat exchangers.

The receiver 13 receives and stores the refrigerant condensed into liquid by the condenser 12, and the refrigerant stored in the receiver 13 flows toward the expansion valve 14. The expansion valve 14 reduces the pressure by expanding the refrigerant supplied from the receiver 13, and supplies the refrigerant to the evaporator 15 in a low-temperature and low-pressure liquid state or a gas-liquid mixed state. In the present embodiment, the evaporator 15 exchanges heat between the supplied refrigerant and the temperature adjustment target fluid flowing through the temperature adjustment target fluid flowing device 30. The refrigerant that has exchanged heat with the fluid to be temperature-regulated becomes a low-temperature and low-pressure gas state, flows out of the evaporator 15, and is compressed again by the compressor 11.

The first cooling fluid circulation device 21 supplies the first cooling fluid to the first condensation unit 121, and the second cooling fluid circulation device 22 supplies the second cooling fluid to the second condensation unit 122. As described above, in the present embodiment, since the first condenser 121 and the second condenser 122 are constituted by liquid-cooled heat exchangers, liquid is used as the first cooling fluid and the second cooling fluid.

The first cooling fluid and the second cooling fluid as liquids may be water or other fluids. When the first condenser 121 and the second condenser 122 are configured by air-cooled heat exchangers, the first cooling fluid and the second cooling fluid may be air.

In the present embodiment, the second cooling fluid circulation device 22 includes the pump 22A, and the flow rate of the second cooling fluid supplied to the second condensation unit 122 can be adjusted by controlling the driving force of the pump 22A. This enables adjustment of the amount of cooling of the refrigerant in the second condensation portion 122.

As described above, the temperature-adjusting subject fluid circulation device 30 circulates the temperature-adjusting subject fluid that exchanges heat with the refrigerant in the evaporator 15. The temperature-adjusting fluid flowing through the temperature-adjusting fluid flowing device 30 may be a gas or a liquid.

When the fluid to be temperature-regulated is a gas, the fluid to be temperature-regulated circulation device 30 may be configured by a fan or the like. When the fluid to be temperature-adjusted is a liquid, the fluid distribution device 30 to be temperature-adjusted may be configured by a flow path for the liquid, a pump for circulating the liquid, and the like.

Further, the refrigeration circuit 10 is provided with a refrigerant temperature sensor 16 that detects the temperature of the refrigerant flowing out of the second condensation portion 122, and a refrigerant pressure sensor 17 that detects the pressure of the refrigerant flowing out of the second condensation portion 122. In detail, the refrigerant temperature sensor 16 detects the temperature of the refrigerant before flowing out of the second condensing portion 122 and into the sump 13. In other words, refrigerant temperature sensor 16 detects the temperature inside the pipe member connected to the outlet of second condensation unit 122. The refrigerant pressure sensor 17 detects the pressure of the refrigerant before flowing out of the second condensing portion 122 into the sump 13. In other words, the refrigerant pressure sensor 17 detects the pressure inside the pipe member connected to the outlet of the second condensation portion 122.

Further, the second cooling fluid circulation device 22 is provided with a cooling fluid temperature sensor 22B. The cooling fluid temperature sensor 22B detects the temperature of the second cooling fluid before the refrigerant is cooled in the second condensation portion 122. In other words, the cooling fluid temperature sensor 22B detects the temperature inside the portion of the piping member through which the second cooling fluid flows in the second cooling fluid circulation device 22 on the upstream side of the second condensation unit 122.

The controller 40 can control the operations of the respective parts of the refrigeration circuit 10 and the pump 22A of the second cooling fluid circulation device 22, and can acquire information from the various sensors 16, 17, and 22B. The controller 40 may be constituted by a computer having a CPU, ROM, RAM, or the like, for example, and controls the operations of the above-described respective units in accordance with a stored program.

The controller 40 includes a temperature information acquisition unit 41, a refrigerant state determination unit 42, an operation control unit 43, and an output unit 44.

The temperature information acquisition unit 41 acquires the temperature of the refrigerant flowing out of the second condensation portion 122 of the condenser 12 from the refrigerant temperature sensor 16, and acquires the temperature of the second cooling fluid before the second condensation portion 122 cools the refrigerant from the cooling fluid temperature sensor 22B.

The refrigerant state determination unit 42 determines that leakage or shortage of the refrigerant has occurred when the difference between the temperature of the refrigerant acquired by the temperature information acquisition unit 41 and the temperature of the second cooling fluid is greater than a threshold value stored in advance. Here, the temperature information acquisition unit 41 and the refrigerant state determination unit 42 constitute the refrigerant state detection device 40A.

The operation controller 43 controls the operations of the respective parts of the refrigeration circuit 10, the pump 22A of the second cooling fluid circulation device 22, and the like.

When the refrigerant state determination unit 42 determines that leakage or shortage of refrigerant has occurred, the output unit 44 displays a warning on a display device, not shown.

The flow of determining leakage or shortage of refrigerant by the refrigerant state detection device 40A in the present embodiment will be described below.

First, the configuration of the second condensation unit 122 and the state of the inside of the second condensation unit 122 during operation of the refrigeration circuit 10 will be described. Fig. 2A and 2B are schematic cross-sectional views of the second condensation portion 122 constituted by a plate heat exchanger. As shown in fig. 2A, the second condensation section 122 includes 2 or more plate members 122A stacked so that a flow path for the refrigerant or the second cooling fluid is formed between adjacent plate members 122A, and the 2 or more plate members 122A are alternately arranged in the stacking direction to form a flow path 122B for the refrigerant and a flow path 122C for the second cooling fluid.

A refrigerant inlet 122D and a refrigerant outlet 122E are connected to the plate member 122A located at one end in the stacking direction of 2 or more plate members 122A, and as indicated by white arrows, the refrigerant flows from the refrigerant inlet 122D to the refrigerant flow passage 122B and flows out from the refrigerant outlet 122E. The refrigerant inlet 122D and the refrigerant outlet 122E are disposed apart from each other in a direction orthogonal to the stacking direction, and in the present embodiment, the second condensation unit 122 is disposed such that the refrigerant inlet 122D is located above the refrigerant outlet 122E in the vertical direction. The refrigerant inlet 122D may be a part of a piping member connecting the first condensation unit 121 and the second condensation unit 122, or may be a member different from the piping member. Similarly, the refrigerant outlet portion 122E may be a part of a pipe member that connects the second condensation portion 122 to the sump 13, or may be a member different from the pipe member.

On the other hand, although not shown, a second cooling fluid inlet and a second cooling fluid outlet are also connected to the plate member 122A located at one end in the stacking direction, and as indicated by the hatched arrows, the second cooling fluid flows from the second cooling fluid inlet to the second cooling fluid flow passage 122C and flows out from the second cooling fluid outlet.

The second cooling fluid inlet and the second cooling fluid outlet are also disposed apart from each other in the direction orthogonal to the stacking direction, but the second cooling fluid inlet is provided on the same side as the refrigerant outlet 122E in the direction orthogonal to the stacking direction, and the second cooling fluid outlet is provided on the same side as the refrigerant inlet 122D in the direction orthogonal to the stacking direction. Therefore, in the present embodiment, the second cooling fluid outlet is located above the second cooling fluid inlet in the vertical direction. The second cooling fluid inlet portion may be provided on the same side as the refrigerant inlet portion 122D in the direction orthogonal to the stacking direction, and the second cooling fluid outlet portion may be provided on the same side as the refrigerant outlet portion 122E in the direction orthogonal to the stacking direction.

Further, symbol LM shown in fig. 2A indicates a liquid-state refrigerant condensed by the second cooling fluid and accumulated on the bottom side of the second condenser 122. In fig. 2A, the liquid surface height of the liquid refrigerant LM exceeds the upper end of the refrigerant outlet portion 122E, and the liquid refrigerant LM covers the refrigerant outlet portion 122E.

In the present embodiment, the operation control unit 43 of the controller 40 controls the pump 22A of the second cooling fluid circulation device 22 based on the pressure value of the refrigerant from the refrigerant pressure sensor 17, and thereby the refrigerant outlet portion 122E is covered with the liquid refrigerant LM.

Specifically, when the amount of cooling by the second cooling fluid circulation device 22 is small and the refrigerant is not sufficiently condensed, the liquid level of the refrigerant LM accumulated on the bottom side of the second condensation portion 122 does not exceed the upper end of the refrigerant outlet portion 122E, and the refrigerant in a gas state may enter the refrigerant outlet portion 122E. At this time, the pressure value of the refrigerant detected by the refrigerant pressure sensor 17 becomes larger than that in the case where the refrigerant outlet portion 122E is filled with the liquid refrigerant. Therefore, for example, when the refrigerant outlet portion 122E is filled with the liquid refrigerant, the pressure value detected by the refrigerant pressure sensor 17 is set to the threshold value, and the pump 22A of the second cooling fluid circulation device 22 is controlled based on the pressure value of the refrigerant from the refrigerant pressure sensor 17, whereby the refrigerant outlet portion 122E can be covered with the liquid refrigerant LM.

As described above, in a state where the refrigerant outlet portion 122E is covered with the liquid refrigerant LM, the difference between the temperature of the refrigerant detected by the refrigerant temperature sensor 16 and the temperature of the second cooling fluid before the refrigerant is cooled, which is detected by the cooling fluid temperature sensor 22B, is small, and preferably, the same temperature. In this way, when the difference between the temperature of the refrigerant detected by the refrigerant temperature sensor 16 and the temperature of the second cooling fluid detected by the cooling fluid temperature sensor 22B is a small value, it can be said that the normal operation is performed in which the refrigerant outlet portion 122E is covered with the liquid refrigerant LM, and the state is achieved in which an appropriate predetermined amount of refrigerant is filled in the refrigeration circuit 10. Such a predetermined amount of refrigerant can be determined by calculation and verification in consideration of the size of the refrigeration circuit 10 and the required refrigeration capacity.

On the other hand, although the control of the amount of cooling of the second cooling fluid circulation device 22 is performed such that the liquid refrigerant LM covers the refrigerant outlet portion 122E as described above, as shown in fig. 2B, when the liquid level of the refrigerant LM accumulated on the bottom side of the second condensation portion 122 does not exceed the upper end of the refrigerant outlet portion 122E, it can be regarded that the refrigerant in the refrigeration circuit 10 is in a state insufficient due to refrigerant leakage or the like. In this case, the refrigerant in a gas state enters the refrigerant outlet portion 122E, and the temperature of the refrigerant detected by the refrigerant temperature sensor 16 becomes higher than that in the case where the refrigerant outlet portion 122E is filled with the liquid refrigerant. As a result, the difference between the temperature of the refrigerant detected by the refrigerant temperature sensor 16 and the temperature of the second cooling fluid detected by the cooling fluid temperature sensor 22B becomes a large value.

The inventors of the present application have found that, as described above, in the case where the refrigerant leaks or runs short from the refrigeration circuit 10, the refrigerant state detection device 40A is employed, which determines that leakage or running short of the refrigerant has occurred when the difference between the temperature of the refrigerant detected by the refrigerant temperature sensor 16 and the temperature of the second cooling fluid detected by the cooling fluid temperature sensor 22B becomes large and the difference is larger than a threshold value stored in advance.

The inventors of the present application have found through intensive studies that the threshold for determining the leakage or shortage of the refrigerant is preferably 2 ℃ or more, more preferably 2 ℃ or more and 6 ℃ or less, and further preferably 2 ℃ or more and 4 ℃ or less. By setting the threshold value within such a range, the accuracy of determining leakage or shortage of the refrigerant is improved.

In the determination of the leakage or shortage of the refrigerant, a moving average value of the difference between the temperature of the refrigerant detected by the refrigerant temperature sensor 16 and the temperature of the second cooling fluid detected by the cooling fluid temperature sensor 22B may be calculated, and the moving average value may be compared with the threshold value. The moving average value may be calculated using the difference between the temperature of the refrigerant detected by the refrigerant temperature sensor 16 and the temperature of the second cooling fluid detected by the cooling fluid temperature sensor 22B at 3 or more detection points in the detection period of 3 seconds or more. When the moving average value is used, the influence of noise in the sensor is suppressed, and the determination accuracy can be improved.

As described above, in the present embodiment, the refrigerant state detection device 40A is provided in the refrigeration circuit 10. The refrigerant state detection device 40A further includes: a temperature information acquisition unit 41 that acquires the temperature of the refrigerant flowing out of the second condensation unit 122, and acquires the temperature of the second cooling fluid that cools the refrigerant in the second condensation unit 122 before cooling the refrigerant; and a refrigerant state determination unit 42 that determines that leakage or shortage of the refrigerant has occurred when the difference between the temperature of the refrigerant acquired by the temperature information acquisition unit 41 and the temperature of the second cooling fluid is greater than a threshold value stored in advance.

In such a refrigerant state detection device 40A, the number of parameters for determining leakage or shortage of refrigerant is suppressed. In addition, by using the temperature as a parameter for determination, the accuracy of determination of leakage or shortage of the refrigerant can be improved. That is, when the temperature of the refrigerant in the refrigeration circuit 10 is detected, detection of rapid fluctuation and noise is suppressed compared to the case of detecting the pressure.

Thus, according to the present embodiment, leakage or shortage of the refrigerant in the refrigeration circuit 10 can be detected easily and accurately.

(second embodiment)

Next, a temperature control system 2 according to a second embodiment will be described with reference to fig. 3. In the following description, only the points different from the first embodiment will be described.

As shown in fig. 3, in the present embodiment, the condenser 12 is constituted by one liquid-cooled heat exchanger. The cooling fluid flowing through the cooling fluid flowing device 20 is supplied to the condenser 12. The cooling fluid circulating device 20 includes a pump 22A for adjusting the flow rate of the cooling fluid and a cooling fluid temperature sensor 22B. The cooling fluid temperature sensor 22B detects the temperature of the cooling fluid before the cooling fluid cools the refrigerant in the condenser 12.

In the refrigerant state detection device 40A, the temperature information acquisition portion 41 acquires the temperature of the refrigerant flowing out of the condenser 12 from the refrigerant temperature sensor 16, and acquires the temperature of the cooling fluid before the refrigerant is cooled in the condenser 12 from the cooling fluid temperature sensor 22B. The refrigerant state determination unit 42 determines that leakage or shortage of the refrigerant has occurred when the difference between the temperature of the refrigerant acquired by the temperature information acquisition unit 41 and the temperature of the cooling fluid is greater than a threshold value stored in advance.

In the present embodiment, leakage or shortage of the refrigerant can be accurately detected with an extremely simple configuration.

(third embodiment)

Next, a temperature control system 3 according to a third embodiment will be described with reference to fig. 4. In the following description, only the points different from the first and second embodiments will be described.

In the present embodiment, the condenser 12 is constituted by one air-cooled heat exchanger. The condenser 12 is supplied with a cooling fluid, which is a gas that flows through the air cooling device 24 having a fan by driving the fan. The cooling fluid may be air. The cooling fluid temperature sensor 22B provided in the air cooling device 24 detects the temperature of the cooling fluid supplied to the condenser 12.

In the refrigerant state detection device 40A, the temperature information acquisition unit 41 acquires the temperature of the refrigerant flowing out of the condenser 12 from the refrigerant temperature sensor 16, and acquires the temperature of the cooling fluid, which is a gas before the refrigerant is cooled in the condenser 12, from the cooling fluid temperature sensor 22B. The refrigerant state determination unit 42 determines that leakage or shortage of the refrigerant has occurred when the difference between the temperature of the refrigerant acquired by the temperature information acquisition unit 41 and the temperature of the cooling fluid is greater than a threshold value stored in advance.

In the present embodiment, leakage or shortage of the refrigerant can be accurately detected with an extremely simple configuration.

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various modifications can be made to the above embodiments. For example, in each of the above embodiments, the receiver tank 13 is provided in the refrigeration circuit 10, but the receiver tank 13 may not be provided in the refrigeration circuit 10.