JP7210018B2 - Refrigerant state detection device, refrigerant state detection method, and temperature control system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a refrigerant state detection device, a refrigerant state detection method, and a temperature control system.

If the refrigerant leaks in the refrigerating circuit and the refrigerant becomes insufficient, problems such as a decrease in refrigerating capacity may occur.

Various techniques for detecting refrigerant leaks have been proposed in the past. For example, in Patent Document 1, compressor suction pressure, evaporator pressure, compressor discharge pressure, condenser pressure, compressor suction temperature, evaporator outlet temperature, compressor discharge temperature, condenser inlet temperature, etc. are detected, and these Techniques for detecting refrigerant leaks using detected values as parameters have been disclosed. Further, Patent Literature 2 discloses a technique of providing an indoor unit of an air conditioner with a refrigerant detection device for detecting refrigerant leaked to the outside.

JP 2016-121867 A WO2017/175300

However, the technique of Patent Literature 1 requires many sensors to detect pressure, temperature, etc., and many parameters are used to determine refrigerant leaks. In addition, in the technique of Patent Document 2, since the refrigerant detection device directly detects the leaked refrigerant to the outside, it is difficult to detect the leaked refrigerant at a position away from the refrigerant detection device, and the lack of refrigerant can be accurately detected. It is difficult to say that it can be detected in

In view of the above-described known techniques, the inventors of the present invention have made intensive studies to realize accurate detection of refrigerant leaks or refrigerant shortages as simply as possible. Then, the inventors found that the outlet temperature of the condenser becomes higher in a situation where the refrigerant is insufficient, compared to the outlet temperature when the refrigerant is not insufficient. And this phenomenon is that when the refrigerant is insufficient, the amount of condensation of the refrigerant condensed in the condenser becomes smaller than the planned or expected amount of condensation, and the high-temperature refrigerant in gaseous form flows downstream from the condenser outlet. It was found that it was caused by easy mixing with the piping on the side.

SUMMARY OF THE INVENTION The present invention has been made based on the above findings, and an object thereof is to provide a refrigerant state detection device, a refrigerant state detection method, and a temperature control system that can easily and accurately detect leakage or shortage of refrigerant in a refrigeration circuit. .

A refrigerant state detection device according to the present invention acquires the temperature of refrigerant flowing out of the condenser in a refrigeration circuit having a compressor, a condenser, an expansion valve, and an evaporator, and cools the refrigerant in the condenser. a temperature information acquisition unit that acquires the temperature of the cooling fluid before cooling the coolant; and a difference between the temperature of the coolant acquired by the temperature information acquisition unit and the temperature of the cooling fluid exceeds a prerecorded threshold. and a refrigerant state determination unit that determines that the refrigerant leaks or is in short supply when the refrigerant is inadequate.

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

The condenser has a first condensation section and a second condensation section for condensing the refrigerant flowing out of the first condensation section, and the temperature information acquisition section receives the refrigerant flowing out of the second condensation section. The temperature of the coolant and the temperature of the cooling fluid that cools the coolant in the second condensation section before cooling the coolant may be acquired.

A refrigerant state detection method according to the present invention acquires the temperature of refrigerant flowing out of the condenser in a refrigeration circuit having a compressor, a condenser, an expansion valve, and an evaporator, and cools the refrigerant in the condenser. a temperature information acquiring step of acquiring the temperature of the cooling fluid before cooling the coolant; and a difference between the temperature of the cooling fluid acquired in the temperature information acquiring step and the temperature of the cooling fluid exceeding a pre-recorded threshold value. and a refrigerant state determination step of determining that the refrigerant is leaking or running short when the refrigerant is in the state of being inadequate.

In the refrigerant state detection method according to the present invention, the temperature of the refrigerant flowing out of the condenser is obtained, and the temperature of the cooling fluid for cooling the refrigerant in the condenser is obtained before the refrigerant is cooled. in a case where the obtained temperature difference is equal to or less than the threshold, the charging step of charging the refrigerating circuit with a predetermined amount of the refrigerant that enables the operation of the refrigerating circuit, wherein the temperature after the charging step is The leakage or shortage of the refrigerant may be determined by the information acquisition step and the refrigerant state determination step.

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

A temperature control system according to the present invention includes a refrigeration circuit having a compressor, a condenser, an expansion valve, and an evaporator, and the refrigerant state detection device described above.

When the refrigerating circuit is filled with a predetermined amount of the refrigerant, the refrigerating circuit can perform operation such that the 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. may be configured to be

When the refrigerating circuit is filled with the predetermined amount of the refrigerant, the refrigerant is cooled by the condenser so that the refrigerant condensed by the condenser covers the outlet of the condenser. may be possible.

The temperature control system according to the present invention may further include a fluid flow device for causing the fluid whose temperature is controlled by the evaporator to flow.

ADVANTAGE OF THE INVENTION According to this invention, the leak or lack of the refrigerant|coolant in a refrigerating circuit can be detected simply and exactly.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows schematic structure of the temperature control system which concerns on the 1st Embodiment of this invention. FIG. 2 is a schematic cross-sectional view of a condenser provided in a refrigerating circuit of the temperature control system shown in FIG. 1; FIG. 2 is a schematic cross-sectional view of a condenser provided in a refrigerating circuit of the temperature control system shown in FIG. 1; It is a figure which shows schematic structure of the temperature control system which concerns on the 2nd Embodiment of this invention. It is a figure which shows schematic structure of the temperature control system which concerns on the 3rd Embodiment of this invention.

Each embodiment of the present invention will be described below.

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

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

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

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

Each of the first condenser section 121 and the second condenser section 122 is composed of a liquid-cooled heat exchanger, specifically a plate heat exchanger. However, the first condenser section 121 and the second condenser section 122 may be configured by air-cooled heat exchangers.

The receiver tank 13 receives and stores the refrigerant that has been condensed into a liquid by the condenser 12 , and the refrigerant stored in the receiver tank 13 flows to the expansion valve 14 side. The expansion valve 14 expands the refrigerant supplied from the receiver tank 13 to decompress the refrigerant, converts the refrigerant into a low-temperature, low-pressure liquid state or a gas-liquid mixed state, and supplies the refrigerant to the evaporator 15 . In the present embodiment, the evaporator 15 exchanges heat between the supplied refrigerant and the temperature-controlled fluid flowed by the temperature-controlled fluid circulation device 30 . The refrigerant that has exchanged heat with the fluid to be temperature-controlled flows out of the evaporator 15 into a low-temperature, low-pressure gas state and is compressed again by the compressor 11 .

The first cooling fluid circulation device 21 supplies the first cooling fluid to the first condensation section 121, and the second cooling fluid circulation device 22 supplies the second cooling fluid to the second condensation section 122. do. As described above, in the present embodiment, since the first condenser section 121 and the second condenser section 122 are configured by liquid-cooled heat exchangers, liquids are used as the first cooling fluid and the second cooling fluid. be done.

The liquid first and second cooling fluids may be water or other fluids. When the first condenser 121 and the second condenser 122 are 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 has a pump 22A, and by controlling the driving force of the pump 22A, the flow rate of the second cooling fluid supplied to the second condensation section 122 is controlled. Adjustable. Thereby, the cooling amount of the refrigerant in the second condenser section 122 can be adjusted.

The temperature control target fluid circulation device 30 causes the temperature control target fluid, which exchanges heat with the refrigerant in the evaporator 15 as described above, to flow. The temperature-controlled fluid flowed by the temperature-controlled fluid circulation device 30 may be gas or liquid.

When the temperature-controlled fluid is gas, the temperature-controlled fluid circulation device 30 may be configured by a fan or the like. When the temperature-controlled fluid is a liquid, the temperature-controlled fluid flow device 30 may be configured by a liquid flow path, a pump for flowing the liquid, or the like.

The refrigerating circuit 10 is also provided with a refrigerant temperature sensor 16 that detects the temperature of the refrigerant flowing out of the second condenser 122 and a refrigerant pressure sensor 17 that detects the pressure of the refrigerant flowing out of the second condenser 122. there is Specifically, the refrigerant temperature sensor 16 detects the temperature of the refrigerant that has flowed out of the second condenser 122 and before it flows into the receiver tank 13 . In other words, the refrigerant temperature sensor 16 detects the internal temperature of the piping member connected to the outlet of the second condenser 122 . The refrigerant pressure sensor 17 detects the pressure of the refrigerant that has flowed out of the second condensing section 122 and before it flows into the receiver tank 13 . In other words, the refrigerant pressure sensor 17 detects the temperature inside the piping member connected to the outlet of the second condenser 122 .

Further, the second cooling fluid circulation device 22 is provided with a cooling fluid temperature sensor 22B. Cooling fluid temperature sensor 22</b>B detects the temperature of the second cooling fluid before the refrigerant is cooled in second condenser 122 . In other words, the cooling fluid temperature sensor 22B detects the internal temperature of the upstream side portion of the second condensation section 122 in the piping member through which the second cooling fluid flows in the second cooling fluid circulation device 22. .

The controller 40 can control the operation of each part of the refrigerating circuit 10, the pump 22A of the second cooling fluid circulation device 22, etc., and can acquire information from the various sensors 16, 17, 22B described above. It is possible. The controller 40 may be configured by a computer including, for example, a CPU, ROM, RAM, etc., and may control the operations of the above sections according to a stored program.

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

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

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 exceeds a prerecorded threshold value, the refrigerant state determination unit 42 determines that leakage or shortage of the refrigerant has occurred. determine that there is Here, the temperature information acquisition unit 41 and the refrigerant state determination unit 42 constitute a refrigerant state detection device 40A.

The operation control unit 43 controls the operation of each part of the refrigeration circuit 10, the pump 22A of the second cooling fluid circulation device 22, and the like.

The output unit 44 displays a warning on a display device (not shown) when the refrigerant state determination unit 42 determines that the refrigerant is leaking or running short.

Hereinafter, the flow of determination of refrigerant leakage or shortage by the refrigerant state detection device 40A in the present embodiment will be described.

First, the structure of the second condenser section 122 and the state inside the second condenser section 122 during operation of the refrigeration circuit 10 will be described. 2A and 2B are schematic cross-sectional views of the second condenser section 122 configured with a plate heat exchanger. As shown in FIG. 2A, the second condensation section 122 is composed of a plurality of plates stacked such that a flow path for circulating the coolant or the second cooling fluid is formed between adjacent plate members 122A. A plurality of plate members 122A has a plurality of plate members 122A, in which coolant flow paths 122B and second cooling fluid flow paths 122C are alternately arranged in the stacking direction.

A plate member 122A positioned at one end in the stacking direction of the plurality of plate members 122A is connected to a coolant inlet portion 122D and a coolant outlet portion 122E. The coolant flows from the coolant inlet portion 122D to the coolant channel 122B and flows out from the coolant outlet portion 122E. Refrigerant inlet portion 122D and refrigerant outlet portion 122E are arranged apart from each other in a direction orthogonal to the stacking direction, and in the present embodiment, refrigerant inlet portion 122D is positioned above refrigerant outlet portion 122E in the vertical direction. The second condensing section 122 is arranged so as to. Refrigerant inlet portion 122D may be a part of a piping member that connects first condensation portion 121 and second condensation portion 122, or may be a member separate from this piping member. Similarly, the refrigerant outlet portion 122E may be a part of the pipe member that connects the second condenser portion 122 and the receiver tank 13, or may be a separate member from this 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 positioned at one end in the stacking direction. As shown, the second cooling fluid flows from the second cooling fluid inlet to the second cooling fluid channel 122C and out the second cooling fluid outlet.

The second cooling fluid inlet portion and the second cooling fluid outlet portion are also separated from each other in the direction perpendicular to the stacking direction, but the second cooling fluid inlet portion has the coolant outlet in the direction perpendicular to the stacking direction. The second cooling fluid outlet portion is provided on the same side as the portion 122E, and the second cooling fluid outlet portion is provided on the same side as the coolant inlet portion 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 coolant inlet portion 122D in the direction perpendicular to the stacking direction, and the second cooling fluid outlet portion may be provided on the same side as the coolant outlet portion 122E in the direction perpendicular to the stacking direction. They may be provided on the same side.

By the way, the symbol LM shown in FIG. 2A indicates the liquid refrigerant that is condensed by the second cooling fluid and accumulated on the bottom side of the second condensing section 122 . In FIG. 2A, the liquid level of the liquid coolant LM exceeds the upper end of the coolant outlet 122E, and the liquid coolant LM covers the coolant outlet 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 according to the pressure value of the refrigerant from the refrigerant pressure sensor 17, so that the liquid refrigerant LM is A state of covering the refrigerant outlet portion 122E is formed.

More specifically, when the cooling amount of the second cooling fluid flow 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 section 122 reaches the refrigerant outlet portion 122E. The gaseous refrigerant may enter the refrigerant outlet portion 122E without exceeding the upper end. At this time, the pressure value of the refrigerant detected by the refrigerant pressure sensor 17 becomes larger than when the refrigerant outlet portion 122E is filled with the liquid refrigerant. Therefore, for example, the pressure value detected by the refrigerant pressure sensor 17 when the refrigerant outlet portion 122E is filled with liquid refrigerant is defined as a threshold, and the second cooling is performed according to the pressure value of the refrigerant from the refrigerant pressure sensor 17. By controlling the pump 22A of the fluid communication device 22, it is possible to create a state in which the liquid coolant LM covers the coolant outlet 122E.

As described above, when the liquid refrigerant LM covers the refrigerant outlet portion 122E, 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 before the refrigerant is cooled. is a small value, ideally the same temperature. 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 small, the liquid refrigerant LM flows through the refrigerant outlet 122E. It can be said that the refrigerating circuit 10 is in a state in which a proper predetermined amount of refrigerant is charged in the refrigerating circuit 10 and the normal operation is performed. Such a predetermined amount of refrigerant can be determined through calculation and verification in consideration of the size of the refrigeration circuit 10 and the required refrigeration capacity.

On the other hand, although the cooling amount of the second cooling fluid circulation device 22 is controlled such that the liquid coolant LM covers the coolant outlet portion 122E as described above, FIG. As shown, when the liquid level of the refrigerant LM accumulated on the bottom side of the second condensing section 122 does not exceed the upper end of the refrigerant outlet section 122E, the refrigerant in the refrigerating circuit 10 is insufficient due to refrigerant leakage or the like. can be regarded as a state In this case, gaseous refrigerant enters the refrigerant outlet portion 122E, and the temperature of the refrigerant detected by the refrigerant temperature sensor 16 becomes higher than when the refrigerant outlet portion 122E is filled with 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.

As described above, when the refrigerant leaks or runs short from the refrigeration circuit 10, the inventors of the present invention have determined that 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 As a result, the refrigerant state detection device 40A is adopted, which determines that a refrigerant leak or shortage has occurred when this difference exceeds a pre-recorded threshold value.

Through intensive research, the inventors of the present invention have found that the threshold for determining the refrigerant leak or shortage is preferably 2°C or higher, more preferably 2°C or higher and 6°C or lower, and further preferably 2°C or higher and 4°C or lower. I found out. By setting the threshold within such a range, the accuracy of determination of refrigerant leakage or shortage is improved.

In determining whether the refrigerant leaks or is insufficient, the 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 is calculated. An average value may be compared to the threshold. The moving average value is 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 three or more detection points in a detection period of three seconds or more. may be calculated using When the moving average value is used, the judgment accuracy can be improved by suppressing the influence of noise in the sensor.

As described above, the refrigerant state detection device 40A is provided in the refrigeration circuit 10 in the present embodiment. Then, the refrigerant state detection device 40A obtains the temperature of the refrigerant flowing out of the second condenser 122, and obtains the temperature of the second cooling fluid that cools the refrigerant in the second condenser 122 before the refrigerant is cooled. When the difference between the temperature of the coolant acquired by the information acquisition unit 41 and the temperature of the second cooling fluid exceeds a pre-recorded threshold value, it is determined that there is a leakage or shortage of the coolant. and a refrigerant state determination unit 42 for determination.

In such a refrigerant state detection device 40A, the number of parameters used to determine refrigerant leakage or shortage is reduced. Further, by using the temperature as a parameter for determination, it is possible to improve the determination accuracy of refrigerant leakage or shortage. That is, when detecting the temperature of the refrigerant in the refrigerating circuit 10, detection of rapid fluctuations and noise is suppressed as compared with the case of detecting pressure.

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

(Second embodiment)
Next, a temperature control system 2 according to a second embodiment will be described with reference to FIG. In the following description only the differences with respect to the first embodiment will be described.

As shown in FIG. 3, in this embodiment, the condenser 12 is composed of one liquid-cooled heat exchanger. Cooling fluid is supplied to the condenser 12 by means of a cooling fluid circulation device 20 . The cooling fluid circulation device 20 has a pump 22A for adjusting the flow rate of the cooling fluid and a cooling fluid temperature sensor 22B. Cooling fluid temperature sensor 22 B senses the temperature of the cooling fluid before it cools the refrigerant in 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 also obtains the temperature of the cooling fluid before cooling the refrigerant in the condenser 12. obtained from the fluid temperature sensor 22B. When the difference between the temperature of the refrigerant acquired by the temperature information acquisition unit 41 and the temperature of the cooling fluid exceeds a prerecorded threshold value, the refrigerant state determination unit 42 determines that there is a leakage or shortage of the refrigerant. judge.

Also in the present embodiment, it is possible to accurately detect leakage or shortage of refrigerant with a very simple configuration.

(Third Embodiment)
Next, a temperature control system 3 according to a third embodiment will be described with reference to FIG. In the following description, only the differences with respect to the first and second embodiments will be described.

In this embodiment, the condenser 12 is composed of one air-cooled heat exchanger. The condenser 12 is supplied with a cooling fluid, which is a gas that is caused to flow by an air cooling device 24 having a fan when the fan is driven. The cooling fluid may be air. A 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 also obtains the temperature of the cooling fluid, which is a gas before cooling the refrigerant in the condenser 12. The temperature is obtained from the cooling fluid temperature sensor 22B. When the difference between the temperature of the refrigerant acquired by the temperature information acquisition unit 41 and the temperature of the cooling fluid exceeds a prerecorded threshold value, the refrigerant state determination unit 42 determines that there is a leakage or shortage of the refrigerant. judge.

Also in the present embodiment, it is possible to accurately detect leakage or shortage of refrigerant with a very simple configuration.

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

REFERENCE SIGNS LIST 1, 2, 3 Temperature control system 10 Refrigeration circuit 11 Compressor 12 Condenser 121 First condenser 122 Second condenser 122A Plate members 122B, 122C Flow path 122D Refrigerant inlet 122E Refrigerant outlet 13 Receiver tank 14 Expansion valve 15 Evaporator 16 Refrigerant temperature sensor 17 Refrigerant pressure sensor 20 Cooling fluid circulation device 21 First cooling fluid circulation device 22 Second cooling fluid Circulation device 22A Pump 22B Cooling fluid temperature sensor 24 Air cooling device 30 Temperature control target fluid circulation device 40 Controller 40A Refrigerant state detection device 41 Temperature information acquisition unit 42 Refrigerant state determination unit

Claims (10)

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 is obtained, and a cooling fluid for cooling the refrigerant in the condenser is obtained before the refrigerant is cooled. a temperature information acquisition unit that acquires temperature;
Refrigerant state determination for determining that a leak or shortage of the coolant occurs when a difference between the temperature of the coolant acquired by the temperature information acquisition unit and the temperature of the cooling fluid exceeds a pre-recorded threshold value and a refrigerant state detection device. 2. The refrigerant state detection device according to claim 1, wherein said condenser is a liquid-cooled heat exchanger, and said cooling fluid is liquid. The condenser has a first condensation section and a second condensation section for condensing the refrigerant flowing out from the first condensation section,
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. 3. The refrigerant state detection device according to claim 1 or 2. 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 is obtained, and a cooling fluid for cooling the refrigerant in the condenser is obtained before the refrigerant is cooled. a temperature information acquisition step of acquiring temperature;
Refrigerant state determination determining that a leak or shortage of the coolant occurs when a difference between the temperature of the coolant obtained in the temperature information obtaining step and the temperature of the cooling fluid exceeds a pre-recorded threshold value A refrigerant state detection method, comprising: When acquiring the temperature of the refrigerant flowing out of the condenser and acquiring the temperature of the cooling fluid that cools the refrigerant in the condenser before cooling the refrigerant, the difference between the acquired temperatures is further comprising a filling step of filling the refrigeration circuit with a predetermined amount of the refrigerant that enables operation of the refrigeration circuit that is equal to or less than the threshold;
5. The refrigerant state detection method according to claim 4, wherein leak or shortage of the refrigerant is determined by the temperature information acquisition step and the refrigerant state determination step performed after the filling step. 3. The refrigerating circuit cools the refrigerant in the condenser so that the refrigerant condensed in the condenser covers an outlet of the condenser when the refrigerating circuit is in operation after the charging step. 6. The refrigerant state detection method according to 4 or 5. a refrigeration circuit having a compressor, a condenser, an expansion valve and an evaporator;
A temperature control system comprising the refrigerant state detection device according to any one of claims 1 to 3. When the refrigerating circuit is filled with a predetermined amount of the refrigerant, the refrigerating circuit can perform operation such that the 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. 8. The temperature control system of claim 7, configured to: When the refrigerating circuit is filled with the predetermined amount of the refrigerant, the refrigerant is cooled by the condenser so that the refrigerant condensed by the condenser covers the outlet of the condenser. The temperature control system according to claim 8, wherein 10. The temperature control system according to any one of claims 7 to 9, further comprising a fluid circulation device for causing a fluid whose temperature is controlled by said evaporator to flow.

Images