JPH11211292A - Refrigerant leakage detector and refrigerant leakage detection method for freezer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To find out and cope with the leakage of a refrigerant in its early stages, by adjusting the temperature of a condensed refrigerant and the temperature of an evaporated refrigerant to fixed values, and detecting the leakage of the refrigerant from a freezing cycle by the temperature difference computed by a temperature difference computing means. SOLUTION: A condensed refrigerant temperature adjusting means 31 adjusts the temperature of a condensed refrigerant to a fixed value by the output signal of a condensed refrigerant temperature detector 5, and also an evaporated refrigerant temperature adjusting means 33 adjusts the temperature of an evaporated refrigerant to a fixed value by the output signal of an evaporated refrigerant temperature detector 6. Moreover, a temperature difference computing means 283 compares the output signal of a discharged refrigerant temperature detector 7 with the set value set in a storage means 29, and it detects the leakage of the refrigerant of a freezing cycle by the computed temperature difference. Hereby, the user can find out and cope with the leakage of the refrigerant in its early stage, and can prevent the abnormal drop of performance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant leak detecting device for a refrigeration system.

[0002]

2. Description of the Related Art Conventionally, a refrigerating apparatus has a compressor 101, a condenser 102, a throttle device 103, an evaporator 1 as shown in FIG.
04 are connected in a ring to form a refrigeration cycle. The operation of the refrigeration apparatus configured as described above will be described below. The high-temperature and high-pressure refrigerant vapor compressed by the compressor 101 is radiated by the condenser 102 to be condensed and liquefied.
Thereafter, the refrigerant is decompressed and expanded by the expansion device 103, becomes a low-temperature low-pressure refrigerant, absorbs heat by the evaporator 104, evaporates and evaporates, becomes low-temperature low-pressure refrigerant vapor, is compressed again by the compressor 101, and repeats a refrigeration cycle.

[0003]

However, in the above configuration, when the refrigerant leaks, there are the following problems. If the refrigerant leaks, the refrigerant in the refrigeration apparatus becomes insufficient, and the performance of the refrigerant decreases. Then, the discharge temperature of the compressor also increases. If the operation is performed for a long time in this state, the reliability of the refrigerator may be reduced, such as the burn-in of the motor of the compressor. Also,
A refrigeration system that has a controller that changes the opening degree, such as an electric expansion valve, and optimizes the discharge temperature of the compressor and superheat of the suctioned refrigerant, can operate even if the refrigerant leaks and runs short of refrigerant. In order to control the refrigeration cycle optimally by adjusting the opening of the refrigerant, it is difficult to find a refrigerant leak or a refrigerant shortage. Furthermore, even if the shortage of the refrigerant is found, it is not known how much the refrigerant has leaked. Therefore,
Since it is not possible to determine the amount of refrigerant to be replenished, the refrigerant must be charged again after all the refrigerant in the refrigeration cycle has been extracted. When a flammable refrigerant is used as the refrigerant, it is important from the viewpoint of safety to reliably detect the refrigerant leakage early. The present invention has been made to solve the problems of the conventional example described above, and has as its object to perform reliable detection of refrigerant leakage, or determine the amount of refrigerant leakage, and further display that the refrigerant has leaked or the amount of leakage. Things.

[0004]

According to a first aspect of the present invention, there is provided a refrigerant leakage detecting device for a refrigerating apparatus, comprising a compressor, a condenser, a throttle device, and an evaporator connected in a ring shape. A condensed refrigerant temperature detector for detecting the temperature of the refrigerant flowing through the condenser, a vaporized refrigerant temperature detector for detecting the temperature of the refrigerant flowing through the evaporator, and a refrigerant discharged from the compressor. A discharged refrigerant temperature detector for detecting a temperature; condensed refrigerant temperature adjusting means for adjusting the condensed refrigerant temperature to a constant value by an output signal of the condensed refrigerant temperature detector; and an evaporative refrigerant temperature by an output signal of the evaporative refrigerant temperature detector. Evaporating refrigerant temperature adjusting means for adjusting the condensed refrigerant temperature adjusting means and the condensed refrigerant temperature adjusting means for comparing the output signal of the discharged refrigerant temperature detector with a set value to calculate a temperature difference. Evaporative refrigerant By the time adjusting means adjusts the the condensing refrigerant temperature and the evaporating refrigerant temperature at a constant value, and detecting a refrigerant leak in the refrigeration cycle due to the temperature difference calculated by said temperature difference calculation means. According to a second aspect of the present invention, there is provided a refrigerant leak detecting apparatus for a refrigeration apparatus according to the first aspect, wherein the variable compressor has a variable rotational speed. A compressor rotation speed fixing means for fixing the rotation speed of the compressor. According to a third aspect of the present invention, there is provided a refrigerant leakage detection device for a refrigeration apparatus according to the first or second aspect, wherein the expansion device is a capillary tube. According to a fourth aspect of the present invention, there is provided a refrigerant leak detection device for a refrigeration system according to the second aspect, wherein the expansion device uses an expansion valve capable of adjusting a throttle opening as the expansion device. An expansion valve opening degree fixing means for fixing the opening degree at a constant value is provided. According to a fifth aspect of the present invention, there is provided a refrigerant leak detection device for a refrigeration apparatus according to any one of the first to fourth aspects, wherein the condensed refrigerant temperature adjusting means includes a rotation of a blower. Using a condenser blower rotation speed control means capable of continuously or intermittently changing the number, as the evaporative refrigerant temperature adjustment means, the rotation speed of the blower can be continuously or intermittently variable. It is characterized in that adjusting means is used. According to a sixth aspect of the present invention, there is provided a refrigerant leak detecting device for a refrigeration apparatus according to any one of the first to fourth aspects, wherein the condensed refrigerant temperature adjusting means includes a rotating pump. Continuous number,
Or, using an intermittently variable condenser pump rotation speed adjusting means, and as the evaporative refrigerant temperature adjusting means, using an evaporator pump rotation speed adjusting means capable of continuously or intermittently changing the pump rotation speed. It is characterized by the following. The refrigerant leakage detecting device for a refrigeration system according to claim 7 of the present invention is characterized by claim 1.
7. The refrigerant leak detecting device for a refrigeration system according to claim 6, wherein the condensed refrigerant temperature adjusted by the condensed refrigerant temperature adjusting means is set by a preset set value and the evaporative refrigerant temperature adjusting means. It is characterized in that it has a plurality of set values in which the evaporating refrigerant temperature is set in advance, and a set value selecting means for selecting an optimum set value in accordance with the operation state of the refrigerating apparatus. The refrigerant leakage detecting device for a refrigeration system according to claim 8 of the present invention is the fourth embodiment.
In the refrigerant leak detection device for a refrigerating device according to the present invention, the compressor has a plurality of preset values for the number of revolutions of the compressor and a plurality of preset values for the degree of opening of the expansion valve. It is characterized in that a set value selecting means for selecting an optimum set value in correspondence is provided. A refrigerant leakage detection device for a refrigeration apparatus according to claim 9 of the present invention is the refrigerant leakage detection apparatus for a refrigeration apparatus according to any one of claims 1 to 8, wherein the operation time of the refrigeration apparatus is integrated,
It is characterized in that an automatic refrigerant leak detecting means for detecting a refrigerant leak at regular intervals is provided. The refrigerant leak detecting device for a refrigeration system according to claim 10 of the present invention is configured as described in claims 1 to 8.
The refrigerant leakage detection device for a refrigeration system according to any one of the above, further comprising an automatic refrigerant leakage detection unit that detects refrigerant leakage when the operation of the refrigeration system is started. A refrigerant leakage detection device for a refrigeration system according to claim 11 of the present invention is the refrigerant leakage detection device for a refrigeration system according to any one of claims 1 to 8, wherein after a lapse of a predetermined time from the start of operation of the refrigeration system. An automatic refrigerant leak detecting means for detecting refrigerant leakage is provided. The refrigerant leak detecting device for a refrigeration system according to claim 12 of the present invention is configured as described in claims 1 to 11.
The refrigerant leak detecting device for a refrigeration system according to any one of the above, further comprising a manual refrigerant leak detecting means capable of detecting the refrigerant leak at an arbitrary timing. The refrigerant leak detecting device for a refrigeration system according to claim 13 of the present invention is characterized by claim 1.
The refrigerant leakage detection device for a refrigeration apparatus according to any one of claims 12 to 14, further comprising: refrigerant leakage display means for displaying that a refrigerant leakage has occurred in the refrigeration apparatus when the refrigerant leakage is detected. I do. A refrigerant leakage detection device for a refrigeration apparatus according to claim 14 of the present invention is the refrigerant leakage detection apparatus for a refrigeration apparatus according to any one of claims 1 to 13, wherein the refrigerant is discharged when the refrigerant leakage is detected. The output signal of the temperature detector is compared with a set value, the amount of refrigerant leakage is determined based on the calculated temperature difference, and refrigerant leakage display means for displaying the amount of refrigerant to be refilled to the refrigeration apparatus is provided. . A refrigerant leak detection device for a refrigeration system according to claim 15 of the present invention is the refrigerant leakage detection device for a refrigeration system according to any one of claims 1 to 14, wherein a flammable refrigerant is used as a refrigerant to reduce refrigerant leakage. When detected, the output signal of the discharged refrigerant temperature detector is compared with a set value, the amount of refrigerant leakage is determined from the calculated temperature difference, and when a predetermined amount or more of refrigerant leakage occurs, a caution signal is issued. It is characterized by providing a refrigerant leak display means for displaying. Claim 16 of the present invention
The refrigerant leakage detection method for a refrigeration apparatus described above comprises a refrigeration cycle in which a compressor, a condenser, a throttle device, and an evaporator are connected in a ring, and the condensing refrigerant temperature of the condenser and the evaporating refrigerant temperature of the evaporator. After adjusting to a fixed value set in advance, detecting the refrigerant discharge temperature of the compressor, and detecting refrigerant leakage of the refrigeration cycle by the temperature difference calculated by the detected discharge refrigerant temperature and the set value. Features. A refrigerant leak detection method for a refrigeration system according to claim 17 of the present invention comprises connecting a compressor having a variable number of revolutions, a condenser, an expansion valve capable of adjusting a throttle opening, and an evaporator in a ring shape. A refrigeration cycle, and after fixing the number of rotations of the compressor and the opening degree of the expansion valve to a predetermined constant value, the condensing refrigerant temperature of the condenser and the evaporating refrigerant temperature of the evaporator are determined in advance. Adjusting to a set constant value, thereafter detecting the refrigerant discharge temperature of the compressor, and detecting refrigerant leakage of the refrigeration cycle by a temperature difference calculated by the detected discharge refrigerant temperature and the set value. . The refrigerant leak detection method for a refrigeration apparatus according to claim 18 of the present invention,
After forming a refrigeration cycle by connecting the compressor, the condenser, the expansion device, and the evaporator in a ring, after adjusting the condensed refrigerant temperature of the condenser and the evaporative refrigerant temperature of the evaporator to a predetermined constant value. Detecting the temperature of the refrigerant discharged from the compressor,
The amount of refrigerant leakage is determined based on the detected refrigerant temperature and the temperature difference calculated based on the set value, and a caution signal due to the amount of refrigerant leakage, the amount of refrigerant to be replenished, or a certain amount of refrigerant leakage is displayed on the refrigeration system. It is characterized by the following. According to a refrigerant leak detection method for a refrigeration system according to claim 19 of the present invention, a compressor having a variable number of revolutions, a condenser, an expansion valve capable of adjusting a throttle opening, and an evaporator are connected in a ring shape. A refrigeration cycle, and after fixing the number of revolutions of the compressor and the opening of the expansion valve to a predetermined constant value, the condensing refrigerant temperature of the condenser and the evaporating refrigerant temperature of the evaporator are determined in advance. Adjust to a set constant value, then detect the refrigerant discharge temperature of the compressor, determine the refrigerant leakage amount by the detected discharge refrigerant temperature and the temperature difference calculated by the set value,
The refrigerating apparatus displays a refrigerant leakage amount, a refrigerant amount to be supplemented, or a warning signal due to a refrigerant leakage of a certain amount or more.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A refrigerant leak detecting device of a refrigeration system according to a first embodiment of the present invention has a condensed refrigerant temperature adjusting means and an evaporating refrigerant temperature adjusting means for controlling the condensed refrigerant temperature and the evaporative refrigerant temperature to a fixed value. And a temperature difference calculating means for calculating a temperature difference by comparing an output signal of the discharged refrigerant temperature detector with a set value to detect refrigerant leakage of the refrigeration cycle. In the first embodiment of the present invention, when the amount of the charged refrigerant is constant, if the temperature of the condensed refrigerant flowing through the condenser and the temperature of the evaporated refrigerant flowing through the evaporator are determined, the temperature of the discharged refrigerant becomes constant, Fluctuates, the discharged refrigerant temperature changes. Therefore, by adjusting the temperature of the condensed refrigerant flowing through the condenser and the temperature of the vaporized refrigerant flowing through the evaporator to be constant, it is possible to determine the temperature of the discharged refrigerant under an appropriate amount of refrigerant. Therefore, the discharge refrigerant temperature under the appropriate refrigerant amount is set as a set value, and is compared with the output signal of the discharge refrigerant temperature detector. If it is higher than the value, it can be determined that the refrigerant is leaking.

[0006] The second embodiment of the present invention, even when a compressor whose rotation speed can be varied is used as the compressor,
This is to accurately detect refrigerant leakage in the first embodiment. In other words, a compressor having a variable rotation speed is provided with a compressor rotation speed fixing means for fixing the rotation speed of the compressor to a constant value. By fixing the rotational speed of the compressor to a constant value in this way, the temperature of the discharged refrigerant under an appropriate refrigerant amount is determined from the temperature of the condensed refrigerant flowing through the condenser and the temperature of the evaporated refrigerant flowing through the evaporator at that rotational speed. can do. In the third embodiment of the present invention, the expansion device is a capillary tube. In this way, by using a capillary tube with a constant throttle amount,
From the temperature of the condensed refrigerant flowing through the condenser and the temperature of the evaporated refrigerant flowing through the evaporator, it is possible to determine the temperature of the discharged refrigerant under an appropriate amount of refrigerant.

The fourth embodiment of the present invention accurately detects refrigerant leakage even when an expansion valve whose opening degree is adjustable is used as the expansion device. That is, an expansion valve having an adjustable throttle opening is provided with expansion valve opening fixing means for fixing the opening of the expansion valve to a constant value. By fixing the opening of the expansion valve to a constant value in this manner, the temperature of the discharged refrigerant under an appropriate amount of refrigerant is determined from the temperature of the condensed refrigerant flowing through the condenser and the temperature of the evaporated refrigerant flowing through the evaporator at that opening. can do. In the fifth embodiment of the present invention, a condenser blower rotational speed adjusting means is used as the condensing refrigerant temperature adjusting means, and an evaporator blower rotational speed adjusting means is used as the evaporative refrigerant temperature adjusting means. A fifth embodiment of the present invention provides a medium heated by a condenser,
When the medium cooled by the evaporator is a gas such as air, the number of rotations of the condenser blower and the evaporator blower is continuously increased,
Alternatively, the refrigerant temperature can be adjusted to be a constant value by intermittently changing the temperature.

According to a sixth embodiment of the present invention, a condenser pump speed adjusting means is used as a condensing refrigerant temperature adjusting means,
The evaporator pump rotation speed adjusting means is used as the evaporating refrigerant temperature adjusting means. According to a sixth embodiment of the present invention,
When the medium heated by the condenser and the medium cooled by the evaporator are liquids such as water, the refrigerant temperature is continuously or intermittently varied by changing the rotation speed of the condenser pump and the evaporator pump. Can be adjusted to a constant value.
The seventh embodiment of the present invention has a plurality of set values for the condensed refrigerant temperature adjusted by the condensed refrigerant temperature adjuster and the evaporative refrigerant temperature adjusted by the evaporative refrigerant temperature adjuster, and operates the refrigeration apparatus. There is provided a set value selecting means for selecting an optimum set value corresponding to a state. By providing a plurality of setting values in this way, when adjusting the condensing refrigerant temperature and the evaporating refrigerant temperature to constant values, it is possible to select a setting value having a small difference from the refrigerant temperature at the time of refrigerant leak detection, so that It can be efficiently adjusted to a constant value.

An eighth embodiment of the present invention has a plurality of set values in which the number of revolutions of the compressor is set in advance and a set value in which the degree of opening of the expansion valve is set in advance. There is provided a set value selecting means for selecting an optimum set value corresponding to a state. By providing a plurality of set values in this way, when the rotational speed of the compressor and the opening of the expansion valve are fixed at fixed values, a set value corresponding to the operating state can be selected, so that the refrigerant temperature can be shortened. It can be efficiently adjusted to a constant value over time. In the ninth embodiment of the present invention, refrigerant leak detection is automatically performed at regular intervals. Performing the refrigerant leak detection regularly in this manner enables early detection of the refrigerant leak.

[0010] In a tenth embodiment of the present invention, refrigerant leakage detection is automatically performed at the start of operation of a refrigeration system. By performing the refrigerant leak detection at the start of the operation as described above, it is possible to prevent the compressor from being damaged when the operation is performed in the state of the refrigerant shortage. Also, since it is easier for the refrigerant to leak during operation than when the operation is stopped,
By detecting at an early stage of the operation, the amount of the leaked refrigerant can be minimized, and the safety particularly when a flammable refrigerant is used can be enhanced. In the eleventh embodiment of the present invention, the detection of the refrigerant leak is automatically performed after a lapse of a predetermined time from the start of the operation of the refrigeration apparatus. As described above, by performing the detection after the elapse of a predetermined time from the start of the operation, the refrigerant leakage can be detected in the stable operation state, so that the refrigerant leakage can be reliably detected.

In a twelfth embodiment of the present invention, refrigerant leakage can be manually detected. Since the refrigerant leakage can be manually detected in this way, it is possible to reliably detect the refrigerant leakage or the refrigerant shortage at the time of installing the refrigeration apparatus, at the time of trial operation, at the time of service, or the like. In the thirteenth embodiment of the present invention, when refrigerant leakage is detected, it is displayed that refrigerant leakage has occurred in the refrigerating apparatus. By providing such a refrigerant leakage display means, it is possible to reliably notify the leakage of the refrigerant, without operating at an abnormally high discharge temperature, not only preventing an abnormal decrease in performance, but also improving the reliability of the refrigeration cycle parts. Can be prevented from decreasing. Further, it is possible to reliably avoid the danger caused by refrigerant leakage when a flammable refrigerant is used.

According to a fourteenth embodiment of the present invention, when a refrigerant leak is detected, the output signal of the discharged refrigerant temperature detector is compared with a set value, the amount of the refrigerant leak is determined from the calculated temperature difference, and the refrigerant is refrigerated. It indicates the amount of refrigerant to be refilled into the device. By providing such a refrigerant leak display means, it is possible to replenish the refrigerant at the time of service without any excess or shortage, it is possible to maintain an optimal refrigeration cycle, not only to prevent performance deterioration, but also to improve the reliability of the refrigeration cycle parts. Can be prevented from decreasing. The fifteenth embodiment of the present invention uses a flammable refrigerant as a refrigerant and, when a refrigerant leakage is detected, compares an output signal of a discharged refrigerant temperature detector with a set value, and calculates a refrigerant leakage amount based on the calculated temperature difference. Is determined, and a warning signal is displayed when refrigerant leakage occurs for a predetermined amount or more. By providing such a refrigerant leakage display means, when a refrigerant leakage of a certain amount or more occurs, a warning signal is displayed, so that the user is alerted, and the flammable refrigerant is ignited and a fire or explosion is generated. Can be prevented.

A refrigerant leak detecting method according to a sixteenth embodiment of the present invention comprises the steps of: adjusting the condensed refrigerant temperature of the condenser and the evaporative refrigerant temperature of the evaporator to predetermined preset values;
The refrigerant discharge temperature of the compressor is detected, and a refrigerant leak of the refrigeration cycle is detected based on a temperature difference calculated from the detected refrigerant discharge temperature and a set value. in this way,
By adjusting the temperature of the condensing refrigerant flowing through the condenser and the temperature of the evaporating refrigerant flowing through the evaporator to constant values, the temperature of the discharged refrigerant under an appropriate amount of refrigerant can be determined. Therefore, the discharge refrigerant temperature under the appropriate refrigerant amount is set as a set value, and is compared with the output signal of the discharge refrigerant temperature detector. If it is higher than the value, it can be determined that the refrigerant is leaking.

A refrigerant leak detecting method according to a seventeenth embodiment of the present invention is directed to a refrigeration cycle using a compressor whose rotation speed is variable and an expansion valve whose throttle opening is adjustable.
After fixing the number of rotations of the compressor and the opening of the expansion valve to a predetermined constant value, the condensing refrigerant temperature of the condenser and the evaporating refrigerant temperature of the evaporator are adjusted to the predetermined constant values, and then the compression is performed. The temperature of refrigerant discharged from the machine is detected, and refrigerant leakage of the refrigeration cycle is detected based on a temperature difference calculated based on the detected refrigerant temperature and a set value.
By fixing the rotation speed of the compressor and the opening of the expansion valve to fixed values in this manner, the appropriate amount of refrigerant can be determined from the temperature of the condensed refrigerant flowing through the condenser and the temperature of the evaporated refrigerant flowing through the evaporator at that rotation speed and opening. Below, the temperature of the discharged refrigerant can be determined.

In the refrigerant leak detecting method according to an eighteenth embodiment of the present invention, after the condensing refrigerant temperature of the condenser and the evaporating refrigerant temperature of the evaporator are adjusted to predetermined constant values,
The temperature of the refrigerant discharged from the compressor is detected, and the amount of refrigerant leakage is determined based on a temperature difference calculated from the detected temperature of the discharged refrigerant and the set value. The caution signal due to the refrigerant leakage is displayed. The refrigerant leakage amount can be determined based on the temperature difference calculated from the discharge refrigerant temperature detected by such a method and the set value. Therefore, it is possible to display a warning signal due to the refrigerant leakage amount, the refrigerant amount to be replenished, or the refrigerant leakage of a certain amount or more, the refrigerant can be replenished without excess or shortage at the time of service, and the optimal refrigeration cycle can be maintained. Not only prevents performance degradation, but also prevents the reliability of refrigeration cycle components from deteriorating, and also alerts users to prevent flammable refrigerants from igniting and causing fires and explosions. be able to.

A refrigerant leak detecting method according to a nineteenth embodiment of the present invention is directed to a refrigeration cycle using a compressor whose rotation speed can be varied and an expansion valve whose throttle opening can be adjusted.
After fixing the rotation speed of the compressor and the opening degree of the expansion valve to a predetermined constant value, the condensing refrigerant temperature of the condenser and the evaporating refrigerant temperature of the evaporator are adjusted to a predetermined constant value. The detected refrigerant refrigerant temperature is detected, the refrigerant leakage amount is determined by the temperature difference calculated from the detected refrigerant discharge temperature and the set value, and the refrigerant leakage amount to the refrigerating device, the refrigerant amount to be replenished, or a certain amount or more. A warning signal due to refrigerant leakage is displayed. The refrigerant leakage amount can be determined based on the temperature difference calculated from the discharge refrigerant temperature detected by such a method and the set value. Therefore, it is possible to display a warning signal due to the refrigerant leakage amount, the refrigerant amount to be replenished, or the refrigerant leakage of a certain amount or more, the refrigerant can be replenished without excess or shortage at the time of service, and the optimal refrigeration cycle can be maintained. Not only prevents performance degradation, but also prevents the reliability of refrigeration cycle components from deteriorating, and also alerts users to prevent flammable refrigerants from igniting and causing fires and explosions. be able to.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a refrigeration cycle diagram of a refrigeration apparatus according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a compressor, 2 denotes a condenser, 3 denotes a capillary tube, and 4 denotes an evaporator, which are sequentially connected in a ring to constitute a refrigeration cycle. 5 is a condensed refrigerant temperature detector for detecting the temperature of the refrigerant flowing through the condenser 2, 6 is the evaporative refrigerant temperature detector for detecting the temperature of the refrigerant flowing through the evaporator 4, and 7 is the refrigerant temperature discharged from the compressor 1. A discharged refrigerant temperature detector, 8 is a condenser blower that sends a non-heating medium such as air to the condenser 2, and 9 is an evaporator blower that sends a non-cooling medium such as air to the evaporator 4. FIG. 2 is an electric circuit diagram showing an electric connection of the refrigeration apparatus shown in FIG. In the figure, 5 is a condensed refrigerant temperature detector for detecting the temperature of the condensed refrigerant flowing through the condenser 2, and 6 is an evaporator 4
Refrigerant temperature detector for detecting the temperature of refrigerant flowing through
Is a discharge refrigerant temperature detector for detecting the discharge refrigerant temperature of the compressor 1. 20 is an operation switch, 21, 22, and 23 are A
/ D converter, 24 is a microcomputer (hereinafter LS)
I) and has an input circuit 27, a CPU 28, a memory 29, and output circuits 30, 32, and 34. The output of the condensed refrigerant temperature detector 5 is input to the input circuit 27 via the A / D converter 21, and the output of the evaporative refrigerant temperature detector 6 is supplied to the input circuit 27.
The output of the discharge temperature detector 7 via the / D converter 22 is
It is input via the A / D converter 23. 31 is a condenser blower rotation speed control device that can continuously or stepwise change the rotation speed of the condenser blower 8, and 33 is an evaporator blower rotation that can continuously or stepwise change the rotation speed of the evaporator blower 9. The condenser blower 8, the evaporator blower 9, and the display 35 are operated by the output of the output circuits 30, 32, 34 by the numerical controller.

Referring now to the block diagram shown in FIG. 3 and the electric circuit diagram shown in FIG. 2, the condensed refrigerant temperature detector 5, the evaporated refrigerant temperature detector 6, and the discharged refrigerant temperature detector 7 shown in FIG. The condensed refrigerant temperature detecting means 5, the evaporating refrigerant temperature detecting means 6, the discharged refrigerant temperature detecting means 7, and the memory 29 of FIG. 2 are storage means for storing the set values of the condensing temperature, the evaporating temperature, and the discharging temperature of FIG. Equivalent to 29. FIG.
The CPU 28 selects one of the set values in the storage unit 29 based on output signals from the condensed refrigerant temperature detector 5, the evaporative refrigerant temperature detector 6, and the discharged refrigerant temperature detector 7.
81, condensed refrigerant temperature detector 5, evaporative refrigerant temperature detector 6
Means 282 that compares the output signal of the discharged refrigerant temperature detector 7 with the set value and outputs a control signal, and compares the output signal of the discharged refrigerant temperature detector 7 with the set value to calculate the temperature difference. It corresponds to the calculating means 283 and the refrigerant leak detecting means 284 for detecting the refrigerant leak of the refrigerating apparatus based on the temperature difference calculated by the temperature difference calculating means 283. The condenser blower rotation speed control device 31 and the evaporator blower rotation speed control device 33 in FIG. 2 adjust the condensed refrigerant temperature to a set value based on the output signal generated from the comparing means 282 in FIG. It corresponds to the means 31 and the evaporative refrigerant temperature adjusting means 33 for adjusting the evaporative refrigerant temperature to a set value. The refrigerant leakage display device 35 in FIG. 2 corresponds to a display unit 35 that displays the occurrence of refrigerant leakage based on an output signal generated by the refrigerant leakage detection unit 284.

In the above configuration, the configuration and operation of the control circuit during operation of the refrigeration system will be described with reference to FIG. FIG. 4 shows LS
It is a flowchart which shows the program of the refrigerator stored in the memory 29 of I24. Operation switch 20 ON
When the signal is issued, the operation of the refrigeration apparatus starts, and the refrigeration apparatus is operated in a normal operation mode. Then, step 40 (S in the figure)
Indicated as 40. Hereinafter, the same display is used. ), The timer is counted, and after a certain period of time has elapsed since the start of operation, the discharge temperature is stabilized and the refrigeration cycle is stabilized. After that, the mode automatically shifts to the refrigerant leak detection mode, and step 41 is executed to execute the refrigerant in the condenser 2. The temperature Tc and the refrigerant temperature Te of the evaporator 4 are detected.
Condensation temperature Tc1, Tc2, evaporation temperature Te1, Te2,
One set value (here, a first set value) for the discharge temperature Tcomp1 is selected. In step 43, the refrigerant temperature Tc of the condenser 2 is detected, and in step 44, a comparison operation with the set temperature Tc1 (for example, 40 ° C.) is performed, and Tc ≧
If Tc1, the process proceeds to step 46 with a determination of “YES”. If Tc <Tc1, the process proceeds to step 45 with a determination of “NO”, and sends a control signal to the condenser blower rotation speed control device 31 to increase Tc. Then, the rotation speed of the condenser blower 8 is reduced, and the process returns to step 43. In step 46, a comparison operation with the set temperature Tc2 (for example, 43 ° C.) is performed, and if Tc ≦ Tc2, the process proceeds to step 48 with a determination of “YES”. If Tc> Tc2, the determination of “NO” proceeds to step 47, where a control signal is output to the condenser blower rotation speed control device 31 so as to reduce Tc, the rotation speed of the condenser blower 8 is increased, and step 43 is performed. Go back.
Next, in step 48, the refrigerant temperature Te of the evaporator 4 is detected, and in step 49, Te and the set temperature Te1 (for example, 10
° C), and if Te ≧ Te1, “YE
The process proceeds to step 51 by the determination of “S”, and Te <Te1
If so, the process proceeds to step 50 with a determination of “NO”, and T
A control signal is output to the evaporator blower rotation speed control device 33 so as to increase e, the rotation speed of the evaporator blower 9 is increased, and the process returns to step 48. If Te> Te2 in step 51, the process proceeds to step 53 with a determination of "YES". If Te> Te2 in step 51, the process proceeds to step 52 with a determination of "NO", and outputs a control signal to the evaporator blower rotation speed control device 33 so as to reduce Te, thereby lowering the rotation speed of the evaporator blower 9. Return to step 48.

As described above, the refrigerant temperature Tc of the condenser 2 and the refrigerant temperature Te of the evaporator 4 are controlled to the set values, and when the operation is continued, if the refrigerant amount is an appropriate amount, the discharge temperature of the compressor 1 Tcomp is a value close to the set value Tcomp1. When a refrigerant leak occurs and the refrigerant becomes insufficient, the discharge temperature Tcomp becomes higher than the set value Tcomp1. Therefore, in step 53, Tcomp
If ≤Tcomp1, a "YES" determination results in step 5
Proceed to step 4 to determine that the operation is normal, and return to the normal operation mode. When a refrigerant leak occurs and the refrigerant becomes insufficient, the discharge temperature Tcomp becomes higher than the set value Tcomp1, and in step 53, Tcomp> T
When the determination is "NO", the process proceeds to step 55, where it is determined that "the refrigerant is insufficient", an abnormal signal is displayed on the refrigerant leak indicator 35 (step 56), and the operation returns to the normal operation mode. In this way, the refrigerant leak is automatically detected, and the abnormality of the refrigerator can be found at an early stage, so that the operation is not performed at an abnormally high discharge temperature, and not only is the abnormal performance lowered, The reliability of the refrigeration cycle components can be prevented from being reduced. It should be noted that the storage circuit has a plurality of set values for the condensation temperature, the evaporation temperature, and the discharge temperature selected by the selection means built in the LSI 24 in step 42, and the refrigerant temperature Tc of the condenser 2 detected in step 41 and the evaporator 4
If a set value closer to the refrigerant temperature Te is selected, the refrigeration cycle can be controlled in a shorter time, and refrigerant leakage can be detected in a shorter time. Further, by providing an automatic refrigerant leak detecting means for accumulating the operation time of the refrigerating apparatus and automatically detecting the refrigerant leakage at a predetermined time interval, the refrigerant leakage can be detected at an early stage.

(Embodiment 2) FIG. 5 is a refrigeration cycle diagram of a refrigeration apparatus according to a second embodiment of the present invention. In the figure, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The same applies to the following drawings.
In the figure, reference numeral 11 denotes a compressor whose rotation speed can be varied;
Is an expansion valve whose opening degree can be adjusted. FIG. 6 is an electric circuit diagram showing the electric connection of the refrigeration apparatus shown in FIG. In the figure,
Reference numeral 37 denotes a compressor rotation speed control device that can change the rotation speed of the compressor 11, and 39 denotes an expansion valve drive device that can change the opening of the expansion valve 12.
1. The expansion valve 12 is operated. Here, the block diagram shown in FIG. 7 and the electric circuit diagram shown in FIG. 6 will be described.
The compressor speed control device 37 and the expansion valve drive device 39 of
7 corresponds to the compressor rotation speed fixing means 37 and the expansion valve opening degree fixing means 39 in FIG.

In the above configuration, the configuration and operation of the control circuit during operation of the refrigeration system will be described with reference to FIG. FIG. 8 shows LS
It is a flowchart which shows the program of the refrigerator stored in the memory 29 of I24. Operation switch 20 ON
When the signal is issued, the operation of the refrigeration apparatus starts, and the refrigeration apparatus is operated in a normal operation mode. Then, the timer is counted in step 60, a predetermined time has elapsed after the start of operation, and the refrigeration cycle has become stable. After that, the mode automatically shifts to the refrigerant leakage detection mode, and step 61 is executed to execute the refrigerant temperature Tc of the condenser 2. , The refrigerant temperature Te of the evaporator 4 is detected.
In step 2, the selector 281 sets one set value (here, the first set value and the first set value) for the rotation speed Rc of the compressor 11 in the storage circuit, the opening degree Pex of the expansion valve 12, the condensation temperature Tc1, the evaporation temperature Te1, and the discharge temperature Tcomp1. Is selected. At step 63, the compressor rotation speed control device 3 is output from the output circuit 36.
7 to control the rotation speed of the compressor 11 to a set value Rc.
And the expansion circuit drive 39
To fix the opening of the expansion valve 12 to the set value Pex. In step 64, the refrigerant temperature Tc of the condenser 2 is detected, and in step 65, the set temperature Tc1 (for example, 40 ° C.)
Is performed, and if Tc ≧ Tc1, “YES”
If Tc <Tc1, the process proceeds to step 66 with the determination of “NO”, and Tc
The control signal is output to the condenser blower rotation speed control device 31 so as to increase the rotation speed of the condenser blower 8, the rotation speed of the condenser blower 8 is reduced, and the process returns to step 64. If Tc ≦ Tc2 in step 67, the process proceeds to step 69 with a determination of “YES”. Tc>
If it is Tc2, the process proceeds to step 68 with the determination of "NO", outputs a control signal to the condenser blower rotation speed control device 31 so as to lower Tc, increases the rotation speed of the condenser blower 8, and returns to step 64. . Next, in step 69, the refrigerant temperature Te of the evaporator 4 is detected, and in step 70, a comparison operation between Te and a set temperature Te1 (for example, 10 ° C.) is performed.
If Te ≧ Te1, the process proceeds to step 72 with a determination of “YES”. If Te <Te1, the process proceeds to step 71 with a determination of “NO”, and the evaporator blower rotation speed control device 33 is controlled to increase Te. A signal is output, the number of revolutions of the evaporator blower 9 is increased, and the process returns to step 69. If Te ≦ Te2 in step 72, the process proceeds to step 74 with a determination of “YES”. In step 72, Te> Te2
If so, the process proceeds to step 73 with a determination of “NO”,
Evaporator blower rotation speed control device 33 to lower Te
And output a control signal to reduce the number of revolutions of the evaporator blower 9,
Return to step 69. As described above, the refrigerant temperature Tc of the condenser 2 and the refrigerant temperature Te of the evaporator 4 are controlled to the set values,
When the operation is continued, if the refrigerant amount is an appropriate amount, the compressor 1
1 is a value close to the set value Tcomp1.
When a refrigerant leak occurs and the refrigerant becomes insufficient, the discharge temperature T
comp becomes higher than the set value Tcomp1. Therefore, if Tcomp ≦ Tcomp1 in step 74, the process proceeds to step 75 based on the determination of “YES” and is determined to be “normal”, and returns to the normal operation mode.

When a refrigerant leak occurs and the refrigerant becomes insufficient, the discharge temperature Tcomp becomes higher than the set value Tcomp1, and
4, Tcomp> Tcomp1, and the determination of “NO” proceeds to step 76, where it is determined that “the refrigerant is insufficient” and the step 77 is performed.
Displays an abnormal signal on the refrigerant leak indicator 35 and returns to the normal operation mode. As described above, the refrigerant leak can be automatically detected, and the abnormality of the refrigerator can be found and dealt with at an early stage. The number of rotations of the compressor 11 in the storage unit 29 selected by the selection unit 281 in step 62,
2 has a plurality of set values for the opening degree, the condensation temperature, the evaporation temperature, and the discharge temperature of the condenser 2,
If a set value closer to the refrigerant temperature Tc and the refrigerant temperature Te of the evaporator 4 is selected, the refrigeration cycle can be controlled in a shorter time, and refrigerant leakage can be detected in a shorter time. When a flammable refrigerant is used as the refrigerant,
If a certain amount of refrigerant leakage occurs, the system automatically detects the refrigerant leakage and displays a warning signal to alert the user of the danger of fire or explosion. This can be prevented from occurring.

(Embodiment 3) A refrigeration cycle diagram and a block diagram of a refrigeration apparatus according to a third embodiment of the present invention are the same as those of the second embodiment. FIG. 9 is an electric circuit diagram showing the electric connection of the refrigeration apparatus. In the figure, reference numeral 25 denotes a switch for selecting a refrigerant leak detection mode. In the above configuration, the configuration and operation of the control circuit during operation of the refrigeration system will be described with reference to FIG. FIG. 10 is a flowchart showing a program of the refrigerating apparatus stored in the memory 29 of the LSI 24. When the operation instruction is issued, the operation of the refrigeration apparatus starts, and the operation is performed in the normal operation mode. When the switch 25 for selecting the refrigerant leak detection mode is depressed in step 80, the mode shifts to the refrigerant leak detection mode. The subsequent control is performed in step 6 of the second embodiment.
Since the control is the same as that after the first control, detailed description is omitted. In this way, by performing refrigerant leak detection manually,
It is possible to reliably detect refrigerant leakage and refrigerant shortage at the time of installation, test operation, service of operation abnormality, and the like.

(Embodiment 4) A refrigeration cycle diagram and an electric circuit diagram of a refrigeration apparatus according to a fourth embodiment of the present invention are the same as those of the third embodiment. FIG. 11 is a block diagram of the refrigeration apparatus. The difference from the block diagram of FIG. 3 showing the first embodiment is that the refrigerant leak detecting means of the block diagram of the first embodiment is replaced by a refrigerant leak amount determining means 285.
In the above configuration, the configuration and operation of the control circuit during operation of the refrigeration system will be described with reference to FIG. In FIG. 12, steps up to step 53 are the same as those in FIG. When an instruction for operation is issued, the operation of the refrigeration apparatus starts, the operation enters the refrigerant leak detection mode, Tcomp> Tcomp1 in step 53, and when the determination is "NO", Tcomp1-Tcomp is calculated in step 90. If it is 10 degrees or less, the refrigerant leakage amount is determined to be the leakage amount 1 in step 91, and if it is determined to be 20 degrees or less in step 92, the refrigerant leakage amount is determined to be the leakage amount 2 in step 93.
If it is equal to or more than the degree, the refrigerant leakage amount is determined to be the leakage amount 3 in step 94, and the routine proceeds to step 95, where an abnormal signal and the refrigerant leakage amount are displayed on the refrigerant leakage indicator 35. In this way, in addition to performing refrigerant leakage detection, the amount of refrigerant leakage is estimated and displayed, so that the refrigerant can be replenished without excess or shortage at the time of service of a refrigerating machine operation abnormality, etc., and an optimal refrigeration cycle is maintained. As a result, not only the performance can be prevented from being lowered, but also the reliability of the refrigeration cycle component can be prevented from being lowered.

[0026]

As described above, according to the present invention, it is possible to reliably detect the leakage of the refrigerant or to judge the amount of the leaked refrigerant, and to further indicate that the refrigerant has leaked and the amount of the leaked refrigerant. Further, according to the present invention, a refrigerant leak can be automatically detected, and a compressor capable of changing a rotation speed, which has been difficult to determine a refrigerant leak with conventional control, and a throttle opening degree adjustable. Even in a refrigeration system using a simple expansion valve, it is possible to detect and deal with refrigerant leakage at an early stage. Further, according to the present invention, it is possible to reliably detect refrigerant leakage or refrigerant shortage at the time of installation, test operation, service, and the like. The present invention performs reliable detection of refrigerant leakage, thereby not only operating at an abnormally high discharge temperature, but also preventing an abnormal decrease in performance and preventing a decrease in reliability of refrigeration cycle parts. can do. In addition, the present invention displays the amount of refrigerant to be refilled, so that the refrigerant can be replenished without any excess or shortage at the time of service, the optimal refrigeration cycle can be maintained, and not only the performance is prevented from deteriorating, but also the refrigeration cycle It is possible to prevent a decrease in the reliability of parts. In addition, the present invention displays a caution signal when a refrigerant leaks by a certain amount or more, alerts the user, and can prevent a flammable refrigerant from igniting and causing a fire or explosion. .

[Brief description of the drawings]

FIG. 1 is a refrigeration cycle diagram of a refrigerant leak detection device of a refrigeration system showing one embodiment of the present invention.

FIG. 2 is an electric circuit diagram of a refrigerant leak detection device of a refrigeration system showing one embodiment of the present invention.

FIG. 3 is a block diagram of a refrigerant leak detection device of a refrigeration system showing one embodiment of the present invention.

FIG. 4 is a flowchart of a refrigerant leak detection device of a refrigeration system showing one embodiment of the present invention.

FIG. 5 is a refrigeration cycle diagram of a refrigerant leak detection device of a refrigeration system showing another embodiment of the present invention.

FIG. 6 is an electric circuit diagram of a refrigerant leak detection device of a refrigeration system showing another embodiment of the present invention.

FIG. 7 is a block diagram of a refrigerant leak detection device of a refrigeration system showing another embodiment of the present invention.

FIG. 8 is a flowchart of a refrigerant leak detection device of a refrigeration system showing another embodiment of the present invention.

FIG. 9 is an electric circuit diagram of a refrigerant leak detection device of a refrigeration system showing still another embodiment of the present invention.

FIG. 10 is a flowchart of a refrigerant leak detection device of a refrigeration system showing still another embodiment of the present invention.

FIG. 11 is a block diagram of a refrigerant leak detection device of a refrigeration system showing still another embodiment of the present invention.

FIG. 12 is a flowchart of a refrigerant leak detection device of a refrigeration system showing still another embodiment of the present invention.

FIG. 13 is a refrigeration cycle diagram showing a conventional refrigeration apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Capillary tube 4 Evaporator 5 Condensed refrigerant temperature detector (condensed refrigerant temperature detecting means) 6 Evaporated refrigerant temperature detector (evaporated refrigerant temperature detecting means) 7 Discharged refrigerant temperature detector (discharged refrigerant temperature detecting means) 8) Condenser blower 9 Evaporator blower 11 Compressor with variable rotation speed 12 Expansion valve with adjustable throttle opening 20 Operation switch 24 Microcomputer 25 Switch 29 Memory (storage means) 31 Condenser blower rotation speed control device (Condenser temperature adjusting means) 33 Evaporator blower rotation speed control device (evaporator temperature adjustment means) 35 Display (display means) 37 Compressor rotation speed control device (compressor rotation speed fixing means) 39 Expansion valve drive device ( Expansion valve opening fixing means)

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Yukio Watanabe 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.

Claims (19)

[Claims] 1. A condensed refrigerant temperature detector for detecting a temperature of a refrigerant flowing through the condenser by forming a refrigerating cycle by connecting a compressor, a condenser, a throttle device, and an evaporator in a ring shape, and the evaporator. An evaporating refrigerant temperature detector for detecting the temperature of the refrigerant flowing through the compressor, a discharged refrigerant temperature detector for detecting the discharged refrigerant temperature of the compressor, and adjusting the condensed refrigerant temperature to a constant value by an output signal of the condensed refrigerant temperature detector. Condensing refrigerant temperature adjusting means, evaporating refrigerant temperature adjusting means for adjusting the evaporating refrigerant temperature to a constant value by an output signal of the evaporating refrigerant temperature detector, and comparing the output signal of the discharged refrigerant temperature detector with a set value. Temperature difference calculating means for calculating a temperature difference, wherein the condensed refrigerant temperature and the evaporated refrigerant temperature are adjusted to a constant value by the condensed refrigerant temperature adjusting means and the evaporative refrigerant temperature adjusting means, and are calculated by the temperature difference calculating means. A refrigerant leakage detection device for a refrigeration system, wherein refrigerant leakage of a refrigeration cycle is detected based on the detected temperature difference. 2. The refrigerant of a refrigeration system according to claim 1, wherein said compressor having a variable number of revolutions includes a compressor revolution number fixing means for fixing the number of revolutions of said compressor to a constant value. Leak detection device. 3. The refrigerant leak detection device for a refrigeration system according to claim 1, wherein the expansion device is a capillary tube. 4. The expansion device according to claim 2, wherein an expansion valve capable of adjusting a throttle opening is used as said expansion device, and expansion valve opening fixing means for fixing the opening of said expansion valve to a constant value is provided.
A refrigerant leak detection device for a refrigeration device according to claim 1. 5. A condenser blower rotation speed adjusting means capable of continuously or intermittently changing the rotation speed of a blower as said condensing refrigerant temperature adjusting means, and a rotating speed of a blower as said evaporating refrigerant temperature adjusting means. The refrigerant leak detection device for a refrigeration system according to any one of claims 1 to 4, wherein an evaporator blower rotation speed adjusting means capable of continuously or intermittently changing the rotation speed is used. 6. A condenser pump rotation speed adjusting means capable of continuously or intermittently changing the rotation speed of a pump as said condensing refrigerant temperature adjusting means, and a pump rotation speed as said evaporating refrigerant temperature adjusting means. The refrigerant leak detection device for a refrigeration system according to any one of claims 1 to 4, wherein an evaporator pump rotation speed adjusting means capable of continuously or intermittently changing the rotation speed is used. 7. A plurality of preset values for the condensed refrigerant temperature adjusted by the condensed refrigerant temperature adjusting means and a plurality of preset values for the evaporated refrigerant temperature adjusted by the evaporative refrigerant temperature adjusting means are provided. 7. A refrigerant leak detecting device for a refrigerating device according to claim 1, further comprising a set value selecting means for selecting an optimum set value in accordance with an operation state of the refrigerating device. . 8. A plurality of preset values for presetting the number of revolutions of the compressor and preset values for the degree of opening of the expansion valve, each of which is optimally set in accordance with the operation state of the refrigerating apparatus. 5. The refrigerant leak detecting device for a refrigeration system according to claim 4, further comprising a set value selecting means for selecting a value. 9. The refrigeration system according to claim 1, further comprising automatic refrigerant leakage detection means for accumulating the operation time of the refrigeration system and detecting refrigerant leakage at regular time intervals. Refrigerant leak detection device of the device. 10. The refrigerant leak detection device for a refrigerating device according to claim 1, further comprising an automatic refrigerant leak detection means for detecting a refrigerant leak when the operation of the refrigerating device is started. 11. The refrigeration system according to claim 1, further comprising an automatic refrigerant leakage detection means for detecting refrigerant leakage after a lapse of a predetermined time from the start of operation of the refrigeration system. Refrigerant leak detection device. 12. The refrigerant leak detecting device for a refrigeration system according to claim 1, further comprising a manual refrigerant leak detecting means capable of detecting a refrigerant leak at an arbitrary timing. 13. The refrigeration system according to claim 1, further comprising a refrigerant leakage display unit for displaying that the refrigerant leakage has occurred when the refrigerant leakage is detected. Refrigerant leak detector for refrigeration equipment. 14. When a refrigerant leak is detected, an output signal of the discharged refrigerant temperature detector is compared with a set value, a refrigerant leak amount is determined based on the calculated temperature difference, and a refrigerant to be refilled into the refrigeration system is provided. The refrigerant leak detecting device for a refrigeration system according to any one of claims 1 to 13, further comprising a refrigerant leak display means for displaying an amount. 15. When a flammable refrigerant is used as a refrigerant and refrigerant leakage is detected, an output signal of the discharged refrigerant temperature detector is compared with a set value, and a refrigerant leakage amount is determined from a calculated temperature difference. If a certain amount of refrigerant leaks,
The refrigerant leak detecting device for a refrigeration system according to any one of claims 1 to 14, further comprising a refrigerant leak display means for displaying a caution signal. 16. A refrigeration cycle is constituted by connecting a compressor, a condenser, a throttle device, and an evaporator in a ring shape, and the condensing refrigerant temperature of the condenser and the evaporating refrigerant temperature of the evaporator are set to a predetermined constant value. After adjusting to a value, a refrigerant refrigerant temperature of the compressor is detected, and refrigerant leakage of the refrigeration cycle is detected by a temperature difference calculated by the detected refrigerant refrigerant temperature and a set value. Refrigerant leak detection method. 17. A refrigerating cycle comprising a compressor having a variable number of revolutions, a condenser, an expansion valve capable of adjusting a throttle opening, and an evaporator, which are annularly connected to each other to form a refrigeration cycle. After fixing the number and the degree of opening of the expansion valve to a predetermined constant value, the condensing refrigerant temperature of the condenser and the evaporating refrigerant temperature of the evaporator are adjusted to a predetermined constant value. A refrigerant leak of a refrigeration cycle is detected by a temperature difference calculated based on the detected refrigerant temperature and a set value. 18. A refrigeration cycle is constituted by annularly connecting a compressor, a condenser, a throttle device, and an evaporator, and the condensing refrigerant temperature of the condenser and the evaporating refrigerant temperature of the evaporator are set to a predetermined constant value. After adjusting to the value, the refrigerant discharge temperature of the compressor is detected, and the refrigerant leakage amount is determined based on a temperature difference calculated from the detected discharge refrigerant temperature and a set value,
A method for detecting a refrigerant leak in a refrigeration apparatus, comprising displaying a warning signal on the refrigeration apparatus due to the amount of refrigerant leakage, the amount of refrigerant to be replenished, or a certain amount of refrigerant leakage. 19. A refrigerating cycle comprising a compressor having a variable number of revolutions, a condenser, an expansion valve capable of adjusting a throttle opening, and an evaporator connected in a ring shape to form a refrigeration cycle. After fixing the number and the degree of opening of the expansion valve to a predetermined constant value, the condensing refrigerant temperature of the condenser and the evaporating refrigerant temperature of the evaporator are adjusted to a predetermined constant value. The detected refrigerant refrigerant temperature is detected, the refrigerant leakage amount is determined by the temperature difference calculated from the detected refrigerant discharge temperature and the set value, and the refrigerant leakage amount to the refrigerating device, the refrigerant amount to be replenished, or a certain amount or more. A method for detecting a refrigerant leak in a refrigerating apparatus, comprising displaying a warning signal due to a refrigerant leak.