JPH05164438A - Abnormal state sensing device of absorption freezer - Google Patents

Abstract

PURPOSE:To perform a fast repairing and maintenance work of an absorption freezer and avoid a stopped state of the absorption freezer by a method wherein the absorption freezer is provided with an abnormal state sensor for calculating a cold water load and a mean value of actual temperature differences of a condensor, comparing the mean value of the temperature differences with the cold water load and outputting an abnormal signal. CONSTITUTION:When an absorption freezer is being operated, an abnormal state sensor 42 inputs temperature signals from cold water sensors 36, 37, a condensing temperature sensor 38 and cooling water temperature sensors 40, 41, detects a load in reference to a temperature difference at cold water inlet port and cold water outlet port and an actual temperature difference under a 100% load and at the same time calculates an actual logarithmic mean temperature difference of the condensor 7. In the case that this logarithmic mean temperature difference exceeds an abnormal line of the logarithmic mean temperature difference of the load at that time, the abnormal state sensor 42 outputs an abnormal state signal and informs a user of an abnormal state of the condensor 7. Accordingly, even in the case that the absorption freezer is under a partial load in spring, etc., other than summer season, it may detect the abnormal state and perform a fast repairing and inspection work for abnormal state of the condensor 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption refrigerator, and more particularly to an abnormality detection device for an absorption refrigerator which detects an abnormality of a condenser.

[0002]

2. Description of the Related Art For example, in Japanese Unexamined Patent Publication No. 1-142374, a temperature detector and a pressure detector are installed in an internal space of an evaporator, and output signals from the respective detectors are input, and these signals are predetermined. Disclosed is a refrigerator protection device that includes a setting device that outputs a refrigerator stop signal and an alarm signal when a value is reached.

[0003]

In the above-mentioned prior art, when the refrigerator is, for example, an absorption refrigerator and the abnormality of the condenser due to contamination of the cooling water system other than the evaporator is detected, the evaporator is generally used. In the same manner as above, the rise in the pressure of the condenser or the rise in the temperature of the condensed refrigerant in the condenser is detected, and
Compare with the design value when NPUT is 100%. For this reason,
When the absorption type refrigerating machine is in partial load such as spring or autumn other than summer or when there is almost no load, the abnormality of the condenser cannot be accurately detected, so that there is a problem that the detection of the abnormality of the refrigerating machine is delayed.

[0004]

In order to solve the above-mentioned problems, the present invention provides an absorption refrigerating machine in which a high temperature regenerator 4, a condenser 7, an evaporator 1 and an absorber 2 are connected by piping. Cold water temperature detectors 36 and 37 for detecting the cold water inlet temperature and outlet temperature of the evaporator 1, cooling water temperature detectors 40 and 41 for respectively detecting the cooling water inlet and outlet temperatures of the condenser 7, and the condenser 7 Temperature detector 38 for detecting the temperature of the outlet side refrigerant liquid, and each cold water temperature detector 36, 37
The cold water load is calculated from the difference between the detected temperatures of the cold water and the temperature difference between the cold water at the time of 100% load, and each cooling water temperature detector 4
0 and 41 and the temperature detected by the refrigerant temperature detector 38, the actual logarithmic average temperature difference of the condenser 7 is calculated, and the logarithmic average temperature difference is compared with the cold water load to output an abnormal signal. And an abnormality detection device for surely detecting an abnormality of the condenser even when the absorption refrigerator is partially loaded.

Further, a pressure detector 52 for detecting the pressure in the condenser 7, cooling water temperature detectors 40, 41 for detecting the cooling water inlet temperature and the outlet temperature of the condenser 7, respectively, and cold water for the evaporator 1 The saturation temperature of the condenser 7 is obtained from the pressures detected by the cold water temperature detectors 36 and 37 that detect the inlet temperature and the outlet temperature, respectively, and the saturation temperature and the cooling water temperature detector 40 of the condenser 7. , 41 calculates the actual logarithmic mean temperature difference of the condenser 7 from the cooling water inlet temperature and the outlet temperature, and the difference between the detected temperatures of the respective cold water temperature detectors 36, 37 and the cold water inlet / outlet temperature at 100% load. A cold water load is calculated from the difference, and an abnormality detector that outputs an abnormal signal by comparing the ideal logarithmic mean temperature difference and the actual logarithmic mean temperature difference with respect to this cold water load is provided, and at the time of partial load of the absorption refrigerator. Is also abnormal Condenser 7 before the cold water temperature changes Te
The present invention provides an abnormality detection device that reliably detects the abnormality.

Cooling water temperature detectors 40 and 41 for respectively detecting the cooling water inlet temperature and the outlet temperature of the condenser 7, and a condensing temperature detector 38 for detecting the refrigerant condensing temperature of the condenser 7.
The cold water temperature detectors 36 and 37 for detecting the cold water inlet temperature and the outlet temperature of the evaporator 1, respectively, and the relationship between the cold water load and the ideal logarithmic mean temperature difference when the condenser 7 is healthy are stored. The difference between the temperatures detected by the temperature detectors 36 and 37 and 10
The cold water load is calculated from the cold water inlet / outlet temperature difference at 0% load, the ideal logarithmic average temperature difference corresponding to this cold water load is obtained from the relationship between the cold water load and the ideal logarithmic average temperature difference, and each cold water temperature is detected. 36, 37, condensation temperature detector 38
And the actual logarithmic mean temperature difference of the condenser 7 is calculated from the temperatures detected by the cooling water temperature detectors 40 and 41, and the actual logarithmic mean temperature difference and the ideal logarithmic mean temperature difference are compared with respect to the ideal logarithmic mean temperature difference. It is equipped with an anomaly detector that outputs an anomaly signal when the ratio of the actual logarithmic average temperature difference is equal to or greater than a predetermined value, and it accurately distinguishes changes such as chilled water temperature due to changes in chilled water load from abnormal changes. The present invention provides an abnormality detecting device for surely detecting an abnormality of the condenser 7 even under partial load.

[0007]

During operation of the absorption chiller, the abnormality detector 42 inputs temperature signals from the cold water temperature detectors 36, 37, the condensation temperature detector 38 and the cooling water temperature detectors 40, 41 to obtain 100%.
The load is calculated from the cold water inlet / outlet temperature difference at the time of load and the actual cold water inlet / outlet temperature difference, and the actual logarithmic average temperature difference of the condenser 7 is calculated. If the logarithmic average temperature difference exceeds the logarithmic average temperature difference abnormal line of the load at that time, the abnormality detector 42 outputs an abnormal signal and the condenser 7
The abnormality can be detected, so that the abnormality can be detected even when the absorption refrigerator has a partial load in the spring other than the summer, and it is possible to perform maintenance and inspection work early for the abnormality of the condenser 7. ..

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows that the refrigerant is, for example, water or an absorbing liquid (solution).
FIG. 1 is a schematic configuration diagram of an absorption chiller-heater, which is an absorption refrigerator using a lithium bromide (LiBr) solution as a solvent.
Reference numeral 2 is an absorber, 3 is an evaporator absorber body (hereinafter, referred to as a lower body) accommodating the evaporator 1 and the absorber 2, 4 is a high temperature regenerator which is equipped with a gas burner 5 and is heated by a high temperature heat source, 6
Is a low temperature regenerator, 7 is a condenser, 8 is a low temperature regenerator condenser cylinder (hereinafter referred to as the upper cylinder) that houses the low temperature regenerator 6 and the condenser 7, 9 is a low temperature heat exchanger, and 10 is a high temperature heat exchanger. 11 to 15 are absorption liquid pipes, 16 is an absorption liquid pump, 17 and 18 are refrigerant pipes, 19 is a refrigerant circulation pipe, 20 is a refrigerant pump, 21 is a gas pipe connected to the gas burner 5, and 22 is a heating amount. The control valve and 23 are cold water pipes provided with an evaporator heat exchanger 24 in the middle thereof, and each pipe is connected as shown in FIG.

Further, 25 is a cooling water pipe, and an absorber heat exchanger 26 and a condenser heat exchanger 27 are provided in the middle of the cooling water pipe 25. Reference numeral 28 is a refrigerant bypass pipe that connects the refrigerant reservoir 29 of the evaporator 1 and the absorbent liquid reservoir 30 of the absorber 2 by pipe, 31 is an on-off valve, and 32 is an absorbent bypass pipe that connects the absorbent pipe 12 and the absorber 2. , 33 is an on-off valve,
34 is a refrigerant vapor bypass pipe connecting the refrigerant pipe 17 and the absorber 2, 35 is an opening / closing valve, and each opening / closing valve 31, 33,
Reference numeral 35 closes when cold water is supplied and opens when hot water is supplied.

Reference numerals 36 and 37 denote first and second temperature detectors, respectively, which are cold water inlet / outlet temperature detectors provided on the inlet side and the outlet side of the evaporator 1 of the cold water pipe 23, and 38 indicates the refrigerant on the outlet side of the condenser 7. A condenser temperature detector provided in the pipe 18, 40 is a cooling water inlet temperature detector for detecting the inlet side cooling water temperature of the condenser 7, and 41 is a cooling water outlet temperature for detecting the outlet side cooling water temperature of the condenser 7. A temperature detector, 42 is an abnormality detector for detecting the abnormality detection device of the condenser 2 by inputting a temperature signal from each of the temperature detectors. The abnormality detector 42 is, for example, a control panel of an absorption refrigerator (see FIG. (Not shown), and is composed of a microcomputer. Reference numeral 43 is a notification device which is provided on the control panel similarly to the abnormality detector 42 and which operates by receiving a signal from the abnormality detector. This notification device 43
Is composed of a display device 44 having a plurality of segment elements and a buzzer 45, for example. And the display device 4
4 is, for example, ALA based on the signal from the abnormality detector 42.
Blink the letters RM.

The configuration of the abnormality detector 42 will be described below with reference to FIG.
It will be explained based on. 46 is the first and second temperature detectors 3
6, 37, the condensed refrigerant temperature detector 38, the cooling water inlet temperature detector 40, and the cooling water outlet temperature detector 41, inputs the signals, converts the signals, and outputs the signals to the central processing unit (hereinafter referred to as CPU) 47. Reference numeral 48 denotes an interface, 48 is a storage device (hereinafter referred to as ROM) in which an arithmetic program related to the present invention is stored, and 49 is an output interface for inputting a signal from the CPU 46 and outputting it to the notification device 41.
50, a signal generator (hereinafter referred to as CLOCK) that outputs a signal at predetermined time intervals, 51 is a readable and erasable storage device (hereinafter referred to as R, which stores the temperature detected by each temperature detector).
AM).

In the ROM 48, the cooling water inlet temperature T
1. Calculate the actual logarithmic average temperature difference Tlm, which is the average value of the actual temperature difference of the condenser 7, from the cooling water outlet temperature T2 and the condensed refrigerant temperature T3.

[0013]

[Equation 1] And a program for calculating the cold water load from the difference between the cold water inlet temperature and the cold water outlet temperature at the time of 100% load in the normal operation of the absorption chiller, and the difference between the actually detected cold water inlet temperature and the cold water outlet temperature, The relationship between the cold water load and the logarithmic average temperature difference of the condenser 7 shown in FIG. 3 is stored. In FIG. 3, a is an ideal line showing the relationship between the cold water load and the logarithmic average temperature difference when the absorption refrigerator is operating normally, and b is an abnormal line that outputs an abnormal signal.

During the cold water supply operation of the absorption refrigerating machine, the refrigerant evaporated in the high temperature regenerator 4 flows to the condenser 7 via the low temperature regenerator 6 as in the conventional absorption refrigerating machine, and the condenser heat exchanger. After exchanging heat with the cooling water flowing through 27 to condense and liquefy, it flows to the evaporator 1 through the refrigerant pipe 18. The refrigerant exchanges heat with the water flowing through the evaporator heat exchanger 24 to evaporate, and the water flowing through the evaporator heat exchanger 24 is cooled by the heat of vaporization.
Then, cold water circulates through the load. The refrigerant evaporated in the evaporator 1 is absorbed by the absorbing liquid in the absorber 2. The absorption liquid that has absorbed the refrigerant and becomes thin in concentration is sent to the high temperature regenerator 4 via the low temperature heat exchanger 9 and the high temperature heat exchanger 10 by the operation of the absorption liquid pump 16. The absorption liquid sent to the high temperature regenerator 4 is heated by the burner 5 to evaporate the refrigerant, and the medium concentration absorption liquid flows through the high temperature heat exchanger 10 to the low temperature regenerator 6. In the low temperature regenerator 6, the absorbing liquid is heated by the refrigerant vapor flowing from the high temperature regenerator 10 through the refrigerant pipe 17, and the refrigerant vapor is further separated to have a high concentration. The absorption liquid having a high concentration is sent to the absorber 2 after being lowered in temperature through the low temperature heat exchanger 9 and is sprayed.

Abnormality detection when the absorption refrigerator is operated as described above will be described with reference to the flow chart of FIG. The respective temperatures detected by the first and second temperature detectors 36 and 37, the condensed refrigerant temperature detector 38, the cooling water inlet temperature detector 40, and the cooling water outlet temperature detector 41 are determined by the input interface 46 and the CPU 47. It is temporarily stored in the RAM 51 via the. Then, the cold water inlet temperature, the cold water outlet temperature, the condensed refrigerant temperature, the cooling water inlet temperature, and the cooling water outlet temperature stored in the RAM 51 are read into the CPU 47 based on the signal from the CLOCK 50 and read from the ROM 48. The equation number 1, the program, and the relationship between the cold water load and the logarithmic mean temperature difference are read. Then, the load (%) is calculated from the actual cold water inlet / outlet temperature difference and the cold water inlet / outlet temperature difference (5 ° C.) at 100% load. Here, for example, when the cold water inlet temperature is 10 ° C., the cold water outlet temperature is 7 ° C., and the temperature difference is 3 ° C., the load is 3/5 =
It becomes 0.6 (60%).

Further, the CPU 47 calculates the actual logarithmic mean temperature difference Tlm of the condenser 7 from the condensed refrigerant temperature, the cooling water inlet temperature and the cooling water outlet temperature, and the equation 1 above. Here, for example, the heat exchange performance in the condenser 7 is deteriorated due to contamination of the condenser heat exchanger 27, and the cooling water inlet temperature is, for example, 34 ° C., the cooling water outlet temperature is, for example, 36 ° C., and the condensed refrigerant temperature is, for example, At 42 ° C, the actual logarithmic average temperature difference is about 7.7 ° C. Then, this logarithmic average temperature difference is a value (6.5%) when the load of the abnormal line is 60% shown in FIG.
C.), the CPU 47 outputs an abnormality signal via the output interface 49, and the abnormality detector 42 outputs the abnormality signal to the notification device 43. Then, while ALARM is displayed on the display device 44 of the notification device 43,
The buzzer-45 sounds to notify the abnormality of the absorber 2.

When the cold water load is 60%, for example, the condensed logarithmic refrigerant temperature, the cooling water inlet temperature, the cooling water outlet temperature, and the actual logarithmic mean temperature difference Tlm calculated from the above equation 1 are 5.5 ° C. If the load is lower than the value on the abnormal line (6.5 ° C.) when the load is 60%, the CPU 47 does not output the abnormal signal and the notification device 43 does not notify the abnormality. According to the above-described embodiment, the abnormality detector 42 calculates the actual logarithmic mean temperature difference based on the condensed refrigerant temperature, the cooling water inlet temperature, the cooling water outlet temperature, and Equation 1 of the above formula, and the abnormality of the condenser 7 is detected. When the logarithmic average temperature difference occurs and exceeds the abnormal line that is stored in advance, the abnormality detector 42 outputs a signal, so that there is an abnormality in the condenser 7 even in an intermediate period other than summer or winter. If it occurs, it is possible to detect an abnormality during partial load of the absorption chiller-heater and deal with it at the initial stage of occurrence of the abnormality. As a result, maintenance and inspection of the absorption chiller-heater can be performed more reliably. ..

In the above embodiment, the logarithmic mean temperature difference was calculated based on the equation 1 to detect an abnormality. However, when the temperature rise of the cooling water in the condenser 7 is substantially uniform,
Instead of the number 1 in the above formula

[0019]

[Equation 2] Even when the average value T of the actual temperature differences is calculated using, the same operational effect can be obtained. The second embodiment of the present invention will be described below. It should be noted that the configuration, which is not particularly described, is the same as that of the above-described embodiment, and detailed description thereof will be omitted. Reference numeral 52 is a pressure detector that detects the pressure in the condenser 7 (condensing pressure). In this embodiment, the ROM 46 of the abnormality detector 42 stores the condensation pressure of the condenser 7 in the ROM 46.
A program (calculation formula or steam diagram showing the relationship between steam temperature and pressure) for determining the saturation temperature of is stored. Then, the saturation temperature of the condenser 7 obtained from the pressure inside the condenser 7 is substituted for the condensation refrigerant temperature T3 in the equation 1 to calculate the actual logarithmic mean temperature difference of the condenser 7, and When the value exceeds the abnormal line, the abnormality detection device 42 outputs an abnormal signal.

By calculating the actual logarithmic mean temperature difference of the condenser 7 using the saturation temperature of the condenser 7 as in the above embodiment, the condensed refrigerant temperature is detected by the condensed refrigerant temperature detector 38 and the logarithmic mean temperature is detected. The logarithmic average temperature difference can be calculated more accurately as compared with the case of obtaining the difference, and as a result, the abnormality of the condenser 7 can be detected more accurately before the change in the cold water temperature due to the abnormality occurs. it can.

Further, as shown in the above embodiment, the condenser 7
The actual logarithmic average temperature difference is calculated, and the ratio of the cold water load to this logarithmic average temperature difference is calculated. For example, the cold water load is 60%, the actual logarithmic average temperature difference is 7.7 ° C, and the ratio of the load to the logarithmic average temperature difference is approximately 0.13 ° C /%.
Even when the abnormality detecting device 42 outputs an abnormality signal when this ratio exceeds a predetermined value, for example, 0.12 ° C./%, the same effect as that of the above-described embodiment can be obtained.

Further, the actual logarithmic mean temperature difference of the condenser 7 is calculated based on the cooling water inlet temperature, the cooling water outlet temperature, the condensed refrigerant temperature or the saturation temperature of the condenser 2, and the ideal logarithmic mean temperature difference of these values is calculated. Calculate the ratio to. Then, when this ratio exceeds a predetermined value, the abnormality detector 42 outputs an abnormality signal. For example, when the load is 60%, the actual logarithmic average temperature difference is 7 ° C., and the ideal logarithmic average temperature difference is 5 ° C., the ratio is 7/5 = 1.4, which is a predetermined value (for example, 1.3).
In the above case, the abnormality detector 42 outputs an abnormality signal.
Further, in the case where the actual heat transmission coefficient which is the reciprocal of the above ratio is calculated and the abnormality detector 42 outputs the abnormality signal when this heat transmission coefficient becomes a predetermined value (for example, 80%) or less. Can also obtain the same effect.

In the above embodiment, the description has been given based on the absorption chiller-heater capable of supplying cold water or hot water. However, also in the absorption chiller supplying only chilled water, an abnormality detector is provided as in the above embodiment. As a result, the same operational effect can be obtained.

[0024]

The present invention is an abnormality detecting device for an absorption refrigerating machine constructed as in the above embodiment, wherein the cold water inlet and outlet temperatures of the evaporator are respectively detected by the cold water temperature detectors to cool the condenser. The water inlet and outlet temperatures are detected by the cooling water temperature detectors, the refrigerant condensation temperature of the condenser is detected by the condensation temperature detectors, and the abnormality detector detects the difference between the temperature detected by each cold water temperature detector and 100% load. The cold water load is calculated from the cold water inlet / outlet temperature difference of, and the average value of the actual temperature difference of the condenser is calculated from the detected temperature of each cooling water temperature detector and the condensation temperature detector. Since the abnormal value is output by comparing the average value with the cold water load, it is possible to reliably detect the abnormality of the condenser even during partial load in the intermediate period other than summer, for example, and as a result, the absorption refrigerator Perform maintenance and inspections at an early stage to It is possible to avoid the stop.

Further, the saturation temperature of the condenser is obtained from the pressure in the condenser, the average value of the actual temperature difference of the absorber is calculated from the saturation temperature, the cooling water inlet temperature and the outlet temperature, and the actual temperature difference is calculated. By outputting the abnormality signal by comparing the average value of the above with the cold water load, it is possible to detect the abnormality of the absorber more accurately before the abnormality occurs and the change in the cold water temperature occurs.

Further, the abnormality detector stores the relationship between the cold water load when the condenser is healthy and the average value of the ideal temperature difference. The cold water load is calculated and the ideal temperature corresponding to this cold water load is stored. The average value of the difference is obtained from the relationship between the cold water load and the average value of the ideal temperature difference, and the actual temperature difference of the condenser from the refrigerant condensation temperature of the condenser, the condenser inlet temperature and the outlet temperature of the cooling water. When the average value is calculated, the average value of the actual temperature difference and the average value of the ideal temperature difference are compared, and the ratio of the average value of the actual temperature difference to the average value of the ideal temperature difference is equal to or more than a predetermined value. By outputting an error signal, it is possible to reliably distinguish between changes in chilled water temperature due to load fluctuations and the occurrence of abnormalities, and to detect abnormalities.As a result, maintenance and inspection work for absorption chillers can be performed more accurately. be able to.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an absorption refrigerator according to an embodiment of the present invention.

FIG. 2 is a block diagram of an anomaly detector.

FIG. 3 is a relationship diagram between a load and a logarithmic average temperature difference.

FIG. 4 is a flowchart for explaining the operation of the abnormality detection device.

[Explanation of symbols]

 1 Evaporator 2 Absorber 4 High temperature regenerator 6 Low temperature regenerator 9 Low temperature heat exchanger 10 High temperature heat exchanger 36 Cold water temperature detector 37 Cold water temperature detector 38 Condensation temperature detector 40 Cooling water inlet temperature detector 41 Cooling water outlet Temperature detector 42 Abnormality detector

Claims (3)

[Claims] 1. An absorption refrigerating machine in which a regenerator, a condenser, an evaporator, an absorber and the like are connected by piping, and a cold water temperature detector for detecting a cold water inlet temperature and an outlet temperature of the evaporator, and a condenser. Cooling water temperature detector that detects the cooling water inlet temperature and outlet temperature of the condenser, a condensation temperature detector that detects the refrigerant condensation temperature of the condenser, and the difference between the detected temperature of each cold water temperature detector and 100% load The cold water load is calculated from the cold water inlet / outlet temperature difference, and the average value of the actual temperature difference of the condenser is calculated from the detected temperature of each cooling water temperature detector and the condensation temperature detector, and the average of this actual temperature difference is calculated. An abnormality detection device for an absorption chiller, comprising: an abnormality detector that compares a value with a cold water load and outputs an abnormality signal. 2. An absorption refrigerating machine in which a regenerator, a condenser, an evaporator, an absorber, etc. are connected by piping, a pressure detector for detecting the pressure in the condenser, a cooling water inlet temperature of the condenser, and A cooling water temperature detector that detects each outlet temperature,
Cooling water temperature detector that detects the cold water inlet temperature and outlet temperature of the evaporator, and the saturation temperature of the condenser is calculated from the pressure detected by the pressure detector, and the cooling water inlet that is detected by this saturation temperature and cooling water temperature detector The average value of the actual temperature difference of the condenser is calculated from the temperature and the outlet temperature, and the cold water load is calculated from the difference in the detected temperature of each cold water temperature detector and the difference between the cold water inlet and outlet temperatures at 100% load, An abnormality detection device for an absorption chiller, comprising: an abnormality detector that outputs an abnormality signal by comparing the average value of the ideal temperature difference with the average value of the actual temperature difference with respect to the cold water load. 3. An absorption refrigerating machine in which a regenerator, a condenser, an evaporator, an absorber and the like are connected by piping, and a cooling water temperature detector for detecting a cooling water inlet temperature and a cooling water inlet temperature of the condenser, respectively. Condensation temperature detector that detects the refrigerant condensation temperature of the condenser, cold water temperature detector that detects the cold water inlet temperature and outlet temperature of the evaporator, and the average of the cold water load and the ideal temperature difference when the condenser is healthy. The relationship with the value is stored, the cold water load is calculated from the difference in the detected temperature of each cold water temperature detector and the difference in the cold water inlet and outlet temperatures at 100% load, and the average of the ideal temperature differences corresponding to this cold water load is calculated. Obtain the value from the relationship between the cold water load and the average value of the ideal temperature difference, and calculate the average value of the actual temperature difference of the condenser from the detection temperature of each cooling water temperature detector and condensation temperature detector, The average value of this actual temperature difference and the ideal temperature difference Absorption equation characterized by including an abnormality detector that outputs an abnormality signal when the ratio of the average value of the actual temperature difference to the average value of the ideal temperature difference is greater than or equal to a predetermined value Refrigerator abnormality detection device.