JP7698538B2 - Information processing device, program, abnormality detection method, abnormality detection system, and cooling storage facility - Google Patents

Description

This technology relates to an information processing device, a program, an anomaly detection method, an anomaly detection system, and a cooling storage facility.

Refrigerated storage units are operated continuously to maintain the storage chamber at a specified cooling setting temperature. For this reason, measures have been taken to prevent unintended operation stoppages and deterioration of operating performance due to malfunctions, etc., for refrigerated storage units. For example, Patent Document 1 discloses a technology that uses a gas detector to detect refrigerant gas leaks (refrigerant leaks), which are one of the defects that reduce the performance of refrigerated storage units. The technology of Patent Document 1 takes into account the operating state of the compressor, etc., in addition to the results of refrigerant leak detection by a gas detector with high sensitivity, to ensure that refrigerant leaks are detected reliably in a short time.

Patent No. 5541945

However, gas detectors are relatively expensive, and there are cost issues, especially when installing highly sensitive gas detectors in individual cold storage units.

This technology was developed in consideration of the above circumstances, and one of its objectives is to provide an abnormality detection system that can detect malfunctions (abnormalities) caused by refrigerant leaks in a refrigerant storage tank without installing a gas detector. In another aspect, another objective is to provide an information processing device, a program, an abnormality detection method, and a refrigerant storage tank that can detect malfunctions caused by refrigerant leaks.

The information processing device of the present technology detects an abnormality in a cooling storage facility that includes a storage facility body having a storage chamber, a cooling unit including a compressor, a condenser, a pressure reducing mechanism, an evaporator, a refrigerant pipe for circulating a refrigerant through these, and a heater for heating the evaporator, a first temperature sensor capable of detecting the temperature of the evaporator at the inlet of the evaporator, and a second temperature sensor capable of detecting the temperature of the air in the storage chamber, and is configured to perform a cooling operation in which air from the storage chamber is taken into the cooling unit, cooled, and then returned to the storage chamber. This information processing device includes an acquisition unit that acquires information about the operating state of the compressor and information detected by the first temperature sensor and the second temperature sensor, a determination unit that determines that a refrigerant leak has occurred when a first temperature difference, which is the temperature difference between the temperature of the air in the storage chamber and the temperature at the inlet of the evaporator when the operating state of the compressor is increasing, falls outside an appropriate range of the temperature difference between the air temperature in the storage chamber and the inlet of the evaporator, which is determined in advance based on information acquired by the acquisition unit when there is no refrigerant leakage from the refrigerant pipe, and an output unit that outputs information indicating an abnormality when the determination unit determines that there is a refrigerant leak.

When there is an abnormality in the cooling storage, the cooling capacity of the cooling storage decreases, and the compressor's driving state to achieve a specified cooling performance increases. For example, when constant speed control is adopted as the compressor operation control method, the operation rate increases, and when inverter control is adopted, the average rotation rate increases. In addition, as an example of an abnormality in the cooling storage, when gaseous refrigerant gradually leaks from the refrigerant pipe (slow leak of refrigerant gas), the refrigerant gas supplied to the evaporator is insufficient. As a result, the evaporator's temperature drops only on the inlet side, and the temperature on the outlet side increases, and the cooling performance is considered to decrease. In such a case, although the temperature at the inlet of the evaporator decreases, the temperature of the air in the storage room (hereinafter, sometimes simply referred to as the "inside temperature") is difficult to decrease to a temperature corresponding to the decrease in the evaporator inlet temperature, and the first temperature difference, which is the temperature difference between the evaporator inlet temperature detected by the first temperature sensor and the inside temperature detected by the second temperature sensor, may be larger than the temperature difference when refrigerant gas is not leaking.

According to the above configuration, the temperature difference (first temperature difference) between the evaporator inlet temperature and the inside temperature is monitored, an appropriate range is set, and it is determined whether the first temperature difference is appropriate, thereby estimating whether the cause of an abnormality in the cooling storage is due to a refrigerant leak. In other words, if a judgment condition is met that includes a condition that the first temperature difference is outside the appropriate range, it is determined that there is a refrigerant leak. This makes it possible to detect a malfunction of the cooling storage caused by a refrigerant leak. Furthermore, when a malfunction occurs in the cooling storage, it is possible to estimate whether the cause is due to a refrigerant leak.

In a preferred embodiment, the condenser includes an inlet through which the refrigerant compressed by the compressor is sent, an outlet through which the refrigerant is sent toward the pressure reducing mechanism, and a central portion between the inlet and the outlet, and the cooling storage further includes a third temperature sensor capable of detecting the temperature of the condenser at the central portion of the condenser, and a fourth temperature sensor capable of detecting the temperature of the environment in which the cooling storage is installed. The acquisition unit in the information processing device acquires information detected by the third temperature sensor and the fourth temperature sensor, and the determination unit further determines that a refrigerant leak has occurred when a second temperature difference, which is a temperature difference between the temperature of the environment and the temperature of the central portion of the condenser when the driving state of the compressor is increasing, falls outside an appropriate range of the temperature difference between the temperature of the environment and the temperature of the central portion of the condenser, which is predetermined based on the information acquired by the acquisition unit when there is no refrigerant leakage from the refrigerant pipe.

When a refrigerant leak occurs, the compressor operation rate is increased to lower the temperature of the storage chamber more than when there is no refrigerant leak. Here, as the refrigerant gas decreases, the temperature of the center of the condenser is unlikely to increase to a temperature equivalent to the increase in the compressor operation rate, and the temperature difference between the ambient temperature and the temperature of the center of the condenser may be smaller than when there is no refrigerant gas leakage. With the above configuration, it is possible to determine whether a refrigerant leak has occurred by taking into account the second temperature difference, which is the temperature difference between the ambient temperature and the temperature of the center of the condenser. This makes it possible to more accurately detect malfunctions in the cooling storage caused by refrigerant leaks.

In a preferred embodiment, the cooling unit further includes a heater for heating the evaporator, and the cooling storage is configured to execute a defrosting operation in which the heater heats the evaporator to melt frost adhering to the evaporator when a predetermined defrosting condition is satisfied, and a timer for detecting the time required for the defrosting operation. The acquisition unit acquires information regarding the time required for the defrosting operation detected by the timer, and the determination unit further determines that a refrigerant leak has occurred when the time required for the most recently executed defrosting operation falls outside an appropriate range of the time required for the defrosting operation that is predetermined based on the information acquired by the acquisition unit when there is no refrigerant leakage from the refrigerant pipe.

The first temperature difference may also be large when excessive frost is formed on the evaporator of the cooling storage facility, etc. The amount of frost formed on the cooling storage facility roughly corresponds to the length of the defrosting operation for melting the frost, and whether or not excessive frost is formed on the evaporator can be determined by the time required for the defrosting operation.
According to the above configuration, whether or not there is an excessive amount of frost on the evaporator is determined based on the duration of the most recent defrosting operation, and if there is an excessive amount of frost on the evaporator, even if the first temperature difference is outside the appropriate range, the determination as to whether or not there is a refrigerant leak is not performed. This makes it possible to more accurately detect malfunctions of the cooling unit caused by refrigerant leaks.

In a preferred aspect of the information processing device according to the present technology, the information processing device includes an appropriate range determination unit that determines the appropriate range based on information regarding the first temperature difference when there is no refrigerant leakage from the refrigerant pipe, which information is acquired by the acquisition unit. With the above configuration, it is possible to accurately detect malfunctions of the cooling unit caused by refrigerant leakage.

In a preferred aspect of the information processing device according to the present technology, the cooling unit further includes a heater for heating the evaporator, the storage body includes a heat-insulating housing having an opening on one side, a door for opening and closing the opening, and an opening/closing sensor for detecting the opening and closing of the door, and the cooling storage includes a configuration for performing a defrosting operation for heating the evaporator by the heater to melt frost adhering to the evaporator when a predetermined defrosting condition is satisfied, and a timer for detecting a time required for the defrosting operation. Then, the acquisition unit acquires information detected by the opening/closing sensor and the timer, and the appropriate range determination unit determines the following for the cooling storage:
(a) the information detected within a predetermined time after the defrosting operation is not used as the information regarding the driving state of the compressor;
In the cooling operation, when the period during which the inside temperature is controlled from one cooling upper limit temperature or cooling lower limit temperature to the next cooling upper limit temperature or cooling lower limit temperature is defined as one cycle,
(b) when the fluctuation in the driving state of the compressor during a plurality of consecutive cycles falls within a predetermined range, determining the appropriate range based on information regarding the driving state of the compressor during the plurality of consecutive cycles;
(c) when the fluctuation of the environmental temperature falls within a predetermined range during a plurality of consecutive cycles, determining the appropriate range based on information regarding the driving state of the compressor during the plurality of consecutive cycles; and
(d) when the door is opened or closed during a plurality of consecutive cycles, the information detected during the plurality of consecutive cycles is not used as information regarding the operating state of the compressor;
The information is configured not to be used to determine the appropriate range when any one or more of the above conditions are satisfied. In general, the values detected by the above sensors in a cooling storage unit can be significantly affected by a specific usage state of the cooling storage unit. With the above configuration, it is possible to determine whether a refrigerant leak is occurring by taking into account the characteristics of the cooling storage unit.

In a preferred embodiment of the information processing device according to the present technology, the compressor is subjected to constant speed control in which the rotation speed of the drive motor is kept constant and the compressor is switched between driving and stopping, and the information regarding the drive state of the compressor is the operation rate of the compressor. With the above configuration, an example of the information regarding the drive state of the compressor is clearly presented.

In a preferred embodiment of the information processing device according to the present technology, the compressor is inverter controlled to change the rotation speed of the drive motor, and the information regarding the drive state of the compressor is the rotation speed of the compressor. With the above configuration, another example of the information regarding the drive state of the compressor is clearly presented.

In another aspect, the present technology provides an abnormality detection method for detecting an abnormality in a cooling storage facility that includes a storage facility body having a storage chamber, a cooling unit including a compressor, a condenser, a pressure reducing mechanism, an evaporator, a refrigerant pipe for circulating a refrigerant therethrough, and a heater for heating the evaporator, and further includes a first temperature sensor at an inlet of the evaporator that can detect the temperature of the evaporator, and a second temperature sensor that can detect the temperature of the air in the storage chamber, and is configured to perform a cooling operation in which the air in the storage chamber is taken into the cooling unit, cooled, and then returned to the storage chamber, the method comprising: detecting an abnormality in a cooling storage facility that includes information about the operating state of the compressor and the first temperature sensor; The method includes an acquisition step of acquiring information detected by the first temperature sensor and the second temperature sensor, a determination step of determining that a refrigerant leak has occurred when a first temperature difference, which is the temperature difference between the temperature of the air in the storage chamber and the temperature at the inlet of the evaporator when the driving state of the compressor is increasing, falls outside an appropriate range of the temperature difference between the air temperature in the storage chamber and the inlet of the evaporator, which is determined in advance based on information acquired by the acquisition unit when there is no refrigerant leakage from the refrigerant pipe, and an output step of outputting information indicating an abnormality when the determination unit determines that there is a refrigerant leak.

In another aspect, the present technology is a program for causing a computer to execute detection of an abnormality in a cooling storage facility that includes a storage facility body having a storage chamber, a cooling unit including a compressor, a condenser, a pressure reducing mechanism, an evaporator, a refrigerant pipe for circulating a refrigerant therethrough, and a heater for heating the evaporator, and further includes a first temperature sensor at an inlet of the evaporator that can detect the temperature of the evaporator, and a second temperature sensor that can detect the temperature of the air in the storage chamber, and is configured to execute a cooling operation in which the air in the storage chamber is taken into the cooling unit, cooled, and then returned to the storage chamber, the program including detection of an abnormality in the cooling storage facility that relates to the operating state of the compressor. The present invention provides a program that causes a computer to execute an acquisition step of acquiring information and information detected by the first temperature sensor and the second temperature sensor, a determination step of determining that a refrigerant leak has occurred when a first temperature difference, which is the temperature difference between the temperature of the air in the storage chamber and the temperature at the inlet of the evaporator when the driving state of the compressor is increasing, falls outside an appropriate range of the temperature difference between the temperature of the air in the storage chamber and the temperature at the inlet of the evaporator, which is predetermined based on information acquired by the acquisition unit when there is no refrigerant leakage from the refrigerant pipe, and an output step of outputting information indicating an abnormality when the determination unit determines that there is a refrigerant leak.

In another aspect, the present technology provides a cooling storage comprising: a storage body having a storage chamber; a cooling unit including a compressor, a condenser, a pressure reducing mechanism, an evaporator, a refrigerant pipe for circulating the refrigerant therethrough, and a heater for heating the evaporator; a first temperature sensor capable of detecting the temperature of the evaporator at the inlet of the evaporator; and a second temperature sensor capable of detecting the temperature of the air in the storage chamber, and further comprising: a means for executing a cooling operation in which the air in the storage chamber is taken into the cooling unit, cooled, and then returned to the storage chamber; a means for transmitting information regarding the operating state of the compressor and information acquired by the first temperature sensor and the second temperature sensor to any of the above-described information processing devices connected in a communicable manner; a means for receiving information indicating an abnormality from the information processing device when the information processing device determines that there is a refrigerant leak; and a means for notifying the abnormality based on the received information. This cooling storage may further comprise the information processing device.

In another aspect, the present technology provides an anomaly detection system including a cooling storage, a sensor, and an information processing device. The cooling storage includes a storage body having a storage chamber, a cooling unit including a compressor, a condenser, a pressure reducing mechanism, an evaporator, a refrigerant pipe for circulating the refrigerant therethrough, and a heater for heating the evaporator, a first temperature sensor capable of detecting the temperature of the evaporator at the inlet of the evaporator, and a second temperature sensor capable of detecting the temperature of the air in the storage chamber, and further includes a means for performing a cooling operation in which the air in the storage chamber is taken into the cooling unit, cooled, and then returned to the storage chamber, a means for transmitting information regarding the operating state of the compressor and information acquired by the first temperature sensor and the second temperature sensor to the information processing device connected to the information processing device in a communicable manner, a means for receiving information indicating the anomaly from the information processing device when the information processing device determines that there is a refrigerant leak, and a means for notifying the anomaly based on the received information. The information processing device includes an acquisition unit that acquires information related to the operating state of the compressor and information acquired by the first temperature sensor and the second temperature sensor, a determination unit that determines that there is an abnormality in the pressure reduction mechanism when the temperature difference between the center and the outlet of the condenser when the operating state of the compressor is high falls outside an appropriate range of the temperature difference between the center and the outlet of the condenser that is predetermined based on the information acquired by the acquisition unit when the pressure reduction mechanism is normal, and an output unit that outputs information indicating the abnormality when the determination unit determines that there is an abnormality in the pressure reduction mechanism.

This technology makes it possible to detect malfunctions (abnormalities) caused by refrigerant leaks in a cooling storage facility without installing a gas detector.

FIG. 1 is a block diagram of an anomaly detection system according to an embodiment. FIG. 1 is a partially cutaway front view of a cooling storage unit according to an embodiment; FIG. 3 is a cross-sectional view showing a cooling unit of the cooling storehouse of FIG. Circuit diagram of a cooling unit for the cooling storage of FIG. Block diagram of a cooling storage facility according to an embodiment. Flow diagram of cooling operation of a cooling storage according to one embodiment Flow diagram of defrosting operation of a cooling storage according to one embodiment 1 is a flow diagram of an anomaly detection method according to an embodiment; Graph showing a schematic relationship between the ambient temperature and the compressor operation rate during cooling operation of a cooling storage facility. Graphs showing a schematic example of the compressor operation rate and the storage chamber temperature during cooling operation when a malfunction is progressing in the cooling storage. A graph showing a schematic example of the temperature difference between the storage chamber and the evaporator inlet when a malfunction of the cooling storage is progressing Graphs showing schematic examples of compressor rotation speed, storage compartment temperature, compressor operation rate, and compressor average rotation speed when a malfunction of a cooling storage is progressing

<Embodiment 1>
A detection system according to an embodiment of the present technology and its peripheral technology will be described with reference to Figures 1 to 11 as appropriate. The symbols F, Rr, L, R, U, and D shown in Figures 2 and 3 respectively indicate the front and rear in the front-rear direction of the cooling storage 10, the left and right in the width direction when viewed from the front, and the top and bottom in the vertical direction. However, the above directions are merely defined for convenience and should not be interpreted as being limiting. In addition, for multiple identical members, a symbol may be attached to one member and the symbols of the other members may be omitted.

The detection system 1 according to the present technology detects at an early stage whether the malfunction of the cooling unit is caused by a refrigerant leak in the cooling storage 10 when the cooling performance of the cooling storage 10 is degraded, without providing a special device such as a gas detector. That is, as shown in FIG. 1, the detection system 1 includes the cooling storage 10, a sensor 22T, and an information processing device 80. The detection system 1 of this embodiment additionally includes another computer 60. Below, the detection system 1 and the cooling storage 10, information processing device 80, computer program (hereinafter simply referred to as program), and detection method that constitute this detection system 1 will be described.

[Cold storage]
The cooling storage facility 10 is a storage facility for cooling foodstuffs or other storage objects while maintaining their quality, for example to a temperature suitable for frozen or refrigerated storage, and for storing the cooled objects while continuing to maintain their quality. As shown in Figures 1 and 2, the cooling storage facility 10 of this embodiment is a two-door cooling storage facility. The cooling storage facility 10 is mainly composed of a storage facility body 11 having a generally substantially rectangular parallelepiped shape, and a machine room 15 is disposed above the storage facility body 11, which is supported from below by legs 19.

The storage body 11 is equipped with a thermally insulated housing 12 with an opening on one side at the front, and a door 13. The thermally insulated housing 12 is constructed by fitting an inner box, also made of a stainless steel plate, inside an outer box made of a stainless steel plate, and filling the space between the outer box and the inner box with a thermal insulating material made of foamed resin such as urethane foam. A cooling chamber 17 is defined above the thermally insulated housing 12 by attaching a cooling chamber duct 18 (see FIG. 3). The remaining part of the inside of the thermally insulated housing 12 separated by the cooling chamber duct 18 is the storage chamber 14 for containing the storage object to be stored. An opening is provided in the upper wall of the thermally insulated housing 12, and the cooling chamber 17 and the machine room 15 are configured to be able to communicate with each other. A beam-shaped member is provided at the front ends of the left and right side walls of the thermally insulated housing 12 to separate the front opening 12A into upper and lower parts.

The door 13 is an element that opens and closes the opening 12A of the insulated housing 12. The storage chamber 14 is constructed by covering the opening 12A of the insulated housing 12 with the door 13, and the storage chamber 14 can be insulated from the outside. The door 13 is composed of two sets of single-leaf doors, and the opening 12A is opened and closed by these two doors 13. Each door 13 is attached to the right edge of the opening 12A of the insulated housing 12 so that it can be swung open and closed with the right end part as a swing axis. Each door 13 is composed of an exterior material made of stainless steel plate and an interior material made of synthetic resin, and a heat insulating material made of foamed resin such as rigid polyurethane foam is filled between them. In addition, a sealing member 35 is attached to the peripheral part of the back surface that faces the inside of the storage when the door 13 is closed. The sealing member 35 is arranged in a position interposed between the door 13 and the opening edge of the insulated housing 12 and the beam-shaped member when the door 13 is closed. The sealing member 35 is made of elastic soft synthetic resin such as rubber or elastomer resin, and provides an airtight seal between the door 13 and the insulated housing 12 when the door is closed.

In this embodiment, the storage body 11 is additionally provided with a door opening/closing sensor 34 as shown in FIG. 2. The door opening/closing sensor 34 includes a magnet 34A and a proximity switch 34B. The proximity switch 34B and the magnet 34A are an example of the door opening/closing sensor 34. The magnet 34A is embedded in the upper edge of the upper door 13 and the lower edge of the lower door 13, respectively. The proximity switch 34B is embedded in a position facing the magnet 34A when the door is closed, among the opening edges of the insulated housing 12. The proximity switch 34B in this example is a magnetically sensitive proximity switch 34B (e.g., a reed switch). The magnet 34A and the proximity switch 34B are configured such that when the door 13 is closed, the magnet 34A approaches the proximity switch 34B, and the proximity switch 34B responds to close the reed switch. This allows the closed state of the door 13 to be detected when the reed switch is closed, and the open state of the door 13 to be detected when the reed switch is open. The door open/close sensor 34 is electrically connected to the control device 50.

The machine room 15 is provided on top of the insulated housing 12. In the machine room 15, a part of the cooling unit 20 for cooling the air inside the storage room 14 (inside the storage room) and a control device 50 for controlling each part of the cooling storage room 10 are arranged. The machine room 15 and the cooling room 17 can communicate with each other through an opening, but this opening can be insulated by fitting an insulating partition plate 29 from the side of the machine room 15. The control device 50 can be electrically connected to an external power source (not shown), and for example, each part of the cooling storage room 10 is supplied with power via the control device 50.

A front panel 15A is provided in front of the machine room 15. An opening is provided in the front panel 15A, and the operation panel 16 is attached so that it is exposed to the front from the opening. The operation panel 16 is integrally equipped with a display unit (an example of an alarm means), an operation unit, and a fourth temperature sensor 16T. The display unit and operation unit of the operation panel 16, and the fourth temperature sensor 16T are electrically connected to the control device 50. The display unit of the operation panel 16 may be, for example, a seven-segment display or a liquid crystal display, and displays various information about the cooling storage 10. The display unit of the operation panel 16 is configured to be able to display, for example, information indicating the operating state of the cooling storage 10 (specifically, including codes, characters, and a user interface (UI) indicating "cooling operation" and "defrosting operation" described later), information indicating an abnormality in the cooling storage 10, and temperatures detected by each of the sensors 16T, 22T, 24T, and 26 described later. The operation section of the operation panel 16 may be, for example, a push button switch or a capacitance touch switch, and is configured to be able to instruct the control device 50 on the operating conditions of the cooling storage facility 10 and the operation of the cooling storage facility 10. The fourth temperature sensor 16T detects the temperature (ambient temperature) of the external environment in which the cooling storage facility 10 is placed. The fourth temperature sensor 16T is configured by a temperature sensor such as an NTC (negative temperature coefficient) thermistor.

The cooling unit 20 is an element that mainly cools the air in the storage room 14 to a predetermined cooling temperature. As shown in Figs. 3 and 4, the cooling unit 20 generally includes a compressor 21, a condenser 22, a condenser fan 22F, a capillary tube 23 (an example of a pressure reduction mechanism), an evaporator 24, an evaporator fan 24F, and a refrigerant pipe 25 that circulates the refrigerant. In the cooling unit 20, the compressor 21, the condenser 22, the capillary tube 23, and the evaporator 24 are connected in this order by the refrigerant pipe 25 to circulate the refrigerant, thereby forming a known refrigeration cycle. Of the cooling unit 20, the compressor 21, the condenser 22, and the condenser fan 22F are placed on a heat-insulating partition plate 29 and arranged in the machine room 15 (in other words, exposed to the outside air). Of the cooling unit 20, the evaporator 24, the evaporator fan 24F, and the capillary tube 23 are installed below the insulating partition plate 29 and disposed in the cooling chamber 17. The compressor 21, the condenser fan 22F, and the evaporator fan 24F are each electrically connected to the control device 50.

The condenser 22 is a heat exchanger that cools, condenses, and liquefies the high-pressure, high-temperature refrigerant gas that has left the compressor 21. The condenser 22 in this example is a coil-type air-cooled condenser equipped with plate fins. In the condenser 22, long pipes through which the refrigerant flows are arranged compactly in a zigzag shape. The condenser 22 includes an inlet 22A through which the refrigerant compressed by the compressor 21 is sent, an outlet 22C through which the refrigerant is sent toward the capillary tube 23, and a central portion 22B between the inlet 22A and the outlet 22C. A third temperature sensor 22T that can detect the temperature of the condenser 22 at the central portion 22B is provided on the surface of the central portion 22B of the condenser 22. The third temperature sensor 22T is composed of, for example, an NTC thermistor. The third temperature sensor 22T is electrically connected to the control device 50.

In addition, an air filter 32 is attached in front of the condenser 22. A condenser fan 22F is disposed behind the condenser 22. When the condenser fan 22F is driven, an airflow is formed from the front to the rear, cooling the condenser 22. At this time, air that has passed through the air filter 32 is sent to the condenser 22, preventing foreign matter such as dust from adhering to the plate fins of the condenser 22.

More specifically, as shown in FIG. 3, the cooling chamber duct 18 is inclined downward toward the rear, and has an intake port 18A at the front and an outlet port 18B at the rear. An evaporator fan 24F is provided above the intake port 18A, and an evaporator 24 is provided behind the evaporator fan 24F. A second temperature sensor 26 is provided in front of the evaporator 24. When the evaporator fan 24F is driven in the cooling operation, air from the storage chamber 14 is taken into the cooling chamber 17 through the intake port 18A. During the cooling operation, the second temperature sensor 26 can detect the internal temperature of the storage chamber 14. The air taken into the cooling chamber 17 is cooled by heat exchange with the evaporator 24 while passing through the evaporator 24, and is returned to the storage chamber 14 through the outlet port 18B. This allows the air in the storage chamber 14 to be cooled. The second temperature sensor 26 is, for example, an NTC thermistor. The second temperature sensor 26 is electrically connected to the control device 50.

The defrosting heater 27 is a heating means attached to the lower side of the evaporator 24 to heat and melt the frost adhering to the evaporator 24. In the cooling operation, the low-pressure refrigerant liquid decompressed by the capillary tube 23 (for example, a capillary tube) is evaporated in the evaporator 24 while absorbing the surrounding heat. At this time, the moisture contained in the air reaches the frost point by heat exchange with the evaporator 24, and frost adheres to the surface of the evaporator 24. Therefore, the defrosting heater 27 generates heat by being energized in the defrosting operation described later, which is performed between the cooling operations, and melts the frost adhering to the evaporator 24. The melted frost (moisture) falls from the evaporator 24 into the cooling chamber duct 18, and is discharged to the outside of the cooling storage 10 through the exhaust pipe 18C provided inside the back wall of the thermal insulation housing 12 by the cooling chamber duct 18. The defrosting heater 27 is composed of, for example, a sheath heater, and is arranged below the evaporator 24. The defrost heater 27 is electrically connected to the control device 50.

The evaporator 24 is configured by compactly arranging long pipes through which the refrigerant flows in a zigzag shape. A first temperature sensor 24T is installed on the refrigerant inlet side of the evaporator 24. The first temperature sensor 24T detects the temperature on the inlet side of the evaporator 24. By detecting the temperature on the inlet side of the evaporator 24 during defrosting operation using the first temperature sensor 24T, it is possible to know whether the evaporator 24 has been heated to a defrosting end temperature at which the frost attached thereto can be melted. In addition, by detecting the temperature at the inlet of the evaporator 24 during cooling operation using the first temperature sensor 24T, it is possible to know the first temperature difference described later. The first temperature sensor 24T is disposed in front of the evaporator 24, in the center part in the left-right direction, and slightly above the defrosting heater 27. The first temperature sensor 24T is configured, for example, by an NTC thermistor. The first temperature sensor 24T is electrically connected to the control device 50.

As shown in FIG. 5, the control device 50 is composed of a microcomputer having an interface (I/F) for transmitting and receiving various information, a central processing unit (CPU) for executing commands of a control program, a memory unit M for storing various information, and a timer T with a timekeeping function. The control device 50 may be composed of one or more microcomputers. The memory unit M includes a ROM (read only memory) that stores the control program executed by the CPU, and a RAM (random access memory) used as a working area for expanding the control program. The control program may be composed of one program, or may be composed of a combination of two or more programs. The memory unit M can also store various setting values required for the operation of the cooling storage facility 10.

As described above, the control device 50 is electrically connected to the compressor 21, the condenser fan 22F, the evaporator fan 24F, the defrost heater 27, and the operation panel 16. The control device 50 is also electrically connected to the first temperature sensor 24T, the second temperature sensor 26, the third temperature sensor 22T, the fourth temperature sensor 16T, and the door opening/closing sensor 34 as sensors. The control device 50 periodically or at a necessary timing monitors (detects) the evaporator temperature, the inside temperature, the condenser center temperature, the environmental temperature, and the door opening/closing state by each of the first temperature sensor 24T, the second temperature sensor 26, the third temperature sensor 22T, the fourth temperature sensor 16T, and the door opening/closing sensor 34. The control device 50 is configured to periodically or at a necessary timing transmit the information monitored (detected) by these sensors 24T, 26, 22T, 16T, and 34 to the information processing device 80 as an electrical signal through the transmission unit 56 described later.

The timing of monitoring and data transmission can be set independently for each sensor. In this example, for example, each sensor detects each physical property value at 0.1 second intervals, but is not limited thereto. Information on the detection result, together with information on the detection time, is set to be transmitted to the information processing device 80 after each detection or after multiple detections (for example, at 5 second intervals). The control device 50 is also configured to transmit other information required in the detection system 1 according to the present technology (for example, ID information of the cooling storage 10 and time information corresponding to each sensor information) to the information processing device 80 as an electrical signal via the transmission unit 56. The information sent from the cooling storage 10 to the information processing device 80 is stored in a database DB, which will be described later.

The control device 50 includes a first control unit 51 that causes the cooling storage 10 to perform a cooling operation described below, a second control unit 52 that causes the cooling storage 10 to perform a defrosting operation described below, a receiving unit 55 that receives information from an information processing device 80 described below, and a transmitting unit 56 that transmits information acquired by a sensor in the cooling storage 10. Each unit of the control device 50 may be configured by hardware including circuits such as relays, or may be functionally realized by a CPU executing software such as a cooling operation program, a defrosting operation program, a forced defrosting operation program, and a transmission/reception program. Alternatively, each of these units may be realized by cooperation between hardware and software.

[Cooling operation of cooling storage]
In the cooling storage 10, the first control unit 51 causes the cooling unit 20 to perform a cooling operation as shown in FIG. 6. The compressor 21 in this embodiment is a constant speed control compressor that has a constant rotation speed and is repeatedly operated and stopped to cool the storage chamber 14 to a predetermined temperature. In step S11, the first control unit 51 drives the compressor 21, the condenser fan 22F, and the evaporator fan 24F. At this time, the evaporator fan 24F introduces the air in the storage chamber 14 into the cooling chamber 17 and sends it to the evaporator 24. The sent air is then cooled by heat exchange with the evaporator 24 while passing through the evaporator 24, and is returned to the storage chamber 14. As a result, the air in the storage chamber 14 is cooled. In addition, the first control unit 51 measures the operation start time of the compressor 21 by a timer T in order to grasp the operating state of the compressor 21.

As shown in step S12, the first control unit 51 determines whether the current cooling operation satisfies a predetermined cooling operation end condition, in other words, a defrost start condition. If the predetermined defrost start condition is satisfied, the cooling operation is ended (END). On the other hand, if the predetermined defrost start condition is not satisfied, the process proceeds to step S13.

The defrost start condition (cooling operation end condition) can be determined as appropriate. The defrost start condition includes "the inside temperature has reached the lower limit cooling temperature at least once during the current cooling operation." The defrost start condition also includes, for example, "a certain time (for example, six hours) has passed since the current cooling operation started," "a certain time (for example, six hours) has passed since the previous defrost operation ended," "a preset time (for example, closing time) has been reached," "the cooling operation has ended (or the user has instructed to start the defrost operation)," and so on. The defrost start conditions in step S12 and step S15 described later are usually not met once during one cooling operation (NO), and the process proceeds to steps S13 and S16.

In step S13, the first control unit 51 uses the second temperature sensor 26 to determine whether the temperature of the storage chamber 14 has reached a predetermined cooling lower limit temperature. If the temperature of the storage chamber 14 has not reached the predetermined cooling lower limit temperature, the process returns to step S12 again and continues the cooling operation. On the other hand, if the temperature of the storage chamber 14 has reached the predetermined cooling lower limit temperature, the process proceeds to step S14. The cooling lower limit temperature can be, for example, a temperature slightly lower than the "cooling set temperature" of the storage chamber 14 set for the cooling operation (for example, "cooling set temperature - α1" °C). α1 can be, for example, 1.5 to 2.5 [°C], for example, 2 [°C].

In step S14, the first control unit 51 stops the drive of the compressor 21 and the condenser fan 22F, temporarily stops the cooling operation, and waits until the cooling operation is required again. The first control unit 51 also uses a timer T to measure the time when the compressor 21 stops operating in order to grasp the operating state of the compressor 21. The first control unit 51 then proceeds to step S15, and as in step S12, determines whether the specified cooling operation end condition, in other words, the defrost start condition, is satisfied for this cooling operation. If the specified defrost start condition is satisfied, the cooling operation is terminated (END). On the other hand, if the specified defrost start condition is not satisfied, the process proceeds to step S16.

In step S16, the first control unit 51 uses the second temperature sensor 26 to determine whether the temperature of the storage chamber 14 has reached a predetermined upper cooling limit temperature. If the temperature of the storage chamber 14 has not reached the predetermined upper cooling limit temperature, the process returns to step S15. If the temperature of the storage chamber 14 has reached the predetermined upper cooling limit temperature, the process proceeds to step S11 since cooling operation is required again. The upper cooling limit temperature can be, for example, a temperature slightly higher than the "cooling setting temperature" of the storage chamber 14 set for the cooling operation ("cooling setting temperature + α2" °C). α2 can be, for example, 1.5 to 2 [°C], for example 1.7 [°C].

In steps S12 and S15, the first control unit 51 repeats the operation and stopping of the compressor (steps S11 to S16) until the predetermined defrost start conditions are satisfied. Then, when the predetermined defrost start conditions are satisfied, the cooling operation is ended (END). This ends one cooling operation.

[Defrosting operation of cooling storage]
Furthermore, when the cooling unit 20 executes the cooling operation, moisture contained in the air in the storage chamber 14 is cooled by the evaporator 24, and may form frost and adhere to the surface of the evaporator 24. Therefore, the second control unit 52 of the cooling storage 10 causes the cooling unit 20 to execute a defrosting operation as shown in Fig. 7 in order to remove the frost that has adhered to the evaporator 24. Furthermore, the second control unit 52 measures the time that electricity is supplied to the defrost heater 27 by a timer T in order to measure the time required for defrosting (defrosting time).

More specifically, in step S21, the second control unit 52 energizes the defrost heater 27 while stopping the compressor 21, the condenser fan 22F, and the evaporator fan 24F. This causes the defrost heater 27 to generate heat, and the evaporator 24 and the frost are heated by the thermal conduction, melting the frost adhering to the evaporator 24. The second control unit 52 also uses a timer T to detect the time when the defrost heater 27 starts to be energized.

In step S22, the second control unit 52 determines whether the temperature of the evaporator 24 measured by the first temperature sensor 24T has reached a preset defrost end temperature. If the temperature of the evaporator 24 has not reached the predetermined defrost end temperature, the defrosting is continued. If the temperature of the evaporator 24 has reached the predetermined defrost end temperature, the process proceeds to step S23.

The defrost end temperature can be determined as the temperature at which the evaporator 24 can melt the frost that has adhered thereto, and can be determined, for example, taking into consideration the "cooling set temperature" in the cooling operation (i.e., the cooling temperature of the storage chamber 14). As an example, when the cooling set temperature is about -15 to -20°C, the defrost end temperature can be set to a temperature of about 13 to 20°C (e.g., 13°C), and when the cooling set temperature is about 3 to 5°C, the defrost end temperature can be set to a temperature of about 30 to 35°C (e.g., 30°C).

In step S23, the second control unit 52 stops the power supply to the defrost heater 27. The melt water generated by melting the frost during the defrosting operation is received by the cooling chamber duct 18 and sent to a discharge pipe (not shown) provided inside the back wall, and is discharged to the outside of the storage body 11. If the next cooling operation starts before this melt water is discharged, the melt water will freeze on the cooling chamber duct 18, reducing the heat exchange efficiency of the cooling operation. Therefore, in steps S23 and S24, the second control unit 52 waits for a predetermined time to discharge the melt water outside the storage. This waiting will be referred to as "draining water" hereinafter. The second control unit 52 also uses a timer T to detect the time when power supply to the defrost heater 27 is stopped.

Then, in step S24, the second control unit 52 determines whether the draining time measured by the timer T has reached a preset draining end time. The draining end time can be set appropriately depending on the size of the cooling chamber duct 18, etc., and can be, for example, 5.5 minutes or 10 minutes. If the draining end time has not been reached, draining continues in step S24. On the other hand, if the draining time has reached the preset draining end time, the defrosting operation ends (END). This ends one defrosting operation.

[Information processing device]
Next, the configuration of the information processing device 80 will be described. The information processing device 80 is a device for monitoring the operation of the cooling storage 10 and detecting a malfunction of the cooling storage 10 being monitored at an early stage. The information processing device 80 can be connected to the cooling storage 10 by wire or wirelessly, for example, as shown in FIG. 1. The information processing device 80 can be connected to various computers 60, such as a portable terminal 60A and a personal computer 60B, that are permitted to be connected, in addition to the cooling storage 10, by wire or wirelessly. The information processing device 80 may be, for example, an edge computer, a cloud server, or the like.

The information processing device 80 is composed of a microcomputer having an interface (I/F) for transmitting and receiving various information, a central processing unit (CPU) as a processor P for executing instructions of a control program, a memory unit JM for storing various information, and a timer JT having a timekeeping function. The information processing device 80 may be composed of one or more microcomputers. The memory unit JM includes a ROM (read only memory) that stores the control program executed by the CPU, and a RAM (random access memory) used as a working area for expanding the control program. The control program may be composed of one program, or may be composed of a combination of two or more programs. The memory unit JM also includes a database DB for storing and storing the measurement data transmitted from the cooling storage 10.

The information processing device 80 includes an acquisition unit 81, a judgment unit 86, and an output unit 87. The information processing device 80 additionally includes a first appropriate range determination unit 82, a second appropriate range determination unit 83, a third appropriate range determination unit 84, and a fourth appropriate range determination unit 85. Each of the units 81 to 87 included in the information processing device 80 may be configured by hardware including circuits such as relays, or may be functionally realized by a CPU executing one or more control programs. Alternatively, each of these units may be realized by a combination of hardware and software.

The acquisition unit 81 acquires information regarding the operating state of the compressor 21 and information detected by the first temperature sensor 24T, the second temperature sensor 26, the third temperature sensor 22T, the fourth temperature sensor 16T, and the door opening/closing sensor 34. The acquisition unit 81 may acquire information regarding the operating state of the compressor 21 directly from the cooling storage facility 10, or may acquire information sent from the cooling storage facility 10 and stored in the database DB. The same applies below when each unit of the information processing device 80 acquires various types of information.

The first optimum range determination unit 82 determines a "first optimum range" indicating an optimum range for the operation state of the compressor 21 based on information acquired by the acquisition unit 81 regarding the operation state of the compressor 21 during cooling operation when the cooling storage facility 10 is normal. The first optimum range is, for example, an optimum range of the operation rate of the compressor 21 during cooling operation of the cooling storage facility 10. The operation rate of the compressor 21 can be grasped, for example, as the time obtained by subtracting the operation start time from the operation stop time detected by the timer T. The optimum range of the operation rate of the compressor 21 can be determined for each environmental temperature. It is detected by measuring. The environmental temperature is detected by the fourth temperature sensor 16T.

The second optimum range determination unit 83 determines a "second optimum range" indicating the optimum range of the temperature difference between the central part 22B of the condenser 22 and the ambient temperature (hereinafter sometimes referred to as the second temperature difference) based on information regarding the temperature of the central part 22B of the condenser 22 and the ambient temperature during cooling operation when the cooling storage facility 10 is normal, acquired by the acquisition unit 81. The temperature of the central part 22B of the condenser 22 is detected by the third temperature sensor 22T. The ambient temperature is detected by the fourth temperature sensor 16T.

The third optimum range determination unit 84 determines a "third optimum range" indicating an optimum range of the defrost time based on information acquired by the acquisition unit 81 regarding the time during which the defrost heater 27 is energized during defrosting operation when the cooling storage unit 10 is normal. The defrost time can be understood as the time obtained by subtracting the start time of energization from the stop time of energization of the defrost heater 27, which is measured by a timer and detected by the timer.

The fourth optimum range determination unit 85 determines a "fourth optimum range" that indicates the optimum range of the temperature difference (first temperature difference) between the inside temperature during defrosting operation and the inlet temperature of the evaporator 24 when the cooling storage unit 10 is normal, as acquired by the acquisition unit 81. The inside temperature during defrosting operation is detected by the second temperature sensor 26. The inlet temperature of the evaporator 24 is detected by the first temperature sensor 24T.

The determination unit 86 makes the following four determinations as shown in Fig. 8 based on information on the first to fourth appropriate ranges determined by the first to fourth appropriate range determination units 82 to 85, information on the driving state of the compressor 21, and information detected by the first temperature sensor 24T, the second temperature sensor 26, the third temperature sensor 22T, and the fourth temperature sensor 16T. The determination unit 86 then determines that there is a refrigerant leak when a determination condition is met in at least the following determination 4, which includes a condition that the first temperature difference falls outside the appropriate range. In this embodiment, it is determined that there is a refrigerant leak when the determination results of these determinations 1 to 4 satisfy predetermined conditions.
(Decision 1) Whether the driving state of the compressor 21 is higher than the appropriate range. (Decision 2) Whether the temperature difference (second temperature difference) between the central portion 22B of the condenser 22 and the ambient temperature is larger than the appropriate range. (Decision 3) Whether the time required for defrosting is longer than the appropriate range. (Decision 4) Whether the temperature difference (first temperature difference) between the inside temperature and the inlet temperature of the evaporator 24 during defrosting operation is larger than the appropriate range.

If there is any abnormality in the cooling storage facility 10 based on the results of judgments 1 to 4 made by the judgment unit 86, the output unit 87 outputs information indicating the abnormality. The information indicating the abnormality by the output unit 87 may be output to the cooling storage facility 10, to another computer 60, to a database DB, or to one or more of these. The information indicating the abnormality may simply be information indicating that there is an abnormality, or may be information indicating a prompt to properly recover from the abnormality.

[Detection method]
Next, a general flow of the detection method according to the present technology will be described with reference to Fig. 8 to Fig. 11. That is, the detection method according to the present technology includes the following steps.
Step 1: Acquire normal data of the cooling storage unit. Step 2: Decide on the first to fourth optimum ranges. Step 3: Acquire operation data of the cooling storage unit to be evaluated. Step 4: Determine the cause of a problem with the cooling storage unit (steps S41, S42, S44, and S46 in FIG. 8).
Step 5: Output the cause of the malfunction of the cooling storage (steps S43, S45, S47, and S48 in FIG. 8)

1. Acquisition of normal data of the cooling storage First, the cooling storage 10 performs a cooling operation (see FIG. 6) and a defrosting operation (see FIG. 7) when the cooling storage 10 is in a normal state. The cooling operation and the defrosting operation may be repeated until data necessary for determining the first to fourth appropriate ranges are acquired. At this time, the cooling storage 10 monitors the state of the cooling storage 10 using the timer T, the first temperature sensor 24T, the second temperature sensor 26, the third temperature sensor 22T, and the fourth temperature sensor 16T, and transmits the monitored (detected) information to the information processing device 80 as an electric signal through the transmission unit 56. As a result, the information processing device 80 acquires the monitoring information sent from the cooling storage 10 by the acquisition unit 81 and stores it in the database DB (step 1).

In this embodiment, the cooling storage unit 10 being in a normal state means that the cooling storage unit 10 is in a state in which there are no defects that impair the cooling performance. Specific examples of a cooling storage unit 10 in a normal state include a cooling storage unit that has been in a normal state for several weeks or one month since the date on which the cooling storage unit 10 was first used, or a cooling storage unit that has been in a normal state for several weeks or one month since the date on which a service technician performed maintenance (cleaning, replacement, etc.) on the cooling unit 20.

2. Determination of the First to Fourth Optimum Ranges If any malfunction occurs in the cooling storage cabinet 10, the cooling performance will decrease. There are various possible causes of the malfunction in the cooling unit 20. Therefore, in this technology, the cause of the malfunction in the cooling storage cabinet 10 is identified from the cause of the malfunction and the phenomenon that appears in the cooling unit 20 as a result of the malfunction.

[First optimum range: compressor operation rate]
When the cooling performance of the cooling storage 10 is reduced, the cooling efficiency of the storage chamber 14 is reduced, and therefore, for example, the operating state of the compressor 21 when cooling the storage chamber 14 to a predetermined temperature is increased. Whether the operating state of the compressor is increased can be grasped, for example, by whether the relationship between the environmental temperature and the operating rate of the compressor 21 is within an appropriate range. For the cooling storage 10, as shown in FIG. 9, for example, the higher the environmental temperature (more specifically, the larger the temperature difference between the environmental temperature and the cooling set temperature of the storage chamber 14), the larger the load required for heat exchange becomes, and therefore the operating rate of the compressor 21 becomes higher. If the environmental temperature (or the temperature difference between the environmental temperature and the cooling set temperature of the storage chamber 14) is constant, when the cooling storage 10 is normal (shown by a thick line in FIG. 9), the compressor 21 is operated at a relatively low operating rate, whereas when the cooling storage 10 has a malfunction and the cooling performance is reduced (shown by a thin line in FIG. 9), the operating rate of the compressor 21 becomes relatively high. Therefore, in this example, an appropriate range (first appropriate range) of the operation rate of the compressor 21 with respect to the environmental temperature (or the temperature difference between the environmental temperature and the cooling set temperature of the storage chamber 14) when the cooling storage chamber 10 is normal is checked in advance, and when the operation rate is higher than this first appropriate range, it can be determined that the operation state of the compressor 21 is increased (i.e., the cooling performance of the cooling storage chamber 10 is degraded). In this way, the operation rate (%) of the compressor 21 during cooling operation can be preferably used as information representing the operation state of the compressor 21 in this embodiment.

The first appropriate range determination unit 82 determines the appropriate range of the operation rate (%) of the compressor 21 during cooling operation based on, for example, the operation time and stop time of the compressor 21 during cooling operation measured by the timer T acquired by the acquisition unit 81. Specifically, for example, the first appropriate range determination unit 82 first determines a reference operation rate that is the basis of the operation rate of the compressor 21 during cooling operation for each individual cooling storage, and then determines the range of the appropriate operation rate based on this reference operation rate. The appropriate operation rate of the compressor 21 may differ depending on the temperature difference between the environmental temperature and the cooling set temperature of the storage chamber 14 (i.e., the cooling temperature range). Therefore, the first appropriate range may be determined for each temperature difference between the environmental temperature and the cooling set temperature of the storage chamber 14 (i.e., the cooling temperature range). For example, the environmental temperature at the start of each cooling operation can be used as the environmental temperature when calculating the operation rate. Information regarding the calculated appropriate operation rate is stored in the memory unit JM.

The reference operation rate can be, for example, the average operation rate of the compressor 21 obtained for multiple cooling operations performed when the cooling storage 10 is normal. The operation rate of the compressor 21 can be calculated for each cooling operation, for example, based on the following formula: operation rate (%) = (operation time of the compressor during cooling operation) ÷ (operation time of the compressor during cooling operation + stop time of the compressor during cooling operation) × 100. The operation time and stop time can be calculated, for example, based on information regarding the operation time and stop time of the compressor 21 during the cooling operation.

Next, the first appropriate range determination unit 82 determines a first appropriate range, which is a range that can be considered as an appropriate operation rate of the compressor 21, based on the standard operation rate. The appropriate range of the operation rate can be determined, for example, by setting a threshold value for the standard operation rate, and being equal to or less than this threshold value, or not exceeding this threshold value. One of the conditions for determining that the operation rate of the compressor 21 is not appropriate is when the operation rate becomes significantly high. For example, the operation rate of the compressor 21 becomes significantly high when it exceeds the standard operation rate by +3%, for example, when it exceeds +5%. The operation rate of the compressor 21 is characterized by being easily fluctuated due to the influences of the environmental temperature, voltage fluctuations, door opening and closing, load temperature inside the storage unit, etc. Therefore, it is advisable to periodically (e.g., daily) monitor the increase in the standard operation rate (e.g., 50%) and, after confirming that the increase increases stepwise and sequentially over multiple consecutive observations, such as +1%, +3%, +5%, etc., it is possible to determine that the operation rate of the compressor 21 is on the rise when the increase exceeds the first appropriate range (e.g., (50+5)%).

The second to fourth optimum ranges can be determined in the same way as the first optimum range. That is, a reference value that serves as the basis for each optimum range and a threshold value that indicates the tolerance for this reference value are set, and each optimum range can be determined as being equal to or less than this threshold value, or not exceeding the threshold value. Below, the method for determining the second to fourth optimum ranges is explained, but explanations of parts that overlap with the method for determining the first optimum range will be omitted.

[Second optimum range: temperature difference between the center of the condenser and the ambient temperature (second temperature difference)]
When a malfunction occurs in the cooling storage 10, clogging of the air filter 32 is considered as one of the causes of the malfunction. For example, when clogging occurs in the air filter 32, the time required to cool the temperature of the storage chamber 14 to a predetermined cooling set temperature becomes longer. When clogging occurs in the air filter 32, the air that can pass through the air filter 32 decreases, making it difficult for the condenser 22 to be air-cooled, and the cooling performance of the cooling storage 10 decreases. Therefore, when the temperature of the condenser 22 relative to the environmental temperature, more specifically, the temperature difference (second temperature difference) between the environmental temperature and the temperature of the central part 22B of the condenser 22 becomes larger than normal, it is considered that clogging has occurred in the air filter 32. Therefore, the second appropriate range, which is the appropriate range of the second temperature difference, can be, for example, a reference temperature difference that is the average of the second temperature difference during cooling operation when the cooling storage 10 is normal, and is +8°C or less of this reference temperature difference. At this time, the increase in the second temperature difference from the reference temperature difference is monitored periodically (e.g., daily), and the increase is confirmed to increase stepwise and sequentially in a number of consecutive observations, for example, +6.5°C, +7.2°C, +7.9°C, +8.2°C, etc., and when the increase exceeds an appropriate range (reference temperature difference +8°C in this case), it can be determined that the second temperature difference is on the rise. Also, when the increase in the second temperature difference is unchanged or on the decline, it can be determined that the second temperature difference is not on the rise. By determining the appropriate range of the second temperature difference in this way, it is possible to clarify the criteria for determining whether the air filter 32 is clogged, and to improve the accuracy of determining whether the filter is clogged.

[Third optimum range: defrosting time, fourth optimum range: first temperature difference]
When a malfunction occurs in the cooling storage 10, one of the possible causes of the malfunction is a leak of refrigerant gas or an abnormality in the sealing member 35. For example, when a refrigerant leak occurs, a refrigerant shortage occurs, and while the temperature at the inlet side of the evaporator 24 drops sufficiently during cooling operation, the temperature at the outlet side of the evaporator 24 does not drop sufficiently. If the entire evaporator 24 is not sufficiently cooled, the air in the storage chamber 14 cannot be sufficiently cooled, and the temperature difference (first temperature difference) between the temperature at the inlet side of the evaporator 24 and the temperature inside the chamber becomes larger than when there is no refrigerant shortage. As shown in FIG. 11, this first temperature difference becomes larger as the refrigerant leak progresses. In addition, this first temperature difference becomes larger in response to the degree of abnormal frosting even when abnormal frosting occurs on the evaporator 24 due to a decrease in the airtightness of the sealing member 35. However, when abnormal frosting occurs, another characteristic is observed in that the defrosting time in the defrosting operation becomes longer. In addition, when only refrigerant leakage or abnormal frosting occurs, the second temperature difference is in the second appropriate range. Therefore, by checking whether the defrosting time is within an appropriate range and whether the first temperature difference is within an appropriate range, it is possible to determine whether the cause of the malfunction in the refrigerated storage cabinet 10 is a refrigerant leak or an abnormality in the sealing member 35. When a malfunction occurs in the refrigerated storage cabinet 10 and it is considered that there is no problem with any of the clogging of the air filter 32, the refrigerant leak, and the abnormality in the sealing member 35, it can be considered that the cause is an abnormality in the compressor 21.

The third appropriate range indicating the appropriate range of the defrost time can be, for example, the average of the energization time of the defrost heater 27 during the defrost operation when the cooling storage 10 is normal as the reference defrost time, and the reference defrost time difference can be +30 minutes. At this time, the increase in the energization time relative to the reference defrost time is monitored, and it is confirmed that the increase increases stepwise and sequentially in multiple consecutive observations, for example, +16 minutes, +21 minutes, +27 minutes, +32 minutes, etc., and when it exceeds the appropriate range (in this case, the reference defrost time +30 minutes), it can be determined that the defrost time is tending to increase. Also, when the increase in the energization time is unchanged or tends to decrease, it can be determined that the defrost time is not tending to increase. By determining the appropriate range of the defrost time in this way, it is possible to clarify the criteria for determining whether abnormal frost has occurred in the evaporator 24, and by extension, whether there is an abnormality in the sealing member 35.

The fourth appropriate range, which is the appropriate range of the first temperature difference, can be, for example, within +8°C of the reference temperature difference, with the average of the first temperature difference during cooling operation when the cooling storage 10 is normal. At this time, the increase in the first temperature difference from the reference temperature difference is periodically (for example, once a day) monitored, and the increase is confirmed to increase stepwise and sequentially in multiple consecutive observations, for example, +5.5°C, +6.2°C, +7.5°C, +8.2°C, etc., and when it exceeds the appropriate range (in this case, the reference temperature difference +8°C), it can be determined that the first temperature difference is on the rise. Note that when the increase in the first temperature difference is unchanged or on the decline, it can be determined that the first temperature difference is not on the rise. By determining the appropriate range of the first temperature difference in this way, it is possible to clarify the criteria for determining whether a refrigerant leak or an abnormality in the sealing member 35 has occurred.

The first to fourth appropriate ranges determined by the first to fourth appropriate range determination units 82 to 85, respectively, are stored in the storage unit JM (step 2). However, the first to fourth appropriate ranges may use values previously stored in the storage unit JM.

3. Acquisition of operation data of the cooling storage After the appropriate range is determined in the above step 2, the cooling storage 10 continues to perform the cooling operation (see FIG. 6) and the defrosting operation (see FIG. 7). The cooling operation and the defrosting operation are repeatedly performed until the operation of the cooling storage 10 is terminated. The cooling storage 10 monitors the state of the cooling storage 10 using the timer T, the first temperature sensor 24T, the second temperature sensor 26, the third temperature sensor 22T, and the fourth temperature sensor 16T, and transmits the monitored (detected) information to the information processing device 80 as an electric signal through the transmission unit 56. As a result, the information processing device 80 acquires the monitoring information sent from the cooling storage 10 by the acquisition unit 81 and stores it in the database DB. More specifically, the acquisition unit 81 acquires data used to determine the appropriate range, such as the start and end times of operation of the compressor 21, the start and end times of power supply to the defrost heater 27, the temperature on the inlet side of the evaporator 24, the temperature inside the cabinet, the temperature of the central part 22B of the condenser 22, and information regarding the ambient temperature (step 3).

4. Determination of the cause of a malfunction in the cooling storage Next, the determination unit 86 performs four determinations, (Determination 1) to (Determination 4), to determine whether the cause of the malfunction in the cooling storage 10 is a clogged air filter 32, an abnormality in the sealing member 35, a refrigerant leak, or an abnormality in the compressor 21. More specifically, as shown in FIG. 8, in step S41, the determination unit 86 first determines whether the driving condition of the compressor 21 is increasing, in other words, whether the cooling storage 10 is malfunctioning, based on the operation rate of the compressor 21 during the cooling operation calculated from information on the operation time and stop time of the compressor 21 during the cooling operation measured by the timer T. The calculation of the operation rate of the compressor 21 can be performed, for example, in parallel with the cooling operation by the cooling storage 10. Then, as soon as the cooling operation is completed, the determination unit 86 determines whether the calculated operation rate of the compressor 21 is within the first appropriate range stored in the memory unit JM. When the operation rate of the compressor 21 is within the first optimum range, it is determined that the driving condition of the compressor 21 is not increasing (NO in step S41), and the process proceeds to step S41 again. When the operation rate of the compressor 21 is outside the first optimum range, it is determined that the driving condition of the compressor 21 is increasing (YES in step S41), and the process proceeds to step S42.

In step S42, the determination unit 86 determines whether the second temperature difference is increasing, in other words, whether the air filter 32 is clogged, based on the second temperature difference calculated from the information detected by the third temperature sensor 22T and the fourth temperature sensor 16T. The calculation of the second temperature difference can be performed, for example, as soon as the information detected by the third temperature sensor 22T and the fourth temperature sensor 16T is received from the cooling storage 10. Then, as soon as the cooling operation is completed, the determination unit 86 determines whether the calculated second temperature difference is within the second appropriate range stored in the memory unit JM. If the second temperature difference is within the second appropriate range, it determines that the second temperature difference has not increased (NO in step S42) and proceeds to step S44. If the second temperature difference is outside the second appropriate range, it determines that the air filter 32 is clogged (YES in step S42) and proceeds to step S43.

In step S44, the determination unit 86 determines whether the defrost time has increased, in other words, whether there is an abnormality in the sealing member 35, based on the defrost time calculated from the information on the start and stop times of the defrost heater 27 detected by the timer T. The calculation of the defrost time can be performed, for example, as soon as information on the start and stop times of the defrost heater 27 is received from the cooling storage 10. The calculation result of the defrost time is stored in the memory unit JM. Then, the determination unit 86 determines whether the calculated defrost time is within the third appropriate range stored in the memory unit JM. If the defrost time is within the third appropriate range, it determines that the defrost time has not increased (NO in step S44) and proceeds to step S46. If the defrost time is outside the third appropriate range, it determines that there is an abnormality in the sealing member 35 (YES in step S44) and proceeds to step S45. The judgment in step S44 (judgment 3) is made based on information about the defrosting operation, unlike the other judgments in steps S41, S42, and S46 (judgments 1, 2, and 4) which are made based on information about the cooling operation. Therefore, the judgment unit 86 can make the judgment in step S44 by referring to the calculation result of the defrosting time calculated for the previous defrosting operation and stored in the memory unit JM.

In step S46, the determination unit 86 determines whether the first temperature difference is increasing, in other words, whether a refrigerant leak is occurring, based on the first temperature difference calculated from information on the inlet temperature of the evaporator 24 detected by the first temperature sensor 24T and the inside temperature detected by the second temperature sensor 26. The calculation of the first temperature difference can be performed, for example, as soon as information on the inlet temperature of the evaporator 24 and the inside temperature is received from the cooling storage 10. Then, as soon as the cooling operation is completed, the determination unit 86 determines whether the calculated first temperature difference is within the fourth appropriate range stored in the memory unit JM. If the first temperature difference is within the fourth appropriate range, it determines that the first temperature difference is not increasing (NO in step S46) and proceeds to step S48. If the first temperature difference is outside the fourth appropriate range, it determines that a refrigerant leak is occurring (YES in step S46) and proceeds to step S47.

5. Output of Cause of Malfunction of Cooling Storage The output unit 87 outputs information on the malfunction when the cooling storage 10 has some malfunction as a result of the four types of judgment by the judgment unit 86. Specifically, the output unit 87 outputs information indicating that the air filter 32 is clogged in step S43. The output unit 87 also outputs information indicating that the sealing member 35 has an abnormality in step S45. The output unit 87 outputs information indicating that there is a refrigerant leak in step S47. The output unit 87 outputs information indicating that there is a malfunction in the compressor 21 in step S48. The output unit 87 can output information on these malfunctions to, for example, the cooling storage 10 or another computer 60. The cooling storage 10 or another computer 60 can also execute a notification step (not shown) of notifying that the above malfunction may occur based on the information output by the information processing device 80. Examples of the notification process in the cooling storage facility 10 include display using characters, UI, light, etc. on the display unit of the operation panel 16, notification using a sound device such as a buzzer (not shown), etc. Examples of the notification process in the other computer 60 include display using characters, UI, light, etc. on the display unit such as a display provided in the other computer 60, notification using a sound device such as a buzzer, notification using a communication application such as email or SNS (Social Networking Service), etc. This allows the user to know at an early stage that there is a possibility that a malfunction has occurred in the cooling storage facility 10, for example.
(S45, S47, S48 in FIG. 8)

Even if it is determined that a malfunction has occurred in the cooling storage 10, it is not necessary to stop the operation of the cooling storage 10 for that reason. Therefore, after the output unit 87 outputs information indicating a malfunction, as shown in step S49, the process proceeds to step S41, and the determination steps S41 to S49 for the next cooling operation are continued.

The actions and effects of this embodiment will be described below.
The above detection system 1 includes a cooling storage facility 10, a sensor, and an information processing device 80. The cooling storage facility 10 includes a storage facility main body 11 having a storage chamber 14, a cooling unit 20 including a compressor 21, a condenser 22, a capillary tube 23, an evaporator 24, a refrigerant pipe 25 for circulating a refrigerant through these, and a defrost heater 27 for heating the evaporator 24, a first temperature sensor 24T capable of detecting the temperature of the evaporator 24 at the inlet of the evaporator 24, and a second temperature sensor 26 capable of detecting the temperature inside the facility, and further includes a means for performing a cooling operation in which air from the storage chamber 14 is taken into the cooling unit 20, cooled, and then returned to the storage chamber 14, a transmitting unit 56 for transmitting information regarding the operating state of the compressor 21 and information acquired by the first temperature sensor 24T and the second temperature sensor 26 to an information processing device 80 connected to the information processing device so as to be able to communicate with the information processing device 80, a receiving unit 55 for receiving information indicating the abnormality from the information processing device 80 when the information processing device 80 determines that there is a refrigerant leak, and an operation panel 16 for reporting the abnormality based on the received information. The information processing device 80 includes an acquisition unit 81 that acquires information regarding the operating state of the compressor 21 and information acquired by the first temperature sensor 24T and the second temperature sensor 26, a judgment unit 86 that judges that there is a refrigerant leak when a first temperature difference, which is the temperature difference between the internal temperature and the temperature at the inlet of the evaporator 24 when the operating state of the compressor 21 is increasing, falls outside an appropriate range of the temperature difference between the internal temperature and the inlet of the evaporator 24, which is predetermined based on the information acquired by the acquisition unit 81 when there is no refrigerant leakage from the refrigerant pipe 25, and an output unit 87 that outputs information indicating an abnormality when the judgment unit 86 judges that there is a refrigerant leak.

According to this embodiment 1, the temperature difference (first temperature difference) between the inlet temperature of the evaporator 24 and the temperature inside the storage is monitored, an appropriate range is set, and it is determined whether the first temperature difference is appropriate, thereby estimating whether the cause of a malfunction in the cooling storage storage 10 is due to a refrigerant leak. This makes it possible to detect a malfunction in the cooling storage storage caused by a refrigerant leak. Furthermore, when a malfunction occurs in the cooling storage storage, it is possible to estimate whether the cause is due to a refrigerant leak. In particular, it is possible to determine whether the cause of a malfunction in the cooling storage storage 10 is due to a refrigerant leak without using special equipment such as a gas detector.

In embodiment 1, the condenser 22 includes an inlet 22A through which the refrigerant compressed by the compressor 21 is sent, an outlet 22C through which the refrigerant is sent toward the capillary tube 23, and a central portion 22B between the inlet 22A and the outlet 22C, and the cooling storage tank 10 further includes a third temperature sensor 22T capable of detecting the temperature of the condenser 22 in the central portion 22B of the condenser 22, and a fourth temperature sensor 16T capable of detecting the temperature of the environment in which the cooling storage tank 10 is installed. The acquisition unit 81 acquires information detected by the third temperature sensor 22T and the fourth temperature sensor 16T, and the judgment unit 86 is further configured to judge that a refrigerant leak has occurred when the second temperature difference, which is the temperature difference between the environmental temperature and the temperature of the central part 22B of the condenser 22 when the driving state of the compressor 21 is increasing, falls outside the appropriate range of the temperature difference between the environmental temperature and the temperature of the central part 22B of the condenser 22, which is predetermined based on the information acquired by the acquisition unit 81 when there is no refrigerant leakage from the refrigerant pipe 25.

When a refrigerant leak occurs, the operation rate of the compressor 21 is increased to lower the temperature of the storage chamber 14 compared to when there is no refrigerant leak. Here, as the refrigerant gas decreases, the temperature of the central portion 22B of the condenser 22 is less likely to increase, and the temperature difference between the ambient temperature and the temperature of the central portion 22B of the condenser 22 may be smaller than when there is no refrigerant gas leak. With the above configuration, it is possible to determine whether a refrigerant leak has occurred by taking into account the second temperature difference, which is the temperature difference between the ambient temperature and the temperature of the central portion 22B of the condenser 22. This makes it possible to more accurately detect malfunctions in the cooling storage facility 10 caused by refrigerant leaks.

In the first embodiment, the cooling unit 20 further includes a defrost heater 27 (an example of a heater) for heating the evaporator 24, and the cooling storage 10 includes a configuration for performing a defrost operation in which the defrost heater 27 heats the evaporator 24 to melt frost adhering to the evaporator 24 when a predetermined defrosting condition is satisfied, and a timer T for detecting the time required for the defrost operation. The acquisition unit 81 acquires information regarding the time required for the defrost operation detected by the timer T, and the determination unit 86 is further configured to determine that there is a refrigerant leak when the time required for the most recently performed defrost operation falls outside the appropriate range of the time required for the defrost operation that is predetermined based on the information acquired by the acquisition unit 81 when there is no refrigerant leak from the refrigerant pipe 25.

The first temperature difference may also be large when excessive frost is present on the evaporator 24 of the cooling storage 10. The amount of frost present on the cooling storage 10 roughly corresponds to the length of the defrosting operation required to melt the frost, and whether or not excessive frost is present on the evaporator 24 can be determined by the time required for the defrosting operation. With the above configuration, whether or not excessive frost is present on the evaporator 24 is determined from the time of the most recently performed defrosting operation, and if excessive frost is present on the evaporator 24, a determination as to whether or not a refrigerant leak has occurred is not made even if the first temperature difference is outside the appropriate range. This makes it possible to more accurately detect malfunctions in the cooling unit caused by refrigerant leakage.

<Embodiment 2>
In the above-mentioned first embodiment, the door open/close sensor 34 was an additional element, but in the second embodiment, the door open/close sensor 34 is provided in the cooling storage cabinet 10 as an essential element. The first appropriate range determiner 82 may adopt one or more of the following conditions (a) to (e) when determining the first appropriate range. The other configurations may be the same as those in the first embodiment, and a description of the similar configurations, actions, and effects will be omitted.

[conditions]
(a) Information about the cooling operation detected within a specified time after the defrosting operation is not used. (b) When the fluctuation in the compressor operation rate in multiple consecutive cycles falls within a specified range, the average value of the operation rates in the multiple consecutive cycles is adopted as the average operation rate of the compressor for one cooling operation, and an appropriate range is determined. (c) When the fluctuation in the compressor operation rate in multiple consecutive cycles falls within a specified range, the average value of the operation rates in the multiple consecutive cycles is adopted as the average operation rate of the compressor for one cooling operation, and an appropriate range is determined. (d) When the door is opened or closed during multiple consecutive cycles, compensation is performed to prevent the operation rate from being increased due to the door opening or closing. (e) When the door is opened or closed during multiple consecutive cycles, information about the cooling operation detected during the multiple consecutive cycles is not used.

[Condition (a)]
Immediately after the end of the defrosting operation, the temperature of the cooling chamber 17 rises to near the defrosting end temperature, and it may be difficult for the second temperature sensor 26 to accurately detect the temperature of the air in the storage chamber 14. The cooling operation includes a cooling period in which the air in the storage chamber 14 is cooled from near the defrosting end temperature to near the cooling set temperature, and a cold storage period in which the air in the storage chamber 14 is maintained near the cooling set temperature. Since the compressor 21 is operated continuously during the cooling period, if the operation time of the compressor 21 during the cooling period is included in the calculation of the operation rate of the compressor 21, the reference operation rate and the appropriate range of the operation rate become higher, and the influence of a decrease in the performance of the cooling unit 20 is less likely to appear in the operation rate of the compressor 21. Therefore, when determining the appropriate range of the operation rate of the compressor, it is preferable not to use data indicating the operation status of the cooling storage 10 acquired within a predetermined time (typically 30 minutes to 1.5 hours, for example 1 hour) after the defrosting operation. This can increase the accuracy of the appropriate range of the operation rate of the compressor.

[Condition (b)]
The operation rate of the compressor 21 is characterized by being easily fluctuated in a short period of time due to external factors such as environmental temperature, voltage fluctuation, door opening and closing, and load temperature inside the refrigerator. In addition, such factors that cause fluctuations in the operation rate of the compressor 21 tend to occur frequently. Therefore, the operation rate of the compressor in one cooling operation can be adopted as a representative value of the compression rate for a part of a period in which the operation rate of the compressor 21 does not fluctuate significantly. For example, in a cooling operation, when a period in which the temperature inside the refrigerator is controlled from one cooling upper limit temperature (or cooling lower limit temperature) to the next cooling upper limit temperature (or cooling lower limit temperature) is defined as one cycle, if the fluctuation of the operation rate of consecutive multiple cycles (e.g., three cycles) is small (e.g., within ±3% of the average value, e.g., 47 to 53%), the average operation rate of the multiple cycles can be adopted as the average operation rate for the single cooling operation. When there are multiple cycles in which the fluctuation of the operation rate is small, the average operation rate of any consecutive multiple cycles among them can be adopted as the average operation rate of the cooling operation.

[Condition (c)]
Since the temperature difference between the environmental temperature and the cooling set temperature of the storage chamber 14 (i.e., the cooling temperature range) differs when the environmental temperature differs, the suitable range of the operation rate of the compressor 21 is determined for each environmental temperature. Here, if the environmental temperature associated with the operation rate of the compressor 21 fluctuates greatly during the calculation of the operation rate, the accuracy of the correspondence between the operation rate and the environmental temperature may decrease. Therefore, the operation rate of the compressor in one cooling operation can be a representative value of the compression rate calculated for a part of a period in which the environmental temperature does not fluctuate greatly. For example, when the fluctuation of the environmental temperature in consecutive multiple cycles (e.g., three cycles) is small (e.g., within ±2°C of the average temperature), the average operation rate of the multiple cycles may be adopted as the average operation rate for the one cooling operation. In addition, in the above condition (b), when there are multiple sets of multiple cycles in which the fluctuation of the operation rate is small, it is more preferable to adopt the average operation rate of the multiple cycles that satisfy the condition (c) as the average operation rate of the one cooling operation. The environmental temperature can be detected by the fourth temperature sensor 16T.

[Condition (d)]
When the door 13 is opened and closed during the cooling operation, the temperature of the storage chamber 14 rises significantly, and the operation rate of the compressor 21 is increased compared to when the door is not opened and closed. Therefore, when the door 13 is opened and closed, the increase in the operation rate caused by the opening and closing of the door 13 may be compensated for when calculating the operation rate of the compressor 21. Here, compensation refers to a process of shortening the "operation time of the compressor 21" used in the calculation of the first appropriate range so that the calculated compression rate is lowered by the amount of the increase in the actual operation rate of the compressor 21 due to the opening and closing of the door. Specifically, for example, the operation rate of the compressor 21 is calculated by subtracting "the number of times the door is opened and closed x the compensation time" from the operation time of the compressor 21. As the compensation time, the time by which the operation time of the compressor increases per opening and closing of the door, which is measured in advance for the cooling storage of the model, can be adopted. This compensation time may vary depending on the environmental temperature and the cooling set temperature (i.e., the cooling temperature range). Therefore, for example, the compensation time may be stored in the memory unit M or the memory unit JM as a table or the like for values for each environmental temperature and cooling set temperature (i.e., cooling temperature range), and the value stored in the memory unit M or the memory unit JM may be used. The number of times the door 13 is opened and closed may be detected by the door opening and closing sensor 34. This makes the first appropriate range more appropriate, and improves the accuracy of determining that a malfunction has occurred in the cooling unit 20.

[Condition (e)]
Whether the door 13 has been opened or closed can be known by whether the door opening/closing sensor 34 detects the opening or closing of the door 13. When the door 13 is opened or closed, the temperature in the storage chamber 14 fluctuates greatly, which can have a significant effect on the operation rate of the compressor 21. Therefore, it is preferable not to use data indicating the operation status of the cooling storage 10 acquired during the cooling operation when the door 13 is opened or closed for determining the appropriate range of the temperature difference between the center 22B and the outlet 22C of the condenser 22 and the appropriate range of the operation rate of the compressor. This can increase the accuracy of the appropriate range of the temperature difference and the appropriate range of the operation rate of the compressor.

When any of the above conditions (b), (c), or (e) is adopted, the first appropriate range determination unit 82 can determine the first appropriate range as soon as information that satisfies the respective adoption condition is collected during cooling operation.

The first to fourth optimum range determination units 82 to 85 are configured not to use data indicating the operating status of the cooling storage unit 10 acquired during the cooling operation when any one, two, three, four, or five of the above conditions (a) to (e) are satisfied, in order to determine the optimum range of the temperature difference between the center 22B and the outlet 22C of the condenser 22 and the optimum range of the compressor operation rate. This makes it possible to more accurately determine whether the compressor's operating condition has increased, in other words, whether the cooling performance of the cooling unit 20 has decreased.

<Embodiment 3>
The compressor 21 in the cooling storage 10 in the above-mentioned first and second embodiments is a constant speed controlled compressor. In contrast, the compressor 121 in the cooling storage 110 in the third embodiment is an inverter controlled compressor that is inverter controlled to change the rotation speed of the drive motor. The rotation speed of the compressor 121 is used as information regarding the drive state of the compressor 121 instead of the operation rate of the compressor. Also, instead of the first optimum range which is the optimum range of the operation rate of the compressor, an optimum range of the rotation speed of the compressor 121 can be used. The other configurations may be the same as those in the first embodiment, and a description of the same configurations, actions, and effects will be omitted.

In the compressor 121 of the third embodiment, the rotation speed of the electric motor (not shown) as the driving source is variable. In addition, an upper limit is set for the rotation speed of the electric motor in this type of compressor 121. For example, the ambient temperature or the temperature inside the cabinet is acquired by the sensors 16T and 26, and when the operating margin of the compressor 121 is low due to the high ambient temperature or the temperature inside the cabinet, the upper limit of the rotation speed of the electric motor is controlled to be low. This makes it possible to fully utilize the cooling capacity while suppressing excessive current flow to the electric motor, etc. In addition, in this type of cooling unit 120, for example, when the ambient temperature is low, the input current is lower than when the ambient temperature is high, even if the rotation speed of the electric motor is the same. Therefore, the cooling storage 110 may acquire the ambient temperature or the temperature inside the cabinet by the sensors 16T and 26, and when the operating margin of the compressor 121 is high due to the low ambient temperature or the temperature inside the cabinet, the upper limit of the rotation speed of the electric motor may be controlled to be higher. This allows the cooling capacity to be maximized. To control the compressor 121 in this example, the method disclosed in Japanese Patent Application Laid-Open No. 2006-207893 can be used, for example.

Graphs showing the relationship between the operating time, the rotation speed of the compressor 21, the temperature of the storage chamber 14, the operation rate of the compressor 21, and the average rotation speed of the compressor 21 for such a cooling unit 120 are shown in FIG. 12 from top to bottom. During the cold storage period in the cooling operation of the cooling storage 110, the compressor 121 is usually operated intermittently at a relatively low rotation speed, as shown in the time t0 to t1. However, if any malfunction occurs in the cooling unit 120, the cooling performance of the cooling unit 120 will decrease, so as shown in the time t1 to t2, the electric motor controls the rotation speed of the compressor 121 to be relatively increased, for example, in response to changes in the temperature inside the storage. In the inverter-controlled compressor 121, the rotation speed is increased as the cooling performance of the cooling unit 120 decreases (i.e., as the time progresses from t1 to t2). Here, even if the rotation speed of the compressor 121 is changed, the operation rate of the compressor 121 remains constant because the period in the intermittent operation from time t0 to t2 is constant.

If the compressor 121 rotation speed reaches the upper limit at time t2 but the cooling performance continues to deteriorate, the electric motor operates the compressor 121 continuously with the rotation speed at the upper limit. Then, while the compressor operation rate during intermittent operation from time t0 to t2 was constant according to the cycle, the compressor operation rate becomes 100% during continuous operation after time t2. If the cooling performance of the cooling unit 120 further deteriorates, for example, after time t3, it is no longer possible to maintain the temperature of the storage chamber 14 close to the cooling set temperature. When the compressor 121 is inverter controlled, the degree of deterioration of the cooling performance of the cooling unit 120 cannot be grasped by the operation rate of the compressor 121, but can be grasped, for example, by the rotation speed of the compressor 121.

Therefore, in the third embodiment, information on the rotation speed of the compressor 121 can be used as information on the drive state of the compressor 121 during cooling operation. The rotation speed of the compressor 121 may be set in multiple stages (for example, nine stages from 0 speed to 8 speed) depending on the compressor 121 used, or may be set to an arbitrary rotation speed that is continuously (continuously) changed. The cooling storage 110 is configured to transmit information on the rotation speed of the compressor 121 during cooling operation to the information processing device 180 as information on the drive state of the compressor 121.

[Determination of the first appropriate range]
In the information processing device 180, the acquisition unit 181 acquires information on the rotation speed of the compressor 121 during cooling operation sent from the cooling storage 110, and based on this information on the rotation speed, the first appropriate range determination unit 182 determines an appropriate range of the rotation speed of the compressor 121. As in the first and second embodiments, the first appropriate range determination unit 182 determines a first appropriate range within which the rotation speed of the compressor 121 can be considered appropriate based on the reference rotation speed.

Here, in the compressor 121 that is inverter controlled, the rotation speed of the compressor 121 changes in various ways during one cooling operation. Therefore, the first appropriate range determination unit 182 may determine the average rotation speed per unit time of the compressor 121 during one cooling operation as the appropriate rotation speed, and determine the appropriate range of the average rotation speed based on this appropriate rotation speed. At the bottom of FIG. 12, a graph of the average rotation speed per unit time of the compressor 121 during one cooling operation is shown. The average rotation speed of the compressor can be calculated, for example, based on the following formula: average rotation speed (Hz) = [rotation speed (0 Hz) x operating time at rotation speed 0 Hz + rotation speed (X Hz) x operating time at rotation speed X Hz + ... + rotation speed (upper limit value Hz) x operating time at upper limit value of rotation speed] ÷ (1 cycle time); Note that X in the formula indicates each rotation speed set in the compressor 121 (excluding 0 Hz and the upper limit value).

In this embodiment 3, the compressor 121 is an inverter-controlled compressor that is subjected to inverter control that changes the rotation speed of the drive motor. In addition, the rotation speed of the compressor 121 (more specifically, the average rotation speed) is used as information regarding the drive state of the compressor 121.

[Condition (b)]
When the compressor 121 is an inverter-controlled compressor, the condition (b) adopted by the first optimum range determination unit 182 when deciding the optimum range of the average rotation speed of the compressor can be interpreted as follows. That is, when the period during which the temperature inside the cabinet is controlled from one upper limit cooling temperature (or lower limit cooling temperature) to the next upper limit cooling temperature (or lower limit cooling temperature) in the cooling operation is defined as one cycle, when the fluctuation in the rotation speed of consecutive multiple cycles (e.g., three cycles) is small (for example, within ±3 Hz of the average value, as an example, when the rotation speed of the compressor is in the range of the average rotation speed ±3 Hz), the average rotation speed of the multiple cycles may be adopted as the average rotation speed for one cooling operation. When there are multiple cycles in which the fluctuation in the compressor rotation speed is small, the average rotation speed of any of the consecutive multiple cycles can be adopted as the average rotation speed for the cooling operation.

With this configuration, even if the compressor 21 is an inverter-controlled compressor, it is possible to determine whether the cooling performance of the cooling storage unit 110 has decreased, and if the cooling performance has decreased, it is possible to appropriately determine what the cause of the decrease is. As a result, a malfunction of the cooling storage unit 10 caused by a refrigerant leak can be detected without using special equipment such as a gas detector.

<Other embodiments>
The present technology is not limited to the examples disclosed in the above embodiments, and the following aspects are also included in the scope of the present technology. In addition, the present technology can be implemented in various modified aspects without departing from the essence of the technology.

(1) In the first embodiment, when the results of steps S41 and S42 in FIG. 8 are YES, it is determined that the air filter 32 is clogged. However, the determination of whether the air filter 32 is clogged may be based on other criteria. For example, the operation rate or rotation speed of the compressor in multiple (e.g., two) consecutive cooling operations via the defrosting operation may be compared with a reference operation rate, and the air filter 32 may be determined to be clogged if the operation rate or rotation speed in the first and second operations is significantly higher than the reference operation rate (for example, 10% or 10 Hz or higher). In this way, when the operation rate or rotation speed of the compressor is significantly higher for a certain period of time during the cooling operation, it is determined that the air filter is clogged, thereby reducing the possibility of erroneous detection due to other external factors such as changes in the environmental temperature.

(2) In the first embodiment, the air filter 32 was determined to be clogged when the answer was YES in step S42 in FIG. 8. In other words, the air filter 32 was determined to be clogged when the second temperature difference exceeded the second appropriate range. However, the determination of whether the air filter 32 was clogged may be made based on other criteria. For example, the air filter 32 may be determined to be clogged when the second temperature difference, which is the temperature difference between the ambient temperature and the temperature of the central portion 22B of the condenser 22, is 1 K or more larger than the reference temperature difference for a certain period of time (e.g., three days). In this way, by determining that the air filter is clogged when the second temperature difference is significantly high for a certain period of time during cooling operation, the possibility of erroneous detection due to other external factors such as changes in ambient temperature can be reduced.

(3) In the above embodiment, the control device 50 of the cooling storage 10 is provided with an I/F, a receiving unit 55, and a transmitting unit 56, and information is transmitted and received between the cooling storage 10 and the information processing device 80 using the functions of the I/F, the receiving unit 55, and the transmitting unit 56. However, the cooling storage 10 may additionally include, for example, a data communication device, and may be configured to transmit and receive information between the cooling storage 10 and the information processing device 80 via the data communication device. The data communication device may include, for example, a wireless master unit and a wireless slave unit. In addition, the wireless master unit and the wireless slave unit are configured to be capable of wireless communication for data transmission between each other, the wireless slave unit is configured to be capable of wired communication with the control device 50, and the wireless master unit is configured to be capable of wireless communication with the information processing device 80. According to this configuration, by providing a data communication system for the cooling storage 10 that does not have a communication function with an external device, an abnormality can be detected by the abnormality detection system according to the present technology. The data communication system may be capable of wireless communication such as specific low-power radio, simple radio, or in-house radio, and examples of such systems include data communication systems that use radio waves of frequencies specified as standard specifications by the IEEE (Institute of Electrical and Electronics Engineers) or radio waves specified in Article 6, Paragraph 1, Paragraph 3, and Paragraph 4, Items 1 to 4 (especially Items 2 and 4) of the Regulations for Enforcement of the Radio Law (one example is a device compatible with Wi-SUN (Wireless Smart Utility Network, IEEE802.15.4g)).

(4) In the above embodiment, the owner of the other computer 60 is not particularly limited, and may be a user of the cooling storage facility 10, a serviceman who performs maintenance on the cooling storage facility 10, or an administrator who manages the anomaly detection system 1.

(5) In the above embodiment, the method of reporting an abnormality is not particularly limited. For example, an error message indicating an abnormality in each part of the cooling storage cabinet 10 may be displayed on the display unit of the cooling storage cabinet 10, or if the cooling storage cabinet 10 is equipped with a light-emitting means or a sound-producing means, an error message indicating the abnormality may be output using light, sound, or the like. In addition, an email or message reporting the abnormality may be sent from the information processing device 80 to the other computer 60, or a message may be sent by telephone to a user, serviceman, administrator, etc.

(6) In the above embodiment, the information processing device 80 is a management server that manages information related to the cooling storage 10, and may be configured to provide software for analyzing management information (typically, SaaS: Software as a Service) to other computers 60 via the Internet through an API (Application Programming Interface) for linking with external systems. In this case, the notification of an abnormality may be configured to be executed by the software for analyzing management information. In addition, the software for analyzing management information may be configured to display a message prompting the user to check a graph showing the change in temperature inside the storage over time when a signal indicating an abnormality in the sealing member is received from the information processing device 80. In addition, the software for analyzing management information may be configured to periodically notify the user of an abnormality when a signal indicating an abnormality in the cooling storage 10 is frequently received from the information processing device 80 (for example, twice or more in two weeks) until maintenance of the relevant part of the cooling storage is performed, since there is a high possibility that a malfunction has occurred in any part of the cooling storage.

(7) In the above embodiment, the cooling operation and defrosting operation of the cooling storage facility 10 are merely examples, and may be modified or various other operating methods may be adopted as long as the essence of the present technology is not compromised.

(8) In the above-mentioned anomaly detection system 1, only one cooling storage unit 10 is communicatively connected to one information processing device 80. However, multiple cooling storage units 10 may be communicatively connected to one information processing device 80. Also, in the above-mentioned anomaly detection system 1, information regarding an anomaly for one cooling storage unit 10 is output to one other computer 60. However, the system may be configured so that information regarding anomalies for multiple cooling storage units 10 is output to one other computer 60.

(9) The information processing device 80 was a computer equipped with a CPU as a processor. However, the information processing device 80 may include an MPU (Micro Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application-Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), etc. as a processor, and may execute each process using a logic circuit (hardware) or a dedicated circuit formed in an integrated circuit (IC) chip, an LSI (Large Scale Integration), etc.

(10) In addition, in this technology, the computer program may be provided in a form recorded on any non-transitory computer readable medium (N-CRM).

(11) In the above embodiment, the configuration of each part of the cooling storage can be modified within the scope that does not impair the essence of the technology of the present application. As an example, an example in which a capillary tube is used as the pressure reducing mechanism in the cooling unit has been disclosed, but the pressure reducing mechanism may be, for example, a known expansion valve. In addition, in the above embodiment, an example in which an NTC thermistor is used as the temperature sensor has been disclosed, but the temperature sensor may be, for example, other thermistors such as a PTC thermistor or a CTR thermistor, a thermocouple, an IC temperature sensor, a metal (e.g., platinum) resistance temperature detector, a linear resistor, an infrared temperature sensor, etc.

1...Abnormality detection system, 10, 110...Cooling storage, 11...Storage body, 14...Storage room, 20, 120...Cooling unit, 21, 121...Compressor, 22...Condenser, 23...Expansion valve, 24...Evaporator, 25...Refrigerant pipe, 27...Defrosting heater, 30...Evaporator fan, 32...Air filter, 34...Door opening/closing sensor, 35...Sealing member, 50...Control device, 60...Other computers data, 80, 180...information processing device, 81, 181...acquisition unit, 82, 182...first appropriate range determination unit, 83, 183...second range determination unit, 84, 184...third range determination unit, 85, 185...fourth range determination unit, 86, 186...judgment unit, 87, 187...output unit, 24T...first temperature sensor, 26...second temperature sensor, 22T...third temperature sensor, 16T...fourth temperature sensor

Claims (10)

A storage body having a storage chamber;
a cooling unit including a compressor, a condenser, an expansion valve, an evaporator, a refrigerant pipe for circulating a refrigerant therethrough, and a heater for heating the evaporator;
A first temperature sensor capable of detecting a temperature of the evaporator at an inlet of the evaporator;
A second temperature sensor capable of detecting the temperature of the air in the storage chamber;
Equipped with
An information processing device that detects an abnormality in a cooling storage facility having a configuration that executes a cooling operation in which air in the storage room is taken in the cooling unit, cooled, and then returned to the storage room,
an acquisition unit that acquires information related to a driving state of the compressor and information detected by the first temperature sensor and the second temperature sensor;
a determination unit that determines that a refrigerant leak has occurred when a first temperature difference, which is a temperature difference between the temperature of the air in the storage chamber and the temperature at the inlet of the evaporator when the driving state of the compressor is increasing, falls outside a first temperature difference appropriate range, which is an appropriate range of the temperature difference between the temperature of the air in the storage chamber and the temperature at the inlet of the evaporator, which is predetermined based on information acquired by the acquisition unit when there is no refrigerant leakage from the refrigerant pipe;
an output unit that outputs information indicating an abnormality when the determination unit determines that a refrigerant leak has occurred;
Equipped with
The cooling storage facility includes:
A configuration in which, when a predetermined defrosting condition is satisfied, a defrosting operation is performed in which the evaporator is heated by the heater to melt frost adhering to the evaporator;
A timer that detects the time required for the defrosting operation,
The acquisition unit acquires information regarding a time required for the defrosting operation detected by the timer,
The determination unit is
before determining whether the first temperature difference is outside the first temperature difference appropriate range, determining whether a time required for the defrosting operation most recently performed is within a defrosting time appropriate range, which is an appropriate range of the time required for the defrosting operation that is predetermined based on information acquired by the acquisition unit when there is no refrigerant leakage from the refrigerant pipe,
When the defrosting time is within the proper range, it is determined whether the first temperature difference is out of the first temperature difference proper range,
When the defrosting time falls outside the appropriate range, the information processing device determines that an abnormality other than a refrigerant leak has occurred . the condenser includes an inlet through which the refrigerant compressed by the compressor is delivered, an outlet through which the refrigerant is delivered toward the expansion valve, and a central portion between the inlet and the outlet,
The cooling storage facility includes:
a third temperature sensor capable of detecting a temperature of the condenser at the central portion of the condenser;
A fourth temperature sensor capable of detecting the temperature of an environment in which the cooling storage is installed;
Further equipped with
The acquisition unit acquires information detected by the third temperature sensor and the fourth temperature sensor,
The determination unit is
before determining whether or not a time required for the most recently executed defrosting operation is within the appropriate defrosting time range, determining whether or not a second temperature difference, which is a temperature difference between the environmental temperature and the temperature of the central part of the condenser when the driving state of the compressor is increasing, is within a second appropriate temperature difference range, which is an appropriate range of the temperature difference between the environmental temperature and the temperature of the central part of the condenser, that is determined in advance based on information acquired by the acquisition unit when there is no refrigerant leakage from the refrigerant pipe;
When the temperature difference is within the second appropriate range, it is determined whether or not the time required for the most recently performed defrosting operation is within the appropriate defrosting time range.
The information processing apparatus according to claim 1 , wherein when the temperature difference is outside the second appropriate range, it is determined that an abnormality other than a refrigerant leak has occurred . 3 . The information processing device according to claim 1 , further comprising an appropriate range determination unit that determines the first temperature difference appropriate range based on information regarding the first temperature difference when there is no refrigerant leakage from the refrigerant pipe, the information being acquired by the acquisition unit. The compressor is subjected to constant speed control in which the rotation speed of a drive motor is kept constant and driving and stopping are switched on and off.
The information processing device according to claim 1 , wherein the information relating to the drive state of the compressor is an operation rate of the compressor. The compressor is inverter-controlled to change the rotation speed of a drive motor.
The information processing device according to claim 1 , wherein the information relating to the drive state of the compressor is a rotation speed of the compressor. A storage body having a storage chamber;
a cooling unit including a compressor, a condenser, an expansion valve, an evaporator, a refrigerant pipe for circulating a refrigerant therethrough, and a heater for heating the evaporator;
Equipped with
A first temperature sensor capable of detecting a temperature of the evaporator at an inlet of the evaporator;
A second temperature sensor capable of detecting the temperature of the air in the storage chamber;
Further equipped with
An abnormality detection method for detecting an abnormality in a cooling storage facility having a configuration for performing a cooling operation in which air in the storage room is taken in the cooling unit, cooled, and then returned to the storage room, comprising:
an acquiring step of acquiring information related to a driving state of the compressor and information detected by the first temperature sensor and the second temperature sensor;
a determination step of determining that a refrigerant leak has occurred when a first temperature difference, which is a temperature difference between the temperature of the air in the storage chamber and the temperature at the inlet of the evaporator when the driving state of the compressor is increasing, falls outside a first temperature difference appropriate range, which is an appropriate range of the temperature difference between the temperature of the air in the storage chamber and the temperature at the inlet of the evaporator, which is predetermined based on information acquired by the acquisition step when there is no refrigerant leakage from the refrigerant pipe ;
an output step of outputting information indicating an abnormality when it is determined that a refrigerant leak has occurred in the determination step ;
Including ,
The cooling storage facility includes:
A configuration in which, when a predetermined defrosting condition is satisfied, a defrosting operation is performed in which the evaporator is heated by the heater to melt frost adhering to the evaporator;
A timer that detects the time required for the defrosting operation,
The acquisition step acquires information regarding a time required for the defrosting operation detected by the timer,
The determining step includes:
Before determining whether or not the first temperature difference is outside the first temperature difference appropriate range, it is determined whether or not a time required for the defrosting operation most recently performed is within a defrosting time appropriate range, which is an appropriate range of a time required for the defrosting operation that is predetermined based on the information acquired in the acquiring step when there is no refrigerant leakage from the refrigerant pipe;
When the defrosting time is within the proper range, it is determined whether the first temperature difference is out of the first temperature difference proper range,
The abnormality detection method determines that an abnormality other than a refrigerant leak has occurred when the defrosting time falls outside the appropriate range . A storage body having a storage chamber;
a cooling unit including a compressor, a condenser, an expansion valve, an evaporator, a refrigerant pipe for circulating a refrigerant therethrough, and a heater for heating the evaporator;
Equipped with
A first temperature sensor capable of detecting a temperature of the evaporator at an inlet of the evaporator;
A second temperature sensor capable of detecting the temperature of the air in the storage chamber;
Further equipped with
A program for causing a computer to execute detection of an abnormality in a cooling storage facility having a configuration for executing a cooling operation in which air in the storage room is taken in the cooling unit, cooled, and then returned to the storage room,
an acquiring step of acquiring information related to a driving state of the compressor and information detected by the first temperature sensor and the second temperature sensor;
a determination step of determining that a refrigerant leak has occurred when a first temperature difference, which is a temperature difference between the temperature of the air in the storage chamber and the temperature at the inlet of the evaporator when the driving state of the compressor is increasing, falls outside a first temperature difference appropriate range, which is an appropriate range of the temperature difference between the temperature of the air in the storage chamber and the temperature at the inlet of the evaporator, which is predetermined based on information acquired by the acquisition step when there is no refrigerant leakage from the refrigerant pipe ;
an output step of outputting information indicating an abnormality when it is determined that a refrigerant leak has occurred in the determination step ;
on the computer,
The cooling storage facility includes:
A configuration in which, when a predetermined defrosting condition is satisfied, a defrosting operation is performed in which the evaporator is heated by the heater to melt frost adhering to the evaporator;
A timer that detects the time required for the defrosting operation,
The acquisition step acquires information regarding a time required for the defrosting operation detected by the timer,
The determining step includes:
Before determining whether or not the first temperature difference is outside the first temperature difference appropriate range, it is determined whether or not a time required for the defrosting operation most recently performed is within a defrosting time appropriate range, which is an appropriate range of a time required for the defrosting operation that is predetermined based on the information acquired in the acquiring step when there is no refrigerant leakage from the refrigerant pipe;
When the defrosting time is within the proper range, it is determined whether the first temperature difference is out of the first temperature difference proper range,
The program determines that an abnormality other than a refrigerant leak has occurred when the defrosting time falls outside the appropriate range . A storage body having a storage chamber;
a cooling unit including a compressor, a condenser, an expansion valve, an evaporator, a refrigerant pipe for circulating a refrigerant therethrough, and a heater for heating the evaporator;
A first temperature sensor capable of detecting a temperature of the evaporator at an inlet of the evaporator;
A second temperature sensor capable of detecting the temperature of the air in the storage chamber;
Equipped with
a means for executing a cooling operation in which air in the storage chamber is taken into the cooling unit, cooled, and then returned to the storage chamber;
a means for transmitting information regarding the operating state of the compressor and information acquired by the first temperature sensor and the second temperature sensor to the information processing device according to any one of claims 1 to 5 , said information processing device being communicatively connected;
a means for receiving information indicating the abnormality from the information processing device when the information processing device determines that a refrigerant leak has occurred;
a means for notifying the abnormality based on the received information;
The cooling storage facility further comprises: The cooling storage facility according to claim 8 , further comprising the information processing device according to any one of claims 1 to 5 . An anomaly detection system including a cooling storage unit, a sensor, and an information processing device,
The cooling storage facility includes:
A storage body having a storage chamber;
a cooling unit including a compressor, a condenser, an expansion valve, an evaporator, a refrigerant pipe for circulating a refrigerant therethrough, and a heater for heating the evaporator;
A first temperature sensor capable of detecting a temperature of the evaporator at an inlet of the evaporator;
A second temperature sensor capable of detecting the temperature of the air in the storage chamber;
In addition to providing
a means for executing a cooling operation in which air in the storage chamber is taken into the cooling unit, cooled, and then returned to the storage chamber;
a means for transmitting information regarding a drive state of the compressor and information acquired by the first temperature sensor and the second temperature sensor to the information processing device connected in a communicable manner;
a means for receiving information indicating the abnormality from the information processing device when the information processing device determines that a refrigerant leak has occurred;
a means for notifying the abnormality based on the received information;
Further equipped with
The information processing device includes:
an acquisition unit that acquires information related to a driving state of the compressor and information detected by the first temperature sensor and the second temperature sensor;
a determination unit that determines that a refrigerant leak has occurred when a first temperature difference, which is a temperature difference between the temperature of the air in the storage chamber and the temperature at the inlet of the evaporator when the driving state of the compressor is increasing, falls outside a first temperature difference appropriate range, which is an appropriate range of the temperature difference between the temperature of the air in the storage chamber and the temperature at the inlet of the evaporator, which is predetermined based on information acquired by the acquisition unit when there is no refrigerant leakage from the refrigerant pipe;
an output unit that outputs information indicating an abnormality when the determination unit determines that a refrigerant leak has occurred;
Equipped with
The cooling storage facility includes:
A configuration in which, when a predetermined defrosting condition is satisfied, a defrosting operation is performed in which the evaporator is heated by the heater to melt frost adhering to the evaporator;
A timer that detects a time required for the defrosting operation,
The acquisition unit acquires information regarding a time required for the defrosting operation detected by the timer,
The determination unit is
before determining whether the first temperature difference is outside the first temperature difference appropriate range, determining whether a time required for the defrosting operation most recently performed is within a defrosting time appropriate range, which is an appropriate range of the time required for the defrosting operation that is predetermined based on information acquired by the acquisition unit when there is no refrigerant leakage from the refrigerant pipe,
When the defrosting time is within the appropriate range, it is determined whether the first temperature difference is out of the first appropriate temperature difference range,
An abnormality detection system that determines that an abnormality other than a refrigerant leak has occurred if the defrosting time falls outside the appropriate range .

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