CN112752938A

CN112752938A - Refrigerant leakage determination device, refrigeration device provided with same, and refrigerant leakage determination method

Info

Publication number: CN112752938A
Application number: CN201980062442.XA
Authority: CN
Inventors: 佐藤喜一郎; 仲野政贤
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2018-09-28
Filing date: 2019-09-26
Publication date: 2021-05-04
Anticipated expiration: 2039-09-26
Also published as: US20220034568A1; JP2020056509A; JP6887979B2; EP3859249B1; CN112752938B; EP3859249A4; EP3859249A1; DK3859249T3; WO2020067296A1

Abstract

The refrigerant leakage determination device (60) includes a calculation unit (66) and a determination unit (67). A calculation unit (66) calculates the degree of deviation from the normal state of the refrigerant circuit (20) based on data related to the operation of the refrigeration apparatus (1). A determination unit (67) determines whether or not there is a refrigerant leak based on the calculation result of the calculation unit (66), or predicts the occurrence time of the refrigerant leak. A calculation unit (66) calculates a first index value and a second index value, the first index value being based on data related to the operation of the refrigeration device (1) in the first period among the data related to the operation of the refrigeration device (1) The second index value is calculated based on data related to the operation of the refrigerating apparatus (1) in the second period having a length different from that of the first period, and the refrigerant circuit (1) is calculated based on the first index value and the second index value. 20) The degree of deviation from the normal state. The determination unit (67) is configured to determine whether or not there is a refrigerant leak based on the degree of deviation of the refrigerant circuit (20) from the normal state, or to predict when the refrigerant leak occurs.

Description

Refrigerant leakage determination device, refrigeration device provided with same, and refrigerant leakage determination method

Technical Field

The present disclosure relates to a refrigerant leakage determination device, a refrigeration device including the refrigerant leakage determination device, and a refrigerant leakage determination method.

Background

Conventionally, in an air conditioner in which an outdoor unit having a compressor and an indoor unit are connected by a refrigerant pipe to constitute a refrigeration cycle, a structure for determining whether or not there is refrigerant leakage is known (for example, see patent document 1). In such an air conditioner, whether or not there is a refrigerant leak is determined by comparing the outside air temperature at the time of starting the compressor in the initial stage after the air conditioner is installed, the discharge side temperature of the compressor when the air conditioner is operated under a predetermined condition, the outside air condition at the time of starting the compressor thereafter, and the discharge side temperature of the compressor when the air conditioner is operated under the same predetermined condition.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2013-204871

Disclosure of Invention

Technical problem to be solved by the invention

In the conventional air conditioner, in order to determine whether there is a refrigerant leak, it is necessary to set the operation conditions of the air conditioner at the initial stage after the air conditioner and the operation conditions of the subsequent air conditioner at the same time, and in order to determine whether there is a refrigerant leak, it is necessary to perform a special operation. Therefore, the air conditioner cannot perform the normal operation while determining whether there is the refrigerant leakage. The above-described problem is not limited to the air conditioner, but occurs similarly in a refrigeration apparatus including a refrigerant circuit.

An object of the present disclosure is to provide a refrigerant leakage determination device that does not require a special operation of a refrigeration device in order to determine whether there is refrigerant leakage, a refrigeration device including the refrigerant leakage determination device, and a refrigerant leakage determination method.

Technical scheme for solving technical problem

The refrigerant leakage determination device of the present disclosure determines refrigerant leakage in the refrigeration apparatus 1. The refrigeration apparatus 1 includes a refrigerant circuit 20, and the refrigerant circuit 20 includes a compressor, a condenser, a pressure reducing device, and an evaporator, and a refrigerant is circulated through the compressor, the condenser, the pressure reducing device, and the evaporator. The refrigerant leakage determination device includes a calculation unit and a determination unit. The calculation unit calculates a degree of deviation of the refrigerant circuit from a normal state (Japanese style better) from data relating to operation of the refrigeration apparatus. The determination unit determines whether there is refrigerant leakage or predicts the timing of refrigerant leakage occurrence based on the calculation result of the calculation unit. The calculation unit is configured to: the method includes calculating a first index value calculated from data relating to the operation of the refrigeration apparatus in a first period of time among data relating to the operation of the refrigeration apparatus, and calculating a second index value calculated from data relating to the operation of the refrigeration apparatus in a second period of time having a length different from that of the first period of time, and calculating a degree of deviation of the refrigerant circuit from a normal state based on the first index value and the second index value. The determination unit is configured to determine whether or not the refrigerant leaks, or to predict the refrigerant leak occurrence timing, based on a degree of deviation of the refrigerant circuit from a normal state.

According to the above configuration, the degree of deviation of the refrigerant circuit from the normal state can be calculated from the degree of deviation of the first index value and the second index value calculated using data relating to the operation of the refrigeration apparatus including the normal operation of the refrigeration apparatus and the operation of the pre-use inspection of the refrigeration apparatus. This makes it possible to determine whether or not there is a refrigerant leak or to predict the timing of occurrence of the refrigerant leak. The data relating to the operation of the refrigeration apparatus can be obtained, for example, by an operation including a normal operation of the refrigeration apparatus and an operation of a pre-use inspection of the refrigeration apparatus. Therefore, it is possible to determine whether or not there is a refrigerant leak or predict the timing of occurrence of the refrigerant leak without performing a special operation for determining the refrigerant leak.

The refrigerant leakage determination method of the present disclosure determines refrigerant leakage in the refrigeration apparatus 1. The refrigeration device 1 comprises a refrigerant circuit 20. The refrigerant circuit 20 includes a compressor, a condenser, a pressure reducing device, and an evaporator, and a refrigerant circulates through the compressor, the condenser, the pressure reducing device, and the evaporator. The refrigerant leakage determination method includes storing data relating to operation of the refrigeration apparatus. The refrigerant leakage determination method further includes the steps of: a first index value is calculated from data relating to the operation of the refrigeration apparatus in a first period, and a second index value is calculated from data relating to the operation of the refrigeration apparatus in a second period having a length different from that of the first period. The refrigerant leakage determination method further includes the steps of: and calculating the degree of deviation of the refrigerant circuit from the normal state based on the first index value and the second index value. The refrigerant leakage determination method further includes the steps of: the method includes determining whether or not there is a refrigerant leak, or predicting a timing of occurrence of the refrigerant leak, based on a degree of deviation of the refrigerant circuit from a normal state.

Drawings

Fig. 1 is a schematic diagram illustrating a refrigeration apparatus according to the present embodiment.

Fig. 2 is a block diagram showing an electrical configuration of the refrigerating apparatus.

Fig. 3 is a block diagram showing an electrical configuration of a refrigerant leakage determination device of the refrigeration apparatus.

Fig. 4 (a) is a graph showing an example of the progression of the discharge-side refrigerant temperature ratio of the refrigeration apparatus, and (b) is a graph showing an example of the progression of the degree of deviation of the first index value from the second index value.

Fig. 5 is a flowchart showing an example of the processing procedure of the refrigerant leakage determination process executed by the refrigerant leakage determination device.

Fig. 6 is a schematic diagram of a refrigeration apparatus according to a modification.

Detailed Description

Next, a transport refrigeration apparatus (hereinafter, simply referred to as "refrigeration apparatus 1"), which is an example of a refrigeration apparatus, will be described with reference to the drawings. The refrigeration system 1 is a system for cooling the inside of a container such as an offshore container or a container for a land transportation trailer, for example. The interior of the casing of the refrigeration apparatus 1 is separated into an in-box storage space in which air in the box circulates and an out-box storage space in which air outside the box circulates.

As shown in fig. 1, the refrigeration apparatus 1 includes a refrigerant circuit 20, and the refrigerant circuit 20 connects a compressor 11, a condenser 12, an evaporator 13, and the like together via refrigerant pipes. The refrigerant circuit 20 includes a main circuit 21, a hot gas bypass circuit 22, and a liquid refrigerant bypass circuit 31.

In the main circuit 21, a motor-driven compressor 11, a condenser 12, a first expansion valve 14A, which is an example of a pressure reducing device, and an evaporator 13 are connected in series in this order by refrigerant pipes.

As shown in fig. 1, the compressor 11, the condenser 12, the first expansion valve 14A, the outside air blower 15 for circulating the outside air through the condenser 12, and the like are housed in the outside housing space. Further, the evaporator 13, an in-box blower 16 for circulating the in-box air in the evaporator 13, and the like are housed in the in-box housing space.

The compressor 11 may be, for example, a rotary compressor or a scroll compressor. The operating frequency of the compressor 11 is controlled by an inverter, and the rotational speed thereof is controlled, whereby the operating capacity thereof is configured to be variable.

The condenser 12 and the evaporator 13 may employ a fin-and-tube heat exchanger. The condenser 12 exchanges heat between the outside air supplied by the outside air blower 15 and the refrigerant circulating in the condenser 12. The evaporator 13 exchanges heat between the in-tank air supplied by the in-tank blower 16 and the refrigerant circulating in the evaporator 13. An example of the outside-box blower 15 and the inside-box blower 16 is a propeller fan. A water collection tray 28 is provided below the evaporator 13. The water collection tray 28 collects frost and ice cubes peeled off from the evaporator 13, dew condensed in the air, and the like.

The first expansion valve 14A may be, for example, an electric expansion valve whose opening degree is variable by a pulse motor.

A first opening/closing valve 17A and a shutoff valve 18 are provided in this order in the refrigerant flow direction in a high-pressure gas pipe 23 connecting the compressor 11 and the condenser 12. The first opening/closing valve 17A may be, for example, an electric expansion valve whose opening degree is variable by a pulse motor. The shutoff valve 18 allows refrigerant to flow in the direction of the arrow shown in fig. 1.

At the high-pressure liquid pipe 24 connecting the condenser 12 and the first expansion valve 14A, an accumulator 29, a second opening/closing valve 17B, a dryer 30, and a supercooling heat exchanger 27 are provided in this order in the refrigerant flow direction. The second opening/closing valve 17B may be, for example, an electromagnetic valve that can be opened and closed freely.

The supercooling heat exchanger 27 includes a primary passage 27a and a secondary passage 27b configured to exchange heat with each other. The primary-side passage 27a is provided between the dryer 30 and the first expansion valve 14A in the main circuit 21. The secondary passage 27b is provided in the liquid refrigerant bypass circuit 31. The liquid refrigerant bypass circuit 31 is a bypass circuit connecting the high-pressure liquid pipe 24 and an intermediate pressure portion (not shown) of the compression mechanism portion in the compressor 11. The third opening/closing valve 17C and the second expansion valve 14B, which is an example of an expansion device, are connected in this order in the flow direction of the high-pressure liquid refrigerant between the high-pressure liquid pipe 24 and the secondary-side passage 27B in the liquid refrigerant bypass circuit 31. With the above configuration, the liquid refrigerant flowing into the liquid refrigerant bypass circuit 31 from the high-pressure liquid pipe 24 is expanded to an intermediate pressure by the second expansion valve 14B, becomes a refrigerant having a temperature lower than the temperature of the liquid refrigerant flowing through the high-pressure liquid pipe 24, and flows through the secondary passage 27B. Therefore, the high-pressure liquid refrigerant flowing through the primary passage 27a is cooled and subcooled by the refrigerant flowing through the secondary passage 27 b. The third opening/closing valve 17C may be, for example, an electromagnetic valve that can be opened and closed freely. The second expansion valve 14B may be, for example, an electric expansion valve whose opening degree is variable by a pulse motor.

The hot gas bypass circuit 22 connects the high-pressure gas pipe 23 and the inlet side of the evaporator 13, and bypasses the high-pressure high-temperature gas refrigerant discharged from the compressor 11 to the inlet side of the evaporator 13. The hot gas bypass circuit 22 includes a main passage 32, a first branch passage 33 and a second branch passage 34 branched from the main passage 32. The first branch passage 33 and the second branch passage 34 are parallel circuits, one end of each of which is connected to the main passage 32, and the other end of each of which is connected to the inlet side of the evaporator 13, that is, the low-pressure communication pipe 25 between the first expansion valve 14A and the evaporator 13. The fourth opening/closing valve 17D is provided in the main passage 32. The fourth opening/closing valve 17D may be, for example, a freely opening/closing solenoid valve. The first branch passage 33 is constituted by a pipe only. A water collection pan heater 35 is provided in the second branch passage 34. The sump heater 35 is provided at the bottom of the sump 28 to heat the sump 28 with the high-temperature refrigerant.

The refrigeration apparatus 1 is provided with various sensors. In one example, as shown in fig. 1 and 2, the refrigeration apparatus 1 is provided with a discharge temperature sensor 41, a discharge pressure sensor 42, a suction temperature sensor 43, a suction pressure sensor 44, a current sensor 45, a rotation sensor 46, a condensation temperature sensor 47, and an evaporation temperature sensor 48. The sensors 41 to 48 may be known sensors, for example.

The discharge temperature sensor 41 and the discharge pressure sensor 42 are provided, for example, in the vicinity of the discharge port of the compressor 11 in the high-pressure gas pipe 23. The discharge temperature sensor 41 outputs a signal corresponding to the temperature of the discharge gas refrigerant discharged from the compressor 11. The discharge pressure sensor 42 outputs a signal corresponding to the pressure of the discharge gas refrigerant discharged from the compressor 11. The suction temperature sensor 43 and the suction pressure sensor 44 are provided in the vicinity of the suction port of the compressor 11 in the low-pressure gas pipe 26, which is a suction pipe of the compressor 11, for example. The suction temperature sensor 43 outputs a signal corresponding to the temperature of the suction gas refrigerant sucked into the compressor 11. The suction pressure sensor 44 outputs a signal corresponding to the pressure of the suction gas refrigerant sucked into the compressor 11. The current sensor 45 is provided in, for example, an inverter circuit that drives a motor of the compressor 11. The current sensor 45 outputs a signal corresponding to the amount of current flowing in the inverter circuit. The rotation sensor 46 is provided to, for example, a motor of the compressor 11. The rotation sensor 46 outputs a signal corresponding to the rotation speed of the motor.

The condensation temperature sensor 47 is provided in the condenser 12, for example, and outputs a signal corresponding to the condensation temperature of the refrigerant flowing through the condenser 12. In the present embodiment, the condensation temperature sensor 47 is attached to, for example, an intermediate portion of the condenser 12. In this case, the condensation temperature sensor 47 takes the refrigerant temperature in the middle portion of the condenser 12 as the condensation temperature and outputs a signal corresponding to the condensation temperature. In addition, the mounting position of the condensation temperature sensor 47 with respect to the condenser 12 can be arbitrarily changed.

The evaporation temperature sensor 48 is provided in the evaporator 13, for example, and outputs a signal corresponding to the evaporation temperature of the refrigerant flowing through the evaporator 13. In the present embodiment, the evaporation temperature sensor 48 is attached to, for example, an intermediate portion of the evaporator 13. In this case, the evaporation temperature sensor 48 outputs a signal corresponding to the evaporation temperature, taking the refrigerant temperature in the middle portion of the evaporator 13 as the evaporation temperature. In addition, the mounting position of the evaporation temperature sensor 48 with respect to the evaporator 13 can be arbitrarily changed.

As shown in fig. 2, the refrigeration apparatus 1 includes a control device 50 for controlling the operation of the refrigeration apparatus 1 and a notification unit 52. The control device 50 is electrically connected to the discharge temperature sensor 41, the discharge pressure sensor 42, the suction temperature sensor 43, the suction pressure sensor 44, the current sensor 45, the rotation sensor 46, the condensation temperature sensor 47, and the evaporation temperature sensor 48, respectively. The control device 50 is electrically connected to the compressor 11, the first expansion valve 14A, the second expansion valve 14B, the outside-tank fan 15, the inside-tank fan 16, the first opening/closing valve 17A, the second opening/closing valve 17B, the third opening/closing valve 17C, the fourth opening/closing valve 17D, and the notification unit 52. The notification unit 52 notifies the outside of the refrigeration apparatus 1 of information related to the refrigeration apparatus 1. The notification unit 52 has, for example, a display 53 for displaying information related to the refrigeration apparatus 1. In addition, the notification portion 52 may have a speaker instead of the display 53 or in addition to the display 53. In this case, the notification unit 52 may notify information related to the refrigeration apparatus 1 by sound.

The control device 50 includes a control section 51. The control unit 51 includes, for example, an arithmetic device and a storage unit that execute a predetermined control program. The arithmetic device includes, for example, a CPU (central processing unit) or an MPU (micro processing unit). The storage unit stores information used for various control programs and various control processes. The storage unit includes, for example, a nonvolatile memory and a volatile memory. The control unit 51 controls the compressor 11, the

expansion valves

14A, 14B, the outside air blower 15, the inside air blower 16, and the opening/closing valves 17A to 17D based on the detection results of the sensors 41 to 48. The refrigeration apparatus 1 performs a freezing operation, a cooling operation, and a defrosting operation by the control unit 51.

[ freezing and Cooling operation ]

In the freezing and cooling operation, the first opening/closing valve 17A, the second opening/closing valve 17B, and the third opening/closing valve 17C are opened, and the fourth opening/closing valve 17D is closed. The opening degrees of the first expansion valve 14A and the second expansion valve 14B can be appropriately adjusted. Further, the compressor 11, the outside-box blower 15, and the inside-box blower 16 are operated.

During the freezing and cooling operation, the refrigerant circulates as indicated by solid arrows in fig. 1. That is, the high-pressure gas refrigerant compressed by the compressor 11 is condensed by the condenser 12 to become a liquid refrigerant and is stored in the accumulator 29. The liquid refrigerant stored in the accumulator 29 is cooled in the primary-side passage 27a of the supercooling heat exchanger 27 through the second opening/closing valve 17B and the dryer 30 to become a supercooled liquid refrigerant, and flows to the first expansion valve 14A. As shown by the wavy line arrows in fig. 1, a part of the liquid refrigerant flowing out of the accumulator 29 passes through the third opening/closing valve 17C and the second expansion valve 14B as a supercooling source, becomes a refrigerant of an intermediate pressure, flows to the secondary-side passage 27B of the supercooling heat exchanger 27, and cools the liquid refrigerant in the primary-side passage 27 a. The liquid refrigerant supercooled in the supercooling heat exchanger 27 is decompressed by the first expansion valve 14A and flows to the evaporator 13. In the evaporator 13, the low-pressure liquid refrigerant absorbs heat from the air in the tank, and evaporates and gasifies. Thereby, the in-tank air is cooled. The low-pressure gas refrigerant evaporated and gasified in the evaporator 13 is sucked into the compressor 11 and compressed again.

[ defrosting operation ]

When the freezing and cooling operation is continued, frost is deposited on the surface of the heat transfer pipe or the like of the evaporator 13, and the frost gradually grows and thickens. Therefore, the control unit 51 performs the defrosting operation for defrosting the evaporator 13.

The defrosting operation is an operation of defrosting the evaporator 13 by bypassing the high-temperature and high-pressure gas refrigerant compressed in the compressor 11 to the inlet side of the evaporator 13 as indicated by a broken-line arrow in fig. 1. During the defrosting operation, the fourth opening/closing valve 17D is in an open state, and the first opening/closing valve 17A, the second opening/closing valve 17B, the third opening/closing valve 17C, and the second expansion valve 14B are in a fully closed state. Further, the compressor 11 is operated, and the outdoor blower 15 and the indoor blower 16 are stopped.

The high-pressure, high-temperature gas refrigerant compressed by the compressor 11 flows through the main passage 32, and is then branched into the first branch passage 33 and the second branch passage 34 by the fourth opening/closing valve 17D. The refrigerant branched to the second branch passage 34 passes through the sump heater 35. The refrigerant flowing out of the water collection pan heater 35 merges with the refrigerant passing through the first branch passage 33, and flows to the evaporator 13. In the evaporator 13, a high-pressure gas refrigerant (so-called hot gas) flows through the inside of the heat transfer tubes. Therefore, in the evaporator 13, the frost attached to the heat transfer tubes and the fins is gradually heated by the high-temperature gas refrigerant. As a result, the frost adhering to the evaporator 13 is gradually collected to the water collection tray 28. The refrigerant for defrosting of the evaporator 13 is sucked into the compressor 11 and compressed again. Here, ice cubes and the like peeled off from the surface of the evaporator 13 together with water in which frost is melted are collected inside the water collection tray 28. The ice cubes and the like are heated by the refrigerant flowing inside the water collecting tray heater 35 to be melted. The melted water is discharged to the outside of the tank through a predetermined flow path.

As shown in fig. 2, the control device 50 further includes a refrigerant leakage determination device 60, and the refrigerant leakage determination device 60 determines whether or not there is refrigerant leakage, or predicts the timing of occurrence of refrigerant leakage. Here, if refrigerant leakage occurs, the refrigeration apparatus 1 may have an abnormality in which the compression efficiency of the compressor 11 is reduced due to, for example, a shortage of the amount of refrigerant. The refrigerant leakage determination device 60 monitors the temperature of the discharge gas refrigerant discharged from the compressor 11 (hereinafter referred to as "discharge side refrigerant temperature") and determines whether there is refrigerant leakage or not, or predicts the refrigerant leakage occurrence timing.

As shown in fig. 3, the refrigerant leakage determination device 60 includes a data acquisition unit 61, a data storage unit 62, a preprocessing unit 63, a refrigerant leakage determination unit 64, and an output unit 65.

The data acquisition unit 61 is communicably connected to the sensors 41 to 48. The data acquisition unit 61 receives time series data of the sensors 41 to 48. In one example, the sensors 41 to 48 output the detection results at every predetermined time TX to the refrigerant leakage determination device 60. An example of the prescribed time TX is one hour. In one example, each of the sensors 41 to 48 stores the detection result detected at a predetermined sampling period at a predetermined time TX, and outputs the detection result averaged at the predetermined time TX to the refrigerant leakage determination device 60. The sensors 41 to 48 may output detection results detected at timings determined at predetermined times TX to the refrigerant leakage determination device 60.

The data storage unit 62 is electrically connected to the data acquisition unit 61. The data storage section 62 is supplied with data input from the data acquisition section 61. The data storage unit 62 stores data from the data acquisition unit 61. In one example, the data storage unit 62 sequentially stores the data from the data acquisition unit 61 in time series. The data storage unit 62 of the present embodiment is configured as a recording medium incorporated in the refrigerant leakage determination device 60. In this case, the data storage unit 62 may include, for example, a nonvolatile memory and a volatile memory. The data storage unit 62 may be a recording medium provided outside the refrigerant leakage determination device 60 or outside the refrigeration apparatus 1. In this case, the data storage section 62 may include at least one of a USB (universal serial bus) memory, an SD (secure data) memory card, and an HDD (hard disk drive) recording medium.

The preprocessing unit 63 removes, from the time-series data, data that interferes with the determination of the presence or absence of refrigerant leakage or the prediction of the occurrence timing of refrigerant leakage, and fills the removed data interval with substitute data. The pretreatment unit 63 includes a first treatment unit 63a and a second treatment unit 63 b. The data constituting the disturbance includes, for example, data of a momentary fluctuation immediately after the start of the compressor 11, data of a temporally discontinuous section, and the like.

The first processing unit 63a is electrically connected to the data storage unit 62, and the second processing unit 63b is electrically connected to the first processing unit 63 a. The first processing unit 63a extracts a section to be filled with the substitute data. The section includes, for example, at least one of a section in which the refrigeration apparatus 1 is stopped, a section immediately after the compressor 11 is started, a section immediately after the compressor 11 is stopped, and a section immediately after the operation of the compressor 11 is switched. In the present embodiment, the first processing unit 63a extracts all of the section in which the refrigeration apparatus 1 is stopped, the section immediately after the start of the compressor 11, the section immediately after the stop of the compressor 11, and the section immediately after the switching of the operation of the compressor 11.

The second processing unit 63b inputs the substitute data to the section extracted by the first processing unit 63 a. These substitute data are values before and after the section extracted by the first processing unit 63a or a predetermined representative value. For example, when the first processing unit 63a extracts a section in which the refrigeration apparatus 1 is stopped, the second processing unit 63b sets any one of the values before and after the section in which the refrigeration apparatus 1 is stopped as the substitute data. Here, data in a section where the data is stopped, i.e., temporally discontinuous, is regarded as "0", for example. When the first processing unit 63a extracts the section immediately after the start of the compressor 11, the second processing unit 63b sets the value immediately after the start of the compressor 11 as the substitute data. The value immediately after the start of the compressor 11 may be an average value of data in a predetermined period after the section immediately after the start of the compressor 11, or may be data at a time immediately after the section immediately after the start of the compressor 11. When the first processing unit 63a extracts a section immediately after the operation of the compressor 11 is stopped, the second processing unit 63b sets the value of the section immediately before the section immediately after the operation of the compressor 11 as the substitute data. The value of the section immediately before the section immediately after the stop of the operation of the compressor 11 may be an average value of data of the section immediately before the section immediately after the stop of the compressor 11, that is, the section immediately before the stop operation of the compressor 11, or may be data of the time immediately before the stop operation of the compressor 11. When the first processing unit 63a extracts the section immediately after the operation of the compressor 11 is switched, the second processing unit 63b sets any one of the values of the sections before and after the section immediately after the operation of the compressor 11 is switched as the substitute data. Any one of the values of the sections before and after the section immediately after the switching of the operation of the compressor 11 may be an average value of the data of any one of the sections before and after the section immediately after the switching of the operation of the compressor 11, or may be data at a predetermined timing of any one of the sections before and after the section immediately after the switching of the operation of the compressor 11. As a method of calculating the substitute data, a value calculated by performing interpolation processing (for example, linear interpolation) on data before and after the section filled with the substitute data may be used as the substitute data.

The refrigerant leakage determination unit 64 is electrically connected to the preprocessing unit 63. The refrigerant leakage determination unit 64 determines whether or not there is refrigerant leakage, or predicts the timing of refrigerant leakage, using the data processed by the preprocessing unit 63. The refrigerant leakage determination unit 64 includes a calculation unit 66 and a determination unit 67.

The calculation unit 66 calculates the first index value and the second index value so as to calculate the degree of deviation of the refrigerant circuit 20 from the normal state. The normal state of the refrigerant circuit 20 means, for example, that the amount of refrigerant sealed in the refrigerant circuit 20 (refrigerant charge amount) is within an appropriate range. The calculation unit 66 calculates the first index value based on the data relating to the operation of the refrigeration apparatus 1 in the first period among the data relating to the operation of the refrigeration apparatus 1. The calculation unit 66 calculates the second index value based on data relating to the operation of the refrigeration apparatus 1 in a second period having a length different from that of the first period, among the data relating to the operation of the refrigeration apparatus 1. The calculation unit 66 calculates the degree of deviation of the refrigerant circuit 20 from the normal state based on the first index value and the second index value. In the present embodiment, the calculation unit 66 calculates the degree of deviation of the refrigerant circuit 20 from the normal state based on the degree of deviation of the first index value and the second index value. The calculation unit 66 outputs the calculation result to the determination unit 67.

The determination unit 67 determines whether or not there is refrigerant leakage or predicts the timing of refrigerant leakage, based on the degree of deviation of the refrigerant circuit 20 from the normal state calculated by the calculation unit 66. The determination unit 67 outputs the determination result or the prediction result to the output unit 65.

Here, the presence or absence of refrigerant leakage does not mean whether or not there is a slight amount of refrigerant leakage, but means whether or not the amount of refrigerant leakage per unit time is equal to or greater than a first threshold value. An example of the first threshold value is a refrigerant leakage amount to the extent that an abnormality occurs in the refrigeration apparatus 1 due to refrigerant leakage, and is determined in advance by an experiment or the like. An example of an abnormality of the refrigeration apparatus 1 is a case where the temperature of the compressor 11 becomes too high because the compressor 11 cannot be cooled because the refrigerant filling amount is less than the lower limit value of the appropriate range. The refrigerant leakage occurrence timing may be, for example, a timing at which the refrigerant filling amount is less than the lower limit value of the appropriate range, or a timing at which the temperature of the compressor 11 becomes equal to or higher than the second threshold value due to the fact that the compressor 11 cannot be cooled because the refrigerant filling amount is less than the lower limit value of the appropriate range. An example of the second threshold value is a temperature at which abnormality such as burn is likely to occur in the compression mechanism section of the compressor 11, and is determined in advance by an experiment or the like.

The output unit 65 is electrically connected to the data storage unit 62 and the notification unit 52. The output unit 65 outputs the determination result of whether or not there is a refrigerant leak or the prediction result of the refrigerant leak occurrence timing to the data storage unit 62 and the notification unit 52. The notification unit 52 displays, for example, the determination result of whether or not there is a refrigerant leak or the prediction result of the refrigerant leak occurrence timing on the display 53. Further, the output section 65 has a wireless communication section including an antenna. The output unit 65 can communicate with a terminal of a manager (the manager terminal 70) through a wireless communication unit. The output unit 65 outputs the result of determination as to whether or not there is a refrigerant leak or the result of prediction of the timing of occurrence of a refrigerant leak to the terminal 70 for the manager. The administrator terminal 70 may be a portable communication device such as a smartphone or a tablet computer, or may be a desktop personal computer.

Next, the details of the determination of whether or not there is a refrigerant leak or the prediction of the timing of occurrence of a refrigerant leak by the refrigerant leak determination unit 64 will be described.

The calculation unit 66 calculates a first index value from a moving average of the data relating to the operation of the refrigeration apparatus 1 in the first period, and calculates a second index value from a moving average of the data relating to the operation of the refrigeration apparatus 1 in the second period, using the data relating to the operation of the refrigeration apparatus 1 stored in the data storage unit 62. The calculation unit 66 calculates the first index value and the second index value using data of the first period and the second period before the time point of performing the processing. The calculation unit 66 calculates the degree of deviation between the first index value and the second index value. In the present embodiment, the data in the first period is data in one day, and the data in the second period is data in ten days. In the present embodiment, the sampling period is set to one hour, and data relating to the operation of the refrigeration apparatus 1 is acquired for each hour. Therefore, the data of the first period and the data of the second period can be represented not only by the length of the period but also by the number of data, and data of one day refers to twenty-four data, and data of ten days refers to twenty-hundred-forty data.

The first index value and the second index value are discharge-side refrigerant temperature ratios. The discharge-side refrigerant temperature ratio is an example of a discharge-side refrigerant temperature index, and is represented by a ratio of a predicted value of the discharge-side refrigerant temperature of the compressor 11 to an actual measured value of the discharge-side refrigerant temperature of the compressor 11. In the present embodiment, the ratio of the actual measurement value of the discharge-side refrigerant temperature of the compressor 11 to the predicted value of the discharge-side refrigerant temperature of the compressor 11 is defined as the discharge-side refrigerant temperature ratio.

The calculation unit 66 calculates the discharge-side refrigerant temperature ratio as data relating to the operation of the refrigeration apparatus 1. Specifically, the calculation unit 66 calculates a predicted value of the discharge-side refrigerant temperature of the compressor 11 and an actual measured value of the discharge-side refrigerant temperature of the compressor 11, and calculates a discharge-side refrigerant temperature ratio as a ratio of the calculated actual measured value of the discharge-side refrigerant temperature of the compressor 11 to the predicted value of the discharge-side refrigerant temperature of the compressor 11.

The calculation unit 66 calculates a predicted value of the discharge-side refrigerant temperature of the compressor 11 by regression analysis using, as variables, at least one of the condensation temperature, the evaporation temperature, the opening degree of the first expansion valve 14A, the opening degree of the second expansion valve 14B, the operating frequency of the compressor 11, and the rotation speed of the compressor 11 when the refrigerant filling amount to be filled into the refrigerant circuit 20 is within an appropriate range, for example, according to the power supply frequency and the power supply voltage of the power supply of the supply source configured to supply electric power to the refrigeration apparatus 1.

Specifically, in a transportation refrigeration system such as a sea container, the power supply frequency and the power supply voltage of a power supply at a terminal such as a port may be different from those of a ship. In one example, the power supply frequency of the terminal's power supply is 50Hz and the power supply voltage is nominally 380V 10%. The power frequency of the ship's power supply is 60Hz and the power supply voltage is rated at 440V ± 10%. Examples of the combination of the power supply frequency and the power supply voltage include a first combination to a sixth combination. In the first combination, the power supply frequency is 50Hz, and the power supply voltage is 342V (lower limit value of power supply voltage in the case where the power supply frequency is 50 Hz). In the second combination, the power supply frequency is 50Hz, and the power supply voltage is 380V (the middle value of the power supply voltage in the case where the power supply frequency is 50 Hz). In the third combination, the power supply frequency is 50Hz, and the power supply voltage is 418V (the upper limit value of the power supply voltage when the power supply frequency is 50 Hz). In the fourth combination, the power supply frequency is 60Hz, and the power supply voltage is 396V (lower limit value of the power supply voltage in the case where the power supply frequency is 60 Hz). In the fifth combination, the power supply frequency is 60Hz, and the power supply voltage is 440V (the middle value of the power supply voltage in the case where the power supply frequency is 60 Hz). In the sixth combination, the power supply frequency is 60Hz, and the power supply voltage is 484V (the upper limit value of the power supply voltage when the power supply frequency is 60 Hz). The calculation unit 66 calculates predicted values of the discharge-side refrigerant temperature of the compressor 11 for the first combination to the sixth combination, respectively. The number of combinations of the power supply frequency and the power supply voltage can be changed arbitrarily.

The calculation unit 66 calculates an actual measurement value of the discharge-side refrigerant temperature of the compressor 11 based on a signal from the discharge temperature sensor 41. For example, as the amount of refrigerant leakage per unit time from the refrigerant circuit 20 increases, the actual measurement value of the discharge-side refrigerant temperature of the compressor 11 becomes higher than the predicted value of the discharge-side refrigerant temperature of the compressor 11. Therefore, the degree of deviation of the actual measured value of the discharge-side refrigerant temperature of the compressor 11 from the predicted value of the discharge-side refrigerant temperature of the compressor 11 has a correlation with the amount of refrigerant leakage per unit time.

The calculation unit 66 calculates a discharge-side refrigerant temperature ratio (hereinafter referred to as "first refrigerant temperature ratio") in a first period as a first index value, and the calculation unit 66 calculates a discharge-side refrigerant temperature ratio (hereinafter referred to as "second refrigerant temperature ratio") in a second period as a second index value. As an example, the graph of fig. 4 (a) shows the respective evolutions of the first refrigerant temperature ratio and the second refrigerant temperature ratio. As shown in fig. 4 (a), the degree of the deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio was small before 7 months and 9 days, but the degree of the deviation was gradually increased after 7 months and 9 days.

The calculation unit 66 calculates, for example, a degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio. In the present embodiment, the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio is represented by the ratio of the first refrigerant temperature ratio to the second refrigerant temperature ratio. As the ratio becomes larger, the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio becomes larger. The degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio may be represented by a difference between the first refrigerant temperature ratio and the second refrigerant temperature ratio. As the difference becomes larger, the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio becomes larger. As an example, the graph of fig. 4 (b) shows the progression of the degree of deviation of the first refrigerant temperature ratio and the second refrigerant temperature ratio. As shown in fig. 4 (b), the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio was about 1.00 before 7 months and 9 days. It is understood that the degree of separation between the first refrigerant temperature ratio and the second refrigerant temperature ratio gradually increases after 7 months and 9 days.

When the degree of separation between the first refrigerant temperature ratio and the second refrigerant temperature ratio is equal to or greater than the threshold XT, the determination unit 67 determines that refrigerant leakage is occurring. The threshold XT is a value for determining whether or not refrigerant leakage is occurring to such an extent that an abnormality occurs in the refrigeration apparatus 1, and is set in advance by an experiment or the like.

The determination unit 67 predicts the refrigerant leak occurrence period based on the change tendency of the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio. Specifically, for example, the calculation unit 66 calculates the degree of deviation between the daily first refrigerant temperature ratio and the daily second refrigerant temperature ratio, and outputs the calculated degree of deviation to the determination unit 67. The determination unit 67 obtains the change tendency of the degree of deviation from the daily degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio, for example. The determination unit 67 predicts the refrigerant leak occurrence period based on the information indicating that the degree of deviation has an increasing tendency and the slope of the degree of deviation. More specifically, the determination unit 67 predicts a period in which the degree of separation reaches the threshold XT from the slope of the degree of separation between the first refrigerant temperature ratio and the second refrigerant temperature ratio. The determination unit 67 may calculate the slope of the degree of separation by regression analysis, for example, or may calculate the slope of the degree of separation from a straight line connecting the degrees of separation in two predetermined periods. In one example, as shown in fig. 4 (b), the determination unit 67 predicts the degree of separation after 7/16 th day from the degree of separation between the first refrigerant temperature ratio and the second refrigerant temperature ratio between 7/16 th day (the dotted line portion in fig. 4 (b)). The determination unit 67 predicts the refrigerant leakage occurrence period based on a comparison between the progress of the degree of deviation after 7 months and 16 days and the threshold XT.

With reference to fig. 5, a specific processing procedure of the refrigerant leakage determination device 60 for determining whether or not there is refrigerant leakage or predicting the timing of occurrence of refrigerant leakage will be described. This processing is performed, for example, in at least one of the following cases: when there is a request from the user; when the power of the refrigeration apparatus 1 or the refrigerant leakage determination device 60 becomes an on state; when the transportation of the freezer 1 is completed; when the pre-use inspection of the refrigeration apparatus 1 is performed. In the present embodiment, the refrigerant leakage determination device 60 performs the determination of whether or not there is refrigerant leakage or the prediction of the refrigerant leakage occurrence timing in each of the following cases: when there is a request from the user; when the power supply of the refrigeration apparatus 1 or the refrigerant leakage determination device 60 is in an on state; when the transportation of the freezer 1 is completed; when the pre-use inspection of the refrigeration apparatus 1 is performed.

In step S11, the refrigerant leakage determination device 60 calculates the first refrigerant temperature ratio and the second refrigerant temperature ratio based on the data relating to the operation of the refrigeration apparatus 1, and the process proceeds to step S12. In step S12, the refrigerant leakage determination device 60 calculates the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio, and proceeds to step S13.

In step S13, the refrigerant leakage determination device 60 determines whether or not the degree of separation between the first refrigerant temperature ratio and the second refrigerant temperature ratio is equal to or greater than a threshold XT. If the determination in step S13 is affirmative, the refrigerant leakage determination device 60 determines in step S14 that refrigerant leakage is occurring, and proceeds to step S15. In step S15, the refrigerant leakage determination device 60 communicates the determination result with at least one of the display 53 and the terminal 70 for the manager, and once ends the process. In step S15, the display 53 and the manager terminal 70 notify the determination result of whether or not there is a refrigerant leak or the prediction result of the refrigerant leak occurrence timing when there is at least one of: when there is a request from the user; when the power supply of the refrigeration apparatus 1 or the refrigerant leakage determination device 60 is in an on state; when the transportation of the freezer 1 is completed; when the pre-use inspection of the refrigeration apparatus 1 is performed. In the present embodiment, the display 53 and the manager terminal 70 notify the determination result of whether or not there is a refrigerant leak or the prediction result of the refrigerant leak occurrence timing in each of the following cases: when there is a request from the user; when the power supply of the refrigeration apparatus 1 or the refrigerant leakage determination device 60 is in an on state; when the transportation of the freezer 1 is completed; when the pre-use inspection of the refrigeration apparatus 1 is performed. In step S15, communication with the notification unit 52 may be performed instead of the display 53. In the case where the notification unit 52 includes a speaker, the notification unit 52 may notify the determination result of whether or not there is a refrigerant leak or the prediction result of the refrigerant leak occurrence timing through the speaker.

If the determination at step S13 is negative, the refrigerant leakage determination device 60 calculates the tendency of the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio to change at step S16, and proceeds to step S17.

In step S17, the refrigerant leakage determination device 60 predicts the refrigerant leakage occurrence timing from the slope of the change in the degree of deviation of the first refrigerant temperature ratio and the second refrigerant temperature ratio, and proceeds to step S18. In step S18, the refrigerant leakage determination device 60 communicates the prediction result with at least one of the display 53 and the terminal 70 for the manager, and once ends the process. As described above, in the flowchart shown in fig. 5, the refrigerant leakage determination device 60 predicts the refrigerant leakage occurrence timing after determining whether there is refrigerant leakage.

The refrigerant leakage determination method of the refrigerant leakage determination device 60 described above has a data holding step, a first calculation step, a second calculation step, and a determination step. This will be explained below.

The data storage step is a step of storing data relating to the operation of the refrigeration apparatus 1. In one example, the data storage step stores data from the data acquisition unit 61 related to the operation of the refrigeration apparatus 1 in the data storage unit 62 as time-series data.

The first calculation step is a step of calculating a first index value from data relating to the operation of the refrigeration apparatus 1 in the first period, and calculating a second index value from data relating to the operation of the refrigeration apparatus 1 in the second period. In one example, the first calculation step is performed by the calculation unit 66. The first calculation step is a step of calculating the first index value from the moving average of the data relating to the operation of the refrigeration apparatus 1 in the first period, and calculating the second index value from the moving average of the data relating to the operation of the refrigeration apparatus 1 in the second period. In one example, the first calculation step includes a preprocessing step in which data that interferes with the determination of the presence or absence of refrigerant leakage or the prediction of the timing of occurrence of refrigerant leakage is deleted by the preprocessing unit 63 and is filled with substitute data. Describing the relationship between the first calculation step and fig. 5, step S11 in fig. 5 corresponds to the first calculation step.

The second calculation step is a step of calculating the degree of deviation of the refrigerant circuit 20 from the normal state based on the first index value and the second index value. In one example, the second calculation step is performed by the calculation unit 66. Describing the relationship between the second calculation step and fig. 5, step S12 in fig. 5 corresponds to the second calculation step.

The determination step is a step of determining whether there is refrigerant leakage or predicting the timing of occurrence of refrigerant leakage, based on the degree of deviation of the refrigerant circuit 20 from the normal state. In one example, in the determination step, it is determined that the refrigerant leakage has occurred when the second index value is set to the normal state of the refrigerant circuit 20 and the degree of deviation of the first index value from the second index value is equal to or greater than a certain threshold value. In the determination step, it is predicted when the degree of deviation reaches a threshold value based on the change tendency of the degree of deviation of the first index value from the second index value, thereby predicting the refrigerant leak occurrence period. Describing the relationship between the determination steps and fig. 5, steps S13 to S18 in fig. 5 correspond to the determination steps.

Next, the operation of the present embodiment will be described.

The refrigerant leakage determination device 60 calculates a second index value by a moving average based on data relating to the operation of the refrigeration apparatus 1 in the second period, and sets the calculated second index value as a reference. In the present embodiment, the data relating to the operation of the refrigeration apparatus 1 in the second period is data relating to the operation of the refrigeration apparatus 1 for a long period of time, such as ten days to thirty days, and therefore, the influence of the fluctuation relating to the operation of the refrigeration apparatus 1 for a short period of time, such as one day, is small.

The refrigerant leakage determination device 60 calculates the first index value by a moving average from the data relating to the operation of the refrigeration apparatus 1 in the first period. In the present embodiment, the data relating to the operation of the refrigeration apparatus 1 in the first period is data relating to the operation of the refrigeration apparatus 1 in a short period of time such as one day, and therefore, the influence of recent fluctuations relating to the operation of the refrigeration apparatus 1 is large.

In this way, by monitoring how much the first index value having a large influence on the fluctuation in the operation of the refrigeration apparatus 1 deviates from the second index value with reference to the second index having a small influence on the recent fluctuation in the operation of the refrigeration apparatus 1, it is possible to easily extract the fluctuation in the operation of the refrigeration apparatus 1. Thus, when refrigerant leakage occurs, the refrigerant leakage determination device 60 can determine that refrigerant leakage has occurred because the first index value is significantly different from the second index value. Further, the refrigerant leakage determination device 60 can predict the refrigerant leakage occurrence period by acquiring the tendency of change in the degree of deviation of the first index value from the second index value and predicting the evolution of the degree of deviation.

According to the present embodiment, the following effects can be obtained.

(1) The calculation unit 66 calculates a first index value calculated from data relating to the operation of the refrigeration apparatus 1 in a first period and a second index value calculated from data relating to the operation of the refrigeration apparatus 1 in a second period having a length different from that of the first period, and calculates a state of deviation of the refrigerant circuit 20 from the normal state based on the first index value and the second index value. The determination unit 67 determines whether there is refrigerant leakage or predicts the refrigerant leakage occurrence timing based on the degree of deviation of the refrigerant circuit 20 from the normal state. According to this configuration, the state of deviation of the refrigerant circuit 20 from the normal state can be calculated from the state of deviation of the first index value and the second index value calculated using the data relating to the operation of the refrigeration apparatus 1, including the normal operation such as the cooling operation and the defrosting operation of the refrigeration apparatus 1 and the operation of the pre-use inspection of the refrigeration apparatus 1. Thus, it is possible to determine whether or not cooling leakage occurs or to predict the timing of occurrence of refrigerant leakage, based on the deviated state of the refrigerant circuit 20 from the normal state. In this way, it is possible to determine whether there is refrigerant leakage or predict the timing of refrigerant leakage without performing a special operation for determining whether there is refrigerant leakage.

(2) The second index value calculated in the second period having a long period has a small influence on the fluctuation of the operation of the refrigeration apparatus 1, and the first index value calculated in the first period having a short period has a large influence on the fluctuation of the operation of the refrigeration apparatus 1. Therefore, in the present embodiment, the calculation unit 66 calculates the first index value and the second index value, and calculates the degree of deviation of the refrigerant circuit 20 from the normal state based on the degree of deviation of the first index value and the second index value. This makes it easy to extract the variation in the operation of the refrigeration apparatus 1, and it is possible to determine whether or not there is refrigerant leakage or to predict the timing of occurrence of refrigerant leakage from the variation in the operation of the refrigeration apparatus 1.

(3) The first index value is calculated from a moving average of data relating to the operation of the refrigeration apparatus 1 in the first period, and the second index value is calculated from a moving average of data relating to the operation of the refrigeration apparatus 1 in the second period. With this configuration, it is possible to determine whether or not there is a refrigerant leak or to predict the timing of occurrence of the refrigerant leak, based on the degree of deviation between the variation in the operation of the refrigeration apparatus 1 over a long period of time and the variation in the operation of the refrigeration apparatus 1 over a short period of time.

(4) When the amount of refrigerant sealed in the refrigerant circuit 20 (the refrigerant filling amount) is smaller than the appropriate range, the suction pressure of the compressor 11 decreases, and therefore, insufficient cooling by the refrigerant inside the compressor 11 occurs, and the temperature of the compressor 11 may become excessively high. That is, the discharge-side refrigerant temperature of the compressor 11 when the amount of refrigerant in the sealed refrigerant circuit 20 is smaller than the lower limit value of the appropriate range is higher than the discharge-side refrigerant temperature of the compressor 11 when the amount of refrigerant in the sealed refrigerant circuit 20 is within the appropriate range. Therefore, in the present embodiment, as the first index value and the second index value, a discharge-side refrigerant temperature ratio, which is a ratio of an actual measurement value of the discharge-side refrigerant temperature of the compressor 11 to a predicted value of the discharge-side refrigerant temperature of the compressor 11, is used. Therefore, it is possible to accurately determine whether or not there is refrigerant leakage or to predict the timing of occurrence of refrigerant leakage.

(5) The calculation unit 66 calculates the predicted refrigerant temperature from the power supply frequency and the power supply voltage, and calculates the first refrigerant temperature ratio and the second refrigerant temperature ratio from the power supply frequency and the power supply voltage. Thus, the first refrigerant temperature ratio and the second refrigerant temperature ratio can be calculated with higher accuracy, and therefore, it is possible to determine with high accuracy whether or not there is refrigerant leakage or to predict the timing of occurrence of refrigerant leakage.

(6) The preprocessing unit 63 removes data relating to the operation of the refrigeration apparatus 1, which is a disturbance when determining whether or not there is a refrigerant leak or predicting the timing of occurrence of a refrigerant leak, and fills the data with substitute data, thereby making it possible to accurately determine whether or not there is a refrigerant leak or predict the timing of occurrence of a refrigerant leak.

(7) When the first processing unit 63a extracts the section immediately after the start of the compressor 11, the second processing unit 63b sets the value immediately after the start of the compressor 11 as the substitute data. When the first processing unit 63a extracts a section immediately after the operation of the compressor 11 is stopped, the second processing unit 63b sets the value of the section immediately before the section immediately after the operation of the compressor 11 as the substitute data. When the first processing unit 63a extracts the section immediately after the operation of the compressor 11 is switched, the second processing unit 63b sets any one of the values of the sections before and after the section immediately after the operation of the compressor 11 is switched as the substitute data. According to this configuration, the data temporally close to the section extracted by the first processing unit 63a is used as the substitute data, and the degree of deviation between the actual data and the substitute data related to the operation of the refrigeration apparatus 1 can be reduced. Therefore, it is possible to accurately determine whether or not there is refrigerant leakage or to predict the timing of occurrence of refrigerant leakage.

(8) Since the occurrence of refrigerant leakage or the timing of refrigerant leakage is displayed on the display 53 of the refrigeration apparatus 1 or the administrator terminal 70 by the notification unit 52, the administrator or the operator of the refrigeration apparatus 1 can grasp the occurrence of refrigerant leakage or the timing of refrigerant leakage.

(modification example)

The description of the above embodiments is an example of the form that can be obtained by the refrigerant leakage determination device, the refrigeration device including the refrigerant leakage determination device, and the refrigerant leakage determination method according to the present disclosure, and is not intended to limit the form. The refrigerant leakage determination device, the refrigeration apparatus including the refrigerant leakage determination device, and the refrigerant leakage determination method according to the present disclosure can take, for example, a form of a modification of the above-described embodiment shown below and a form in which at least two modifications are combined without being contradictory to each other. In the following modifications, the same reference numerals as in the above-described embodiment are given to the same portions as those of the above-described embodiment, and the description thereof is omitted.

In the above embodiment, the degree of deviation between the first index value and the second index value is represented by the ratio of the first index value to the second index value, but the present invention is not limited thereto. The calculation method of the degree of deviation of the first index value from the second index value can be arbitrarily changed. In one example, the calculation unit 66 may calculate the degree of deviation between the first index value and the second index value based on at least one of a standard deviation, a skewness, a likelihood, a kurtosis, and an average using the first index value and the second index value.

In the above embodiment, the refrigerant leakage determination device 60 performs both the determination of whether or not there is a refrigerant leakage and the prediction of the timing of occurrence of the refrigerant leakage, but is not limited thereto. The refrigerant leakage determination device 60 may perform only the determination of whether there is refrigerant leakage. Further, the refrigerant leakage determination device 60 may also perform the prediction of the refrigerant leakage occurrence period when the degree of deviation between the first index value and the second index value is smaller than the threshold XT. In this case, the refrigerant leakage determination device 60 can omit the determination of whether there is refrigerant leakage.

In the above embodiment, the preprocessing unit 63 removes data that interferes with the determination of the presence or absence of refrigerant leakage or the prediction of the timing of occurrence of refrigerant leakage from the time-series data, and fills the section of the removed data with substitute data. The preprocessing unit 63 may remove only data that interferes with the determination of the presence or absence of refrigerant leakage or the prediction of the timing of occurrence of refrigerant leakage from the time series data. With this configuration, it is possible to accurately determine whether or not there is refrigerant leakage or to predict the timing of occurrence of refrigerant leakage.

In the above embodiment, instead of the discharge-side refrigerant temperature ratio, the first index value and the second index value may be calculated from a predicted value of the discharge-side refrigerant temperature or an actual measurement value of the discharge-side refrigerant temperature. In one example, the calculation unit 66 calculates a first index value from a moving average of the predicted values of the discharge-side refrigerant temperature in the first period, and calculates a second index value from a moving average of the predicted values of the discharge-side refrigerant temperature in the second period. In one example, the calculation unit 66 calculates the first index value from the moving average of the measured values of the discharge-side refrigerant temperature in the first period, and calculates the second index value from the moving average of the measured values of the discharge-side refrigerant temperature in the second period.

In the above embodiment, as the first index value and the second index value, a discharge-side refrigerant pressure ratio, which is a ratio of an actual measurement value of the discharge-side refrigerant pressure of the compressor 11 to a predicted value of the discharge-side refrigerant pressure of the compressor 11, may be used instead of the discharge-side refrigerant temperature ratio. As the first index value, the calculation unit 66 calculates the discharge-side refrigerant pressure ratio (hereinafter referred to as "first refrigerant pressure ratio") in the first period, and as the second index value, the calculation unit 66 calculates the discharge-side refrigerant pressure ratio (hereinafter referred to as "second refrigerant pressure ratio") in the second period. The calculation unit 66 calculates the degree of deviation between the first refrigerant pressure ratio and the second refrigerant pressure ratio. The determination unit 67 determines that refrigerant leakage is occurring when the degree of deviation between the first refrigerant pressure ratio and the second refrigerant pressure ratio is equal to or greater than a predetermined threshold value. Further, the determination unit 67 predicts the refrigerant leakage occurrence period based on the inclination of the change in the degree of deviation between the first refrigerant pressure ratio and the second refrigerant pressure ratio. Instead of the discharge-side cooling temperature ratio, a ratio of an actual measured value of the degree of superheat of the suction gas refrigerant sucked into the compressor 11 to a predicted value of the degree of superheat of the suction gas refrigerant sucked into the compressor 11, or a ratio of an actual measured value of the degree of subcooling of the liquid refrigerant at the outlet of the condenser 12 to a predicted value of the degree of subcooling of the liquid refrigerant at the outlet of the condenser 12 may be used.

In the above modification, instead of the discharge-side refrigerant pressure ratio, the first index value and the second index value may be calculated from a predicted value of the discharge-side refrigerant pressure of the compressor 11 or an actual measurement value of the discharge-side refrigerant pressure of the compressor 11. In one example, the calculation unit 66 calculates the first index value from the moving average of the predicted values of the refrigerant pressure on the discharge side of the compressor 11 in the first period, and the calculation unit 66 calculates the second index value from the moving average of the predicted values of the refrigerant pressure on the discharge side of the compressor 11 in the second period. In one example, the calculation unit 66 calculates the first index value from the moving average of the measured values of the discharge-side refrigerant pressure of the compressor 11 in the first period, and calculates the second index value from the moving average of the measured values of the discharge-side refrigerant pressure of the compressor 11 in the second period.

In the above embodiment, the data storage unit 62 may be a server located outside the refrigeration apparatus 1 and communicably connected to the refrigeration apparatus 1. One example of the server includes a cloud server. That is, the refrigerant leakage determination device 60 transmits the data acquired by the data acquisition unit 61 to the server, thereby storing the data in the server.

In the above embodiment, the refrigerant leakage determination device 60 and the notification unit 52 are provided separately, but the present invention is not limited thereto, and the refrigerant leakage determination device 60 may have the notification unit 52.

In the above-described embodiment, the configuration of the transport refrigeration apparatus has been described as the refrigeration apparatus 1, but the configuration of the refrigeration apparatus is not limited to this. For example, the present invention can also be applied to a freezer for a stationary warehouse. When the refrigeration apparatus 1 is applied to a refrigeration apparatus other than a transport refrigeration apparatus, the refrigerant leakage determination device 60 determines whether or not there is refrigerant leakage or predicts the timing of occurrence of refrigerant leakage in at least one of the following cases: when there is a request from the user; when the power supply of the refrigeration apparatus 1 or the refrigerant leakage determination device 60 is in an on state; when the pre-use inspection of the refrigeration apparatus 1 is performed. Further, the notification unit 52 notifies the determination result of whether or not there is a refrigerant leak or the prediction result of the refrigerant leak occurrence timing in at least one of the following cases: when there is a request from the user; when the power supply of the refrigeration apparatus 1 or the refrigerant leakage determination device 60 is in an on state; when the pre-use inspection of the refrigeration apparatus 1 is performed.

In the above-described embodiment, the structure of the refrigeration apparatus 1 for a container is described, but the structure of the refrigeration apparatus is not limited to this. For example, as shown in fig. 6, a refrigeration device may be used as the air conditioner 80. The air conditioner 80 includes a refrigerant circuit 90, and the refrigerant circuit 90 connects an outdoor unit 80A installed outdoors to a wall-mounted indoor unit 80B installed on an indoor wall surface or the like via a refrigerant pipe 91.

The outdoor unit 80A includes a compressor 81 whose capacity is variable by changing the operating frequency, a four-way selector valve 82, an outdoor heat exchanger 83, an expansion valve 84, an outdoor fan 85, an outdoor control device 86, and the like. The compressor 81 is, for example, an oscillating piston type compressor, and includes a compression mechanism, a motor, a crankshaft that transmits a driving force of the motor to the compression mechanism, and the like. The outdoor heat exchanger 83 exchanges heat between the outside air and the refrigerant, and may be, for example, a fin-and-tube heat exchanger. The expansion valve 84 is, for example, an electronic expansion valve. The outdoor fan 85 has a motor with a variable rotation speed as a drive source and an impeller connected to an output shaft of the motor. An example of the impeller is a propeller fan. The outdoor fan 85 rotates an impeller by a motor to generate an airflow of outdoor air flowing through the outdoor heat exchanger 83. The outdoor control device 86 is electrically connected to the motor of the compressor 81, the four-way selector valve 82, the expansion valve 84, and the motor of the outdoor fan 85, and controls the operations thereof.

The indoor unit 80B includes an indoor heat exchanger 87, an indoor fan 88, an indoor controller 89, and the like. The indoor heat exchanger 87 exchanges heat between the indoor air and the refrigerant, and may be a fin-and-tube heat exchanger, for example. The indoor fan 88 has a motor with a variable rotation speed as a drive source and an impeller connected to an output shaft of the motor. An example of the impeller is a cross flow fan. The indoor control device 89 is electrically connected to the indoor fan 88 and controls the operation of the indoor fan 88.

The refrigerant circuit 90 is configured to be able to perform a vapor compression refrigeration cycle by connecting the compressor 81, the four-way selector valve 82, the outdoor heat exchanger 83, the expansion valve 84, the indoor heat exchanger 87, and the accumulator 81a in an annular shape by the refrigerant pipe 91 and switching the four-way selector valve 82, so that the refrigerant can circulate reversibly.

That is, by switching the four-way selector valve 82 to the cooling mode connection state (the state shown by the solid lines), the refrigerant circuit 90 forms a refrigeration cycle in which the refrigerant circulates through the compressor 81, the four-way selector valve 82, the outdoor heat exchanger 83, the expansion valve 84, the indoor heat exchanger 87, the four-way selector valve 82, the accumulator 81a, and the compressor 81 in this order. Thus, the air conditioner 80 performs a cooling operation in which the outdoor heat exchanger 83 functions as a condenser and the indoor heat exchanger 87 functions as an evaporator. Further, by switching the four-way selector valve 82 to the heating mode connection state (the state shown by the broken lines), the refrigerant circuit 90 forms a heating cycle in which the refrigerant circulates in the accumulator 81a, the compressor 81, the four-way selector valve 82, the indoor heat exchanger 87, the expansion valve 84, the outdoor heat exchanger 83, the four-way selector valve 82, and the compressor 81 in this order. Thus, the air conditioner 80 performs a heating operation, and in the heating operation, the indoor heat exchanger 87 functions as a condenser and the outdoor heat exchanger 83 functions as an evaporator.

In the air conditioner 80, for example, the refrigerant leakage determination device 60 (not shown in fig. 6) is provided in any one of the outdoor control device 86 and the indoor control device 89. The notification unit 52 (not shown in fig. 6) is provided in, for example, a remote controller of the air conditioner 80.

In the above embodiment, the refrigeration apparatus 1 includes the refrigerant leakage determination device 60, but the configuration of the refrigeration apparatus 1 is not limited to this. For example, the refrigeration apparatus 1 may omit the refrigerant leakage determination device 60. The refrigerant leakage determination device 60 may be provided separately from the refrigeration apparatus 1. In one example, the refrigerant leakage determination device 60 may be provided in a server that can communicate with the refrigeration apparatus 1. In this case, the refrigeration apparatus 1 communicates with the refrigerant leakage determination device 60 to obtain a determination result of whether or not there is refrigerant leakage or a prediction result of the timing of occurrence of refrigerant leakage.

While the embodiments of the present apparatus have been described above, it should be understood that various changes in form and details may be made therein without departing from the spirit and scope of the present apparatus as set forth in the appended claims.

Claims

1. A refrigerant leakage determination device (60), the refrigerant leakage determination device (60) for determining refrigerant leakage of a refrigeration device (1), characterized in that,

The refrigeration device (1) includes a refrigerant circuit (20), and the refrigerant circuit (20) is configured to have a compressor (11), a condenser (12), a decompression device (14A, 14B), and an evaporator ( 13), and for refrigerant to circulate in the compressor (11), the condenser (12), the decompression device (14A, 14B) and the evaporator (3),

The refrigerant leakage determination device (60) includes:

a calculation unit (66) that calculates a degree of deviation from a normal state of the refrigerant circuit (20) based on data related to the operation of the refrigerating apparatus (1); and

A determination unit (67), which determines whether there is a refrigerant leak based on the calculation result of the calculation unit (66), or predicts the occurrence time of the refrigerant leak,

The calculating part (66) is configured as:

A first index value and a second index value are calculated based on the data related to the operation of the refrigeration device (1) in the first period among the data related to the operation of the refrigeration device (1). data calculation, the second index value is calculated from data related to the operation of the refrigeration apparatus (1) for a second period having a length different from that of the first period,

And according to the first index value and the second index value, the degree of deviation from the normal state of the refrigerant circuit (20) is calculated,

The determination unit (67) is configured to determine whether or not the refrigerant leak exists, or to predict the timing at which the refrigerant leak occurs, based on the degree of deviation of the refrigerant circuit (20) from a normal state.

2 . The refrigerant leakage determination device according to claim 1 , wherein: 2 .

The calculation unit (66) is configured to detect the degree of deviation of the refrigerant circuit (20) from a normal state based on the degree of deviation of the first index value and the second index value.

3. The refrigerant leakage determination device according to claim 1 or 2, wherein:

The data related to the operation of the refrigeration device (1) in the first period is data for one day,

The data related to the operation of the refrigerating apparatus (1) in the second period is data for ten days or more and thirty days or less.

4. The refrigerant leakage determination device according to claim 3, wherein:

The data related to the operation of the refrigeration device (1) in the first period is twenty-four data,

The data related to the operation of the refrigerating apparatus (1) in the second period is 240 or more and 720 or less data.

5. The refrigerant leakage determination device according to any one of claims 1 to 4, wherein:

The calculating part (66) is configured as:

calculating the first index value from a moving average of data related to the operation of the refrigeration device (1) in the first period;

And the said 2nd index value is calculated based on the moving average of the data related to the operation of the said refrigerating apparatus (1) in the said 2nd period.

6. The refrigerant leakage determination device according to any one of claims 1 to 5, wherein:

The first index value and the second index value respectively include a predicted value of the refrigerant temperature on the discharge side of the compressor (11), an actual measured value of the refrigerant temperature on the discharge side of the compressor (11), and Either one of a discharge-side refrigerant temperature index calculated from a predicted value of the discharge-side refrigerant temperature of the compressor (11) and an actual measured value of the discharge-side refrigerant temperature of the compressor (11).

7. The refrigerant leakage determination device according to claim 5, wherein:

The calculating unit (66) is configured to calculate the discharge side cooling of the compressor (11) by regression analysis according to the power supply frequency and power supply voltage of a power supply configured as a supply source for supplying power to the refrigeration device (1). The predicted value of the temperature of the refrigerant is obtained, and the regression analysis is performed on the condensation temperature, the evaporation temperature, the expansion valve (14A) of the pressure reducing device when the amount of refrigerant to be charged into the refrigerant circuit (20) is within an appropriate range. , 14B), at least one of the operating frequency of the compressor (11), and the rotational speed of the compressor (11) is set as a variable.

8. The refrigerant leakage determination device according to any one of claims 1 to 7, wherein:

The calculating unit (66) is configured to remove data of a section in which the refrigeration apparatus (1) is stopped, data of a section immediately after the compressor (11) is started, and immediately after the compressor (11) is stopped. The first index value and the second index value are calculated by at least one of the data of the section of the compressor (11) and the data of the section immediately after the operation of the compressor (11) is switched.

9. The refrigerant leakage determination device according to any one of claims 1 to 7, wherein:

The calculating unit (66) is configured to substitute the data of the section in which the refrigeration apparatus (1) is stopped, the data of the section immediately after the compressor (11) is started, and the compressor (11) with substitute data. The first index value and the second index value are calculated from at least one of the data of the section immediately after the stop and the data of the section immediately after the operation of the compressor (11) is switched.

10. The refrigerant leakage determination device according to claim 9, wherein:

The substitute data are the section in which the refrigeration device (1) is stopped, the section immediately after the compressor (11) is started, the section immediately after the compressor (11) is stopped, and the compressor (11) The value before and after the interval in which the substitute data is used, or a predetermined representative value in the interval immediately after switching of the operation.

11. The refrigerant leakage determination device according to any one of claims 1 to 10, wherein:

The calculating unit (66) is configured to calculate the result based on at least one of standard deviation, skewness, likelihood, kurtosis, and average using the first index value and the second index value. The degree of deviation between the first index value and the second index value.

12. The refrigerant leakage determination device according to any one of claims 1 to 11, wherein:

The refrigerating apparatus (1) further includes a notification unit (52) that notifies a determination result of the presence or absence of the refrigerant leakage or a prediction result of the occurrence time of the refrigerant leakage,

The notification unit (52) is configured to notify the determination result of the presence or absence of the refrigerant leakage or the prediction result of the occurrence time of the refrigerant leakage in at least one of the following cases: when there is a user request; when there is a user request; When the power supply of the refrigeration device (1) or the refrigerant leakage determination device (60) is turned on; when the pre-use inspection of the refrigeration device (1) is carried out.

13. A freezing device, characterized in that,

The refrigerant leakage determination device (60) according to any one of claims 1 to 12 is included.

14. The freezing apparatus of claim 13, wherein

The refrigerating device is a transportation refrigerating device (1),

The transport refrigeration device (1) further includes a notification unit (52) configured to notify a result of determination of the presence or absence of the refrigerant leakage or a prediction result of the occurrence time of the refrigerant leakage ,

The notification unit (52) is configured to notify the determination result of the presence or absence of the refrigerant leakage or the prediction result of the occurrence time of the refrigerant leakage in at least one of the following cases: when there is a user request; when there is a user request; When the power supply of the transportation refrigeration device (1) or the refrigerant leakage determination device (60) is turned on; when the transportation of the transportation refrigeration device (1) is completed; when the transportation is performed During the inspection before use of the refrigeration unit (1).

15. A method for determining refrigerant leakage of a refrigerating device (1), characterized in that:

The refrigerant leakage determination method includes the following steps:

storing data related to the operation of the freezing device (1);

A first index value is calculated based on data related to the operation of the refrigeration apparatus (1) in the first period, and the refrigeration apparatus (1) is calculated based on the data related to the refrigeration apparatus (1) in the second period whose length is different from the length of the first period. Calculate the second index value based on the operation-related data;

calculating the degree of deviation from the normal state of the refrigerant circuit (20) based on the first index value and the second index value; and

According to the degree of deviation of the refrigerant circuit (20) from the normal state, it is determined whether there is refrigerant leakage, or the timing of occurrence of refrigerant leakage is predicted.