JP2020056509A - Refrigerant leakage determination device, freezing device with refrigerant leakage determination device, and refrigerant leakage determination method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerant leakage determination device which does not require a special operation of a refrigerating device for determining the presence or absence of refrigerant leakage, a refrigerating device provided with the refrigerant leakage determination device, and a refrigerant leakage determination method. SOLUTION: A refrigerant leakage determination device 60 of a refrigerating device has a calculation unit 66 that calculates a degree of deviation from a normal state of a refrigerant circuit based on data related to the operation of the refrigerating device, and a refrigerant based on the calculation results of the calculation unit 66. It has a determination unit 67 that determines the presence or absence of leakage or predicts the timing of refrigerant leakage occurrence. The calculation unit 66 includes the first index value calculated from the data related to the operation of the refrigerating apparatus in the first period and the second index value calculated from the data related to the operation of the refrigerating apparatus in the second period among the data related to the operation of the refrigerating apparatus. The degree of deviation from the normal state of the refrigerant circuit is calculated based on the index value. The determination unit 67 determines the presence or absence of refrigerant leakage based on the degree of deviation from the normal state of the refrigerant circuit, or predicts the time when the refrigerant leakage occurs. [Selection diagram] Fig. 3

Description

  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.

  2. Description of the Related Art Conventionally, in an air conditioner in which an outdoor unit having a compressor and an indoor unit are connected by a refrigerant pipe to form a refrigeration cycle, a configuration for determining the presence or absence of refrigerant leakage is known (for example, see Patent Document 1). ). In such an air conditioner, the outside air temperature at the time of starting the compressor in the initial stage after the installation of the air conditioner, the discharge side temperature of the compressor when the air conditioner is operated under predetermined conditions, and the subsequent compressor The presence or absence of refrigerant leakage is determined by comparing the outside air temperature at the time of startup with the discharge-side temperature of the compressor when the air conditioner is operated under the same predetermined conditions.

JP 2013-204871 A

  In the conventional air conditioner, it is necessary to match the operating conditions of the air conditioner in the initial stage after the installation of the air conditioner and the operating conditions of the air conditioner thereafter in order to determine the presence or absence of the refrigerant leakage. It is necessary to perform a special operation in order to determine the presence or absence of the vehicle. For this reason, the air conditioner cannot normally operate over the period for determining whether there is refrigerant leakage. Note that the above problem is not limited to the air conditioner, but similarly occurs 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 for determining the presence or absence of refrigerant leakage, a refrigeration device including the refrigerant leakage determination device, and a refrigerant leakage determination method. is there.

  A refrigerant leakage determination device that solves this problem has a compressor, a condenser, a decompression device, and an evaporator, and determines refrigerant leakage in a refrigeration device that includes a refrigerant circuit configured to circulate refrigerant. A determination device, a calculation unit that calculates the degree of deviation from the normal state of the refrigerant circuit based on data related to the operation of the refrigeration device, and determines the presence or absence of refrigerant leakage based on the calculation result of the calculation unit, Or a determining unit for predicting a refrigerant leak occurrence time, wherein the calculating unit is configured to calculate, from among the data relating to the operation of the refrigeration apparatus, a first index calculated from data relating to the operation of the refrigeration apparatus during a first period. Calculating a degree of deviation from the normal state of the refrigerant circuit based on the value and a second index value calculated from data on the operation of the refrigeration apparatus in a second period having a different length from the first period. And said Tough, based on the degree of divergence from the normal state of the refrigerant circuit determines the presence of the refrigerant leakage, or to predict the refrigerant leakage occurrence time.

  According to this configuration, based on the degree of divergence between the first index value and the second index value calculated using the data related 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. The degree of deviation from the normal state of the refrigerant circuit can be calculated. Thereby, it is possible to determine whether or not there is a refrigerant leak, or to predict a refrigerant leak occurrence time. Data relating to the operation of the refrigeration apparatus is obtained, for example, by an operation including a normal operation of the refrigeration apparatus and an operation of a pre-use check of the refrigeration apparatus. Therefore, it is possible to determine the presence / absence of refrigerant leakage or predict the refrigerant leakage occurrence time without performing a special operation for determining refrigerant leakage.

  A refrigerant leakage determination method that solves this problem is a refrigerant leakage determination method for a refrigeration apparatus that includes a compressor, a condenser, a decompression device, and an evaporator, and includes a refrigerant circuit configured to circulate refrigerant. A data storing step of storing data relating to the operation of the refrigeration apparatus, and calculating a first index value from data relating to the operation of the refrigeration apparatus during a first period, wherein the first index value is different from the first period. A first calculation step of calculating a second index value from data relating to the operation of the refrigeration apparatus, and a normal operation of the refrigerant circuit based on the first index value and the second index value calculated in the first calculation step. A second calculating step of calculating the degree of deviation from the state, and determining whether there is refrigerant leakage based on the degree of deviation from the normal state of the refrigerant circuit, or estimating the refrigerant leakage occurrence time. Has a step, a.

  According to this configuration, based on the degree of divergence between the first index value and the second index value calculated using the data related 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. The degree of deviation from the normal state of the refrigerant circuit can be calculated. Thereby, it is possible to determine whether or not there is a refrigerant leak, or to predict a refrigerant leak occurrence time. Data relating to the operation of the refrigeration apparatus is obtained, for example, by an operation including a normal operation of the refrigeration apparatus and an operation of a pre-use check of the refrigeration apparatus. Therefore, it is possible to determine the presence / absence of refrigerant leakage or predict the refrigerant leakage occurrence time without performing a special operation for determining refrigerant leakage.

FIG. 1 is a configuration diagram conceptually showing a refrigeration apparatus in the refrigeration apparatus of the present embodiment. FIG. 2 is a block diagram showing an electrical configuration of the refrigeration apparatus. FIG. 2 is a block diagram showing an electrical configuration of a refrigerant leakage determination device of the refrigeration device. (A) is a graph showing an example of a transition of a refrigerant temperature ratio on the discharge side of the refrigerating apparatus, and (b) is a graph showing an example of a transition of a degree of deviation of a first index value from a second index value. 9 is a flowchart illustrating an example of a processing procedure of a refrigerant leakage determination process performed by the refrigerant leakage determination device. The block diagram which shows the freezing apparatus of a modified example notionally.

  Hereinafter, a refrigerating apparatus for transportation (hereinafter, simply referred to as “refrigerating apparatus 1”), which is an example of the refrigerating apparatus, will be described with reference to the drawings. The refrigeration apparatus 1 cools the inside of a warehouse such as a marine container, a container for a land transportation trailer, and the like. The inside of the casing of the refrigeration apparatus 1 is separated into an internal storage space for circulating the internal air and an external storage space for circulating the external air.

  As shown in FIG. 1, the refrigeration apparatus 1 includes a refrigerant circuit 20 in which a compressor 11, a condenser 12, an evaporator 13, and the like are connected by refrigerant pipes. The refrigerant circuit 20 includes a main circuit 21, a hot gas bypass circuit 22, and a liquid refrigerant bypass circuit 31.

The main circuit 21 includes 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, which are connected in series by a refrigerant pipe.
As shown in FIG. 1, the compressor 11, the condenser 12, the first expansion valve 14 </ b> A, the outside blower 15 that circulates outside air to the condenser 12, and the like are stored in the outside storage space. Further, the evaporator 13, the in-compartment blower 16 for circulating the in-compartment air to the evaporator 13, and the like are accommodated in the in-compartment accommodation space.

  As the compressor 11, for example, a rotary compressor or a scroll compressor can be used. The rotation speed of the compressor 11 is controlled by controlling the operation frequency by the inverter, so that the operation capacity is variable.

  As the condenser 12 and the evaporator 13, a fin-and-tube heat exchanger can be used. The condenser 12 exchanges heat between the outside air supplied by the outside blower 15 and the refrigerant circulating in the condenser 12. The evaporator 13 exchanges heat between the internal air supplied by the internal blower 16 and the refrigerant circulating in the evaporator 13. An example of the outside fan 15 and the inside fan 16 is a propeller fan. Below the evaporator 13, a drain pan 28 is provided. In the drain pan 28, frost and ice blocks peeled off from the evaporator 13 and dew condensation water condensed from the air are collected.

As the first expansion valve 14A, for example, an electric expansion valve configured to be variable in opening degree by a pulse motor can be used.
The high-pressure gas pipe 23 connecting the compressor 11 and the condenser 12 is provided with a first on-off valve 17A and a check valve 18 in order in the flow direction of the refrigerant. As the first opening / closing valve 17A, for example, an electric expansion valve configured to be variable in opening degree by a pulse motor can be used. The check valve 18 allows the flow of the refrigerant in the direction of the arrow shown in FIG.

  In the high-pressure liquid pipe 24 connecting the condenser 12 and the first expansion valve 14A, a receiver 29, a second opening / closing valve 17B, a dryer 30, and a supercooling heat exchanger 27 are sequentially provided in the refrigerant flow direction. As the second opening / closing valve 17B, for example, an openable / closable solenoid valve can be used.

  The subcooling heat exchanger 27 has a primary side passage 27a and a secondary side passage 27b which are 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 side passage 27b is provided in the liquid refrigerant bypass circuit 31. The liquid refrigerant bypass circuit 31 is a bypass circuit that connects the high-pressure liquid pipe 24 and an intermediate pressure section (not shown) in the compression mechanism section in the compressor 11. Between the high-pressure liquid pipe 24 and the secondary passage 27b in the liquid refrigerant bypass circuit 31, a third on-off valve 17C and a second expansion valve 14B, which is an example of a throttle device, are sequentially arranged in the flow direction of the high-pressure liquid refrigerant. It is connected. With this 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, and has a lower temperature than the liquid refrigerant flowing through the high-pressure liquid pipe 24. And flows into the secondary side passage 27b. Therefore, the high-pressure liquid refrigerant flowing through the primary side passage 27a is cooled by the refrigerant flowing through the secondary side passage 27b and is supercooled. As the third on-off valve 17C, for example, an openable / closable solenoid valve can be used. As the second expansion valve 14B, for example, an electric expansion valve configured to be variable in opening degree by a pulse motor can be used.

  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 and high-temperature gas refrigerant discharged from the compressor 11 to the inlet side of the evaporator 13. is there. The hot gas bypass circuit 22 has a main passage 32, a first branch passage 33 and a second branch passage 34 branched from the main passage 32. One end of each of the first branch passage 33 and the second branch passage 34 is connected to the main passage 32, and the other end is connected to the inlet side of the evaporator 13, that is, between the first expansion valve 14 </ b> A and the evaporator 13. This is a parallel circuit connected to the low-pressure communication pipe 25. The main passage 32 is provided with a fourth on-off valve 17D. As the fourth on-off valve 17D, for example, an openable / closable solenoid valve can be used. The first branch passage 33 is constituted only by a pipe. A drain pan heater 35 is provided in the second branch passage 34. The drain pan heater 35 is provided at the bottom of the drain pan 28 so as to heat the drain pan 28 with a high-temperature refrigerant.

  The refrigeration system 1 is provided with various sensors. In one example, as shown in FIGS. 1 and 2, the refrigeration system 1 includes 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, and a condensation temperature sensor 47. , And an evaporation temperature sensor 48 are provided. Known sensors can be used as the sensors 41 to 48, for example.

  The discharge temperature sensor 41 and the discharge pressure sensor 42 are provided, for example, near 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, for example, near the suction pipe of the compressor 11, that is, near the suction port of the compressor 11 in the low-pressure gas pipe 26. The suction temperature sensor 43 outputs a signal corresponding to the temperature of the suction gas refrigerant drawn into the compressor 11. The suction pressure sensor 44 outputs a signal corresponding to the pressure of the suction gas refrigerant drawn 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 according to the amount of current flowing through the inverter circuit. The rotation sensor 46 is provided in, 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, for example, in the condenser 12 and outputs a signal corresponding to the condensation temperature of the refrigerant flowing in 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 condensing temperature sensor 47 outputs a signal corresponding to the condensing temperature, using the refrigerant temperature in the middle part of the condenser 12 as the condensing temperature. The attachment position of the condensation temperature sensor 47 to the condenser 12 can be arbitrarily changed.

  The evaporation temperature sensor 48 is provided, for example, in the evaporator 13 and outputs a signal corresponding to the evaporation temperature of the refrigerant flowing in 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 evaporating temperature sensor 48 outputs a signal corresponding to the evaporating temperature, using the refrigerant temperature at the intermediate portion of the evaporator 13 as the evaporating temperature. In addition, the attachment position of the evaporation temperature sensor 48 with respect to the evaporator 13 can be arbitrarily changed.

  As shown in FIG. 2, the refrigeration system 1 includes a control device 50 for controlling the operation of the refrigeration system 1 and a notification unit 52. 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 are electrically connected to the control device 50, respectively. Have been. The control device 50 includes a compressor 11, a first expansion valve 14A, a second expansion valve 14B, an external blower 15, an internal blower 16, a first on-off valve 17A, a second on-off valve 17B, and a third on-off valve 17C. , The fourth on-off valve 17D, and the notification unit 52 are electrically connected. The notification unit 52 notifies information about the refrigeration apparatus 1 to the outside of the refrigeration apparatus 1. The notification unit 52 has a display 53 that displays information on the refrigeration apparatus 1, for example. The notification unit 52 may include a speaker instead of or in addition to the display 53. In this case, the notification unit 52 may notify information about the refrigeration apparatus 1 by voice.

  The control device 50 includes a control unit 51. The control unit 51 includes, for example, an arithmetic unit that executes a predetermined control program and a storage unit. The arithmetic processing device includes, for example, a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The storage unit stores various control programs and information used for 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 and 14B, the outside blower 15, the inside blower 16, and the on-off valves 17A to 17D based on the detection results of the sensors 41 to 48. The refrigerating device 1 executes a freezing / cooling operation and a defrost operation by the control unit 51.

[Refrigeration / cooling operation]
In the freezing / cooling operation, the first on-off valve 17A, the second on-off valve 17B, and the third on-off valve 17C are in an open state, and the fourth on-off valve 17D is in a closed state. The opening degrees of the first expansion valve 14A and the second expansion valve 14B are appropriately adjusted. In addition, the compressor 11, the outside fan 15 and the inside fan 16 are operated.

  During the refrigeration / cooling operation, the refrigerant circulates as shown by the solid line arrows in FIG. That is, the high-pressure gas refrigerant compressed by the compressor 11 is condensed by the condenser 12, becomes a liquid refrigerant, and is stored in the receiver 29. The liquid refrigerant stored in the receiver 29 passes through the second opening / closing valve 17B and the dryer 30 and is cooled in the primary side passage 27a of the subcooling heat exchanger 27, and becomes a supercooled liquid refrigerant to become the first expansion valve. Flows to 14A. A part of the liquid refrigerant flowing out of the receiver 29 becomes an intermediate pressure refrigerant via the third opening / closing valve 17C and the second expansion valve 14B as a supercooling source as shown by a broken line arrow in FIG. It flows to the secondary passage 27b of the heat exchanger 27 and cools the liquid refrigerant in the primary passage 27a. The liquid refrigerant supercooled by the supercooling heat exchanger 27 flows to the evaporator 13 after being decompressed by the first expansion valve 14A. In the evaporator 13, the low-pressure liquid refrigerant absorbs heat from the air in the refrigerator and is evaporated and vaporized. Thereby, the inside air is cooled. The low-pressure gas refrigerant evaporated and vaporized by the evaporator 13 is sucked into the compressor 11 and compressed again.

[Defrost operation]
When the freezing / cooling operation is continuously performed, frost adheres to the surface of the heat transfer tube or the like of the evaporator 13, and the frost gradually grows and enlarges. For this reason, the control unit 51 performs a defrost operation, which is an operation for performing defrosting of the evaporator 13.

  The defrost operation is an operation of defrosting the evaporator 13 by bypassing the high-temperature and high-pressure gas refrigerant compressed by the compressor 11 to the inlet side of the evaporator 13, as indicated by a broken arrow in FIG. In the defrost operation, the fourth on-off valve 17D is opened, and the first on-off valve 17A, the second on-off valve 17B, the third on-off valve 17C, and the second expansion valve 14B are fully closed. Then, while the compressor 11 operates, the external fan 15 and the internal fan 16 are stopped.

  After flowing through the main passage 32, the high-pressure and high-temperature gas refrigerant compressed by the compressor 11 passes through the fourth on-off valve 17D and is divided into the first branch passage 33 and the second branch passage. The refrigerant diverted to the second branch passage 34 passes through the drain pan heater 35. The refrigerant flowing out of the drain pan heater 35 merges with the refrigerant that has passed through the first branch passage 33 and flows to the evaporator 13. In the evaporator 13, a high-pressure gas refrigerant (a so-called hot gas) flows inside the heat transfer tube. For this reason, in the evaporator 13, the frost adhering to the heat transfer tubes and the fins is gradually heated by the high-temperature gas refrigerant. As a result, the frost attached to the evaporator 13 is gradually collected in the drain pan 28. The refrigerant used for defrosting the evaporator 13 is sucked into the compressor 11 and is compressed again. Here, inside the drain pan 28, ice blocks and the like that have come off from the surface of the evaporator 13 together with the water in which the frost has melted are collected. The ice blocks and the like are melted by being heated by the refrigerant flowing inside the drain pan heater 35. The molten water is discharged out of the refrigerator through a predetermined flow path.

  Further, as shown in FIG. 2, the control device 50 further includes a refrigerant leakage determination device 60 that determines the presence or absence of refrigerant leakage or that predicts when refrigerant leakage will occur. Here, when the refrigerant leaks, an abnormality of the refrigeration apparatus 1 such as a decrease in the compression efficiency of the compressor 11 due to an insufficient amount of the refrigerant occurs. 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”) to determine the presence or absence of refrigerant leakage, or predicts refrigerant leakage occurrence time. I do.

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 each of the sensors 41 to 48. The data acquisition unit 61 receives time-series data of each of the sensors 41 to 48. In one example, each of the sensors 41 to 48 outputs a detection result for each predetermined time TX to the refrigerant leak determination device 60. One example of the predetermined time TX is one hour. In one example, each of the sensors 41 to 48 stores a detection result detected at a predetermined sampling period over a predetermined time TX, and outputs an averaged detection result at the predetermined time TX to the refrigerant leak determination device 60. Note that each of the sensors 41 to 48 may output a detection result detected at a time determined every predetermined time 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 unit 62 receives data from the data acquisition unit 61. The data storage unit 62 stores the 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 chronological order. The data storage unit 62 of the present embodiment is configured as a recording medium built 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. Note that the data storage unit 62 may be a recording medium provided outside the refrigerant leak determination device 60 or outside the refrigeration device 1. In this case, the data storage unit 62 may include at least one of a USB (Universe Serial Bus) memory, an SD (Secure Digital) memory card, and an HDD (hard disk drive) recording medium.

  The pre-processing unit 63 removes data that becomes noise with respect to the determination of the presence or absence of refrigerant leakage in the time-series data or the prediction of the refrigerant leakage occurrence time, and supplements the section of the removed data with substitute data. The pre-processing unit 63 has a first processing unit 63a and a second processing unit 63b. The data that becomes noise includes, for example, data of instantaneous fluctuations immediately after the compressor 11 is started, data of sections that are not continuous over time, 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 63a. The first processing unit 63a extracts a section for supplementing the substitute data. This section is, 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. including. In the present embodiment, the first processing unit 63a includes a section in which the refrigeration apparatus 1 is stopped, a section immediately after the start of the compressor 11, a section immediately after the stop of the compressor 11, and immediately after the operation of the compressor 11 is switched. Is extracted.

  The second processing unit 63b inputs the substitute data into the section extracted by the first processing unit 63a. This substitute data is a value before or 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 replaces one of the values before and after the section in which the refrigeration apparatus 1 is stopped with substitute data. And Here, the data of the section that is stopped, that is, the section that is not continuous over time is regarded as, for example, “0”. When the first processing unit 63a extracts a section immediately after the start of the compressor 11, the second processing unit 63b sets the value after the section immediately after the start of the compressor 11 as substitute data. The value after the section immediately after the start of the compressor 11 may be an average value of data over a predetermined period after the section immediately after the start of the compressor 11 or may be the average value of the data immediately after the section immediately after the start of the compressor 11. The data may be time data. When the first processing unit 63a extracts the section immediately after the stop of the operation of the compressor 11, the second processing unit 63b sets the value of the section before the section immediately after the stop of the operation of the compressor 11 as substitute data. The value of the section immediately before the section immediately after the stop of the operation of the compressor 11 is the average value of the data in the section immediately before the compressor 11 enters the stop operation as the section before the section immediately after the stop of the compressor 11. Alternatively, the data may be data at a time immediately before the compressor 11 enters the stop operation. When the first processing unit 63a extracts the section immediately after the switching of the operation of the compressor 11, the second processing unit 63b outputs one of the values of the section before and after the section immediately after the switching of the operation of the compressor 11. Is alternative data. One of the values before and after the section immediately after the switching of the operation of the compressor 11 is 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. Alternatively, the data may be data at a predetermined time in 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 the data before and after the section supplemented with the substitute data may be used as the substitute data.

  The refrigerant leak determination unit 64 is electrically connected to the pre-processing unit 63. The refrigerant leak determination unit 64 determines the presence or absence of refrigerant leakage or predicts the refrigerant leakage occurrence time using the data processed by the preprocessing unit 63. The refrigerant leak determination unit 64 has a calculation unit 66 and a determination unit 67.

  The calculation unit 66 calculates a first index value and a second index value in order to calculate the degree of deviation of the refrigerant circuit 20 from the normal state. The normal state of the refrigerant circuit 20 means that, for example, the amount of refrigerant (refrigerant charge) sealed in the refrigerant circuit 20 is within an appropriate range. The calculation unit 66 calculates a first index value from data relating to the operation of the refrigeration apparatus 1 during the first period among the data relating to the operation of the refrigeration apparatus 1. In addition, the calculation unit 66 calculates a second index value from data relating to the operation of the refrigeration apparatus 1 in the second period, which is different in length from the first period, from the data relating to the operation of the refrigeration apparatus 1. Then, the calculating 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 between 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 the presence or absence of refrigerant leakage based on the degree of deviation of the refrigerant circuit 20 from the normal state calculated by the calculation unit 66, or predicts the refrigerant leakage occurrence time. The determination unit 67 outputs the determination result or the prediction result to the output unit 65.

  Here, the presence / absence of refrigerant leakage means that the amount of refrigerant leakage per unit time is not less than a first threshold value, not a small amount of refrigerant leakage. An example of the first threshold is a refrigerant leakage amount that causes an abnormality in the refrigeration apparatus 1 due to refrigerant leakage, and is determined in advance by a test or the like. One example of an abnormality of the refrigeration apparatus 1 is that the temperature of the compressor 11 becomes excessively high due to the fact that the refrigerant charge is less than the lower limit of the appropriate range and the compressor 11 cannot be cooled. In addition, the refrigerant leakage occurrence time may be, for example, a time when the refrigerant charging amount is less than the lower limit value of the appropriate range, or when the refrigerant charging amount is less than the lower limit value of the appropriate range and the compressor 11 cannot be cooled. May be the time when the temperature of the compressor 11 caused by the above becomes equal to or higher than the second threshold value. An example of the second threshold is a temperature at which the possibility of occurrence of an abnormality such as seizure of the compression mechanism of the compressor 11 increases, and is determined in advance by a test 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 the presence or absence of the refrigerant leakage or the prediction result of the refrigerant leakage occurrence time to the data storage unit 62 and the notification unit 52. The notification unit 52 displays, for example, a determination result of the presence or absence of refrigerant leakage or a prediction result of the refrigerant leakage occurrence time by the display 53. The output unit 65 has a wireless communication unit including an antenna. The output unit 65 can communicate with an administrator terminal (administrator terminal 70) via a wireless communication unit. The output unit 65 outputs the determination result of the presence or absence of the refrigerant leakage or the prediction result of the refrigerant leakage occurrence time to the manager terminal 70. The administrator terminal 70 may be a portable communication device such as a smartphone or a tablet computer, or a desktop personal computer.

Next, the details of the determination of the presence or absence of the refrigerant leakage or the prediction of the refrigerant leakage occurrence time performed by the refrigerant leakage determination unit 64 will be described.
The calculation unit 66 uses the data on the operation of the refrigeration apparatus 1 stored in the data storage unit 62 to calculate a first index value by a moving average of the data on the operation of the refrigeration apparatus 1 in the first period, and The second index value is calculated by the moving average of the data on the operation of the refrigeration apparatus 1 in the above. The calculation unit 66 calculates the first index value and the second index value using the data of the first period and the second period before the time when the processing is performed. Then, 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 for the first period is data for one day, and the data for the second period is data for 10 days. In the present embodiment, the sampling cycle is one hour, and data on the operation of the refrigeration apparatus 1 is acquired every hour. Therefore, the data of the first period and the data of the second period can be indicated not only by the length of the period but also by the number of data. One day's data is 24 data, and 10 days' worth of data. Are 240 pieces of 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 indicated by a ratio between a predicted value of the discharge-side refrigerant temperature of the compressor 11 and an actually measured value of the discharge-side refrigerant temperature of the compressor 11. In the present embodiment, the measured value of the discharge-side refrigerant temperature of the compressor 11 with respect 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 measurement value of the discharge-side refrigerant temperature of the compressor 11, and calculates the calculated discharge-side refrigerant temperature of the compressor 11. The discharge-side refrigerant temperature ratio is calculated as the ratio of the measured value of the discharge-side refrigerant temperature of the compressor 11 to the predicted value.

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

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

  The calculation unit 66 calculates an actually measured value of the discharge-side refrigerant temperature of the compressor 11 from a signal from the discharge temperature sensor 41. The measured 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 as, for example, the amount of refrigerant leakage from the refrigerant circuit 20 per unit time increases. Therefore, the degree of divergence of the measured value of the discharge-side refrigerant temperature of the compressor 11 with respect to 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 calculating unit 66 determines the discharge-side refrigerant temperature ratio in the first period (hereinafter, referred to as “first refrigerant temperature ratio”) as the first index value and the discharge-side refrigerant temperature ratio in the second period (hereinafter, “first refrigerant temperature ratio”) as the second index value. 2 refrigerant temperature ratio). As an example, the graph of FIG. 4A shows a transition of each of the first refrigerant temperature ratio and the second refrigerant temperature ratio. As shown in FIG. 4A, before July 9, the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio is small, but after July 9, the degree of deviation gradually increases. You can see that there is.

  The calculation unit 66 calculates, for example, the 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 indicated by the ratio of the first refrigerant temperature ratio to the second refrigerant temperature ratio. As this ratio increases, the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio increases. The difference between the first refrigerant temperature ratio and the second refrigerant temperature ratio may be indicated by the difference between the first refrigerant temperature ratio and the second refrigerant temperature ratio. As the difference increases, the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio increases. As an example, the graph of FIG. 4B shows the transition of the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio. As shown in FIG. 4B, before July 9, the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio is approximately 1.00. It can be seen that after July 9, the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio gradually increases.

  When the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio is equal to or greater than the threshold value XT, the determination unit 67 determines that refrigerant leakage has occurred. The threshold value XT is a value for determining that refrigerant leakage has occurred such that an abnormality occurs in the refrigeration apparatus 1, and is set in advance by a test or the like.

  The determination unit 67 predicts a refrigerant leakage occurrence time based on a change tendency of a degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio. Specifically, the calculation unit 66 calculates the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio, for example, every day, and outputs the calculated degree to the determination unit 67. The determination unit 67 obtains a change tendency of the degree of divergence from the degree of divergence between the first refrigerant temperature ratio and the second refrigerant temperature ratio every day, for example. The determination unit 67 predicts the refrigerant leak occurrence time based on the inclination of the degree of divergence, which is increasing. More specifically, the determination unit 67 predicts when the degree of the difference reaches the threshold XT based on the gradient of the degree of difference between the first refrigerant temperature ratio and the second refrigerant temperature ratio. The determination unit 67 may calculate the gradient of the divergence degree, for example, by regression analysis, or may calculate the divergence degree from a straight line connecting the divergence degrees at two predetermined times. In one example, as illustrated in FIG. 4B, the determination unit 67 determines, based on a change in the degree of divergence between the first refrigerant temperature ratio and the second refrigerant temperature ratio up to July 16, from July 16 onward. The degree of divergence is predicted (broken line portion in FIG. 4B). The determination unit 67 predicts the refrigerant leak occurrence time based on a comparison between the transition of the degree of divergence after July 16 and the threshold value XT.

  With reference to FIG. 5, a specific processing procedure for judging the presence or absence of refrigerant leakage by the refrigerant leakage determination device 60 or predicting the refrigerant leakage occurrence time will be described. This processing is performed, for example, when there is a user request, when the power of the refrigeration apparatus 1 or the refrigerant leak determination apparatus 60 is turned on, when the transportation of the refrigeration apparatus 1 is completed, and before the refrigeration apparatus 1 is used. Executed in at least one case when the check was performed. In the present embodiment, the refrigerant leak determination device 60 is configured to perform the following operations: at the request of the user, when the power of the refrigeration apparatus 1 or the refrigerant leakage determination apparatus 60 is turned on, when the transportation of the refrigeration apparatus 1 is completed, and In each case when the pre-use inspection of the refrigeration apparatus 1 is performed, the determination of the presence or absence of refrigerant leakage or the prediction of the refrigerant leakage occurrence time is executed.

  The refrigerant leak determination device 60 calculates the first refrigerant temperature ratio and the second refrigerant temperature ratio from the data relating to the operation of the refrigerating device 1 in step S11, and proceeds to step S12. The refrigerant leak determination device 60 calculates the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio in step S12, and proceeds to step S13.

  The refrigerant leak determination device 60 determines in step S13 whether the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio is equal to or greater than a threshold value XT. When an affirmative determination is made in step S13, the refrigerant leakage determination device 60 determines that refrigerant leakage has occurred in step S14, and proceeds to step S15. The refrigerant leak determination device 60 communicates the determination result to at least one of the display 53 and the manager terminal 70 in step S15, and ends the process once. The display 53 and the manager terminal 70 complete the transportation of the refrigeration apparatus 1 when the user's request is made in step S15 or when the power of the refrigeration apparatus 1 or the refrigerant leak determination apparatus 60 is turned on. In this case, the determination result of the presence or absence of the refrigerant leakage or the prediction result of the refrigerant leakage occurrence time is notified in at least one case when the pre-use inspection of the refrigeration apparatus 1 is performed. In the present embodiment, the display 53 and the administrator terminal 70 complete the transportation of the refrigeration system 1 when the power of the refrigeration system 1 or the refrigerant leakage determination device 60 is turned on when requested by the user. In this case, the determination result of the presence or absence of the refrigerant leakage or the prediction result of the refrigerant leakage occurrence time is reported in each case when the pre-use inspection of the refrigeration apparatus 1 is performed. In step S15, communication may be made with the notification unit 52 instead of the display 53. When the notification unit 52 has a speaker, the notification unit 52 may report the determination result of the presence or absence of the refrigerant leakage or the prediction result of the refrigerant leakage occurrence time by the speaker.

  When a negative determination is made in step S13, the refrigerant leak determination device 60 calculates a change tendency of the degree of divergence between the first refrigerant temperature ratio and the second refrigerant temperature ratio in step S16, and proceeds to step S17.

  The refrigerant leakage determination device 60 predicts the refrigerant leakage occurrence time based on the gradient of the change in the degree of deviation between the first refrigerant temperature ratio and the second refrigerant temperature ratio in step S17, and proceeds to step S18. The refrigerant leak determination device 60 communicates the prediction result to at least one of the display 53 and the manager terminal 70 in step S18, and ends the process once. As described above, in the flowchart illustrated in FIG. 5, the refrigerant leakage determination device 60 determines the presence or absence of refrigerant leakage, and then predicts the refrigerant leakage occurrence time.

  The refrigerant leakage determination method in the refrigerant leakage determination device 60 described above includes a data storage step, a first calculation step, a second calculation step, and a determination step. This will be described below.

  The data saving step is a step of saving data relating to the operation of the refrigeration apparatus 1. In one example, in the data storage step, the data from the data acquisition unit 61 regarding the operation of the refrigeration apparatus 1 is stored 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 during the first period and calculating a second index value from data relating to the operation of the refrigeration apparatus 1 during the second period. In one example, the first calculation step is executed by the calculation unit 66, and calculates the first index value by a moving average of data on the operation of the refrigeration apparatus 1 during the first period, and calculates the first index value by using the refrigeration apparatus during the second period. A second index value is calculated by a moving average of the data related to the first driving. In one example, the first calculation step includes a preprocessing step of deleting data that becomes noise with respect to the determination of the presence or absence of refrigerant leakage or predicting the refrigerant leakage occurrence time by the preprocessing unit 63 and supplementing the data 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 from the normal state of the refrigerant circuit 20 from the first index value and the second index value. In one example, the second calculation step is executed 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 the presence or absence of refrigerant leakage or predicting the refrigerant leakage occurrence time based on the degree of deviation of the refrigerant circuit 20 from the normal state. In one example, the second index value is set to the normal state of the refrigerant circuit 20, and when the degree of deviation of the first index value from the second index value becomes equal to or greater than a certain threshold value, it is determined that refrigerant leakage has occurred. The determining step predicts when the refrigerant leakage will occur by predicting when the degree of divergence reaches a threshold value based on a change tendency of the degree of divergence of the first index value with respect to the second index value. Describing the relationship between the determination step and FIG. 5, steps S13 to S18 in FIG. 5 correspond to the determination step.

Next, the operation of the present embodiment will be described.
The refrigerant leak determination device 60 calculates a second index value from the data on the operation of the refrigeration apparatus 1 in the second period by a moving average, and uses the calculated second index value as a reference. In the present embodiment, the second period is data relating to the operation of the refrigeration apparatus 1 over a long period of 10 to 30 days, so that the influence of fluctuations in the operation of the refrigeration apparatus 1 in a short period such as one day is reduced.

  In addition, the refrigerant leakage determination device 60 calculates a first index value by a moving average from data on the operation of the refrigeration apparatus 1 during the first period. In the present embodiment, since the first period is data relating to the operation of the refrigeration apparatus 1 in a short period of one day, the influence of recent fluctuations in the operation of the refrigeration apparatus 1 is large.

  In this way, the first index value, which is greatly influenced by the fluctuations related to the operation of the refrigeration apparatus 1, is deviated from the second index value based on the second index value, which is small influenced by the recent fluctuations related to the operation of the refrigeration apparatus 1. By monitoring this, it becomes easy to extract fluctuations related to the operation of the refrigeration apparatus 1. Thereby, when the refrigerant leakage occurs, the first index value remarkably deviates from the second index value, so that the refrigerant leakage determination device 60 can determine that the refrigerant leakage has occurred. Further, the refrigerant leakage determination device 60 can predict the refrigerant leakage occurrence time by acquiring the change tendency of the degree of deviation of the first index value from the second index value and predicting the transition of the degree of deviation.

According to the present embodiment, the following effects can be obtained.
(1) The calculation unit 66 includes, among the data relating to the operation of the refrigeration apparatus 1, a first index value calculated from the data relating to the operation of the refrigeration apparatus 1 during the first period, and a second index value different in length from the first period. A deviation state of the refrigerant circuit 20 from a normal state is calculated based on the second index value calculated from data on the operation of the refrigeration apparatus 1 during the period. The determination unit 67 determines the presence or absence of refrigerant leakage based on the degree of deviation of the refrigerant circuit 20 from the normal state, or predicts the refrigerant leakage occurrence time. According to this configuration, the first index value calculated using the data relating to the normal operation such as the cooling operation and the defrosting operation of the refrigeration apparatus 1 and the operation of the refrigeration apparatus 1 including the operation of the pre-use inspection of the refrigeration apparatus 1 and The deviation state of the refrigerant circuit 20 from the normal state can be calculated based on the deviation state from the second index value. Accordingly, it is possible to determine the presence or absence of refrigerant leakage or to predict the refrigerant leakage occurrence time based on the state of the refrigerant circuit 20 deviating from the normal state. As described above, it is possible to determine the presence or absence of refrigerant leakage or to predict the timing of occurrence of refrigerant leakage without executing a special operation for determining the presence or absence of refrigerant leakage.

  (2) The second index value calculated from the long second period has little effect on the fluctuation of the operation of the refrigeration apparatus 1, and the first index value calculated from the short first period is the refrigeration apparatus 1 The influence on the fluctuation of the driving of the vehicle increases. Therefore, 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 between the first index value and the second index value. This makes it easy to extract the fluctuations in the operation of the refrigeration apparatus 1, and it is possible to determine the presence or absence of refrigerant leakage or predict the refrigerant leakage occurrence time based on the fluctuations in the operation of the refrigeration apparatus 1.

  (3) The first index value is calculated by a moving average of data on the operation of the refrigeration apparatus 1 during the first period, and the second index value is calculated by a moving average of data on the operation of the refrigeration apparatus 1 during the second period. You. According to this configuration, determination of the presence or absence of refrigerant leakage or prediction of refrigerant leakage occurrence time is performed based on the degree of deviation between the long-term fluctuation of the operation of the refrigeration apparatus 1 and the short-term fluctuation of the operation of the refrigeration apparatus 1. It can be performed.

  (4) When the amount of refrigerant (refrigerant charging amount) sealed in the refrigerant circuit 20 is smaller than an appropriate range, the suction pressure of the compressor 11 decreases, resulting in insufficient cooling by the refrigerant inside the compressor 11, There is a possibility that the temperature of the compressor 11 becomes excessively high. That is, the discharge-side refrigerant temperature of the compressor 11 when the amount of refrigerant sealed in the refrigerant circuit 20 is less than the lower limit value of the appropriate range is the same as that of the compressor 11 when the amount of refrigerant sealed in the refrigerant circuit 20 is within the appropriate range. It becomes higher than the discharge side refrigerant temperature. Therefore, in the present embodiment, a discharge-side refrigerant temperature ratio that is an actually measured value of the discharge-side refrigerant temperature with respect to a predicted value of the discharge-side refrigerant temperature of the compressor 11 is used as the first index value and the second index value. For this reason, it is possible to accurately determine the presence or absence of refrigerant leakage, or to accurately predict the timing of occurrence of refrigerant leakage.

  (5) The calculating unit 66 calculates a predicted refrigerant temperature for each power supply frequency and power supply voltage, and calculates a first refrigerant temperature ratio and a second refrigerant temperature ratio for each power supply frequency and power supply voltage. Accordingly, the first refrigerant temperature ratio and the second refrigerant temperature ratio can be calculated with higher accuracy, so that it is possible to accurately determine the presence or absence of refrigerant leakage or to accurately predict the refrigerant leakage occurrence time.

  (6) Reducing refrigerant leakage by omitting data relating to the operation of the refrigeration apparatus 1 which becomes noise when the presence or absence of refrigerant leakage is determined by the pre-processing unit 63 or predicting the refrigerant leakage occurrence time, and supplementing with substitute data. It is possible to accurately determine the presence or absence of refrigerant, or predict the refrigerant leakage occurrence time.

  (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 after the section immediately after the start of the compressor 11 as substitute data. When the first processing unit 63a extracts the section immediately after the stop of the operation of the compressor 11, the second processing unit 63b sets the value of the section before the section immediately after the stop of the operation of the compressor 11 as substitute data. When the first processing unit 63a extracts the section immediately after the switching of the operation of the compressor 11, the second processing unit 63b outputs one of the values of the section before and after the section immediately after the switching of the operation of the compressor 11. Is alternative data. According to this configuration, by using data that is temporally closer to the section extracted by the first processing unit 63a as the substitute data, the degree of discrepancy between the data regarding the actual operation of the refrigeration apparatus 1 and the substitute data can be reduced. Therefore, the determination of the presence or absence of refrigerant leakage or the prediction of refrigerant leakage occurrence time can be accurately performed.

  (8) Since the occurrence of refrigerant leakage or the timing of refrigerant leakage occurrence is displayed on the display 53 of the refrigeration system 1 or the manager terminal 70 by the notification unit 52, the manager or the worker of the refrigeration system 1 can check for refrigerant leakage. It is possible to grasp the generation time or the refrigerant leakage generation time.

(Example of change)
The description of the above embodiment is an example of a form that a refrigerant leak determination device according to the present disclosure, a refrigeration apparatus including the refrigerant leak determination device, and a refrigerant leak determination method can take, and is not intended to limit the form. . A refrigerant leak determination device according to the present disclosure, a refrigeration device including the refrigerant leakage determination device, and a refrigerant leakage determination method are, for example, a combination of the following modifications of the above-described embodiment, and at least two modifications that do not contradict each other. Can take the form. In the following modified examples, portions common to the above-described embodiment will be denoted by the same reference numerals as those in the above-described embodiment, and description thereof will be omitted.

  In the above embodiment, the degree of deviation between the first index value and the second index value is indicated by the ratio of the first index value to the second index value, but is not limited to this. The method of calculating the degree of deviation between the first index value and the second index value can be arbitrarily changed. In one example, the calculation unit 66 calculates the degree of deviation between the first index value and the second index value as a standard deviation using the first index value and the second index value, skewness, likelihood, kurtosis, and average value. May be calculated based on at least one of the following.

  In the above embodiment, the refrigerant leakage determination device 60 performs both the determination of the presence or absence of the refrigerant leakage and the prediction of the refrigerant leakage occurrence time, but is not limited thereto. The refrigerant leakage determination device 60 may execute only the determination of the presence or absence of the refrigerant leakage. Further, the refrigerant leakage determination device 60 may execute the prediction of the refrigerant leakage occurrence time when the degree of deviation between the first index value and the second index value is smaller than the threshold value XT. In this case, the refrigerant leakage determination device 60 can omit the determination of the presence or absence of the refrigerant leakage.

  In the above-described embodiment, the preprocessing unit 63 determines whether there is a refrigerant leak in the time-series data, or removes data that becomes noise with respect to predicting a refrigerant leak occurrence time, and substitutes a section of the removed data. The data was supplemented, but not limited to this. The pre-processing unit 63 may simply remove data that becomes noise with respect to determining the presence or absence of refrigerant leakage in the time-series data or predicting the refrigerant leakage occurrence time. According to this configuration, it is possible to accurately determine the presence or absence of refrigerant leakage or to accurately predict the refrigerant leakage occurrence time.

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

  In the above embodiment, instead of the discharge-side refrigerant temperature ratio as the first index value and the second index value, the actual measured value of the refrigerant pressure on the discharge side of the compressor 11 with respect to the predicted value of the refrigerant pressure on the discharge side of the compressor 11 May be used as the discharge side refrigerant pressure ratio. The calculation unit 66 determines the discharge-side refrigerant pressure ratio in the first period (hereinafter, referred to as “first refrigerant pressure ratio”) as the first index value and the discharge-side refrigerant pressure ratio in the second period (hereinafter, “first refrigerant pressure ratio”) as the second index value. 2 refrigerant pressure ratio). Then, the calculation unit 66 calculates the degree of deviation between the first refrigerant pressure ratio and the second refrigerant pressure ratio. 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, the determination unit 67 determines that refrigerant leakage has occurred. In addition, the determination unit 67 predicts a refrigerant leakage occurrence time based on a change tendency of a degree of deviation between the first refrigerant pressure ratio and the second refrigerant pressure ratio. Further, instead of the discharge-side cooling temperature ratio, the ratio of the measured value of the superheat degree of the suction gas refrigerant to the predicted value of the superheat degree of the suction gas refrigerant drawn into the compressor 11 may be used. The ratio of the measured value of the degree of supercooling of the liquid refrigerant at the outlet of the condenser 12 to the predicted value of the degree of subcooling of the liquid refrigerant at the outlet may be used.

  In the above modification, the first index value and the second index value are obtained from the predicted value of the refrigerant pressure on the discharge side of the compressor 11 or the actually measured value of the refrigerant pressure on the discharge side of the compressor 11 instead of the discharge-side refrigerant pressure ratio. May be calculated. In one example, the calculation unit 66 calculates the first index value by a moving average of the predicted value of the refrigerant pressure on the discharge side of the compressor 11 during the first period, and calculates the first index value based on the moving average of the refrigerant pressure on the discharge side of the compressor 11 during the second period. A second index value is calculated by a moving average of the predicted values. Further, in one example, the calculation unit 66 calculates the first index value by a moving average of the actually measured value of the refrigerant pressure on the discharge side of the compressor 11 in the first period, and calculates the refrigerant pressure on the discharge side of the compressor 11 in the second period. The second index value is calculated based on the moving average of the actual measurement values.

  In the above embodiment, the data storage unit 62 may be a server external to the refrigeration apparatus 1 communicably connected to the refrigeration apparatus 1. One example of this server includes a cloud server. That is, the refrigerant leak determination device 60 stores the data on the server by transmitting the data acquired by the data acquisition unit 61 to the server.

In the above embodiment, the refrigerant leakage determination device 60 and the notification unit 52 are provided separately, but the invention is not limited thereto, and the refrigerant leakage determination device 60 may include the notification unit 52.
In the above 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 may be applied to a refrigerator for a fixed warehouse. When the refrigerating device 1 is applied to a refrigerating device other than the transport refrigerating device, the power of the refrigerating device 1 or the refrigerant leak determining device 60 is turned on when a user requests it. In at least one case when the pre-use check of the refrigeration apparatus 1 is performed, the presence or absence of refrigerant leakage is determined, or the refrigerant leakage occurrence time is predicted. In addition, the notification unit 52 performs at least one of when the user requests, when the power of the refrigeration apparatus 1 or the refrigerant leakage determination apparatus 60 is turned on, and when the pre-use inspection of the refrigeration apparatus 1 is performed. In this case, the result of the determination of the presence or absence of the refrigerant leakage or the result of the prediction of the refrigerant leakage occurrence time is reported.

  -In above-mentioned embodiment, although the structure of the refrigeration apparatus 1 for containers was demonstrated, the structure of the refrigeration apparatus is not limited to this. For example, as shown in FIG. 6, a refrigeration apparatus may be used as the air conditioner 80. The air conditioner 80 includes a refrigerant circuit 90 formed by connecting an outdoor unit 80A installed outdoors and a wall-mounted indoor unit 80B mounted on an indoor wall or the like by a refrigerant pipe 91.

  The outdoor unit 80A includes a compressor 81, a four-way switching valve 82, an outdoor heat exchanger 83, an expansion valve 84, an outdoor fan 85, an outdoor control device 86, and the like, whose capacity is changed by changing the operation frequency. The compressor 81 is, for example, a swinging 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. For example, a fin-and-tube heat exchanger can be used. The expansion valve 84 is, for example, an electronic expansion valve. The outdoor fan 85 has a motor whose rotation speed can be changed as a drive source, and an impeller connected to an output shaft of the motor. One example of an impeller is a propeller fan. The outdoor fan 85 generates an airflow of outdoor air passing through the outdoor heat exchanger 83 by rotating an impeller by a motor. The outdoor control device 86 is electrically connected to the motor of the compressor 81, the four-way switching valve 82, the expansion valve 84, and the motor of the outdoor fan 85, and controls these operations.

  The indoor unit 80B includes an indoor heat exchanger 87, an indoor fan 88, an indoor control device 89, and the like. The indoor heat exchanger 87 exchanges heat between the indoor air and the refrigerant, and for example, a fin-and-tube heat exchanger can be used. The indoor fan 88 has a motor whose rotation speed can be changed as a drive source, and an impeller connected to an output shaft of the motor. One example of an 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 by connecting the compressor 81, the four-way switching valve 82, the outdoor heat exchanger 83, and the expansion valve 84, the indoor heat exchanger 87, and the accumulator 81a in an annular manner by a refrigerant pipe 91. By switching the four-way switching valve 82, a vapor compression refrigeration cycle in which the refrigerant is reversibly circulated can be executed.

  That is, when the four-way switching valve 82 is switched to the cooling mode connection state (the state shown by the solid line), the refrigerant circuit 90 includes the compressor 81, the four-way switching valve 82, the outdoor heat exchanger 83, the expansion valve 84, and the indoor. A cooling cycle in which the refrigerant circulates in the order of the heat exchanger 87, the four-way switching valve 82, the accumulator 81a, and the compressor 81 is formed. Thus, in the air conditioner 80, a cooling operation in which the outdoor heat exchanger 83 functions as a condenser and the indoor heat exchanger 87 functions as an evaporator is performed. When the four-way switching valve 82 is switched to the heating mode connection state (the state shown by the broken line), the refrigerant circuit 90 includes the accumulator 81a, the compressor 81, the four-way switching valve 82, the indoor heat exchanger 87, and the expansion valve. A heating cycle in which the refrigerant circulates in the order of 84, the outdoor heat exchanger 83, the four-way switching valve 82, and the compressor 81 is formed. Thus, in the air conditioner 80, a heating operation in which the indoor heat exchanger 87 functions as a condenser and the outdoor heat exchanger 83 functions as an evaporator is performed.

  In the air conditioner 80, for example, the refrigerant leak determination device 60 (not shown in FIG. 6) is provided in one of the outdoor control device 86 and the indoor control device 89. The notification unit 52 (not shown in FIG. 6) is provided, for example, on 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 refrigerant leak determination device 60 may be omitted from the refrigerating device 1. The refrigerant leak determination device 60 may be provided separately from the refrigeration device 1. In one example, the refrigerant leak determination device 60 may be provided in a server that can communicate with the refrigeration device 1. In this case, the refrigeration apparatus 1 obtains a determination result of the presence or absence of the refrigerant leakage or a prediction result of the refrigerant leakage occurrence time by communicating with the refrigerant leakage determination apparatus 60.

  Although the embodiment of the present apparatus has been described above, it is understood that various changes in form and details can be made without departing from the spirit and scope of the present apparatus described in the claims. Would.

1. Refrigeration equipment (refrigeration equipment for transportation)
11 compressor 12 condenser 13 evaporator 14A first expansion valve (pressure reducing device)
14B: second expansion valve (pressure reducing device)
20 refrigerant circuit 52 notification unit 60 refrigerant leakage determination device 66 calculation unit 67 determination unit

Claims (15)

A refrigerating apparatus (1) including a compressor (11), a condenser (12), a pressure reducing device (14A, 14B), and an evaporator (13), and including a refrigerant circuit (20) configured to circulate a refrigerant. A) a refrigerant leakage determination device (60) for determining refrigerant leakage,
A calculating unit (66) for calculating a degree of deviation of the refrigerant circuit (20) from a normal state based on data relating to the operation of the refrigeration system (1); and a refrigerant leak based on a calculation result of the calculating unit (66). And a determining unit (67) for determining the presence or absence of the refrigerant, or predicting the refrigerant leakage occurrence time,
The calculation unit (66) includes a first index value calculated from data relating to the operation of the refrigeration apparatus (1) in a first period, among the data relating to the operation of the refrigeration apparatus (1); Calculates a degree of deviation from a normal state of the refrigerant circuit (20) based on a second index value calculated from data on the operation of the refrigeration apparatus (1) in a second period having a different length,
The refrigerant leak judging device judges the presence or absence of the refrigerant leak based on the degree of deviation of the refrigerant circuit (20) from a normal state, or predicts the refrigerant leak occurrence time. The refrigerant leak according to claim 1, wherein the calculation unit (66) detects a degree of deviation from a normal state of the refrigerant circuit (20) based on a degree of deviation between the first index value and the second index value. Judgment device. Data relating to the operation of the refrigeration system (1) during the first period is data for one day,
The refrigerant leak determination device according to claim 1 or 2, wherein data relating to the operation of the refrigeration apparatus (1) during the second period is data for 10 days or more and 30 days or less. Data relating to the operation of the refrigeration apparatus (1) in the first period is 24 data,
4. The refrigerant leakage determination device according to claim 3, wherein data relating to the operation of the refrigeration device (1) during the second period is data of 240 or more and 720 or less. 5. The first index value is calculated by a moving average of data on the operation of the refrigeration system (1) during the first period,
The refrigerant leak determination device according to any one of claims 1 to 4, wherein the second index value is calculated by a moving average of data regarding operation of the refrigeration device (1) during the second period. The first index value and the second index value are respectively a predicted value of the discharge-side refrigerant temperature of the compressor (11), an actually measured value of the discharge-side refrigerant temperature of the compressor (11), and the compressor (11). 6) any one of the discharge-side refrigerant temperature indices calculated based on the predicted value of the discharge-side refrigerant temperature and the actually measured value of the discharge-side refrigerant temperature of the compressor (11). Item 8. The refrigerant leakage determination device according to Item 1. The predicted value of the discharge-side refrigerant temperature of the compressor (11) includes a condensing temperature and an evaporating temperature when the refrigerant charging amount in the refrigerant circuit (20) is within an appropriate range, and an expansion valve (14A) serving as the pressure reducing device. , 14B), power supply to the refrigeration system (1) by regression analysis using at least one of the opening degree of the compressor (11), the operating frequency of the compressor (11), and the rotation speed of the compressor (11) as variables. The refrigerant leakage determination device according to claim 5, wherein the calculation is performed for each of a power supply frequency and a power supply voltage of a power supply serving as a power supply. The calculating unit (66) includes data of a section in which the refrigerating apparatus (1) is stopped, data of a section immediately after the compressor (11) is started, and data of a section immediately after the compressor (11) is stopped. And calculating the first index value and the second index value except for at least one of data in a section immediately after the switching of the operation of the compressor (11). The refrigerant leakage determination device according to claim 1. The calculating unit (66) includes data of a section in which the refrigerating apparatus (1) is stopped, data of a section immediately after the compressor (11) is started, and data of a section immediately after the compressor (11) is stopped. And calculating the first index value and the second index value by using substitute data for at least one of data in a section immediately after the switching of the operation of the compressor (11). The refrigerant leakage determination device according to claim 1. The substitute data includes a section in which the refrigerating apparatus (1) is stopped, a section immediately after the start of the compressor (11), a section immediately after the stop of the compressor (11), and a section of the compressor (11). The refrigerant leak determination device according to claim 9, wherein the refrigerant leakage determination device is a value before or after a section using the substitute data in a section immediately after the switching of operation or a representative value determined in advance. The calculation unit (66) calculates a degree of deviation between the first index value and the second index value as a standard deviation, a skewness, a likelihood, a kurtosis using the first index value and the second index value. The refrigerant leakage determination device according to any one of claims 1 to 10, wherein the calculation is performed based on at least one of: an average value; A notification unit (52) for notifying the determination result of the presence or absence of the refrigerant leakage or the prediction result of the refrigerant leakage occurrence time,
The notification unit (52) is provided when a user's request is made, when the power of the refrigeration apparatus (1) or the refrigerant leak determination apparatus (60) is turned on, and when the refrigeration apparatus (1) is used. The refrigerant leakage according to any one of claims 1 to 11, wherein at least one case when the pre-inspection has been performed, the determination result of the presence or absence of the refrigerant leakage or the prediction result of the refrigerant leakage occurrence time is reported. Judgment device.   A refrigeration system comprising the refrigerant leakage determination device (60) according to any one of claims 1 to 12. The refrigeration apparatus includes a transportation refrigeration apparatus (1),
The transport refrigeration 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 refrigerant leakage occurrence time,
The notification unit (52) is configured to, when requested by a user, turn on the power of the transport refrigeration system (1) or the refrigerant leakage determination device (60), ) Is completed, and at least one of the cases where a pre-use check of the transport refrigeration apparatus (1) is performed, the determination result of the presence or absence of the refrigerant leakage or the prediction of the refrigerant leakage occurrence time The refrigeration apparatus according to claim 13, which reports a result. A refrigerating apparatus (1) including a compressor (11), a condenser (12), a pressure reducing device (14A, 14B), and an evaporator (13), and including a refrigerant circuit (20) configured to circulate a refrigerant. )) A refrigerant leak determination method according to
A data storage step of storing data relating to the operation of the refrigeration system (1);
A first index value is calculated from data on the operation of the refrigeration apparatus (1) in a first period, and a second index value is calculated from data on the operation of the refrigeration apparatus (1) in a second period having a length different from the first period. A first calculation step of calculating an index value;
A second calculation step of calculating a degree of deviation from a normal state of the refrigerant circuit (20) based on the first index value and the second index value calculated in the first calculation step;
A judging step of judging the presence or absence of refrigerant leakage or predicting the refrigerant leakage occurrence time based on the degree of deviation of the refrigerant circuit (20) from a normal state;
A refrigerant leakage determination method comprising: