Refrigerant leak detection system, method, and program

Abstract

To determine leakage of two kinds of refrigerants.SOLUTION: A refrigerant leakage detection system comprises a control unit. The control unit acquires operating data of a refrigeration air-conditioning apparatus, determines first refrigerant leakage from the operating data, and determines second refrigerant leakage from the operating data, where the data for determining the first refrigerant leakage is operating data acquired at intervals equal to or less than a first threshold, and the data for determining the second refrigerant leakage is operating data equal to or larger than a second threshold.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present disclosure relates to a refrigerant leak detection system, method, and program. [Background technology]

[0002] Conventionally, a technique for detecting refrigerant leakage from air conditioners has been known (Patent Document 1). Recently, refrigerant leakage detection systems have become widespread, which acquire operating data of air conditioners using a remote monitoring function and detect a decrease in the amount of refrigerant retained from the acquired operating data and calculation data using the operating data. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-249435 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, refrigerant leak detection systems must not only detect rapid leaks, in which a large amount of refrigerant leaks in a short period of time, causing oxygen deficiency or ignition of flammable refrigerant, but also slow leaks, in which refrigerant leaks gradually over the long term, resulting in a decrease in performance.

[0005] The present disclosure aims to determine two types of refrigerant leaks.

[0006] A refrigerant leak detection system according to a first aspect of the present disclosure includes: A refrigerant leakage detection system including a control unit, The control unit is Acquire operating data for refrigeration and air conditioning equipment, determining a first refrigerant leak from the operating data; determining a second refrigerant leak from the operating data; The data for determining whether or not there is a first refrigerant leak is operating data acquired at intervals equal to or less than a first threshold value; The data for determining whether or not a second refrigerant leak has occurred is the operating data equal to or greater than a second threshold value.

[0007] According to the first aspect of the present disclosure, two types of refrigerant leaks can be determined. Specifically, the first refrigerant leak is a rapid leak that is easier to determine from operating data acquired at short intervals, and the second refrigerant leak is a slow leak that is easier to determine from operating data acquired over a long period of time, making it possible to detect two types of refrigerant leaks with different characteristics.

[0008] A refrigerant leak detection system according to a second aspect of the present disclosure is the refrigerant leak detection system according to the first aspect, The first threshold is 5 minutes and the second threshold is 1 week.

[0009] According to the second aspect of the present disclosure, by using operation data acquired at intervals of 5 minutes or less for judgment, even if a rapid leak occurs, it can be detected immediately and oxygen deficiency and fire accidents can be prevented. In addition, by using trend changes of long-term operation data of one week or more for judgment, it is possible to reliably detect slow leaks, which are difficult to detect changes due to leakage using only short-term operation data.

[0010] A refrigerant leak detection system according to a third aspect of the present disclosure is the refrigerant leak detection system according to the first or second aspect, The data for determining whether or not a second refrigerant leak has occurred is the operating data equal to or greater than the second threshold value and processed data obtained by processing the operating data equal to or greater than the second threshold value.

[0011] According to the third aspect of the present disclosure, the second refrigerant leakage can be determined not only from the operation data but also from data processed from the operation data. Specifically, for example, slow leaks can be more easily detected by using long-term operation data and processed data obtained by calculating specific data among the operation data. An example of such processed data is subcooling (SC), which is the difference between the condensation temperature and the condenser outlet temperature and has a high correlation with the amount of refrigerant leakage.

[0012] A refrigerant leak detection system according to a fourth aspect of the present disclosure is a refrigerant leak detection system according to any one of the first to third aspects, The control unit is When the first refrigerant leakage is detected, an operating state of the refrigeration and air conditioning equipment or an external equipment linked to the refrigeration and air conditioning equipment is changed; When the second refrigerant leakage is detected, the operating state of the refrigeration and air conditioning equipment or the external equipment is not changed.

[0013] According to the fourth aspect of the present disclosure, in the case of a refrigerant leak determined from operating data acquired at short intervals, there is a high risk of oxygen deficiency, fire, or breakdown of the refrigeration and air conditioning equipment due to a rapid leak, and the urgency is high. Therefore, the operating state of the refrigeration and air conditioning equipment or external equipment is changed, and measures such as stopping the operation of the equipment or ventilating the room to exhaust a large amount of refrigerant that has leaked into the closed space are taken to prevent the occurrence of an accident. In the case of a refrigerant leak determined from operating data acquired over a long period of time, the urgency is low, and the operating state of the refrigeration and air conditioning equipment or external equipment is not changed.

[0014] A refrigerant leak detection system according to a fifth aspect of the present disclosure is a refrigerant leak detection system according to any one of the first to fourth aspects, The first refrigerant leak has a refrigerant leakage rate equal to or greater than a third threshold, and the second refrigerant leak has a refrigerant leakage rate less than the third threshold.

[0015] According to a fifth aspect of the present disclosure, by setting a third threshold value related to the leakage rate, it becomes possible to set the first threshold value and the second threshold value according to the characteristics of the refrigeration and air conditioning equipment, thereby making it possible to reliably determine whether the refrigerant is leaking rapidly or slowly.

[0016] A refrigerant leak detection system according to a sixth aspect of the present disclosure is a refrigerant leak detection system according to any one of the first to fifth aspects, The operating data, physical phenomenon to be detected, judgment logic, and judgment threshold used by the control unit to determine the first refrigerant leak are different from the operating data, physical phenomenon to be detected, judgment logic, and judgment threshold used by the control unit to determine the second refrigerant leak.

[0017] According to the sixth aspect of the present disclosure, it is possible to realize a determination method suitable for detecting a rapid leak and a slow leak depending on the characteristics of each type of leak, thereby making it possible to determine and detect refrigerant leaks of two different characteristics.

[0018] A refrigerant leak detection system according to a seventh aspect of the present disclosure is the refrigerant leak detection system according to the sixth aspect, The control unit that determines whether or not there is a first refrigerant leak uses the amount of change or rate of change in operational data related to the temperature and pressure of the refrigeration and air conditioning equipment, and sensor data for detecting leaked gas.

[0019] According to the seventh aspect of the present disclosure, a first refrigerant leak can be determined from operating data related to the temperature and pressure of the refrigeration and air conditioning equipment, which change rapidly due to a rapid leak, and from sensor data detecting the leaking gas.

[0020] A refrigerant leak detection system according to an eighth aspect of the present disclosure is a refrigerant leak detection system according to any one of the first to seventh aspects, The refrigerant leak detection system includes the refrigeration and air conditioning equipment and a server, The control unit is installed in any one of the refrigeration and air conditioning equipment, an external controller of the refrigeration and air conditioning equipment, or the server.

[0021] According to the eighth aspect of the present disclosure, the locations for installing the control unit that determines whether there is a first refrigerant leak and the control unit that determines whether there is a second refrigerant leak can be arbitrarily selected depending on the installation conditions of the refrigeration and air conditioning equipment.

[0022] A refrigerant leak detection system according to a ninth aspect of the present disclosure is a refrigerant leak detection system according to any one of the first to seventh aspects, The refrigerant leak detection system includes the refrigeration and air conditioning equipment and a server, A control unit that determines whether or not there is a first refrigerant leak and a control unit that determines whether or not there is a second refrigerant leak are installed in a distributed manner in the refrigeration and air conditioning equipment, an external controller of the refrigeration and air conditioning equipment, and the server.

[0023] According to the ninth aspect of the present disclosure, the control unit can be installed in a location suitable for determining a first refrigerant leak and in a location suitable for determining a second refrigerant leak.

[0024] A refrigerant leak detection system according to a tenth aspect of the present disclosure is the refrigerant leak detection system according to the ninth aspect, The control unit that determines whether the first refrigerant leaks is installed in the refrigeration and air conditioning equipment or an external controller of the refrigeration and air conditioning equipment, A control unit that determines whether or not there is a second refrigerant leak is installed in the server.

[0025] According to the tenth aspect of the present disclosure, since operating data acquired at short intervals is processed by the refrigeration and air conditioning equipment or an external controller, there is no need to send large amounts of data to the server, and the server can concentrate on processing operating data acquired over a long period of time, thereby reducing equipment costs and communication costs.

[0026] A refrigerant leak detection system according to an eleventh aspect of the present disclosure is the refrigerant leak detection system according to the ninth aspect, The control unit that determines whether the first refrigerant leaks is present is installed in an external controller of the refrigeration and air conditioning equipment, a control unit that determines whether the second refrigerant is leaking is installed in the server; The external controller processes the driving data and transmits the processed driving data to the server.

[0027] According to the eleventh aspect of the present disclosure, the driving data acquired at short intervals is processed by the external controller, so that it is not necessary to transmit the data to the server, and the server can process the driving data acquired over a long period of time. Furthermore, the external controller processes the driving data before transmitting it to the server, so that the amount of communication data can be reduced, and the amount of calculations at the server can be reduced because data processing at the server is no longer necessary, so that the operating costs of the system can be reduced.

[0028] A refrigerant leak detection system according to a twelfth aspect of the present disclosure is the refrigerant leak detection system according to the eleventh aspect, The processing involves thinning out the operation data.

[0029] According to the twelfth aspect of the present disclosure, the amount of data to be transmitted to the server for use in the second coolant leakage determination can be reduced.

[0030] A refrigerant leak detection system according to a thirteenth aspect of the present disclosure is the refrigerant leak detection system according to the eleventh aspect, The processing involves calculating the operating data to create new data.

[0031] According to the thirteenth aspect of the present disclosure, by creating processed data such as subcooling (SC) from operating data in advance by an external controller, it is possible to reduce the amount of data transmitted to the server and the amount of calculations in the server.

[0032] A refrigerant leak detection system according to a fourteenth aspect of the present disclosure is a refrigerant leak detection system according to any one of the first to thirteenth aspects, The result of the first coolant leakage determination and the result of the second coolant leakage determination are stored in a storage device.

[0033] According to the fourteenth aspect of the present disclosure, it is possible to keep information on whether or not a first refrigerant leak has been detected and information on whether or not a second refrigerant leak has been detected.

[0034] A method according to a fifteenth aspect of the present disclosure, comprising: A method executed by a control unit of a refrigerant leak detection system, comprising: Acquiring operation data of the refrigeration and air conditioning equipment; determining a first refrigerant leak from the operating data; determining a second refrigerant leak from the operating data; The data for determining whether or not there is a first refrigerant leak is operating data acquired at intervals equal to or less than a first threshold value; The data for determining whether or not a second refrigerant leak has occurred is the operating data equal to or greater than a second threshold value.

[0035] A program according to a sixteenth aspect of the present disclosure, Refrigerant leak detection system, Procedures for acquiring operating data of refrigeration and air conditioning equipment; determining a first refrigerant leak from the operating data; and determining whether a second refrigerant leak occurs based on the operating data. The data for determining whether or not there is a first refrigerant leak is operating data acquired at intervals equal to or less than a first threshold value; The data for determining whether or not a second refrigerant leak has occurred is the operating data equal to or greater than a second threshold value. [Brief description of the drawings]

[0036] [Figure 1] FIG. 1 is an overall configuration diagram of the present disclosure. [Diagram 2] 1 shows examples of the overall configuration of the present disclosure (<Example 1> and <Example 2>). [Diagram 3] 1 shows examples of the overall configuration of the present disclosure (<Example 3>, <Example 4>, <Example 5>). [Figure 4]FIG. 1 is a hardware configuration diagram of an air conditioning system (in cooling operation) according to an embodiment of the present disclosure. [Diagram 5] FIG. 2 is a hardware configuration diagram of an air conditioning system (in heating operation) according to an embodiment of the present disclosure. [Figure 6] FIG. 1 is a hardware configuration diagram of an air conditioning system (in the case of simultaneous cooling and heating operation) according to an embodiment of the present disclosure. [Figure 7] The case where an economizer circuit according to an embodiment of the present disclosure is provided is an example in which at least one of the heat source side and the utilization side is a water-cooled type. [Figure 8] 13 is an example of a case having an intermediate injection circuit according to an embodiment of the present disclosure. [Figure 9] FIG. 2 is a hardware configuration diagram of an external controller and a server according to an embodiment of the present disclosure. [Figure 10] FIG. 2 is a functional block diagram of a control unit according to an embodiment of the present disclosure. [Figure 11] 4 is a flowchart of a refrigerant leakage detection process according to an embodiment of the present disclosure. [Figure 12] FIG. 11 is a diagram showing the relationship between the refrigerant leakage rate and the total charge leakage time when a rapid leakage occurs in a building multi-air conditioner having an average refrigerant charge (20 kg) according to one embodiment of the present disclosure. [Figure 13] FIG. 11 is a diagram showing the daily SC (representative value) over the course of a year of a building multi-air conditioner in which a slow leak has occurred according to an embodiment of the present disclosure, and the daily predicted SC (representative value) under normal conditions predicted from other operating data for that year. [Figure 14] 1A and 1B are diagrams illustrating a refrigerant amount index value ΔSC defined as the difference between standard SC and predicted SC according to an embodiment of the present disclosure, and a 7-day moving average and a 14-day moving average of ΔSC. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0038] <Overall composition> 1 is an overall configuration diagram of the present disclosure. The refrigerant leakage detection system 1 can include a refrigeration and air conditioning device 20, an external controller 30, a server 40, an external device 50, and a storage device 60. Each of these will be described below.

[0039] The refrigeration and air conditioning equipment 20 is a refrigerator or ice maker used in the refrigeration and freezing fields, a showcase installed in a supermarket or the like, a refrigerated warehouse, a refrigerated container, or the like.

[0040] The external controller 30 is installed in the same building or the like as the refrigeration and air conditioning equipment 20, and is a control device that manages the operating state and operating schedule of one or more refrigeration and air conditioning equipment.

[0041] The server 40 is a server installed at a location away from the refrigeration and air conditioning equipment 20 and the external controller 30 (for example, a server on the cloud).

[0042] The external device 50 is a device that operates in conjunction with the refrigeration and air conditioning device 20. For example, the external device 50 is a ventilation fan, a refrigerant piping shutoff valve, a siren, an alarm device, or the like.

[0043] The storage device 60 is a storage device installed in a location away from the refrigeration and air conditioning equipment 20 and the external controller 30 (for example, a storage device on the cloud).

[0044] The control unit (processor) 10 determines whether there is a first refrigerant leak or a second refrigerant leak.

[0045] The control unit 10 determines whether a first refrigerant leak has occurred from the operation data of the refrigeration and air conditioning equipment 20. The data for determining whether a first refrigerant leak has occurred is operation data acquired at intervals equal to or less than a first threshold value. For example, the first threshold value is five minutes. The control unit 10 can determine whether a first refrigerant leak has occurred by using the amount of change or rate of change in the operation data relating to the temperature and pressure of the refrigeration and air conditioning equipment 20 and the leak gas detection sensor data.

[0046] The control unit 10 determines whether a second refrigerant leak exists from the operating data of the refrigeration and air conditioning equipment 20. The data for determining whether a second refrigerant leak exists is operating data equal to or greater than a second threshold. For example, the second threshold is one week. The data for determining whether a second refrigerant leak exists can be acquired at any time interval. Note that the data for determining whether a second refrigerant leak exists may be operating data equal to or greater than the second threshold and data obtained by processing the operating data equal to or greater than the second threshold.

[0047] When the control unit 10 detects a first refrigerant leak, it changes the operating state of the refrigeration and air conditioning equipment 20 or the external equipment 50 linked to the refrigeration and air conditioning equipment 20. For example, when the control unit 10 detects a first refrigerant leak, it stops the operation of the refrigeration and air conditioning equipment 20. Also, for example, when the control unit 10 detects a first refrigerant leak, it starts the operation of the external equipment 50, such as a shutoff valve that shuts off the refrigerant piping of the equipment, a ventilation fan, a siren, an alarm device, etc. (for example, ventilating with a ventilation fan, or warning a user of the refrigeration and air conditioning equipment 20 by sounding a siren or an alarm device).

[0048] When the control unit 10 detects a second refrigerant leak, it does not change the operating state of the refrigeration and air conditioning equipment 20 or the external equipment 50 linked to the refrigeration and air conditioning equipment 20.

[0049] <First refrigerant leak and second refrigerant leak> Here, the first refrigerant judgment and the second refrigerant judgment will be described. For example, the first refrigerant leakage is a refrigerant leakage speed equal to or greater than a predetermined threshold (e.g., 1 kg / h), and the second refrigerant leakage is a refrigerant leakage speed less than the predetermined threshold (e.g., 1 kg / h). That is, the control unit 10 can judge the first refrigerant leakage as a rapid leakage and the second refrigerant leakage as a slow leak. For example, a rapid leakage is a refrigerant leakage that may cause oxygen deficiency or the flammable refrigerant to reach an ignition concentration if left unattended, and a slow leak is a refrigerant leakage that is not likely to cause oxygen deficiency or reach an ignition concentration even if left unattended, but may cause a performance degradation of the refrigeration and air conditioning equipment in the future.

[0050] The operating data, physical phenomenon to be detected, judgment logic, and judgment threshold used by the control unit to determine a first refrigerant leak are different from the operating data, physical phenomenon to be detected, judgment logic, and judgment threshold used by the control unit to determine a second refrigerant leak.

[0051] Specifically, to respond to rapid leaks, the detection logic can be simple, but data must be acquired on the order of seconds or minutes.On the other hand, to respond to slow leaks, the data acquisition interval can be on the order of hours or days, but complex detection logic such as machine learning models is required to estimate slight decreases in the amount of refrigerant from operational data, and a database is required to accumulate operational data and calculation data to determine past trends.

[0052] The difference between the two physical phenomena is that, for example, when using changes in temperature and pressure due to leakage, a rapid leak detects a transient, unsteady change in value caused by liquid refrigerant spraying out and vaporizing, whereas a slow leak detects changes in temperature and pressure in a steady state that become apparent after a long period of time, since only a small amount of refrigerant leaks, and as another example, a rapid leak detects the concentration of refrigerant gas leaked around the refrigeration and air conditioning equipment, whereas a slow leak detects fluorescent agents mixed into the refrigeration oil that seeps out from the leaking area when exposed to ultraviolet light, and so on.

[0053] As will be described in detail with reference to Figures 2 and 3, a control unit (processor) for determining a first refrigerant leak and a control unit (processor) for leaking a second refrigerant may be installed in the refrigeration and air conditioning equipment 20, the external controller 30, and the server 40.

[0054] <Configuration example> Fig. 2 and Fig. 3 show an example of the overall configuration of the present disclosure. Fig. 2 shows <Example 1> and <Example 2>. Fig. 3 shows <Example 3>, <Example 4>, and <Example 5>.

[0055] As shown in <Example 1> and <Example 2> in Figure 2, the refrigerant leak detection system 1 includes a refrigeration and air conditioning equipment 20 and a server 40, and a control unit that determines a first refrigerant leak and a control unit that determines a second refrigerant leak can be installed in the refrigeration and air conditioning equipment 20, an external controller 30 of the refrigeration and air conditioning equipment 20, and the server 40.

[0056] For example, as shown in <Example 1>, a control unit that determines whether a first refrigerant leak has occurred is installed in the external controller 30 of the refrigeration and air conditioning equipment 20, and a control unit that determines whether a second refrigerant leak has occurred is installed in the server 40. The external controller 30 can process the operating data and transmit the processed operating data to the server 40.

[0057] For example, as shown in <Example 2>, a control unit that determines whether a first refrigerant leak has occurred is installed in a refrigeration and air conditioning equipment 20 (which may be an indoor unit or an outdoor unit), and a control unit that determines whether a second refrigerant leak has occurred is installed in a server 40.

[0058] As described above, in <Example 1> and <Example 2>, the refrigeration and air conditioning equipment 20 (e.g., outdoor unit) or the external controller 30 installed on-site can detect a quick leak using operation data with a short sampling period and simple logic, and transmit only the detection result to the server 40. Also, the refrigeration and air conditioning equipment 20 (e.g., outdoor unit) or the external controller 30 installed on-site can transmit operation data to the server 40 with a long sampling period that allows detection of a slow leak, and the server 40 can store the transmitted data and detect a slow leak using the stored long-term data.

[0059] Therefore, data communication costs can be reduced compared to when the refrigeration and air conditioning equipment 20 and the external controller 30 transmit data acquired at short intervals to the server 40 and the server 40 responds to both rapid and slow leak modes. Also, equipment costs can be reduced compared to when the refrigeration and air conditioning equipment 20 and the external controller 30 do not transmit operating data to the server 40 and respond to both rapid and slow leak modes (in other words, the control board of the refrigeration and air conditioning equipment 20 and the external controller 30 require advanced calculation functions and database functions).

[0060] As shown in <Example 3>, <Example 4>, and <Example 5> in Figure 3, the refrigerant leak detection system 1 includes a refrigeration and air conditioning equipment 20 and a server 40, and the control unit 10 can be installed in any of the refrigeration and air conditioning equipment 20, the external controller 30 of the refrigeration and air conditioning equipment 20, or the server 40.

[0061] For example, as shown in <Example 3>, a control unit (a control unit for determining a first refrigerant leakage and a control unit for determining a second refrigerant leakage) 10 is installed in a refrigeration and air conditioning equipment 20 (which may be an indoor unit or an outdoor unit).

[0062] For example, as shown in <Example 4>, an external controller 30 is provided with a control unit (a control unit for determining whether a first refrigerant leak occurs and a control unit for determining whether a second refrigerant leak occurs) 10.

[0063] For example, as shown in <Example 5>, a server 40 is provided with a control unit (a control unit for determining whether a first refrigerant leak occurs and a control unit for determining whether a second refrigerant leak occurs) 10.

[0064] The hardware configuration of the air conditioning system 100 will be described with reference to Figs. 4 to 8. The air conditioning system 100 may be any air conditioning system such as a multi-air conditioner for a building, a central air conditioning system using a chiller as a heat source, an air conditioner for a store or office, or a room air conditioner, and may be a refrigeration or freezing system as well as a cooling and heating system. The air conditioning system 100 may have a plurality of indoor units 300. The plurality of indoor units 300 may include indoor units with different performance, may include indoor units with the same performance, or may include indoor units that are stopped.

[0065] <Hardware configuration of air conditioning system (for cooling operation)> 4 is a hardware configuration diagram of an air conditioning system (in cooling operation) 100 according to an embodiment of the present disclosure. The air conditioning system 100 has an outdoor unit 200 and one or more indoor units 300.

[0066] In the example of FIG. 4, the outdoor heat exchanger 201, the outdoor unit main expansion valve 205, the subcooling heat exchanger 203, the indoor heat exchanger expansion valve 302, the indoor heat exchanger 301, the four-way switching valve 206, and the compressor 202 are connected by refrigerant piping to form a main refrigerant circuit. The four-way switching valve 206 is set to supply the discharge gas of the compressor 202 to the outdoor heat exchanger 201. In the example of FIG. 4, a subcooling heat exchanger expansion valve 204 is further provided in a bypass piping connected from the piping between the outdoor heat exchanger 201 and the subcooling heat exchanger 203 to the piping on the suction side of the compressor 202. The subcooling heat exchanger 203 is a heat exchanger that exchanges heat between the refrigerant that has passed through the subcooling heat exchanger expansion valve 204 provided in the bypass piping connected from the piping between the outdoor heat exchanger 201 and the subcooling heat exchanger 203 to the piping on the suction side of the compressor 202 and the refrigerant in the main refrigerant circuit. The bypass example in FIG. 4 is just one example.

[0067] <<Outdoor unit>> On the outdoor unit 200 side, an outdoor heat exchanger 201, a compressor 202, a subcooling heat exchanger 203, a subcooling heat exchanger expansion valve (bypass circuit) 204, and an outdoor unit main expansion valve (main refrigerant circuit) 205 are connected to piping. The outdoor unit 200 has various sensors (temperature sensors (e.g., thermistors) (1), (3), (4), (6), (7) and pressure sensors (2), (5), etc.).

[0068] <<Indoor unit>> On the indoor unit 300 side, an indoor heat exchanger 301 and an indoor heat exchanger expansion valve 302 are connected to piping. The indoor unit 300 has various sensors (temperature sensors (e.g., thermistors) (8), (9), etc.).

[0069] <Hardware configuration of air conditioning system (for heating operation)> 5 is a hardware configuration diagram of an air conditioning system (in heating operation) 100 according to an embodiment of the present disclosure. The air conditioning system 100 has an outdoor unit 200 and one or more indoor units 300.

[0070] 5, the outdoor heat exchanger 201, the compressor 202, the four-way switching valve 206, the indoor heat exchanger 301, the indoor heat exchanger expansion valve 302, the subcooling heat exchanger 203, and the outdoor unit main expansion valve 205 are connected by refrigerant piping to configure a main refrigerant circuit. The four-way switching valve 206 has a flow path set so as to supply the discharge gas of the compressor 202 to the indoor heat exchanger 301.

[0071] <<Outdoor unit>> On the outdoor unit 200 side, an outdoor heat exchanger 201, a compressor 202, a subcooling heat exchanger 203, a subcooling heat exchanger expansion valve (bypass circuit) 204, and an outdoor unit main expansion valve (main refrigerant circuit) 205 are connected to piping. The outdoor unit 200 has various sensors (temperature sensors (e.g., thermistors) (1), (3), (4), (6), (7) and pressure sensors (2), (5), etc.).

[0072] <<Indoor unit>> On the indoor unit 300 side, an indoor heat exchanger 301 and an indoor heat exchanger expansion valve 302 are connected to piping. The indoor unit 300 has various sensors (temperature sensors (e.g., thermistors) (8), (9), etc.).

[0073] <Hardware configuration of air conditioning system (for simultaneous cooling and heating operation)> The present disclosure is not limited to application to cooling operation and heating operation, but can also be applied to simultaneous cooling and heating operation. Simultaneous cooling and heating operation will be described below with reference to FIG.

[0074] Fig. 6 is a hardware configuration diagram of an air conditioning system (in the case of simultaneous cooling and heating operation) 100 according to an embodiment of the present disclosure. In the air conditioning system 100, outdoor heat exchangers 201-1 and 201-2, which are divided into two parts, and multiple indoor units are connected by three communication pipes, and simultaneous cooling and heating operation is possible. Fig. 6 shows an example of cooling-dominated operation, in which the indoor unit 300-1 is operated in heating mode and the indoor unit 300-2 is operated in cooling mode. At this time, the outdoor heat exchanger 201-1 functions as a condenser, and the outdoor heat exchanger 201-2 functions as an evaporator.

[0075] 7 shows an example of a case where at least one of the heat source side and the utilization side is a water-cooled type when an economizer circuit according to an embodiment of the present disclosure is included. The refrigeration and air conditioning equipment 20 according to an embodiment of the present disclosure includes an economizer circuit.

[0076] 8 is an example of a case in which an intermediate injection circuit according to an embodiment of the present disclosure is provided. The refrigeration and air conditioning equipment 20 according to an embodiment of the present disclosure has an intermediate injection circuit.

[0077] <Hardware configuration of external controller and server> FIG. 9 is a hardware configuration diagram of the external controller 30 and the server 40 according to an embodiment of the present disclosure.

[0078] The external controller 30 and the server 40 each include a central processing unit (CPU) 1001, a read only memory (ROM) 1002, and a random access memory (RAM) 1003. The CPU 1001, the ROM 1002, and the RAM 1003 form a so-called computer.

[0079] Furthermore, the external controller 30 and the server 40 may have an auxiliary storage device 1004, a display device 1005, an operation device 1006, and an I / F (Interface) device 1007. The hardware components of the external controller 30 and the server 40 are connected to each other via a bus 1008.

[0080] The CPU 1001 is a computing device that executes various programs installed in the auxiliary storage device 1004 .

[0081] The ROM 1002 is a non-volatile memory. The ROM 1002 functions as a main storage device that stores various programs, data, etc. required for the CPU 1001 to execute various programs installed in the auxiliary storage device 1004. Specifically, the ROM 1002 functions as a main storage device that stores boot programs such as a BIOS (Basic Input / Output System) and an EFI (Extensible Firmware Interface).

[0082] The RAM 1003 is a volatile memory such as a dynamic random access memory (DRAM) or a static random access memory (SRAM). The RAM 1003 functions as a main storage device that provides a working area in which various programs installed in the auxiliary storage device 1004 are expanded when the CPU 1001 executes them.

[0083] The auxiliary storage device 1004 is an auxiliary storage device that stores various programs and information used when the various programs are executed.

[0084] The display device 1005 is a display device that displays the internal states of the external controller 30 and the server 40, etc.

[0085] The operation device 1006 is an input device through which an administrator of the external controller 30 and the server 40 inputs various instructions to the external controller 30 and the server 40 .

[0086] The I / F device 1007 is a communication device that connects to various sensors and networks and communicates with other terminals.

[0087] <Function block> Fig. 10 is a functional block diagram of the control unit 10 according to an embodiment of the present disclosure. As shown in Fig. 10, the control unit 10 includes a driving data acquisition unit 101, a first determination unit 103, an external device change unit 104, a driving data processing unit 105, and a second determination unit 106. The control unit 10 also executes a program to function as the driving data acquisition unit 101, the first determination unit 103, the external device change unit 104, the driving data processing unit 105, and the second determination unit 106. Each of these units will be described below.

[0088] The operation data acquisition unit 101 acquires operation data of the refrigeration and air conditioning equipment 20. The operation data is data that can be acquired during operation of the refrigeration and air conditioning equipment 20. Specifically, the operation data includes output values ​​of sensors that measure temperature, pressure, current, gas concentration, etc. mounted on the refrigeration and air conditioning equipment 20, and command values ​​to the compressor, fan motor, motor-operated valve, etc. The operation data acquisition unit 101 supplies the acquired operation data to a first judgment unit 103, an operation data processing unit 105, and a second judgment unit 106. The operation data storage unit 102 stores the operation data acquired by the operation data acquisition unit 101 and the processed data processed by the operation data processing unit 105. Note that the data to be stored may be either the operation data or the processed data.

[0089] <Example of operation data> Here, an example of the operation data of the refrigeration and air conditioning equipment 20 will be described.

[0090] <<Operation data (example 1)>> For example, the driving data is Refrigerant gas concentration around refrigeration and air conditioning equipment 20 Outside temperature - Compressor 202 rotation speed Opening degree of the expansion valve 204 of the subcooling heat exchanger Current value of compressor 202 It may include at least one of the following:

[0091] <<Operation data (example 2)>> For example, the driving data may be, in addition to or instead of the driving data (example 1) above, Opening degree of indoor unit expansion valve 302 Opening degree of outdoor unit main expansion valve 205 - Total rated capacity of indoor units in operation or standby Number of indoor units in operation ·Indoor capacity (cooling or heating) Indoor unit outlet temperature ·room temperature Condensation temperature Evaporation temperature - Outdoor unit liquid shutoff valve connecting piping refrigerant temperature (connecting piping liquid temperature detected by thermistor (4) in Figures 4 and 5) Liquid connection pipe refrigerant temperature (temperature measured at the connection pipe outside the outdoor unit 200 detected by an external sensor attached to the outside of the outdoor unit 200) Outdoor unit fan air volume Indoor unit fan air volume Outdoor unit fan speed (step, tap) Indoor unit fan speed (step, tap) Outdoor unit fan current value Indoor unit fan current value ·Refrigerant circulation amount Discharge temperature of compressor 202 Compressor 202 suction temperature Compressor 202 discharge superheat Compressor 202 suction superheat Degree of subcooling at the outlet of the subcooling heat exchanger 203 (if a subcooling heat exchanger circuit is provided) Outlet superheat degree of the subcooling heat exchanger 203 (gas pipe side) (if a subcooling heat exchanger circuit is included) Economizer outlet subcooling degree (if economizer circuit is installed) Economizer expansion valve opening (if an economizer circuit is included) Economizer bypass outlet pressure (if economizer circuit is installed) - Opening degree of intermediate injection expansion valve (if intermediate injection circuit is provided) - Intermediate injection temperature (if intermediate injection circuit is included) - Intermediate injection pressure (if intermediate injection circuit is installed) Evaporator inlet water temperature (when at least one of the heat source side and the user side is water-cooled) - Evaporator outlet water temperature (when at least one of the heat source side and the user side is water-cooled) -Condenser inlet water temperature (when at least one of the heat source side and the user side is water-cooled) - Condenser outlet water temperature (when at least one of the heat source side and the user side is water-cooled) It may include at least one of the following:

[0092] <<Operation data (example 3)>> For example, the driving data may be, in addition to or instead of the driving data (examples 1 and 2) described above, At least one of the number of defrosts and the defrost time may be included.

[0093] Returning to the explanation of Figure 10.

[0094] The first determination unit 103 determines whether or not a first refrigerant leak has occurred from the operating data acquired by the operating data acquisition unit 101. The data for determining whether or not a first refrigerant leak has occurred is operating data acquired at intervals equal to or less than a first threshold value (e.g., 5 minutes). For example, the first determination unit 103 can determine whether or not a first refrigerant leak has occurred by using the amount of change or rate of change in the operating data related to the temperature and pressure of the refrigeration and air conditioning equipment 20, and the sensor data for detecting the leaking gas.

[0095] The second determination unit 106 determines the second refrigerant from the operating data acquired by the operating data acquisition unit 101. The data for determining whether or not there is a second refrigerant leak is operating data for a period equal to or greater than a second threshold (for example, one week). The data for determining whether or not there is a second refrigerant leak may be operating data for a period equal to or greater than the second threshold and data obtained by processing the operating data for a period equal to or greater than the second threshold. For example, the second determination unit 106 can estimate whether or not there is a second refrigerant leak from the operating data or the calculation data using a machine-learned model.

[0096] The external equipment change unit 104 changes the operating state of the refrigeration and air conditioning equipment 20 or the external equipment 50 when the first determination unit 103 detects a first refrigerant leakage. For example, the external equipment change unit 104 stops the operation of the refrigeration and air conditioning equipment 20 when a first refrigerant leakage is detected. Also, for example, when a first refrigerant leakage is detected, the external equipment change unit 104 starts the operation of the external equipment 50, such as a ventilation fan, a refrigerant piping shutoff valve, a siren, an alarm device, etc. (for example, ventilating with a ventilation fan, shutting off the refrigerant supply to the leaking part with a refrigerant piping shutoff valve, warning the user of the refrigeration and air conditioning equipment 20 by sounding a siren or an alarm device).

[0097] The operation data processing unit 105 processes the operation data acquired by the operation data acquisition unit 101. For example, the operation data processing unit 105 can thin out the operation data (for example, extract data at regular intervals, or calculate the average, median, mode, etc. within the regular interval and use the value as the representative value of the interval). In addition, for example, the operation data processing unit 105 can calculate the operation data to create new data (for example, SC (subcool), SH (superheat), and refrigerant amount index value).

[0098] SC (subcool) refers to the degree of subcooling of the refrigerant.

[0099] SH (superheat) refers to the degree of superheat of the refrigerant.

[0100] The refrigerant amount index value is, for example, as follows:

[0101] <<Refrigerant amount index (Example 1 (cooling operation))>> For example, the refrigerant amount index value is Condensation temperature-Outlet temperature of the outdoor heat exchanger 201 (hereinafter also referred to as the outdoor heat exchanger outlet subcooling degree. Note that the subcooling degree is also called SC or subcool) Compressor intake superheat (superheat is also called SH or superheat) Compressor discharge superheat - Value based on the outdoor heat exchanger outlet subcooling degree or compressor suction superheat degree or compressor discharge superheat degree It may include at least one of the following:

[0102] For example, the value based on the degree of subcooling at the outlet of the outdoor heat exchanger is a calculated value using the degree of subcooling at the outlet of the outdoor heat exchanger. Calculated value using the degree of subcooling at the outlet of the outdoor heat exchanger = degree of subcooling at the outlet of the outdoor heat exchanger / (condensing temperature - outdoor temperature) It is.

[0103] For example, the value based on the degree of subcooling at the outlet of the outdoor heat exchanger is a value defined from the refrigerant properties and the refrigeration cycle diagram (TS, Ph diagram).

[0104] <<Refrigerant amount index (Example 2 (cooling operation))>> For example, the refrigerant amount index value may be, in addition to the above refrigerant amount index value (Example 1), or instead of the outdoor heat exchanger outlet subcooling degree of the above refrigerant amount index value (Example 1), ·Subcooling heat exchanger outlet subcooling degree - Value based on the degree of subcooling at the outlet of the subcooling heat exchanger It may include at least one of the following:

[0105] <<Refrigerant amount index (Example 3 (heating operation))>> In the case of heating operation, the refrigerant amount index value is set to the following instead of the above refrigerant amount index value (Example 1 and Example 2): The degree of subcooling at the indoor heat exchanger outlet may include at least one of the following: a degree of subcooling at the indoor heat exchanger outlet, and a value based on the degree of subcooling at the indoor heat exchanger outlet. The degree of subcooling at the indoor heat exchanger outlet is at least one of the degrees of subcooling at the multiple indoor heat exchangers 301, an average of the degrees of subcooling at the multiple indoor heat exchangers 301, or a degree of subcooling at the indoor side junction or the outdoor side junction of the multiple indoor heat exchangers 301.

[0106] <<Refrigerant amount index (Example 4 (simultaneous cooling and heating operation))>> In the case of simultaneous cooling and heating operation, in addition to the above refrigerant amount index value, A combination of the outlet subcooling degree of the indoor heat exchanger (the indoor heat exchanger 301 of the heating indoor unit 300-1 in FIG. 6) and the outlet subcooling degree of the outdoor heat exchanger (the outdoor heat exchanger (condenser) 201-1 in FIG. 6).

[0107] <Method> FIG. 11 is a flowchart of a refrigerant leakage detection process according to an embodiment of the present disclosure.

[0108] In step 1 (S1), the control unit 10 acquires operation data of the refrigeration and air conditioning equipment 20.

[0109] In step 2 (S2), the control unit 10 determines whether there is a first refrigerant leak from the operating data acquired in S1. The control unit 10 also determines whether there is a second refrigerant leak from the operating data acquired in S1. The data for determining whether there is a first refrigerant leak is operating data acquired at intervals equal to or less than a first threshold value (e.g., 5 minutes). The data for determining whether there is a second refrigerant leak is operating data equal to or more than a second threshold value (e.g., 1 week). The data for determining whether there is a second refrigerant leak may be operating data equal to or more than a second threshold value (e.g., 1 week) and data obtained by processing the operating data equal to or more than the second threshold value (e.g., 1 week).

[0110] FIG. 12 shows the relationship between the refrigerant leakage rate and the total charge leakage time when a rapid leakage occurs in a multi-air conditioner for buildings with an average refrigerant charge amount (20 kg). In the figure, the points corresponding to rapid leakage and burst leakage defined in the guideline "Appropriate measures to prevent combustion when refrigerant gas leaks from refrigerant equipment using specific inert gas (JRA GL-20)" of the Japan Refrigeration and Air Conditioning Industry Association are described. Rapid leakage (10 kg / h) is the maximum leakage rate that can occur in an indoor unit, and burst leakage (75 kg / h) is the maximum leakage rate that can occur in an outdoor unit. In the case of an average refrigerant amount of 20 kg, the entire refrigerant is released into the atmosphere in 120 minutes when a rapid leakage occurs, and in 16 minutes when a burst leakage occurs. By setting the first threshold value to 5 minutes or less, even if such a rapid refrigerant leakage occurs, the control unit 10 reliably detects it and changes the operating state of the external device 50 to prevent oxygen deficiency and fire accidents.

[0111] 13 shows the daily SC for a year for a multi-air conditioner for a building where a slow leak has occurred, and the predicted daily SC during normal operation predicted from other operation data for that year. Here, SC is the representative SC value for each day calculated by the operation data processing unit 105, and the predicted SC is the predicted value of the representative SC value for each day calculated by the normal SC prediction model built into the second judgment unit 106.

[0112] FIG. 14 shows the refrigerant amount index value ΔSC defined as the difference between the SC and the predicted SC, and the 7-day moving average and 14-day moving average of ΔSC. If one were to make a judgment based only on the current value of ΔSC, it would be difficult to judge the occurrence of the leak, which is assumed to have occurred since the latter half of March, immediately after the occurrence, because of the large fluctuations due to factors other than the change in the amount of refrigerant. In contrast, the moving average data of ΔSC, which is processed from the operation data for 7 days (1 week) as the second threshold, smooths out the fluctuations, so that the downward trend due to the leak from the latter half of March can be confirmed. Furthermore, if the threshold is changed to 14 days (2 weeks), the tendency of the leak can be judged more clearly. For example, it is expected that the accuracy of the judgment will be improved by using the expansion valve opening of the operation data and ΔSC of the operation processed data in combination.

[0113] In one embodiment of the present disclosure, the control unit 10 can control the operating states of the refrigeration and air conditioning equipment 20 and the external equipment 50 after determining the first refrigerant leakage and the second refrigerant leakage in S2. When the control unit 10 detects a first refrigerant leakage after determining the refrigerant leakage in S2, the control unit 10 changes the operating state of the refrigeration and air conditioning equipment 20 or the external equipment 50 linked to the refrigeration and air conditioning equipment 20. Furthermore, when the control unit 10 detects a second refrigerant leakage after determining the refrigerant leakage in S2, the control unit 10 does not change the operating state of the refrigeration and air conditioning equipment 20 or the external equipment 50 linked to the refrigeration and air conditioning equipment 20.

[0114] Although the embodiments have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. [Explanation of symbols]

[0115] 1 Refrigerant leak detection system 10 Control section 20 Refrigeration and air conditioning equipment 30 External Controller 40 Servers 50 External equipment 60 Storage device 100 Air Conditioning System 200 outdoor unit 201 Outdoor heat exchanger 201-1 Outdoor heat exchanger (condenser) 201-2 Outdoor heat exchanger (evaporator) 202 Compressor 203 Supercooling heat exchanger 204 Subcooling heat exchanger expansion valve 205 Outdoor unit main expansion valve 206 Four-way switching valve 207 Economizer 208 Economizer expansion valve 209 Main expansion valve 210 Condenser 211 Evaporator 212 Intermediate injection expansion valve 213 Condenser 214 Evaporator 300 indoor unit 300-1 Indoor heating unit 300-2 Cooling indoor unit 301 Indoor heat exchanger 302 Indoor heat exchanger expansion valve 101 Operation data acquisition unit 102 Operation data storage unit 103 1st Judgment Section 104 External device change section 105 Operation Data Processing Department 106 Second Judgment Section 1001 CPU 1002 ROM 1003 RAM 1004 Auxiliary storage device 1005 Display device 1006 Operating device 1007 I / F device 1008 Bus

Claims

1. A refrigerant leak detection system including a refrigeration and air conditioning device and a server, The control unit of the refrigeration and air conditioning equipment or the control unit of the external controller of the refrigeration and air conditioning equipment Acquire operating data of the refrigeration and air conditioning equipment; determining a rapid leak from the operational data; The control unit of the server Acquire operating data of the refrigeration and air conditioning equipment; A slow leak is determined from the operating data; The data for determining whether a rapid leak occurs is operating data acquired at short intervals, The data for determining the slow leak is operation data acquired over a long period of time, The control unit of the server does not acquire the operating data acquired at the short interval, and the logic for determining the rapid leak is easier than the logic for determining the slow leak. Refrigerant leak detection system.

2. 2. The refrigerant leak detection system of claim 1, wherein the short interval is five minutes or less and the long interval is one week or more.

3. 3. The refrigerant leakage detection system according to claim 1, wherein the data for determining whether or not a slow leak occurs is the operation data acquired over the long period of time and data obtained by processing the operation data acquired over the long period of time.

4. The control unit that determines the rapid leakage changes an operating state of the refrigeration / air conditioning equipment or an external equipment linked to the refrigeration / air conditioning equipment when the rapid leakage is detected, The refrigerant leakage detection system according to claim 1 , wherein the control unit that determines the slow leak does not change an operating state of the refrigeration and air conditioning equipment or the external equipment when the control unit detects the slow leak.

5. The refrigerant leak detection system according to claim 1 , wherein the rapid leak is a refrigerant leak rate equal to or higher than a threshold, and the slow leak is a refrigerant leak rate less than the threshold.

6. 6. The refrigerant leakage detection system according to claim 1, wherein the operating data, the physical phenomenon to be detected, the judgment logic, and the judgment threshold value used by the control unit to determine the rapid leak are different from the operating data, the physical phenomenon to be detected, the judgment logic, and the judgment threshold value used by the control unit to determine the slow leak.

7. 7. The refrigerant leakage detection system according to claim 6, wherein the control unit that determines whether a rapid leakage has occurred uses a change amount or a change rate of operating data related to the temperature and pressure of the refrigeration and air conditioning equipment, and leaking gas detection sensor data.

8. The refrigerant leakage detection system according to claim 1 , wherein the control unit that determines whether a rapid leak occurs processes the operating data and transmits the processed operating data to the control unit that determines whether a slow leak occurs.

9. The refrigerant leak detection system according to claim 8 , wherein the processing comprises thinning out the operating data.

10. The refrigerant leakage detection system according to claim 8 , wherein the processing comprises calculating the operating data to create new data.

11. The refrigerant leakage detection system according to claim 1 , wherein a result of the rapid leakage determination and a result of the slow leakage determination are stored in a storage device.

12. A method executed by a refrigerant leak detection system including a refrigeration and air conditioning device and a server, comprising: A control unit of the refrigeration and air conditioning equipment or a control unit of an external controller of the refrigeration and air conditioning equipment, Acquiring operation data of the refrigeration and air conditioning equipment; determining from the operational data whether a rapid leak has occurred; A control unit of the server Acquiring operation data of the refrigeration and air conditioning equipment; determining a slow leak from the operating data; The data for determining whether a rapid leak occurs is operating data acquired at short intervals, The data for determining the slow leak is operation data acquired over a long period of time, The control unit of the server does not acquire the operating data acquired at the short interval, and the logic for determining the rapid leak is easier than the logic for determining the slow leak. method.

13. A control unit of a refrigeration and air conditioning device or a control unit of an external controller of the refrigeration and air conditioning device, A procedure for acquiring operation data of the refrigeration and air conditioning equipment; and determining whether a rapid leak occurs based on the operational data. In the server's control section, A procedure for acquiring operation data of the refrigeration and air conditioning equipment; and executing a procedure for determining whether a slow leak occurs based on the operational data; The data for determining whether a rapid leak occurs is operating data acquired at short intervals, The data for determining the slow leak is operation data acquired over a long period of time, The control unit of the server does not acquire the operating data acquired at the short interval, and the logic for determining the rapid leak is easier than the logic for determining the slow leak. program.

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