Refrigerant leak detection device, refrigerant leak detection method, and refrigerant leak detection system

Abstract

To provide a refrigerant leak detection device, a refrigerant leak detection method, and a refrigerant leak detection system that can detect refrigerant leaks from the refrigerant circuit of a refrigeration cycle system more quickly. [Solution] A refrigerant leak detection device 30 having a control unit 32, the control unit 32 acquires operating data of the refrigeration cycle device 10 and detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 based on values ​​related to the subcooling expansion valve 22 or economizer expansion valve 42 and values ​​related to the discharge pipe temperature of the refrigeration cycle device 10 included in the operating data.

Description

Technical Field

[0001] The present disclosure relates to a refrigerant leakage detection device, a refrigerant leakage detection method, and a refrigerant leakage detection system.

Background Art

[0002] In a refrigeration cycle device including a receiver (surplus refrigerant reservoir), a technique for determining the refrigerant amount using a value related to the degree of subcooling at the outlet of the subcooling heat exchanger measured is conventionally known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The subcooling expansion valve controls so that the degree of subcooling at the outlet of the subcooling heat exchanger during the cooling operation and the degree of heating at the outlet of the subcooling heat exchanger gas pipe during the heating operation become constant. The refrigerant discharged from the condenser is divided into the refrigerant flowing to the suction side of the compressor through the subcooling expansion valve and the refrigerant flowing to the evaporator, and heat exchange is performed between them. Therefore, the fact that the degree of heating at the outlet of the subcooling heat exchanger gas pipe is controlled to be constant means that, indirectly, the degree of subcooling is also controlled to be constant, and the degree of subcooling does not change until the subcooling expansion valve is fully opened during both the cooling operation and the heating operation.

[0005] Furthermore, the degree of subcooling at the outlet of the subcooled heat exchanger has a low resolution, as the difference in temperature between normal conditions (no leak) and leak conditions is only a few degrees Celsius. Moreover, in refrigeration cycle systems that include a receiver (excess refrigerant storage), even if a refrigerant leak occurs while refrigerant is accumulated inside the receiver, the refrigerant leak is replenished from the refrigerant accumulated in the receiver into the refrigerant circuit. Therefore, the state of the refrigeration cycle does not change, and the value related to the degree of subcooling does not change, making it impossible to detect the leak. In short, in refrigeration cycle systems that include a receiver, leak detection is only possible after a refrigerant equivalent to the amount accumulated in the receiver has leaked.

[0006] This disclosure aims to provide a refrigerant leak detection device, a refrigerant leak detection method, and a refrigerant leak detection system that can detect refrigerant leaks from the refrigerant circuit of a refrigeration cycle device more quickly. [Means for solving the problem]

[0007] A first aspect of the present disclosure is a refrigerant leak detection device having a control unit, the control unit acquires operating data of a refrigeration cycle device, and detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle device based on values ​​related to a subcooling expansion valve or an economizer expansion valve and values ​​related to the discharge pipe temperature of the refrigeration cycle device included in the operating data.

[0008] According to a first aspect of this disclosure, a refrigerant leak detection device can be provided that can detect refrigerant leaks from the refrigerant circuit of a refrigeration cycle system more quickly.

[0009] A second aspect of this disclosure is a refrigerant leak detection device according to the first aspect, wherein the control unit outputs normal predicted values ​​for the subcooling expansion valve or economizer expansion valve using a first normal prediction model of values ​​for the subcooling expansion valve or economizer expansion valve that has been trained on the operating data of the refrigeration cycle device under normal conditions, and detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle device based on the normal predicted values ​​for the subcooling expansion valve or economizer expansion valve and the measured values ​​for the subcooling expansion valve or economizer expansion valve included in the operating data.

[0010] According to a second aspect of this disclosure, refrigerant leakage from the refrigerant circuit of a refrigeration cycle system can be detected based on a normal predicted value for the subcooled expansion valve or economizer expansion valve and an actual measured value for the subcooled expansion valve or economizer expansion valve included in the operating data.

[0011] A third aspect of the present disclosure is a refrigerant leak detection device according to the first or second aspect, wherein the control unit outputs a normal predicted value for the discharge pipe temperature of the refrigeration cycle device using a second normal prediction model of values ​​for the discharge pipe temperature of the refrigeration cycle device that has been trained on the operating data of the refrigeration cycle device under normal conditions, and detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle device based on the normal predicted value for the discharge pipe temperature of the refrigeration cycle device and the measured value for the discharge pipe temperature of the refrigeration cycle device.

[0012] According to a third aspect of this disclosure, refrigerant leakage from the refrigerant circuit of a refrigeration cycle device can be detected based on a normal predicted value for the discharge pipe temperature of the refrigeration cycle device and an actual measured value for the discharge pipe temperature of the refrigeration cycle device.

[0013] A fourth aspect of the present disclosure is a refrigerant leak detection device according to any one of the first to third aspects, wherein the control unit detects a refrigerant leak from the refrigerant circuit of the refrigeration cycle device if at least one of the results of detecting a refrigerant leak from the refrigerant circuit of the refrigeration cycle device based on a value relating to a subcooling expansion valve or economizer expansion valve included in the operating data, and the result of detecting a refrigerant leak from the refrigerant circuit of the refrigeration cycle device based on a value relating to the discharge pipe temperature of the refrigeration cycle device indicates that a refrigerant leak is present.

[0014] According to a fourth aspect of this disclosure, refrigerant leakage from the refrigerant circuit of a refrigeration cycle device can be detected if at least one of the results of detecting refrigerant leakage from the refrigerant circuit of a refrigeration cycle device based on a value relating to a subcooling expansion valve or an economizer expansion valve, and the result of detecting refrigerant leakage from the refrigerant circuit of a refrigeration cycle device based on a value relating to the discharge pipe temperature, indicates that refrigerant leakage is present.

[0015] A fifth aspect of this disclosure is a refrigerant leak detection device according to any one of the first to fourth aspects, wherein the control unit detects a refrigerant leak from the refrigerant circuit of the refrigeration cycle device and issues an alert to the user associated with the refrigeration cycle device.

[0016] According to a fifth aspect of this disclosure, if a refrigerant leak from the refrigerant circuit of a refrigeration cycle system is detected, an alert can be sent to the user associated with the refrigeration cycle system.

[0017] A sixth aspect of this disclosure is a refrigerant leak detection device according to any one of the first to fifth aspects, wherein the value relating to the subcooling expansion valve is the opening degree of the subcooling expansion valve, the refrigerant flow rate ratio, the CV value, or a cooling capacity value calculated from the opening degree of the subcooling expansion valve.

[0018] According to a sixth aspect of this disclosure, the opening degree of the subcooling expansion valve, the refrigerant flow rate ratio, the CV value, or the cooling capacity value calculated from the opening degree of the subcooling expansion valve can be used as values ​​related to the subcooling expansion valve. The CV value is a coefficient that indicates the ease of fluid flow.

[0019] A seventh aspect of this disclosure is a refrigerant leak detection device according to any one of the first to fifth aspects, wherein the value relating to the economizer expansion valve is the opening degree of the economizer expansion valve, the refrigerant flow rate ratio, the CV value, or a cooling capacity value calculated from the opening degree of the economizer expansion valve.

[0020] According to a seventh aspect of this disclosure, the opening degree of the economizer expansion valve, the refrigerant flow rate ratio, the CV value, or the cooling capacity value calculated from the opening degree of the economizer expansion valve can be used as values ​​related to the economizer expansion valve.

[0021] The eighth aspect of the present disclosure is the refrigerant leakage detection device according to any one of the first to seventh aspects, wherein the value related to the discharge pipe temperature of the refrigeration cycle device is the discharge pipe temperature of the compressor of the refrigeration cycle device, or the discharge superheat degree of the compressor calculated based on the discharge pipe temperature of the compressor of the refrigeration cycle device and the condensation temperature of the condenser.

[0022] According to the eighth aspect of the present disclosure, the discharge pipe temperature of the compressor of the refrigeration cycle device, or the discharge superheat degree of the compressor calculated based on the discharge pipe temperature of the compressor of the refrigeration cycle device and the condensation temperature of the condenser, can be used as the value related to the discharge pipe temperature of the refrigeration cycle device.

[0023] The ninth aspect of the present disclosure is a refrigerant leakage detection method executed by a refrigerant leakage detection device having a control unit, wherein the control unit acquires operation data of a refrigeration cycle device, and based on the value related to the subcooling expansion valve or economizer expansion valve included in the operation data and the value related to the discharge pipe temperature of the refrigeration cycle device, detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle device.

[0024] According to the ninth aspect of the present disclosure, a refrigerant leakage detection method capable of detecting refrigerant leakage from the refrigerant circuit of a refrigeration cycle device earlier can be provided.

[0025] The tenth aspect of the present disclosure is a refrigerant leakage detection system having a refrigeration cycle device and an information processing device having a control unit, wherein the control unit acquires operation data of the refrigeration cycle device, and based on the value related to the subcooling expansion valve or economizer expansion valve included in the operation data and the value related to the discharge pipe temperature of the refrigeration cycle device, detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle device.

[0026] According to the tenth aspect of the present disclosure, a refrigerant leakage detection system capable of detecting refrigerant leakage from the refrigerant circuit of a refrigeration cycle device earlier can be provided.

Brief Description of the Drawings

[0027] [Figure 1]This is a diagram illustrating an example of the configuration of the refrigerant leak detection system 1 according to this embodiment. [Figure 2] This is a hardware configuration diagram of an example of computer 500 according to this embodiment. [Figure 3] This graph shows an example of the relationship between the amount of refrigerant in the refrigeration cycle device 10, the subcooling expansion valve 22, and the discharge superheat. [Figure 4] This is a flowchart of an example of a learning phase. [Figure 5] This is a flowchart of an example of the detection phase. [Figure 6] This is an explanatory diagram illustrating an example of processing in the detection phase. [Figure 7] This is an explanatory diagram illustrating an example of processing in the detection phase. [Figure 8] This is an explanatory diagram illustrating an example of processing in the detection phase. [Figure 9] This is a diagram illustrating an example of the configuration of the refrigerant leak detection system 1 according to this embodiment. [Modes for carrying out the invention]

[0028] Next, embodiments of this disclosure will be described in detail.

[0029] <System Configuration> Figure 1 is a configuration diagram of an example of a refrigerant leak detection system 1 according to this embodiment. The refrigerant leak detection system 1 in Figure 1 includes a refrigeration cycle device 10 and a refrigerant leak detection device 30. The refrigeration cycle device 10 is an air conditioning system or a refrigeration and freezing system, etc. The air conditioning system is a multi-split air conditioner for buildings, an air conditioner for shops, an air conditioner for offices, or a room air conditioner, etc.

[0030] Figure 1 shows the refrigeration cycle device 10 in the case of heating operation of an air conditioning system that can switch between cooling and heating operation. The refrigeration cycle device 10 consists of a compressor 12, a four-way switching valve 13, an indoor heat exchanger 14, an indoor expansion valve 16, a receiver 18, a subcooling heat exchanger 20, a subcooling expansion valve 22, an outdoor expansion valve 24, an outdoor heat exchanger 26, and an accumulator 28.

[0031] The compressor 12, four-way switching valve 13, indoor heat exchanger 14, indoor expansion valve 16, receiver 18, subcooling heat exchanger 20, subcooling expansion valve 22, outdoor expansion valve 24, outdoor heat exchanger 26, and accumulator 28 of the refrigeration cycle device 10 are connected by piping through which the refrigerant flows, forming a refrigerant circuit.

[0032] Furthermore, in the refrigeration cycle device 10 shown in Figure 1, a subcooling expansion valve 22 is provided in a bypass pipe connected from the piping between the indoor heat exchanger 14 and the subcooling heat exchanger 20 to the suction side piping of the compressor 12. The subcooling heat exchanger 20 is a heat exchanger that exchanges heat between the refrigerant that has passed through the subcooling expansion valve 22 and the refrigerant sent from the subcooling heat exchanger 20 to the outdoor expansion valve 24.

[0033] The outdoor compressor 12, receiver 18, subcooled heat exchanger 20, subcooled expansion valve 22, outdoor expansion valve 24, outdoor heat exchanger 26, and accumulator 28 are installed in the outdoor unit. The indoor heat exchanger 14 and indoor expansion valve 16 are installed in the indoor unit.

[0034] The refrigerant compressed by the compressor 12 flows into the indoor heat exchanger 14, which acts as a condenser, and is cooled and condensed through heat exchange with the indoor air. The refrigerant condensed in the indoor heat exchanger 14 passes through the receiver 18, where excess refrigerant is stored, and is supercooled in the supercooling heat exchanger 20.

[0035] This section explains excess refrigerant. The amount of refrigerant required in the refrigerant circuit varies depending on the operating conditions. In a refrigeration cycle device 10 that can switch between cooling and heating operations, more refrigerant is required during cooling operation than during heating operation, so the refrigerant amount is filled to match the cooling operation. Therefore, especially during heating operation, there is more refrigerant in the circuit than is necessary to output the required cooling capacity. This excess refrigerant present in the refrigerant circuit is called excess refrigerant. The receiver 18 plays the role of storing excess refrigerant and is also called an excess refrigerant reservoir. The receiver 18 may be omitted.

[0036] The refrigerant, supercooled in the supercooled heat exchanger 20, is depressurized in the outdoor expansion valve 24 and flows into the outdoor heat exchanger 26. The refrigerant that flows into the outdoor heat exchanger 26 vaporizes through heat exchange with the outside air, thereby absorbing heat of vaporization from the outside air. The refrigerant vaporized in the outdoor heat exchanger 26 flows into the accumulator 28.

[0037] The accumulator 28 functions as a buffer tank that stores excess liquid refrigerant when it flows in, thereby preventing liquid compression in the compressor 12. The accumulator 28 also regulates the dryness of the refrigerant.

[0038] The refrigeration cycle device 10 is equipped with various sensors on both the indoor and outdoor sides. The sensors provided on the indoor side are, for example, temperature sensors such as thermistors. The sensors provided on the outdoor side are, for example, temperature sensors such as thermistors and pressure sensors.

[0039] The refrigerant leak detection device 30 detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 based on values ​​related to the subcooling expansion valve 22 and the discharge pipe temperature of the refrigeration cycle device 10.

[0040] The refrigerant leak detection device 30 is connected via a communication network such as the Internet or a LAN (Local Area Network) so that it can acquire the data described later that is necessary for detecting refrigerant leaks from the refrigerant circuit of the refrigeration cycle device 10.

[0041] For example, the refrigerant leak detection device 30 acquires the data described later from the refrigeration cycle device 10 that is necessary to detect refrigerant leakage from the refrigerant circuit. The refrigerant leak detection device 30 may also acquire the data described later from a device other than the refrigeration cycle device 10 that stores the data necessary to detect refrigerant leakage from the refrigerant circuit. Details of the refrigerant leak detection device 30 will be described later.

[0042] The refrigerant leak detection device 30 has a control unit 32. The control unit 32 is a hardware configuration that executes programs. The control unit 32 can be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field Programmable Gate Array), etc. For example, the refrigerant leak detection device 30 can perform various processes described later by having a CPU, one example of the control unit 32, execute a program.

[0043] The configuration of the refrigerant leak detection system 1 shown in Figure 1 is an example. The refrigerant leak detection device 30 may be implemented using one or more information processing devices. Alternatively, the refrigerant leak detection device 30 may be implemented as a cloud computing service.

[0044] In Figure 1, the control unit 32 of the refrigerant leak detection device 30 is shown as an example, but the refrigeration cycle device 10 may also have a control unit. The various processes performed by the control unit 32 of the refrigerant leak detection device 30, as described later, may also be performed by the control unit of the refrigeration cycle device 10. The various processes performed by the control unit 32 of the refrigerant leak detection device 30 may also be performed in cooperation with the control unit of the refrigeration cycle device 10.

[0045] The configuration of the refrigerant leak detection system 1 having a subcooling circuit shown in Figure 1 is an example. The refrigerant leak detection system 1 may also have a configuration having an economizer circuit as shown in Figure 9. Figure 9 is a configuration diagram of an example of the refrigerant leak detection system 1 according to this embodiment. The refrigerant leak detection system 1 in Figure 9 is configured such that the subcooling heat exchanger 20 and subcooling expansion valve 22 of the refrigerant leak detection system 1 in Figure 1 are replaced with an economizer heat exchanger 40 and an economizer expansion valve 42.

[0046] Furthermore, in the refrigeration cycle device 10 shown in Figure 9, an economizer expansion valve 42 is provided in a bypass pipe connected from the piping between the indoor heat exchanger 14 and the economizer heat exchanger 40 to the middle section of the compressor 12. The economizer heat exchanger 40 is a heat exchanger that exchanges heat between the refrigerant that has passed through the economizer expansion valve 42 and the refrigerant sent from the economizer heat exchanger 40 to the outdoor expansion valve 24. Thus, the subcooling circuit shown in Figure 1 and the economizer circuit shown in Figure 9 differ in the point at which the refrigerant after depressurization is merged.

[0047] It goes without saying that the configuration of the refrigerant leak detection system 1 shown in Figure 1 can vary depending on the application and purpose.

[0048] <Hardware Configuration> The refrigerant leak detection device 30 in Figure 1 is implemented, for example, by a computer 500 with the hardware configuration shown in Figure 2.

[0049] Figure 2 is a hardware configuration diagram of an example of a computer 500 according to this embodiment. The computer 500 includes an input device 501, a display device 502, an external interface 503, RAM (Random Access Memory) 504, ROM (Read Only Memory) 505, a CPU 506, a communication interface 507, and an HDD (Hard Disk Drive) 508, and these are all interconnected via bus B. The input device 501 and the display device 502 may be connected and used only when necessary.

[0050] The input device 501 includes a touch panel, operation keys and buttons, a keyboard and mouse, etc., used by the user to input various signals. The display device 502 consists of a display such as a liquid crystal or organic EL that displays the screen, and a speaker that outputs sound data such as voice and music. The communication interface 507 is an interface for the computer 500 to communicate data via a communication network.

[0051] Furthermore, the HDD508 is an example of a non-volatile storage device that stores programs and data. The programs and data stored include the OS (Operating System), which is the basic software that controls the entire computer 500, and applications (hereinafter simply referred to as "apps") that provide various functions on the OS. Note that the computer 500 may use a drive device that uses flash memory as a storage medium (for example, a solid-state drive: SSD) instead of the HDD508.

[0052] External I / F 503 is an interface to external devices. External devices include recording media 503a. Computer 500 reads from and writes to recording media 503a via external I / F 503.

[0053] Recording media 503a include flexible disks, CDs (Compact Discs), DVDs (Digital Versatile Discs), SD (Secure Digital) memory cards, and USB (Universal Serial Bus) memory.

[0054] ROM505 is an example of non-volatile semiconductor memory (storage device) that can retain programs and data even when the power is turned off. ROM505 stores programs and data such as the BIOS (Basic Input Output System), OS settings, and network settings that are executed when the computer 500 starts up. RAM504 is an example of volatile semiconductor memory (storage device) that temporarily holds programs and data.

[0055] The CPU 506 is an arithmetic unit that controls and implements the functions of the entire computer 500 by reading programs and data from a storage device such as the ROM 505 or HDD 508 onto the RAM 504 and executing processing, and is an example of a control unit 32.

[0056] <Relationship between refrigerant amount, subcooling expansion valve, and discharge superheat> Figure 3 is a graph showing an example of the relationship between the amount of refrigerant in the refrigeration cycle device 10 and the subcooling expansion valve 22 and the discharge superheat. In the graph of Figure 3, the amount of refrigerant in the refrigeration cycle device 10 is shown on the horizontal axis. The amount of refrigerant shown on the horizontal axis of the graph of Figure 3 is based on the amount of refrigerant filled to match the amount of refrigerant required during cooling operation (100%).

[0057] The graph in Figure 3 shows the opening degree of the supercooling expansion valve 22 on the left vertical axis as an example of a value related to the supercooling expansion valve 22. The graph in Figure 3 shows the discharge superheat degree of the compressor 12 on the right vertical axis as an example of a value related to the discharge pipe temperature of the refrigeration cycle device 10.

[0058] In a refrigeration cycle system 10 equipped with a receiver 18, even if refrigerant leakage occurs from the refrigerant circuit during heating operation, the amount of refrigerant in the refrigerant circuit remains unchanged because it is replenished from the refrigerant stored in the receiver 18. The graph in Figure 3 shows an example where there is excess refrigerant in the receiver 18 until the amount of refrigerant reaches 75% of the standard. As long as there is sufficient excess refrigerant in the receiver 18, even if refrigerant leakage occurs from the refrigerant circuit, the amount that has leaked out is replenished from the refrigerant stored in the receiver 18, so the state of the refrigeration cycle does not change, and the opening degree of the subcooling expansion valve 22 and the discharge superheat of the compressor 12 do not react. As the amount of excess refrigerant in the receiver 18 approaches zero, a gas-liquid two-phase state begins at the condenser outlet, and the opening degree of the subcooling expansion valve 22 increases slightly.

[0059] Furthermore, the graph in Figure 3 shows an example where there is no excess refrigerant in the receiver 18 when the amount of refrigerant falls below 75% of the standard. In the graph in Figure 3, after there is no excess refrigerant in the receiver 18, as refrigerant leakage from the refrigerant circuit progresses, the opening degree of the subcooling expansion valve 22 reacts before the discharge superheating degree reacts.

[0060] For example, in the graph in Figure 3, when the refrigerant amount is 60% of the standard, it can be determined that the behavior of the opening degree of the subcooling expansion valve 22 is different from when there is excess refrigerant in the receiver 18, and refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 can be detected. Alternatively, in the graph in Figure 3, when the refrigerant amount is, for example, 75-60% of the standard, it may be determined that the behavior of the opening degree of the subcooling expansion valve 22 is different from when there is excess refrigerant in the receiver 18, and refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 can be detected.

[0061] Furthermore, in the graph shown in Figure 3, when the refrigerant amount is 50% of the standard, it is determined that the behavior of the discharge superheating degree differs from that when there is excess refrigerant in the receiver 18, and refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 can be detected.

[0062] As shown by arrow 1000 in the graph of Figure 3, detecting refrigerant leakage based on the reaction of the opening degree of the subcooling expansion valve 22 allows for earlier detection of refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 than detecting refrigerant leakage based on the reaction of the discharge superheat.

[0063] Furthermore, as shown in the graph in Figure 3, the opening of the subcooling expansion valve 22 becomes fixed at 100% when the refrigerant amount falls below 50% of the standard. On the other hand, even when the refrigerant amount falls below 50% of the standard, the discharge superheat continues to rise. Therefore, when detecting refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 after the refrigerant amount falls below 50% of the standard, it is desirable to detect refrigerant leakage by the reaction of the discharge superheat.

[0064] For example, in the refrigerant circuit of the refrigeration cycle device 10, when the amount of refrigerant becomes insufficient, the degree of subcooling (also called subcool or SC) decreases, and the opening of the subcooling expansion valve 22 remains large to increase the amount of refrigerant flowing through the subcooling expansion valve 22. If the amount of refrigerant becomes even more insufficient and the subcooling expansion valve 22 opens completely, the opening of the outdoor expansion valve 24 in the refrigeration circuit of the refrigeration cycle device 10 increases, and when the outdoor expansion valve 24 is fully open, the discharge superheat continues to rise.

[0065] Therefore, the refrigerant leak detection device 30 according to this embodiment can detect refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 based on values ​​related to the subcooling expansion valve 22 or the economizer expansion valve 42, and can also detect refrigerant leakage based on values ​​related to the discharge pipe temperature when the amount of refrigerant in the refrigerant circuit decreases. Note that the values ​​related to the subcooling expansion valve 22 or the economizer expansion valve 42 are synonymous with the values ​​related to the subcooling expansion valve 22 or the economizer expansion valve 42.

[0066] <Processing> The refrigerant leak detection device 30 according to this embodiment performs the following learning phase before the detection phase in which it detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10. Here, an example is described in which the refrigeration cycle device 10 performs the learning phase processing, but a learning device other than the refrigeration cycle device 10 may also perform the learning phase processing.

[0067] Figure 4 is a flowchart of an example of a learning phase.

[0068] In step S10, the control unit 32 of the refrigerant leak detection device 30 acquires operating data of the refrigeration cycle device 10 under normal conditions as learning data. The operating data of the refrigeration cycle device 10 under normal conditions is past operating data acquired from a refrigeration cycle device 10 that is functioning normally and has not experienced any refrigerant leaks or equipment malfunctions.

[0069] The operating data of the refrigeration cycle device 10 obtained in step S10 should include data for machine learning a first normal prediction model that outputs normal predicted values ​​for the subcooling expansion valve 22 or the economizer expansion valve 42, and a second normal prediction model that outputs normal predicted values ​​for the discharge pipe temperature.

[0070] For example, the operating data acquired as training data may include the rotational speed of the compressor 12, the rotational speed of the fan, the opening degree of the subcooling expansion valve 22 or the economizer expansion valve 42, the discharge pipe temperature of the compressor 12, the discharge superheating degree, and the ambient temperature.

[0071] In step S12, the control unit 32 uses the normal operating data of the refrigeration cycle device 10 acquired in step S10 as training data to create a first normal prediction model by machine learning that outputs normal predicted values ​​for the subcooling expansion valve 22 or the economizer expansion valve 42. The control unit 32 may also machine learn the first normal prediction model using the opening degree of the subcooling expansion valve 22 or the economizer expansion valve 42 included in the training data as the target variable, and the rotational speed of the compressor 12, the ambient temperature, etc. as explanatory variables. In addition, the value for the subcooling expansion valve 22 may be the refrigerant flow rate ratio, CV value, or a cooling capacity value converted from the opening degree of the subcooling expansion valve 22, in addition to the opening degree of the subcooling expansion valve 22. The CV value is a coefficient that indicates the ease of fluid flow. The value for the economizer expansion valve 42 may be the refrigerant flow rate ratio, CV value, or a cooling capacity value converted from the opening degree of the economizer expansion valve 42, in addition to the opening degree of the economizer expansion valve 42.

[0072] In step S14, the control unit 32 uses the normal operating data of the refrigeration cycle device 10 acquired in step S10 as training data to create a second normal prediction model by machine learning that outputs a normal predicted value for the discharge pipe temperature. The control unit 32 may also machine learn the second normal prediction model using the discharge superheat of the compressor 12 included in the training data as the target variable and the rotational speed of the compressor 12, ambient temperature, etc. as explanatory variables. The discharge superheat of the compressor 12 is calculated based on the discharge pipe temperature of the compressor 12 and the condensation temperature of the condenser. In addition to the discharge superheat of the compressor 12, the value related to the discharge pipe temperature may also be the discharge pipe temperature of the compressor 12.

[0073] According to the learning phase shown in Figure 4, a first normal prediction model that outputs normal predicted values ​​for the subcooling expansion valve 22 or economizer expansion valve 42, and a second normal prediction model that outputs normal predicted values ​​for the discharge pipe temperature can be generated from the operating data of the refrigeration cycle device 10. Note that the order of processing in steps S12 and S14 may be reversed.

[0074] The refrigerant leak detection device 30 according to this embodiment uses the first normal prediction model 100 and the second normal prediction model 102 generated in the learning phase shown in Figure 4 to detect refrigerant leaks from the refrigerant circuit of the refrigeration cycle device 10, which is the target device for refrigerant leak detection.

[0075] Figure 5 is a flowchart of an example of the detection phase. Figures 6 to 8 are explanatory diagrams of an example of the processing in the detection phase.

[0076] In step S30, the control unit 32 of the refrigerant leak detection device 30 acquires operating data of the refrigeration cycle device 10 of the target machine for which refrigerant leakage from the refrigerant circuit is detected. In step S30, the operating data of the refrigeration cycle device 10 of the target machine may be acquired in real time, or it may be acquired in batches for a predetermined period.

[0077] In step S32, the control unit 32 outputs a normal prediction value for the subcooling expansion valve 22 or economizer expansion valve 42, which is the operating data of the refrigeration cycle device 10 of the detection target machine acquired in the processing of step S30, using the first normal prediction model 100 generated in the learning phase.

[0078] In step S34, the control unit 32 obtains measured values ​​related to the subcooling expansion valve 22 or the economizer expansion valve 42 from the operating data of the refrigeration cycle device 10 of the detection target machine acquired in the processing of step S30.

[0079] In step S36, the control unit 32 calculates the difference Δ value for the subcooled expansion valve 22 or the economizer expansion valve 42, as shown in Figure 6, between the normal predicted value for the subcooled expansion valve 22 or the economizer expansion valve 42 output in the processing of step S32 and the measured value for the subcooled expansion valve 22 or the economizer expansion valve 42 obtained in the processing of step S34. The difference Δ value for the subcooled expansion valve 22 or the economizer expansion valve 42 will be a value as shown in Figure 7(B), and will tend to increase after refrigerant leakage occurs from the refrigerant circuit of the refrigeration cycle device 10.

[0080] Furthermore, in step S38, the control unit 32 outputs a normal prediction value for the discharge pipe temperature, which is the operating data of the refrigeration cycle device 10 of the detection target machine acquired in the processing of step S30, using the second normal prediction model 102 generated in the learning phase.

[0081] In step S40, the control unit 32 obtains measured values ​​related to the discharge pipe temperature from the operating data of the refrigeration cycle device 10 of the machine to be detected, which was obtained in the processing of step S30.

[0082] In step S42, the control unit 32 calculates the difference Δ value for discharge pipe temperature between the normal predicted value for discharge pipe temperature output in step S38 and the measured value for discharge pipe temperature obtained in step S40, as shown in Figure 6.

[0083] In step S44, the control unit 32 determines whether the difference Δ value related to the subcooling expansion valve 22 or the Δ value related to the economizer expansion valve 42, calculated in the processing of step S36, exceeds a threshold. The threshold should be set to a value that does not falsely detect refrigerant leakage.

[0084] If the control unit 32 determines that the value related to the differential Δ subcooling expansion valve 22 or the value related to the Δ economizer expansion valve 42 calculated in step S36 exceeds a threshold, it proceeds to step S48. For example, as shown in Figure 7(B), if the control unit 32 determines that the value related to the differential Δ subcooling expansion valve 22 or the value related to the Δ economizer expansion valve 42 exceeds a threshold, it proceeds to step S48.

[0085] In step S48, the control unit 32 detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 of the target machine. Thus, as shown in Figure 7(B), for example, the control unit 32 can detect refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 of the target machine when the value related to the differential Δ subcooling expansion valve 22 or the value related to the Δ economizer expansion valve 42 exceeds a threshold.

[0086] Furthermore, in step S44, if the control unit 32 determines that the value related to the difference Δ discharge pipe temperature calculated in step S42 exceeds a threshold, it proceeds to step S48. For example, if the control unit 32 determines that the value related to the difference Δ discharge pipe temperature exceeds a threshold, it proceeds to step S48.

[0087] In step S48, the control unit 32 detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 of the target machine. In this way, the control unit 32 can detect refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 of the target machine, for example, when the value related to the differential Δ discharge pipe temperature exceeds a threshold.

[0088] After the processing in step S48, the control unit 32 issues an alert to the user (such as a service technician) associated with the refrigeration cycle device 10 of the detected machine. The alert to the user associated with the refrigeration cycle device 10 of the detected machine can be issued using existing technology that enables notification to the user.

[0089] In step S46, if the control unit 32 determines that the difference Δ value related to the discharge pipe temperature calculated in step S42 does not exceed the threshold, it determines that there is no refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 of the detected machine, and terminates the processing of the flowchart in Figure 5.

[0090] The flowchart in Figure 5 processes, for example, as shown in the table in Figure 8, if it is determined that refrigerant leakage has occurred based on either the value related to the differential Δ subcooling expansion valve 22 or the value related to the Δ economizer expansion valve 42, or the value related to the differential Δ discharge pipe temperature, it is determined that refrigerant leakage has occurred from the refrigerant circuit of the refrigeration cycle device 10 of the detected machine.

[0091] As described above, the refrigerant leak detection system 1 according to this embodiment can detect refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 equipped with the receiver 18 at an earlier stage using the difference Δ value related to the subcooling expansion valve 22 or the Δ value related to the economizer expansion valve 42, and can also detect further refrigerant leakage using the difference Δ value related to the discharge pipe temperature.

[0092] According to the refrigerant leak detection system 1 of this embodiment, it is possible to provide a refrigerant leak detection device 30, a refrigerant leak detection method, and a refrigerant leak detection system 1 that can detect refrigerant leaks from the refrigerant circuit of the refrigeration cycle device 10 more quickly.

[0093] [Effect] This embodiment is a refrigerant leak detection device having a control unit, the control unit acquires operating data of the refrigeration cycle device, and detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle device based on values ​​related to the subcooling expansion valve or economizer expansion valve and values ​​related to the discharge pipe temperature of the refrigeration cycle device included in the operating data. The control unit is, for example, the control unit 32 of the refrigerant leak detection device 30.

[0094] In this embodiment, refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 is detected based on values ​​related to the subcooling expansion valve 22 or economizer expansion valve 42 and values ​​related to the discharge pipe temperature of the refrigeration cycle device 10. By using values ​​related to the subcooling expansion valve 22 or economizer expansion valve 42 to detect refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10, a refrigerant leakage detection device 30 that can detect refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 more quickly can be provided. The refrigeration cycle device 10 may also include a receiver 18 for storing excess refrigerant.

[0095] Furthermore, by using a value related to the discharge pipe temperature of the refrigeration cycle device 10 to detect refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10, a refrigerant leakage detection device 30 can be provided that can detect refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 even at amounts that cannot be detected by refrigerant leakage detection using values ​​related to the subcooling expansion valve 22 or the economizer expansion valve 42. The refrigeration cycle device 10 may also be equipped with a receiver 18 for storing excess refrigerant.

[0096] Furthermore, the control unit uses a first normal prediction model, which is based on machine learning of the operating data of the refrigeration cycle system under normal conditions, to output a normal prediction value for the subcooled expansion valve or economizer expansion valve. Based on this normal prediction value and the actual measured value of the subcooled expansion valve or economizer expansion valve included in the operating data, the control unit detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle system.

[0097] In this embodiment, a first normal prediction model 100, which is based on machine learning of the operating data of the refrigeration cycle device 10 under normal conditions, is used to output a normal prediction value for the subcooling expansion valve 22 or economizer expansion valve 42. By detecting refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 based on the normal prediction value for the subcooling expansion valve 22 or economizer expansion valve 42 and the measured value for the subcooling expansion valve 22 or economizer expansion valve 42 included in the operating data, the occurrence of refrigerant leakage can be detected with greater accuracy. For example, refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 may be detected based on the difference between the measured value and the normal prediction value. Alternatively, refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 may be detected based on (measured value) / (normal prediction value). Alternatively, refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 may be detected based on (measured value - normal prediction value) / (normal prediction value).

[0098] Furthermore, the control unit uses a second normal prediction model for the discharge pipe temperature of the refrigeration cycle, which is based on machine learning of the operating data of the refrigeration cycle during normal operation, to output a normal predicted value for the discharge pipe temperature of the refrigeration cycle. Based on the normal predicted value for the discharge pipe temperature of the refrigeration cycle and the measured value for the discharge pipe temperature of the refrigeration cycle, the control unit detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle.

[0099] In this embodiment, a second normal prediction model 102, which is based on machine learning of the operating data of the refrigeration cycle device 10 under normal conditions, is used to output a normal prediction value for the discharge pipe temperature. By detecting refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 based on the normal prediction value for the discharge pipe temperature and the measured value for the discharge pipe temperature included in the operating data, the occurrence of refrigerant leakage can be detected with greater accuracy. For example, refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 may be detected based on the difference between the measured value and the normal prediction value. Alternatively, refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 may be detected based on (measured value) / (normal prediction value). Alternatively, refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 may be detected based on (measured value - normal prediction value) / (normal prediction value).

[0100] Furthermore, the control unit detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle system if at least one of the following results indicates refrigerant leakage: the result of detecting refrigerant leakage from the refrigerant circuit of the refrigeration cycle system based on values ​​related to the subcooling expansion valve or economizer expansion valve included in the operating data, and the result of detecting refrigerant leakage from the refrigerant circuit of the refrigeration cycle system based on values ​​related to the discharge pipe temperature of the refrigeration cycle system.

[0101] According to this embodiment, if at least one of the results of detecting refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 based on values ​​related to the subcooling expansion valve 22 or economizer expansion valve 42 included in the operating data, and the results of detecting refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 based on values ​​related to the discharge pipe temperature of the refrigeration cycle device 10, then the occurrence of refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 can be detected. Therefore, in this embodiment, the occurrence of refrigerant leakage can be detected with greater accuracy.

[0102] Furthermore, if the control unit detects a refrigerant leak from the refrigerant circuit of the refrigeration cycle system, it will issue an alert to the user associated with the refrigeration cycle system.

[0103] According to this embodiment, when a refrigerant leak from the refrigerant circuit of the refrigeration cycle device 10 is detected, an alert can be automatically sent to a user such as a service technician connected to the refrigeration cycle device 10.

[0104] Furthermore, the values ​​related to the subcooling expansion valve are the opening degree of the subcooling expansion valve, the refrigerant flow rate ratio, the CV value, or the cooling capacity value calculated from the opening degree of the subcooling expansion valve.

[0105] According to this embodiment, the opening degree of the subcooling expansion valve 22, the refrigerant flow rate ratio, the CV value, or the cooling capacity value calculated from the opening degree of the subcooling expansion valve 22 can be used as values ​​related to the subcooling expansion valve 22.

[0106] Furthermore, the values ​​related to the economizer expansion valve are the opening degree of the economizer expansion valve, the refrigerant flow rate ratio, the CV value, or the cooling capacity value calculated from the opening degree of the economizer expansion valve.

[0107] According to this embodiment, the opening degree of the economizer expansion valve 42, the refrigerant flow rate ratio, the CV value, or the cooling capacity value calculated from the opening degree of the economizer expansion valve 42 can be used as values ​​related to the economizer expansion valve 42.

[0108] Furthermore, the value relating to the discharge pipe temperature of the refrigeration cycle system is the discharge pipe temperature of the compressor of the refrigeration cycle system, or the compressor discharge superheating degree calculated based on the discharge pipe temperature of the compressor of the refrigeration cycle system and the condensation temperature of the condenser.

[0109] According to this embodiment, the discharge pipe temperature of the compressor 12 of the refrigeration cycle device 10, or the discharge superheat of the compressor 12 calculated based on the discharge pipe temperature of the compressor 12 of the refrigeration cycle device 10 and the condensation temperature of the indoor heat exchanger 14 (condenser), can be used as a value related to the discharge pipe temperature of the refrigeration cycle device 10.

[0110] Furthermore, this embodiment is a refrigerant leak detection method performed by a refrigerant leak detection device having a control unit, wherein the control unit acquires operating data of the refrigeration cycle device and detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle device based on values ​​related to the subcooling expansion valve or economizer expansion valve and values ​​related to the discharge pipe temperature of the refrigeration cycle device included in the operating data.

[0111] According to this embodiment, a refrigerant leak detection method can be provided that can detect refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 more quickly. The refrigeration cycle device 10 may also include a receiver 18 for storing excess refrigerant.

[0112] Furthermore, this embodiment is a refrigerant leak detection system comprising a refrigeration cycle device and an information processing device having a control unit, wherein the control unit acquires operating data of the refrigeration cycle device and detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle device based on values ​​related to the subcooling expansion valve or economizer expansion valve and values ​​related to the discharge pipe temperature of the refrigeration cycle device included in the operating data.

[0113] According to this embodiment, a refrigerant leak detection system 1 can be provided that can detect refrigerant leakage from the refrigerant circuit of the refrigeration cycle device 10 more quickly. The refrigeration cycle device 10 may also include a receiver 18 for storing excess refrigerant.

[0114] As described above, this embodiment can be understood to be capable of various modifications to its form and details without departing from the spirit and scope of the claims. [Explanation of Symbols]

[0115] 1. Refrigerant leak detection system 10 Refrigeration cycle equipment 12 Compressor 18 Receivers 20 Subcooling heat exchanger 22 Supercooled Expansion Valve 30 Refrigerant leak detection device 32 Control Unit 40 Economizer Heat Exchanger 42 Economizer Expansion Valve

Claims

1. A refrigerant leak detection device having a control unit, The control unit, We acquire operating data for the refrigeration cycle system. Based on the values ​​related to the subcooling expansion valve or economizer expansion valve included in the aforementioned operating data and the values ​​related to the discharge pipe temperature of the refrigeration cycle device, refrigerant leakage from the refrigerant circuit of the refrigeration cycle device is detected. Refrigerant leak detection device.

2. The control unit outputs normal predicted values ​​for the supercooling expansion valve or the economizer expansion valve using a first normal prediction model that has been trained on the operating data of the refrigeration cycle system under normal conditions. Based on the normal predicted values ​​for the subcooling expansion valve or the economizer expansion valve and the measured values ​​for the subcooling expansion valve or economizer expansion valve included in the operating data, refrigerant leakage from the refrigerant circuit of the refrigeration cycle system is detected. The refrigerant leak detection device according to claim 1.

3. The control unit outputs a normal predicted value for the discharge pipe temperature of the refrigeration cycle using a second normal prediction model that has been trained on the operating data of the refrigeration cycle during normal operation. Based on the normal predicted value for the discharge pipe temperature of the refrigeration cycle device and the measured value for the discharge pipe temperature of the refrigeration cycle device, refrigerant leakage from the refrigerant circuit of the refrigeration cycle device is detected. The refrigerant leak detection device according to claim 2.

4. The control unit detects refrigerant leakage from the refrigerant circuit of the refrigeration cycle if at least one of the results of detecting refrigerant leakage from the refrigerant circuit of the refrigeration cycle based on values ​​related to the subcooling expansion valve or economizer expansion valve included in the operating data, and the results of detecting refrigerant leakage from the refrigerant circuit of the refrigeration cycle based on values ​​related to the discharge pipe temperature of the refrigeration cycle, indicates that refrigerant leakage is present. The refrigerant leak detection device according to claim 1.

5. When the control unit detects a refrigerant leak from the refrigerant circuit of the refrigeration cycle device, it issues an alert to the user associated with the refrigeration cycle device. A refrigerant leak detection device according to any one of claims 1 to 4.

6. The values ​​relating to the subcooling expansion valve are the opening degree of the subcooling expansion valve, the refrigerant flow rate ratio, the CV value, or the cooling capacity value calculated from the opening degree of the subcooling expansion valve. A refrigerant leak detection device according to any one of claims 1 to 4.

7. The values ​​relating to the economizer expansion valve are the opening degree of the economizer expansion valve, the refrigerant flow rate ratio, the CV value, or the cooling capacity value calculated from the opening degree of the economizer expansion valve. A refrigerant leak detection device according to any one of claims 1 to 4.

8. The value relating to the discharge pipe temperature of the refrigeration cycle device is the discharge pipe temperature of the compressor of the refrigeration cycle device, or the discharge superheating degree of the compressor calculated based on the discharge pipe temperature of the compressor of the refrigeration cycle device and the condensation temperature of the condenser. A refrigerant leak detection device according to any one of claims 1 to 4.

9. A refrigerant leak detection method performed by a refrigerant leak detection device having a control unit, The control unit, We acquire operating data for the refrigeration cycle system. Based on the values ​​related to the subcooling expansion valve or economizer expansion valve included in the aforementioned operating data and the values ​​related to the discharge pipe temperature of the refrigeration cycle device, refrigerant leakage from the refrigerant circuit of the refrigeration cycle device is detected. Refrigerant leak detection method.

10. A refrigerant leak detection system comprising a refrigeration cycle device and an information processing device having a control unit, The control unit, The operating data of the aforementioned refrigeration cycle device is acquired, Based on the values ​​related to the subcooling expansion valve or economizer expansion valve included in the aforementioned operating data and the values ​​related to the discharge pipe temperature of the refrigeration cycle device, refrigerant leakage from the refrigerant circuit of the refrigeration cycle device is detected. Refrigerant leak detection system.

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