Refrigerant leak location estimation device, refrigerant leak location estimation method, and refrigeration and air conditioning system

Abstract

This refrigerant leak location estimation device comprises a control unit, wherein the control unit: assess for refrigerant leak from a refrigeration and air conditioning apparatus on the basis of a change in a refrigerant quantity index calculated from operation data of the refrigeration and air conditioning apparatus; estimates a refrigerant leak rate during refrigerant leak from the refrigeration and air conditioning apparatus; and uses information, in which the relationships between the refrigerant leak rate in refrigerant leaks that have occurred in the past and refrigerant leak locations are recorded, to estimate one or more refrigerant leak locations from the estimated refrigerant leak rate during the refrigerant leak.

Description

Refrigerant Leak Location Estimation Device, Refrigerant Leak Location Estimation Method, and Refrigeration and Air Conditioning System

[0001] The present disclosure relates to a refrigerant leak location estimation device, a refrigerant leak location estimation method, and a refrigeration and air conditioning system.

[0002] A refrigerant leak detection system that calculates from the operation data of refrigeration and air conditioning equipment and detects a loss (refrigerant leakage) of the refrigerant filling amount of the refrigeration and air conditioning equipment based on a value (refrigerant amount index) that is an index of the refrigerant amount filled in the refrigeration and air conditioning equipment has been conventionally known (see, for example, Patent Document 1).

[0003] Japanese Patent Publication No. 2018-533718

[0004] When refrigerant leakage is detected by a conventional refrigerant leak detection system or a regular inspection by a service technician, the repair worker searches for the refrigerant leakage location and refills the refrigerant after repairing the refrigerant leakage location. However, since a method for specifying the refrigerant leakage location has not been established, the search for the refrigerant leakage location is carried out haphazardly, for example, according to the order described manually for places where leakage may occur or the order based on the experience of the repair worker. For this reason, conventionally, it has taken a long time to identify the refrigerant leakage location. When there are many places where refrigerant leakage may occur, such as in a multi-air conditioner for a building, it has taken even more time to identify the refrigerant leakage location.

[0005] An object of the present disclosure is to provide a refrigerant leak location estimation device, a refrigerant leak location estimation method, and a refrigeration and air conditioning system that reduce the time until a repair worker identifies the refrigerant leak location.

[0006] A first aspect of the present disclosure is a refrigerant leak location estimation device having a control unit, wherein the control unit determines refrigerant leakage of the refrigeration and air conditioning equipment based on a change in a refrigerant amount index calculated from the operation data of the refrigeration and air conditioning equipment, estimates the refrigerant leakage rate at the time of refrigerant leakage of the refrigeration and air conditioning equipment, and uses information in which the relationship between the refrigerant leakage rate and the refrigerant leak location in past refrigerant leakages is recorded to estimate one or more refrigerant leak locations from the estimated refrigerant leakage rate at the time of refrigerant leakage.

[0007] According to the first aspect of the present disclosure, a refrigerant leak location estimation device that reduces the time until a repair worker identifies the refrigerant leak location can be provided.

[0008] A second aspect of the present disclosure is a refrigerant leak location estimation device according to the first aspect, wherein the control unit estimates one or more refrigerant leak locations from the estimated refrigerant leak rate at the time of the refrigerant leak, using historical information which records the relationship between the attributes of the refrigeration and air conditioning equipment and the refrigerant leak location, in addition to the refrigerant leak rate in past refrigerant leaks.

[0009] According to a second aspect of this disclosure, one or more refrigerant leak locations can be estimated using historical information that records the relationship between the refrigerant leak rate in past refrigerant leaks, as well as the attributes of one or more refrigeration and air conditioning equipment and the location of the refrigerant leak.

[0010] A third aspect of this disclosure is a refrigerant leak location estimation device according to the second aspect, wherein the control unit estimates one or more refrigerant leak locations from the estimated refrigerant leak rate at the time of the refrigerant leak using a predictive model trained on the historical information.

[0011] According to a third aspect of this disclosure, one or more refrigerant leak locations can be estimated from the estimated refrigerant leak rate at the time of refrigerant leakage using a predictive model trained on historical information.

[0012] A fourth aspect of the present disclosure is a refrigerant leak location estimation device according to the second aspect, wherein the control unit estimates one or more refrigerant leak locations from the estimated refrigerant leak rate at the time of the leak, using the historical information which is further limited to a specific range among the attributes relating to one or more of the refrigeration and air conditioning equipment.

[0013] According to a fourth aspect of this disclosure, using the historical information, which is further limited to a specific range among the attributes relating to one or more refrigeration and air conditioning devices, one or more refrigerant leakage locations can be estimated from the estimated refrigerant leakage rate at the time of refrigerant leakage.

[0014] A fifth aspect of the present disclosure is a refrigerant leak location estimation device according to the second aspect, wherein the control unit uses historical information that records the relationship between the refrigerant leak rate and the refrigerant leak location in past refrigerant leaks to estimate one or more candidate refrigerant leak locations from the estimated refrigerant leak rate at the time of the refrigerant leak, and further uses historical information that records the relationship between the attribute of one or more refrigeration and air conditioning equipment and the refrigerant leak location to select one or more candidate refrigerant leak locations from the estimated candidate refrigerant leak locations.

[0015] According to a fifth aspect of this disclosure, one or more refrigerant leakage locations can be estimated from the estimated refrigerant leakage rate at the time of refrigerant leakage, and one or more refrigerant leakage location candidates can be selected from the estimated refrigerant leakage location candidates using historical information that records the relationship between one or more attributes of the refrigeration and air conditioning equipment and the refrigerant leakage locations.

[0016] A sixth aspect of this disclosure is a refrigerant leak location estimation device according to the second aspect, wherein the attribute relating to the refrigeration and air conditioning equipment is the number of years installed, location, intended use, or model of the refrigeration and air conditioning equipment.

[0017] According to a sixth aspect of this disclosure, the number of years installed, location, intended use, or model of the refrigeration and air conditioning equipment can be used as attributes relating to the refrigeration and air conditioning equipment.

[0018] A seventh aspect of this disclosure is a refrigerant leak location estimation device according to any one of the first to sixth aspects, wherein the control unit notifies a repair worker associated with the refrigeration and air conditioning equipment that determined the refrigerant leak of the one or more estimated refrigerant leak locations.

[0019] According to a seventh aspect of this disclosure, one or more estimated refrigerant leak locations can be notified to the repair worker associated with the refrigeration and air conditioning equipment that detected the refrigerant leak.

[0020] An eighth aspect of the present disclosure is a refrigerant leak location estimation device according to any one of the first to seventh aspects, wherein the control unit estimates the indoor unit, outdoor unit, or on-site piping of the refrigeration and air conditioning equipment as the refrigerant leak location.

[0021] According to the eighth aspect of this disclosure, the indoor unit, outdoor unit, or on-site piping of a refrigeration and air conditioning system can be estimated as the location of a refrigerant leak.

[0022] A ninth aspect of the present disclosure is a method for estimating a refrigerant leak location performed by a refrigerant leak location estimation device having a control unit, wherein the control unit determines refrigerant leakage of the refrigeration and air conditioning equipment based on changes in a refrigerant quantity index calculated from operating data of the refrigeration and air conditioning equipment, estimates the refrigerant leakage rate at the time of refrigeration leakage of the refrigeration and air conditioning equipment, and estimates one or more refrigerant leak locations from the estimated refrigerant leakage rate at the time of refrigerant leakage using information recorded in relation to the relationship between the refrigerant leakage rate and the refrigerant leak location in past refrigerant leaks.

[0023] According to a ninth aspect of this disclosure, a method for estimating the location of a refrigerant leak can be provided that reduces the time it takes for a repair worker to identify the location of the refrigerant leak.

[0024] A tenth aspect of the present disclosure is a refrigeration and air conditioning system comprising a refrigeration and air conditioning device and an information processing device having a control unit, wherein the control unit determines refrigerant leakage of the refrigeration and air conditioning device based on changes in a refrigerant quantity index calculated from operating data of the refrigeration and air conditioning device, estimates the refrigerant leakage rate at the time of refrigerant leakage of the refrigeration and air conditioning device, and estimates one or more refrigerant leakage locations from the estimated refrigerant leakage rate at the time of refrigerant leakage using information recorded in which the relationship between the refrigerant leakage rate and the location of refrigerant leakage in past refrigerant leaks is recorded.

[0025] According to a tenth aspect of this disclosure, a refrigeration and air conditioning system can be provided that reduces the time it takes for repair workers to identify the location of a refrigerant leak.

[0026] This is a diagram showing the configuration of an example of a refrigeration and air conditioning system 1 according to this embodiment. This is a hardware configuration diagram of an example of a computer 500 according to this embodiment. This is a graph showing an example of a process for calculating the refrigerant leakage rate from a refrigerant quantity index. This is a graph showing an example of a process for calculating the refrigerant leakage rate from a refrigerant quantity index. This is a graph showing an example of a refrigerant leakage rate distribution. This is a flowchart showing an example of a process of the refrigerant leakage location estimation device 30 according to this embodiment. This is a flowchart showing an example of a process in step S18. This is a flowchart showing an example of a process in step S18.

[0027] Next, embodiments of this disclosure will be described in detail.

[0028] <System Configuration> Figure 1 is a configuration diagram of an example of a refrigeration and air conditioning system 1 according to this embodiment. The refrigeration and air conditioning system 1 in Figure 1 has refrigeration and air conditioning equipment 10 and a refrigerant leak location estimation device 30. The refrigeration and air conditioning equipment 10 is a refrigeration and air conditioning system consisting of a condensing unit and a showcase, a household hot water supply and heating system, a multi-split air conditioner for buildings, an air conditioner for shops, an air conditioner for offices, or a room air conditioner, etc.

[0029] The refrigeration and air conditioning equipment 10 in Figure 1 consists of an outdoor unit 12, one or more indoor units 14, and on-site piping 16. The outdoor unit 12 shown in Figure 1 includes a compressor 20, an outdoor heat exchanger 21, a subcooling heat exchanger 22, an accumulator 23, a four-way switching valve 24, and internal outdoor unit piping 25. The indoor unit 14 includes an indoor heat exchanger 26.

[0030] The outdoor unit 12 and indoor unit 14 of the refrigeration and air conditioning equipment 10 are connected by local piping 16 through which the refrigerant flows, forming a refrigerant circuit. In the refrigeration and air conditioning equipment 10 shown in Figure 1, a four-way switching valve 24 reverses the flow of refrigerant circulating in the refrigerant circuit between cooling operation and heating operation. The compressor 20, outdoor heat exchanger 21, subcooling heat exchanger 22, accumulator 23, and four-way switching valve 24 are connected by piping 25 inside the outdoor unit to form a refrigerant circuit.

[0031] The compressor 20 compresses the refrigerant to high pressure. The outdoor heat exchanger 21 performs heat exchange between the outside air and the refrigerant passing through its interior. The subcooled heat exchanger 22 performs heat exchange between the refrigerant that has passed through the subcooled expansion valve and the refrigerant that has passed through the interior of the subcooled heat exchanger 22.

[0032] The accumulator 23 functions as a buffer tank that stores excess liquid refrigerant when it flows in, thereby preventing liquid compression in the compressor 20.

[0033] Furthermore, the indoor heat exchanger 26 of one or more indoor units 14 performs heat exchange between indoor air and refrigerant passing through it. In addition, the indoor unit 14 is equipped with a fan (not shown), and the action of the fan promotes the heat exchange between indoor air and refrigerant in the indoor heat exchanger 26.

[0034] The refrigeration and air conditioning equipment 10 is equipped with various sensors on the outdoor unit 12 and the indoor unit 14. The various sensors provided on the outdoor unit 12 and the indoor unit 14 are used, for example, for controlling the refrigeration and air conditioning equipment 10. The various sensors provided on the outdoor unit 12 and the indoor unit 14 include temperature sensors, pressure sensors, and current sensors. A temperature sensor is, for example, a thermistor.

[0035] Furthermore, the refrigerant leak location estimation device 30 estimates the refrigerant leakage rate when refrigerant leaks from the refrigeration and air conditioning equipment 10. The refrigerant leak location estimation device 30 uses information recorded on the relationship between refrigerant leakage rate and refrigerant leak location in past refrigerant leaks to estimate one or more refrigerant leak locations from the refrigerant leakage rate at the time of the refrigerant leak. The information recorded on the relationship between refrigerant leakage rate and refrigerant leak location in past refrigerant leaks is, for example, historical information recorded on the relationship between refrigerant leakage rate and refrigerant leak location in past refrigerant leaks.

[0036] The refrigerant leak location estimation 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 to estimate the location of refrigerant leaks from the refrigerant circuit of the refrigeration and air conditioning equipment 10.

[0037] For example, the refrigerant leak location estimation device 30 acquires the data described later from the refrigeration and air conditioning equipment 10 necessary to estimate the location of the refrigerant leak from the refrigerant circuit. The refrigerant leak location estimation device 30 may also acquire the data described later from a device other than the refrigeration and air conditioning equipment 10 that stores the data necessary to estimate the location of the refrigerant leak from the refrigerant circuit. Details of the processing of the refrigerant leak location estimation device 30 will be described later.

[0038] The refrigerant leak location estimation device 30 has a control unit 32. The control unit 32 is a hardware configuration that executes a program. The control unit 32 is a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field Programmable Gate Array), etc. For example, the refrigerant leak location estimation device 30 can perform various processes described later by having a CPU, one example of the control unit 32, execute a program.

[0039] The configuration of the refrigeration and air conditioning system 1 shown in Figure 1 is an example. The refrigerant leak location estimation device 30 may be implemented using one or more information processing devices. Alternatively, the refrigerant leak location estimation device 30 may be implemented as a cloud computing service.

[0040] In Figure 1, the control unit 32 of the refrigerant leak location estimation device 30 is shown as an example, but the refrigeration and air conditioning equipment 10 may also have a control unit. The various processes performed by the control unit 32 of the refrigerant leak location estimation device 30, as described later, may also be performed by the control unit of the refrigeration and air conditioning equipment 10. The various processes performed by the control unit 32 of the refrigerant leak location estimation device 30 may also be performed in cooperation with the control unit of the refrigeration and air conditioning equipment 10.

[0041] It goes without saying that the configuration of the refrigeration and air conditioning system 1 shown in Figure 1 can vary depending on the application and purpose.

[0042] <Hardware Configuration> The refrigerant leak location estimation device 30 shown in Figure 1 is implemented, for example, by a computer 500 with the hardware configuration shown in Figure 2.

[0043] 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.

[0044] Input device 501 includes a touch panel, operation keys, buttons, a keyboard, a mouse, etc., which are used by repair workers to input various signals. Display device 502 is composed of a display such as a liquid crystal or an organic EL for displaying a screen, a speaker for outputting sound data such as voice and notification sounds, etc. Communication I / F 507 is an interface for computer 500 to perform data communication via a communication network.

[0045] Further, HDD 508 is an example of a non-volatile storage device that stores programs and data. The stored programs and data include an OS (Operating System), which is basic software for controlling the entire computer 500, and applications (hereinafter simply referred to as apps) that provide various functions on the OS. Note that computer 500 may use a drive device (for example, a solid state drive: SSD, etc.) that uses a flash memory as a storage medium instead of HDD 508.

[0046] External I / F 503 is an interface with an external device. Examples of the external device include a recording medium 503a, etc. Computer 500 reads and writes to recording medium 503a via external I / F 503.

[0047] Recording medium 503a is a flexible disk, a CD (Compact Disc), a DVD (Digital Versatile Disc), an SD (Secure Digital) memory card, a USB (Universal Serial Bus) memory, etc.

[0048] ROM 505 is an example of a non-volatile semiconductor memory (storage device) that can retain programs and data even when the power is turned off. ROM 505 stores programs and data such as the BIOS (Basic Input Output System), OS settings, and network settings that are executed when computer 500 starts up. RAM 504 is an example of a volatile semiconductor memory (storage device) that temporarily holds programs and data.

[0049] 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.

[0050] <Relationship between refrigerant leak location and leakage amount> The relationship between the refrigerant leak location and the refrigerant leakage rate can be determined, for example, by analyzing historical information such as repair records for past refrigerant leaks. The refrigerant leakage rate can be calculated, for example, from the slope of the refrigerant quantity index obtained by dividing the difference (change) between the refrigerant leak index at the time of detection and the refrigerant quantity index at a certain time (ΔT) prior to the detection time by ΔT, and from the conversion coefficient between the refrigerant quantity index and the actual refrigerant quantity. The past time may also be the time of the inflection point at which the refrigerant leak index begins to change continuously from a normal value to an abnormal value.

[0051] Analysis of historical information, such as repair records, from past refrigerant leaks revealed, as shown in Figure 4, that even in the same type of refrigeration and air conditioning equipment 10, there are differences in the refrigerant leakage rate when a leak occurs in the outdoor unit 12, indoor unit 14, and on-site piping 16.

[0052] Therefore, the refrigerant leak location estimation device 30 according to this embodiment uses repair records and operating data from past refrigerant leaks to determine the relationship between the refrigerant leak rate and the refrigerant leak location (for example, correlation data).

[0053] Figures 3A to 3C are graphs illustrating an example of a process for calculating the refrigerant leakage rate from a refrigerant quantity index. The graphs in Figures 3A to 3C show the time change of the refrigerant quantity index (an amount equivalent to the refrigerant quantity) calculated from the operating data of the refrigeration and air conditioning equipment 10. The refrigerant quantity index is a value that is strongly correlated with the refrigerant quantity, and is, for example, the measured degree of subcooling of the refrigeration cycle, or a value corrected for the degree of subcooling and other operating data.

[0054] Figures 3A to 3C show examples of the time evolution of refrigerant quantity indicators at different refrigerant leakage rates. Figure 3A shows an example of the time evolution of the refrigerant quantity indicator when the refrigerant leakage rate is slow (slow leak). Figure 3B shows an example of the time evolution of the refrigerant quantity indicator when the refrigerant leakage rate is fast (rapid leak). Figure 3C shows an example of the time evolution of the refrigerant quantity indicator when the refrigerant leakage rate is intermediate (intermediate leak rate).

[0055] Figures 3A to 3C show that as the refrigerant quantity index decreases from a normal value, and the refrigerant quantity index reaches a threshold, the refrigerant leakage rate can be estimated from the change in the refrigerant quantity index within a unit time ΔT and the conversion factor to the refrigerant quantity.

[0056] As shown in Figures 3A to 3C, a database is created by collecting examples of the relationship between the estimated refrigerant leakage rate and the location of the refrigerant leakage, thereby creating a refrigerant leakage rate distribution, for example, as shown in Figure 4. Figure 4 is a graph of an example of a refrigerant leakage rate distribution. The vertical axis of the graph in Figure 4 shows the frequency of refrigerant leakage in the outdoor unit 12, indoor unit 14, and on-site piping 16. The horizontal axis of the graph in Figure 4 shows the refrigerant leakage rate (kg / year). The graph shown in Figure 4 approximates the refrigerant leakage rate distribution with a log-normal distribution. Note that the refrigerant leakage rate distribution may be approximated with other probability distributions depending on the characteristics of each model of refrigeration and air conditioning equipment 10. As shown in Figure 4, since the peak of the refrigerant leakage rate distribution curve differs depending on the location where the refrigerant leakage occurs, it is possible to estimate the location of the refrigerant leakage (leak location) with a certain degree of confidence from the distance between the refrigerant leakage rate of the newly leaked refrigeration and air conditioning equipment 10 and the peak of each distribution curve.

[0057] Therefore, when the refrigerant leak location estimation device 30 according to this embodiment estimates a newly occurring refrigerant leak location, it estimates the refrigerant leak rate from the operating data. Subsequently, the refrigerant leak location estimation device 30 can estimate one or more refrigerant leak locations that are highly likely to be experiencing a leak by referring to a database created by collecting examples of the relationship between the refrigerant leak rate and the refrigerant leak location.

[0058] As described above, the refrigerant leak location estimation device 30 according to this embodiment estimates the refrigerant leak rate from the operating data of the refrigeration and air conditioning equipment 10 to be repaired, and by using the relationship between the refrigerant leak rate and the refrigerant leak location, it can estimate one or more refrigerant leak locations that are highly likely to be experiencing refrigerant leakage.

[0059] <Processing> The refrigerant leak location estimation device 30 according to this embodiment estimates one or more refrigerant leak locations by, for example, the process shown in Figure 5.

[0060] Figure 5 is a flowchart showing an example of the processing of the refrigerant leak location estimation device 30 according to this embodiment.

[0061] In step S10, the control unit 32 of the refrigerant leak location estimation device 30 acquires operating data of the refrigeration and air conditioning equipment 10 to be repaired, which is used to estimate the location of the refrigerant leak from the refrigerant circuit. The operating data acquired in step S10 only needs to be data that can be used to calculate the refrigerant amount index. The refrigerant amount index is a value that serves as an indicator of the amount of refrigerant filled in the refrigerant circuit of the refrigeration and air conditioning equipment 10, and is the measured degree of subcooling, etc.

[0062] The operating data acquired in step S10 may include the rotational speed of the compressor 20, the rotational speed of the fan, the opening degree of the subcooling expansion valve, the discharge pipe temperature of the compressor 20, the discharge superheat degree, and the outside air temperature in order to correct for fluctuations in the refrigerant amount index due to outside temperature, air conditioning load, etc. The operating data of the refrigeration and air conditioning equipment 10 to be repaired is acquired in real time while the refrigeration and air conditioning equipment 10 is in operation and stored, for example, on a server, and a predetermined period of data necessary for determining refrigerant leakage is acquired from the server in batches.

[0063] In step S12, the control unit 32 calculates a refrigerant quantity index from the operating data acquired in step S10 and determines refrigerant leakage from the change in the refrigerant quantity index. The control unit 32 determines whether or not there is refrigerant leakage by comparing the refrigerant quantity index calculated from the operating data acquired in step S10 with a threshold used to determine whether or not there is refrigerant leakage. Note that the determination of refrigerant leakage in step S12 can be performed using existing technology.

[0064] The control unit 32 repeats the processes in steps S10 to S14 until it determines that there is a refrigerant leak. If it determines in step S14 that there is a refrigerant leak, the control unit 32 proceeds to the process in step S16.

[0065] In step S16, the control unit 32 estimates the refrigerant leakage rate of the refrigeration and air conditioning equipment 10 to be repaired. For example, the control unit 32 estimates the refrigerant leakage rate from the amount of change in the refrigerant amount index of the refrigeration and air conditioning equipment 10 during a period of time ΔT prior to the time when refrigerant leakage was determined, and from a conversion coefficient to the refrigerant amount.

[0066] In step S18, the control unit 32 estimates one or more refrigerant leak locations using historical information that records the relationship between the refrigerant leak rate and the location of the refrigerant leak in past refrigerant leaks, and the refrigerant leak rate estimated in step S16. The historical information that records the relationship between the refrigerant leak rate and the location of the refrigerant leak in past refrigerant leaks increases, for example, when a repair worker inputs the actual refrigerant leak location from the input device 501 to the recording medium 503a after the repair. As the amount of historical information that records the relationship between the refrigerant leak rate and the location of the refrigerant leak in past refrigerant leaks increases, an improvement in the accuracy of estimating the refrigerant leak locations can be expected.

[0067] For example, if the historical information recording the relationship between refrigerant leakage rate and location of past refrigerant leaks is the refrigerant leakage rate distribution shown in Figure 4, the control unit 32 can estimate that the refrigerant leak location is the outdoor unit 12 if the refrigerant leakage rate estimated in step S16 is 40 kg / year or more. If the historical information recording the relationship between refrigerant leakage rate and location of past refrigerant leaks is the refrigerant leakage rate distribution shown in Figure 4, the control unit 32 can estimate that the refrigerant leak location is somewhere other than the outdoor unit 12 if the refrigerant leakage rate estimated in step S16 is less than 40 kg / year. If the control unit 32 estimates that the refrigerant leak location is somewhere other than the outdoor unit 12, it may estimate that the refrigerant leak location is the indoor unit 14 if the refrigerant leakage rate is approximately 10 to 40 kg / year, or estimate that the refrigerant leak location is the on-site piping 16 if the refrigerant leakage rate is less than approximately 10 kg / year.

[0068] In step S20, the control unit 32 notifies the repair worker (service technician, etc.) associated with the refrigeration and air conditioning equipment 10 that was determined to have a refrigerant leak in step S12 of the location of the refrigerant leak estimated in step S18. The notification to the repair worker associated with the refrigeration and air conditioning equipment 10 that was determined to have a refrigerant leak in step S12 can be made using a technology that enables notification to the repair worker (for example, an email function, an application notification function, or a printing function). The notification to the repair worker in step S20 may also be a notification of the refrigerant leak from a monitoring center that monitors the refrigeration and air conditioning equipment 10 to the repair worker.

[0069] According to the flowchart in Figure 5, if a refrigerant leak occurs from the refrigeration and air conditioning equipment 10 to be repaired, the location where the refrigerant leak is most likely to occur (estimated refrigerant leak location) can be notified to repair workers such as service technicians. Service technicians can then investigate starting from the location where the refrigerant leak is most likely to occur, thus reducing the time it takes to identify the refrigerant leak location.

[0070] In the explanation of step S18 above, one or more refrigerant leak locations were estimated using historical information that records the relationship between the refrigerant leak rate and the location of the refrigerant leak in past refrigerant leaks, and the refrigerant leak rate estimated in step S16.

[0071] In step S18, in addition to the refrigerant leakage rate in past refrigerant leaks, historical information recording the relationship between the installation year, location, usage, or model of the refrigeration and air conditioning equipment 10 and the refrigerant leakage location may be used to estimate one or more refrigerant leakage locations from the estimated refrigerant leakage rate at the time of the leak. The installation year, location, usage, or model of the refrigeration and air conditioning equipment 10 are examples of attributes related to the refrigeration and air conditioning equipment 10. The attributes related to the refrigeration and air conditioning equipment 10 may include the name of the contractor. Contractors handling new multi-split air conditioning systems for buildings may not be proficient in complex piping work. In projects handled by contractors who are not proficient in complex piping work, refrigerant leaks due to faulty workmanship are more likely to occur. Thus, because the level of the contractor responsible for the piping work may influence the situation of refrigerant leaks after installation, the name of the contractor may be included in the attributes related to the refrigeration and air conditioning equipment 10.

[0072] The installation year of the refrigeration and air conditioning equipment 10 is the number of years that have passed since the equipment was installed. The incidence rate and location of refrigerant leakage in the refrigeration and air conditioning equipment 10 exhibits characteristics of a bathtub curve, which shows the trend of failure rates in mechanical systems. Specifically, immediately after installation, there are many leaks from on-site piping connections due to installation errors, leaks due to piping corrosion begin to occur a few years after installation, and after 10 years after installation, rapid leaks may occur due to piping rupture caused by metal fatigue. Thus, the installation year of the refrigeration and air conditioning equipment 10 can be used as information to estimate the location of refrigerant leakage in the refrigeration and air conditioning equipment 10. The location of the refrigeration and air conditioning equipment 10 is information about the region in which the equipment is installed, such as coastal areas, hot spring areas, or urban areas. In cases where the equipment is installed near the coast, salt damage is a common cause of leakage, and in cases where it is installed in a hot spring area, corrosive gases often corrode the piping of the outdoor unit 12, leading to leakage. Thus, the location of the refrigeration and air conditioning equipment 10 can be used as information to estimate the location of refrigerant leakage in the refrigeration and air conditioning equipment 10. The intended use of the refrigeration and air conditioning equipment 10 is information about the usage conditions of the room where the refrigeration and air conditioning equipment 10 is installed, such as kitchens, factories, living rooms, or hospitals. For example, corrosive volatile organic compounds may be generated in kitchens, factories, or newly constructed living rooms, which can corrode the indoor unit piping. Thus, the intended use of the room where the refrigeration and air conditioning equipment 10 is installed can be used as information to estimate the location of refrigerant leaks in the refrigeration and air conditioning equipment 10. The model of the refrigeration and air conditioning equipment 10 is a product specification that differs depending on the capacity and intended use of the refrigeration and air conditioning equipment 10, and a model name is assigned to each specific specification. In addition, even if the capacity and intended use are the same, different model names are assigned to equipment released at different times. Since the design specifications and installed parts differ for each model, for example, a certain model may have a high rate of refrigerant leakage from a specific part of the piping or a specific part. Thus, the model of the refrigeration and air conditioning equipment 10 can be used as information to estimate the location of refrigerant leaks in the refrigeration and air conditioning equipment 10.

[0073] The process in step S18 is expected to improve the accuracy of estimating the location of the refrigerant leak by using historical information that records the relationship between the refrigerant leak rate in past refrigerant leaks, as well as the installation year, location, usage, or model of the refrigeration and air conditioning equipment 10 and the location of the refrigerant leak.

[0074] Alternatively, the process in step S18 may involve using a predictive model trained on historical information that records the relationship between refrigerant leakage rate and refrigerant leakage location in past refrigerant leaks to estimate one or more refrigerant leakage locations from the refrigerant leakage rate.

[0075] For example, the control unit 32 uses historical information, which records the relationship between the refrigerant leakage rate and the location of the refrigerant leakage in past refrigerant leaks, as training data to machine-learn a predictive model that outputs the location of the refrigerant leakage in past refrigerant leaks when the refrigerant leakage rate in past refrigerant leaks is input. The machine learning of the predictive model may be performed by a device other than the refrigerant leakage location estimation device 30.

[0076] Furthermore, in step S18, the process may be carried out using a predictive model trained on historical information that records the relationship between the refrigerant leakage rate in past refrigerant leaks, as well as the installation year, location, usage, or model of the refrigeration and air conditioning equipment 10 and the location of the refrigerant leak, in order to estimate one or more refrigerant leak locations from the refrigerant leakage rate. For example, a classification model using a random forest may be used as the predictive model. Alternatively, a generative AI may be used as the predictive model.

[0077] For example, the control unit 32 may use historical information, which records the relationship between the refrigerant leakage location and the installation year, location, usage, or model of the refrigeration and air conditioning equipment 10, in addition to the refrigerant leakage rate in past refrigerant leaks, as training data to machine a predictive model that outputs the location of refrigerant leaks in past refrigerant leaks when the refrigerant leakage rate in past refrigerant leaks and the installation year, location, usage, or model of the refrigeration and air conditioning equipment 10 are input.

[0078] Alternatively, the process in step S18 may be carried out as shown in Figure 6. Figure 6 is a flowchart of an example of the process in step S18. The process in the flowchart of Figure 6 estimates one or more refrigerant leakage locations from the estimated refrigerant leakage rate, using different historical information limited by the installation year, location, usage, or model of the refrigeration and air conditioning equipment 10.

[0079] In step S30, the control unit 32 selects different historical information (a database created by collecting examples of the relationship between refrigerant leakage rate and refrigerant leakage location) that is limited by the installation year, location, usage, or model of the refrigeration and air conditioning equipment 10 to be repaired. For example, in the case of installation year, the control unit 32 determines the relationship between refrigerant leakage rate and refrigerant leakage location from historical information limited to a range such as installation less than one year or installation 10 years or more, and uses this to estimate the refrigerant leakage location of the refrigeration and air conditioning equipment 10 that falls within the limited range. Similarly, in the case of location, for example, it is limited to cities A and B or countries C and D. In the case of usage, for example, it is limited to data centers, kitchens, hospitals, etc. In the case of model, for example, it is limited to model names E, F, etc. The control unit 32 can use different historical information limited by the installation year, location, usage, or model of the refrigeration and air conditioning equipment 10 to be repaired to estimate the refrigerant leakage location. In step S32, the control unit 32 can estimate the location of the refrigerant leak from the refrigerant leak rate using the database selected in step S30 (different historical information limited by the installation year, location, usage, or model of the refrigeration and air conditioning equipment 10 to be repaired). Note that the attributes of the refrigeration and air conditioning equipment 10 that are limited may be one or more.

[0080] The process in step S18 shown in Figure 6 is expected to improve the accuracy of estimating the location of refrigerant leaks by using different historical information limited to the installation year, location, usage, or model of the refrigeration and air conditioning equipment 10 to be repaired.

[0081] Alternatively, the process in step S18 may be carried out as shown in Figure 7. Figure 7 is a flowchart of an example of the process in step S18.

[0082] The flowchart in Figure 7 processes one or more refrigerant leak locations using historical information that records the relationship between the refrigerant leak rate and the location of the refrigerant leak in past refrigerant leaks. Depending on the estimation result (e.g., the accuracy of the estimation), it further estimates one or more refrigerant leak locations using historical information that records the relationship between the refrigerant leak location, as well as the installation year, location, usage, or model of the refrigeration and air conditioning equipment 10, and the refrigerant leak location, in addition to the refrigerant leak rate in past refrigerant leaks.

[0083] In step S40, the control unit 32 uses historical information that records the relationship between the refrigerant leakage rate and the location of the refrigerant leakage in past refrigerant leaks. The control unit 32 estimates the location of the refrigerant leakage from the refrigerant leakage rate estimated in step S16.

[0084] In step S42, the control unit 32 determines whether further estimation of the refrigerant leak location is necessary, based on the results of estimating the refrigerant leak location in step S40. For example, by quantifying the accuracy of the refrigerant leak location estimation in step S40, the control unit 32 may determine whether further estimation of the refrigerant leak location is necessary depending on the level of the estimation accuracy.

[0085] For example, in the graph shown in Figure 4, the accuracy of estimating the location of a refrigerant leak based on the refrigerant leak rate is quantified according to the degree of overlap in the distribution of the frequency distributions of multiple refrigerant leak locations. The greater the overlap, the lower the accuracy of estimating the location of the refrigerant leak based on the refrigerant leak rate, and the less the overlap, the higher the accuracy of estimating the location of the refrigerant leak based on the refrigerant leak rate.

[0086] If the control unit 32 determines that further estimation of the refrigerant leak location is necessary based on the refrigerant leak rate, it proceeds to step S44. If the control unit 32 determines that further estimation of the refrigerant leak location is unnecessary based on the refrigerant leak rate, it skips step S44.

[0087] In step S44, the control unit 32 uses historical information that records the relationship between the refrigerant leakage rate in past refrigerant leaks, as well as the installation year, location, usage, or model of the refrigeration and air conditioning equipment 10 and the location of the refrigerant leak. For example, if the control unit 32 cannot determine the priority order of the likelihood of multiple candidate refrigerant leak locations estimated from the refrigerant leakage rate in step S40, it further uses information regarding the installation year, location, usage, or model of the refrigeration and air conditioning equipment 10 to be repaired to determine the priority order and estimate one or more refrigerant leak locations. Note that the attributes of the refrigeration and air conditioning equipment 10 used for determination in step S44 may be one or more.

[0088] In step S18 shown in Figure 7, if the accuracy of the refrigerant leak location estimation result using historical information that records the relationship between refrigerant leak rate and refrigerant leak location is high, the refrigerant leak location estimated in step S40 is adopted. If the accuracy of the refrigerant leak location estimation result using historical information that records the relationship between refrigerant leak rate and refrigerant leak location is low, the refrigerant leak location estimated in step S44, which is expected to have higher estimation accuracy than step S40, is adopted.

[0089] In step S12 of Figure 5, the determination of refrigerant leakage may be made by estimating the presence or absence of refrigerant leakage using a predictive model trained on historical information that records the relationship between operating data or a refrigerant leakage index in past refrigerant leakage incidents. For example, the control unit 32 trains a predictive model that outputs "refrigerant leakage present" when operating data or a refrigerant leakage index in past refrigerant leakage incidents is input. The machine learning of the predictive model may be performed by a device other than the refrigerant leakage location estimation device 30.

[0090] Furthermore, the above examples show (1) an example of estimating whether the refrigerant leak is in the outdoor unit 12 or another unit, and (2) an example of estimating whether the leak is in the outdoor unit 12, the indoor unit 14, or the on-site piping 16, but the method is not limited to these examples. For example, the refrigerant leak location in the outdoor unit 12 may be divided into the compressor 20, outdoor heat exchanger 21, subcooling heat exchanger 22, four-way switching valve 24, outdoor unit internal piping 25, or valves, etc. Also, the refrigerant leak location in the indoor unit 14 may be divided into the indoor expansion valve, indoor heat exchanger 26, and indoor unit internal piping, etc. In addition, the estimated refrigerant leak location to be notified to the repair worker is not limited to one location, but may be multiple locations.

[0091] As described above, the refrigeration and air conditioning system 1 according to this embodiment provides a refrigerant leak location estimation device 30, a refrigerant leak location estimation method, and a refrigeration and air conditioning system 1 that reduce the time it takes for repair workers to identify the location of a refrigerant leak.

[0092] [Operation] This embodiment is a refrigerant leak location estimation device 30 having a control unit. The control unit 32 determines refrigerant leakage in the refrigeration and air conditioning equipment 10 based on changes in the refrigerant quantity index calculated from the operating data of the refrigeration and air conditioning equipment 10, estimates the refrigerant leakage rate at the time of refrigerant leakage in the refrigeration and air conditioning equipment 10, and estimates one or more refrigerant leak locations from the estimated refrigerant leakage rate at the time of refrigerant leakage using information recorded on the relationship between the refrigerant leakage rate and the refrigerant leakage location in past refrigerant leaks.

[0093] In this embodiment, the refrigerant leakage rate when refrigerant leaks from the refrigeration and air conditioning equipment 10 is estimated. It has been found that the refrigerant leakage rate when refrigerant leaks from the refrigeration and air conditioning equipment 10 shows different tendencies (differences in average leakage amount) depending on the location of the refrigerant leak. Therefore, in this embodiment, one or more refrigerant leak locations are estimated from the estimated refrigerant leakage rate at the time of the refrigerant leak, using information recorded on the relationship between the refrigerant leakage rate and the location of the refrigerant leak in past refrigerant leaks.

[0094] By using information recorded on the relationship between refrigerant leakage rate and the location of refrigerant leakage in past refrigerant leaks, this embodiment allows for the estimation of locations where refrigerant leakage is likely to occur with higher accuracy. Thus, in this embodiment, the investigation can begin from one or more refrigerant leakage locations estimated by the refrigerant leakage location estimation device 30, thereby reducing the time it takes for repair workers to identify the refrigerant leakage location.

[0095] Furthermore, the control unit 32 uses historical information, which includes the refrigerant leakage rate in past refrigerant leaks, as well as attributes related to the refrigeration and air conditioning equipment 10 and the relationship between the refrigerant leakage location, to estimate one or more refrigerant leakage locations based on the estimated refrigerant leakage rate at the time of the leak.

[0096] In this embodiment, by using historical information that records the relationship between the refrigerant leakage rate in past refrigerant leaks, as well as attributes related to the refrigeration and air conditioning equipment 10 and the location of the refrigerant leak, it is possible to estimate one or more refrigerant leak locations and thereby improve the accuracy of estimating the location of the refrigerant leak.

[0097] Furthermore, the control unit 32 uses a predictive model trained on historical data to estimate one or more refrigerant leak locations based on the estimated refrigerant leak rate at the time of the leak.

[0098] In this embodiment, a predictive model trained on historical information, which records the relationship between refrigerant leakage rate and refrigerant leakage location in past refrigerant leaks, can be used to estimate locations where refrigerant leaks are likely to occur with higher accuracy.

[0099] Furthermore, the control unit 32 uses historical information, limited to a specific range from among the attributes of one or more refrigeration and air conditioning units 10, to estimate one or more refrigerant leakage locations from the estimated refrigerant leakage rate at the time of refrigerant leakage.

[0100] In this embodiment, by using historical information limited to a specific range among the attributes of one or more refrigeration and air conditioning units 10, if there is a different trend in the relationship between the refrigerant leakage rate and the refrigerant leakage location in the historical information limited to a specific range among the attributes of one or more refrigeration and air conditioning units 10, it is possible to expect an improvement in the accuracy of estimating the refrigerant leakage location.

[0101] Furthermore, the control unit 32 uses historical information that records the relationship between the refrigerant leakage rate and the location of the refrigerant leakage in past refrigerant leaks to estimate one or more candidate refrigerant leakage locations based on the estimated refrigerant leakage rate at the time of the refrigerant leakage. Then, using historical information that records the relationship between the attributes of one or more refrigeration and air conditioning equipment and the location of the refrigerant leakage, the control unit 32 selects one or more candidate refrigerant leakage locations from the estimated candidate locations.

[0102] According to this embodiment, first, using historical information that records the relationship between the refrigerant leakage rate and the location of the refrigerant leakage in past refrigerant leaks, one or more candidate refrigerant leakage locations can be estimated from the estimated refrigerant leakage rate at the time of the refrigerant leak. If the accuracy of the estimation result is high, the control unit 32 can adopt the result of the initial estimation of the refrigerant leakage location. If the accuracy of the estimation result is low, the control unit 32 can select and adopt one or more candidate refrigerant leakage locations from the estimated candidate refrigerant leakage locations using historical information that records the relationship between the attributes of one or more refrigeration and air conditioning equipment and the refrigerant leakage location.

[0103] Furthermore, attributes related to the refrigeration and air conditioning equipment 10 include the number of years since installation, location, intended use, or model of the refrigeration and air conditioning equipment 10.

[0104] According to this embodiment, the number of years installed, location, intended use, or model of the refrigeration and air conditioning equipment 10 can be used as attributes related to the refrigeration and air conditioning equipment 10.

[0105] Furthermore, the control unit 32 notifies the repair worker associated with the refrigeration and air conditioning equipment 10 that detected the refrigerant leak of one or more estimated refrigerant leak locations.

[0106] According to this embodiment, the time required to identify the refrigerant leak location can be reduced by notifying the repair worker associated with the refrigeration and air conditioning equipment 10 that has detected the refrigerant leak of one or more estimated refrigerant leak locations.

[0107] Furthermore, the control unit 32 estimates the indoor unit 14, outdoor unit 12, or on-site piping 16 of the refrigeration and air conditioning equipment 10 as the location of the refrigerant leak.

[0108] According to this embodiment, the indoor unit 14, outdoor unit 12, or on-site piping 16 of the refrigeration and air conditioning equipment 10 can be estimated as the location of the refrigerant leak.

[0109] Furthermore, this embodiment is a refrigerant leak location estimation method performed by a refrigerant leak location estimation device 30 having a control unit 32, wherein the control unit 32 determines refrigerant leakage in the refrigeration and air conditioning equipment 10 based on changes in the refrigerant amount index calculated from the operating data of the refrigeration and air conditioning equipment 10, estimates the refrigerant leakage rate at the time of refrigerant leakage in the refrigeration and air conditioning equipment 10, and estimates one or more refrigerant leak locations from the estimated refrigerant leakage rate at the time of refrigerant leakage using information recorded on the relationship between the refrigerant leakage rate and the refrigerant leak location in past refrigerant leaks.

[0110] This embodiment provides a method for estimating the location of a refrigerant leak that reduces the time it takes for repair workers to identify the leak location.

[0111] Furthermore, this embodiment is a refrigeration and air conditioning system 1 comprising a refrigeration and air conditioning device 10 and an information processing device having a control unit 32, wherein the control unit 32 determines refrigerant leakage from the refrigeration and air conditioning device 10 based on changes in the refrigerant quantity index calculated from the operating data of the refrigeration and air conditioning device 10, estimates the refrigerant leakage rate at the time of refrigerant leakage from the refrigeration and air conditioning device 10, and estimates one or more refrigerant leakage locations from the estimated refrigerant leakage rate at the time of refrigerant leakage using information recorded in which the relationship between the refrigerant leakage rate and the refrigerant leakage location in past refrigerant leaks is recorded.

[0112] According to this embodiment, a refrigeration and air conditioning system 1 can be provided that reduces the time it takes for repair workers to identify the location of a refrigerant leak.

[0113] Although this embodiment has been described above, it will be understood that various modifications to the form and details are possible without departing from the spirit and scope of the claims. Although the present invention has been described above based on examples, the present invention is not limited to the above examples, and various modifications are possible within the scope described in the claims. This application claims priority to Basic Application No. 2024-171336 filed with the Japan Patent Office on September 30, 2024, the entire contents of which are incorporated herein by reference.

[0114] 1 Refrigeration and Air Conditioning System 10 Refrigeration and Air Conditioning Equipment 12 Outdoor Unit 14 Indoor Unit 16 On-site Piping 30 Refrigerant Leakage Location Estimation Device 32 Control Unit

Claims

1. A refrigerant leak location estimation device having a control unit, wherein the control unit determines refrigerant leakage of the refrigeration and air conditioning equipment based on changes in the refrigerant quantity index calculated from the operating data of the refrigeration and air conditioning equipment, estimates the refrigerant leakage rate at the time of refrigeration leakage of the refrigeration and air conditioning equipment, and estimates one or more refrigerant leak locations from the estimated refrigerant leakage rate at the time of refrigerant leakage using information recorded on the relationship between the refrigerant leakage rate and the refrigerant leak location in past refrigerant leaks.

2. The refrigerant leak location estimation device according to claim 1, wherein the control unit estimates one or more refrigerant leak locations from the estimated refrigerant leak rate at the time of the refrigerant leak, using historical information which records the relationship between the refrigerant leak rate at one or more refrigeration and air conditioning equipment and the refrigerant leak location, in addition to the refrigerant leak rate at the time of the refrigerant leak that occurred in the past.

3. The refrigerant leak location estimation device according to claim 2, wherein the control unit estimates one or more refrigerant leak locations from the estimated refrigerant leak rate at the time of refrigerant leak using a predictive model trained on the historical information.

4. The refrigerant leak location estimation device according to claim 2, wherein the control unit estimates one or more refrigerant leak locations from the estimated refrigerant leak rate at the time of refrigerant leak using the historical information, which is further limited to a specific range among the attributes relating to one or more refrigeration and air conditioning equipment.

5. The control unit uses historical information that records the relationship between the refrigerant leakage rate and the location of the refrigerant leakage in past refrigerant leaks to estimate one or more candidate refrigerant leakage locations from the estimated refrigerant leakage rate at the time of the refrigerant leakage, and further uses historical information that records the relationship between the attribute of one or more refrigeration and air conditioning equipment and the location of the refrigerant leakage to select one or more candidate refrigerant leakage locations from the estimated candidate refrigerant leakage locations, as described in claim 2.

6. The refrigerant leak location estimation device according to claim 2, wherein the attribute relating to the refrigeration and air conditioning equipment is the number of years installed, location, intended use, or model of the refrigeration and air conditioning equipment.

7. The refrigerant leak location estimation device according to any one of claims 1 to 6, wherein the control unit notifies a repair worker associated with the refrigeration and air conditioning equipment that determined the refrigerant leak of the estimated one or more refrigerant leak locations.

8. The refrigerant leak location estimation device according to any one of claims 1 to 7, wherein the control unit estimates the indoor unit, outdoor unit, or on-site piping of the refrigeration and air conditioning equipment as the refrigerant leak location.

9. A method for estimating a refrigerant leak location, which is performed by a refrigerant leak location estimation device having a control unit, wherein the control unit determines refrigerant leakage of the refrigeration and air conditioning equipment based on changes in a refrigerant quantity index calculated from the operating data of the refrigeration and air conditioning equipment, estimates the refrigerant leakage rate at the time of refrigeration leakage of the refrigeration and air conditioning equipment, and estimates one or more refrigerant leak locations from the estimated refrigerant leakage rate at the time of refrigerant leakage using information recorded in relation to the relationship between the refrigerant leakage rate and the refrigerant leak location in past refrigerant leaks.

10. A refrigeration and air conditioning system comprising a refrigeration and air conditioning device and an information processing device having a control unit, wherein the control unit determines refrigerant leakage of the refrigeration and air conditioning device based on changes in a refrigerant quantity index calculated from the operating data of the refrigeration and air conditioning device, estimates the refrigerant leakage rate at the time of refrigerant leakage of the refrigeration and air conditioning device, and estimates one or more refrigerant leakage locations from the estimated refrigerant leakage rate at the time of refrigerant leakage using information recorded in relation to the refrigerant leakage rate and refrigerant leakage location in past refrigerant leaks.

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