Air conditioner, detection device, refrigerant leak detection method, program, and storage medium

Abstract

The present invention provides an air conditioner, a detection device, a refrigerant leak detection method, a program, and a storage medium that can detect the rapid leakage of a flammable refrigerant. [Solution] The air conditioner uses a flammable refrigerant. The air conditioner includes refrigerant piping through which the refrigerant flows, a pressure sensor, and a control unit. The pressure sensor is installed in the refrigerant piping and acquires pressure information related to the pressure of the refrigerant in the refrigerant piping. The control unit acquires the pressure information from the pressure sensor and, based on the pressure information, determines whether the pressure change within a predetermined time is greater than a change threshold, and based on the determination result, detects rapid leakage of the refrigerant.

Description

Technical Field

[0001] The present disclosure relates to an air conditioner, a detection device, a refrigerant leakage detection method, a program, and a storage medium.

Background Art

[0002] Conventionally, as described in Patent Document 1, there is known a technique for detecting whether a flammable refrigerant has leaked from an air conditioner using a refrigerant detection sensor disposed inside the casing of the air conditioner. This refrigerant detection sensor is a gas sensor and detects the presence of a specific type of refrigerant.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, conventional air conditioners can only detect the presence or absence of refrigerant leakage. Therefore, conventionally, there is a problem that there is no means for detecting the leakage rate and rapid leakage cannot be detected.

[0005] An object of the present disclosure is to provide an air conditioner, a detection device, a refrigerant leakage detection method, a program, and a storage medium that can detect rapid leakage of a flammable refrigerant.

Means for Solving the Problems

[0008] One embodiment of the detection device according to this disclosure detects refrigerant leakage in an air conditioner. The detection device includes a communication unit and a control unit. The communication unit acquires pressure information related to the pressure of the refrigerant flowing through the refrigerant piping of the air conditioner. Based on the pressure information, the control unit determines whether the pressure change within a predetermined time is greater than a change threshold, and based on the determination result, detects rapid refrigerant leakage.

[0009] One embodiment of the refrigerant leak detection method according to the present disclosure detects refrigerant leaks in an air conditioner and is executable by the air conditioner. The refrigerant leak detection method includes the steps of: acquiring pressure information related to the pressure of the refrigerant flowing through the refrigerant piping using a pressure sensor provided in the refrigerant piping of the air conditioner; determining, based on the pressure information, whether the pressure change within a predetermined time is greater than a change threshold; and detecting a rapid refrigerant leak based on the determination result.

[0010] One embodiment of the refrigerant leak detection method relating to this disclosure detects refrigerant leaks in an air conditioner and can be performed by a detection device. The refrigerant leak detection method includes the steps of: acquiring pressure information related to the pressure of the refrigerant flowing through the refrigerant piping of the air conditioner; determining, based on the pressure information, whether or not the pressure change within a predetermined time is greater than a change threshold; and detecting a rapid refrigerant leak based on the determination result.

[0011] Other embodiments of the program relating to this disclosure cause an air conditioner to execute a refrigerant leak detection method, or cause a detection device to execute a refrigerant leak detection method.

[0012] Furthermore, other embodiments of the storage medium relating to this disclosure are non-temporary, computer-readable storage media on which a computer program is stored. The refrigerant leak detection method is performed when the computer program is executed by the processor. [Effects of the Invention]

[0013] In this disclosure, an air conditioner, a detection device, a refrigerant leak detection method, a program, and a storage medium can be used to detect the rapid leakage of a flammable refrigerant. [Brief explanation of the drawing]

[0014] [Figure 1] Block diagram showing an example of the schematic configuration of the air conditioner in Embodiment 1. [Figure 2] Schematic diagram of the refrigeration cycle in Embodiment 1 [Figure 3] Flowchart of an example of a refrigerant leak detection method in Embodiment 1 [Figure 4A] Schematic diagram of refrigerant pressure changes under normal conditions [Figure 4B] Schematic diagram of refrigerant pressure change during rapid leakage. [Figure 5] Another example flowchart of the refrigerant leak detection method in Embodiment 1 [Figure 6] Schematic diagram of the refrigeration cycle in Embodiment 1 [Figure 7] Flowchart of an example of a refrigerant leak detection method in Embodiment 2 [Figure 8] Schematic diagram of refrigerant pressure change during minute leakage [Figure 9] Flowchart of an example of a refrigerant leak detection method in Embodiment 3 [Figure 10A] Block diagram showing an example of the schematic configuration of the detection device in Embodiment 4. [Figure 10B] Block diagram showing another example of the schematic configuration of the detection device in Embodiment 4. [Figure 11] Flowchart of an example of a refrigerant leak detection method in Embodiment 4

Mode for Carrying Out the Invention

[0015] 《Technical Concept》 Before explaining specific embodiments of the air conditioner, air conditioner, detection device, refrigerant leakage detection method, program, and storage medium according to the present disclosure, first, using an example, the technical concept described in the present disclosure will be explained. In this example, the air conditioner uses a flammable refrigerant (that is, a flammable refrigerant) to perform the function of air conditioning.

[0016] In recent years, from the perspective of preventing global warming, it has been required to use refrigerants with a low global warming potential (GWP). As refrigerants with a small GWP, for example, propane (R290) and the like have been considered. Since refrigerants such as propane are flammable, if the refrigerant leaks from the refrigerant piping, there is a risk of ignition. When the leakage rate of the refrigerant is relatively large, a large flammable region is likely to be formed in a short time compared to the case where the leakage rate is relatively small. Therefore, when rapid leakage of a flammable refrigerant occurs, the probability of ignition increases.

[0017] The main concept of the refrigerant leakage detection method of the present disclosure is to detect rapid leakage of a flammable refrigerant in an air conditioner. The rapid leakage of the refrigerant in the present disclosure means leakage that progresses at a leakage rate greater than a predetermined value. The refrigerant leakage detection method of the present disclosure determines whether the refrigerant is rapidly leaking based on the pressure change of the refrigerant flowing in the refrigerant piping of the air conditioner. For example, if it is determined by a pressure sensor that the pressure of the refrigerant gas in the refrigerant piping is rapidly decreasing, rapid leakage can be detected. With the technology of the present disclosure, rapid leakage can be detected, so that appropriate countermeasures can also be taken in response to the detection of rapid leakage of the refrigerant.

[0018] Such a refrigerant leakage detection method can be executed by an air conditioner. Also, the refrigerant leakage detection method can be executed by a detection device other than an air conditioner, for example, a server or a terminal device communicatively connected to the air conditioner.

[0019] Each of the embodiments described below is an example of the present disclosure. The numerical values, shapes, configurations, steps, and order of steps shown in each of the following embodiments are illustrative and not limiting to the present disclosure. Among the components in Embodiment 1 below, those components that are not described in the independent claim representing the highest-level concept are described as optional components.

[0020] In each of the embodiments described below, variations may be shown for certain elements, and other elements may be combined with any configuration as appropriate, with each combined configuration producing its respective effect. In each embodiment, the effects of each variation are achieved by combining the configurations of each variation.

[0021] In the following detailed descriptions, terms such as “First,” “Second,” etc., are used for illustrative purposes only and should not be understood as expressing or implying relative importance or ranking of technical features. Features designated as “First” or “Second” express or imply that they include one or more such features.

[0022] Embodiment 1 Hereinafter, Embodiment 1 of the air conditioner, detection device, refrigerant leak detection method, program, and storage medium relating to this disclosure will be described in detail with reference to the drawings as appropriate. The air conditioner controls a specific internal space as the target of air conditioning control (hereinafter referred to as the control space) and harmonizes the air within the control space.

[0023] Figure 1 is a block diagram showing an example of the schematic configuration of the air conditioner 10 in Embodiment 1. The air conditioner 10 can perform a refrigerant leak detection method and detect rapid refrigerant leakage.

[0024] In the embodiment shown in Figure 1, the air conditioner 10 includes a storage unit 11, a communication unit 12, a control unit 13, a display unit 14, a pressure sensor 15, and a refrigeration cycle 20. The refrigeration cycle 20 includes refrigerant piping 21, a compressor 22, an expansion valve 23, a four-way valve 24, an indoor heat exchanger 25, and an outdoor heat exchanger 26. Note that an air conditioner 10 that can only operate either a cooling cycle or a heating cycle may not include the four-way valve 24.

[0025] A flammable refrigerant flows through the refrigerant piping 21, and the direction of refrigerant flow differs depending on the operating mode of the air conditioner 10 (cooling mode or heating mode). Examples of flammable refrigerants include R-290, R-32, R-1234yf, R-1234ze, R-600a, R-1270, and R-717.

[0026] The air conditioner 10 can connect to a terminal device 60 and / or a server 50 via a communication unit 12. For example, the air conditioner 10 may connect to a terminal device 60, which is the remote controller of the air conditioner 10, via infrared. The air conditioner 10 may connect to a terminal device 60, which is the user's smartphone, via the Internet. The air conditioner 10 may also connect to a server 50 via the Internet.

[0027] The following is an overview of each component.

[0028] <Air conditioner 10> The air conditioner 10 is designed to control an interior space of a room in a home or office, for example, as the target of air conditioning control. The air conditioner 10 shown in Figure 1 includes an indoor unit 30 installed on the wall or ceiling of the control space and an outdoor unit 40 installed outdoors, in a central air conditioning room other than the control space. The air conditioner 10 has, for example, a cooling function, a heating function, a dehumidifying function, and / or an air purifying function. Note that a stationary type air conditioner 10 does not necessarily include an outdoor unit 40. Components other than the piping between the indoor unit 30 and the outdoor unit 40, such as the control unit 13 and the compressor 22, can be arranged inside the housing of the indoor unit 30 or the outdoor unit 40.

[0029] <Storage section 11> The storage unit 11 is a recording medium for recording various information and control programs, and may also be a memory that functions as a work area for the control unit 13. The storage unit 11 can be implemented as, for example, flash memory, RAM (Random Access Memory), ROM (Read Only Memory), other storage devices, or a combination thereof as appropriate.

[0030] The storage unit 11 may store criteria and thresholds for refrigerant leak detection, for example, a threshold for detecting whether refrigerant is leaking rapidly. Information acquired by various sensors, such as the pressure sensor 15, can be stored in the storage unit 11. Information acquired from the terminal device 60 or server 50 can also be stored in the storage unit 11. This information can be read by the control unit 13 when the refrigerant leak detection method is performed.

[0031] The storage unit 11 may store a computer program (sometimes abbreviated as "program" in this disclosure) that causes the air conditioner 10 to execute a refrigerant leak detection method. The storage unit 11 may also include a non-temporary computer-readable storage medium on which the computer program is stored.

[0032] <Communications Section 12> The communication unit 12 can also communicate with the server 50, the user's terminal device 60, etc., and can, for example, send and receive IP packets. As described above, the control unit 13 may cooperate with the server 50 and / or terminal device 60 via the communication unit 12. The communication unit 12 may communicate between the air conditioner 10 and the terminal device 60, the server 50, or the external information source 90 in accordance with standards such as Wi-Fi®, IEEE802.2, IEEE802.3, 3G, LTE, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication network, infrared, Bluetooth®, etc., and send and receive data.

[0033] <Control Unit 13> The control unit 13 is a controller that is responsible for controlling at least some of the functions of the air conditioner 10. The control unit 13 includes a general-purpose processor such as a CPU, MPU, MCU, FPGA, DSP, or ASIC that realizes predetermined functions by executing a program. The control unit 13 can realize various controls in the air conditioner 10 by calling and executing a control program stored in the memory unit 11. In addition, the control unit 13 can work in cooperation with the memory unit 11 to read and write data stored in the memory unit 11. The control unit 13 is not limited to realizing predetermined functions through the cooperation of hardware and software, but may also be a hardware circuit specifically designed to realize predetermined functions.

[0034] The control unit 13 can receive various commands and settings from the terminal device 60 via the communication unit 12. Based on these settings and detected values ​​received from various sensors (e.g., indoor humidity, outdoor humidity), the control unit 13 controls each component of the air conditioner 10 to perform its air conditioning function. The control unit 13 also detects rapid refrigerant leakage in the air conditioner 10 based on a refrigerant leakage detection method described later.

[0035] <Presentation part 14> The display unit 14 is for presenting information using at least one of the following: numbers, characters, images, and sound. The display unit 14 may include a display for presenting a graphical user interface (GUI) and a speaker or buzzer for presenting sound. The air conditioner 10 can output an alarm or notification via the display unit 14 in response to, for example, the detection of a refrigerant leak. However, if the alarm or notification is output via the terminal device 60, or if the alarm or notification is output to the server 50, the air conditioner 10 does not need to include the display unit 14.

[0036] <Pressure sensor 15> The air conditioner 10 includes at least one pressure sensor 15. The pressure sensor 15 is a sensor for acquiring pressure information related to the pressure of the refrigerant in the refrigerant piping 21. For example, the pressure sensor 15 can detect the absolute pressure or gauge pressure, or a change in pressure, in the refrigerant piping 21 and output the detected information as pressure information.

[0037] The pressure sensor 15 may be located inside or outside the refrigerant piping 21, or partially inside the refrigerant piping 21. The pressure sensor 15 may be located on the indoor unit 30 or on the outdoor unit 40. The detection results of the pressure sensor 15 will differ depending on its location in the refrigerant piping 21. Basically, the pressure sensor 15 is positioned to acquire pressure information related to the pressure of the gaseous refrigerant (i.e., refrigerant gas) in the refrigerant piping 21. In addition, multiple pressure sensors 15 may be provided at multiple locations in the refrigerant piping 21 to detect leaks more quickly or accurately.

[0038] Figure 2 is a schematic diagram of the refrigeration cycle 20 in Embodiment 1. Figure 2 shows the components related to the refrigeration cycle 20 in the air conditioner 10, and the black circles indicate examples of the placement positions of the pressure sensor 15 (placement positions p1 to p4).

[0039] In one embodiment, the pressure sensor 15 is located inside the outdoor unit 40, and can be located, for example, at the location p1 shown in Figure 2. When the pressure sensor 15 is located inside the outdoor unit 40, it is easy to install the pressure sensor 15 during production of the air conditioner 10.

[0040] In one embodiment, the pressure sensor 15 is located in the refrigerant piping 21 within the indoor unit 30. For example, the pressure sensor 15 can be placed at position p2 or position p3 shown in Figure 2. Generally, even if a leak occurs outdoors, the leaked refrigerant is diluted by the atmosphere, so the risk is relatively low. Therefore, it is often desirable to detect indoor leaks, which pose a relatively higher risk. When the pressure sensor 15 is placed in the indoor unit 30, the location from which pressure information is acquired is close to the location of the leak to be detected (i.e., indoors), resulting in relatively high sensitivity for leak detection.

[0041] In one embodiment, the pressure sensor 15 is located in the refrigerant piping 21, specifically in the portion located inside the indoor unit 30, and between the indoor heat exchanger 25 and the compressor 22. For example, the pressure sensor 15 can be positioned at location p3 shown in Figure 2. The pressure sensor 15 at location p3 can acquire gaseous refrigerant pressure information whether the refrigeration cycle 20 is performing a cooling cycle or a heating cycle. As an alternative example, the pressure sensor 15 is located in the refrigerant piping 21, specifically in the portion located inside the outdoor unit 40, and between the indoor heat exchanger 25 and the compressor 22. Although this position is in the outdoor unit 40, it can still acquire gaseous refrigerant pressure information.

[0042] In one embodiment, the pressure sensor 15 is located in the refrigerant piping 21 near the compressor 22. For example, the pressure sensor 15 can be located at position p4 shown in Figure 2. Even when a cooling cycle or heating cycle is performed, there are differences in pressure and temperature between the upstream and downstream sides of the compressor 22, but basically, the refrigerant is in a gaseous state near the compressor 22. Therefore, the pressure sensor 15 located near the compressor 22 can acquire pressure information of the gaseous refrigerant.

[0043] The air conditioner 10 may further include sensors to acquire various information from outside the air conditioner 10 in order to perform its function. For example, the air conditioner 10 may include an indoor temperature sensor that detects the temperature of the indoor air drawn into the indoor unit 30 from the control space, and an outdoor temperature sensor that detects the temperature of the outside air in the control space.

[0044] These sensors, including the pressure sensor 15, can acquire information for refrigerant leak detection and for performing air conditioning functions. The information detected by the sensors is input to and stored in the storage unit 11, and later used by the control unit 13 or transmitted to the terminal device 60 or server 50.

[0045] <Indoor unit 30 and outdoor unit 40> In the embodiment shown in Figure 1, the air conditioner 10 includes an indoor unit 30 and an outdoor unit 40. The indoor unit 30 includes an indoor fan 31, and the outdoor unit 40 includes an outdoor fan 41. For example, the storage unit 11, communication unit 12, control unit 13, and indoor heat exchanger 25 can be arranged within the housing of the indoor unit 30, while the compressor 22, expansion valve 23, four-way valve 24, and outdoor heat exchanger 26 can be arranged within the housing of the outdoor unit 40.

[0046] <Server 50> The server 50 may be, for example, a management server of the manufacturer of the air conditioner 10 for managing at least one air conditioner 10 or for collecting data. Alternatively, the server 50 may be an application server. The server 50 can obtain detection results regarding refrigerant leaks from the air conditioner 10 and information detected by at least one sensor of the air conditioner 10 via the Internet, and transfer this information to the terminal device 60. The server 50 can also cooperate with the air conditioner 10 and / or the terminal device 60 to take corrective action in response to leak detection.

[0047] <Terminal device 60> The terminal device 60 is a device related to the air conditioner 10. The terminal device 60 may be, for example, a controller for the air conditioner 10, or a controller capable of managing and controlling multiple types of home appliances. Alternatively, the terminal device 60 may be an information terminal capable of data communication with the air conditioner 10, such as a smartphone, mobile phone, tablet, wearable device, or computer with a dedicated related application 61 installed.

[0048] The control unit 13 or server 50 of the air conditioner 10 can obtain settings or commands entered by the user via the terminal device 60. The terminal device 60 can obtain detection results regarding refrigerant leaks and information detected by at least one sensor of the air conditioner 10 from the air conditioner 10 or server 50 via the internet. In addition, the terminal device 60 can cooperate with the air conditioner 10 and / or server 50 to take countermeasures in response to leak detection. For example, if the terminal device 60 includes a display unit including a display and speaker, the terminal device 60 can notify the user of a rapid refrigerant leak via the display unit in response to the detection of a rapid refrigerant leak.

[0049] <Refrigerant Leak Detection Method> The air conditioner 10 performs a refrigerant leak detection method. More specifically, the control unit 13 of the air conditioner 10 works in cooperation with the memory unit 11 and the pressure sensor 15 to perform the refrigerant leak detection method. This refrigerant leak detection method can detect rapid refrigerant leaks. Furthermore, appropriate countermeasures can be taken in response to the detection of rapid refrigerant leaks.

[0050] Figure 3 is a flowchart of the refrigerant leak detection method in Embodiment 1, and the refrigerant leak detection method shown in Figure 3 includes steps S110 to S130. In one embodiment, the control unit 13 of the air conditioner 10 may periodically execute the refrigerant leak detection method. The control unit 13 may execute the refrigerant leak detection method regardless of whether the air conditioner 10 is operating or not.

[0051] In the refrigerant leak detection method, the control unit 13 of the air conditioner 10 acquires pressure information related to the pressure of the refrigerant in the refrigerant piping 21 using a pressure sensor 15 (step S110). The period during which the control unit 13 acquires pressure information using the pressure sensor 15 may be, for example, 3 minutes, 60 seconds, 30 seconds, 15 seconds, 10 seconds, 5 seconds, 3 seconds, 1 second, or less than 1 second.

[0052] Next, the control unit 13 determines, based on the pressure information acquired in step S110, whether the pressure change within a predetermined time is greater than a change threshold (step S120). Based on the determination result, the control unit 13 detects a rapid refrigerant leak (step S130). The predetermined time in step S120 should be greater than or equal to the pressure information acquisition cycle. For example, the predetermined time may be 5 minutes, 3 minutes, 60 seconds, 30 seconds or less, 15 seconds, 10 seconds, 5 seconds, 3 seconds, 1 second, or 1 second or less. This predetermined time may also be the execution cycle of the refrigerant leak detection method. Furthermore, for prompt action, the predetermined time may be 30 seconds or less.

[0053] More specifically, the control unit 13 determines, based on pressure information, how much the refrigerant pressure in the refrigerant piping 21 has risen or fallen over a predetermined period of time. If the pressure has fallen, the control unit 13 determines whether the amount of fall is greater than the change threshold. That is, the change threshold is the threshold for the amount of refrigerant pressure fall per unit time. If the refrigerant pressure falls by more than the change threshold within the predetermined period of time, the control unit 13 determines that the refrigerant is leaking rapidly and detects the rapid refrigerant leak. On the other hand, if the control unit 13 determines that the refrigerant pressure has risen or fallen by an amount less than or equal to the change threshold within the predetermined period of time, the control unit 13 determines that the refrigerant is not leaking rapidly.

[0054] In one embodiment, the change threshold was set considering the possibility of ignition due to refrigerant leakage. As mentioned above, when the refrigerant leakage rate is relatively high, a relatively large flammable area is more likely to form in a shorter time compared to when the leakage rate is relatively low.

[0055] The change threshold can be set based on experimental results (simulation results) regarding refrigerant leakage and ignition. For example, the change threshold can be set based on experimental results regarding the refrigerant leakage rate and the likelihood of ignition. As an example, when the refrigerant is R290, the change threshold is set according to leakage rates of 10 kg / h or more, 7.5 kg / h or more, or 5 kg / h.

[0056] In addition to the leakage rate, several other factors can influence the likelihood of ignition. For example, different types of refrigerants have different autoignition temperatures and lower flammability limits (LFLs), resulting in different likelihoods of ignition in general use. The LFL is the minimum concentration of refrigerant at which a flame can propagate when the refrigerant and air are uniformly mixed. When the LFL is relatively low, a flammable region is easily created even with a relatively low leakage rate, thus increasing the likelihood of ignition. Therefore, the change threshold can be further set based on the type of refrigerant.

[0057] Furthermore, the internal volume of the refrigerant piping 21 and the amount of refrigerant charged in the air conditioner 10 can affect the leakage rate and may be taken into consideration when setting the change threshold. In one embodiment, the change threshold may be set based on at least one of the following: the type of refrigerant, the internal volume of the refrigerant piping 21, and the amount of refrigerant charged in the air conditioner 10. As an example, the change threshold may be set to the amount of pressure drop per unit time corresponding to a specific leakage rate (e.g., 7.5 kg / h).

[0058] In one embodiment, the control unit 13 can identify the type of refrigerant used in the air conditioner 10, the internal volume of the refrigerant piping 21, and the amount of refrigerant charged, based on the model or identification information (hereinafter abbreviated as "identification information, etc.") of the air conditioner 10. In this case, the control unit 13 can identify the identification information, etc. of the air conditioner 10 and obtain a change threshold associated with the identification information, etc. of the air conditioner 10. In one example, the change threshold associated with the air conditioner 10 is stored in the storage unit 11, and the control unit 13 obtains the change threshold by reading it from the storage unit 11. In another example, the control unit 13 obtains the change threshold from the server 50 by querying the server 50 via the communication unit 12 using the identification information, etc. of the air conditioner 10. Then, the control unit 13 executes a refrigerant leak detection method using the change threshold corresponding to the identification information, etc.

[0059] The following explains the refrigerant pressure change when a rapid leak occurs, using Figures 4A and 4B. Figure 4A is a schematic diagram of the refrigerant pressure change under normal conditions, and Figure 4B is a schematic diagram of the refrigerant pressure change when a rapid leak occurs.

[0060] Since the saturation temperature of a refrigerant changes with ambient temperature, the pressure of the refrigerant gas changes slightly with changes in indoor and outdoor temperatures. Therefore, as shown in Figure 4A, during normal operation when the system is stopped, the pressure of the refrigerant gas gradually rises and falls within a certain range. For example, if the refrigerant is R-290, the pressure will gradually change within a range of approximately 1.2 MPa to 0.5 MPa during normal operation.

[0061] On the other hand, experiments have shown that when a rapid leak of refrigerant occurs, the pressure of the refrigerant gas drops rapidly. During period D1 shown in Figure 4B, the pressure of the refrigerant gas drops rapidly in a short time in response to the rapid leak of refrigerant. Then, during period D2, the liquid phase refrigerant evaporates and the refrigerant gas is replenished, and the pressure equalizes. Then, during period D3, the temperature of the refrigerant decreases due to the latent heat of vaporization, and the pressure of the refrigerant gas gradually decreases further.

[0062] Therefore, the refrigerant leak detection method and air conditioner 10 described above can detect a rapid refrigerant leak by detecting a rapid drop in the refrigerant pressure in the refrigerant piping 21.

[0063] Figure 5 is a flowchart of another example of the refrigerant leak detection method in Embodiment 1. The refrigerant leak detection method shown in Figure 5 includes steps S110 to S140, and steps S110 to S130 in Figure 5 are the same as steps S110 to S130 in Figure 3, so the details are omitted here.

[0064] In the refrigerant leak detection method shown in Figure 5, the control unit 13 detects a rapid refrigerant leak and then performs a first corrective action in response to the detection of further rapid leaks (step S140). The air conditioner 10 may perform the first corrective action independently, or it may perform the first corrective action in cooperation with the server 50 and / or terminal device 60.

[0065] In one embodiment, the first response measure includes outputting a notification or alarm representing at least one of the following: detection of a rapid leak and / or a suggestion to evacuate. The control unit 13 may output a notification or alarm via the display unit 14 of the air conditioner 10 or a terminal device 60 to inform the user of the rapid leak by notification or alarm. In one example, the control unit 13 outputs an audio message via the speaker of the display unit 14 stating, "Refrigerant leak. Evacuate immediately." In another example, the control unit 13 notifies users who are not within the control range of the air conditioner 10 by having the terminal device 60 output a notification indicating the detection of a rapid leak via the communication unit 12. In another example, the control unit 13 sends the notification via the communication unit 12 to a server 50, which forwards the received notification to the management company of the air conditioner 10 or the building manager where the air conditioner 10 is installed.

[0066] In one embodiment, the air conditioner 10 includes at least one shut-off valve 17 provided in the refrigerant piping 21. In this embodiment, the first corresponding action includes operating the shut-off valve 17 to shut off the flow of refrigerant in the refrigerant piping 21.

[0067] Figure 6 is a schematic diagram of the refrigeration cycle 20 in Embodiment 1. Figure 6 shows the components related to the refrigeration cycle 20 in the air conditioner 10, and the black triangles indicate examples of the placement positions of the shut-off valve 17 (placement positions p5 to p7). The shut-off valve 17 shuts off the flow of refrigerant in the refrigerant piping 21. For example, the shut-off valve 17 may shut off the refrigerant to the indoor unit 30 or the outdoor unit 40, thereby shutting off the overall flow of refrigerant.

[0068] As shown in Figure 6, the shut-off valve 17 may be located on the indoor unit 30 (location p5), on the outdoor unit 40 (locations p7, p8), or between the indoor unit 30 and the outdoor unit 40 (location p6). The shut-off valve 17 may also be located near the compressor 22 (for example, locations p6, p7). Furthermore, the shut-off valve 17 may be located on the outside of the housing of the indoor unit 30 or the outdoor unit 40 so that it can be inspected by an inspector in the event of a leak or other issue.

[0069] In one embodiment, the first countermeasure includes operating the indoor fan 31 of the indoor unit 30. The control unit 13 operates the indoor fan 31 to agitate the refrigerant gas and disperse it into the indoor air so that a flammable area is not formed by the leaked refrigerant gas. In other words, the control unit 13 reduces the concentration of the leaked refrigerant by operating the indoor fan 31, thereby preventing ignition.

[0070] The control unit 13 may execute multiple first response measures in response to the detection of a rapid leak. In one embodiment, the control unit 13 selects an appropriate first response measure based on the state of refrigerant leakage or the amount of refrigerant loss. For example, the storage unit 11 stores a comparison table between the leakage state or amount of refrigerant loss and the first response measure to be taken. The control unit 13 determines the first response measure to be taken by comparing the comparison table with the leakage state to be determined or the detected amount of refrigerant loss.

[0071] According to the refrigerant leak detection method and air conditioner 10 described above, rapid leakage of flammable refrigerant can be detected. Furthermore, since appropriate first response measures can be taken in response to the detection of rapid leakage, safety regarding the use of flammable refrigerants can be enhanced.

[0072] As a result, the control unit 13 of the air conditioner 10 completes the process of detecting a rapid refrigerant leak. The control unit 13 may periodically repeat steps S110 to S130.

[0073] In one embodiment, the air conditioner 10 has a program used to perform the refrigerant leak detection method described above. The program causes the control unit 13 of the air conditioner 10 to perform the refrigerant leak detection method.

[0074] In one embodiment, the air conditioner 10 has a non-temporary, computer-readable storage medium in which a computer program is stored. The refrigerant leak detection method of the present disclosure is performed when the computer program is executed by a processor. The storage medium may be the same as the storage unit 11 of the air conditioner 10, may be included in the storage unit 11, or may be a different component from the storage unit 11.

[0075] Embodiment 2 <Detection of minute refrigerant leaks> In Embodiment 2, the refrigerant leak detection method and the air conditioner 10 detect leaks by using a pressure sensor 15 and a gas sensor 16 in combination. Furthermore, in Embodiment 2, the refrigerant leak detection method and the air conditioner 10 can also detect minute leaks of refrigerant (also known as slow leaks).

[0076] In this disclosure, a minute leak of refrigerant refers to a leak that progresses at a leak rate below or less than a predetermined value. For example, a refrigerant leak progressing at a leak rate of less than 7.5 kg / h is determined to be a minute leak.

[0077] In Embodiment 2, the air conditioner 10 further includes at least one gas sensor 16 (refrigerant sensor) (Figure 1). The gas sensor 16 is a sensor for detecting the refrigerant flowing through the refrigerant piping 21, and may be of the semiconductor type, catalytic combustion type, electrochemical type, optical type including non-dispersive infrared (NDIR) type, etc. Generally, the gas sensor 16 is located on the outside of the refrigerant piping 21, and may be located on the indoor unit 30 or on the outdoor unit 40. If it is desired to detect indoor leaks that pose a relatively high risk, the gas sensor 16 is located on the indoor unit 30.

[0078] As described above, the gas sensor 16 can detect the presence of leaked refrigerant, but it cannot detect the rate of refrigerant leakage. Therefore, even if refrigerant is detected by the gas sensor 16, it is not possible to distinguish whether it is a rapid leak or a minute leak. Herein, the refrigerant leak detection method and the air conditioner 10 determine whether it is a rapid leak or a minute leak by combining the pressure sensor 15 and the gas sensor 16.

[0079] Figure 7 is a flowchart of an example of a refrigerant leak detection method in Embodiment 2. The refrigerant leak detection method shown in Figure 7 includes steps S110, S120, S130A, S130B, and S210 to S230. Steps S110 and S120 in Figure 7 are the same as steps S110 and S120 in Figure 3, and the details are omitted here. In Embodiment 2, the above-mentioned step S130 includes steps S130A and S130B shown in Figure 7.

[0080] In Figure 7, the control unit 13 acquires pressure information and determines whether the amount of pressure drop of the refrigerant is greater than the change threshold (steps S110 and S120). Based on the determination result in step S120, the control unit 13 then determines whether the refrigerant is leaking rapidly (step S130A). If the determination result is that the amount of pressure drop is greater than the change threshold, the control unit 13 detects rapid refrigerant leakage (step S130B).

[0081] On the other hand, if the pressure drop is determined to be less than the change threshold, that is, if the pressure sensor 15 has not detected a rapid leak, the control unit 13 further determines whether or not the gas sensor 16 has detected refrigerant (step S210).

[0082] When the gas sensor 16 detects refrigerant, the control unit 13 detects a small leak of refrigerant (step S220). In this case, although refrigerant is leaking from the refrigerant piping 21 located in the indoor unit 30, the leakage rate is slower than the rate at which ignition could occur, so the possibility of ignition is low and the situation is relatively safe.

[0083] When a small leak of refrigerant is detected, the control unit 13 takes a second response measure in response to the detection of the small leak (step S230). Since a small leak is a relatively safe situation compared to a rapid leak, the second response measure does not have to include outputting an alarm instructing immediate evacuation or operating the shut-off valve 17. Instead, the second response measure may include outputting at least one of the following: a notification indicating the detection of a small leak, a notification suggesting ventilation, and a notification suggesting repair of the air conditioner 10. The second response measure may also include operating the indoor fan 31.

[0084] On the other hand, if neither rapid leakage nor refrigerant is detected, the control unit 13 completes the refrigerant leak detection process. When the next processing cycle for refrigerant leak detection begins, the control unit 13 starts again from step S110.

[0085] Furthermore, if it is determined that both rapid leakage and refrigerant have been detected, the control unit 13 may execute step S140 (Figure 5) described above.

[0086] Figure 8 is a schematic diagram of the pressure change of the refrigerant when a minute leak occurs. When a minute leak of the refrigerant occurs, the temperature of the refrigerant decreases due to the latent heat of vaporization, and the pressure of the refrigerant gas gradually decreases. As can be seen by comparing Figure 4B and Figure 8, the pressure drop when a minute leak occurs is more gradual than the pressure drop when a rapid leak occurs, and the leakage rate when a minute leak occurs is relatively slow.

[0087] As described above, by using the pressure sensor 15 and the gas sensor 16 in combination, it is possible to detect both rapid and minute leaks of refrigerant. Furthermore, because it is possible to detect both rapid and minute leaks, different countermeasures can be taken depending on the situation.

[0088] Embodiment 3 <Detection of refrigerant leakage outside the room> In Embodiment 3, the refrigerant leak detection method and the air conditioner 10 detect leaks by using a pressure sensor 15 and a gas sensor 16 in combination. In Embodiment 3, the refrigerant leak detection method and the air conditioner 10 can further detect refrigerant leaks to the outside. In this disclosure, refrigerant leaks to the outside refer to leaks where the leak location is in the outdoor unit 40, or between the indoor unit 30 and the outdoor unit 40.

[0089] In Embodiment 3, similar to Embodiment 2, the air conditioner 10 further includes at least one gas sensor 16 (Figure 1).

[0090] Figure 9 is a flowchart of an example of a refrigerant leak detection method in Embodiment 3. The refrigerant leak detection method shown in Figure 9 includes steps S110 to S140 and steps S310 to S330. Steps S110 to S140 in Figure 9 are the same as steps S110 to S140 in Figure 5, and the details are omitted here.

[0091] In the embodiment shown in Figure 9, the gas sensor 16 is located in the indoor unit 30. The control unit 13 can determine whether or not refrigerant leakage is occurring from the refrigerant piping 21 located inside the indoor unit 30 using the gas sensor 16. In the embodiment shown in Figure 9, the control unit 13 detects rapid leakage using the pressure sensor 15 and further determines whether or not refrigerant has been detected using the gas sensor 16 (step S310). If rapid leakage is detected and refrigerant has not been detected by the gas sensor 16 located inside the indoor unit 30, the control unit 13 detects refrigerant leakage to the outside (step S320).

[0092] In this case, although the refrigerant is leaking rapidly, the leak is located outside. Outside, airflow is more likely than inside, and the leaked refrigerant is diluted by the atmosphere, making ignition less likely and the situation relatively safe.

[0093] When the control unit 13 detects an outdoor refrigerant leak, it performs a third response measure in response to the detection of the outdoor leak (step S330). Since an outdoor leak is a relatively safer situation compared to a rapid indoor leak, the third response measure does not necessarily have to include outputting an alarm instructing immediate evacuation or operating the shut-off valve 17. Instead, the third response measure may include outputting a notification indicating the detection of an outdoor leak or a notification suggesting the repair of the air conditioner 10. The third response measure may also include operating the outdoor fan 41.

[0094] On the other hand, if a rapid leak is detected and the gas sensor 16 located inside the indoor unit 30 detects refrigerant, it is understood that the rapid leak is occurring indoors. In this case, the control unit 13 executes step S140 described above and takes the first corrective action.

[0095] In another embodiment, the gas sensor 16 is located in the outdoor unit 40, or between the indoor unit 30 and the outdoor unit 40. In this embodiment, if rapid leakage is detected and the gas sensor 16 located inside the outdoor unit 40 detects refrigerant, the control unit 13 performs a third corrective action. If rapid leakage is detected and the gas sensor 16 located inside the outdoor unit 40 does not detect refrigerant, the control unit 13 performs a first corrective action.

[0096] As described above, by using the pressure sensor 15 and the gas sensor 16 in combination, rapid refrigerant leakage and outdoor leakage can be detected. Furthermore, different countermeasures can be taken depending on whether it is a rapid leak or an outdoor leak.

[0097] Furthermore, the system can detect the three types of leakage states described above—rapid leakage, minute leakage, and outdoor leakage—and combine the first to third response measures. For example, the memory unit 11 stores a comparison table of multiple leakage states and corresponding response measures. The control unit 13 determines the appropriate response measure by comparing the leak situation to be determined with the comparison table.

[0098] Furthermore, this disclosure also provides a computer program and storage medium for a refrigerant leak detection method for an air conditioner 10, corresponding to embodiments 2 and 3.

[0099] Embodiment 4 <Detection device and method for detecting refrigerant leaks thereof> In Embodiment 4, a rapid leak of flammable refrigerant from the air conditioner 10 can be detected by a detection device different from the air conditioner 10. For example, a server 50 or terminal device 60 that can acquire pressure information from the air conditioner 10 can detect a rapid leak based on the acquired pressure information.

[0100] Figure 10A is a block diagram showing an example of the schematic configuration of the detection device in Embodiment 4. In the embodiment shown in Figure 10A, the server 50 operates as a detection device. The server 50 shown in Figure 10A includes a storage unit 51, a communication unit 52, a control unit 53, and a display unit 54. The server 50 can communicate with the air conditioner 10 via the communication unit 52. In the embodiment shown in Figure 10A, the refrigerant leak detection method is performed not by the control unit 13 of the air conditioner 10, but by the control unit 53 of the server 50 acting as a detection device. Furthermore, the control unit 53 of the server 50 does not directly acquire pressure information from the pressure sensor 15 of the air conditioner 10, but indirectly acquires pressure information from the air conditioner 10 via the storage unit 51 or the communication unit 52.

[0101] Figure 10B is a block diagram showing another example of the schematic configuration of the detection device in Embodiment 4. In the embodiment shown in Figure 10B, the terminal device 60 operates as a detection device. The terminal device 60 shown in Figure 10B includes an associated application 61, a storage unit 62, a communication unit 63, a control unit 64, and a presentation unit 65. The terminal device 60 can communicate with the air conditioner 10 via the communication unit 63. In the embodiment shown in Figure 10B, the refrigerant leak detection method is performed not by the control unit 13 of the air conditioner 10, but by the control unit 64 of the terminal device 60 acting as a detection device. Furthermore, the control unit 64 of the terminal device 60 does not directly acquire pressure information from the pressure sensor 15 of the air conditioner 10, but indirectly acquires pressure information from the air conditioner 10 or the server 50 via the storage unit 62 or the communication unit 63.

[0102] Figure 11 is a flowchart of an example of a refrigerant leak detection method in Embodiment 4. The refrigerant leak detection method shown in Figure 11 is performed by a detection device and includes steps S410 to S430.

[0103] In the embodiment shown in Figure 11, the control unit of the detection device (for example, control unit 53 or control unit 64) acquires pressure information from a pressure sensor 15 located in the air conditioner 10 via a communication unit (for example, communication unit 52 or communication unit 63) (step S410). Then, based on the acquired pressure information, the control unit of the detection device determines whether the pressure change within a predetermined time is greater than a change threshold (step S420), and based on the determination result, detects a rapid leak of refrigerant (step S430). The processing in steps S420 and S430 is substantially the same as the processing in steps S120 and S130 in Figure 3, and the details are omitted here.

[0104] As a result, the detection device, which can communicate with the air conditioner 10, can obtain pressure information related to the refrigerant pressure in the refrigerant piping 21 of the air conditioner 10 from the air conditioner 10 via the internet or the like. With such a refrigerant leak detection method and detection device, it is possible to detect rapid leakage of flammable refrigerant and take appropriate first countermeasures in response to the detection of rapid leakage. Furthermore, the detection device can further perform the detection methods described in Embodiments 2 and 3 to detect minute leaks or outdoor leaks and take appropriate countermeasures according to different leakage conditions.

[0105] In one embodiment, the server 50 or terminal device 60, acting as a detection device, has a program used to execute the refrigerant leak detection method shown in Figure 11. This program causes the control unit 53 of the server 50 or the control unit 64 of the terminal device 60 to execute the refrigerant leak detection method.

[0106] In one embodiment, the server 50 or terminal device 60 as a detection device has a non-temporary computer-readable storage medium on which a computer program is stored. The refrigerant leak detection method of the present disclosure is performed when the computer program is executed by a processor. The storage medium may be the same as the storage unit 51 of the server 50 or the storage unit 62 of the terminal device 60, may be included in the storage unit 51 or the storage unit 62, or may be a different component from the storage unit 51 or the storage unit 62.

[0107] (Other embodiments) (Note) Based on the above description of embodiments, the following technologies are disclosed.

[0108] (Technical 1) An air conditioner that uses a flammable refrigerant, comprising: a refrigerant pipe through which the refrigerant flows; a pressure sensor provided in the refrigerant pipe and which acquires pressure information related to the pressure of the refrigerant in the refrigerant pipe; and a control unit which acquires the pressure information from the pressure sensor, determines whether the pressure change within a predetermined time is greater than a change threshold based on the pressure information, and detects rapid leakage of the refrigerant based on the determination result.

[0109] With such an air conditioner, it is possible to detect the rapid leakage of flammable refrigerant from the refrigerant piping of the air conditioner.

[0110] (Technical 2) The air conditioner according to Technical 1, wherein the change threshold is set based on at least one of the type of refrigerant, the internal volume of the refrigerant piping circuit, and the amount of refrigerant charged into the air conditioner.

[0111] Such change thresholds allow for more accurate detection of rapid refrigerant leaks.

[0112] (Technology 3) The air conditioner according to Technology 1 or 2, wherein the change threshold is set according to a leakage rate of 7.5 kg / h or more.

[0113] Such change thresholds allow for more accurate detection of rapid refrigerant leaks.

[0114] (Technical 4) The air conditioner according to any one of Technical 1 to 3, wherein the predetermined time is 30 seconds or less.

[0115] According to this predetermined time frame, rapid refrigerant leakage can be detected immediately.

[0116] (Technical 5) The air conditioner according to any one of Technical 1 to 4, wherein the control unit performs a first response measure in response to the detection of a rapid leak, and the first response measure includes outputting a notification or alarm representing at least one of the detection of a rapid leak and a suggestion to evacuate.

[0117] In this way, appropriate countermeasures can be taken in response to rapid refrigerant leakage.

[0118] (Technology 6) The air conditioner according to any one of Technologies 1 to 5, wherein the air conditioner includes a shut-off valve provided in the refrigerant piping, the control unit performs a first response measure in response to the detection of a rapid leak, and the first response measure includes operating the shut-off valve to shut off the flow of the refrigerant in the refrigerant piping.

[0119] In this way, appropriate countermeasures can be taken in response to rapid refrigerant leakage.

[0120] (Technical 7) The air conditioner according to any one of Technical 1 to 6, wherein the air conditioner includes an indoor fan, and the control unit performs a first response measure in response to the detection of a rapid leak, the first response measure including operating the indoor fan.

[0121] In this way, appropriate countermeasures can be taken in response to rapid refrigerant leakage.

[0122] (Technology 8) The air conditioner according to any one of Technologies 1 to 7, wherein the air conditioner includes an indoor unit and a gas sensor provided inside the indoor unit and outside the refrigerant piping for detecting the refrigerant, and the control unit, when it determines that the pressure sensor has not detected a rapid leak and the gas sensor has detected the refrigerant, detects a minute leak of the refrigerant and performs a second corrective action in response to the detection of the minute leak.

[0123] This method makes it possible to detect minute leaks of refrigerant. Furthermore, since it can detect both rapid and minute leaks, different countermeasures can be taken depending on the situation.

[0124] (Technical 9) The air conditioner according to Technical 8, wherein the second response measure includes outputting a notice or alarm representing at least one of the following: detection of a minute leak, a suggestion to discontinue use of the air conditioner and ventilate, and a suggestion to repair the air conditioner.

[0125] In this way, appropriate countermeasures can be taken depending on the minute leakage of refrigerant.

[0126] (Technical 10) The air conditioner according to any one of Technical 1 to 9, wherein the air conditioner includes an indoor unit and a gas sensor provided inside the indoor unit and outside the refrigerant piping for detecting the refrigerant, and the control unit, when it determines that it has detected a rapid leak by the pressure sensor and that it has not detected the refrigerant by the gas sensor, detects an outdoor leak of the refrigerant and performs a third countermeasure in response to the detection of an outdoor leak.

[0127] This method allows for the detection of refrigerant leakage outside the room. Furthermore, since it can detect both rapid leakage and leakage outside the room, different countermeasures can be taken depending on the situation.

[0128] (Technical 11) The air conditioner according to Technical 10, wherein the air conditioner includes an outdoor fan, and the third corresponding measure includes operating the outdoor fan.

[0129] In this way, appropriate countermeasures can be taken depending on the amount of refrigerant leaking outside the room.

[0130] (Technical 12) The air conditioner according to any one of Technical 1 to 11, wherein the air conditioner includes an indoor unit and an outdoor unit, and the pressure sensor is provided in the refrigerant piping in a portion located inside the indoor unit.

[0131] Such pressure sensors offer relatively high sensitivity for leak detection.

[0132] (Technical 13) The air conditioner according to Technical 12, wherein the air conditioner includes a refrigeration cycle, the refrigeration cycle includes the refrigerant piping, a compressor, and an indoor heat exchanger, and the pressure sensor is provided in the refrigerant piping in a portion located inside the indoor unit and between the indoor heat exchanger and the compressor.

[0133] In this way, pressure information of the refrigerant gas can be obtained whether the refrigeration cycle is performing a cooling cycle or a heating cycle.

[0134] (Technical 14) A detection device for detecting refrigerant leakage in an air conditioner, comprising: a communication unit that acquires pressure information related to the pressure of refrigerant flowing in the refrigerant piping of the air conditioner; and a control unit that determines, based on the pressure information, whether the pressure change within a predetermined time is greater than a change threshold, and detects rapid leakage of the refrigerant based on the determination result.

[0135] (Technical 15) A method for detecting refrigerant leakage in an air conditioner, comprising: a step of acquiring pressure information related to the pressure of refrigerant flowing in the refrigerant piping of the air conditioner using a pressure sensor provided in the refrigerant piping; a step of determining whether a pressure change within a predetermined time is greater than a change threshold based on the pressure information; and a step of detecting rapid leakage of the refrigerant based on the determination result.

[0136] (Technical 16) A method for detecting refrigerant leakage in an air conditioner, comprising: a step of acquiring pressure information related to the pressure of refrigerant flowing in the refrigerant piping of the air conditioner; a step of determining, based on the pressure information, whether or not a pressure change within a predetermined time is greater than a change threshold; and a step of detecting rapid leakage of the refrigerant based on the determination result.

[0137] (Technical 17) A program that causes an air conditioner to execute the refrigerant leak detection method described in Technical 15, or a detection device to execute the refrigerant leak detection method described in Technical 16.

[0138] (Technical 18) A non-temporary computer-readable storage medium in which a computer program is stored, wherein the refrigerant leak detection method described in Technical 15 or 16 is performed when the computer program is executed by a processor.

[0139] According to the above-described detection device, refrigerant leak detection method, program, or storage medium, it is possible to detect the rapid leakage of flammable refrigerant from the refrigerant piping of an air conditioner.

[0140] The above are merely specific embodiments of the Disclosure, and the scope of protection of the Disclosure is not limited thereto. The Disclosure includes, but is not limited to, the drawings and the specific embodiments described above. Various embodiments or examples disclosed can be combined without departing from the scope or spirit of the Disclosure. Any modifications that do not depart from the functional and structural principles of the Disclosure are within the scope of the claims. [Explanation of Symbols]

[0141] 10. Air conditioner 11 Storage section 12 Communications Department 13 Control Unit 14 Presentation part 15. Pressure Sensor 16 Gas Sensors 17 Shut-off valve 20 Refrigeration Cycles 21 Refrigerant Piping 22 Compressor 23 Expansion valve 24 Four-way valve 25 Indoor heat exchanger 26 Outdoor heat exchanger 30 Indoor unit 31 Indoor fan 40 Outdoor unit 41 Outdoor fan 50 servers 51 Storage section 52 Communications Department 53 Control Unit 54 Presentation section 60 Terminal devices 61 Related Applications 62 Storage section 63 Communications Department 64 Control Unit 65 Presentation section p1~p8 placement position D1-D3 period

Claims

1. An air conditioner that uses a flammable refrigerant, Refrigerant piping through which refrigerant flows, A pressure sensor is provided in the refrigerant piping and acquires pressure information related to the pressure of the refrigerant in the refrigerant piping. A control unit, The pressure information is acquired by the pressure sensor, Based on the aforementioned pressure information, it is determined whether the pressure change within a predetermined time is greater than the change threshold. Based on the judgment result, rapid leakage of the refrigerant is detected. The control unit and, including, Air conditioner.

2. The change threshold is set based on at least one of the following: the type of refrigerant, the internal volume of the refrigerant piping, and the amount of refrigerant charged in the air conditioner. The air conditioner according to claim 1.

3. The aforementioned change threshold is set according to a leakage rate of 7.5 kg / h or more. The air conditioner according to claim 1.

4. The predetermined time is 30 seconds or less. The air conditioner according to claim 1.

5. The control unit performs a first response measure in response to the detection of rapid leakage. The first response measure includes issuing a notification or alarm representing at least one of the following: detection of a rapid leak and / or a suggestion to evacuate. The air conditioner according to claim 1.

6. The air conditioner includes a shut-off valve provided in the refrigerant piping. The control unit performs a first response measure in response to the detection of rapid leakage. The first countermeasure includes operating the shut-off valve to block the flow of the refrigerant in the refrigerant piping. The air conditioner according to claim 1.

7. The air conditioner includes an indoor fan, The control unit performs a first response measure in response to the detection of rapid leakage. The first countermeasure includes operating the indoor fan, The air conditioner according to claim 1.

8. The aforementioned air conditioner is Indoor unit and A gas sensor for detecting the refrigerant is provided inside the indoor unit and outside the refrigerant piping, Includes, The control unit, If the pressure sensor does not detect a rapid leak, and the gas sensor determines that the refrigerant has been detected, then a minute leak of the refrigerant is detected. In response to the detection of a minute leak, the second response measure will be taken. The air conditioner according to claim 1.

9. The second response measure includes outputting a notification or alarm indicating at least one of the following: detection of a minute leak, a suggestion to discontinue use of the air conditioner and ventilate, and a suggestion to repair the air conditioner. The air conditioner according to claim 8.

10. The aforementioned air conditioner is Indoor unit and A gas sensor for detecting the refrigerant is provided inside the indoor unit and outside the refrigerant piping, Includes, The control unit, If the pressure sensor detects a rapid leak and the gas sensor determines that the refrigerant is not detected, then the outdoor leak of the refrigerant is detected. In response to the detection of an outdoor leak, the third response measure will be taken. The air conditioner according to claim 1.

11. The aforementioned air conditioner includes an outdoor fan, The third countermeasure includes operating the outdoor fan, The air conditioner according to claim 10.

12. The aforementioned air conditioner includes an indoor unit and an outdoor unit. The pressure sensor is provided in the refrigerant piping in the portion located inside the indoor unit. The air conditioner according to claim 1.

13. The aforementioned air conditioner includes a refrigeration cycle, The refrigeration cycle includes the refrigerant piping, a compressor, and an indoor heat exchanger. The pressure sensor is located in the refrigerant piping, specifically in the portion located inside the indoor unit, and between the indoor heat exchanger and the compressor. The air conditioner according to claim 12.

14. A detection device for detecting refrigerant leaks in an air conditioner, A communication unit that acquires pressure information related to the pressure of the refrigerant flowing through the refrigerant piping of the air conditioner, A control unit, which determines whether the pressure change within a predetermined time is greater than a change threshold based on the pressure information, and detects rapid leakage of the refrigerant based on the determination result, including, Detection device.

15. A detection method for detecting refrigerant leaks in an air conditioner, The steps include: obtaining pressure information related to the pressure of the refrigerant flowing through the refrigerant piping of the air conditioner using a pressure sensor installed in the refrigerant piping of the air conditioner; Based on the aforementioned pressure information, the step of determining whether the pressure change within a predetermined time is greater than a change threshold, Based on the judgment result, a step of detecting the rapid leakage of the refrigerant, including, Refrigerant leak detection method.

16. A detection method for detecting refrigerant leaks in an air conditioner, The steps include obtaining pressure information related to the pressure of the refrigerant flowing through the refrigerant piping of the air conditioner, Based on the aforementioned pressure information, the step of determining whether the pressure change within a predetermined time is greater than a change threshold, Based on the judgment result, a step of detecting the rapid leakage of the refrigerant, including, Refrigerant leak detection method.

17. A program that causes an air conditioner to execute the refrigerant leak detection method described in claim 15, or a detection device to execute the refrigerant leak detection method described in claim 16.

18. A non-temporary, computer-readable storage medium on which computer programs are stored, The refrigerant leak detection method according to claim 15 or 16 is performed when the computer program is executed by the processor. A non-temporary, computer-readable storage medium.

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