A multi-connected air conditioning system

Abstract

This application discloses a multi-split air conditioning system, relating to the field of home appliance technology, which allows for more thorough recovery of leaked refrigerant. The multi-split air conditioning system includes: an outdoor unit, comprising a compressor, a four-way valve, an outdoor heat exchanger, and an outdoor expansion valve connected in sequence; an indoor unit, comprising multiple indoor units connected in parallel, each indoor unit including an indoor heat exchanger and an indoor expansion valve; and a refrigerant recovery device, comprising: a first solenoid valve, a second solenoid valve, a third solenoid valve, and a liquid receiver tank; wherein, the first end of the first solenoid valve is connected to the outdoor expansion valve via a pipeline, and the second end of the first solenoid valve is connected to the first opening of the liquid receiver tank; the two ports of the second solenoid valve are respectively connected to the second opening of the liquid receiver tank and the indoor expansion valve in each indoor unit; the first end of the third solenoid valve is connected to the outdoor expansion valve via a pipeline, and the second end of the third solenoid valve is connected to the indoor expansion valve in each indoor unit via a pipeline.

Description

Technical Field

[0001] This application relates to the field of home appliance technology, and in particular to a multi-split air conditioning system. Background Technology

[0002] With economic and social development, air conditioning is becoming increasingly widely used in various places such as entertainment, homes, and workplaces. When multiple small areas within the same region require air conditioning, multi-split air conditioning systems, consisting of one outdoor unit and multiple indoor units, are often used to regulate the room temperature in multiple areas in order to save energy. During the operation of a multi-split air conditioning system, heat transfer tubes (such as copper or aluminum tubes) are used on the heat exchanger for heat transfer. However, the heat transfer tubes are exposed to the outdoor environment for extended periods and may corrode, potentially causing refrigerant leakage.

[0003] To avoid the risks associated with refrigerant leaks, related technologies add a pair of electronic expansion valves to the inlet and outlet of each indoor unit in a multi-split air conditioning system to prevent leaked refrigerant from flowing into the indoor environment. However, with these technologies, the leaked refrigerant cannot be completely recovered and may be discharged into the outdoor environment, causing environmental pollution. Summary of the Invention

[0004] This application provides a multi-split air conditioning system that allows for more thorough recovery of leaked refrigerant, thereby improving the environmental friendliness of the multi-split air conditioning system.

[0005] In a first aspect, embodiments of this application provide a multi-split air conditioning system, comprising: an outdoor unit, the outdoor unit including a compressor, a four-way valve, an outdoor heat exchanger, and an outdoor expansion valve connected in sequence; an indoor unit, the indoor unit including multiple indoor units connected in parallel, each indoor unit including an indoor heat exchanger and an indoor expansion valve; and a refrigerant recovery device, the refrigerant recovery device including: a first solenoid valve, a second solenoid valve, a third solenoid valve, and a liquid receiver; wherein, a first end of the first solenoid valve is connected to the outdoor expansion valve via a pipeline, and a second end of the first solenoid valve is connected to a first opening of the liquid receiver; a first end of the second solenoid valve is connected to a second opening of the liquid receiver, and a second end of the second solenoid valve is connected to the indoor expansion valve in each indoor unit via a pipeline; a first end of the third solenoid valve is connected to the outdoor expansion valve via a pipeline, and a second end of the third solenoid valve is connected to the indoor expansion valve in each indoor unit via a pipeline.

[0006] The technical solution provided in this application provides at least the following beneficial effects: In a multi-split air conditioning system, a refrigerant recovery device is installed between the outdoor unit and the indoor unit. When refrigerant leakage occurs, the direction of refrigerant flow in the multi-split air conditioning system is controlled by adjusting the opening and closing states of the first, second, and third solenoid valves in the refrigerant recovery device, based on the operating mode to be entered by the outdoor and indoor units. This guides the refrigerant in the multi-split air conditioning system into the liquid storage tank of the refrigerant recovery device, achieving complete recovery of the leaked refrigerant. This avoids the problem of refrigerant being discharged into the outdoor environment and causing environmental pollution, thereby improving the environmental friendliness of the multi-split air conditioning system.

[0007] In some embodiments, the multi-split air conditioning system has multiple operating modes, including a cooling mode, a heating mode, a first refrigerant recovery mode, and a second refrigerant recovery mode. When the multi-split air conditioning system is in cooling mode, the outdoor heat exchanger functions as a condenser, the indoor heat exchanger functions as an evaporator, and the first solenoid valve is closed, the second solenoid valve is closed, and the third solenoid valve is open. When the multi-split air conditioning system is in heating mode, the outdoor heat exchanger functions as an evaporator, the indoor heat exchanger functions as a condenser, and the first solenoid valve is closed. In the first refrigerant recovery mode, the outdoor heat exchanger functions as a condenser, and the indoor heat exchanger functions as an evaporator. The first solenoid valve is open, the second solenoid valve is closed, and the third solenoid valve is closed. In the second refrigerant recovery mode, the outdoor heat exchanger functions as an evaporator, and the indoor heat exchanger functions as a condenser. The first solenoid valve is closed, the second solenoid valve is open, and the third solenoid valve is closed.

[0008] Based on this, multi-split air conditioning systems can provide operating modes corresponding to different scenarios. Specifically, when cooling is needed (e.g., when the room temperature is too high), the multi-split air conditioning system switches to cooling mode to lower the indoor temperature. When heating is needed (e.g., when the room temperature is too low), the multi-split air conditioning system switches to heating mode to raise the indoor temperature. When it is necessary to recover leaked refrigerant from the indoor unit, the multi-split air conditioning system can be switched to the first refrigerant recovery mode to recover the leaked refrigerant through the refrigerant recovery device. When it is necessary to recover leaked refrigerant from the outdoor unit, the multi-split air conditioning system can be switched to the second refrigerant recovery mode to recover the leaked refrigerant through the refrigerant recovery device.

[0009] In some embodiments, each indoor unit further includes an indoor refrigerant leak detection device; the multi-split air conditioning system further includes: a controller electrically connected to the indoor refrigerant leak detection device in each indoor unit; the controller is configured to: acquire the detection result of each indoor refrigerant leak detection device, the detection result of one indoor refrigerant leak detection device being used to indicate whether a refrigerant leak has occurred in the indoor unit where the refrigerant leak detection device is located; determine, based on the detection result of each indoor refrigerant leak detection device, whether there is an indoor unit in the indoor unit group that has experienced a refrigerant leak; if so, control the multi-split air conditioning system to operate in a first refrigerant recovery mode.

[0010] In this way, the multi-split air conditioning system can identify the indoor unit experiencing a refrigerant leak based on the detection results of the indoor refrigerant leak detection device. When a refrigerant leak is detected in an indoor unit, the system switches to the first refrigerant recovery mode, recovering the leaked refrigerant to the refrigerant recovery device. This prevents refrigerant leaks from the indoor unit into the indoor environment, thus improving the safety of the multi-split air conditioning system. Furthermore, by recovering the refrigerant through the refrigerant recovery device, the amount of refrigerant emitted from the outdoor unit into the outdoor environment is significantly reduced, improving the environmental friendliness of the multi-split air conditioning system.

[0011] In some embodiments, the outdoor unit further includes an outdoor refrigerant leak detection device, and the controller is electrically connected to the outdoor refrigerant leak detection device of the outdoor unit; the controller is configured to: acquire the detection result of the outdoor refrigerant leak detection device, the detection result of the outdoor refrigerant leak detection device being used to indicate whether a refrigerant leak has occurred in the outdoor unit; if the detection result of the outdoor refrigerant leak detection device indicates that a refrigerant leak has occurred in the outdoor unit, control the multi-split air conditioning system to operate a second refrigerant recovery mode.

[0012] In this way, the multi-split air conditioning system can determine whether a refrigerant leak has occurred in the outdoor unit based on the detection results of the outdoor refrigerant leak detection device. If a refrigerant leak occurs in the outdoor unit, the system switches to a second refrigerant recovery mode to recover the leaked refrigerant into the refrigerant recovery device. This significantly reduces the amount of refrigerant emitted into the outdoor environment, improving the environmental friendliness of the multi-split air conditioning system.

[0013] In some embodiments, the controller is further configured to: close the indoor expansion valve in the indoor unit where refrigerant leakage occurs when the multi-split air conditioning system is operating in a first refrigerant recovery mode; and control the outdoor expansion valve to its maximum opening value when the multi-split air conditioning system is operating in a second refrigerant recovery mode.

[0014] In this embodiment, when the multi-split air conditioning system is operating in the first refrigerant recovery mode, the indoor expansion valve in the indoor unit where refrigerant leakage has occurred is closed to prevent refrigerant from continuing to enter the leaking indoor unit. This avoids refrigerant leakage from the leaking indoor unit into the indoor environment, thereby ensuring safe use of the multi-split air conditioning system by the user. When the multi-split air conditioning system is operating in the second refrigerant recovery mode, the outdoor expansion valve is controlled to its maximum opening value, allowing the refrigerant in the pipe connected to the outdoor expansion valve to pass through the outdoor and indoor units more quickly and be recovered to the refrigerant recovery device. This improves the recovery speed of refrigerant leaking from the outdoor unit and ensures the refrigerant recovery efficiency of the multi-split air conditioning system.

[0015] In some embodiments, the refrigerant recovery device further includes a fourth solenoid valve, the first end of which is connected to a four-way valve via a pipeline, and the second end of which is connected to an indoor heat exchanger in each indoor unit via a pipeline; when the multi-split air conditioning system is in cooling mode, heating mode, first refrigerant recovery mode or second refrigerant recovery mode, the fourth solenoid valve is in the open state.

[0016] Therefore, when the multi-split air conditioning system is running in any of the following modes—cooling mode, heating mode, first refrigerant recovery mode, or second refrigerant recovery mode—the fourth solenoid valve is kept open to ensure that the refrigerant can circulate in the corresponding pipeline.

[0017] In some embodiments, the controller is further configured to: in the first refrigerant recovery mode and the second refrigerant recovery mode, control the fourth solenoid valve to close when the refrigerant recovery stop condition is met; wherein the refrigerant recovery stop condition includes one or more of the following: the duration for which the multi-split air conditioning system operates in the first refrigerant recovery mode or the second refrigerant recovery mode reaches a preset duration; or, the pressure of the refrigerant entering the compressor is within a preset pressure range.

[0018] Based on this, by setting refrigerant recovery stop conditions, the timing for ending refrigerant recovery can be determined so that refrigerant is recovered when the amount of refrigerant in the piping of the multi-split air conditioning system is within a reasonable range. This avoids the multi-split air conditioning system from still executing the first or second refrigerant recovery mode when there is no refrigerant in the piping, which could cause abnormalities or damage to the multi-split air conditioning system, thereby improving the safety and service life of the multi-split air conditioning system.

[0019] In some embodiments, the refrigerant recovery device further includes a fifth solenoid valve, the first end of which is connected to the second end of the fourth solenoid valve via a pipeline, and the second end of which is connected to the indoor heat exchanger in each indoor unit via a pipeline; when the multi-split air conditioning system is in cooling mode, heating mode, first refrigerant recovery mode or second refrigerant recovery mode, the fifth solenoid valve is in the open state.

[0020] Therefore, when the multi-split air conditioning system is running in any of the following modes—cooling mode, heating mode, first refrigerant recovery mode, or second refrigerant recovery mode—the fifth solenoid valve is kept open to ensure that the refrigerant can circulate in the corresponding pipeline.

[0021] In some embodiments, the controller is further configured to: in the first refrigerant recovery mode or the second refrigerant recovery mode, control the fifth solenoid valve to close when the refrigerant recovery stop condition is met; wherein the refrigerant recovery stop condition includes one or more of the following: the duration of the multi-split air conditioning system operating in the first refrigerant recovery mode or the second refrigerant recovery mode has reached a preset duration; or, the pressure of the refrigerant entering the compressor is within a preset pressure range.

[0022] In this embodiment, the indoor expansion valve corresponding to the indoor unit experiencing refrigerant leakage is in a closed state. After refrigerant recovery is completed, the fourth and fifth solenoid valves are closed, allowing the indoor units experiencing refrigerant leakage to be freely separated from the refrigerant recovery device and the outdoor unit. This facilitates the replacement of the indoor unit experiencing refrigerant leakage without being affected by the refrigerant recovery device and the outdoor unit, improving the convenience of installing or replacing the indoor unit.

[0023] In some embodiments, the refrigerant recovery device further includes an expansion valve; wherein, the first end of the expansion valve is connected to the second end of the fourth solenoid valve via a pipeline, and the second end of the expansion valve is connected to the second end of the first solenoid valve via a pipeline; or, the first end of the expansion valve is connected to the second end of the fourth solenoid valve via a pipeline, and the second end of the expansion valve is connected to the third opening of the liquid storage tank via a pipeline.

[0024] In this embodiment, during refrigerant recovery, as the amount of refrigerant circulating within the multi-split air conditioning system decreases and the low pressure of the system approaches the preset pressure range (typically referring to the atmospheric pressure of the environment in which the system operates), the compressor discharge temperature increases, potentially affecting compressor reliability. Therefore, an expansion valve is added between the first and fourth solenoid valves, or between the fourth solenoid valve and the receiver-receiver tank. During refrigerant recovery, this expansion valve is opened, allowing a portion of the refrigerant to bypass the compressor and reduce its discharge temperature, thereby lowering the compressor's overall temperature and ensuring its reliability during refrigerant recovery.

[0025] Furthermore, during refrigerant recovery, the refrigerant entering the receiver tank may be a two-phase refrigerant consisting of both gaseous and liquid states. When the refrigerant entering the receiver tank is a two-phase refrigerant, its lower average density reduces the amount of refrigerant stored in the tank, thus affecting the refrigerant recovery efficiency. Therefore, during refrigerant recovery, the expansion valve is opened to allow gaseous refrigerant to bypass the process and improve the overall recovery efficiency.

[0026] In some embodiments, the refrigerant recovery device further includes: a first shut-off valve, which is disposed on the pipeline between the four-way valve and the fourth solenoid valve, with a first end of the first shut-off valve connected to the four-way valve via a pipeline and a second end of the first shut-off valve connected to the first end of the fourth solenoid valve via a pipeline; a second shut-off valve, which is disposed on the pipeline between the fourth solenoid valve and the indoor heat exchanger, with a first end of the second shut-off valve connected to the second end of the fourth solenoid valve via a pipeline and a second end of the second shut-off valve connected to the indoor heat exchanger in each indoor unit via a pipeline; a third shut-off valve, which is disposed on the pipeline between the outdoor expansion valve and the first solenoid valve, with a first end of the third shut-off valve connected to the outdoor expansion valve via a pipeline and a second end of the third shut-off valve connected to the first end of the first solenoid valve via a pipeline; and a fourth shut-off valve, which is disposed on the pipeline between the second solenoid valve and the indoor heat exchanger, with a first end of the fourth shut-off valve connected to the second end of the second solenoid valve via a pipeline and a second end of the fourth shut-off valve connected to the indoor expansion valve in each indoor unit via a pipeline.

[0027] In this embodiment, during the operation of the multi-split air conditioning system in either the first or second refrigerant recovery mode, the first, second, third, and fourth shut-off valves are in the open state. After the first or second refrigerant recovery mode operation is completed, the first, second, and third solenoid valves are in the closed state, and simultaneously, the first, second, third, and fourth shut-off valves are also in the closed state to better prevent the flow of refrigerant in the corresponding pipes of the shut-off valves.

[0028] In some embodiments, the outdoor unit further includes: a fifth shut-off valve, which is disposed on the pipeline between the four-way valve and the first shut-off valve, with the first end of the fifth shut-off valve connected to the four-way valve via a pipeline and the second end of the fifth shut-off valve connected to the first end of the first shut-off valve via a pipeline; and a sixth shut-off valve, which is disposed on the pipeline between the outdoor expansion valve and the third shut-off valve, with the first end of the sixth shut-off valve connected to the outdoor expansion valve via a pipeline and the second end of the sixth shut-off valve connected to the first end of the third shut-off valve via a pipeline.

[0029] In this embodiment, during the operation of the multi-split air conditioning system in either the first or second refrigerant recovery mode, the fifth and sixth shut-off valves are in the open state. After the first or second refrigerant recovery mode operation is completed, the fifth and sixth solenoid valves are in the closed state to better prevent the flow of refrigerant in the pipeline corresponding to the shut-off valves.

[0030] In some embodiments, the outdoor unit further includes: a sixth solenoid valve, which is disposed on the pipeline between the four-way valve and the fifth shut-off valve, wherein the first end of the sixth solenoid valve is connected to the four-way valve through a pipeline, and the second end of the sixth solenoid valve is connected to the first end of the fifth shut-off valve through a pipeline; and a seventh solenoid valve, which is disposed on the pipeline between the outdoor expansion valve and the sixth shut-off valve, wherein the first end of the seventh solenoid valve is connected to the outdoor expansion valve through a pipeline, and the second end of the seventh solenoid valve is connected to the first end of the sixth shut-off valve through a pipeline.

[0031] Based on the aforementioned sixth and seventh solenoid valves, after refrigerant recovery is completed, the sixth and seventh solenoid valves are closed to allow the outdoor unit to be freely separated from the refrigerant recovery device and the indoor unit. This ensures that the outdoor unit is not affected by the refrigerant recovery device and the indoor unit during the replacement process, thus improving the convenience of installing or replacing the outdoor unit.

[0032] Secondly, embodiments of this application provide a control method for a multi-split air conditioning system, applied to the multi-split air conditioning system of the first aspect. The method includes: when an indoor unit with refrigerant leakage is detected, controlling the multi-split air conditioning system to operate in a first refrigerant recovery mode; and when an outdoor unit with refrigerant leakage is detected, controlling the multi-split air conditioning system to operate in a second refrigerant recovery mode. In the first refrigerant recovery mode, the outdoor heat exchanger functions as a condenser, the indoor heat exchanger functions as an evaporator, and the first solenoid valve is open, the second solenoid valve is closed, and the third solenoid valve is closed. In the second refrigerant recovery mode, the outdoor heat exchanger functions as an evaporator, the indoor heat exchanger functions as a condenser, and the first solenoid valve is closed, the second solenoid valve is open, and the third solenoid valve is closed.

[0033] In some embodiments, each indoor unit further includes an indoor refrigerant leak detection device; the detection result of each indoor refrigerant leak detection device is acquired, and the detection result of one indoor refrigerant leak detection device is used to indicate whether a refrigerant leak has occurred in the indoor unit where the refrigerant leak detection device is located; based on the detection result of each indoor refrigerant leak detection device, it is determined whether there is an indoor unit in the indoor unit group that has a refrigerant leak; if so, the multi-split air conditioning system is controlled to operate in a first refrigerant recovery mode.

[0034] In some embodiments, the outdoor unit further includes an outdoor refrigerant leak detection device; the detection result of the outdoor refrigerant leak detection device is obtained, and the detection result of the outdoor refrigerant leak detection device is used to indicate whether the outdoor unit has a refrigerant leak; if the detection result of the outdoor refrigerant leak detection device indicates that the outdoor unit has a refrigerant leak, the multi-split air conditioning system is controlled to operate in a second refrigerant recovery mode.

[0035] In some embodiments, when the multi-split air conditioning system is operating in the first refrigerant recovery mode, the indoor expansion valve in the indoor unit where refrigerant leakage has occurred is closed; when the multi-split air conditioning system is operating in the second refrigerant recovery mode, the outdoor expansion valve is controlled to be at its maximum opening value.

[0036] In some embodiments, the refrigerant recovery device further includes a fourth solenoid valve, the first end of which is connected to a four-way valve via a pipeline, and the second end of which is connected to an indoor heat exchanger in each indoor unit via a pipeline; when the multi-split air conditioning system is in cooling mode, heating mode, first refrigerant recovery mode or second refrigerant recovery mode, the fourth solenoid valve is controlled to be in the open state.

[0037] In some embodiments, when the duration of operation of the first refrigerant recovery mode or the second refrigerant recovery mode in the multi-split air conditioning system reaches a preset duration; or when the pressure of the refrigerant entering the compressor is within a preset pressure range, the fourth solenoid valve is controlled to close.

[0038] In some embodiments, the refrigerant recovery device further includes a fifth solenoid valve, the first end of which is connected to the second end of the fourth solenoid valve via a pipeline, and the second end of which is connected to the indoor heat exchanger in each indoor unit via a pipeline; when the multi-split air conditioning system is in cooling mode, heating mode, first refrigerant recovery mode or second refrigerant recovery mode, the fifth solenoid valve is controlled to be in the open state.

[0039] In some embodiments, when the duration of the multi-split air conditioning system operating in the first refrigerant recovery mode or the second refrigerant recovery mode reaches a preset duration; or when the pressure of the refrigerant entering the compressor is within a preset pressure range, the fifth solenoid valve is controlled to close.

[0040] In some embodiments, when the duration of the multi-split air conditioning system operating in the first refrigerant recovery mode or the second refrigerant recovery mode reaches a preset duration; or when the pressure of the refrigerant entering the compressor is within a preset pressure range, the multi-split air conditioning system is controlled to stop operating.

[0041] Thirdly, embodiments of this application provide a control device for a multi-split air conditioning system, comprising: one or more processors; one or more memories; wherein the one or more memories are used to store computer program code, the computer program code including computer instructions, and when the one or more processors execute the computer instructions, the controller executes the methods provided in the second aspect and possible implementations.

[0042] Fourthly, embodiments of this application provide a computer-readable storage medium including computer instructions that, when executed on a computer, cause the computer to perform the methods provided in the second aspect and possible implementations.

[0043] Fifthly, embodiments of this application provide a computer program product containing computer instructions that, when executed on a computer, cause the computer to perform the methods provided in the second aspect and possible implementations described above.

[0044] It should be noted that the aforementioned computer instructions may be stored, in whole or in part, on a computer-readable storage medium. This computer-readable storage medium may be packaged together with the controller's processor, or it may be packaged separately from the controller's processor; this application does not impose any limitations on this.

[0045] The beneficial effects described in aspects two through five of this application can be referred to the analysis of the beneficial effects of aspect one, and will not be repeated here. Attached Figure Description

[0046] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of the present invention and do not constitute a limitation on the technical solutions of the present invention.

[0047] Figure 1 This is a schematic diagram of the structure of a multi-split air conditioning system according to some embodiments;

[0048] Figure 2 This is a schematic diagram illustrating the refrigerant circulation principle of a multi-split air conditioning system according to some embodiments;

[0049] Figure 3 This is a schematic diagram illustrating the refrigerant circulation principle of another multi-split air conditioning system according to some embodiments;

[0050] Figure 4 This is a schematic diagram illustrating the refrigerant circulation principle of another multi-split air conditioning system according to some embodiments;

[0051] Figure 5 This is a schematic diagram illustrating the refrigerant circulation principle of another multi-split air conditioning system according to some embodiments;

[0052] Figure 6 This is a schematic diagram of another multi-split air conditioning system according to some embodiments;

[0053] Figure 7 This is a schematic diagram of another multi-split air conditioning system according to some embodiments;

[0054] Figure 8 This is a schematic diagram of a control method for a multi-split air conditioning system according to some embodiments;

[0055] Figure 9This is a schematic diagram of the control process of a multi-split air conditioning system according to some embodiments;

[0056] Figure 10 This is a schematic diagram of the control process of another multi-split air conditioning system according to some embodiments;

[0057] Figure 11 This is a schematic diagram of the hardware structure of a controller according to some embodiments.

[0058] Figure reference numerals: 100 - Multi-split air conditioning system; 200 - Outdoor unit; 201 - Compressor; 202 - Four-way valve; 203 - Outdoor heat exchanger; 204 - Outdoor expansion valve; 205 - Gas-liquid separator; 206 - Oil separator; 207 - Oil return capillary tube; 208 - Outdoor check valve; 209 - First outdoor pressure sensor; 210 - Second outdoor pressure sensor; 211 - Fifth shut-off valve; 212 - Sixth shut-off valve; 213 - Sixth solenoid valve; 214 - Seventh solenoid valve; 215 - Outdoor fan; 300 - Indoor unit; 300A - First indoor unit; 300 B - Second indoor unit; 301A - First indoor heat exchanger; 302A - First indoor expansion valve; 303A - First indoor fan; 301B - Second indoor heat exchanger; 302B - Second indoor expansion valve; 303B - Second indoor fan; 400 - Refrigerant recovery device; 401 - First solenoid valve; 402 - Second solenoid valve; 403 - Third solenoid valve; 404 - Liquid receiver; 405 - Fourth solenoid valve; 406 - Fifth solenoid valve; 407 - First shut-off valve; 408 - Second shut-off valve; 409 - Third shut-off valve; 410 - Fourth shut-off valve; 411 - Expansion valve. Detailed Implementation

[0059] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0060] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0061] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, when describing pipelines, the terms "connected" and "linked" as used in this application have the meaning of establishing electrical connection. The specific meaning needs to be understood in conjunction with the context.

[0062] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and its other forms, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" are intended to indicate that the particular features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0063] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0064] As described in the background section, to avoid the risks associated with refrigerant leakage, related technologies add a pair of electronic expansion valves to the inlet and outlet of each indoor unit in a multi-split air conditioning system to prevent leaked refrigerant from flowing into the indoor environment. However, in the aforementioned related technologies, the leaked refrigerant cannot be completely recovered and may be discharged into the outdoor environment, causing environmental pollution.

[0065] To address this issue, this application provides a multi-split air conditioning system. In this system, a refrigerant recovery device is installed between the outdoor and indoor units. When a refrigerant leak occurs, the direction of refrigerant flow in the multi-split air conditioning system is controlled by adjusting the opening and closing states of three solenoid valves (first, second, and third) in the refrigerant recovery device, based on the desired operating mode of the outdoor and indoor units. This directs the refrigerant into the storage tank of the refrigerant recovery device, achieving complete recovery of the leaked refrigerant and preventing environmental pollution caused by refrigerant discharge into the outdoor environment. This improves the environmental friendliness of the multi-split air conditioning system.

[0066] To further describe the solution in this application, as follows: Figure 1 The diagram shown is a structural schematic of a multi-split air conditioning system provided in an embodiment of this application.

[0067] Reference Figure 1 The multi-split air conditioning system 100 includes an outdoor unit 200 and multiple indoor units (such as outdoor units 200 and indoor units 300) connected in parallel. Figure 1 The first indoor unit 300A, the second indoor unit 300B, and the refrigerant recovery device 400 are shown.

[0068] Outdoor unit 200

[0069] The outdoor unit 200 includes a compressor 201, a four-way valve 202, an outdoor heat exchanger 203, and an outdoor expansion valve 204 connected in sequence.

[0070] In some embodiments, one end of the outdoor heat exchanger 203 is connected to the compressor 201 via a four-way valve 202, and the other end is connected to the refrigerant recovery device 400. The outdoor heat exchanger 203 is used to facilitate heat exchange between the refrigerant flowing in the heat transfer tubes of the outdoor heat exchanger 203 and the outdoor air. The compressor 201 is positioned between the indoor heat exchanger and the outdoor heat exchanger 203 to provide power for the refrigerant circulation. Taking a refrigeration cycle as an example, the compressor 201 delivers compressed refrigerant to the outdoor heat exchanger 203 via the four-way valve 202.

[0071] Alternatively, the compressor 201 may be a variable capacity inverter compressor 201 with inverter speed control.

[0072] In some embodiments, such as Figure 1 The four-way valve 202 has four ports (i.e., port C, port D, port S, and port E) connected to the discharge port of compressor 201, outdoor heat exchanger 203, compressor 201 suction port, and the indoor heat exchangers of each indoor unit, respectively. The four-way valve 202 is used to switch between cooling and heating modes by changing the flow direction of refrigerant in the system piping.

[0073] In some embodiments, the outdoor unit 200 further includes an outdoor fan 215 that generates an airflow through the outdoor heat exchanger 203 to promote heat exchange between the refrigerant flowing in the heat transfer tubes of the outdoor heat exchanger 203 and the outdoor air.

[0074] In some embodiments, the outdoor unit 200 further includes an outdoor fan 215 motor (not shown) connected to the outdoor fan 215 for driving or changing the speed of the outdoor fan 215.

[0075] In some embodiments, the outdoor unit 200 further includes a gas-liquid separator 205, an oil separator 206, an oil return capillary tube 207, and an outdoor one-way valve 208.

[0076] In detail, such as Figure 1 As shown, the outlet of compressor 201 is connected to the first end of oil separator 206 via a pipeline. The second end of oil separator 206 is connected to outdoor check valve 208 via a pipeline. Outdoor check valve 208 is connected to four-way valve 202 via a pipeline. Four-way valve 202 is connected to outdoor heat exchanger 203 via a pipeline. Outdoor heat exchanger 203 is connected to outdoor expansion valve 204 via a pipeline. The third end of oil separator 206 is connected to the first opening of gas-liquid separator 205 via a pipeline; the second opening of gas-liquid separator 205 is connected to four-way valve 202 via a pipeline.

[0077] In some other embodiments, the outdoor unit 200 also includes an outdoor refrigerant leak detection device (not shown in the figure).

[0078] In some embodiments, the outdoor unit 200 further includes a first outdoor pressure sensor 209 and a second outdoor pressure sensor 210. The first outdoor pressure sensor 209 is located at the first port of the gas-liquid separator 205 and is used to detect the pressure of the refrigerant entering the compressor 201. The second outdoor pressure sensor 210 is located in the pipeline connected to the outdoor one-way valve 208 and the four-way valve 202 and is used to detect the pressure of the refrigerant flowing out of the compressor 201. Typically, the first outdoor pressure sensor 209 can be referred to as a low-pressure sensor or a high-pressure sensor, and there is no limitation in this regard.

[0079] Indoor unit 300

[0080] The indoor unit 300 includes: multiple indoor units connected in parallel, each indoor unit including an indoor heat exchanger and an indoor expansion valve.

[0081] In some embodiments, the indoor unit 300 further includes an indoor refrigerant leak detection device corresponding to each of the plurality of indoor units. The indoor refrigerant leak detection device (not shown in the figure) is used to detect whether a refrigerant leak has occurred in the corresponding indoor unit of the indoor unit 300. This indoor refrigerant leak detection device is commonly referred to as an indoor refrigerant leak detection sensor.

[0082] For example, the first indoor unit 300A includes: a first indoor heat exchanger 301A, a first indoor expansion valve 302A, and a first indoor refrigerant leak detection device.

[0083] In some embodiments, the first indoor unit 300A further includes a first indoor liquid pipe temperature sensor (not shown), a first indoor return air temperature sensor (not shown), and a first indoor fan 303A.

[0084] Another example is that the second indoor unit 300B includes: a second indoor heat exchanger 301B, a second indoor expansion valve 302B, and a second indoor refrigerant leak detection device.

[0085] In some embodiments, the second indoor unit 300B further includes a second indoor liquid pipe temperature sensor (not shown), a second indoor return air temperature sensor (not shown), and a second indoor fan 303B. The second indoor liquid pipe temperature sensor is used to detect the refrigerant temperature in the indoor unit's piping; the second indoor return air temperature sensor is used to detect the return air temperature of the indoor unit.

[0086] The functions and settings of each component of the indoor unit are explained in detail below.

[0087] In some embodiments, the first indoor heat exchanger 301A is used to exchange heat between the refrigerant flowing in the heat transfer tubes of the first indoor heat exchanger 301A and the indoor air.

[0088] In some embodiments, the first indoor expansion valve 302A is disposed between the first indoor heat exchanger 301A and the refrigerant recovery device 400, and has the function of expanding the refrigerant flowing through the first indoor expansion valve 302A to reduce pressure, and can be used to regulate the supply of refrigerant in the pipeline.

[0089] Optionally, the multi-split air conditioning system can be equipped with multiple first indoor expansion valves 302A, such as multiple electronic expansion valves. If the opening of the first indoor expansion valve 302A decreases, the flow resistance of the refrigerant through the first indoor expansion valve 302A increases. If the opening of the first indoor expansion valve 302A increases, the flow resistance of the refrigerant through the first indoor expansion valve 302A decreases. Thus, even if the states of other components in the circuit remain unchanged, the refrigerant flow rate to the first indoor heat exchanger 301A or the outdoor heat exchanger 203 will change when the opening of the first indoor expansion valve 302A changes. It should be noted that... Figure 1The number of indoor expansion valves and outdoor expansion valves 204 shown are merely examples, and this application does not impose any specific limitations on them.

[0090] In some embodiments, the first indoor fan 303A generates an airflow through the first indoor heat exchanger 301A to promote heat exchange between the refrigerant flowing in the heat transfer tubes of the first indoor heat exchanger 301A and the indoor air.

[0091] In some embodiments, the first indoor unit 300A further includes an indoor fan motor (not shown) connected to an indoor fan for driving or changing the speed of the indoor fan.

[0092] In some embodiments, the first indoor unit 300A further includes a plurality of capillary tubes (not shown in the figure) for reducing the refrigerant pressure in the pipes and depressurizing the high-pressure refrigerant delivered by the condenser before delivering it to the evaporator.

[0093] In some embodiments, the first indoor unit 300A further includes a humidity sensor (not shown) for detecting the relative humidity of the indoor air.

[0094] In some embodiments, the first indoor unit 300A further includes a dew point meter (not shown) for detecting the ambient dew point temperature near the indoor heat exchanger.

[0095] In some embodiments, the first indoor unit 300A further includes a display (not shown). The display is electrically connected to the controller. Optionally, the display is used to show the control panel of the multi-split air conditioning system; for example, the display may show the indoor temperature or the current operating mode. Optionally, the display is connected to the controller, allowing the user to perform operations and set programs on the control panel via the display. Optionally, the display also includes a pressure sensor or a temperature sensor, enabling the display to transmit user commands to the controller based on user gestures, such as pressing buttons, to achieve human-machine interaction. Optionally, the display may be a liquid crystal display (LCD) or an organic light-emitting diode (OLED) display. The specific type, size, and resolution of the display are not limited, but those skilled in the art will understand that the display can be modified in terms of performance and configuration as needed.

[0096] It should be noted that the number of indoor units mentioned above is only an example. The number of indoor units in the multi-split air conditioning system shown in this application can be two or more, and this application does not impose any restrictions on this.

[0097] 400 refrigerant recovery unit

[0098] The refrigerant recovery device 400 includes: a first solenoid valve 401, a second solenoid valve 402, a third solenoid valve 403, and a liquid storage tank 404.

[0099] The liquid storage tank 404 is used to store the refrigerant recovered by the multi-split air conditioning system in refrigerant recovery mode (i.e., first refrigerant recovery mode and second refrigerant recovery mode).

[0100] In this system, the first end of the first solenoid valve 401 is connected to the outdoor expansion valve 204 via a pipeline, and the second end of the first solenoid valve 401 is connected to the first opening of the liquid receiver 404; the first end of the second solenoid valve 402 is connected to the second opening of the liquid receiver 404, and the second end of the second solenoid valve 402 is connected to the indoor expansion valve in each indoor unit via a pipeline; the first end of the third solenoid valve 403 is connected to the outdoor expansion valve 204 via a pipeline, and the second end of the third solenoid valve 403 is connected to the indoor expansion valve in each indoor unit via a pipeline. Therefore, by controlling the opening or closing of the first solenoid valve 401, the second solenoid valve 402, and the third solenoid valve 403, the flow direction of the refrigerant in the multi-split air conditioning system is controlled.

[0101] In some embodiments, the refrigerant recovery device 400 further includes a fourth solenoid valve 405. The first end of the fourth solenoid valve 405 is connected to the four-way valve 202 via a pipeline, and the second end of the fourth solenoid valve 405 is connected to the indoor heat exchanger in each indoor unit via a pipeline. The fourth solenoid valve 405 is used to control whether refrigerant can flow through the pipeline connecting the four-way valve 202 of the indoor unit 300 and the outdoor unit 200.

[0102] In some embodiments, when the multi-split air conditioning system is in cooling mode, heating mode, first refrigerant recovery mode or second refrigerant recovery mode, the fourth solenoid valve 405 is in the open state.

[0103] Based on this, when the multi-split air conditioning system is running in any of the following modes: cooling mode, heating mode, first refrigerant recovery mode, or second refrigerant recovery mode, the fourth solenoid valve 405 is controlled to be in the open state to ensure that the refrigerant can circulate in the corresponding pipeline.

[0104] In some embodiments, the above-mentioned multi-split air conditioning system has at least one or more of the following operating modes: cooling mode, heating mode, first refrigerant recovery mode, and second refrigerant recovery mode. The above operating modes are described in detail below.

[0105] 1. Cooling Mode

[0106] When the multi-split air conditioning system is in cooling mode, the outdoor heat exchanger 203 works as a condenser, the indoor heat exchanger works as an evaporator, the first solenoid valve 401 is in the closed state, the second solenoid valve 402 is in the closed state, and the third solenoid valve 403 is in the open state.

[0107] In some embodiments, the four-way valve 202 may be a four-way directional valve.

[0108] Taking both indoor unit 300A and indoor unit 300B as examples, which are indoor units requiring cooling, the operating cycle of the air conditioning system's cooling mode is explained in detail. Figure 1 ,like Figure 2 As shown, the D port of the four-way directional valve is connected to the C port, and the E port is connected to the S port; the first solenoid valve 401 and the second solenoid valve 402 are closed, the third solenoid valve 403 and the fourth solenoid valve 405 are open, and the other solenoid valves, indoor expansion valve, outdoor expansion valve, expansion valve and shut-off valve are all open.

[0109] The refrigerant circuit flowing through the first indoor unit 300A in the indoor unit 300 is: (1)→(2)→(3)→(4)→(5)→(6)→(7)→(8)→(9)→(10)→(12)→(14)→(15)→(16)→(17)→(18)→(19)→(1).

[0110] The refrigerant circuit flowing through the second indoor unit 300B in the indoor unit 300 is: (1)→(2)→(3)→(4)→(5)→(6)→(7)→(8)→(9)→(11)→(13)→(14)→(15)→(16)→(17)→(18)→(19)→(1).

[0111] It should be noted that (14)→(15)→(16)→(17) is just an example. The (14)→(15)→(16)→(17) shown in this application can be replaced by one or more pipelines. For example, it can be replaced by pipeline (16), that is, its pipeline only has the fourth solenoid valve 405 or the fourth solenoid valve 405 and the first shut-off valve 407. The number of solenoid valves and shut-off valves installed on this pipeline section is set according to specific requirements.

[0112] Specifically, the high-temperature, high-pressure gaseous refrigerant discharged from compressor 201 enters oil separator 206, where it is divided into two parts. One part enters the inlet of gas-liquid separator 205 through oil return capillary tube 207; the other part, the high-temperature, high-pressure gaseous refrigerant exiting oil separator 206, enters outdoor heat exchanger 203 through one-way valve and four-way valve 202. This high-temperature, high-pressure gaseous refrigerant condenses into medium-temperature, high-pressure liquid refrigerant in outdoor heat exchanger 203. Furthermore, the medium-temperature, high-pressure liquid refrigerant passes sequentially through the outdoor electronic expansion valve and the third solenoid valve 403 of the refrigerant recovery device 400, and is then divided into two parts. One part flows into the first indoor solenoid valve of the first indoor unit 300A to form a low-temperature, low-pressure liquid refrigerant, which then flows into the first indoor heat exchanger 301A and evaporates into a low-temperature, low-pressure gaseous refrigerant. The other part flows into the second indoor solenoid valve of the second indoor unit 300B to form a low-temperature, low-pressure liquid refrigerant, which then flows into the second indoor heat exchanger 301B and evaporates into a low-temperature, low-pressure gaseous refrigerant. The low-temperature, low-pressure gaseous refrigerant, after evaporation in the first indoor heat exchanger 301A and the second indoor heat exchanger 301B, merges and enters the four-way reversing valve through the fourth solenoid valve 405. The low-temperature, low-pressure gaseous refrigerant then enters the gas-liquid separator 205. The low-temperature, low-pressure gaseous refrigerant flowing out of the gas-liquid separator 205 enters the suction port of the compressor 201. The low-temperature, low-pressure gaseous refrigerant is compressed by the compressor 201 into a high-temperature, high-pressure gaseous refrigerant, which is then discharged from the compressor 201. This completes the refrigeration operation of the air conditioning system.

[0113] 2. Heating Mode

[0114] When the multi-split air conditioning system is in heating mode, the outdoor heat exchanger 203 works as an evaporator, the indoor heat exchanger works as a condenser, the first solenoid valve 401 is in the closed state, the second solenoid valve 402 is in the closed state, and the third solenoid valve 403 is in the open state.

[0115] Taking both indoor unit 300A and indoor unit 300B as examples, which are indoor units requiring heating, the operating cycle of the heating mode of the air conditioning system is explained in detail. Figure 1 ,like Figure 3 As shown, the S port of the four-way directional valve is connected to the C port, and the E port is connected to the D port; the first solenoid valve 401 and the second solenoid valve 402 are closed, the third solenoid valve 403 and the fourth solenoid valve 405 are open, and the other solenoid valves, expansion valves and shut-off valves are all open.

[0116] The refrigerant circuit flowing through the first indoor unit 300A in the indoor unit 300 is: (1)→(2)→(18)→(17)→(16)→(15)→(14)→(12)→(10)→(9)→(8)→(7)→(6)→(5)→(4)→(3)→(19)→(1).

[0117] The refrigerant circuit flowing through the second indoor unit 300B in the indoor unit 300 is: (1)→(2)→(18)→(17)→(16)→(15)→(14)→(13)→(11)→(9)→(8)→(7)→(6)→(5)→(4)→(3)→(19)→(1).

[0118] It should be noted that (14)→(15)→(16)→(17) is just an example. The (14)→(15)→(16)→(17) shown in this application can be replaced by one or more pipelines. For example, it can be replaced by pipeline (16), that is, its pipeline only has the fourth solenoid valve 405 or the fourth solenoid valve 405 and the first shut-off valve 407. The number of solenoid valves and shut-off valves installed on this pipeline section is set according to specific requirements.

[0119] Specifically, the high-temperature, high-pressure gaseous refrigerant discharged from compressor 201 enters oil separator 206. The refrigerant entering oil separator 206 is divided into two parts. One part enters the inlet of gas-liquid separator 205 through oil return capillary tube 207; the other part, the high-temperature, high-pressure gaseous refrigerant exiting oil separator 206, is diverted sequentially through a one-way valve, a four-way valve 202, and a fourth solenoid valve 405 into the first indoor heat exchanger 301A of the first indoor unit 300A and the second indoor heat exchanger 301B of the second indoor unit 300B. The first indoor heat exchanger 301A and the second indoor heat exchanger 301B respectively condense the entering high-temperature, high-pressure gaseous refrigerant into medium-temperature, high-pressure liquid refrigerant. The condensed medium-temperature, high-pressure liquid refrigerant then merges after passing through the first indoor expansion valve 302A and the second indoor expansion valve 302B. The merged refrigerant then passes sequentially through the third solenoid valve 403 and the outdoor expansion valve 204, where it is throttled to form a low-temperature, low-pressure liquid refrigerant. The low-temperature, low-pressure liquid refrigerant is evaporated into a low-temperature, low-pressure gaseous refrigerant by the outdoor heat exchanger 203. The low-temperature, low-pressure gaseous refrigerant enters the gas-liquid separator 205. The low-temperature, low-pressure gaseous refrigerant flowing out of the gas-liquid separator 205 enters the suction port of the compressor 201. The low-temperature, low-pressure gaseous refrigerant is compressed into a high-temperature, high-pressure gaseous refrigerant by the compressor 201 and discharged from the compressor 201. This completes the operation of the heating mode of the air conditioning system.

[0120] 3. First refrigerant recovery mode

[0121] When the multi-split air conditioning system is in the first refrigerant recovery mode, the outdoor heat exchanger 203 works as a condenser and the indoor heat exchanger works as an evaporator. The first solenoid valve 401 is in the open state, the second solenoid valve 402 is in the closed state, and the third solenoid valve 403 is in the closed state.

[0122] As one possible implementation, when a refrigerant leak is detected in the indoor unit, regardless of whether the multi-split air conditioning system is in cooling or heating mode, the system is switched to cooling mode while the first solenoid valve 401 is in the open state, the second solenoid valve 402 is in the closed state, and the third solenoid valve 403 is in the closed state.

[0123] Taking the example of refrigerant leakage in the first indoor unit 300A and no refrigerant leakage in the second indoor unit 300B, the operating cycle of the first refrigerant recovery mode of the air conditioning system is explained in detail. Combined with... Figure 2 ,like Figure 4 As shown, the D port of the four-way directional valve is connected to the C port, and the E port is connected to the S port; the first indoor expansion valve 302A is closed, the second solenoid valve 402 is closed, and the third solenoid valve 403 is closed, while the first solenoid valve 401 and the fourth solenoid valve 405 are both open, and the other solenoid valves, other expansion valves, and shut-off valves are all open.

[0124] The refrigerant flow direction through outdoor unit 200 is: (1)→(2)→(3)→(4)→(5)→(6)→(20).

[0125] The refrigerant flow direction through the second indoor unit 300B in the indoor unit 300 is: (8)→(9)→(11)→(13)→(14)→(15)→(16)→(17)→(18)→(19)→(1)→(2)→(3)→(4)→(5)→(6)→(20).

[0126] It should be noted that the refrigerant in pipes (8) and (9) can run to compressor 201 through the second indoor unit 300B (the indoor unit where no refrigerant leakage has occurred), and be discharged by compressor 201 or recovered to refrigerant recovery device 400.

[0127] Specifically, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 201 enters the oil separator 206, where it is divided into two parts. One part enters the inlet of the gas-liquid separator 205 through the oil return capillary tube 207; the other part, the high-temperature, high-pressure gaseous refrigerant exiting the oil separator 206, passes through a one-way valve and a four-way valve 202 before entering the outdoor heat exchanger 203. This high-temperature, high-pressure gaseous refrigerant condenses into a medium-temperature, high-pressure liquid refrigerant in the outdoor heat exchanger 203. Further, this medium-temperature, high-pressure liquid refrigerant passes sequentially through the outdoor electronic expansion valve and the first solenoid valve 401 of the refrigerant recovery device 400, and is then stored in the liquid storage tank 404. Low-temperature, low-pressure liquid refrigerant in pipes (8) and (9) flows into the second indoor solenoid valve of the second indoor unit 300B to form low-temperature, low-pressure liquid refrigerant. The low-temperature, low-pressure liquid refrigerant then flows into the second indoor heat exchanger 301B, where it evaporates into low-temperature, low-pressure gaseous refrigerant. This low-temperature, low-pressure gaseous refrigerant passes through the fourth solenoid valve 405 and enters the four-way reversing valve, where it enters the gas-liquid separator 205. The low-temperature, low-pressure gaseous refrigerant flowing out of the gas-liquid separator 205 enters the suction port of the compressor 201, where it is compressed by the compressor 201 into high-temperature, high-pressure gaseous refrigerant, which is then discharged from the compressor 201. This completes the operation of the first refrigerant recovery mode of the air conditioning system.

[0128] Optionally, during the first refrigerant recovery mode operation, the indoor expansion valve corresponding to the indoor unit where refrigerant leakage occurs is closed, while the indoor expansion valve corresponding to the indoor unit where no refrigerant leakage occurs is opened to the maximum degree.

[0129] For example, when the refrigerant leaks in the first indoor unit 300A and the refrigerant does not leak in the second indoor unit 300B, the first indoor expansion valve 302A closes while the second indoor expansion valve 302B opens to its maximum value.

[0130] 4. Second refrigerant recovery mode

[0131] When the multi-split air conditioning system is in the second refrigerant recovery mode, the outdoor heat exchanger 203 works as an evaporator, the indoor heat exchanger works as a condenser, the first solenoid valve 401 is in the closed state, the second solenoid valve 402 is in the open state, and the third solenoid valve 403 is in the closed state.

[0132] Taking the outdoor unit 200 leak as an example, as a possible implementation, when a refrigerant leak is detected in the outdoor unit 200, regardless of whether the multi-split air conditioning system is in cooling mode or heating mode, while controlling the first solenoid valve 401 to be closed, the second solenoid valve 402 to be open, and the third solenoid valve 403 to be closed, the multi-split air conditioning system is switched to heating mode.

[0133] The operating cycle of the second refrigerant recovery mode of the air conditioning system is explained in detail. (Combined with...) Figure 3 ,like Figure 5 As shown, the S port of the four-way directional valve is connected to the C port, and the E port is connected to the D port; the first solenoid valve 401 and the third solenoid valve 403 are closed, the second solenoid valve 402 and the fourth solenoid valve 405 are open, and the other solenoid valves, expansion valves and shut-off valves are all open.

[0134] The refrigerant flow direction of the first indoor unit 300A in the indoor unit 300 is: (1)→(2)→(18)→(17)→(16)→(15)→(14)→(12)→(10)→(9)→(21).

[0135] The refrigerant flow direction through the second indoor unit 300B in the indoor unit 300 is: (1)→(2)→(18)→(17)→(16)→(15)→(14)→(13)→(11)→(9)→(21).

[0136] The refrigerant flow direction of outdoor unit 200 is: (3) → (19) → (1).

[0137] Specifically, the high-temperature, high-pressure gaseous refrigerant discharged from compressor 201 enters oil separator 206. The refrigerant entering oil separator 206 is divided into two parts. One part enters the inlet of gas-liquid separator 205 through oil return capillary tube 207; the other part, the high-temperature, high-pressure gaseous refrigerant exiting oil separator 206, is diverted sequentially through a one-way valve, a four-way valve 202, and a fourth solenoid valve 405 into the first indoor heat exchanger 301A of the first indoor unit 300A and the second indoor heat exchanger 301B of the second indoor unit 300B. The first indoor heat exchanger 301A and the second indoor heat exchanger 301B respectively condense the entering high-temperature, high-pressure gaseous refrigerant into medium-temperature, high-pressure liquid refrigerant. The condensed medium-temperature, high-pressure liquid refrigerant then merges after passing through the first indoor expansion valve 302A and the second indoor expansion valve 302B respectively. The merged refrigerant is then stored in liquid storage tank 404 through the second solenoid valve 402. The refrigerant in the outdoor unit 200 evaporates into a low-temperature, low-pressure gaseous refrigerant through the outdoor heat exchanger 203. This low-temperature, low-pressure gaseous refrigerant enters the gas-liquid separator 205. The low-temperature, low-pressure gaseous refrigerant flowing out of the gas-liquid separator 205 enters the suction port of the compressor 201. The low-temperature, low-pressure gaseous refrigerant is compressed into a high-temperature, high-pressure gaseous refrigerant by the compressor 201 and discharged from the compressor 201. This completes the operation of the second refrigerant recovery mode of the air conditioning system.

[0138] Based on the four different operating modes mentioned above, the multi-split air conditioning system can provide a corresponding operating mode for different scenarios. Specifically, when cooling is required (e.g., when the room temperature is too high), the operating mode of the multi-split air conditioning system is switched to cooling mode to lower the indoor ambient temperature. When heating is required (e.g., when the room temperature is too low), the operating mode of the multi-split air conditioning system is switched to heating mode to raise the indoor ambient temperature. When it is necessary to recover refrigerant leaked from the indoor unit, the multi-split air conditioning system can be switched to the first refrigerant recovery mode, and the refrigerant recovery device 400 can recover the leaked refrigerant from the indoor unit. When it is necessary to recover refrigerant leaked from the outdoor unit 200, the multi-split air conditioning system can be switched to the second refrigerant recovery mode, and the refrigerant recovery device 400 can recover the leaked refrigerant from the outdoor unit 200.

[0139] In some embodiments, the multi-split air conditioning system 100 further includes a controller ( Figure 1 (Not shown in the image).

[0140] In some embodiments, a controller refers to a device that can generate operation control signals based on instruction opcodes and timing signals, instructing a multi-split air conditioning system to execute control instructions. Exemplarily, the controller can be a central processing unit (CPU), a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. The controller can also be other devices with processing capabilities, such as circuits, devices, or software modules; this application does not impose any limitations on these aspects.

[0141] although Figure 1 As not shown, a multi-split air conditioning system may also include a power supply device (such as a battery and a power management chip) to supply power to various components. The battery can be logically connected to the controller through the power management chip, thereby enabling the power consumption management and other functions of the multi-split air conditioning system through the power supply device.

[0142] In some embodiments, the controller is electrically connected to an indoor refrigerant leak detection device in each indoor unit; the controller is configured to: acquire the detection result of each indoor refrigerant leak detection device, the detection result of one indoor refrigerant leak detection device being used to indicate whether a refrigerant leak has occurred in the indoor unit where the refrigerant leak detection device is located; determine, based on the detection result of each indoor refrigerant leak detection device, whether there is an indoor unit in the indoor unit group 300 that has experienced a refrigerant leak; if so, control the multi-split air conditioning system to operate in a first refrigerant recovery mode.

[0143] In this way, the multi-split air conditioning system can identify the indoor unit 300 experiencing a refrigerant leak based on the detection results of the indoor refrigerant leak detection device. If a refrigerant leak occurs in an indoor unit 300, the multi-split air conditioning system switches to the first refrigerant recovery mode, recovering the leaked refrigerant from the indoor unit to the refrigerant recovery device 400. This prevents refrigerant leaks from the indoor unit into the indoor environment, thus improving the safety of the multi-split air conditioning system. Furthermore, by recovering the refrigerant through the refrigerant recovery device 400, the amount of refrigerant emitted from the outdoor unit 200 into the outdoor environment is significantly reduced, improving the environmental friendliness of the multi-split air conditioning system.

[0144] In some embodiments, the controller is further configured to: close the indoor expansion valve in the indoor unit where a refrigerant leak has occurred when the multi-split air conditioning system is operating in a first refrigerant recovery mode.

[0145] In this embodiment, when the multi-split air conditioning system is operating in the first refrigerant recovery mode, the indoor expansion valve in the indoor unit where refrigerant leakage has occurred is closed to prevent refrigerant from continuing to enter the indoor unit where refrigerant leakage has occurred, thereby preventing refrigerant from leaking from the indoor unit into the indoor environment and ensuring the safe use of the multi-split air conditioning system by the user.

[0146] Optionally, when the multi-split air conditioning system is operating in the first refrigerant recovery mode, the opening degree of the indoor expansion valve of the indoor unit 300 that has not experienced refrigerant leakage is adjusted to the maximum opening degree. This allows the refrigerant in the pipe connected to the indoor expansion valve of the indoor unit that has experienced refrigerant leakage to be recovered more quickly through the indoor unit and outdoor unit 200 to the refrigerant recovery device 400, thereby improving the recovery speed of the leaked refrigerant from the indoor unit and ensuring the refrigerant recovery efficiency of the multi-split air conditioning system.

[0147] In some embodiments, the controller is further configured to: in the first refrigerant recovery mode, when the refrigerant recovery stop condition is met, control the fourth solenoid valve 405 to close; wherein the refrigerant recovery stop condition includes one or more of the following: the duration of the multi-split air conditioning system operating in the first refrigerant recovery mode reaches a preset duration; or, the pressure of the refrigerant entering the compressor 201 is within a preset pressure range.

[0148] It should be noted that the above-mentioned preset pressure range is determined based on the atmospheric pressure of the outdoor environment.

[0149] Optionally, the refrigerant pressure of the compressor 201 is set by means of... Figure 2 The pressure is detected by the first outdoor pressure sensor 209 located at the air inlet of the compressor 201.

[0150] Based on this, by setting refrigerant recovery stop conditions, the timing for ending refrigerant recovery can be determined so that refrigerant is recovered when the amount of refrigerant in the piping of the multi-split air conditioning system is within a reasonable range. This avoids the multi-split air conditioning system from still executing the first refrigerant recovery mode when there is no refrigerant in the piping, which could cause abnormalities or damage to the multi-split air conditioning system, thereby improving the safety and service life of the multi-split air conditioning system.

[0151] Based on the above embodiments, the refrigerant recovery device 400 is also provided with a fifth solenoid valve 406. The first end of the fifth solenoid valve 406 is connected to the second end of the fourth solenoid valve 405 through a pipeline, and the second end of the fifth solenoid valve 406 is connected to the indoor heat exchanger in each indoor unit through a pipeline. When the multi-split air conditioning system is in cooling mode, heating mode, or the first refrigerant recovery mode, the fifth solenoid valve 406 is in the open state.

[0152] Based on the above embodiments, the controller is further configured to: in the first refrigerant recovery mode, when the refrigerant recovery stop condition is met, control the fifth solenoid valve 406 to close; wherein, the refrigerant recovery stop condition includes one or more of the following: the duration of the multi-split air conditioning system running the first refrigerant recovery mode has reached a preset duration; or, the pressure of the refrigerant entering the compressor 201 is within a preset pressure range.

[0153] In some embodiments, the outdoor unit 200 controller is electrically connected to the outdoor refrigerant leak detection device of the outdoor unit 200; the controller is configured to: acquire the detection result of the outdoor refrigerant leak detection device, the detection result of the outdoor refrigerant leak detection device being used to indicate whether the outdoor unit 200 has experienced a refrigerant leak; if the detection result of the outdoor refrigerant leak detection device indicates that the outdoor unit 200 has experienced a refrigerant leak, control the multi-split air conditioning system to operate in a second refrigerant recovery mode.

[0154] In this way, the multi-split air conditioning system can determine whether outdoor unit 200 has experienced a refrigerant leak based on the detection results of the outdoor refrigerant leak detection device. If a refrigerant leak occurs in outdoor unit 200, the system switches to a second refrigerant recovery mode to recover the leaked refrigerant into the refrigerant recovery device 400. This significantly reduces the amount of refrigerant emitted from outdoor unit 200 into the outdoor environment, improving the environmental friendliness of the multi-split air conditioning system.

[0155] In some embodiments, when the multi-split air conditioning system is operating in the second refrigerant recovery mode, the outdoor expansion valve 204 is controlled to be at its maximum opening value.

[0156] In this embodiment, when the multi-split air conditioning system is running in the second refrigerant recovery mode, the outdoor expansion valve 204 is controlled to be at its maximum opening value so that the refrigerant in the pipeline connected to the outdoor expansion valve 204 can be recovered to the refrigerant recovery device 400 more quickly through the outdoor unit 200 and the indoor unit, thereby improving the recovery speed of the refrigerant leaking from the outdoor unit 200 and ensuring the refrigerant recovery efficiency of the multi-split air conditioning system.

[0157] In some embodiments, the controller is further configured to: in the second refrigerant recovery mode, when the refrigerant recovery stop condition is met, control the fourth solenoid valve 405 to close; wherein the refrigerant recovery stop condition includes one or more of the following: the duration of the multi-split air conditioning system operating in the second refrigerant recovery mode reaches a preset duration; or, the pressure of the refrigerant entering the compressor 201 is within a preset pressure range.

[0158] It should be noted that the above-mentioned preset pressure range is determined based on the atmospheric pressure of the outdoor environment.

[0159] Optionally, the refrigerant pressure of the compressor 201 is set by means of... Figure 2 The pressure is detected by the first outdoor pressure sensor 209 located at the air inlet of the compressor 201.

[0160] Based on this, by setting refrigerant recovery stop conditions, the timing for ending refrigerant recovery can be determined so that refrigerant is recovered when the amount of refrigerant in the piping of the multi-split air conditioning system is within a reasonable range. This avoids the multi-split air conditioning system from still executing the second refrigerant recovery mode when there is no refrigerant in the piping, which could cause abnormalities or damage to the multi-split air conditioning system, thereby improving the safety and service life of the multi-split air conditioning system.

[0161] Based on the above embodiments, and in conjunction with the above... Figure 4 like Figure 6 and Figure 7 As shown, the refrigerant recovery device 400 is also equipped with an expansion valve 411.

[0162] The expansion valve 411 can be configured in the following two ways: (1) The first end of the expansion valve 411 is connected to the second end of the fourth solenoid valve 405 through a pipeline, and the second end of the expansion valve 411 is connected to the second end of the first solenoid valve 401 through a pipeline. (2) The first end of the expansion valve 411 is connected to the second end of the fourth solenoid valve 405 through a pipeline, and the second end of the expansion valve 411 is connected to the third opening of the liquid storage tank 404 through a pipeline.

[0163] It should be noted that the above-mentioned expansion valve 411 setting method (1) applies to the first refrigerant recovery mode. The above-mentioned expansion valve 411 setting method (2) applies to both the first and second refrigerant recovery modes. Of course, the two methods can also be used in combination, depending on the specific circumstances. This application does not impose specific limitations on the setting method of expansion valve 411.

[0164] In this embodiment, during the refrigerant recovery process, as the amount of refrigerant circulating within the multi-split air conditioning system decreases and the low pressure of the system approaches the preset pressure range (typically referring to the atmospheric pressure of the environment where the system is located), the discharge temperature of compressor 201 will increase, potentially affecting its reliability. Therefore, an expansion valve 411 is added between the first solenoid valve 401 and the fourth solenoid valve 405, or between the fourth solenoid valve 405 and the liquid receiver 404. During refrigerant recovery, this expansion valve 411 is opened, allowing a portion of the refrigerant to bypass the compressor 201, thereby reducing its discharge temperature and ensuring its reliability during refrigerant recovery.

[0165] Furthermore, during the refrigerant recovery process, the refrigerant entering the receiver 404 may be a two-phase refrigerant consisting of gaseous and liquid components. When the refrigerant entering the receiver 404 is a two-phase refrigerant, the average density of the two-phase refrigerant is lower, resulting in a reduced amount of refrigerant stored in the receiver 404, thus affecting the refrigerant recovery efficiency. Therefore, during the refrigerant recovery process, the expansion valve 411 is opened to allow gaseous refrigerant to bypass the refrigerant and improve the refrigerant recovery efficiency.

[0166] Based on the above embodiments, the refrigerant recovery device 400 is also provided with a fifth solenoid valve 406. The first end of the fifth solenoid valve 406 is connected to the second end of the fourth solenoid valve 405 through a pipeline, and the second end of the fifth solenoid valve 406 is connected to the indoor heat exchanger in each indoor unit through a pipeline. When the multi-split air conditioning system is in cooling mode, heating mode, or second refrigerant recovery mode, the fifth solenoid valve 406 is in the open state.

[0167] Based on the above embodiments, the controller is further configured to: in the second refrigerant recovery mode, when the refrigerant recovery stop condition is met, control the fifth solenoid valve 406 to close; wherein, the refrigerant recovery stop condition includes one or more of the following: the duration of the multi-split air conditioning system running the second refrigerant recovery mode has reached a preset duration; or, the pressure of the refrigerant entering the compressor 201 is within a preset pressure range.

[0168] In this embodiment, the indoor expansion valve corresponding to the indoor unit in the indoor unit 300 where refrigerant leakage occurs is in a closed state. After refrigerant recovery is completed, the fourth solenoid valve 405 and the fifth solenoid valve 406 are closed by controlling them, so that the indoor units in the indoor unit 300 where refrigerant leakage occurs are freely separated from the refrigerant recovery device 400 and the outdoor unit 200. This allows the replacement of the indoor unit with refrigerant leakage to be unaffected by the refrigerant recovery device 400 and the outdoor unit 200, improving the convenience of installing or replacing the indoor unit.

[0169] For example, an indoor expansion valve includes, Figure 2 The first indoor expansion valve 302A and the second indoor expansion valve 302B are shown.

[0170] Based on the above embodiments, the outdoor unit 200 is also equipped with a sixth solenoid valve 213 and a seventh solenoid valve 214.

[0171] The sixth solenoid valve 213 is installed on the pipeline between the four-way valve 202 and the fifth shut-off valve 211. The first end of the sixth solenoid valve 213 is connected to the four-way valve 202 through a pipeline, and the second end of the sixth solenoid valve 213 is connected to the first end of the fifth shut-off valve 211 through a pipeline. The seventh solenoid valve 214 is installed on the pipeline between the outdoor expansion valve 204 and the sixth shut-off valve 212. The first end of the seventh solenoid valve 214 is connected to the outdoor expansion valve 204 through a pipeline, and the second end of the seventh solenoid valve 214 is connected to the first end of the sixth shut-off valve 212 through a pipeline.

[0172] Based on the aforementioned sixth solenoid valve 213 and seventh solenoid valve 214, after refrigerant recovery is completed, by controlling the sixth solenoid valve 213 and the seventh solenoid valve 214 to close, the outdoor unit 200 is freely separated from the refrigerant recovery device 400 and the indoor unit 300, so that the outdoor unit 200 is not affected by the refrigerant recovery device 400 and the indoor unit 300 during the replacement process, thereby improving the convenience of installing or replacing the outdoor unit 200.

[0173] Based on the above embodiments, the refrigerant recovery device 400 further includes: a first shut-off valve 407, which is disposed on the pipeline between the four-way valve 202 and the fourth solenoid valve 405, with a first end connected to the four-way valve 202 via a pipeline and a second end connected to the first end of the fourth solenoid valve 405 via a pipeline; and a second shut-off valve 408, which is disposed on the pipeline between the fourth solenoid valve 405 and the indoor heat exchanger, with a first end connected to the second end of the fourth solenoid valve 405 via a pipeline and a second end connected to the indoor heat exchanger in each indoor unit. The heat exchanger is connected via pipes; a third shut-off valve 409 is installed on the pipe between the outdoor expansion valve 204 and the first solenoid valve 401, with the first end of the third shut-off valve 409 connected to the outdoor expansion valve 204 via a pipe and the second end of the third shut-off valve 409 connected to the first end of the first solenoid valve 401 via a pipe; a fourth shut-off valve 410 is installed on the pipe between the second solenoid valve 402 and the indoor heat exchanger, with the first end of the fourth shut-off valve 410 connected to the second end of the second solenoid valve 402 via a pipe and the second end of the fourth shut-off valve 410 connected to the indoor expansion valve in each indoor unit via a pipe.

[0174] In this embodiment, during the operation of the multi-split air conditioning system in either the first or second refrigerant recovery mode, the first shut-off valve 407, the second shut-off valve 408, the third shut-off valve 409, and the fourth shut-off valve 410 are in the open state. After the first or second refrigerant recovery mode operation is completed, the first solenoid valve 401, the second solenoid valve 402, and the third solenoid valve 403 are in the closed state, while the first shut-off valve 407, the second shut-off valve 408, the third shut-off valve 409, and the fourth shut-off valve 410 are in the closed state to better prevent the flow of refrigerant in the corresponding pipelines of the shut-off valves.

[0175] In some embodiments, the outdoor unit 200 further includes: a fifth shut-off valve 211, which is disposed on the pipeline between the four-way valve 202 and the first shut-off valve 407, wherein the first end of the fifth shut-off valve 211 is connected to the four-way valve 202 through a pipeline, and the second end of the fifth shut-off valve 211 is connected to the first end of the first shut-off valve 407 through a pipeline; and a sixth shut-off valve 212, which is disposed on the pipeline between the outdoor expansion valve 204 and the third shut-off valve 409, wherein the first end of the sixth shut-off valve 212 is connected to the outdoor expansion valve 204 through a pipeline, and the second end of the sixth shut-off valve 212 is connected to the first end of the third shut-off valve 409 through a pipeline.

[0176] It should be noted that the number of shut-off valves in a multi-split air conditioning system can be adjusted according to specific requirements. For example, two shut-off valves can be installed at each end of the indoor unit 300, with one shut-off valve located at the end of the indoor unit 300 connected to the four-way valve 202. Figures 2 to 7 On the pipe (14) shown, another shut-off valve is installed at one end of the indoor unit 300 and the refrigerant recovery device 400, i.e. Figures 2 to 7 On the pipeline (9) shown.

[0177] In this embodiment, during the operation of the multi-split air conditioning system in either the first or second refrigerant recovery mode, the fifth shut-off valve 211 and the sixth shut-off valve 212 are in the open state. After the first or second refrigerant recovery mode is completed, the fifth solenoid valve 406 and the sixth solenoid valve 213 are in the closed state to better prevent the flow of refrigerant in the pipelines corresponding to the shut-off valves.

[0178] like Figure 8 The control flowchart of the multi-split air conditioning system is shown.

[0179] S801 detects refrigerant leaks in the indoor and outdoor units.

[0180] S802, when an indoor unit with refrigerant leakage is detected, controls the multi-split air conditioning system to operate in the first refrigerant recovery mode.

[0181] S803, when a refrigerant leak is detected in the outdoor unit, controls the multi-split air conditioning system to operate in the second refrigerant recovery mode.

[0182] S804 maintains its original operating mode if no refrigerant leaks are detected in the indoor and outdoor units.

[0183] It should be noted that the original operating mode could be cooling mode, heating mode, dehumidification mode, or other modes that the air conditioning system operates in.

[0184] In the first refrigerant recovery mode, the outdoor heat exchanger functions as a condenser, the indoor heat exchanger functions as an evaporator, and the first solenoid valve is open, the second solenoid valve is closed, and the third solenoid valve is closed. In the second refrigerant recovery mode, the outdoor heat exchanger functions as an evaporator, the indoor heat exchanger functions as a condenser, and the first solenoid valve is closed, the second solenoid valve is open, and the third solenoid valve is closed.

[0185] like Figure 9 The multi-split air conditioning system shown is in the control process of the first refrigerant recovery mode.

[0186] (1) An indoor unit with a refrigerant leak is detected. The presence of such a leaking indoor unit will typically trigger a warning message. This warning message indicates that a refrigerant leak has occurred. The warning message can be delivered via voice, text, or light.

[0187] (2) Determine whether the multi-split air conditioning system is in cooling mode.

[0188] (3) If not, after switching the multi-split air conditioning system to cooling mode, control the indoor expansion valve corresponding to the indoor unit where the refrigerant leak occurred to be closed, the first solenoid valve to be open, the second solenoid valve to be closed and the third solenoid valve to be closed.

[0189] (4) If so, control the first solenoid valve to be in the open state, control the indoor expansion valve corresponding to the indoor unit where the refrigerant leak occurs to be in the closed state, control the first solenoid valve to be in the open state, control the second solenoid valve to be in the closed state and control the third solenoid valve to be in the closed state.

[0190] (5) When the multi-split air conditioning system operates in the first refrigerant recovery mode for a preset duration; or when the pressure of the refrigerant entering the compressor is within a preset pressure range, the fourth solenoid valve is closed, and a first replacement message is issued. This first replacement message is used to prompt the user to replace the indoor unit where a refrigerant leak has occurred.

[0191] (6) Control the multi-split air conditioning system to stop operating.

[0192] like Figure 10 The multi-split air conditioning system shown is in the control process of the second refrigerant recovery mode.

[0193] (1) A refrigerant leak is detected in the outdoor unit. The outdoor unit will usually issue a warning message. The warning message indicates that a refrigerant leak has occurred in the outdoor unit. The warning message can be given in the form of voice, text, or light.

[0194] (2) Determine whether the multi-split air conditioning system is in heating mode.

[0195] (3) If not, switch the multi-split air conditioning system to heating mode, then control the first solenoid valve to be closed, the second solenoid valve to be open, and the third solenoid valve to be closed.

[0196] (4) If so, control the first solenoid valve to be closed, the second solenoid valve to be open, and the third solenoid valve to be closed.

[0197] (5) When the duration of the second refrigerant recovery mode in the multi-split air conditioning system reaches the preset duration; or when the pressure of the refrigerant entering the compressor is within the preset pressure range, the fourth solenoid valve is closed, and a second replacement message is issued. This second replacement message is used to prompt the user to replace the outdoor unit.

[0198] (6) Control the multi-split air conditioning system to stop operating.

[0199] Furthermore, embodiments of this application provide corresponding hardware structures and / or software modules for performing various functions. Those skilled in the art will readily recognize that, in conjunction with the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, embodiments of this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is implemented in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention.

[0200] This application embodiment can divide the controller into functional modules according to the above method example. For example, each function can be divided into a separate functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. Optionally, the module division in this application embodiment is illustrative and only represents one logical functional division; other division methods may be used in actual implementation.

[0201] This application also provides a hardware structure diagram of a controller, such as... Figure 11 As shown, the controller 2000 includes a processor 2001, and optionally, a memory 2002 and a communication interface 2003 connected to the processor 2001. The processor 2001, memory 2002, and communication interface 2003 are connected via a bus 2004.

[0202] Processor 2001 may be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. Processor 2001 may also be any other device with processing capabilities, such as a circuit, device, or software module. Processor 2001 may also include multiple CPUs, and processor 2001 may be a single-core processor or a multi-core processor. Here, "processor" may refer to one or more devices, circuits, or processing cores used to process data (e.g., computer program instructions).

[0203] The memory 2002 can be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions. It can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), a magnetic disk storage medium, or other magnetic storage device, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer. This application embodiment does not impose any limitations on this. The memory 2002 can exist independently or be integrated with the processor 2001. The memory 2002 may contain computer program code. The processor 2001 executes the computer program code stored in the memory 2002 to implement the control method provided in this application embodiment.

[0204] The communication interface 2003 can be used to communicate with other devices or communication networks (such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.). The communication interface 2003 can be a module, circuit, transceiver, or any device capable of enabling communication.

[0205] Bus 2004 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. Bus 2004 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 11 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0206] This invention also provides a computer-readable storage medium including computer-executable instructions that, when executed on a computer, cause the computer to perform the method provided in the above embodiments.

[0207] This invention also provides a computer program product that can be directly loaded into a memory and contains software code. After being loaded and executed by a computer, the computer program product can implement the methods provided in the above embodiments.

[0208] Those skilled in the art will recognize that, in one or more of the examples above, the functions described in this invention can be implemented using hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transfer of a computer program from one place to another. Storage media can be any available medium accessible to a general-purpose or special-purpose computer.

[0209] Through the above description of the embodiments, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0210] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and other division methods may exist in actual implementation. For example, multiple modules or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between devices or modules may be electrical, mechanical, or other forms. Modules described as separate components may or may not be physically separate; components shown as modules may be one physical module or multiple physical modules, i.e., they may be located in one place or distributed in multiple different places. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0211] Furthermore, the functional units in the various embodiments of this invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiments of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0212] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A multi-split air conditioning system, characterized in that, include: The outdoor unit includes a compressor, a four-way valve, an outdoor heat exchanger, and an outdoor expansion valve connected in sequence. An indoor unit, comprising multiple indoor units connected in parallel, each indoor unit including an indoor heat exchanger and an indoor expansion valve; A refrigerant recovery device includes: a first solenoid valve, a second solenoid valve, a third solenoid valve, and a liquid storage tank; wherein, a first end of the first solenoid valve is connected to the outdoor expansion valve via a pipeline, and a second end of the first solenoid valve is connected to a first opening of the liquid storage tank; a first end of the second solenoid valve is connected to a second opening of the liquid storage tank, and a second end of the second solenoid valve is connected to an indoor expansion valve in each of the indoor units via a pipeline; a first end of the third solenoid valve is connected to the outdoor expansion valve via a pipeline, and a second end of the third solenoid valve is connected to an indoor expansion valve in each of the indoor units via a pipeline; The multi-split air conditioning system has multiple operating modes, including a cooling mode, a heating mode, a first refrigerant recovery mode, and a second refrigerant recovery mode. When the multi-split air conditioning system is in cooling mode, the outdoor heat exchanger works as a condenser, the indoor heat exchanger works as an evaporator, the first solenoid valve is in the closed state, the second solenoid valve is in the closed state, and the third solenoid valve is in the open state. When the multi-split air conditioning system is in heating mode, the outdoor heat exchanger works as an evaporator, the indoor heat exchanger works as a condenser, the first solenoid valve is in the closed state, the second solenoid valve is in the closed state, and the third solenoid valve is in the open state. When the multi-split air conditioning system is in the first refrigerant recovery mode, the outdoor heat exchanger works as a condenser, the indoor heat exchanger works as an evaporator, the first solenoid valve is in the open state, the second solenoid valve is in the closed state, and the third solenoid valve is in the closed state. When the multi-split air conditioning system is in the second refrigerant recovery mode, the outdoor heat exchanger works as an evaporator, the indoor heat exchanger works as a condenser, the first solenoid valve is in the closed state, the second solenoid valve is in the open state, and the third solenoid valve is in the closed state.

2. The multi-split air conditioning system according to claim 1, characterized in that, Each of the indoor units also includes an indoor refrigerant leak detection device; The multi-split air conditioning system also includes: The controller is electrically connected to the indoor refrigerant leak detection device in each of the indoor units; the controller is configured to: Obtain the detection result of each of the indoor refrigerant leak detection devices. The detection result of one of the indoor refrigerant leak detection devices is used to indicate whether the indoor unit where the refrigerant leak detection device is located has experienced a refrigerant leak. Based on the detection results of each of the indoor refrigerant leak detection devices, determine whether there is an indoor unit in the indoor unit that has experienced a refrigerant leak; If present, control the multi-split air conditioning system to operate in the first refrigerant recovery mode.

3. The multi-split air conditioning system according to claim 2, characterized in that, The outdoor unit also includes an outdoor refrigerant leak detection device; The controller is electrically connected to the outdoor refrigerant leak detection device of the outdoor unit; The controller is configured to: The detection results of the outdoor refrigerant leak detection device are obtained, and the detection results of the outdoor refrigerant leak detection device are used to indicate whether the outdoor unit has experienced a refrigerant leak. If the detection result of the outdoor refrigerant leak detection device indicates that the outdoor unit has a refrigerant leak, the system is controlled to operate in the second refrigerant recovery mode.

4. The multi-split air conditioning system according to claim 3, characterized in that, The controller is also configured to: When the multi-split air conditioning system is operating in the first refrigerant recovery mode, the indoor expansion valve in the indoor unit where refrigerant leakage has occurred is closed. When the multi-split air conditioning system is operating in the second refrigerant recovery mode, the outdoor expansion valve is controlled to be at its maximum opening value.

5. The multi-split air conditioning system according to claim 4, characterized in that, The refrigerant recovery device also includes a fourth solenoid valve, the first end of which is connected to the four-way valve via a pipeline, and the second end of which is connected to the indoor heat exchanger in each of the indoor units via a pipeline. When the multi-split air conditioning system is in cooling mode, heating mode, first refrigerant recovery mode or second refrigerant recovery mode, the fourth solenoid valve is in the open state.

6. The multi-split air conditioning system according to claim 5, characterized in that, The controller is also configured to: In the first refrigerant recovery mode and the second refrigerant recovery mode, when the refrigerant recovery stop condition is met, the fourth solenoid valve is controlled to close. The refrigerant recovery shutdown conditions include one or more of the following: The multi-split air conditioning system operates in either the first refrigerant recovery mode or the second refrigerant recovery mode for a preset duration; or... The pressure of the refrigerant entering the compressor is within the preset pressure range.

7. The multi-split air conditioning system according to claim 5, characterized in that, The refrigerant recovery device also includes a fifth solenoid valve, the first end of which is connected to the second end of the fourth solenoid valve via a pipeline, and the second end of which is connected to the indoor heat exchanger in each of the indoor units via a pipeline. When the multi-split air conditioning system is in cooling mode, heating mode, first refrigerant recovery mode, or second refrigerant recovery mode, the fifth solenoid valve is in the open state.

8. The multi-split air conditioning system according to claim 7, characterized in that, The controller is also configured to: In either the first or second refrigerant recovery mode, the fifth solenoid valve is controlled to close when the refrigerant recovery stop condition is met. The refrigerant recovery shutdown conditions include one or more of the following: The multi-split air conditioning system has been operating in either the first or second refrigerant recovery mode for a preset duration; or, The pressure of the refrigerant entering the compressor is within the preset pressure range.

9. The multi-split air conditioning system according to claim 7, characterized in that, The refrigerant recovery device also includes an expansion valve; Wherein, the first end of the expansion valve is connected to the second end of the fourth solenoid valve through a pipeline, and the second end of the expansion valve is connected to the second end of the first solenoid valve through a pipeline; or, The first end of the expansion valve is connected to the second end of the fourth solenoid valve through a pipeline, and the second end of the expansion valve is connected to the third opening of the storage tank through a pipeline.

10. The multi-split air conditioning system according to claim 5, characterized in that, The refrigerant recovery device also includes: A first shut-off valve is disposed on the pipeline between the four-way valve and the fourth solenoid valve. The first end of the first shut-off valve is connected to the four-way valve through a pipeline, and the second end of the first shut-off valve is connected to the first end of the fourth solenoid valve through a pipeline. The second shut-off valve is installed on the pipeline between the fourth solenoid valve and the indoor heat exchanger. The first end of the second shut-off valve is connected to the second end of the fourth solenoid valve through a pipeline, and the second end of the second shut-off valve is connected to the indoor heat exchanger in each of the indoor units through a pipeline. The third shut-off valve is disposed on the pipeline between the outdoor expansion valve and the first solenoid valve. The first end of the third shut-off valve is connected to the outdoor expansion valve through a pipeline, and the second end of the third shut-off valve is connected to the first end of the first solenoid valve through a pipeline. The fourth shut-off valve is installed on the pipeline between the second solenoid valve and the indoor heat exchanger. The first end of the fourth shut-off valve is connected to the second end of the second solenoid valve through a pipeline, and the second end of the fourth shut-off valve is connected to the indoor expansion valve in each of the indoor units through a pipeline.

11. The multi-split air conditioning system according to claim 10, characterized in that, The outdoor unit also includes: The fifth shut-off valve is disposed on the pipeline between the four-way valve and the first shut-off valve. The first end of the fifth shut-off valve is connected to the four-way valve through a pipeline, and the second end of the fifth shut-off valve is connected to the first end of the first shut-off valve through a pipeline. A sixth shut-off valve is provided on the pipeline between the outdoor expansion valve and the third shut-off valve. The first end of the sixth shut-off valve is connected to the outdoor expansion valve through a pipeline, and the second end of the sixth shut-off valve is connected to the first end of the third shut-off valve through a pipeline.

12. The multi-split air conditioning system according to claim 11, characterized in that, The outdoor unit also includes: The sixth solenoid valve is disposed on the pipeline between the four-way valve and the fifth shut-off valve. The first end of the sixth solenoid valve is connected to the four-way valve through a pipeline, and the second end of the sixth solenoid valve is connected to the first end of the fifth shut-off valve through a pipeline. A seventh solenoid valve is disposed on the pipeline between the outdoor expansion valve and the sixth shut-off valve. The first end of the seventh solenoid valve is connected to the outdoor expansion valve through a pipeline, and the second end of the seventh solenoid valve is connected to the first end of the sixth shut-off valve through a pipeline.

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