Air conditioning system

Abstract

An air conditioning system (1) comprises a first throttling device (217), a second throttling device (218), a third pipeline (350), a fourth pipeline (360) and a control part (13). The control part (13) is configured to control the air conditioning system (1) to execute a refrigerant recovery mode when leakage of the refrigerant occurs. The control part (13) is further configured to correct the opening degree of the first throttling device (217) based on the difference value between the temperature of the refrigerant in the third pipeline (350) and the temperature of the refrigerant in the fourth pipeline (360) when the air conditioning system (1) executes the refrigerant recovery mode; correcting the opening degree of the second throttle device (218) on the basis of the difference between the temperatures of the refrigerant in the fourth line (360) and the third line (350); and controlling the opening change of the first throttling device (217) and the second throttling device (218) in the refrigerant recovery mode not to exceed a preset range.

Description

Air conditioning system

[0001] This application claims priority to Chinese patent application No. 202311212706.X filed on September 19, 2023, and priority to Chinese patent application No. 202322522509.X filed on September 15, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present disclosure relates to the technical field of air conditioning equipment, and in particular to an air conditioning system. Background Art

[0003] With the continuous advancement of technology and the improvement of people's living standards, air conditioners have become an indispensable electrical appliance in daily life.

[0004] A multi-split air conditioning system is used to provide heating and cooling to a building or room. It typically consists of an outdoor unit and multiple indoor units. Each indoor unit can independently control the temperature, allowing multiple units to be installed in different rooms or areas to meet the needs of different rooms.

[0005] Summary of the Invention

[0006] An air conditioning system is provided, comprising a compressor, a first heat exchanger, a second heat exchanger, at least one indoor unit, a detection unit, and a control unit. The first heat exchanger is connected to the compressor and configured to exchange heat between refrigerant discharged from the compressor and outdoor air. The second heat exchanger is connected to the compressor and configured to exchange heat between refrigerant discharged from the compressor and water. Any of the at least one indoor unit includes an indoor heat exchanger; the indoor heat exchanger is connected to the first heat exchanger via a first pipe and a third pipe, and to the second heat exchanger via a first pipe and a fourth pipe. The detection unit is connected to the at least one indoor unit and configured to detect the refrigerant concentration in the space where the indoor heat exchanger is located. The control unit is connected to the detection unit and configured to determine whether the refrigerant concentration detected by the detection unit is higher than a preset threshold; and when the refrigerant concentration is higher than the preset threshold, determine that a refrigerant leak has occurred and control the air conditioning system to enter a refrigerant recovery mode. The air conditioning system also includes a first throttling device and a second throttling device. The first throttling device is disposed on the third pipe. The second throttling device is disposed on the fourth pipeline. The control unit is further configured to: when the air conditioning system executes the refrigerant recovery mode, correct the opening of the first throttling device based on a difference between the temperatures of the refrigerants in the third pipeline and the fourth pipeline; correct the opening of the second throttling device based on a difference between the temperatures of the refrigerants in the fourth pipeline and the third pipeline; and control the openings of the first throttling device and the second throttling device in the refrigerant recovery mode so that the openings do not exceed a preset range. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG1 is a structural diagram of an air conditioning system according to some embodiments;

[0008] FIG2 is another structural diagram of an air conditioning system according to some embodiments;

[0009] FIG3 is a control flow chart of a control unit in an air-conditioning system according to some embodiments;

[0010] FIG4 is another control flow chart of a control unit in an air-conditioning system according to some embodiments;

[0011] FIG5 is another control flow chart of a control unit in an air-conditioning system according to some embodiments;

[0012] FIG6 is another control flow chart of a control unit in an air-conditioning system according to some embodiments;

[0013] FIG7 is another control flow chart of a control unit in an air-conditioning system according to some embodiments;

[0014] FIG8 is another control flow chart of a control unit in an air-conditioning system according to some embodiments;

[0015] FIG9 is another control flow chart of a control unit in an air-conditioning system according to some embodiments;

[0016] FIG10 is another control flow chart of a control unit in an air-conditioning system according to some embodiments;

[0017] FIG11 is a structural diagram of another air conditioning system according to some embodiments;

[0018] FIG12 is a structural diagram of yet another air conditioning system according to some embodiments;

[0019] FIG13 is a structural diagram of another air conditioning system according to some embodiments;

[0020] FIG14 is a structural diagram of another air conditioning system in a cooling mode according to some embodiments;

[0021] FIG15 is a structural diagram of another air conditioning system in a heating mode according to some embodiments;

[0022] FIG16 is a structural diagram of another air-conditioning system (in cooling mode) before refrigerant storage according to some embodiments;

[0023] FIG17 is a structural diagram of another air-conditioning system (in cooling mode) during refrigerant storage according to some embodiments;

[0024] FIG18 is a structural diagram of another air-conditioning system (in heating mode) before refrigerant storage according to some embodiments;

[0025] FIG19 is a structural diagram of another air-conditioning system (in heating mode) during refrigerant storage according to some embodiments;

[0026] FIG20 is a structural diagram of yet another air conditioning system (in cooling mode) before refrigerant release according to some embodiments;

[0027] FIG21 is a structural diagram of another air-conditioning system (in cooling mode) according to some embodiments when refrigerant is released;

[0028] FIG22 is a structural diagram of another air-conditioning system (in heating mode) before refrigerant release according to some embodiments;

[0029] FIG. 23 is a structural diagram of yet another air conditioning system (in heating mode) during refrigerant release according to some embodiments. DETAILED DESCRIPTION

[0030] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the embodiments described are only some embodiments of the present disclosure, not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0031] 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.

[0032] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly specifying the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of some embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0033] When describing some embodiments, the word "connected" and its derivatives may be used. The term "connected" should be understood in a broad sense. For example, "connected" can mean fixed connection, detachable connection, or integration; it can be directly connected or indirectly connected through an intermediate medium.

[0034] “At least one of A, B and C” has the same meaning as “at least one of A, B or C” and both include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.

[0035] As used herein, the term "if" is optionally interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined that" or "if [stated condition or event] is detected" are optionally interpreted to mean "upon determining" or "in response to determining" or "upon detecting [stated condition or event]" or "in response to detecting [stated condition or event]," depending on the context.

[0036] The use of "adapted to" or "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0037] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0038] R290 and R32 are often used as refrigerants in air conditioning systems due to their low ozone depletion potential and minimal environmental impact. R290 and R32 offer excellent refrigeration properties, such as high latent heat, which allows for efficient cooling or heating. However, R290 and R32 are flammable gases. If refrigerant leaks occur indoors during use in an air conditioning system and accumulates to a certain concentration, an explosion could occur.

[0039] Typically, to prevent refrigerant leaks, air conditioning systems are equipped with a built-in refrigerant detection device. This device can be used to detect the refrigerant concentration in the indoor environment. When the refrigerant detection device detects that the refrigerant concentration in the indoor environment has reached a certain threshold, the air conditioning system controller controls the four-way valve (i.e., the indoor heat exchanger operates as an evaporator), controls the operation of the compressor, and adjusts the opening of the throttling device to convert the gaseous refrigerant into liquid refrigerant, which is then collected outdoors.

[0040] It is understandable that the structure or method for recovering leaked refrigerant in the above-mentioned air-conditioning system is only applicable to split-type air conditioners (i.e., including one indoor unit and one outdoor unit). The refrigerant capacity in a split-type air conditioner is relatively small, and the above-mentioned structure or method can be used to recover the refrigerant to prevent an explosion. However, the above-mentioned structure or method is not applicable to a multi-split air-conditioning system (such as a heat pump air-conditioning system). A multi-split air-conditioning system includes multiple indoor units, and the pipes used to connect the multiple indoor units and outdoor units are relatively long. Therefore, the capacity of the refrigerant in the multi-split air-conditioning system is relatively large. In addition, the condensing capacity of multiple condensers in a multi-split air-conditioning system may be different. Therefore, in the process of recovering the refrigerant, if only the throttling device is used for adjustment, one condenser may be filled with liquid refrigerant too early, resulting in a decrease in the condensing capacity of the condenser, and further resulting in recovery failure.

[0041] To this end, the present disclosure provides an air conditioning system 1. Air conditioning system 1 can be installed in buildings such as apartments, hotels, office buildings, and residences, and is configured to perform at least one of increasing the temperature of the air within the building, decreasing the temperature of the air within the building, and supplying hot water. Air conditioning system 1 is a multi-split air conditioning system. For example, a multi-split air conditioning system is a heat pump air conditioning system.

[0042] In some embodiments, as shown in FIG1 , an air conditioning system 1 includes an indoor unit 100, an outdoor unit 200, and a refrigerant pipeline 300 connected between the indoor unit 100 and the outdoor unit 200. The refrigerant pipeline 300 is configured to circulate a refrigerant. The refrigerant is a flammable refrigerant, for example, R290 or R32.

[0043] The indoor unit group 100 includes at least one indoor unit, and the outdoor unit group 200 includes at least one outdoor unit. For example, referring to FIG. 1 , the at least one indoor unit includes a first indoor unit 110 and a second indoor unit 120 , and the at least one outdoor unit includes an outdoor unit 210 .

[0044] It should be noted that the indoor unit and outdoor unit shown in FIG1 are only examples, and the number of indoor units and outdoor units can be set according to actual needs, which is not limited in this disclosure.

[0045] The following describes the structure and principles of the air conditioning system 1 using the first indoor unit 110, the second indoor unit 120, and the outdoor unit 210 as examples. Unless otherwise specified, the first indoor unit 110 or the second indoor unit 120 has the same structure as any one of the at least one indoor unit, and the outdoor unit 210 has the same structure as any one of the at least one outdoor unit.

[0046] 2 , the refrigerant circuit 300 includes a first circuit 310 and a second circuit 320. One end of the first indoor unit 110 and the second indoor unit 120 is connected to one end of the outdoor unit 210 via the first circuit 310, and the other end of the first indoor unit 110 and the second indoor unit 120 is connected to the other end of the outdoor unit 210 via the second circuit 320.

[0047] In some embodiments, as shown in FIG. 2 , the refrigerant line 300 further includes a first shutoff valve 330 and a second shutoff valve 340 .

[0048] The first shutoff valve 330 is disposed on the first pipeline 310 and is configured to allow or block the flow of refrigerant in the first pipeline 310 by adjusting its opening. The second shutoff valve 340 is disposed on the second pipeline 320 and is configured to allow or block the flow of refrigerant in the second pipeline 320 by adjusting its opening.

[0049] In some embodiments, as shown in FIG2 , the outdoor unit 210 includes a compressor 211, a first heat exchanger 212, and a first throttling device 217. The indoor unit 100 includes an indoor heat exchanger (e.g., the third heat exchanger 111 in the first indoor unit 110 and the fourth heat exchanger 121 in the second indoor unit 120). The compressor 211 is configured to suck in refrigerant and compress it into a high-temperature, high-pressure refrigerant. The first throttling device 217 is configured to reduce the pressure of the refrigerant and cause it to expand. The opening degree of the first throttling device 217 is adjustable.

[0050] For example, the first throttling device 217 is an expansion valve.

[0051] For example, the first heat exchanger 212 is an air-side outdoor heat exchanger.

[0052] It should be noted that some embodiments of the present disclosure do not limit the type and number of compressors. For example, the compressor 211 can be a reciprocating compressor, a screw compressor, etc. The outdoor unit 210 can include one or more compressors 211.

[0053] Air conditioning system 1 is configured to operate in either a cooling mode or a heating mode. For example, the cooling mode and the heating mode of air conditioning system 1 can be achieved by the coordinated operation of a compressor 211, a condenser, a first throttling device 217, and an evaporator connected in sequence. The cooling mode and the heating mode involve a series of processes, including compression, condensation, expansion, and evaporation, to cool or heat the indoor space.

[0054] For example, when air conditioning system 1 is operating in cooling or heating mode, low-temperature, low-pressure refrigerant enters compressor 211, where it is compressed into a high-temperature, high-pressure gaseous refrigerant and discharged to the condenser. The condenser condenses the high-temperature, high-pressure gaseous refrigerant into a high-temperature, high-pressure liquid refrigerant. During the condensation process, the refrigerant releases heat into the surrounding environment.

[0055] Next, the high-temperature, high-pressure liquid refrigerant enters the first throttling device 217, where it expands into a low-pressure liquid refrigerant and enters the evaporator. The evaporator evaporates the expanded refrigerant, reducing its temperature and pressure, transforming it into a low-temperature, low-pressure gaseous refrigerant. The low-temperature, low-pressure gaseous refrigerant returns to the compressor 211 for the next cycle.

[0056] During the evaporation process, the evaporator can utilize the latent heat of evaporation of the refrigerant to exchange heat with the material to be cooled (such as water or air) to achieve a cooling or heating effect.

[0057] For example, when the air conditioning system 1 performs cooling mode, the first heat exchanger is used as a condenser and the indoor heat exchanger is used as an evaporator. When the air conditioning system 1 performs heating mode, the indoor heat exchanger is used as a condenser and the first heat exchanger is used as an evaporator.

[0058] In some embodiments, the air conditioning system 1 is further configured to execute a ventilation mode, a dehumidification mode, an air circulation mode, or the like.

[0059] For example, when the air conditioning system 1 operates in ventilation mode, it draws outside air into the room without heating or cooling it, thereby helping to maintain indoor air circulation. When the air conditioning system 1 operates in dehumidification mode, it removes moisture from the air, thereby lowering indoor humidity without lowering the indoor temperature. When the air conditioning system 1 operates in circulation mode, it circulates indoor air. In this case, the air conditioning system does not draw outside air into the room, thereby maintaining a stable indoor temperature.

[0060] In some embodiments, the air conditioning system 1 may also operate in other modes, which are not limited in this disclosure.

[0061] In some embodiments, the outdoor unit 210 further includes a gas-liquid separator 214 and a four-way valve 216. The gas-liquid separator 214 is provided on the suction side of the compressor 211 and is configured to separate gaseous refrigerant from liquid refrigerant and store excess refrigerant.

[0062] The four-way valve 216 is respectively connected to the indoor heat exchanger, the first heat exchanger 212, the compressor 211, and the gas-liquid separator 214. The four-way valve 216 is configured to: connect the first heat exchanger 212 and the gas-liquid separator 214, and connect the indoor heat exchanger and the compressor 211 in heating mode; and connect the first heat exchanger 212 and the compressor 211, and connect the indoor heat exchanger and the gas-liquid separator 214 in cooling mode.

[0063] In some embodiments, the refrigerant pipeline 300 further includes a third pipeline 350. One end of the third pipeline 350 is connected to the first pipeline 310, and the other end of the third pipeline 350 is connected to the first heat exchanger 212. The first throttling device 217 is disposed on the third pipeline 350.

[0064] When the air-conditioning system 1 operates in heating mode, the refrigerant flows from the first pipeline 310 to the third pipeline 350, passes through the first throttling device 217 on the third pipeline 350, and flows sequentially through the first heat exchanger 212, the four-way valve 216, the gas-liquid separator 214, and the compressor 211. It then passes through the four-way valve 216 again and flows into the second pipeline 320. The refrigerant in the second pipeline 320 then flows into the indoor heat exchanger and re-enters the first pipeline 310.

[0065] When the air conditioning system 1 operates in cooling mode, the refrigerant flows from the second pipeline 320 through the four-way valve 216, the gas-liquid separator 214, and the compressor 211 in sequence, and returns to the four-way valve 216. The refrigerant then passes through the first heat exchanger 212, enters the third pipeline 350, and the first throttling device 217. Finally, the refrigerant enters the first pipeline 310 through the first throttling device 217, passes through the indoor heat exchanger, and returns to the second pipeline 320, completing the next cycle.

[0066] In some embodiments, as shown in FIG2 , the air conditioning system 1 is further configured to operate in a hot water supply mode. The outdoor unit 210 further includes a second heat exchanger 213 . The second heat exchanger 213 is a water-side outdoor heat exchanger. The air conditioning system 1 further includes a first branch 410 and a second branch 420 . The first branch 410 includes a first temperature sensor 411 configured to detect the temperature of the water in the first branch 410 . The second branch 420 includes a second temperature sensor 421 configured to detect the temperature of the water in the second branch 420 .

[0067] The second heat exchanger 213 is connected to the first branch 410 and the second branch 420, and is configured to: exchange heat between water from the first branch 410 and the refrigerant in the second heat exchanger 213, store the heated water in the water tank, and guide the heated water to the water use area through the second branch 420.

[0068] For example, the air conditioning system 1 further includes a water pump 430 , which is disposed on the second branch 420 and configured to deliver hot water to the water-using area.

[0069] Air conditioning system 1 further includes a fourth pipeline 360. One end of fourth pipeline 360 ​​is connected to first pipeline 310 and third pipeline 350, respectively, and the other end of fourth pipeline 360 ​​is connected to second heat exchanger 213. In other words, the indoor heat exchanger is connected to first heat exchanger 212 via first pipeline 310 and third pipeline 350, and is connected to second heat exchanger 213 via first pipeline 310 and fourth pipeline 360.

[0070] The outdoor unit further includes a second throttling device 218, which is disposed on the fourth pipe 360 ​​and is configured to reduce the pressure of the refrigerant flowing through the second throttling device 218 and expand it. The opening degree of the second throttling device 218 is adjustable. For example, the second throttling device 218 is an expansion valve (e.g., an electronic expansion valve).

[0071] When air conditioning system 1 is in hot water supply mode, second heat exchanger 213 functions as a condenser. Second heat exchanger 213 can exchange heat with water flowing in first branch 410 and second branch 420. The refrigerant passes through compressor 211, second heat exchanger 213, fourth pipeline 360, second throttling device 218, gas-liquid separator 214, and returns to compressor 211.

[0072] 2 , the outdoor unit 210 further includes an outdoor fan 215. The outdoor fan 215 is disposed at the location of the first heat exchanger 212 and is configured to provide airflow to the first heat exchanger 212 so that the airflow exchanges heat with the refrigerant flowing in the first heat exchanger 212, causing the refrigerant to undergo a phase change (condensation or evaporation).

[0073] In some embodiments, the speed of the outdoor fan 215 is controllable. The outdoor fan 215 is further configured to adjust the speed to change the flow rate of the air heat-exchanged with the first heat exchanger 212.

[0074] It should be noted that some embodiments of the present disclosure do not limit the type of the outdoor fan 215. For example, the outdoor fan 215 can be an axial flow fan, a cross flow fan, etc.

[0075] In some embodiments, the outdoor unit 210 further includes an outdoor control circuit. This circuit is housed in an electrical box that has good sealing and heat dissipation properties. The outdoor control circuit includes components such as a processor, memory, input and output interfaces, and a communication interface.

[0076] The processor may be a dedicated processor, a central processing unit (CPU), etc. The processor may access the memory to execute instructions or applications stored in the memory to implement related functions. The memory may include at least one of a transient readable storage medium or a non-transitory readable storage medium.

[0077] The outdoor unit 200 further includes a plurality of outdoor sensors 230 . The input interface and the output interface are configured to be communicatively connected with the plurality of outdoor sensors 230 to receive detection values ​​from the plurality of outdoor sensors 230 .

[0078] For example, the plurality of outdoor sensors 230 include a third temperature sensor 231 , a first pressure sensor 232 , a second pressure sensor 233 , a fourth temperature sensor 234 , a fifth temperature sensor 235 , and the like.

[0079] For example, the third temperature sensor 231 is configured to detect the temperature of the compressor exhaust gas, the fourth temperature sensor 234 is configured to detect the temperature of the third pipeline, and the fifth temperature sensor 235 is configured to detect the temperature of the fourth pipeline.

[0080] For example, the first pressure sensor 232 is configured to detect the suction pressure of the compressor, and the second pressure sensor 233 is configured to detect the discharge pressure of the compressor.

[0081] The input interface and the output interface are also configured to communicate with devices such as the frequency converter, the compressor 211, the outdoor fan 215, the four-way valve 216, the first throttling device 217, the second throttling device 218, etc., so as to output the control instructions generated by the processor to these devices.

[0082] The communication interface can support multiple wireless communication protocols, such as Wi-Fi (Wireless Fidelity), Bluetooth, Near Field Communication, NB-IoT (Narrowband Internet of Things), etc., to communicate with other electronic devices.

[0083] Hereinafter, the structure and function of the indoor unit will be described in detail by taking the first indoor unit 110 as an example. It should be noted that the following description is also applicable to other indoor units (such as the second indoor unit 120).

[0084] As shown in Figure 2, the first indoor unit 110 can use the heat or cold provided by the outdoor unit 210 to perform cooling mode or heating mode. The first indoor unit 110 includes a third heat exchanger 111 and a third throttling device 112 connected in series. The refrigerant in the third heat exchanger 111 exchanges heat with the air, causing the refrigerant in the third heat exchanger 111 to undergo a phase change (condensation or evaporation). The third throttling device 112 is configured to reduce the pressure of the refrigerant flowing through the third throttling device 112 and expand it. The opening degree of the third throttling device 112 is adjustable. For example, the third throttling device 112 is an expansion valve.

[0085] In some embodiments, the first indoor unit 110 includes an indoor fan 113. The indoor fan 113 is disposed adjacent to the third heat exchanger 111 and is configured to output airflow to the third heat exchanger 111, exchange heat between the airflow and the refrigerant in the third heat exchanger 111, and output the heat-exchanged airflow indoors. For example, the indoor fan 113 may be an axial flow fan or a cross-flow fan, etc., although this disclosure is not limited thereto.

[0086] For example, in the heating mode, the third heat exchanger 111 is used as a condenser, and in the cooling mode, the third heat exchanger 111 is used as an evaporator.

[0087] In some embodiments, the first indoor unit 110 includes at least one of a wall-mounted air supply structure, a floor-standing air supply structure, a ducted air supply structure, and an air supply structure embedded in a ceiling. The air supply structure includes a housing, a return air vent for drawing air in, and an air supply vent for delivering the heat-exchanged air into the room.

[0088] In some embodiments, the first indoor unit 110 is further configured to communicate with at least one of a wired controller, a remote controller, or a mobile control terminal. A user can control the indoor unit via the wired controller, the remote controller, or the mobile control terminal, such as inputting a set temperature, switching modes, displaying real-time temperature, and displaying operating status.

[0089] For example, mobile control terminals include computers, tablets, smartphones, and wearable devices.

[0090] In some embodiments, the first indoor unit 110 includes an indoor control circuit. The indoor control circuit is housed in a sealed, heat-dissipating electrical box. The indoor control circuit includes components such as a processor, memory, input and output interfaces, and a communication interface.

[0091] It should be noted that the processor, memory, input interface, output interface, communication interface and other components in the indoor control circuit have roughly the same structure and function as the processor, memory, communication interface and other components in the outdoor control circuit, and this disclosure will not go into details.

[0092] The indoor unit 100 includes a plurality of indoor sensors 130. The input interface and the output interface of the indoor control circuit are configured to connect to the plurality of indoor sensors 130.

[0093] For example, the plurality of indoor sensors 130 include a concentration sensor 131 , a sixth temperature sensor 132 , and a seventh temperature sensor 133 .

[0094] The concentration sensor 131 is configured to detect the concentration of the flammable refrigerant in the indoor space. The sixth temperature sensor 132 is configured to detect the temperature of the first pipe 310 , and the seventh temperature sensor 133 is configured to detect the temperature of the second pipe 320 .

[0095] Hereinafter, the cooling mode, heating mode and hot water supply mode of the air-conditioning system 1 will be described in detail with reference to FIG. 2 .

[0096] As shown in Figure 2, when the air conditioning system 1 is operating in cooling mode, the first shutoff valve 330 and the second shutoff valve 340 remain open. Low-pressure gaseous refrigerant is drawn into the compressor 211, where it is compressed into high-temperature, high-pressure refrigerant. The high-temperature, high-pressure refrigerant then enters the first heat exchanger 212 via the four-way valve 216, where it undergoes heat exchange with air guided by the outdoor fan 215, transforming into high-pressure liquid refrigerant. The high-pressure liquid refrigerant is then reduced in pressure by the first throttle device 217, the third throttle device 112, and the fourth throttle device 122, transforming into a low-pressure gas-liquid two-phase refrigerant or a low-pressure liquid refrigerant. The refrigerant then enters the third heat exchanger 111 of the first indoor unit 110 and the fourth heat exchanger 121 of the second indoor unit 120.

[0097] The low-pressure refrigerant entering the third heat exchanger 111 and the fourth heat exchanger 121 evaporates in the third heat exchanger 111 and the fourth heat exchanger 121, transforms into a low-pressure gaseous refrigerant, and flows out of the third heat exchanger 111 and the fourth heat exchanger 121. Then, the low-pressure gaseous refrigerant passes through the second pipeline 320, the four-way valve 216, the gas-liquid separator 214, and is sucked into the compressor 211 again, entering the next round of refrigeration cycle.

[0098] It should be noted that when the air conditioning system 1 is operating in cooling mode, the high-temperature, high-pressure refrigerant can simultaneously enter the second heat exchanger 213 upon entering the first heat exchanger 212. In the second heat exchanger 213, the high-temperature, high-pressure refrigerant exchanges heat with the cold water from the first branch 410, raising the temperature of the cold water, i.e., converting it into hot water. The hot water is then transported to the water consumption end via the second branch 420 to supply hot water to the user. This allows for simultaneous cooling and hot water supply.

[0099] As shown in Figure 2, when the first indoor unit 110 is operating in heating mode, the first and second shutoff valves 330 and 340 remain open. Low-pressure gaseous refrigerant is drawn into the compressor 211 and compressed into high-temperature, high-pressure refrigerant. The high-temperature, high-pressure gaseous refrigerant passes through the four-way valve 216 and the second pipeline 320 and enters the third and fourth heat exchangers 111 and 121. The high-temperature, high-pressure gaseous refrigerant is condensed in the third and fourth heat exchangers 111 and 121, transforming into high-pressure liquid refrigerant before flowing out of the third and fourth heat exchangers 111 and 121.

[0100] Next, the high-pressure liquid refrigerant is reduced in pressure by the third and fourth throttle devices 112 and 122, and by the first throttle device 217, becoming a low-pressure gas-liquid two-phase refrigerant. The refrigerant then enters the first heat exchanger 212. In the first heat exchanger 212, the low-pressure gas-liquid two-phase refrigerant exchanges heat with the air guided by the outdoor fan 215, becoming a low-pressure gas refrigerant. Finally, the low-pressure gas refrigerant passes through the four-way valve 216 and the gas-liquid separator 214, and re-enters the compressor 211.

[0101] It should be noted that when the air-conditioning system 1 is in heating mode, the high-temperature and high-pressure refrigerant can enter the second heat exchanger 213 simultaneously when entering the third heat exchanger 111 and the fourth heat exchanger 121, so as to realize hot water supply while achieving heating.

[0102] In some embodiments, the air conditioning system 1 further includes a detection unit 12 and a control unit 13 .

[0103] The detection unit 12 is configured to detect the concentration of the refrigerant in the indoor space (the space where the indoor heat exchanger is located).

[0104] For example, the detection unit 12 includes a concentration sensor, and the detection unit 12 may detect the concentration of the refrigerant in the indoor space through the concentration sensor.

[0105] The control unit 13 is configured to: determine whether the concentration detected by the detection unit 12 is higher than a preset threshold; and when the refrigerant concentration in the indoor space exceeds the preset threshold, determine that the refrigerant has leaked and control the air conditioning system 1 to execute the refrigerant recovery mode.

[0106] For example, when the air conditioning system 1 includes multiple indoor units, the control unit 13 is further configured to: when the detection unit 12 determines that there is refrigerant leakage in the indoor space where any indoor heat exchanger is located, control the air conditioning system 1 to execute the refrigerant recovery mode.

[0107] In some embodiments, the functions of the control unit 13 are performed by at least one of an indoor control circuit or an outdoor control circuit.

[0108] When the air conditioning system 1 executes the refrigerant recovery mode, the controller 13 controls the compressor 211 to operate so as to recover the refrigerant in the first indoor unit 110 to the outdoor side, thereby preventing the refrigerant from exploding indoors.

[0109] However, the first heat exchanger 212 and the second heat exchanger 213 have different condensing capacities. Therefore, when the air-conditioning system 1 executes the refrigerant recovery mode, one of the outdoor heat exchangers may be filled with liquid prematurely.

[0110] "Liquid full" means the condenser is filled with liquid refrigerant. In this case, the pressure in the high-pressure section of air conditioning system 1 can rise, even exceeding the design range. Compressor 211 can be subjected to an abnormal workload, causing it to shut down. However, the refrigerant is not completely recovered at this point, and flammable refrigerant remains in the indoor space, posing a safety hazard.

[0111] Based on this, as shown in FIG3 , the control unit 13 is further configured to execute steps S101 to S104 to ensure that the openings of the first throttling device 217 and the second throttling device 218 are similar in the refrigerant recovery mode, thereby causing the refrigerant liquid levels in the first heat exchanger 212 and the second heat exchanger 213 to rise at similar rates and remain at similar levels. This allows the refrigerant storage capacity of the first heat exchanger 212 and the second heat exchanger 213 to be fully utilized, ensuring that the refrigerant on the indoor side is recovered to the outdoor side.

[0112] In step S101 , the air conditioning system 1 is controlled to execute a refrigerant recovery mode.

[0113] In step S102 , the opening degree of the first throttle device 217 is adjusted based on the difference in refrigerant temperature in the third pipe 350 and the fourth pipe 360 ​​.

[0114] For example, the fourth temperature sensor 234 is disposed between the first heat exchanger 212 and the first throttling device 217 .

[0115] In step S103 , the opening degree of the second throttling device 218 is adjusted based on the difference in refrigerant temperature between the fourth pipe 360 ​​and the third pipe 350 .

[0116] For example, the fifth temperature sensor 235 is disposed between the second heat exchanger 213 and the second throttling device 218 .

[0117] In step S104 , the opening changes of the first throttling device 217 and the second throttling device 218 are controlled so as not to exceed a preset range.

[0118] It should be noted that the preset range can be 0 to C. C is a constant greater than 0 and is pre-written to the memory by a technician. Thus, when the refrigerant recovery mode is executed, the opening of the first throttling device 217 and the opening of the second throttling device 218 are similar, which is conducive to improving the refrigerant recovery effect.

[0119] In some embodiments, C is any value between 0 and 0.5, for example, C is 0.01, 0.05, 0.1, 0.2, or 0.5.

[0120] It is understood that when the value of C is small (such as C is 0), the opening of the first throttling device 217 and the second throttling device 218 can be made to change less during the refrigerant recovery process, thereby facilitating improved stability of refrigerant recovery. When the value of C is large (such as C is 0.5), the opening of the first throttling device 217 and the second throttling device 218 can be made to change to a similar opening during the refrigerant recovery process, thereby facilitating improved refrigerant recovery efficiency.

[0121] In some embodiments, as shown in FIG4 , the control unit 13 is further configured to execute steps S201 to S203 .

[0122] In step S201 , the air conditioning system 1 is controlled to execute a refrigerant recovery mode.

[0123] In step S202 , an air-side adjustment proportional coefficient is calculated based on the temperature difference between the refrigerant in the third pipe 350 and the refrigerant in the fourth pipe 360 ​​.

[0124] For example, the air-side adjustment proportional coefficient is a ratio of the first set constant to the temperature difference between the flammable refrigerant in the third pipeline 350 and the fourth pipeline 360 ​​.

[0125] In step S203 , the product of the air-side adjustment proportional coefficient and the opening of the first throttling device 217 in the current adjustment cycle is used as the opening of the first throttling device 217 in the next adjustment cycle.

[0126] It should be noted that the opening degree of the first throttling device 217 in the next adjustment cycle is less than or equal to the opening degree of the first throttling device 217 in the current adjustment cycle.

[0127] In some embodiments, the opening degree of the first throttling device 217 in the next regulation cycle can be obtained by formula (1). EVO(n)=EVO(n-1)×c1 / (T e -T rl ); (1)

[0128] In formula (1), EVO(n) is the opening degree of the first throttling device 217 in the next adjustment cycle, EVO(n-1) is the opening degree of the first throttling device 217 in the current adjustment cycle, T e is the refrigerant temperature of the third pipe 350 (ie, the pipe temperature of the third pipe 350), T rl is the refrigerant temperature of the fourth pipe 360 ​​(ie, the pipe temperature of the fourth pipe 360 ​​), c1 is a first set constant, and c1 is any value between 2 and 5, that is, 2≤c1≤5; c1 / (T e -T rl ) is the air side adjustment proportional coefficient.

[0129] In some embodiments, as shown in FIG5 , the control unit 13 is further configured to execute steps S301 to S303 .

[0130] In step S301 , the air conditioning system 1 is controlled to execute a refrigerant recovery mode.

[0131] In step S302 , a water-side adjustment proportional coefficient is calculated based on the refrigerant temperature difference between the fourth pipeline 360 ​​and the third pipeline 350 .

[0132] For example, the water-side adjustment proportional coefficient is a ratio of the second set constant to the temperature difference between the flammable refrigerant in the fourth pipeline 360 ​​and the third pipeline 350 .

[0133] In step S303, the product of the water-side regulation proportional coefficient and the opening of the second throttling device 218 in the current regulation cycle is used as the opening in the next regulation cycle.

[0134] It should be noted that the opening degree of the second throttling device 218 in the next adjustment cycle is less than or equal to the opening degree of the second throttling device 218 in the current adjustment cycle.

[0135] In some embodiments, the opening degree of the second throttling device 218 in the next regulation cycle can be obtained by formula (2). EVw(n)=EVw(n-1)×c2 / (T rl -T e ); (2)

[0136] In formula (2), EVw(n) is the opening degree of the second throttling device 218 in the next adjustment cycle, EVw(n-1) is the opening degree of the second throttling device 218 in the current adjustment cycle, T e is the refrigerant temperature of the third pipe 350 (ie, the pipe temperature of the third pipe 350), T rl is the refrigerant temperature of the fourth pipe 360 ​​(ie, the pipe temperature of the fourth pipe 360), c2 is the second set constant, and c2 is any value between 2 and 5, that is, 2≤c2≤5. c2 / (Trl -T e ) is the water side regulation proportional coefficient.

[0137] In some embodiments, the first setting constant c1 is equal to the second setting constant c2.

[0138] It is understandable that, since the working fluid in the air-conditioning system 1 is more sensitive to temperature changes, when temperature is used as a parameter, the components in the air-conditioning system 1 respond quickly, thereby producing more stable test conditions.

[0139] In addition, the temperature is used to calculate the air side adjustment proportional coefficient and the water side adjustment proportional coefficient to obtain the opening of the throttling device in the next adjustment cycle, so that the opening change of the throttling device in the refrigerant recovery mode can be accurately controlled, which is beneficial to improving the refrigerant recovery speed and can make the amount of liquid refrigerant stored in the two outdoor heat exchangers similar.

[0140] The following will describe in detail the adjustment process of the first throttling device 217 and the second throttling device 218 in conjunction with FIG. 6 and the process of the refrigerant recovery mode.

[0141] In some embodiments, as shown in FIG6 , the control unit 13 is further configured to execute steps S401 to S408 .

[0142] In step S401 , the air conditioning system 1 is controlled to execute a refrigerant recovery mode.

[0143] In step S402, the indoor heat exchanger is configured as an evaporator.

[0144] For example, when the refrigerant recovery mode is executed, if the indoor unit is in the cooling mode, no additional control is performed and the indoor heat exchanger is configured as an evaporator.

[0145] When the refrigerant recovery mode is executed, if the indoor unit is in the heating mode, the operation mode of the indoor unit is switched to the cooling mode, the indoor heat exchanger is configured as an evaporator, and the indoor unit is controlled to remain in the cooling mode for a first preset time. For example, the first preset time is any value between 0s and 90s (i.e., 0s ≤ first preset time < 90s).

[0146] In step S403 , the first shut-off valve 330 is controlled to be closed to cut off the fluid passage in the first pipeline 310 .

[0147] In step S404 , the first throttle device 217 is controlled to open to a first preset opening degree.

[0148] For example, the first preset opening can be the maximum opening to which the first throttling device 217 can be opened, or can be the working opening of the first throttling device 217 (which will be described in detail below).

[0149] In step S405 , the second throttle device 218 is controlled to open to a second preset opening degree.

[0150] For example, the second preset opening can be the maximum opening to which the second throttling device 218 can be opened, or can be the working opening of the second throttling device 218 (which will be described in detail below).

[0151] In step S406 , the third throttle device 112 and the fourth throttle device 122 are controlled to open to the maximum opening degree.

[0152] In this case, the control unit 13 is also configured to control the speed of the indoor fan to increase to a high wind gear, control the speed of the outdoor fan 215 to increase to a high wind gear, and control the water pump 430 to increase to a high speed gear, so as to increase the refrigerant recovery speed.

[0153] For example, in step S406, the refrigerant on the indoor side is recovered from the indoor heat exchanger to the indoor unit, then enters the four-way valve 216 through 320, and then enters the compressor 211 through 214. Then, part of the refrigerant is recovered to the first heat exchanger 212 through the four-way valve 216, and the other part of the refrigerant is recovered to the second heat exchanger 213.

[0154] In step S407 , based on the first preset opening, the opening of the first throttling device 217 is corrected based on the difference in temperature between the refrigerant in the third pipe 350 and the refrigerant in the fourth pipe 360 ​​.

[0155] In step S408 , based on the second preset opening, the opening of the second throttling device 218 is corrected based on the difference in temperature between the refrigerant in the fourth pipe 360 ​​and the refrigerant in the third pipe 350 .

[0156] It can be understood that, by correcting the first throttling device 217 and the second throttling device 218 in step S407 and step S408, the opening changes of the first throttling device 217 and the second throttling device 218 in the refrigerant recovery mode do not exceed the preset range.

[0157] That is, when executing the refrigerant recovery mode, EVO(n-1) and EVw(n-1) are both at the maximum opening, and are gradually corrected based on the air side adjustment proportional coefficient and the water side adjustment proportional coefficient within multiple adjustment cycles.

[0158] In some embodiments, the control unit 13 is further configured to control the air-conditioning system 1 to end the refrigerant recovery mode when the refrigerant on the indoor side is evacuated (eg, extracted to the outdoor side).

[0159] For example, as shown in FIG. 7 , after step S408 , the control unit 13 is further configured to execute step S409 .

[0160] In step S409 , when the pressure on the suction side of the compressor 211 is less than or equal to the preset pressure, the air conditioning system 1 is controlled to terminate the refrigerant recovery mode.

[0161] For example, the preset pressure is 0.2 MPa.

[0162] It can be understood that when the pressure on the suction side of the compressor 211 is greater than the warning condition, the control unit 13 controls the air-conditioning system 1 to continue to perform refrigerant recovery.

[0163] In some embodiments, as shown in FIG8 , step S409 includes steps S4091 to S4093 .

[0164] In step S4091 , the second shut-off valve 340 is controlled to cut off the fluid passage in the second pipeline 320 .

[0165] In step S4092, the compressor 211, the heat exchanger and other components are controlled to stop operating.

[0166] It is understandable that the closing of the second shut-off valve 340 needs to last for a certain period of time. Therefore, in order to avoid backflow of the refrigerant, it is necessary to control the compressor and other components to stop running only after the shut-off valve is closed.

[0167] In step S4093, the control room throttling device is closed to the minimum opening.

[0168] 9 , the control unit 13 is further configured to generate the operating openings of the first throttle device 217 and the second throttle device 218. The step of generating the operating openings of the first throttle device 217 and the second throttle device 218 includes steps S501 to S504.

[0169] In step S501 , it is determined whether the second heat exchanger 213 is configured as a condenser.

[0170] In step S502 , it is determined whether the first heat exchanger 212 is configured as a condenser. When the first heat exchanger 212 is configured as a condenser, step S503 is executed. When the first heat exchanger 212 is configured as an evaporator, step S504 is executed.

[0171] In step S503 , the operating opening of the second throttling device 218 is generated according to the subcooling degree at the outlet of the second heat exchanger 213 , and the operating opening of the first throttling device 217 is generated according to the subcooling degree at the outlet of the first heat exchanger 212 .

[0172] For example, the degree of subcooling at the outlet of the second heat exchanger 213 can be calculated by the difference between the temperature of the fourth pipeline 360 ​​and the saturation temperature corresponding to the exhaust pressure of the compressor 211. The degree of subcooling at the outlet of the first heat exchanger 212 can be calculated by the difference between the temperature of the third pipeline 350 and the saturation temperature corresponding to the exhaust pressure of the compressor 211.

[0173] In step S504 , the operating opening of the second throttling device 218 is generated according to the degree of subcooling at the outlet of the second heat exchanger 213 , and the operating opening of the first throttling device 217 is generated according to the degree of exhaust gas superheat of the compressor 211 .

[0174] For example, the degree of subcooling at the outlet of the second heat exchanger 213 can be calculated by the difference between the temperature of the fourth pipeline 360 ​​and the saturation temperature corresponding to the exhaust pressure of the compressor 211, and the exhaust superheat of the compressor 211 can be calculated by the difference between the exhaust temperature of the compressor 211 and the saturation temperature corresponding to the exhaust pressure of the compressor 211.

[0175] It can be understood that when the second throttling device 218 and the first throttling device 217 are opened to the working opening, the indoor throttling device can control the subcooling degree of the indoor unit, that is, the opening degree of the indoor throttling device is generated according to the difference between the detection value of the sixth temperature sensor and the saturation temperature corresponding to the exhaust pressure of the compressor 211.

[0176] In some embodiments, as shown in FIG10 , after step S104 , the air conditioning system 1 is further configured to perform step S105 .

[0177] In step S105 , the air conditioning system 1 is controlled to terminate the refrigerant recovery mode and to operate the emergency control mode.

[0178] It is understandable that when the weather is cold, the temperature of the indoor environment may drop to a level that makes the human body uncomfortable. In this case, when the air-conditioning system 1 can operate the emergency control mode to appropriately increase the indoor temperature, the user can wait for maintenance personnel to repair the air-conditioning system 1 in a suitable environment, which is conducive to improving the user experience.

[0179] The emergency control mode includes: configuring the second heat exchanger 213 as a condenser, controlling the second throttling device 218 to open to the maximum opening, and determining the emergency working opening of the first throttling device 217 according to the exhaust gas superheat of the compressor.

[0180] When air conditioning system 1 operates in emergency control mode, first shutoff valve 330 and second shutoff valve 340 remain closed. Low-pressure gaseous refrigerant is drawn into compressor 211 and compressed into high-temperature, high-pressure gaseous refrigerant. The high-temperature, high-pressure gaseous refrigerant enters second heat exchanger 213, where it undergoes heat exchange with the water in the first and second branches, transforming into high-pressure liquid refrigerant. The high-pressure liquid refrigerant exits second heat exchanger 213 via fourth line 360 ​​and then enters first heat exchanger 212. The refrigerant is decompressed by first throttling device 217, transforming into low-pressure gas-liquid two-phase refrigerant or low-pressure liquid refrigerant. The refrigerant then passes through four-way valve 216 and gas-liquid separator 214 before being drawn back into compressor 211.

[0181] It is understandable that in cold weather conditions, the emergency control mode can keep the temperature of the indoor environment from being too low, thereby helping to improve the user experience.

[0182] Some embodiments of the present disclosure further provide another air-conditioning system 1 , which is, for example, a multi-split air-conditioning system.

[0183] As shown in FIG11 , the air conditioning system 1 includes a plurality of indoor units 600 , one end of each of the indoor units 600 is connected to the outdoor unit 500 via a first pipe 310 , and the other end of each of the indoor units 600 is connected to the outdoor unit 500 via a second pipe 320 .

[0184] In some embodiments, the air conditioning system 1 further includes multiple third branches 730 and multiple fourth branches 740. The multiple third branches 730 and the multiple fourth branches 740 correspond to the multiple indoor units 600. Each of the multiple indoor units 600 includes an indoor heat exchanger. The indoor heat exchanger is connected to the first pipeline 310 via the corresponding third branch 730 and to the second pipeline 320 via the corresponding fourth branch 740.

[0185] In some embodiments, the air conditioning system 1 further includes a plurality of first shutoff valves 710, each of which corresponds to the plurality of third branches 730, and any one of the plurality of first shutoff valves 710 is disposed on a corresponding third branch 730. The first shutoff valve 710 is configured to switch between states to adjust the amount of refrigerant in the indoor heat exchanger of the corresponding indoor unit 600.

[0186] In some embodiments, the air conditioning system 1 further includes a plurality of second shutoff valves 720, the plurality of second shutoff valves 720 corresponding to the plurality of fourth branches 740, and any second shutoff valve 720 among the plurality of second shutoff valves 720 is disposed on a corresponding fourth branch 740. The second shutoff valve 720 is configured to switch between states to adjust the amount of refrigerant in the indoor heat exchanger of the corresponding indoor unit 600.

[0187] It can be understood that the air-conditioning system 1 in some embodiments of the present disclosure uses the first shut-off valve 710 and the second shut-off valve 720 to control the distribution of refrigerant in multiple indoor units, so that the air-conditioning system 1 can reasonably distribute refrigerant to multiple indoor units under a variety of different working conditions, while effectively avoiding flow noise.

[0188] For example, the amount of refrigerant that the air-conditioning system 1 needs to distribute to the plurality of indoor units may vary based on the indoor ambient temperature, the outdoor ambient temperature, the number of indoor units in operation, and the wind speed of the indoor fan.

[0189] In some embodiments, as shown in FIG12 , two indoor units 600 among the plurality of indoor units 600 are arranged in parallel and correspond to a third branch 730, a fourth branch 740, a first shutoff valve 710, and a second shutoff valve 720. The two indoor units 600 are connected to the first pipeline 310 via the third branch 730 and to the second pipeline 320 via the fourth branch 740.

[0190] The first shutoff valve 710 is provided on the third branch 730 and is configured to simultaneously adjust the amount of refrigerant in the indoor heat exchangers of the two indoor units 600 when both indoor units 600 are in the off state.

[0191] Correspondingly, the second shutoff valve 720 is provided on the fourth branch 740 and is configured to simultaneously adjust the amount of refrigerant in the indoor heat exchangers of the two indoor units 600 when both indoor units 600 are in the off state.

[0192] It is understood that in some embodiments, a third branch 730 may be configured to connect two or more indoor heat exchangers arranged in parallel to the first pipeline 310, and to simultaneously control the amount of refrigerant in the two or more indoor heat exchangers arranged in parallel through a first shut-off valve 710. Correspondingly, a fourth branch 740 may be configured to connect two or more indoor heat exchangers arranged in parallel to the second pipeline 320, and to control the amount of refrigerant in the two or more indoor heat exchangers arranged in parallel through a second shut-off valve 720 provided on the fourth branch 740.

[0193] In some embodiments, as shown in FIG. 13 , a plurality of first shutoff valves 710 are disposed on some of the third branches 730 , and a plurality of second shutoff valves 720 are disposed on some of the fourth branches 740 .

[0194] That is, the number of the first shutoff valves 710 is the same as the number of the second shutoff valves 720 , and the number of the first shutoff valves 710 may be less than or equal to the number of the indoor units 600 .

[0195] The following, with reference to the accompanying drawings, describes in detail the cooling and heating principles of the air conditioning system 1, taking an air conditioning system 1 including one outdoor unit 500 and two indoor units 600 (i.e., a first indoor unit 610 and a second indoor unit 620). It should be noted that the present disclosure does not limit the number of indoor and outdoor units.

[0196] 14 , the outdoor unit 500 includes an outdoor heat exchanger 510, a compressor 520, a gas-liquid separator 530, a four-way valve 540, and an outdoor expansion valve 550. The four-way valve 540 includes ports C, D, E, and S.

[0197] The plurality of third branches 730 include a first sub-branch 731 and a second sub-branch 732. The plurality of fourth branches 740 include a third sub-branch 741 and a fourth sub-branch 742. The first indoor unit 610 is connected to the first pipeline 310 and the second pipeline 320 via the first sub-branch 731 and the third sub-branch 741. The second indoor unit 620 is connected to the first pipeline 310 and the second pipeline 320 via the second sub-branch 732 and the fourth sub-branch 742.

[0198] The plurality of first cutoff valves 710 include a first sub-cutoff valve 711 and a second sub-cutoff valve 712. The first sub-cutoff valve 711 and the second sub-cutoff valve 712 are disposed on the first sub-branch 731 and the second sub-branch 732, respectively.

[0199] The plurality of second shut-off valves 720 include a third sub-shut-off valve 721 and a fourth sub-shut-off valve 722. The third sub-shut-off valve 721 and the fourth sub-shut-off valve 722 are disposed on the third sub-branch 741 and the fourth sub-branch 742, respectively.

[0200] The first indoor unit 610 includes a third heat exchanger 611 and a first indoor expansion valve 612. The first indoor expansion valve 612 is disposed on the first sub-branch 731 and connected to the third heat exchanger 611. The second indoor unit 620 includes a fourth heat exchanger 621 and a second indoor expansion valve 622. The second indoor expansion valve 622 is disposed on the second sub-branch 732 and connected to the fourth heat exchanger 621. For example, both the first indoor expansion valve 612 and the second indoor expansion valve 622 are electronic expansion valves.

[0201] When the air conditioning system 1 operates in cooling mode and both the first and second indoor units 610 and 620 are powered on, ports D and C of the four-way valve 540 are connected, and ports E and S are connected. The refrigerant flows in the direction indicated by the arrows in Figure 14 . The compressor 520 compresses the low-temperature, low-pressure gaseous refrigerant into high-temperature, high-pressure gaseous refrigerant, which is then discharged to the four-way valve 540. The high-temperature, high-pressure gaseous refrigerant then flows through the four-way valve 540 into the outdoor heat exchanger 510, where it is condensed into high-temperature, high-pressure liquid refrigerant. The high-temperature, high-pressure liquid refrigerant then passes through the outdoor expansion valve 550 and the first pipeline 310 before being split into two paths.

[0202] One refrigerant path passes through the first sub-branch 731 (with the first sub-blocking valve 711 open) and enters the first indoor expansion valve 612. It is throttled by the first indoor expansion valve 612 into a low-temperature, low-pressure liquid refrigerant. It then evaporates and absorbs heat in the third heat exchanger 611, transforming into a low-temperature, low-pressure gaseous refrigerant. Next, the low-temperature, low-pressure gaseous refrigerant flows through the third sub-branch 741 (with the third sub-blocking valve 721 open) into the second pipeline 320, passes through the four-way valve 540, enters the gas-liquid separator 530, and returns to the compressor 520. The compressor 520 compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant for the next refrigeration cycle.

[0203] The other refrigerant path passes through the second sub-branch 732 (with the second sub-blocking valve 712 open) and enters the second indoor expansion valve 622, where it is throttled into a low-temperature, low-pressure liquid refrigerant. The low-temperature, low-pressure liquid refrigerant is then evaporated into a low-temperature, low-pressure gaseous refrigerant in the fourth heat exchanger 621. The low-temperature, low-pressure gaseous refrigerant enters the second pipeline 320 through the fourth sub-branch 742 (with the fourth sub-blocking valve 722 open), then passes through the four-way valve 540 and the gas-liquid separator 530 and returns to the compressor 520. The compressor 520 compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant for the next refrigeration cycle.

[0204] As shown in Figure 15 , when the air conditioning system 1 is operating in heating mode and both the first indoor unit 610 and the second indoor unit 620 are powered on, ports D and E of the four-way valve 540 are connected, and ports C and S are connected. The refrigerant flows in the direction indicated by the arrows in Figure 15 . The compressor 520 compresses the low-temperature, low-pressure gaseous refrigerant into high-temperature, high-pressure gaseous refrigerant, which is then discharged through the four-way valve 540. After passing through the four-way valve 540, the high-temperature, high-pressure gaseous refrigerant enters the second pipeline 320 and is split into two paths.

[0205] One refrigerant path passes through the third sub-branch 741 (with the third sub-blocking valve 721 open) and enters the third heat exchanger 611, where it is condensed into a high-temperature, high-pressure liquid refrigerant. It then passes through the first indoor expansion valve 612, the first sub-branch 731 (with the first sub-blocking valve 711 open), the first pipeline 310, and the outdoor expansion valve 550, where it is throttled back to a low-temperature, low-pressure liquid refrigerant. The low-temperature, low-pressure liquid refrigerant then enters the outdoor heat exchanger 510, where it evaporates and absorbs heat, transforming into a low-temperature, low-pressure gaseous refrigerant. The low-temperature, low-pressure gaseous refrigerant then passes through the four-way valve 540 and the gas-liquid separator and returns to the compressor 520, where it is compressed into a high-temperature, high-pressure gaseous refrigerant, entering the next heating cycle.

[0206] The other refrigerant path passes through the fourth sub-branch 742 (with the fourth sub-blocking valve 722 open) and enters the fourth heat exchanger 621, where it is condensed into a high-temperature, high-pressure liquid refrigerant. It then passes through the second indoor expansion valve 622, the second sub-branch 732 (with the second sub-blocking valve 712 open), the second pipeline 320, and the outdoor expansion valve 550, where it is throttled back to a low-temperature, low-pressure liquid refrigerant. The low-temperature, low-pressure liquid refrigerant then evaporates and absorbs heat in the outdoor heat exchanger 510, transforming into a low-temperature, low-pressure gaseous refrigerant. The low-temperature, low-pressure gaseous refrigerant then returns to the compressor 520 via the four-way valve 540 and the gas-liquid separator, where it is compressed into a high-temperature, high-pressure gaseous refrigerant, entering the next heating cycle.

[0207] It is understandable that when either the first indoor unit 610 or the second indoor unit 620 is in the shutdown state, the corresponding first shut-off valve and the second shut-off valve are in the closed state, and the corresponding fourth branch 740 and the third branch 730 are shut off.

[0208] Thus, when the air conditioning system 1 is operating in cooling or heating mode, if the air conditioning system 1 is in a stable state, there is no need to regulate the distribution of the refrigerant, and the first and second shutoff valves corresponding to the indoor units in the off state can remain closed. If the air conditioning system 1 is in an unstable state, the first and second shutoff valves can be switched to an open state to connect the third branch 730 and the fourth branch 740, thereby directing part of the refrigerant to flow through the corresponding indoor expansion valve and be stored in the corresponding indoor heat exchanger.

[0209] In some embodiments, when the air conditioning system 1 operates in cooling mode, if the air conditioning system 1 satisfies at least one of the first preset condition, the second preset condition, and the third preset condition, the air conditioning system 1 is determined to be in an unstable state. Otherwise, the air conditioning system 1 is determined to be in a stable state.

[0210] For example, the first preset condition includes: the evaporation temperature Tl is greater than 13°C. The second preset condition includes: the exhaust pressure Pd of the compressor 520 is greater than or equal to 3.6 MPa. The third preset condition includes: the difference between the saturation temperature Tdc corresponding to the exhaust pressure of the compressor 520 and the outlet temperature Te of the outdoor heat exchanger 510 is greater than or equal to 15°C.

[0211] It should be noted that the evaporation temperature T1 refers to the temperature of the gas-liquid two-phase refrigerant on the low-pressure side (e.g., indoor side) of the refrigeration cycle of the air-conditioning system 1. For example, the evaporation temperature T1 is the temperature on the liquid pipe of the evaporator on the indoor side.

[0212] For example, the first preset condition includes: the opening degree of the outdoor expansion valve 550 is less than or equal to 50%. The second preset condition includes: the opening degree of any indoor expansion valve is greater than or equal to 90%. The third preset condition includes: the difference between the exhaust temperature Td of the compressor 520 and the saturation temperature Tdc corresponding to the exhaust pressure Pd is greater than or equal to 60°C.

[0213] In some embodiments, when the air conditioning system 1 operates in the heating mode, if the air conditioning system 1 satisfies at least one of the fourth preset condition, the fifth preset condition, and the sixth preset condition, the air conditioning system 1 is determined to be in an unstable state. Otherwise, the air conditioning system 1 is determined to be in a stable state.

[0214] For example, the fourth preset condition includes: the difference between the exhaust temperature Td of the compressor 520 and the saturation temperature Tdc corresponding to the exhaust pressure Pd of the compressor 520 is less than or equal to 20° C. The fifth preset condition includes: the difference between the saturation temperature Tdc corresponding to the exhaust pressure Pd of the compressor 520 and the evaporation temperature Tl is greater than 20° C. The sixth preset condition includes: the exhaust pressure Pd of the compressor 520 is greater than 3.4 MPa.

[0215] In some embodiments, when the air conditioning system 1 operates in the heating mode, if the air conditioning system 1 satisfies at least one of the seventh and eighth preset conditions, the air conditioning system 1 is determined to be in an unstable state. Otherwise, the air conditioning system 1 is determined to be in a stable state.

[0216] For example, the seventh preset condition includes: the difference between the saturation temperature Tdc corresponding to the exhaust pressure Pd of the compressor 520 and the evaporation temperature Tl is less than or equal to 5° C. The eighth preset condition includes: the exhaust pressure Pd of the compressor 520 is less than 2.7 MPa.

[0217] In some embodiments, the air conditioning system 1 includes an eighth temperature sensor, a ninth temperature sensor, a tenth temperature sensor, and a fourth pressure sensor.

[0218] The eighth temperature sensor is configured to detect the evaporation temperature T1, the ninth temperature sensor is configured to detect the outlet temperature Te of the outdoor heat exchanger 510, and the tenth temperature sensor is configured to detect the exhaust temperature Td of the compressor 520. The fourth pressure sensor is configured to detect the exhaust pressure Pd of the compressor 520.

[0219] In this way, when the air-conditioning system 1 operates in cooling mode, based on the above-mentioned refrigeration cycle, the first shut-off valve can be switched to an open state to connect the third branch 730, and the second shut-off valve can be switched to an open state to connect the fourth branch 740, so that part of the refrigerant can be guided to flow through the corresponding indoor expansion valve and stored in the corresponding indoor heat exchanger.

[0220] In some embodiments, as shown in FIG16 , the first indoor unit 610 is in the ON state (ON) and the second indoor unit 22 is in the OFF state (OFF). When the air conditioning system 1 is in a stable state, the third sub-blocking valve 721 and the first sub-blocking valve 711 are open, and the first indoor expansion valve 612 operates to ensure normal operation of the first indoor unit 610. The fourth sub-blocking valve 722 and the second sub-blocking valve 712 are closed.

[0221] When the load of the air-conditioning system 1 changes, that is, when it is in an unstable state, the fourth heat exchanger 621 can be used to store the refrigerant.

[0222] As shown in Figure 17, when the actual exhaust superheat of the compressor 520 is lower than the target value, the fourth heat exchanger 621 can be used to store refrigerant. In this case, the fourth sub-shutoff valve 722 and the second sub-shutoff valve 712 are switched to the open state to connect the fourth sub-branch 742 and the second sub-branch 732, and the second indoor expansion valve 622 starts to operate.

[0223] For example, the second indoor expansion valve 622 operates in a gradually opening state. When the second indoor expansion valve 622 operates in a gradually opening state, the initial valve opening of the second indoor expansion valve 622 is 5%, and the valve opening increases by 1% every 60 seconds.

[0224] When the air-conditioning system 1 returns to a stable state and lasts for a second preset time (such as any value between 5 minutes and 10 minutes), the fourth sub-shutoff valve 722 and the second sub-shutoff valve 712 are switched to a closed state, and part of the refrigerant in the air-conditioning system 1 will be stored in the fourth heat exchanger 621.

[0225] For example, when the fourth sub-blocking valve 722 and the second sub-blocking valve 712 are switched to the closed state, the second indoor expansion valve 622 is at a preset opening to prevent liquid sealing, for example, the preset opening is 2%.

[0226] In some embodiments, the third sub-block valve 721 , the fourth sub-block valve 722 , the first sub-block valve 711 , and the second sub-block valve 712 may be solenoid valves, electric ball valves, or electronic expansion valves.

[0227] In some embodiments, when the air-conditioning system 1 operates in heating mode, based on the above-mentioned heating cycle, the first shut-off valve can be switched to an open state to connect the third branch 730, and the second shut-off valve can be switched to an open state to connect the fourth branch 740, so that part of the refrigerant can be guided to flow through the corresponding indoor expansion valve and stored in the corresponding indoor heat exchanger.

[0228] As shown in FIG. 18 and FIG. 19 , the first indoor unit 610 is in the ON state (ON), and the second indoor unit 22 is in the OFF state (OFF).

[0229] When the air conditioning system 1 is in a stable state, as shown in FIG18 , the third sub-blocking valve 721 and the first sub-blocking valve 711 are in an open state, and the first indoor expansion valve 612 is in operation to ensure the normal operation of the first indoor unit 610. The fourth sub-blocking valve 722 and the second sub-blocking valve 712 are in a closed state.

[0230] When the load of the air-conditioning system 1 changes, that is, when it is in an unstable state, the fourth heat exchanger 621 can be used to store the refrigerant.

[0231] 19 , the fourth sub-blocking valve 722 and the second sub-blocking valve 712 are switched to an open state, thereby connecting the fourth sub-branch 742 and the second sub-branch 732, and the second indoor expansion valve 622 begins to operate. For example, the second indoor expansion valve 622 operates in a gradually opening state.

[0232] When the air-conditioning system 1 returns to a stable state and lasts for a second preset time (such as any value between 5 minutes and 10 minutes), the fourth sub-shutoff valve 722 and the second sub-shutoff valve 712 are switched to a closed state, and part of the refrigerant in the air-conditioning system 1 will be stored in the fourth heat exchanger 621.

[0233] For example, when the fourth sub-blocking valve 722 and the second sub-blocking valve 712 are switched to the closed state, the second indoor expansion valve 622 is at a preset opening to prevent liquid sealing, for example, the preset opening is 2%.

[0234] In some embodiments, when air conditioning system 1 is operating in cooling mode and is in an unstable state, the amount of refrigerant can be adjusted by releasing the refrigerant stored in the indoor heat exchanger. For example, the second shutoff valve is switched to an open state to connect the fourth branch 740, thereby directing the refrigerant in the corresponding indoor heat exchanger to flow out and participate in the refrigeration cycle.

[0235] 20 and 21 , the first indoor unit 610 is in an ON state, and the second indoor unit 620 is in an OFF state. For example, the fourth heat exchanger 621 of the second indoor unit 620 is pre-stored with refrigerant.

[0236] As shown in FIG20 , when the air conditioning system 1 is in a stable state, the third sub-blocking valve 721 and the first sub-blocking valve 711 are open, and the first indoor expansion valve 612 is operating to ensure normal operation of the first indoor unit 610. The fourth sub-blocking valve 722 and the second sub-blocking valve 712 are closed.

[0237] When the load of air conditioning system 1 changes, that is, when it is in an unstable state, the refrigerant pre-stored in fourth heat exchanger 621 can be released, allowing the pre-stored refrigerant to participate in the refrigeration cycle. As shown in Figure 21, the fourth sub-blocking valve 722 is switched to the open state, thereby connecting the fourth sub-branch 742 and the second indoor expansion valve 622 to begin operation. For example, the second indoor expansion valve 622 operates in a gradually opening state.

[0238] When the air conditioning system 1 returns to a stable state, the fourth sub-blocking valve 722 switches to a closed state, and the refrigerant stored in the fourth heat exchanger 621 enters the refrigeration cycle. For example, when the fourth sub-blocking valve 722 switches to a closed state, the second indoor expansion valve 622 is at a preset opening to prevent liquid sealing.

[0239] In some embodiments, when the air-conditioning system 1 operates in heating mode, on the basis of the above-mentioned heating cycle, the first shut-off valve can be switched to an open state to connect the third branch 730, and the second shut-off valve can be switched to an open state to connect the fourth branch 740, so that the refrigerant stored in the corresponding indoor heat exchanger can be guided to flow out and participate in the refrigeration cycle.

[0240] As shown in FIG. 22 and FIG. 23 , the first indoor unit 610 is in the ON state (ON), and the second indoor unit 22 is in the OFF state (OFF).

[0241] When the air conditioning system 1 is in a stable state, as shown in FIG22 , the third sub-blocking valve 721 and the first sub-blocking valve 711 are in an open state, and the first indoor expansion valve 612 operates normally to ensure the normal operation of the first indoor unit 610. The fourth sub-blocking valve 722 and the second sub-blocking valve 712 are in a closed state.

[0242] When the load of the air-conditioning system 1 changes, that is, when it is in an unstable state, the refrigerant pre-stored in the fourth heat exchanger 621 may be released so that the pre-stored refrigerant participates in the refrigeration cycle.

[0243] 23 , the fourth sub-blocking valve 722 and the second sub-blocking valve 712 are switched to an open state, thereby connecting the fourth sub-branch 742 and the second sub-branch 732, and the second indoor expansion valve 622 begins to operate. For example, the second indoor expansion valve 622 operates in a gradually opening state.

[0244] When the air conditioning system 1 returns to a stable state, the fourth sub-blocking valve 722 and the second sub-blocking valve 712 are switched to a closed state, allowing the refrigerant stored in the fourth heat exchanger 621 to participate in the refrigeration cycle. For example, when the fourth sub-blocking valve 722 and the second sub-blocking valve 712 are switched to a closed state, the second indoor expansion valve 622 is at a preset opening to prevent liquid sealing.

[0245] Those skilled in the art will understand that the scope of the present invention is not limited to the above specific embodiments, and that certain elements of the embodiments may be modified and replaced without departing from the spirit of the present invention. The scope of the present invention is limited by the appended claims.

Claims

1. An air conditioning system, comprising: compressor; a first heat exchanger connected to the compressor and configured to perform heat exchange between the refrigerant discharged from the compressor and outdoor air; a second heat exchanger connected to the compressor and configured to perform heat exchange between the refrigerant discharged from the compressor and water; At least one indoor unit; Any one of the at least one indoor unit comprises an indoor heat exchanger; the indoor heat exchanger is connected to the first heat exchanger through a first pipeline and a third pipeline, and is connected to the second heat exchanger through the first pipeline and a fourth pipeline; a detection unit connected to the at least one indoor unit and configured to detect the refrigerant concentration in the space where the indoor heat exchanger is located; and a control unit connected to the detection unit and configured to: determining whether the refrigerant concentration detected by the detection unit is higher than a preset threshold; and When the refrigerant concentration is higher than the preset threshold, determining that the refrigerant has leaked, and controlling the air conditioning system to execute a refrigerant recovery mode; Wherein, the air conditioning system further comprises: A first throttling device, disposed on the third pipeline; and A second throttling device is arranged on the fourth pipeline; The control unit is further configured to: When the air conditioning system executes the refrigerant recovery mode, based on the difference between the temperatures of the refrigerants in the third pipeline and the fourth pipeline, correcting the opening of the first throttling device; Based on the difference between the temperature of the refrigerant in the fourth pipeline and the temperature of the refrigerant in the third pipeline, correcting the opening degree of the second throttling device; and The opening degree changes of the first throttling device and the second throttling device in the refrigerant recovery mode are controlled not to exceed a preset range.

2. The air conditioning system according to claim 1, wherein: The control unit is further configured to: When the air conditioning system executes the refrigerant recovery mode, an air side adjustment proportional coefficient is calculated based on the temperature difference of the refrigerant in the third pipeline and the fourth pipeline; wherein the air side adjustment proportional coefficient is a ratio of a first set constant to the temperature difference between the refrigerant in the third pipeline and the fourth pipeline; and The product of the air side regulation proportional coefficient and the opening of the first throttling device in the current regulation cycle is used as the opening of the first throttling device in the next regulation cycle; wherein the opening of the first throttling device in the next regulation cycle is less than or equal to the opening of the first throttling device in the current regulation cycle.

3. The air conditioning system according to claim 1, wherein: The control unit is further configured to: When the air conditioning system executes the refrigerant recovery mode, a water side adjustment proportional coefficient is calculated based on a temperature difference between the refrigerant in the fourth pipeline and the third pipeline; wherein the water side adjustment proportional coefficient is a ratio of a second set constant to a temperature difference between the refrigerant in the fourth pipeline and the third pipeline; and The product of the water side regulation proportional coefficient and the opening of the second throttling device in the current regulation cycle is used as the opening of the second throttling device in the next regulation cycle; wherein the opening of the second throttling device in the next regulation cycle is less than or equal to the opening of the second throttling device in the current regulation cycle.

4. The air conditioning system according to any one of claims 1 to 3, further comprising: a second pipeline, the indoor heat exchanger is connected to the compressor through the second pipeline; A second cut-off valve is arranged on the second pipeline; as well as A first cut-off valve, disposed on the first pipeline; The at least one indoor unit includes an indoor heat exchanger and a plurality of indoor throttling devices; the plurality of indoor throttling devices correspond to the plurality of indoor heat exchangers; The detection unit is further configured to: when the refrigerant concentration in the space where any one of the plurality of indoor heat exchangers is located reaches the preset threshold, determine that there is refrigerant leakage in the space where any one of the plurality of indoor heat exchangers is located; The control unit is further configured to execute the refrigerant recovery mode when the detection unit determines that a refrigerant leak occurs in the space where any one of the indoor heat exchangers is located.

5. The air conditioning system according to claim 4, wherein: The control unit is further configured to: When the air conditioning system executes the refrigerant recovery mode, any one of the indoor heat exchangers is configured as an evaporator; Controlling the first shutoff valve to close so as to cut off the fluid passage in the first pipeline; Controlling the first throttling device to open to a first preset opening; Controlling the second throttling device to open to a second preset opening; Controlling the plurality of indoor throttling devices to open to a maximum opening; Based on the first preset opening, the opening of the first throttling device is corrected based on the difference between the temperatures of the refrigerants in the third pipeline and the fourth pipeline; as well as The opening degree of the second throttling device is corrected based on the difference between the temperatures of the refrigerants in the fourth pipeline and the third pipeline on the basis of the second preset opening degree.

6. The air conditioning system according to claim 5, wherein: The first preset opening is the maximum opening to which the first throttling device can be opened, and the second preset opening is the maximum opening to which the second throttling device can be opened.

7. The air conditioning system according to claim 5, wherein: The first preset opening is the operating opening of the first throttling device, and the second preset opening is the operating opening of the second throttling device.

8. The air conditioning system according to claim 7, wherein: The control unit is further configured to: determining that the second heat exchanger is configured as a condenser; When the first heat exchanger is configured as a condenser, the operating opening of the second throttling device is generated according to the subcooling at the outlet of the second heat exchanger, and the operating opening of the first throttling device is generated according to the subcooling at the outlet of the first heat exchanger.

9. The air conditioning system according to claim 7, wherein: The control unit is further configured to: determining that the second heat exchanger is configured as a condenser; When the first heat exchanger is configured as an evaporator, the operating opening of the second throttling device is generated according to the subcooling at the outlet of the second heat exchanger, and the operating opening of the first throttling device is generated according to the exhaust gas superheat of the compressor.

10. The air conditioning system according to any one of claims 5 to 9, wherein: Any of the indoor units further comprises an indoor fan, wherein the indoor fan is configured to output airflow to the indoor heat exchanger, so that the airflow exchanges heat with the refrigerant in the third heat exchanger, and outputs the heat-exchanged airflow to the indoor room; The air conditioning system further comprises an outdoor fan, wherein the outdoor fan is configured to provide an airflow to the first heat exchanger so that the airflow exchanges heat with the refrigerant in the first heat exchanger, causing the refrigerant to undergo a phase change; The control unit is also configured to: when the multiple indoor throttling devices are opened to the maximum opening, control the speed of the indoor fan to increase to a high wind gear, and control the speed of the outdoor fan to increase to a high wind gear to increase the refrigerant recovery speed.

11. The air conditioning system according to any one of claims 5 to 10, wherein: The control unit is further configured to: After correcting the opening of the second throttling device based on the difference between the temperatures of the refrigerants in the fourth pipeline and the third pipeline, when the pressure on the suction side of the compressor is less than or equal to a preset pressure, the air-conditioning system is controlled to terminate the refrigerant recovery mode.

12. The air conditioning system according to claim 11, wherein: The controlling the air conditioning system to terminate the refrigerant recovery mode comprises: Controlling the second shutoff valve to close so as to cut off the fluid passage in the second pipeline; controlling the compressor to stop running; and The indoor throttling device is controlled to be closed to a minimum opening.

13. The air conditioning system according to any one of claims 1 to 12, wherein: The control unit is further configured to: After controlling the opening degree changes of the first throttling device and the second throttling device in the refrigerant recovery mode not to exceed a preset range, controlling the air conditioning system to execute an emergency control mode; Wherein, the emergency control mode includes: configuring the second heat exchanger to be a condenser; Controlling the second throttling device to open to a maximum opening; and The emergency operating opening of the first throttling device is determined according to the exhaust gas superheat of the compressor.

14. The air conditioning system according to any one of claims 1 to 13, further comprising an outdoor unit, the outdoor unit comprising an outdoor heat exchanger; The at least one indoor unit includes a plurality of indoor units, and the plurality of indoor units are connected to the outdoor unit through the first pipeline and the second pipeline; in, The air conditioning system further comprises: at least one third branch, one end of the indoor heat exchanger is connected to the first pipeline through the third branch; at least one fourth branch, corresponding to the at least one fourth branch; the other end of the indoor heat exchanger is connected to the second pipeline through the fourth branch; at least one first shutoff valve, any one of the at least one first shutoff valve being disposed on any one of the at least one third branch; the first shutoff valve being configured to: switch a state to adjust the amount of refrigerant in the corresponding indoor heat exchanger; and At least one second shut-off valve, any one of the at least one second shut-off valve is arranged on any one of the at least one fourth branch; the second shut-off valve is configured to: switch state to adjust the amount of refrigerant in the corresponding indoor heat exchanger.

15. The air conditioning system according to claim 14, wherein: Any one of the third branches corresponds to any two indoor units among the multiple indoor units; Any one of the first shutoff valves is configured to: switch states to adjust the amount of refrigerant in the indoor heat exchangers of any two indoor units; Any one of the second shutoff valves is configured to switch states to adjust the amount of refrigerant in the indoor heat exchangers of any two indoor units.

16. The air conditioning system according to claim 14, wherein: The number of the first cutoff valves is less than or equal to the number of the indoor units, and the number of the second cutoff valves is less than or equal to the number of the indoor units.

17. The air conditioning system according to any one of claims 14 to 16, wherein: Any of the first cut-off valves is further configured to be switched to an open state to conduct any of the third branches; Any of the second cut-off valves is further configured to be switched to an open state to conduct any of the fourth branches; When the third branch and the corresponding fourth branch are both connected, part of the refrigerant in the air-conditioning system passes through the corresponding indoor expansion valve and is stored in the corresponding indoor heat exchanger.

18. The air conditioning system according to any one of claims 14 to 16, wherein: Any of the second shut-off valves is also configured to: when the air-conditioning system operates in a cooling mode, switch to an open state to open any of the fourth branches and guide the refrigerant in the corresponding indoor heat exchanger to flow out and participate in the refrigeration cycle.

19. The air conditioning system according to any one of claims 14 to 16, wherein: Any of the second cut-off valves is further configured to: when the air-conditioning system operates in a heating mode, switch to an open state to conduct any of the fourth branches; Any of the first cut-off valves is further configured to: when the air-conditioning system operates in the heating mode, switch to an open state to conduct any of the third branches; Among them, when the air-conditioning system runs the heating mode and the fourth branch and the corresponding third branch are both connected, the refrigerant in the indoor heat exchanger corresponding to the fourth branch is guided to flow out and participate in the heating cycle.

20. The air conditioning system according to any one of claims 14 to 19, wherein: Either the first cutoff valve or the second cutoff valve is a solenoid valve, an electric ball valve, or an electronic expansion valve.

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