Multi-split air conditioning system

Abstract

The present application discloses a multi-split air conditioning system (100), comprising an air conditioning system (110), a hot water system (120), a regulation unit (130), and a controller (71) connected to one another. The controller (71) controls, in response to a first control instruction, the multi-split air conditioning system (100) to operate in a defrosting mode. In the defrosting mode, the controller (71) controls the state of the regulation unit (130) so that a water tank heat exchanger (21) in the hot water system (120) is used as an evaporator, and refrigerant in a water tank branch (22) is heated by water in a water tank (20). The heated refrigerant flows through a compressor (1), and then exchanges heat with an outdoor heat exchanger (2), so as to defrost the outdoor heat exchanger (2), thereby transferring heat from the water tank (20) to the outdoor heat exchanger (2). The defrosting speed is effectively accelerated, the impact on the indoor temperature is significantly reduced, and the efficient operation and stability of the air conditioning system (110) in a low temperature environment are ensured.

Description

Multi-split air conditioning system

[0001] This application claims priority to Chinese patent application No. 202510095951.X, filed on January 21, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of home appliance technology, and in particular to a multi-split air conditioning system. Background Technology

[0003] Multi-split air conditioning systems are a type of central air conditioning system for users, commonly known as "one-to-many," which refers to one outdoor unit connected to two or more indoor units.

[0004] Defrosting during heating operation of multi-split air conditioning systems has always been a significant factor affecting their performance and user experience. When the external ambient temperature is low, the outdoor heat exchanger is prone to frost buildup, reducing heat exchange efficiency, leading to a decline in system performance, and even equipment shutdown. However, existing defrosting methods suffer from problems such as long defrosting times, high energy consumption, and a significant reduction in user comfort. Summary of the Invention

[0005] This application proposes a multi-split air conditioning system that transfers heat from the water tank to the outdoor heat exchanger. This not only effectively speeds up the defrosting process but also significantly reduces the impact on indoor temperature, ensuring the efficient operation and stability of the air conditioning system in low-temperature environments. This improves overall operating performance and avoids the negative impact of temperature fluctuations during the defrosting process on user comfort.

[0006] According to one aspect of this application, a multi-split air conditioning system is proposed, comprising: an air conditioning system including a compressor, an outdoor heat exchanger, an outdoor electronic expansion valve, an expansion valve assembly, an indoor heat exchanger assembly, and a first four-way valve; the compressor, the outdoor heat exchanger, the outdoor electronic expansion valve, the expansion valve assembly, the indoor heat exchanger assembly, and the first four-way valve forming a refrigerant circulation loop to circulate the refrigerant within the loop; and a hot water system connected to the air conditioning system, comprising: a water tank; a water tank heat exchanger disposed on the water tank; and a water tank branch circuit, the water tank heat exchanger being connected to the refrigerant circulation loop via the water tank branch circuit; when the water tank heat exchanger is used as an evaporator, the refrigerant in the water tank branch circuit can be heated by the water in the water tank, and the heated refrigerant flows through the compressor and exchanges heat with the outdoor heat exchanger to defrost the outdoor heat exchanger; and adjusting... The system comprises a regulating unit, which is connected to the refrigerant circulation loop and the water tank branch respectively. The regulating unit is used to regulate the on / off state between the refrigerant circulation loop and the water tank branch, as well as the on / off state between the outdoor heat exchanger and the indoor heat exchanger group in the refrigerant circulation loop. A controller is connected to both the air conditioning system and the regulating unit. The controller is configured to: respond to a first control command, control the multi-split air conditioning system to operate in defrost mode, and in defrost mode, control the state of the regulating unit, thereby controlling the disconnection between the refrigerant circulation loop and the water tank branch, and controlling the disconnection between the outdoor heat exchanger and the indoor heat exchanger group in the refrigerant circulation loop, so that the water tank heat exchanger is used as an evaporator, heating the refrigerant in the water tank branch with water in the water tank. The heated refrigerant flows through the compressor and exchanges heat with the outdoor heat exchanger to defrost the outdoor heat exchanger.

[0007] The above technical solution has the following advantages or beneficial effects: The multi-split air conditioning system provided according to the embodiments of this application includes an interconnected air conditioning system, a hot water system, a regulating unit, and a controller. The water tank heat exchanger in the hot water system can be used as an evaporator. The controller responds to a first control command and controls the multi-split air conditioning system to operate in defrost mode. In defrost mode, the controller controls the state of the regulating unit, thereby controlling the disconnection between the refrigerant circulation loop and the water tank branch, and controlling the disconnection between the outdoor heat exchanger and the indoor heat exchanger group in the refrigerant circulation loop, so that the water tank heat exchanger in the hot water system can be used as an evaporator. The water in the water tank heats the refrigerant in the water tank branch. The heated refrigerant flows through the compressor and exchanges heat with the outdoor heat exchanger to defrost the outdoor heat exchanger. This transfers the heat in the water tank to the outdoor heat exchanger, which not only effectively speeds up the defrosting process but also significantly reduces the impact on the indoor temperature, ensuring the efficient operation and stability of the air conditioning system in low-temperature environments, thereby improving the overall operating performance and avoiding the negative impact of temperature fluctuations during the defrosting process on user comfort.

[0008] Additional aspects and features of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0009] The above and / or additional aspects and features of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0010] Figure 1 is a structural schematic diagram of a multi-split air conditioning system according to some embodiments of this application;

[0011] Figure 2 is a schematic diagram of the specific structure of a multi-split air conditioning system according to some embodiments of this application;

[0012] Figure 3 is a schematic diagram of the specific structure of a multi-split air conditioning system according to some embodiments of this application;

[0013] Figure 4 is a schematic diagram of a hot water system according to some embodiments of this application;

[0014] Figure 5 is a schematic diagram of the hardware structure of a controller according to some embodiments of this application;

[0015] Figure 6 is a schematic diagram of the structure of an air conditioning system according to some embodiments of this application;

[0016] Figure 7 is a schematic diagram of the structure of an air conditioning system refrigeration system according to some embodiments of this application;

[0017] Figure 8 is a schematic diagram of the structure of an adjustment unit according to some embodiments of this application;

[0018] Figure 9 is a schematic diagram of the refrigerant flow direction in a refrigeration mode according to some embodiments of this application;

[0019] Figure 10 is a schematic diagram of the refrigerant flow direction in a refrigeration mode according to some other embodiments of this application;

[0020] Figure 11 is a schematic diagram of the refrigerant flow direction in a heating mode according to some embodiments of this application;

[0021] Figure 12 is a schematic diagram of the refrigerant flow direction in a heating mode according to some other embodiments of this application;

[0022] Figure 13 is a schematic diagram of the refrigerant flow in a water tank individual heating mode according to some embodiments of this application;

[0023] Figure 14 is a schematic diagram of the refrigerant flow in a separate heating mode for the water tank according to some other embodiments of this application;

[0024] Figure 15 is a schematic diagram of the refrigerant flow in a first refrigeration and water tank heating mode according to some embodiments of this application;

[0025] Figure 16 is a schematic diagram of the refrigerant flow in a first refrigeration and water tank heating mode according to some other embodiments of this application;

[0026] Figure 17 is a schematic diagram of the refrigerant flow in a second refrigeration and water tank heating mode according to some embodiments of this application;

[0027] Figure 18 is a schematic diagram of the refrigerant flow in a second refrigeration and water tank heating mode according to some other embodiments of this application;

[0028] Figure 19 is a schematic diagram of the refrigerant flow in the heating and water tank heating modes according to some embodiments of this application;

[0029] Figure 20 is a schematic diagram of the refrigerant flow in the heating and water tank heating modes according to some other embodiments of this application;

[0030] Figure 21 is a schematic diagram of the refrigerant flow direction in a defrosting mode according to some embodiments of this application;

[0031] Figure 22 is a schematic diagram of the refrigerant flow direction in a defrosting mode according to some other embodiments of this application;

[0032] Figure 23 is a first installation schematic diagram of a subcooling device according to some embodiments of this application;

[0033] Figure 24 is a second installation schematic diagram of the subcooling device according to some embodiments of this application;

[0034] Figure 25 is a first installation schematic diagram of a subcooling device according to some other embodiments of this application;

[0035] Figure 26 is a second installation schematic diagram of the subcooling device according to some other embodiments of this application;

[0036] Figure 27 is a schematic diagram of the structure of a hot water system according to some embodiments of this application. Embodiments of the present invention

[0037] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0038] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0039] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0040] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0041] Figure 1 is a structural schematic diagram of a multi-split air conditioning system according to some embodiments of the present application. According to one embodiment of the present application, as shown in Figure 1, a multi-split air conditioning system 100 is provided, which includes an air conditioning system 110, a hot water system 120, a regulating unit 130, and a controller 71.

[0042] In some embodiments, as shown in FIG2, the air conditioning system 110 includes: a compressor 1, an outdoor heat exchanger 2, an outdoor electronic expansion valve 3, an expansion valve assembly, an indoor heat exchanger assembly, a shut-off valve assembly, and a first four-way valve 4. The compressor 1, outdoor heat exchanger 2, outdoor electronic expansion valve 3, expansion valve assembly, indoor heat exchanger assembly, shut-off valve assembly, and first four-way valve 4 form a refrigerant circulation loop, in which the refrigerant circulates. Refrigerant, commonly known as refrigerant or refrigerant fluid, is the working medium used in refrigeration and air conditioning systems to transfer heat and achieve cooling or heating. Through its own phase change process, it circulates and absorbs and releases heat in the system, thereby achieving the purpose of temperature regulation.

[0043] As shown in Figures 2 and 3, in some embodiments, the first port of the first four-way valve 4 is connected to the outlet of the compressor 1, the second port of the first four-way valve 4 is connected to the outdoor heat exchanger 2, the third port of the first four-way valve 4 is connected to the indoor heat exchanger assembly, and the fourth port of the first four-way valve 4 is connected to the inlet of the compressor 1. The expansion valve assembly includes multiple first electronic expansion valves 6 connected in parallel, one end of each first electronic expansion valve 6 is connected to one end of the outdoor electronic expansion valve 3, and the other end of each first electronic expansion valve 6 is connected to one end of the corresponding indoor heat exchanger 5.

[0044] In some embodiments, the first port of the first four-way valve 4 (i.e., the upper port of the first four-way valve 4 in Figures 2 and 3) is connected to the outlet of the compressor 1, the second port of the first four-way valve 4 (i.e., the right port of the first four-way valve 4 in Figures 2 and 3) is connected to the outdoor heat exchanger 2, the third port of the first four-way valve 4 (i.e., the left port of the first four-way valve 4 in Figures 2 and 3) is connected to the indoor heat exchanger assembly, and the fourth port of the first four-way valve 4 (i.e., the lower port of the first four-way valve 4 in Figures 2 and 3) is connected to the inlet of the compressor 1.

[0045] In some embodiments, the indoor heat exchanger assembly includes a plurality of indoor heat exchangers 5 connected in parallel. For example, the indoor heat exchanger assembly in FIG2 includes three indoor heat exchangers 5 connected in parallel. The expansion valve assembly includes a plurality of first electronic expansion valves 6 connected in parallel. For example, the expansion valve assembly in FIG2 includes three first electronic expansion valves 6 connected in parallel. The two ends of each first electronic expansion valve 6 are respectively connected to the outdoor electronic expansion valve 3 and the corresponding indoor heat exchanger 5.

[0046] It should be noted that the quantities shown in Figure 2 are merely illustrative, and the quantities of the first electronic expansion valve 6 and the indoor heat exchanger 5 can be other numbers.

[0047] The multi-split air conditioning system 100 provided in this application embodiment can control the on / off state of the inflow of the indoor heat exchanger group and adjust the refrigerant flow rate into or out of the indoor heat exchanger group through the expansion valve group, thereby facilitating the control of the multi-split air conditioning system 100.

[0048] In some embodiments, the number of indoor heat exchanger groups corresponds to the number of expansion valve groups, and the number of indoor heat exchanger groups corresponds to the number of shut-off valve groups, that is, the number of indoor heat exchangers 5, first electronic expansion valves 6, first shut-off valves 7 and second shut-off valves 8 are the same.

[0049] In some embodiments, the air conditioning system 110 is a multi-split air conditioning system, commonly known as a "multi-split air conditioner" or "multi-split air conditioner". It is a common type of central air conditioning system, and its core feature is that one outdoor unit is connected to multiple indoor units.

[0050] In some embodiments, as shown in Figures 2 and 3, the hot water system 120 is connected to the air conditioning system 110. As shown in Figure 4, the hot water system 120 includes: a water tank 20, a water tank heat exchanger 21, and a water tank branch line 22. The water tank heat exchanger 21 is disposed on the water tank 20, for example, wound around the water tank 20; the water tank heat exchanger 21 is connected to the refrigerant circulation loop of the air conditioning system 110 through the water tank branch line 22.

[0051] In some embodiments, the water tank branch 22 includes a first water tank branch 221 and a second water tank branch 222; wherein, one end of the first water tank branch 221 is connected to the outlet of the compressor 1, and the other end of the first water tank branch 221 is connected to one end of the water tank heat exchanger 21, and one end of the second water tank branch 222 is connected to the other end of the water tank heat exchanger 21, and the other end of the second water tank branch 222 is connected to one end of the expansion valve assembly and one end of the expansion valve assembly 3; when the water tank heat exchanger 21 is used as an evaporator, the refrigerant in the water tank branch can be heated by the water in the water tank 20, and the heated refrigerant flows through the compressor 1 and exchanges heat with the outdoor heat exchanger 2 to defrost the outdoor heat exchanger 2.

[0052] In some embodiments, the regulating unit 130 is connected to the refrigerant circulation loop and the water tank branch 22 respectively. By controlling the state of the regulating unit 130, the on / off state between the refrigerant circulation loop and the water tank branch 22, as well as the on / off state between the outdoor heat exchanger 2 and the indoor heat exchanger group in the refrigerant circulation loop, can be controlled.

[0053] In some embodiments, the regulating unit 130 includes, for example, a plurality of solenoid valves.

[0054] In some embodiments, the controller 71, connected to the regulating unit 130, is configured to: in response to a first control command, control the multi-split air conditioning system 100 to operate in defrost mode, and in defrost mode, control the state of each component in the regulating unit 130, thereby controlling the disconnection between the refrigerant circulation loop and the water tank branch 22, as well as the disconnection between the outdoor heat exchanger 2 and the indoor heat exchanger group in the refrigerant circulation loop, so that the water tank heat exchanger 21 is used as an evaporator, and the refrigerant in the water tank branch 22 is heated by the water in the water tank 20. The heated refrigerant flows through the compressor 1 and exchanges heat with the outdoor heat exchanger 2 to defrost the outdoor heat exchanger 2.

[0055] In some embodiments, when the water tank heat exchanger 21 is used as a condenser, the refrigerant in the refrigerant circulation loop can flow through the water tank branch 22 through the water tank heat exchanger 21 for heat exchange, so that the water tank heat exchanger 21 heats the water in the water tank 20.

[0056] In some embodiments, the operator can send a first control command through the terminal to cause the controller 71 to control the multi-split air conditioning system 100 to operate in defrost mode. In defrost mode, the controller 71 controls the state of each component in the regulating unit 130, thereby controlling the disconnection between the refrigerant circulation loop and the water tank branch 22, as well as the disconnection between the outdoor heat exchanger 2 and the indoor heat exchanger group in the refrigerant circulation loop, so that the water tank heat exchanger 21 is used as an evaporator. The water in the water tank 20 heats the refrigerant in the water tank branch 22. The heated refrigerant flows through the compressor 1 and exchanges heat with the outdoor heat exchanger 2 to defrost the outdoor heat exchanger 2. This transfers the heat in the water tank 20 to the outdoor heat exchanger 2, which not only effectively speeds up the defrosting process but also significantly reduces the impact on the indoor temperature, ensuring the efficient operation and stability of the air conditioning system 110 in low-temperature environments. This improves the overall operating performance and avoids the negative impact of temperature fluctuations during the defrosting process on user comfort.

[0057] The multi-split air conditioning system 100 provided in this application embodiment includes an air conditioning system 110, a hot water system 120, a regulating unit 130, and a controller 71 connected to each other. The water tank heat exchanger 21 in the hot water system 120 can be used as an evaporator. The controller 71 responds to a first control command and controls the multi-split air conditioning system 100 to operate in defrost mode. In defrost mode, the controller 71 controls the state of each component in the regulating unit 130, thereby controlling the disconnection between the refrigerant circulation loop and the water tank branch 22, and controlling the disconnection between the outdoor heat exchanger 2 and the indoor heat exchanger group in the refrigerant circulation loop. This allows the water tank heat exchanger 21 in the hot water system 120 to be used as an evaporator. The water in the water tank 20 heats the refrigerant in the water tank branch 22. The heated refrigerant flows through the compressor 1 and exchanges heat with the outdoor heat exchanger 2 to defrost the outdoor heat exchanger 2. This transfers the heat from the water tank 20 to the outdoor heat exchanger 2, which not only effectively speeds up the defrosting process but also significantly reduces the impact on the indoor temperature. This ensures the efficient operation and stability of the air conditioning system 110 in low-temperature environments, thereby improving the overall operating performance and avoiding the negative impact of temperature fluctuations during the defrosting process on user comfort.

[0058] In some embodiments, controller 71 refers to a device that can generate operation control signals based on instruction opcodes and timing signals to instruct electrical equipment 10 to execute a first control instruction. For example, in response to a power-on or power-off command issued by a user, controller 71 can perform an operation related to the object selected by the power-on or power-off command.

[0059] Figure 5 is a schematic diagram of the hardware structure of a controller according to a specific embodiment of the present invention. As shown in Figure 5, in some embodiments, the controller 71 includes a processor 83, and in some embodiments, the controller 71 further includes a memory 82 and a communication interface 84 connected to the processor 83. The processor 83, the memory 82, and the communication interface 84 are connected via a bus 81.

[0060] Processor 83 can be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. Processor 83 can also be any other device with processing capabilities, such as a circuit, device, or software module. Processor 83 can also include multiple CPUs, and processor 83 can be a single-core processor or a multi-core processor. Here, processor 83 can refer to one or more devices, circuits, or processing cores used for processing data (e.g., computer program instructions).

[0061] The memory 82 can be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions. It can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer. This application embodiment does not impose any limitations on this. The memory 82 can exist independently or be integrated with the processor 83. The memory 82 may contain computer program code. The processor 83 is used to execute the computer program code stored in the memory 82, thereby implementing the control method for the electrical equipment provided in this application embodiment.

[0062] The communication interface 84 can be a communication interface for other devices or communication networks (such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.), or it can be a module, circuit, transceiver, or any device capable of communication.

[0063] Bus 81 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. Bus 81 can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in Figure 5, but this does not mean that there is only one bus 81 or only one type of bus 81.

[0064] Figure 6 is a structural schematic diagram of a multi-split air conditioning system according to some embodiments of this application. As shown in Figure 6, the multi-split air conditioning system 100 includes multiple indoor units 101 and one outdoor unit 102. The indoor units 101 and the outdoor unit 102 can be configured as an integrated unit or a split unit. The indoor units 101 can be configured as wall-mounted, ceiling-mounted, ducted, or other types, and the indoor units 101 are installed on the top or ceiling of the room.

[0065] Referring to Figure 6, taking the wall-mounted indoor unit 101 as an example, the wall-mounted indoor unit 101 is usually installed on the indoor wall or other locations.

[0066] Taking the indoor unit 101 and the outdoor unit 102 as a split unit as an example, the multi-split air conditioning system 100 includes multiple indoor units 101 and one outdoor unit 102. The outdoor unit 102 is usually installed outdoors and is used for heat exchange in the indoor environment.

[0067] Furthermore, the multi-split air conditioning system 100 includes a controller 71 to control the operation of various components within the internal air conditioning system 110, enabling each component of the air conditioning system 110 to perform its predetermined functions. The multi-split air conditioning system 100 also includes a control device 200, as shown in Figure 6. For example, the control device 200 can be a remote control, which has the function of communicating with the controller 71, for example, using infrared or other communication methods. The remote control is used by the user to control various aspects of the air conditioning system 110, enabling interaction between the user and the air conditioning system 110.

[0068] In some embodiments, the indoor unit 101 of the multi-split air conditioning system 100 is usually installed at the top or upper part of the room. Generally, the installation height of the indoor unit 101 is higher than the user's activity area. The indoor unit 101 includes a return air vent and an air outlet that communicate with the room. Indoor air passes through the return air vent into the indoor unit 101 and flows back into the room through the air outlet.

[0069] Figure 7 is a schematic diagram of an air conditioning system according to some embodiments of this application. The air conditioning system 110 is used to exchange heat with indoor air to meet cooling or heating needs.

[0070] In some embodiments, as shown in FIG7, the air conditioning system 110 includes a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger. In this embodiment, the air conditioning system 110 performs a cooling cycle or a heating cycle by using the compressor, indoor heat exchanger, expansion valve, and outdoor heat exchanger. D represents the compressor discharge port, which discharges high-temperature, high-pressure refrigerant gas; S represents the compressor suction port, which draws in low-temperature, low-pressure refrigerant gas; E is typically the interface connecting to the indoor heat exchanger and plays an important role in switching between cooling and heating; C is generally the interface connecting to the outdoor heat exchanger and is used for controlling the refrigerant circulation direction in the system.

[0071] In cooling mode, the compressor first compresses the refrigerant into a high-temperature, high-pressure gaseous state, which is then discharged into the four-way valve through port D (compressor discharge port). At this time, the internal passage of the four-way valve connects D and C, and E and S. The high-temperature, high-pressure refrigerant enters the outdoor heat exchanger (which acts as a condenser at this time) through port C. In the outdoor heat exchanger, the refrigerant releases heat to the outside air and condenses from a gaseous state into a high-pressure liquid state. The high-pressure liquid refrigerant flows through the expansion valve, where it is throttled and depressurized into a low-temperature, low-pressure gas-liquid mixture. This gas-liquid mixture enters the indoor heat exchanger (which acts as an evaporator at this time), where it absorbs heat from the indoor air and evaporates into a gaseous state. The gaseous refrigerant returns to the four-way valve through port E, and is then drawn into the compressor through port S (compressor suction port), completing the refrigeration cycle.

[0072] In heating mode, the compressor discharges high-temperature, high-pressure gaseous refrigerant, which enters the four-way valve through port D. At this time, the internal passages of the four-way valve connect D and E, and C and S. The high-temperature, high-pressure refrigerant enters the indoor heat exchanger (acting as a condenser) through port E. In the indoor heat exchanger, the high-temperature, high-pressure refrigerant releases heat to the indoor air, condensing into a liquid state. The released heat raises the indoor temperature, achieving heating. The liquid refrigerant is then throttled and depressurized by the expansion valve, becoming a low-temperature, low-pressure gas-liquid mixture. This gas-liquid mixture enters the outdoor heat exchanger (acting as an evaporator), where it absorbs heat from the outdoor air and evaporates into a gaseous state. The gaseous refrigerant returns to the four-way valve through port C, and is then drawn into the compressor through port S, completing the heating cycle.

[0073] It should be noted that the compressor in the air conditioning system 110 shown in Figure 7 can be the compressor 1 in Figures 2 and 3, the outdoor heat exchanger can be the outdoor heat exchanger 2 in Figures 2 and 3, the four-way valve can be the first four-way valve 4 in Figures 2 and 3, the indoor heat exchanger can be the indoor heat exchanger 5 in Figures 2 and 3, and the expansion valve can be the first electronic expansion valve 6 in Figures 2 and 3.

[0074] Referring to Figures 6 and 7, outdoor unit 102 refers to an important component of the cooling and heating cycle, including compressor 1 and outdoor heat exchanger 2, while indoor unit 101 includes indoor heat exchanger 5. An expansion valve can be installed in either indoor unit 101 or outdoor unit 102, depending on design requirements.

[0075] In this embodiment, the refrigerant circulation loop allows the refrigerant to circulate within a circuit consisting of a compressor, condenser, expansion valve, and evaporator. One of the condensers and evaporator is an outdoor heat exchanger 2, and the other is an indoor heat exchanger 5. The indoor heat exchanger 5 exchanges heat with the air inside the indoor unit 101, and the outdoor heat exchanger 102 exchanges heat with the outdoor air, thereby fulfilling the cooling or heating requirements of the air conditioning system 110.

[0076] In some embodiments, the indoor unit 101 further includes an indoor fan, which is located near the return air vent or the air outlet of the indoor heat exchanger 5, and is used to deliver the heat-exchanged air into the room. The indoor fan includes multiple speed settings, which can be used to change the airflow speed at the air outlet.

[0077] In some embodiments, a guide vane is provided at the air outlet. The guide vane adjusts the outflow direction of the air flowing through the air outlet by changing its relative rotation angle with the air outlet, thereby affecting the indoor air temperature stratification.

[0078] In some embodiments, the controller 71 is further configured to: control the multi-split air conditioning system 100 to operate in different working modes in response to a second control command, and control the state of each component in the regulating unit 130 in different working modes, thereby regulating the on / off state between the refrigerant circulation loop and the water tank branch 22, and regulating the on / off state between the outdoor heat exchanger 2 and the indoor heat exchanger group in the refrigerant circulation loop, so that the refrigerant that does not participate in heat exchange in at least one of the refrigerant circulation loop and the water tank branch 22 flows back to the compressor 1 based on the pressure difference between the flow path and the inlet of the compressor 1; wherein the second control command includes the first control command.

[0079] In some embodiments, the operator can send a second control command via a terminal, and the second control command includes the first control command, so that the controller 71 controls the multi-split air conditioning system 100 to operate in different working modes. The working modes include, for example, one of: cooling mode, heating mode, water tank separate heating mode, first cooling and water tank heating mode, second cooling and water tank heating mode, heating and water tank heating mode, and defrosting mode. The heat recovery amount in the first cooling and water tank heating mode is lower than the heat recovery amount in the second cooling and water tank heating mode. That is, the first cooling and water tank heating mode is an incomplete heat recovery mode with lower thermal efficiency but higher energy saving, while the second cooling and water tank heating mode is a complete heat recovery mode with higher thermal efficiency but lower energy saving.

[0080] In some embodiments, the controller 71, under different operating modes, controls the state of each component in the regulating unit 130, thereby adjusting the on / off state between the refrigerant circulation loop and the water tank branch 22, as well as the on / off state between the outdoor heat exchanger 2 and the indoor heat exchanger group in the refrigerant circulation loop. This allows the refrigerant that does not participate in heat exchange in at least one of the refrigerant circulation loop and the water tank branch 22 to flow back to the compressor 1 based on the pressure difference between its flow path and the inlet of the compressor 1. This avoids refrigerant stagnation, ensures the amount of refrigerant in the air conditioning system 110 during operation, and thus helps to improve the cooling efficiency of the air conditioning system 110.

[0081] The multi-split air conditioning system 100 provided in this application embodiment includes an air conditioning system 110, a hot water system 120, an adjustment unit 130, and a controller 71 connected to each other. The hot water system 120 can be used as a condenser. The controller 71 responds to a second control command to control the multi-split air conditioning system 100 to operate in different working modes, thereby enriching the working modes of the multi-split air conditioning system 100 and improving its intelligence. At the same time, the controller 71 controls the state of each component in the adjustment unit 130 in different working modes, thereby adjusting the on / off state between the refrigerant circulation loop and the water tank branch 22, as well as adjusting the on / off state between the outdoor heat exchanger 2 and the indoor heat exchanger group in the refrigerant circulation loop. This allows the refrigerant that does not participate in heat exchange in at least one of the refrigerant circulation loop and the water tank branch 22 to flow back to the compressor 1 based on the pressure difference between its flow path and the inlet of the compressor 1. This can avoid refrigerant stagnation, ensure the amount of refrigerant during the operation of the air conditioning system 110, and thus help improve the cooling efficiency of the air conditioning system 110.

[0082] Figure 8 is a schematic diagram of the structure of an adjustment unit according to an embodiment of the present invention. As shown in Figure 8, in some embodiments of this application, the adjustment unit 130 includes a first switching component 131, a second switching component 132, a first throttling control component 133, a flow adjustment component 134, a third switching component 135, and a second throttling control component 136.

[0083] One end of the first switching assembly 131 is connected to the outlet of the compressor 1, and the other end is connected to the first interface of the first four-way valve 4. The first switching assembly 131 is used to control the on / off state between the outlet of the compressor 1 and the refrigerant circulation loop. The second switching assembly 132 is disposed on the first water tank branch 221. One end of the second switching assembly 132 is connected to the outlet of the compressor 1, and the other end is connected to one end of the water tank heat exchanger 21. The second switching assembly 132 is used to control the on / off state between the first water tank branch 221 and the refrigerant circulation loop. One end of the first throttling control assembly 133 is connected to the refrigerant circulation loop, and the other end is connected to the inlet of the compressor 1 and the fourth interface of the first four-way valve 4. The first throttling control assembly 133 is used to control the refrigerant flow back or not back to the compressor 1 in at least one of the outdoor heat exchanger 2 and the indoor heat exchanger assembly through its own on / off state. The flow regulating assembly 134 is disposed in the second water tank. On branch 222, one end of flow regulating component 134 is connected to the other end of water tank heat exchanger 21, and the other end of flow regulating component 134 is connected to one end of expansion valve assembly and one end of outdoor electronic expansion valve 3. Flow regulating component 134 is used to regulate the refrigerant flow rate out of water tank heat exchanger 21. One end of third switch component 135 is connected to one end of outdoor electronic expansion valve 3, and the other end of third switch component 135 is connected to one end of expansion valve assembly and one end of flow regulating component 134. Third switch component 135 is used to control the on / off state between indoor heat exchanger assembly and outdoor heat exchanger 2, and to control the on / off state between second water tank branch 222 and outdoor heat exchanger 2. One end of second throttling control component 136 is connected to first water tank branch 221, and the other end of second throttling control component 136 is connected to the inlet and fourth interface of compressor 1. Second throttling control component 136 is used to allow refrigerant in water tank branch 22 to flow back or not flow back to compressor 1 through its own on / off state.

[0084] In some embodiments, the first switching assembly 131 is the gas solenoid valve 7 shown in Figures 2 and 3, with its two ends connected to the outlet of the compressor 1 and the first interface of the first four-way valve 4, respectively. The first switching assembly 131 is used to control the on / off state between the outlet of the compressor 1 and the refrigerant circulation loop.

[0085] In some embodiments, the second switching assembly 132 includes a second four-way valve 8 disposed on the first water tank branch 221 as shown in Figures 2 and 3. The fifth port of the second four-way valve 8 is connected to the outlet of the compressor 1, the sixth port of the second four-way valve 8 is closed, the seventh port of the second four-way valve 8 is connected to one end of the water tank heat exchanger 21, and the eighth port of the second four-way valve 8 is connected to the inlet of the compressor 1. By switching the connection states of different ports of the second four-way valve 8, the on / off state between the first water tank branch 221 and the refrigerant circulation loop can be controlled.

[0086] In some embodiments, the fifth port of the second four-way valve 8 is the upper port of the second four-way valve 8 in Figures 2 and 3, and the fifth port is connected to the outlet of the compressor 1. The sixth port of the second four-way valve 8 is the right port of the second four-way valve 8 in Figures 2 and 3, and the sixth port is closed. The seventh port of the second four-way valve 8 is the left port of the second four-way valve 8 in Figures 2 and 3, and the seventh port is connected to one end of the water tank heat exchanger 21. The eighth port of the second four-way valve 8 is the lower port of the second four-way valve 8 in Figures 2 and 3, and the eighth port is connected to the inlet of the compressor 1.

[0087] In some embodiments, the second switching assembly 132 further includes a first solenoid valve 9 disposed on the first water tank branch 221. One end of the first solenoid valve 9 is connected to the outlet of the compressor 1, and the other end of the first solenoid valve 9 is connected to the fifth interface of the second four-way valve 8. By controlling the opening and closing state of the second switching assembly 132, the on / off state between the first water tank branch and the refrigerant circulation loop can be controlled.

[0088] In some embodiments, the first throttling control assembly 133 comprises a first capillary tube 10 and a second solenoid valve 11 connected in series in Figures 2 and 3. One end of the first capillary tube 10 is connected to the other end of the gas solenoid valve 7 and the first interface of the first four-way valve 4. The other end of the first capillary tube 10 is connected to one end of the second solenoid valve 11. The other end of the second solenoid valve 11 is connected to the inlet of the compressor 1 and the fourth interface of the first four-way valve 4. The first throttling control assembly 133 allows refrigerant in at least one of the outdoor heat exchanger 2 and the indoor heat exchanger assembly to either flow back to or not flow back to the compressor 1.

[0089] In some embodiments, the flow regulating component 134 is the second electronic expansion valve 12 provided on the second water tank branch 222 in Figures 2 and 3. One end of the second electronic expansion valve 12 is connected to the other end of the water tank heat exchanger 21, and the other end of the second electronic expansion valve 12 is connected to one end of the expansion valve assembly and one end of the outdoor electronic expansion valve 3. The flow regulating component 134 can regulate the flow rate of the refrigerant flowing out of the water tank heat exchanger 21.

[0090] In some embodiments, the third switching assembly 135 is the liquid solenoid valve 13 shown in Figures 2 and 3. One end of the liquid solenoid valve 13 is connected to one end of the outdoor electronic expansion valve 3, and the other end of the liquid solenoid valve 13 is connected to one end of the expansion valve assembly and one end of the flow regulating assembly 134. The third switching assembly 135 is used to control the on / off state between the indoor heat exchanger assembly and the outdoor heat exchanger 2, as well as to control the on / off state between the second water tank branch and the outdoor heat exchanger 2.

[0091] In some embodiments, the second throttling control assembly 136 comprises a second capillary tube 14 and a third solenoid valve 15 connected in series in FIG. 3. One end of the second capillary tube 14 is connected to the first water tank branch 221, and the other end of the second capillary tube 14 is connected to one end of the third solenoid valve 15. The other end of the third solenoid valve 15 is connected to the inlet of the compressor 1 and the fourth port of the first four-way valve 4. The second throttling control assembly 136 is used to control the refrigerant in the water tank branch 22 to either flow back to or not flow back to the compressor 1 based on its own on / off state.

[0092] The multi-split air conditioning system 100 provided in this application embodiment, through the cooperation of the first switch assembly 131, the second switch assembly 132, the first throttling control assembly 133, the flow regulating assembly 134, the third switch assembly 135, and the second throttling control assembly 136, enables the regulating unit 130 to regulate the on / off state between the refrigerant circulation loop and the water tank branch 22, as well as the on / off state between the outdoor heat exchanger 2 and the indoor heat exchanger group in the refrigerant circulation loop, thereby facilitating the control of the multi-split air conditioning system 100.

[0093] The multi-split air conditioning system 100 provided in this application embodiment has all valves centrally located in the outdoor unit 102 of the air conditioning system 110, while the indoor unit module of the air conditioning system 110 only includes the indoor heat exchanger 5. The indoor unit 101 can significantly reduce mechanical noise and operating vibration, thereby effectively reducing the indoor noise level.

[0094] Figure 9 is a schematic diagram of refrigerant flow in a refrigeration mode according to some embodiments of the present application, and Figure 10 is a schematic diagram of refrigerant flow in a refrigeration mode according to other embodiments of the present application.

[0095] In some embodiments, as shown in FIG9, when the regulating unit 130 does not include the second throttling control component 136 and the second switching component 132 does not include the first solenoid valve 9, the operating mode includes the cooling mode; when controlling the multi-split air conditioning system 100 to operate in the cooling mode in response to the second control command, the controller 71 is configured to: control the first and second interfaces of the first four-way valve 4 to be open, and control the third and fourth interfaces of the first four-way valve 4 to be open; control the outdoor electronic expansion valve 3 to be fully open; control the multiple first electronic expansion valves 6 to be open; control the gas solenoid valve 7 to be fully open; control the liquid solenoid valve 13 to be fully open; control the second electronic expansion valve 12 to be closed; control the second solenoid valve 11 to be closed; control the fifth and sixth interfaces of the second four-way valve 8 to be open, and control the seventh and eighth interfaces of the second four-way valve 8 to be open.

[0096] In some embodiments, as shown in FIG9, when the multi-split air conditioning system 100 is running in cooling mode, the refrigerant flows out of the compressor 1 and flows sequentially through the gas solenoid valve 7, the first four-way valve 4, the outdoor heat exchanger 2, the outdoor electronic expansion valve 3, the liquid solenoid valve 13, multiple first electronic expansion valves 6, multiple indoor heat exchangers 5 and the first four-way valve 4 before flowing back into the compressor 1 to complete the refrigerant cycle.

[0097] In some embodiments, as shown in FIG9, when the multi-split air conditioning system 100 is operating in cooling mode, since the hot water system 120 is not involved, refrigerant is retained in the water tank branch 22. The refrigerant retained in the water tank branch 22 flows back to the compressor 1 through the pipeline between the sixth port of the second four-way valve 8 and the inlet of the compressor 1 based on the pressure difference between the flow path and the compressor 1 inlet. This can avoid refrigerant retention, ensure the amount of refrigerant during the operation of the air conditioning system 110, and thus help improve the cooling efficiency of the air conditioning system 110.

[0098] In some embodiments, as shown in FIG10, when the regulating unit 130 includes a second throttling control component 136 and the second switching component 132 includes a first solenoid valve 9, the operating mode includes a cooling mode; when controlling the multi-split air conditioning system 100 to operate in cooling mode in response to a second control command, the controller 71 is configured to: control the first and second interfaces of the first four-way valve 4 to be open, and control the third and fourth interfaces of the first four-way valve 4 to be open; control the outdoor electronic expansion valve 3 to be fully open; control multiple first electronic expansion valves 6 to be open; control the gas solenoid valve 7 to be fully open; control the liquid solenoid valve 13 to be fully open; control the second electronic expansion valve 12 to be closed; control the second solenoid valve 11 to be closed; control the fifth and seventh interfaces of the second four-way valve 8 to be open, and control the sixth and eighth interfaces of the second four-way valve 8 to be open, and control the first solenoid valve 9 to be closed, and control the third solenoid valve 15 to be open.

[0099] In some embodiments, as shown in FIG10, when the multi-split air conditioning system 100 is running in cooling mode, the refrigerant flows out of the compressor 1 and flows sequentially through the gas solenoid valve 7, the first four-way valve 4, the outdoor heat exchanger 2, the outdoor electronic expansion valve 3, the liquid solenoid valve 13, multiple first electronic expansion valves 6, multiple indoor heat exchangers 5 and the first four-way valve 4 before flowing back into the compressor 1 to complete the refrigerant cycle.

[0100] In some embodiments, as shown in FIG10, when the multi-split air conditioning system 100 is operating in cooling mode, since the hot water system 120 is not involved, refrigerant is retained in the water tank branch 22. The refrigerant retained in the water tank branch 22 flows back to the compressor 1 through the second capillary tube 14 and the third solenoid valve 15 based on the pressure difference between the flow path and the inlet of the compressor 1. This can avoid refrigerant retention, ensure the amount of refrigerant during the operation of the air conditioning system 110, and thus help improve the cooling efficiency of the air conditioning system 110.

[0101] In the multi-split air conditioning system 100 provided in this application embodiment, when the controller 71 controls the corresponding valve to open in response to the second control command to control the multi-split air conditioning system 100 to operate in cooling mode, the refrigerant flows sequentially through the outdoor heat exchanger 2 and multiple indoor heat exchangers 5, and the refrigerant in the water tank branch 22 that does not participate in heat exchange flows back to the compressor 1 based on the pressure difference between its flow path and the inlet of the compressor 1. This can avoid refrigerant stagnation, ensure the amount of refrigerant during the operation of the air conditioning system 110, and thus help improve the cooling efficiency of the air conditioning system 110.

[0102] Figure 11 is a schematic diagram of the refrigerant flow direction in the heating mode according to some embodiments of the present application, and Figure 12 is a schematic diagram of the refrigerant flow direction in the heating mode according to other embodiments of the present application.

[0103] In some embodiments, as shown in FIG11, when the regulating unit 130 does not include the second throttling control component 136 and the second switching component 132 does not include the first solenoid valve 9, the operating mode includes the heating mode; when controlling the multi-split air conditioning system 100 to operate in the heating mode in response to the second control command, the controller 71 is configured to: control the first and third interfaces of the first four-way valve 4 to be open, and control the second and fourth interfaces of the first four-way valve 4 to be open; control the outdoor electronic expansion valve 3 to be open; control the plurality of first electronic expansion valves 6 to be open; control the gas solenoid valve 7 to be fully open; control the liquid solenoid valve 13 to be fully open; control the second electronic expansion valve 12 to be closed; control the second solenoid valve 11 to be closed; control the fifth and sixth interfaces of the second four-way valve 8 to be open, and control the seventh and eighth interfaces of the second four-way valve 8 to be open.

[0104] In some embodiments, as shown in FIG11, when the multi-split air conditioning system 100 is operating in heating mode, the refrigerant flows out of the compressor 1 and flows sequentially through the gas solenoid valve 7, the first four-way valve 4, multiple indoor heat exchangers 5, multiple first electronic expansion valves 6, liquid solenoid valve 13, outdoor electronic expansion valve 3, outdoor heat exchanger 2 and the first four-way valve 4 before flowing back into the compressor 1 to complete the refrigerant circulation.

[0105] In some embodiments, as shown in FIG11, when the multi-split air conditioning system 100 is operating in heating mode, since the hot water system 120 is not involved, refrigerant is retained in the water tank branch 22. The refrigerant retained in the water tank branch 22 flows back to the compressor 1 through the pipeline between the sixth port of the second four-way valve 8 and the inlet of the compressor 1 based on the pressure difference between the flow path and the inlet of the compressor 1. This can avoid refrigerant retention, ensure the amount of refrigerant during the operation of the air conditioning system 110, and thus help improve the cooling efficiency of the air conditioning system 110.

[0106] In some embodiments, as shown in FIG12, when the regulating unit 130 includes a second throttling control component 136 and the second switching component 132 includes a first solenoid valve 9, the operating mode includes a heating mode; when controlling the multi-split air conditioning system 100 to operate in heating mode in response to a second control command, the controller 71 is configured to: control the first and third interfaces of the first four-way valve 4 to be open, and control the second and fourth interfaces of the first four-way valve 4 to be open; control the outdoor electronic expansion valve 3 to be open; control multiple first electronic expansion valves 6 to be open; control the gas solenoid valve 7 to be fully open; control the liquid solenoid valve 13 to be fully open; control the second electronic expansion valve 12 to be closed; control the second solenoid valve 11 to be closed; control the fifth and seventh interfaces of the second four-way valve 8 to be open, and control the sixth and eighth interfaces of the second four-way valve 8 to be open, and control the first solenoid valve 9 to be closed, and control the third solenoid valve 15 to be open.

[0107] In some embodiments, as shown in FIG12, when the multi-split air conditioning system 100 is operating in heating mode, the refrigerant flows out of the compressor 1 and flows sequentially through the gas solenoid valve 7, the first four-way valve 4, multiple indoor heat exchangers 5, multiple first electronic expansion valves 6, liquid solenoid valve 13, outdoor electronic expansion valve 3, outdoor heat exchanger 2 and the first four-way valve 4 before flowing back into the compressor 1 to complete the refrigerant circulation.

[0108] In some embodiments, as shown in FIG12, when the multi-split air conditioning system 100 is operating in heating mode, since the hot water system 120 is not involved, refrigerant is retained in the water tank branch 22. The refrigerant retained in the water tank branch 22 flows back to the compressor 1 through the second capillary tube 14 and the third solenoid valve 15 based on the pressure difference between the flow path and the inlet of the compressor 1. This can avoid refrigerant retention, ensure the amount of refrigerant during the operation of the air conditioning system 110, and thus help improve the cooling efficiency of the air conditioning system 110.

[0109] In the multi-split air conditioning system 100 provided in this application embodiment, when the controller 71 controls the corresponding valve to open in response to the second control command to control the multi-split air conditioning system 100 to operate in heating mode, the refrigerant flows through multiple indoor heat exchangers 5 and outdoor heat exchangers 2 in sequence, and the refrigerant in the water tank branch 22 that does not participate in heat exchange flows back to the compressor 1 based on the pressure difference between the flow path and the inlet of the compressor 1. This can avoid refrigerant retention, ensure the amount of refrigerant during the operation of the air conditioning system 110, and thus help improve the cooling efficiency of the air conditioning system 110.

[0110] Figure 13 is a schematic diagram of the refrigerant flow in a water tank individual heating mode according to some embodiments of the present application, and Figure 14 is a schematic diagram of the refrigerant flow in a water tank individual heating mode according to other embodiments of the present application.

[0111] In some embodiments, as shown in FIG13, when the regulating unit 130 does not include the second throttling control component 136 and the second switching component 132 does not include the first solenoid valve 9, the operating mode includes a water tank individual heating mode; when the multi-split air conditioning system 100 is controlled to operate in the water tank individual heating mode in response to the second control command, the controller 71 is configured to: control the first and third interfaces of the first four-way valve 4 to be open, and control the second and fourth interfaces of the first four-way valve 4 to be open; control the outdoor electronic expansion valve 3 to be open; control the plurality of first electronic expansion valves 6 to be closed; control the gas solenoid valve 7 to be closed; control the liquid solenoid valve 13 to be fully open; control the second electronic expansion valve 12 to be fully open; control the second solenoid valve 11 to be open; control the fifth and seventh interfaces of the second four-way valve 8 to be open, and control the sixth and eighth interfaces of the second four-way valve 8 to be open.

[0112] In some embodiments, as shown in FIG13, when the multi-split air conditioning system 100 is operating in the water tank individual heating mode, the refrigerant flows out of the compressor 1 and flows sequentially through the second four-way valve 8, the water tank heat exchanger 21, the second electronic expansion valve 12, the liquid solenoid valve 13, the outdoor electronic expansion valve 3, the outdoor heat exchanger 2, and the first four-way valve 4 before flowing back into the compressor 1 to complete the refrigerant circulation.

[0113] In some embodiments, as shown in FIG13, when the multi-split air conditioning system 100 operates in the water tank individual heating mode, since multiple indoor heat exchangers 5 are not involved, refrigerant is retained in the refrigerant circulation loop. The refrigerant retained in the refrigerant circulation loop flows back to the compressor 1 through the first capillary tube 10 and the second solenoid valve 11 based on the pressure difference between the flow path and the inlet of the compressor 1. This can avoid refrigerant retention, ensure the amount of refrigerant during the operation of the air conditioning system 110, and thus help improve the cooling efficiency of the air conditioning system 110.

[0114] In some embodiments, as shown in FIG14, when the regulating unit 130 includes a second throttling control component 136 and the second switching component 132 includes a first solenoid valve 9, the operating mode includes a water tank individual heating mode; when the multi-split air conditioning system 100 is controlled to operate in the water tank individual heating mode in response to a second control command, the controller 71 is configured to: control the first and third interfaces of the first four-way valve 4 to be open, and control the second and fourth interfaces of the first four-way valve 4 to be open; control the outdoor electronic expansion valve 3 to be open; control the multiple first electronic expansion valves 6 to be closed; control the gas solenoid valve 7 to be closed; control the liquid solenoid valve 13 to be fully open; control the second electronic expansion valve 12 to be fully open; control the second solenoid valve 11 to be open; control the fifth and seventh interfaces of the second four-way valve 8 to be open, and control the sixth and eighth interfaces of the second four-way valve 8 to be open, and control the first solenoid valve 9 to be open, and control the third solenoid valve 15 to be closed.

[0115] In some embodiments, as shown in FIG14, when the multi-split air conditioning system 100 operates in the water tank individual heating mode, the refrigerant flows out of the compressor 1 and flows sequentially through the first solenoid valve 9, the second four-way valve 8, the water tank heat exchanger 21, the second electronic expansion valve 12, the liquid solenoid valve 13, the outdoor electronic expansion valve 3, the outdoor heat exchanger 2, and the first four-way valve 4 before flowing back into the compressor 1 to complete the refrigerant circulation.

[0116] In some embodiments, as shown in FIG14, when the multi-split air conditioning system 100 operates in the water tank individual heating mode, since multiple indoor heat exchangers 5 are not involved, refrigerant is retained in the refrigerant circulation loop. The refrigerant retained in the refrigerant circulation loop flows back to the compressor 1 through the first capillary tube 10 and the second solenoid valve 11 based on the pressure difference between the flow path and the inlet of the compressor 1. This can avoid refrigerant retention, ensure the amount of refrigerant during the operation of the air conditioning system 110, and thus help improve the cooling efficiency of the air conditioning system 110.

[0117] In the multi-split air conditioning system 100 provided in this application embodiment, when the controller 71 controls the multi-split air conditioning system 100 to operate in the water tank individual heating mode in response to the second control command, the corresponding valve is opened so that the refrigerant flows sequentially through the water tank heat exchanger 21 and the outdoor heat exchanger 2. The refrigerant that does not participate in heat exchange in the refrigerant circulation loop is returned to the compressor 1 based on the pressure difference between its flow path and the inlet of the compressor 1. This can avoid refrigerant stagnation, ensure the amount of refrigerant during the operation of the air conditioning system 110, and thus help improve the cooling efficiency of the air conditioning system 110.

[0118] Figure 15 is a schematic diagram of the refrigerant flow in a first cooling and water tank heating mode according to some embodiments of the present application, and Figure 16 is a schematic diagram of the refrigerant flow in a first cooling and water tank heating mode according to other embodiments of the present application.

[0119] In some embodiments, as shown in FIG15, when the regulating unit 130 does not include the second throttling control component 136 and the second switching component 132 does not include the first solenoid valve 9, the operating mode includes a first cooling and water tank heating mode; when the multi-split air conditioning system 100 is controlled to operate in the first cooling and water tank heating mode in response to the second control command, the controller 71 is configured to: control the first and second interfaces of the first four-way valve 4 to be open, and control the third and fourth interfaces of the first four-way valve 4 to be open; control the outdoor electronic expansion valve 3 to be fully open; control the multiple first electronic expansion valves 6 to be open; control the gas solenoid valve 7 to be fully open; control the liquid solenoid valve 13 to be fully open; control the second electronic expansion valve 12 to be fully open; control the second solenoid valve 11 to be closed; control the fifth and seventh interfaces of the second four-way valve 8 to be open, and control the sixth and eighth interfaces of the second four-way valve 8 to be open.

[0120] In some embodiments, as shown in FIG15, when the multi-split air conditioning system 100 operates in the first cooling and water tank heating mode, the refrigerant flows out of the compressor 1 and flows sequentially through the gas solenoid valve 7, the first four-way valve 4, the outdoor heat exchanger 2, the outdoor electronic expansion valve 3, the liquid solenoid valve 13, multiple first electronic expansion valves 6, multiple indoor heat exchangers 5 and the first four-way valve 4 before flowing back into the compressor 1. The other path flows sequentially through the second four-way valve 8, the water tank heat exchanger 21, the second electronic expansion valve 12, multiple first electronic expansion valves 6, multiple indoor heat exchangers 5 and the first four-way valve 4 before flowing back into the compressor 1, thus completing the refrigerant circulation.

[0121] In some embodiments, as shown in FIG16, when the regulating unit 130 includes a second throttling control component 136 and the second switching component 132 includes a first solenoid valve 9, the operating mode includes a first cooling and water tank heating mode; when the multi-split air conditioning system 100 is controlled to operate in the first cooling and water tank heating mode in response to a second control command, the controller 71 is configured to: control the first and second interfaces of the first four-way valve 4 to be open, and control the third and fourth interfaces of the first four-way valve 4 to be open; control the outdoor electronic expansion valve 3 to be fully open; control multiple first electronic expansion valves 6 to be open; control the gas solenoid valve 7 to be fully open; control the liquid solenoid valve 13 to be fully open; control the second electronic expansion valve 12 to be fully open; control the second solenoid valve 11 to be closed; control the fifth and seventh interfaces of the second four-way valve 8 to be open, and control the sixth and eighth interfaces of the second four-way valve 8 to be open, and control the first solenoid valve 9 to be fully open, and control the third solenoid valve 15 to be closed.

[0122] In some embodiments, as shown in FIG16, when the multi-split air conditioning system 100 operates in the first cooling and water tank heating mode, after the refrigerant flows out of the compressor 1, one path flows sequentially through the gas solenoid valve 7, the first four-way valve 4, the outdoor heat exchanger 2, the outdoor electronic expansion valve 3, the liquid solenoid valve 13, multiple first electronic expansion valves 6, multiple indoor heat exchangers 5 and the first four-way valve 4 before flowing back into the compressor 1. The other path flows sequentially through the first solenoid valve 9, the second four-way valve 8, the water tank heat exchanger 21, the second electronic expansion valve 12, multiple first electronic expansion valves 6, multiple indoor heat exchangers 5 and the first four-way valve 4 before flowing back into the compressor 1, thus completing the refrigerant circulation.

[0123] The multi-split air conditioning system 100 provided in this application embodiment, when responding to the second control command to control the multi-split air conditioning system 100 to operate in the first cooling and water tank heating mode, the controller 71 controls the corresponding valve to open so that the refrigerant flows sequentially through the outdoor heat exchanger 2, the water tank heat exchanger 21 and multiple indoor heat exchangers 5, and uses the heat generated during the air conditioning operation to heat the water, organically combining the cooling and hot water functions, which helps to improve energy utilization efficiency.

[0124] Figure 17 is a schematic diagram of the refrigerant flow in a second cooling and water tank heating mode according to some embodiments of the present application, and Figure 18 is a schematic diagram of the refrigerant flow in a second cooling and water tank heating mode according to other embodiments of the present application.

[0125] In some embodiments, as shown in FIG17, when the regulating unit 130 does not include the second throttling control component 136 and the second switching component 132 does not include the first solenoid valve 9, the operating mode includes the second cooling and water tank heating mode; when the multi-split air conditioning system 100 is controlled to operate in the second cooling and water tank heating mode in response to the second control command, the controller 71 is configured to: control the first and second interfaces of the first four-way valve 4 to be open, and control the third and fourth interfaces of the first four-way valve 4 to be open; control the outdoor electronic expansion valve 3 to be closed; control the plurality of first electronic expansion valves 6 to be open; control the gas solenoid valve 7 to be closed; control the liquid solenoid valve 13 to be closed; control the second electronic expansion valve 12 to be fully open; control the second solenoid valve 11 to be open; control the fifth and seventh interfaces of the second four-way valve 8 to be open, and control the sixth and eighth interfaces of the second four-way valve 8 to be open.

[0126] In some embodiments, as shown in FIG17, when the multi-split air conditioning system 100 operates in the second cooling and water tank heating mode, the refrigerant flows out of the compressor 1 and flows sequentially through the second four-way valve 8, the water tank heat exchanger 21, the second electronic expansion valve 12, multiple first electronic expansion valves 6, multiple indoor heat exchangers 5, and the first four-way valve 4 before flowing back into the compressor 1 to complete the refrigerant cycle. It can be seen that in the second cooling and water tank heating mode, the refrigerant flows sequentially through the water tank heat exchanger 21 and multiple indoor heat exchangers 5. Compared with the first cooling and water tank heating mode, in which the refrigerant flows sequentially through the outdoor heat exchanger 2, the water tank heat exchanger 21, and multiple indoor heat exchangers 5, the refrigerant in the second cooling and water tank heating mode does not need to flow through the outdoor heat exchanger 2, reducing heat loss. Therefore, the heat recovery amount in the second cooling and water tank heating mode is higher than that in the first cooling and water tank heating mode.

[0127] In some embodiments, as shown in FIG17, when the multi-split air conditioning system 100 operates in the second cooling and water tank heating mode, since the outdoor heat exchanger 2 is not involved, refrigerant is retained in the refrigerant circulation loop. The refrigerant retained in the refrigerant circulation loop flows back to the compressor 1 through the first capillary tube 10 and the second solenoid valve 11 based on the pressure difference between the flow path and the inlet of the compressor 1. This can avoid refrigerant retention, ensure the amount of refrigerant during the operation of the air conditioning system 110, and thus help improve the cooling efficiency of the air conditioning system 110.

[0128] In some embodiments, as shown in FIG18, when the regulating unit 130 includes a second throttling control component 136 and the second switching component 132 includes a first solenoid valve 9, the operating mode includes a second cooling and water tank heating mode; when the multi-split air conditioning system 100 is controlled to operate in the second cooling and water tank heating mode in response to a second control command, the controller 71 is configured to: control the first and second interfaces of the first four-way valve 4 to be open, and control the third and fourth interfaces of the first four-way valve 4 to be open; control the outdoor electronic expansion valve 3 to be closed; control the plurality of first electronic expansion valves 6 to be open; control the gas solenoid valve 7 to be closed; control the liquid solenoid valve 13 to be closed; control the second electronic expansion valve 12 to be fully open; control the second solenoid valve 11 to be open; control the fifth and seventh interfaces of the second four-way valve 8 to be open, and control the sixth and eighth interfaces of the second four-way valve 8 to be open, and control the first solenoid valve 9 to be fully open, and control the third solenoid valve 15 to be closed.

[0129] In some embodiments, as shown in FIG18, when the multi-split air conditioning system 100 operates in the second cooling and water tank heating mode, the refrigerant flows out of the compressor 1 and flows sequentially through the first solenoid valve 9, the second four-way valve 8, the water tank heat exchanger 21, the second electronic expansion valve 12, multiple first electronic expansion valves 6, multiple indoor heat exchangers 5, and the first four-way valve 4 before flowing back into the compressor 1 to complete the refrigerant cycle. It can be seen that in the second cooling and water tank heating mode, the refrigerant flows sequentially through the water tank heat exchanger 21 and multiple indoor heat exchangers 5. Compared with the first cooling and water tank heating mode, in which the refrigerant flows sequentially through the outdoor heat exchanger 2, the water tank heat exchanger 21, and multiple indoor heat exchangers 5, the refrigerant in the second cooling and water tank heating mode does not need to flow through the outdoor heat exchanger 2, reducing heat loss. Therefore, the heat recovery amount in the second cooling and water tank heating mode is higher than that in the first cooling and water tank heating mode.

[0130] In some embodiments, as shown in FIG18, when the multi-split air conditioning system 100 operates in the second cooling and water tank heating mode, since the outdoor heat exchanger 2 is not involved, refrigerant is retained in the refrigerant circulation loop. The refrigerant retained in the refrigerant circulation loop flows back to the compressor 1 through the first capillary tube 10 and the second solenoid valve 11 based on the pressure difference between the flow path and the inlet of the compressor 1. This can avoid refrigerant retention, ensure the amount of refrigerant during the operation of the air conditioning system 110, and thus help improve the cooling efficiency of the air conditioning system 110.

[0131] The multi-split air conditioning system 100 provided in this application embodiment, when responding to a second control command to control the multi-split air conditioning system 100 to operate in a second cooling and water tank heating mode, the controller 71 controls the corresponding valve to open, so that the refrigerant flows sequentially through the water tank heat exchanger 21 and multiple indoor heat exchangers 5, using the heat generated during the air conditioning operation to heat the water, organically combining cooling and hot water functions, which helps to improve energy utilization efficiency. In addition, the refrigerant that does not participate in heat exchange in the refrigerant circulation loop flows back to the compressor 1 based on the pressure difference between its flow path and the inlet of the compressor 1, thereby avoiding refrigerant stagnation, ensuring the amount of refrigerant during the operation of the air conditioning system 110, and thus helping to improve the cooling efficiency of the air conditioning system 110.

[0132] Figure 19 is a schematic diagram of the refrigerant flow in the heating and water tank heating modes according to some embodiments of the present application, and Figure 20 is a schematic diagram of the refrigerant flow in the heating and water tank heating modes according to other embodiments of the present application.

[0133] In some embodiments, as shown in FIG19, when the regulating unit 130 does not include the second throttling control component 136 and the second switching component 132 does not include the first solenoid valve 9, the operating mode includes heating and water tank heating modes; when the multi-split air conditioning system 100 is controlled to operate in heating and water tank heating modes in response to the second control command, the controller 71 is configured to: control the first and third interfaces of the first four-way valve 4 to be open, and control the second and fourth interfaces of the first four-way valve 4 to be open; control the outdoor electronic expansion valve 3 to be open; control the multiple first electronic expansion valves 6 to be open; control the gas solenoid valve 7 to be fully open; control the liquid solenoid valve 13 to be fully open; control the second electronic expansion valve 12 to be fully open; control the second solenoid valve 11 to be closed; control the fifth and seventh interfaces of the second four-way valve 8 to be open, and control the sixth and eighth interfaces of the second four-way valve 8 to be open.

[0134] In some embodiments, as shown in FIG19, when the multi-split air conditioning system 100 is operating in heating and water tank heating modes, after the refrigerant flows out of the compressor 1, one path flows sequentially through the gas solenoid valve 7, the first four-way valve 4, multiple indoor heat exchangers 5, multiple first electronic expansion valves 6, the liquid solenoid valve 13, the outdoor electronic expansion valve 3, the outdoor heat exchanger 2, and the first four-way valve 4 before flowing back into the compressor 1. The other path flows sequentially through the second four-way valve 8, the water tank heat exchanger 21, the second electronic expansion valve 12, the liquid solenoid valve 13, the outdoor electronic expansion valve 3, the outdoor heat exchanger 2, and the first four-way valve 4 before flowing back into the compressor 1, thus completing the refrigerant circulation.

[0135] In some embodiments, as shown in FIG20, when the regulating unit 130 includes a second throttling control component 136 and the second switching component 132 includes a first solenoid valve 9, the operating mode includes heating and water tank heating modes; when controlling the multi-split air conditioning system 100 to operate in heating and water tank heating modes in response to a second control command, the controller 71 is configured to: control the first and third interfaces of the first four-way valve 4 to be open, and control the second and fourth interfaces of the first four-way valve 4 to be open; control the outdoor electronic expansion valve 3 to be open; control multiple first electronic expansion valves 6 to be open; control the gas solenoid valve 7 to be fully open; control the liquid solenoid valve 13 to be fully open; control the second electronic expansion valve 12 to be fully open; control the second solenoid valve 11 to be closed; control the fifth and seventh interfaces of the second four-way valve 8 to be open, and control the sixth and eighth interfaces of the second four-way valve 8 to be open, and control the first solenoid valve 9 to be fully open, and control the third solenoid valve 15 to be closed.

[0136] In some embodiments, as shown in FIG20, when the multi-split air conditioning system 100 is operating in heating and water tank heating modes, the refrigerant flows out of the compressor 1 and flows sequentially through the gas solenoid valve 7, the first four-way valve 4, multiple indoor heat exchangers 5, multiple first electronic expansion valves 6, the liquid solenoid valve 13, the outdoor electronic expansion valve 3, the outdoor heat exchanger 2, and the first four-way valve 4 before flowing back into the compressor 1. Another path flows sequentially through the first solenoid valve 9, the second four-way valve 8, the water tank heat exchanger 21, the second electronic expansion valve 12, the liquid solenoid valve 13, the outdoor electronic expansion valve 3, the outdoor heat exchanger 2, and the first four-way valve 4 before flowing back into the compressor 1, thus completing the refrigerant circulation.

[0137] The multi-split air conditioning system 100 provided in this application embodiment, in response to a second control command, controls the multi-split air conditioning system 100 to operate in heating and water tank heating modes. The controller 71 controls the corresponding valves to open so that the refrigerant flows sequentially through multiple indoor heat exchangers 5, water tank heat exchangers 21 and outdoor heat exchangers 2. The heat generated during the operation of the air conditioner is used to heat the water, organically combining the heating and hot water functions, which helps to improve energy utilization efficiency.

[0138] Figure 21 is a schematic diagram of refrigerant flow in a defrosting mode according to some embodiments of the present application, and Figure 22 is a schematic diagram of refrigerant flow in a defrosting mode according to other embodiments of the present application.

[0139] In some embodiments, as shown in FIG21, when the regulating unit 130 does not include the second throttling control component 136 and the second switching component 132 does not include the first solenoid valve 9, the operating mode includes a defrost mode; when controlling the multi-split air conditioning system 100 to operate in defrost mode in response to the first control command, the controller 71 is configured to: control the first and second interfaces of the first four-way valve 4 to be open, and control the third and fourth interfaces of the first four-way valve 4 to be open; control the outdoor electronic expansion valve 3 to be fully open; control the plurality of first electronic expansion valves 6 to be closed; control the gas solenoid valve 7 to be fully open; control the liquid solenoid valve 13 to be fully open; control the second electronic expansion valve 12 to be open; control the second solenoid valve 11 to be closed; control the fifth and sixth interfaces of the second four-way valve 8 to be open, and control the seventh and eighth interfaces of the second four-way valve 8 to be open.

[0140] In some embodiments, as shown in FIG22, when the multi-split air conditioning system 100 is running in defrost mode, the refrigerant flows out of the compressor 1 and flows sequentially through the gas solenoid valve 7, the first four-way valve 4, the outdoor heat exchanger 2, the outdoor electronic expansion valve 3, the liquid solenoid valve 13, the second electronic expansion valve 12, the water tank heat exchanger 21, and the second four-way valve 8 before flowing back into the compressor 1 to complete the refrigerant circulation.

[0141] In some embodiments, as shown in FIG22, when the regulating unit 130 includes a second throttling control component 136 and the second switching component 132 includes a first solenoid valve 9, the operating mode includes a defrost mode; when controlling the multi-split air conditioning system 100 to operate in defrost mode in response to a first control command, the controller 71 is configured to: control the first and second interfaces of the first four-way valve 4 to be open, and control the third and fourth interfaces of the first four-way valve 4 to be open; control the outdoor electronic expansion valve 3 to be fully open; control the plurality of first electronic expansion valves 6 to be closed; control the gas solenoid valve 7 to be fully open; control the liquid solenoid valve 13 to be fully open; control the second electronic expansion valve 12 to be open; control the second solenoid valve 11 to be closed; control the fifth and sixth interfaces of the second four-way valve 8 to be open, and control the seventh and eighth interfaces of the second four-way valve 8 to be open, and control the first solenoid valve 9 to be closed, and control the third solenoid valve 15 to be closed.

[0142] In some embodiments, as shown in FIG22, when the multi-split air conditioning system 100 is running in defrost mode, the refrigerant flows out of the compressor 1 and flows sequentially through the gas solenoid valve 7, the first four-way valve 4, the outdoor heat exchanger 2, the outdoor electronic expansion valve 3, the liquid solenoid valve 13, the second electronic expansion valve 12, the water tank heat exchanger 21, and the second four-way valve 8 before flowing back into the compressor 1 to complete the refrigerant circulation.

[0143] The multi-split air conditioning system 100 provided in this application embodiment, when responding to a first control command to control the multi-split air conditioning system 100 to operate in defrost mode, the controller 71 controls the corresponding valve to open, so that the refrigerant flows sequentially through the outdoor heat exchanger 2 and the water tank heat exchanger 21, using the water tank heat exchanger 21 as an evaporator, and heating the refrigerant in the water tank branch 22 through the water in the water tank 20. The heated refrigerant flows through the compressor 1 and exchanges heat with the outdoor heat exchanger 2 to defrost the outdoor heat exchanger 2, thereby transferring the heat in the water tank to the outdoor heat exchanger 2. This not only effectively speeds up the defrosting process, but also significantly reduces the impact on the indoor temperature, ensuring the efficient operation and stability of the air conditioning system 110 in low-temperature environments, thereby improving the overall operating performance and avoiding the negative impact of temperature fluctuations during the defrosting process on user comfort.

[0144] Figure 23 is a first installation schematic diagram of a subcooling device according to some embodiments of the present application; Figure 24 is a second installation schematic diagram of a subcooling device according to some embodiments of the present application; Figure 25 is a first installation schematic diagram of a subcooling device according to other embodiments of the present application; and Figure 26 is a second installation schematic diagram of a subcooling device according to other embodiments of the present application.

[0145] In some embodiments, the multi-split air conditioning system 100 further includes a subcooling device 16.

[0146] In some embodiments, as shown in Figures 23 and 25, the subcooling device 16 is connected to the second water tank branch 222. One end of the subcooling device 16 is connected to the other end of the water tank heat exchanger 21, and the other end of the subcooling device 16 is connected to one end of the expansion valve assembly and one end of the outdoor electronic expansion valve 3. The subcooling device 16 is used to exchange heat with the refrigerant in the second water tank branch to heat the water entering the water tank 20.

[0147] In some embodiments, as shown in Figures 24 and 26, the subcooling device 16 is connected to the refrigerant circulation loop. One end of the subcooling device 16 is connected to one end of the expansion valve assembly and the other end of the water tank heat exchanger 21, and the other end of the subcooling device 16 is connected to one end of the outdoor electronic expansion valve 3. The subcooling device 16 is used to exchange heat with the refrigerant in the refrigerant circulation loop to heat the water entering the water tank 20.

[0148] The multi-split air conditioning system 100 provided in this application embodiment is further provided with a subcooling device 16 on the second water tank branch 222 or the refrigerant circulation loop. The subcooling device 16 is used to exchange heat with the refrigerant in the second water tank branch 222 or the refrigerant circulation loop to heat the water entering the water tank 20, thereby helping to improve heat exchange efficiency and optimize system operating performance.

[0149] Figure 27 is a schematic diagram of the structure of a hot water system according to some embodiments of this application.

[0150] As shown in Figure 27, in some embodiments, the hot water system 120 includes an inlet 121, an outlet 122, and an air vent 123. An inlet valve 124 is installed on the inlet 121. The hot water system 120 also includes a high-pressure sensor 125 and a water level sensor 126. The high-pressure sensor 125 detects the pressure inside the water tank 20, and the water level sensor 126 detects the water level inside the water tank 20. The hot water system 120 also includes an electric auxiliary heating device 127, which uses electrical energy to heat the water in the water tank 20. The air vent 123 is used to expel air from the hot water system 120.

[0151] In summary, the multi-split air conditioning system 100 provided according to some embodiments of this application has the following beneficial effects:

[0152] First, according to the multi-split air conditioning system 100 provided in the embodiments of this application, the hot water storage tank 20 is used as the defrosting heat source. By transferring the heat in the water tank 20 to the outdoor heat exchanger, not only is the defrosting speed effectively accelerated, but the impact on the indoor temperature is also significantly reduced, ensuring the efficient operation and stability of the system in low-temperature environments, thereby improving the overall operating performance and avoiding the negative impact of temperature fluctuations during the defrosting process on user comfort.

[0153] Secondly, the multi-split air conditioning system 100 provided in this application embodiment differs from conventional heat pump products in that a water tank branch 22 leading to the water tank 20 is added to the pipeline from the compressor 1 outlet to the first four-way valve 4. This water tank branch 22 serves as part of the condenser for heating the water in the water tank 20, thus simultaneously meeting the needs of the air conditioning system 10 and the hot water system 120, organically combining cooling, heating, and domestic hot water functions. In practical applications, users no longer need to separately configure a gas water heater or an electric water heater, thereby saving equipment investment and space.

[0154] Meanwhile, the multi-split air conditioning system 100 provided in the embodiments of this application can effectively use the heat released indoors to heat the water in the water tank 20 in the cooling mode, so as to realize the simultaneous operation of air conditioning cooling and hot water preparation without the need for additional electric heating, thereby improving energy utilization efficiency and reducing energy consumption, and helping users reduce operating costs.

[0155] Finally, the multi-split air conditioning system 100 provided in the embodiments of this application utilizes a capillary tube as a throttling device to efficiently recover refrigerant retained in branches that are not in operation, ensuring full recycling of the refrigerant, thereby improving system efficiency and preventing efficiency decline or abnormal operation caused by refrigerant retention.

[0156] In summary, the multi-split air conditioning system 100 provided according to the embodiments of this application includes an air conditioning system 110, a hot water system 120, a regulating unit 130, and a controller 71 connected to each other. The water tank heat exchanger 21 in the hot water system 120 can be used as an evaporator. The controller 71 responds to a first control command and controls the multi-split air conditioning system 100 to operate in defrost mode. In defrost mode, the controller 71 controls the state of each component in the regulating unit 130, thereby controlling the disconnection between the refrigerant circulation loop and the water tank branch 22, and controlling the connection between the outdoor heat exchanger 2 and the indoor heat exchanger group in the refrigerant circulation loop. The system is disconnected so that the water tank heat exchanger 21 in the hot water system 120 can be used as an evaporator. The water in the water tank 20 heats the refrigerant in the water tank branch 22. The heated refrigerant flows through the compressor 1 and exchanges heat with the outdoor heat exchanger 2 to defrost the outdoor heat exchanger 2. This transfers the heat in the water tank 20 to the outdoor heat exchanger 2, which not only effectively speeds up the defrosting process but also significantly reduces the impact on the indoor temperature. This ensures the efficient operation and stability of the air conditioning system 110 in low-temperature environments, thereby improving the overall operating performance and avoiding the negative impact of temperature fluctuations during the defrosting process on user comfort.

[0157] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0158] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A multi-split air conditioning system, comprising: An air conditioning system, comprising a compressor, an outdoor heat exchanger, an outdoor electronic expansion valve, an expansion valve assembly, an indoor heat exchanger assembly, and a first four-way valve, wherein the compressor, the outdoor heat exchanger, the outdoor electronic expansion valve, the expansion valve assembly, the indoor heat exchanger assembly, and the first four-way valve form a refrigerant circulation loop to allow refrigerant to circulate within the refrigerant circulation loop; A hot water system, connected to the air conditioning system, the hot water system comprising: Water tank; A water tank heat exchanger is installed on the water tank; Water tank branch, the water tank heat exchanger is connected to the refrigerant circulation loop through the water tank branch; When the water tank heat exchanger is used as an evaporator, the refrigerant in the water tank branch can be heated by the water in the water tank. The heated refrigerant flows through the compressor and exchanges heat with the outdoor heat exchanger to defrost the outdoor heat exchanger. The regulating unit is connected to the refrigerant circulation loop and the water tank branch respectively; A controller, connected to the regulating unit, is configured to: In response to the first control command, the multi-split air conditioning system is controlled to operate in defrost mode. In defrost mode, the state of the regulating unit is controlled, thereby controlling the disconnection between the refrigerant circulation loop and the water tank branch, as well as the disconnection between the outdoor heat exchanger and the indoor heat exchanger group in the refrigerant circulation loop, so that the water tank heat exchanger is used as an evaporator. The refrigerant in the water tank branch is heated by the water in the water tank. The heated refrigerant flows through the compressor and exchanges heat with the outdoor heat exchanger to defrost the outdoor heat exchanger.

2. The multi-split air conditioning system according to claim 1, wherein, The first port of the first four-way valve is connected to the outlet of the compressor, the second port of the first four-way valve is connected to the outdoor heat exchanger, the third port of the first four-way valve is connected to the indoor heat exchanger assembly, and the fourth port of the first four-way valve is connected to the inlet of the compressor; the expansion valve assembly includes: multiple first electronic expansion valves connected in parallel, one end of each first electronic expansion valve is connected to one end of the outdoor electronic expansion valve, and the other end of each first electronic expansion valve is connected to one end of the corresponding indoor heat exchanger.

3. [Correction 31.07.2025 according to Rule 91] According to claim 1, the multi-split air conditioning system, wherein, The water tank branch includes: a first water tank branch and a second water tank branch; wherein, one end of the first water tank branch is connected to the outlet of the compressor, the other end of the first water tank branch is connected to one end of the water tank heat exchanger, one end of the second water tank branch is connected to the other end of the water tank heat exchanger, and the other end of the second water tank branch is connected to one end of the expansion valve assembly.

4. The multi-split air conditioning system according to claim 1, wherein, The adjustment unit includes: The first switching assembly includes: a gas solenoid valve, one end of which is connected to the outlet of the compressor, and the other end of which is connected to the first interface. The gas solenoid valve is used to control the on / off state between the outlet of the compressor and the refrigerant circulation loop. A second switch assembly is disposed on the first water tank branch. One end of the second switch assembly is connected to the outlet of the compressor, and the other end of the second switch assembly is connected to one end of the water tank heat exchanger. The second switch assembly is used to control the on / off state between the first water tank branch and the refrigerant circulation loop. The first throttling control component has one end connected to the refrigerant circulation loop and the other end connected to the compressor inlet and the fourth interface. The first throttling control component is used to allow the refrigerant in the outdoor heat exchanger and / or indoor heat exchanger group to flow back or not flow back to the compressor by its own on / off state. A flow regulating component is installed on the path of the second water tank. One end of the flow regulating component is connected to the other end of the water tank heat exchanger, and the other end of the flow regulating component is connected to one end of the expansion valve assembly and one end of the outdoor electronic expansion valve. The flow regulating component is used to regulate the flow rate of the refrigerant flowing out of the water tank heat exchanger. The third switching assembly includes: a liquid solenoid valve, one end of which is connected to one end of the outdoor electronic expansion valve, and the other end of which is connected to one end of the expansion valve assembly and one end of the flow regulating assembly. The liquid solenoid valve is used to control the on / off state between the indoor heat exchanger assembly and the outdoor heat exchanger, and to control the on / off state between the second water tank branch and the outdoor heat exchanger.

5. The multi-split air conditioning system according to claim 4, wherein, The adjustment unit further includes: The second throttling control component has one end connected to the first water tank branch and the other end connected to the compressor inlet and the fourth interface. The second throttling control component is used to control the refrigerant in the water tank branch to either flow back to or not flow back to the compressor by controlling its on / off state.

6. The multi-split air conditioning system according to claim 4 or 5, wherein, The second switching assembly includes: A second four-way valve is provided on the branch of the first water tank, wherein the fifth port of the second four-way valve is connected to the outlet of the compressor, the sixth port of the second four-way valve is closed, the seventh port of the second four-way valve is connected to one end of the heat exchanger of the water tank, and the eighth port of the second four-way valve is connected to the inlet of the compressor.

7. The multi-split air conditioning system according to claim 6, wherein, The second switching assembly further includes: A first solenoid valve is provided on the first water tank branch, wherein one end of the first solenoid valve is connected to the outlet of the compressor, and the other end of the first solenoid valve is connected to the fifth interface of the second four-way valve.

8. The multi-split air conditioning system according to claim 7, wherein, The first throttling control component includes: a first capillary tube and a second solenoid valve connected in series, wherein one end of the first capillary tube is connected to the other end of the gas solenoid valve and the first interface, the other end of the first capillary tube is connected to one end of the second solenoid valve, and the other end of the second solenoid valve is connected to the inlet of the compressor and the fourth interface.

9. The multi-split air conditioning system according to claim 8, wherein, The flow regulation component includes: a second electronic expansion valve disposed on the second water tank branch, wherein one end of the second electronic expansion valve is connected to the other end of the water tank heat exchanger, and the other end of the second electronic expansion valve is connected to one end of the expansion valve assembly and one end of the outdoor electronic expansion valve.

10. The multi-split air conditioning system according to claim 9, wherein, The second throttling control component includes a second capillary tube and a third solenoid valve connected in series. One end of the second capillary tube is connected to the first water tank branch, and the other end of the second capillary tube is connected to one end of the third solenoid valve. The other end of the third solenoid valve is connected to the inlet of the compressor and the fourth interface.

11. The multi-split air conditioning system according to claim 10, wherein, When the controller is configured to operate the multi-split air conditioning system in defrost mode in response to a first control command, the controller is configured to: When the regulating unit does not include the second throttling control component and the second switching component does not include the first solenoid valve, the first and second interfaces of the first four-way valve are controlled to be connected, and the third and fourth interfaces of the first four-way valve are controlled to be connected; the outdoor electronic expansion valve is controlled to be fully open; multiple first electronic expansion valves are controlled to be closed; the gas solenoid valve is controlled to be fully open; the liquid solenoid valve is controlled to be fully open; the second electronic expansion valve is controlled to be opened; the second solenoid valve is controlled to be closed; and the fifth and sixth interfaces of the second four-way valve are controlled to be connected, and the seventh and eighth interfaces of the second four-way valve are controlled to be connected. When the regulating unit includes the second throttling control component and the second switching component includes the first solenoid valve, the first and second interfaces of the first four-way valve are controlled to be connected, and the third and fourth interfaces of the first four-way valve are controlled to be connected; the outdoor electronic expansion valve is controlled to be fully open; multiple first electronic expansion valves are controlled to be closed; the gas solenoid valve is controlled to be fully open; the liquid solenoid valve is controlled to be fully open; the second electronic expansion valve is controlled to be opened; the second solenoid valve is controlled to be closed; the fifth and sixth interfaces of the second four-way valve are controlled to be connected, and the seventh and eighth interfaces of the second four-way valve are controlled to be connected, and the first solenoid valve is controlled to be closed, and the third solenoid valve is controlled to be closed.

12. The multi-split air conditioning system according to claim 1, wherein, The multi-split air conditioning system also includes a subcooling device. The subcooling device is connected to the second water tank branch line. One end of the subcooling device is connected to the other end of the water tank heat exchanger, and the other end of the subcooling device is connected to one end of the expansion valve assembly and one end of the outdoor electronic expansion valve. The subcooling device is used to exchange heat with the refrigerant in the second water tank branch line to heat the water entering the water tank; or, The subcooling device is connected to the refrigerant circulation loop. One end of the subcooling device is connected to one end of the expansion valve assembly and the other end of the water tank heat exchanger. The other end of the subcooling device is connected to one end of the outdoor electronic expansion valve. The subcooling device is used to exchange heat with the refrigerant in the refrigerant circulation loop to heat the water entering the water tank.

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