Air conditioning system

Abstract

The invention discloses an air conditioning system, belongs to the technical field of air conditioners, and aims to solve the technical problem that the indoor temperature cannot be adjusted when the air conditioning system is in a dehumidification mode. The air conditioning system comprises an outdoor unit, an indoor unit and a control box, and a bypass pipe, a first control valve and a second control valve are arranged in the control box, so that when a first outdoor heat exchanger in the indoor unit performs dehumidification, a second outdoor heat exchanger adjusts the temperature of air. When the indoor unit is in the heating and dehumidifying mode, the temperature heating degree of the second indoor heat exchanger is larger than the temperature reducing degree of the first indoor heat exchanger, the overall temperature of indoor air is increased, and therefore heating is achieved while dehumidifying is conducted. When the indoor unit is in the refrigeration and dehumidification mode, the temperature reduction degree of the first indoor heat exchanger is larger than the temperature heating degree of the second indoor heat exchanger, the overall temperature of indoor air is reduced, and therefore refrigeration is achieved while dehumidification is conducted.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and more particularly to an air conditioning system. Background Technology

[0002] During the rainy season, rooms often become damp due to the rainy weather, which not only affects the comfort of living but may also pose a potential threat to health. It is necessary to dehumidify the room air to reduce indoor humidity and improve the comfort of users.

[0003] In related technologies, air conditioning systems have a dehumidification mode. In dehumidification mode, the indoor temperature cannot be adjusted. Setting the air conditioning system to dehumidification mode can reduce the humidity of the indoor air, but at the same time, it will cause the indoor temperature to drop significantly, which will exacerbate the user's discomfort. Summary of the Invention

[0004] This application provides an air conditioning system that solves the technical problem that air conditioning systems cannot adjust indoor temperature in dehumidification mode.

[0005] This application provides an air conditioning system, including:

[0006] The outdoor unit includes the refrigerant outlet pipe and the refrigerant return pipe;

[0007] The control box includes a control valve assembly, a bypass pipe, a first control valve, and a second control valve; the control valve assembly includes a first box four-way valve and a second box four-way valve.

[0008] The third valve port of the first box four-way valve and the third valve port of the second box four-way valve are respectively connected to the refrigerant outlet pipe, and the first valve port of the first box four-way valve and the first valve port of the second box four-way valve are respectively connected to the refrigerant return pipe.

[0009] The two ends of the bypass pipe are connected to the refrigerant outlet pipe and the refrigerant return pipe, respectively;

[0010] The first control valve and the second control valve are respectively located on the bypass pipe, and the first control valve is closer to the refrigerant outlet pipe than the second control valve;

[0011] The indoor unit includes a first indoor heat exchanger, a second indoor heat exchanger, a first indoor throttling device, and a second indoor throttling device;

[0012] One end of the heat exchanger in the first chamber is connected to the second valve port of the four-way valve in the second box, and the other end is connected to the part of the bypass pipe located between the first control valve and the second control valve through the throttling element in the first chamber.

[0013] One end of the second indoor heat exchanger is connected to the second valve port of the first box four-way valve, and the other end is connected to the part of the bypass pipe located between the first control valve and the second control valve through the second indoor throttling element;

[0014] The indoor unit has both heating and dehumidification modes and cooling and dehumidification modes;

[0015] When the indoor unit is in heating dehumidification mode or cooling dehumidification mode, the second valve port of the first box four-way valve is connected to the third valve port of the first box four-way valve, and the second valve port of the second box four-way valve is connected to the first valve port of the second box four-way valve.

[0016] When the indoor unit is in heating and dehumidification mode, the first control valve is closed and the second control valve is open;

[0017] When the indoor unit is in cooling and dehumidification mode, the first control valve is open and the second control valve is closed.

[0018] In the air conditioning system of this application embodiment, when the indoor unit is in heating and dehumidification mode, the indoor temperature will decrease during the evaporation and heat absorption process of the first indoor heat exchanger. Since most of the refrigerant condenses and releases heat at the second indoor heat exchanger, while a small portion of the refrigerant evaporates and absorbs heat at the first indoor heat exchanger, the degree of heating by the second indoor heat exchanger is greater than the degree of temperature reduction by the first indoor heat exchanger in heating and dehumidification mode. The overall temperature of the indoor air is increased, thereby achieving heating while dehumidifying.

[0019] When the indoor unit is in cooling / dehumidifying mode, most of the refrigerant evaporates and absorbs heat in the first indoor heat exchanger to dehumidify the indoor air. During this process, the indoor temperature decreases. A small portion of the refrigerant condenses and releases heat in the second indoor heat exchanger to heat the indoor air. Because most of the refrigerant evaporates and absorbs heat in the first heat exchanger, while a small portion condenses and releases heat in the second, the temperature decrease caused by the first heat exchanger is greater than the temperature increase caused by the second heat exchanger. Therefore, the overall indoor air temperature decreases, achieving cooling while dehumidifying.

[0020] In some embodiments of this application, the indoor unit also has a heating mode and a cooling mode;

[0021] When the indoor unit is in heating mode, the second valve port of the first four-way valve is connected to the third valve port of the first four-way valve, and the second valve port of the second four-way valve is connected to the third valve port of the second four-way valve. The first control valve is closed and the second control valve is open.

[0022] When the indoor unit is in cooling mode, the second valve port of the first four-way valve is connected to the first valve port of the first four-way valve, and the second valve port of the second four-way valve is connected to the first valve port of the second four-way valve. The first control valve is open and the second control valve is closed.

[0023] With this configuration, when the indoor unit is in heating mode, the refrigerant condenses and releases heat at both the first and second indoor heat exchangers, simultaneously raising the temperature of the indoor environment and increasing the rate of temperature increase. When the indoor unit is in cooling mode, the refrigerant evaporates and absorbs heat at both the first and second indoor heat exchangers, simultaneously lowering the temperature of the indoor environment and increasing the rate of temperature decrease.

[0024] In some embodiments of this application, the outdoor unit further includes a compressor, an outdoor heat exchanger, an outdoor throttling device, a first outdoor four-way valve, and a second outdoor four-way valve;

[0025] The compressor's inlet and outlet are connected to the first and third ports of the first outdoor four-way valve, respectively.

[0026] One end of the outdoor heat exchanger is connected to the fourth valve port of the first outdoor four-way valve, and the other end is connected to the first valve port of the second outdoor four-way valve through an outdoor throttling device.

[0027] The third valve port of the second outdoor four-way valve is connected to the second valve port of the first outdoor four-way valve. The second valve port of the second outdoor four-way valve is connected to the refrigerant outlet pipe. The fourth valve port of the second outdoor four-way valve is connected to the refrigerant return pipe.

[0028] With this setup, the outdoor unit can be configured to operate in either evaporator or condenser mode by operating the first and second outdoor four-way valves.

[0029] In some embodiments of this application, the air conditioning system further includes a controller, which is electrically connected to a first outdoor four-way valve, a second outdoor four-way valve, a first box four-way valve, a second box four-way valve, a first control valve, and a second control valve, respectively; the controller is configured to:

[0030] Obtain the operating mode of the indoor unit, and calculate the heating demand Qh, cooling demand Qc, and dehumidification demand Qd of the indoor unit based on the operating mode;

[0031] When Qc+Qd>Qh, the third valve port of the first outdoor four-way valve is connected to the fourth valve port of the first outdoor four-way valve, the third valve port of the second outdoor four-way valve is connected to the fourth valve port of the second outdoor four-way valve, the first control valve is opened, and the second control valve is closed.

[0032] When Qc+Qd≤Qh, the second valve port of the first outdoor four-way valve is connected to the third valve port of the first outdoor four-way valve, the second valve port of the second outdoor four-way valve is connected to the third valve port of the second outdoor four-way valve, the first control valve is closed, and the second control valve is opened.

[0033] The indoor unit's operating modes include: heating mode, cooling mode, heating and dehumidification mode, and cooling and dehumidification mode.

[0034] With this setting, when Qc+Qd>Qh, it indicates that the overall cooling demand of the indoor unit is greater than the heating demand, and the controller controls the outdoor unit to operate in condenser mode. When Qc+Qd≤Qh, it indicates that the overall heating demand of the indoor unit is greater than or equal to the cooling demand, and the controller controls the outdoor unit to operate in evaporator mode.

[0035] In some embodiments of this application, when the indoor unit is in heating mode, Qh is the rated heating capacity of the indoor unit, and Qc and Qd are both zero.

[0036] When the indoor unit is in cooling mode, Qc is the rated cooling capacity of the indoor unit, and Qh and Qd are both zero.

[0037] When the indoor unit is in heating dehumidification mode or cooling dehumidification mode, Qd is the rated dehumidification capacity of the indoor unit.

[0038] With this setup, when the indoor unit is in heating / dehumidification or cooling / dehumidification mode, both Qh and Qc are 0, and the indoor unit only has Qd, which is the rated dehumidification capacity of the indoor unit. The rated dehumidification capacity is the total heat removed from the room per unit time when the indoor unit is operating in heating / dehumidification or cooling / dehumidification mode. When the indoor unit is operating in heating / dehumidification mode, Qd < 0 < Qh, therefore the controller controls the outdoor unit to operate in evaporator mode. When the indoor unit is operating in cooling / dehumidification mode, Qd > 0 and Qd > Qh, therefore the controller controls the outdoor unit to operate in condenser mode.

[0039] In some embodiments of this application, the indoor unit has an air inlet and an air outlet, the first indoor heat exchanger is closer to the air inlet than the second indoor heat exchanger, and the second indoor heat exchanger is closer to the air outlet than the first indoor heat exchanger.

[0040] The indoor unit also includes a first temperature detector, a second temperature detector, and a third temperature detector, which are electrically connected to the controller respectively;

[0041] The first temperature detector is located between the air inlet and the first indoor heat exchanger, the second temperature detector is located between the first indoor heat exchanger and the second indoor heat exchanger, and the third temperature detector is located between the second indoor heat exchanger and the air outlet.

[0042] With this setup, the first temperature detector is used to detect the inlet air temperature T1 of the first indoor heat exchanger. The second temperature detector is used to detect the inlet air temperature T2 of the second indoor heat exchanger. The third temperature detector is used to detect the outlet air temperature T3 of the second indoor heat exchanger.

[0043] In some embodiments of this application, when the indoor unit is in heating mode, the indoor unit only has Qh, and Qh = HPh. (T3-T1);

[0044] When the indoor unit is in cooling mode, the indoor unit only has Qc, and Qc = HPc. (T1-T3);

[0045] When the indoor unit is in heating / dehumidification or cooling / dehumidification mode, Qh=0.5 HPh (T3-T2), Qd=0.5 HPd (T1-T2);

[0046] Where HPh is the rated heating capacity of the indoor unit, HPc is the rated cooling capacity of the indoor unit, HPd is the rated dehumidification capacity of the indoor unit, T1 is the inlet air temperature of the first indoor heat exchanger, T2 is the inlet air temperature of the second indoor heat exchanger, and T3 is the outlet air temperature of the second indoor heat exchanger.

[0047] With this setup, the controller can switch the outdoor unit's operating mode (evaporator mode or condenser mode) based on the real-time temperatures of T1, T2, and T3, combined with the indoor unit's operating mode, to meet the indoor temperature and humidity requirements.

[0048] In some embodiments of this application, the air conditioning system includes multiple indoor units, which are connected in parallel.

[0049] The control box includes multiple control valve groups, which are connected in parallel, and each control valve group corresponds to an indoor unit.

[0050] This configuration allows the refrigerant flow of multiple indoor units to be independent, enabling independent control of each indoor unit.

[0051] In some embodiments of this application, the controller is configured as follows:

[0052] Obtain the operating modes of all indoor units in operation, and calculate the sum of heating demand ΣQh, cooling demand ΣQc, and dehumidification demand ΣQd of all indoor units in operation based on the operating modes.

[0053] When ΣQc+ΣQd>ΣQh, the third valve port of the first outdoor four-way valve is connected to the fourth valve port of the first outdoor four-way valve, the third valve port of the second outdoor four-way valve is connected to the fourth valve port of the second outdoor four-way valve, the first control valve is opened, and the second control valve is closed.

[0054] When ΣQc+ΣQd≤ΣQh, the second valve port of the first outdoor four-way valve is connected to the third valve port of the first outdoor four-way valve, the second valve port of the second outdoor four-way valve is connected to the third valve port of the second outdoor four-way valve, the first control valve is closed, and the second control valve is opened.

[0055] With this configuration, when the overall cooling demand of all indoor units in operation exceeds the heating demand, the controller will control the outdoor unit to operate in condenser mode. Conversely, when the overall heating demand of all indoor units in operation is greater than or equal to the cooling demand, the controller will control the outdoor unit to operate in evaporator mode.

[0056] In some embodiments of this application, the outdoor unit further includes a gas-liquid separator, the inlet of which is connected to the first valve port of the first outdoor four-way valve, and the outlet of which is connected to the air inlet of the compressor.

[0057] With this configuration, the gas-liquid separator separates the liquid refrigerant from the lubricating oil in the return gas and retains it at the bottom, allowing only the gaseous refrigerant to enter the compressor from the outlet of the gas-liquid separator. Attached Figure Description

[0058] To more clearly illustrate the implementation methods in the embodiments of this application or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0059] Figure 1 A schematic diagram of the structure of an air conditioning system according to an embodiment of this application is shown;

[0060] Figure 2 It shows Figure 1 A schematic diagram of the structure of the outdoor unit when it is in evaporator mode;

[0061] Figure 3 It shows Figure 1 A schematic diagram of the structure of the outdoor unit when it is in condenser mode;

[0062] Figure 4 This paper shows a schematic diagram of the structure of the air conditioning system according to an embodiment of the present application when the indoor unit is in heating mode;

[0063] Figure 5 This paper shows a schematic diagram of the structure of the air conditioning system according to an embodiment of the present application when the indoor unit is in cooling mode;

[0064] Figure 6 This illustration shows a schematic diagram of the structure of the air conditioning system according to an embodiment of the present application when the indoor unit is operating in heating and dehumidification mode;

[0065] Figure 7 This illustration shows a schematic diagram of the air conditioning system according to an embodiment of the present application when the indoor unit is operating in cooling and dehumidification mode;

[0066] Figure 8 A schematic diagram of the structure of an air conditioning system according to an embodiment of this application, including multiple indoor units, is shown.

[0067] Figure 9 A schematic diagram of the control flow of an air conditioning system according to an embodiment of this application is shown.

[0068] Explanation of reference numerals in the attached figures:

[0069] 10-Outdoor unit; 101-Compressor; 102-Outdoor heat exchanger; 103-Outdoor throttling device; 104-First outdoor four-way valve; 105-Second outdoor four-way valve; 106-Gas-liquid separator; 107-Refrigerant outlet pipe; 108-Refrigerant return pipe; 109-Outdoor fan;

[0070] 20-Control box; 201-First box four-way valve; 202-Second box four-way valve; 203-Bypass pipe; 204-First control valve; 205-Second control valve;

[0071] 30-Indoor unit; 301-First indoor heat exchanger; 302-Second indoor heat exchanger; 303-First indoor throttling device; 304-Second indoor throttling device; 305-Air inlet; 306-Air outlet; 307-First temperature detector; 308-Second temperature detector; 309-Third temperature detector. Detailed Implementation

[0072] To make the objectives and implementation methods of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the exemplary embodiments described are only some embodiments of this application, and not all embodiments.

[0073] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0074] The terms "first," "second," "third," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar or related objects or entities, and do not necessarily imply a specific order or sequence, unless otherwise specified. It should be understood that such terms are interchangeable where appropriate.

[0075] The terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device that includes a range of components is not necessarily limited to all of the components that are clearly listed, but may include other components that are not clearly listed or that are inherent to such product or device.

[0076] In view of the problem that air conditioning systems in related technologies cannot adjust the indoor temperature in dehumidification mode, this application provides an air conditioning system that, by setting a bypass pipe, a first control valve and a second control valve in the control box, enables the second outdoor heat exchanger in the indoor unit to adjust the air temperature while the first outdoor heat exchanger in the indoor unit is dehumidifying, thereby achieving heating dehumidification or cooling dehumidification, so that the air conditioning system can also adjust the indoor temperature while dehumidifying.

[0077] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0078] refer to Figure 1 The air conditioning unit provided in this application embodiment includes an outdoor unit 10, a control box 20, and an indoor unit 30.

[0079] The outdoor unit 10 includes an outdoor heat exchanger 102, a refrigerant outlet pipe 107, and a refrigerant return pipe 108 connected by pipes. The outdoor unit 10 can have an evaporator mode and a condenser mode.

[0080] refer to Figure 2 When the outdoor unit 10 is in evaporator mode, that is, when the outdoor heat exchanger 102 acts as an evaporator, the refrigerant evaporates and absorbs heat at the outdoor heat exchanger 102, changing from a liquid state to a gaseous state. The refrigerant flowing out from the refrigerant outlet pipe 107 is in a gaseous state, and the refrigerant flowing back to the outdoor unit 10 through the refrigerant return pipe 108 can be in a liquid state or a gas-liquid mixture state.

[0081] refer to Figure 3 When the outdoor unit 10 is in condenser mode, that is, when the outdoor heat exchanger 102 acts as a condenser, the refrigerant condenses and releases heat at the outdoor heat exchanger 102, changing from a gaseous state to a liquid state. The refrigerant flowing out from the refrigerant outlet pipe 107 is in a liquid state or a gas-liquid mixture state, while the refrigerant flowing back to the outdoor unit 10 from the refrigerant return pipe 108 is in a gaseous state.

[0082] refer to Figure 1 , Figure 2 and Figure 3 The outdoor unit 10 may also include a compressor 101, an outdoor throttling device 103, a first outdoor four-way valve 104, and a second outdoor four-way valve 105.

[0083] The first outdoor four-way valve 104 may have a first valve port S1, a second valve port C1, a third valve port D1, and a fourth valve port E1.

[0084] The second outdoor four-way valve 105 may have a first valve port S2, a second valve port C2, a third valve port D2, and a fourth valve port E2.

[0085] The air inlet and air outlet of the compressor 101 are respectively connected to the first valve port S1 and the third valve port D1 of the first outdoor four-way valve 104.

[0086] One end of the outdoor heat exchanger 102 is connected to the fourth valve port E1 of the first outdoor four-way valve 104, and the other end of the outdoor heat exchanger 102 is connected to the first valve port S2 of the second outdoor four-way valve 105 through the outdoor throttling device 103.

[0087] The third valve port D2 of the second outdoor four-way valve 105 is connected to the second valve port C1 of the first outdoor four-way valve 104, the second valve port C2 of the second outdoor four-way valve 105 is connected to the refrigerant outlet pipe 107, and the fourth valve port E2 of the second outdoor four-way valve 105 is connected to the refrigerant return pipe 108.

[0088] refer to Figure 1 The outdoor unit 10 also includes a gas-liquid separator 106. The inlet of the gas-liquid separator 106 is connected to the first valve port S1 of the first outdoor four-way valve 104, and the outlet of the gas-liquid separator 106 is connected to the air inlet of the compressor 101. The gas-liquid separator 106 separates the liquid refrigerant and lubricating oil in the return gas and retains them at the bottom, allowing only the gaseous refrigerant to enter the compressor 101 from the outlet of the gas-liquid separator 106.

[0089] refer to Figure 1 The outdoor unit 10 also includes an outdoor fan 109, which is used to accelerate the heat exchange rate between the outdoor heat exchanger 102 and the outdoor air.

[0090] The outdoor unit 10 can be switched to either evaporator mode or condenser mode by the operation of the first outdoor four-way valve 104 and the second outdoor four-way valve 105.

[0091] refer to Figure 2 When the outdoor unit 10 is in evaporator mode, the outdoor heat exchanger 102 acts as the evaporator. The second valve port C1 of the first outdoor four-way valve 104 is connected to the third valve port D1 of the first outdoor four-way valve 104, and the second valve port C2 of the second outdoor four-way valve 105 is connected to the third valve port D2 of the second outdoor four-way valve 105. The compressor 101 compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. The high-temperature, high-pressure gaseous refrigerant flows sequentially through the third valve port D1 of the first outdoor four-way valve 104, the second valve port C1 of the first outdoor four-way valve 104, the third valve port D2 of the second outdoor four-way valve 105, and the second valve port C2 of the second outdoor four-way valve 105 to the refrigerant outlet pipe 107. Therefore, the refrigerant at the refrigerant outlet pipe 107 is a high-temperature, high-pressure gaseous refrigerant.

[0092] The high-temperature, high-pressure gaseous refrigerant in the refrigerant outlet pipe 107 flows to the indoor unit 30. At the indoor unit 30, at least a portion of the high-temperature, high-pressure gaseous refrigerant condenses and releases heat, becoming a normal-temperature, high-pressure liquid refrigerant. This liquid refrigerant then flows back to the outdoor unit 10 via the refrigerant return pipe 108, and sequentially through the fourth port E2 and the first port S2 of the second outdoor four-way valve 105 to the outdoor throttling device 103. After being throttled and depressurized at the outdoor throttling device 103, it becomes a low-temperature, low-pressure liquid refrigerant. This low-temperature, low-pressure liquid refrigerant evaporates and absorbs heat at the outdoor heat exchanger 102, becoming a low-temperature, low-pressure gaseous refrigerant. The low-temperature, low-pressure gaseous refrigerant is then drawn back into the compressor 10110, compressed by the compressor 101, and continues to circulate, causing the refrigerant to continuously condense and release heat at the indoor unit 30, thereby increasing the temperature of the indoor environment where the indoor unit 30 is located.

[0093] refer to Figure 3 When the outdoor unit 10 is in condenser mode, the outdoor heat exchanger 102 acts as a condenser. The third valve port D1 of the first outdoor four-way valve 104 is connected to the fourth valve port E1 of the first outdoor four-way valve 104, and the third valve port D2 of the second outdoor four-way valve 105 is connected to the fourth valve port E2 of the second outdoor four-way valve 105. The compressor 101 compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. The high-temperature, high-pressure gaseous refrigerant flows sequentially through the third valve port D1 and the fourth valve port E1 of the first outdoor four-way valve 104 to the outdoor heat exchanger 102. In the outdoor heat exchanger 102, at least part of the high-temperature, high-pressure gaseous refrigerant condenses and releases heat, becoming a normal-temperature, high-pressure liquid refrigerant. The normal-temperature, high-pressure liquid refrigerant is throttled and depressurized by the outdoor throttling device 103, becoming a low-temperature, low-pressure liquid refrigerant. The low-temperature, low-pressure liquid refrigerant flows sequentially through the first valve port S2 and the second valve port C2 of the second outdoor four-way valve 105 to the refrigerant outlet pipe 107. Therefore, the refrigerant at the refrigerant outlet pipe 107 is either a low-temperature, low-pressure liquid refrigerant or a gas-liquid mixture.

[0094] The low-temperature, low-pressure liquid refrigerant in the refrigerant outlet pipe 107 flows to the indoor unit 30, where it evaporates and absorbs heat, becoming a low-temperature, low-pressure gaseous refrigerant. It then flows back to the outdoor unit 10 through the refrigerant return pipe 108, and is subsequently drawn back into the compressor 10110 through the fourth valve port E2 of the second outdoor four-way valve 105, the third valve port D2 of the second outdoor four-way valve 105, the second valve port C1 of the first outdoor four-way valve 104, and the first valve port S1 of the first outdoor four-way valve 104. After being compressed by the compressor 101, it continues to circulate, causing the refrigerant to continuously evaporate and absorb heat at the indoor unit 30, thereby reducing the temperature of the indoor environment where the indoor unit 30 is located.

[0095] refer to Figure 1 The control box 20 may include a control valve group, a bypass pipe 203, a first control valve 204 and a second control valve 205.

[0096] The control valve assembly may include a first four-way valve 201 and a second four-way valve 202.

[0097] The first four-way valve 201 may have a first valve port S3, a second valve port C3, a third valve port D3, and a fourth valve port E3.

[0098] The second four-way valve 202 may have a first valve port S4, a second valve port C4, a third valve port D4, and a fourth valve port E4.

[0099] The third valve port D3 of the first box four-way valve 201 and the third valve port D4 of the second box four-way valve 202 are respectively connected to the refrigerant outlet pipe 107, and the first valve port S3 of the first box four-way valve 201 and the first valve port S4 of the second box four-way valve 202 are respectively connected to the refrigerant return pipe 108.

[0100] The two ends of the bypass pipe 203 are connected to the refrigerant outlet pipe 107 and the refrigerant return pipe 108, respectively.

[0101] The first control valve 204 and the second control valve 205 are respectively installed on the bypass pipe 203, and the first control valve 204 is closer to the refrigerant outlet pipe 107 than the second control valve 205.

[0102] refer to Figure 1 The indoor unit 30 may include a first indoor heat exchanger 301, a second indoor heat exchanger 302, a first indoor throttling device 303, and a second indoor throttling device 304.

[0103] One end of the first indoor heat exchanger 301 is connected to the second valve port C4 of the second box four-way valve 202, and the other end is connected to the part of the bypass pipe 203 located between the first control valve 204 and the second control valve 205 through the first indoor throttling element 303.

[0104] One end of the second indoor heat exchanger 302 is connected to the second valve port C3 of the first box four-way valve 201, and the other end is connected to the part of the bypass pipe 203 located between the first control valve 204 and the second control valve 205 through the second indoor throttling element 304.

[0105] The indoor unit 30 has both heating and cooling modes.

[0106] refer to Figure 4 When the indoor unit 30 is in heating mode, the second valve port C3 of the first four-way valve 201 is connected to the third valve port D3 of the first four-way valve 201, the second valve port C4 of the second four-way valve 202 is connected to the third valve port D4 of the second four-way valve 202, the first control valve 204 is closed, and the second control valve 205 is open.

[0107] When the indoor unit 30 is in heating mode, the outdoor unit 10 is in evaporator mode. The refrigerant at the refrigerant outlet pipe 107 is a high-temperature and high-pressure gaseous refrigerant. Part of the high-temperature and high-pressure gaseous refrigerant flows sequentially through the third valve port D3 and the second valve port C3 of the first box four-way valve 201 to the second indoor heat exchanger 302. After condensing and releasing heat at the second indoor heat exchanger 302, it becomes a normal-temperature and high-pressure liquid refrigerant. After the normal-temperature and high-pressure liquid refrigerant is throttled and depressurized by the second indoor throttling device 304, it becomes a low-temperature and low-pressure liquid refrigerant. The low-temperature and low-pressure liquid refrigerant then flows through the second control valve 205 to the refrigerant return pipe 108, and then flows back to the outdoor unit 10 through the refrigerant return pipe 108.

[0108] Another portion of the high-temperature, high-pressure gaseous refrigerant flowing out of the refrigerant outlet pipe 107 flows sequentially through the third valve port D4 and the second valve port C4 of the second four-way valve 202 to the first indoor heat exchanger 301. After condensing and releasing heat at the first indoor heat exchanger 301, it becomes a room-temperature, high-pressure liquid refrigerant. After being throttled and depressurized by the first indoor throttling device 303, the room-temperature, high-pressure liquid refrigerant becomes a low-temperature, low-pressure liquid refrigerant. The low-temperature, low-pressure liquid refrigerant then flows back to the outdoor unit 10 through the refrigerant return pipe 108.

[0109] The refrigerant condenses and releases heat at the first indoor heat exchanger 301 and the second indoor heat exchanger 302, thereby simultaneously increasing the temperature of the indoor environment where the indoor unit 30 is located and increasing the rate of increase in indoor temperature.

[0110] refer to Figure 5 When the indoor unit 30 is in cooling mode, the second valve port C3 of the first four-way valve 201 is connected to the first valve port S3 of the first four-way valve 201, the second valve port C4 of the second four-way valve 202 is connected to the first valve port S4 of the second four-way valve 202, the first control valve 204 is open, and the second control valve 205 is closed.

[0111] When the indoor unit 30 is in cooling mode, the outdoor unit 10 is in condenser mode. The low-temperature, low-pressure liquid refrigerant at the refrigerant outlet pipe 107 flows through the first control valve 204, and a portion of it flows to the second indoor throttling device 304. After being throttled and depressurized by the second indoor throttling device 304, it becomes a low-temperature, low-pressure liquid refrigerant. The low-temperature, low-pressure liquid refrigerant evaporates and absorbs heat at the second indoor heat exchanger 302, becoming a low-temperature, low-pressure gaseous refrigerant. The low-temperature, low-pressure gaseous refrigerant returns to the refrigerant return pipe 108 through the second valve port C3 and the first valve port S3 of the first four-way valve 201, and then flows back to the outdoor unit 10.

[0112] Another portion of the low-temperature, low-pressure liquid refrigerant flowing through the first control valve 204 flows to the first indoor throttling device 303. After being throttled and depressurized by the first indoor throttling device 303, it becomes a low-temperature, low-pressure liquid refrigerant. The low-temperature, low-pressure liquid refrigerant evaporates and absorbs heat at the first indoor heat exchanger 301, becoming a low-temperature, low-pressure gaseous refrigerant. The low-temperature, low-pressure gaseous refrigerant returns to the refrigerant return pipe 108 through the second valve port C4 and the first valve port S4 of the second box four-way valve 202, and then flows back to the outdoor unit 10.

[0113] The refrigerant evaporates and absorbs heat at the first indoor heat exchanger 301 and the second indoor heat exchanger 302, thereby simultaneously reducing the temperature of the indoor environment where the indoor unit 30 is located and increasing the rate of temperature reduction.

[0114] The air conditioning system provided in this application embodiment also includes an indoor unit 30 with a heating dehumidification mode and a cooling dehumidification mode.

[0115] refer to Figure 6 When the indoor unit 30 is in heating and dehumidification mode, the second valve port C3 of the first box four-way valve 201 is connected to the third valve port D3 of the first box four-way valve 201, the second valve port C4 of the second box four-way valve 202 is connected to the first valve port S4 of the second box four-way valve 202, the first control valve 204 is closed, and the second control valve 205 is opened.

[0116] The high-temperature, high-pressure gaseous refrigerant at the refrigerant outlet pipe 107 flows sequentially through the third valve port D3 and the second valve port C3 of the first box four-way valve 201 to the second indoor heat exchanger 302. After condensing and releasing heat at the second indoor heat exchanger 302, it becomes a room-temperature, high-pressure liquid refrigerant. After being throttled and depressurized by the second indoor throttling device 304, the room-temperature, high-pressure liquid refrigerant becomes a low-temperature, low-pressure liquid refrigerant. Part of the low-temperature, low-pressure liquid refrigerant flows to the second control valve 205 and then to the refrigerant return pipe 108, from which it flows back to the outdoor unit 10. The other part of the low-temperature, low-pressure liquid refrigerant flows to the first indoor throttling device 303 and the first indoor heat exchanger 301, where it evaporates and absorbs heat to become a low-temperature, low-pressure gaseous refrigerant. The low-temperature, low-pressure gaseous refrigerant then flows back to the refrigerant return pipe 108 through the second valve port C4 and the first valve port S4 of the second four-way valve 202, and then flows back to the outdoor unit 10.

[0117] In other words, when the indoor unit 30 is in heating and dehumidification mode, the first indoor heat exchanger 301 evaporates and absorbs heat to dehumidify the indoor air; the second indoor heat exchanger 302 condenses and releases heat to heat the indoor air and increase the indoor temperature. The first indoor heat exchanger 301 and the second indoor heat exchanger 302 work together to achieve the effect of simultaneously heating the indoor air while dehumidifying it.

[0118] During the evaporation and heat absorption process of the first indoor heat exchanger 301, the indoor temperature will decrease. Since most of the refrigerant condenses and releases heat at the second indoor heat exchanger 302, while a small portion of the refrigerant evaporates and absorbs heat at the first indoor heat exchanger 301, the degree of heating by the second indoor heat exchanger 302 is greater than the degree of temperature reduction by the first indoor heat exchanger 301 during the heating and dehumidification mode. As a result, the overall temperature of the indoor air increases, thus achieving heating while dehumidifying.

[0119] refer to Figure 7 When the indoor unit 30 is in cooling and dehumidification mode, the second valve port C3 of the first box four-way valve 201 is connected to the third valve port D3 of the first box four-way valve 201, the second valve port C4 of the second box four-way valve 202 is connected to the first valve port S4 of the second box four-way valve 202, the first control valve 204 is opened, and the second control valve 205 is closed.

[0120] When the indoor unit 30 is in cooling and dehumidification mode, the refrigerant partially condenses at the outdoor heat exchanger 102. The refrigerant at the refrigerant outlet pipe 107 is a low-temperature, low-pressure gas-liquid mixture. A portion of the low-temperature, low-pressure gas-liquid mixture flows to the first four-way valve 201, and then flows through the third valve port D3 and the second valve port C3 of the first four-way valve 201 to the second indoor heat exchanger 302. At the second indoor heat exchanger 302, the liquid refrigerant in the gas-liquid mixture condenses and releases heat, becoming a room-temperature, high-pressure liquid refrigerant. After being throttled and depressurized by the second indoor throttling device 304, the room-temperature, high-pressure liquid refrigerant becomes a low-temperature, low-pressure liquid refrigerant. Another portion of the gas-liquid mixed refrigerant at the refrigerant outlet pipe 107 flows to the first control valve 204, where it mixes with the low-temperature, low-pressure liquid refrigerant flowing out from the second indoor throttling device 304. After mixing, it flows from the first control valve 204 to the first indoor heat exchanger 301, where it evaporates and absorbs heat to become a low-temperature, low-pressure gaseous refrigerant. The low-temperature, low-pressure gaseous refrigerant then returns to the refrigerant return pipe 108 via the second valve port C4 and the first valve port S4 of the second four-way valve 202, and then flows back to the outdoor unit 10.

[0121] In other words, when the indoor unit 30 is in cooling / dehumidifying mode, most of the refrigerant evaporates and absorbs heat in the first indoor heat exchanger 301 to dehumidify the indoor air; during this process, the indoor temperature decreases. A small portion of the refrigerant condenses and releases heat in the second indoor heat exchanger 302 to heat the indoor air. Because most of the refrigerant evaporates and absorbs heat in the first indoor heat exchanger 301, while a small portion condenses and releases heat in the second indoor heat exchanger 302, the degree to which the first indoor heat exchanger 301 lowers the temperature is greater than the degree to which the second indoor heat exchanger 302 heats the temperature. Therefore, the overall indoor air temperature decreases, achieving cooling while dehumidifying.

[0122] The air conditioning system in this embodiment of the application also includes a controller, which is electrically connected to the first outdoor four-way valve 104, the second outdoor four-way valve 105, the first box four-way valve 201, the second box four-way valve 202, the first control valve 204, and the second control valve 205.

[0123] The controller is configured as follows:

[0124] Obtain the operating mode of the indoor unit 30, and calculate the heating demand Qh, cooling demand Qc and dehumidification demand Qd of the indoor unit 30 based on the operating mode;

[0125] When Qc+Qd>Qh, the third valve port D1 of the first outdoor four-way valve 104 is connected to the fourth valve port E1 of the first outdoor four-way valve 104, the third valve port D2 of the second outdoor four-way valve 105 is connected to the fourth valve port E2 of the second outdoor four-way valve 105, the first control valve 204 is opened, and the second control valve 205 is closed.

[0126] When Qc+Qd≤Qh, the second valve port C1 of the first outdoor four-way valve 104 is connected to the third valve port D1 of the first outdoor four-way valve 104, the second valve port C2 of the second outdoor four-way valve 105 is connected to the third valve port D2 of the second outdoor four-way valve 105, the first control valve 204 is closed, and the second control valve 205 is opened.

[0127] The indoor unit 30 has the following operating modes: heating mode, cooling mode, heating and dehumidification mode, and cooling and dehumidification mode.

[0128] The heating demand Qh can be understood as the amount of heating that indoor unit 30 needs to provide, the cooling demand Qc can be understood as the amount of cooling that indoor unit 30 needs to provide, and the dehumidification demand Qd can be understood as the amount of dehumidification that indoor unit 30 needs to provide.

[0129] When Qc+Qd>Qh, it means that the overall cooling demand of the indoor unit 30 is greater than the heating demand. Therefore, the controller controls the third valve port D1 of the first outdoor four-way valve 104 to connect with the fourth valve port E1 of the first outdoor four-way valve 104, controls the third valve port D2 of the second outdoor four-way valve 105 to connect with the fourth valve port E2 of the second outdoor four-way valve 105, controls the first control valve 204 to open, and controls the second control valve 205 to close, which means controlling the outdoor unit 10 to run in condenser mode.

[0130] When Qc+Qd≤Qh, it means that the overall heating demand of the indoor unit 30 is greater than or equal to the cooling demand. Therefore, the controller controls the second valve port C1 of the first outdoor four-way valve 104 to connect with the third valve port D1 of the first outdoor four-way valve 104, controls the second valve port C2 of the second outdoor four-way valve 105 to connect with the third valve port D2 of the second outdoor four-way valve 105, controls the first control valve 204 to close, and controls the second control valve 205 to open, which means controlling the outdoor unit 10 to run in evaporator mode.

[0131] An air conditioning system may include one or more indoor units 30.

[0132] In some possible implementations of this application, taking an indoor unit 30 as an example, when the indoor unit 30 is in heating mode, both Qc and Qd of the indoor unit 30 are 0, and the indoor unit 30 only has Qh, which can be the rated heat capacity of the indoor unit 30. The rated heat capacity is the total amount of heat input into the room per unit time when the indoor unit 30 is in heating mode. Qh > 0, Qh > Qc + Qd, therefore the controller controls the outdoor unit 10 to operate in evaporator mode.

[0133] When indoor unit 30 is in cooling mode, both Qh and Qd of indoor unit 30 are 0. Indoor unit 30 only has Qc, and Qc is the rated cooling capacity of indoor unit 30, which is the total amount of heat removed from the room per unit time when indoor unit 30 is in cooling mode. Qc > 0, Qc + Qd > Qh, therefore the controller controls outdoor unit 10 to operate in condenser mode.

[0134] When indoor unit 30 is in heating / dehumidification or cooling / dehumidification mode, both Qh and Qc of indoor unit 30 are 0. Indoor unit 30 only has Qd, which is the rated dehumidification capacity of indoor unit 30. The rated dehumidification capacity is the total amount of heat removed from the room per unit time when indoor unit 30 is running in heating / dehumidification or cooling / dehumidification mode. When indoor unit 30 is running in heating / dehumidification mode, Qd < 0 < Qh, therefore the controller controls outdoor unit 10 to run in evaporator mode. When indoor unit 30 is running cooling / dehumidification mode, Qd > 0 and Qd > Qh, therefore the controller controls outdoor unit 10 to run in condenser mode.

[0135] The air conditioning system of this application embodiment refers to... Figure 1 The indoor unit 30 may have an air inlet 305 and an air outlet 306. The first indoor heat exchanger 301 is closer to the air inlet 305 than the second indoor heat exchanger 302, and the second indoor heat exchanger 302 is closer to the air outlet 306 than the first indoor heat exchanger 301.

[0136] refer to Figure 1 The indoor unit 30 also includes a first temperature detector 307, a second temperature detector 308 and a third temperature detector 309, which are electrically connected to the controller respectively.

[0137] The first temperature detector 307 is located between the air inlet 305 and the first indoor heat exchanger 301 to detect the air inlet temperature T1 of the first indoor heat exchanger 301.

[0138] The second temperature detector 308 is disposed between the first indoor heat exchanger 301 and the second indoor heat exchanger 302 to detect the inlet air temperature T2 of the second indoor heat exchanger 302.

[0139] The third temperature detector 309 is located between the second indoor heat exchanger 302 and the air outlet 306 to detect the air outlet temperature T3 of the second indoor heat exchanger 302.

[0140] In some other possible implementations of the embodiments of this application, taking an indoor unit 30 as an example, when the indoor unit 30 is in heating mode, the indoor unit 30 only has Qh, and Qh=HPh (T3-T1). Among them, HPh is the rated heating capacity of indoor unit 30, which is the total amount of heat input into the room per unit time when indoor unit 30 is in heating mode.

[0141] When the indoor unit 30 is in cooling mode, the indoor unit 30 only has Qc, and Qc = HPc. (T1-T3). Among them, HPc is the rated cooling capacity of indoor unit 30, which is the total amount of heat removed from the room per unit time by indoor unit 30 in cooling mode.

[0142] When the indoor unit is in heating / dehumidification or cooling / dehumidification mode, Qh=0.5 HPh (T3-T2), Qd=HPd (T1-T2). Wherein, HPd is the rated dehumidification capacity of the indoor unit 30. The rated dehumidification capacity is the total amount of heat removed from the room by the first indoor heat exchanger 301 per unit time when the indoor unit 30 is running in heating dehumidification mode or cooling dehumidification mode.

[0143] HPh represents the total heat input to the room per unit time by the indoor unit 30 in heating mode. In other words, it's the total heat input to the room per unit time by both the first indoor heat exchanger 301 and the second indoor heat exchanger 302 in heating mode. However, when the indoor unit 30 is in heating / dehumidification or cooling / dehumidification mode, only the second indoor heat exchanger 302 inputs heat to the room; therefore, the heat input by the second indoor heat exchanger 302 is 0.5. HPh.

[0144] In this embodiment of the air conditioning system, the controller can switch the operating mode (evaporator mode or condenser mode) of the outdoor unit 10 according to the real-time temperatures of T1, T2, and T3, combined with the operating mode of the indoor unit 30, so as to meet the indoor temperature and humidity requirements.

[0145] In the implementation of an air conditioning system including multiple indoor units 30, refer to Figure 8 Multiple indoor units 30 are connected in parallel. The control box 20 includes multiple control valve groups, which are connected in parallel and correspond one-to-one with the indoor units 30, so that the refrigerant flow of the multiple indoor units 30 is independent and the independent control of each indoor unit 30 can be achieved.

[0146] refer to Figure 9 The controller is configured as follows:

[0147] Obtain the operating modes of all indoor units 30 that are in operation, and calculate the sum of heating demand ΣQh, cooling demand ΣQc, and dehumidification demand ΣQd of all indoor units 30 that are in operation based on the operating modes.

[0148] When ΣQc + ΣQd > ΣQh, the controller connects the third valve port D1 of the first outdoor four-way valve 104 to the fourth valve port E1 of the first outdoor four-way valve 104, connects the third valve port D2 of the second outdoor four-way valve 105 to the fourth valve port E2 of the second outdoor four-way valve 105, controls the first control valve 204 to open, and controls the second control valve 205 to close. In other words, when the overall cooling demand of all indoor units 30 in operation exceeds the heating demand, the controller controls the outdoor unit 10 to operate in condenser mode.

[0149] When ΣQc+ΣQd≤ΣQh, the controller connects the second valve port C1 of the first outdoor four-way valve 104 to the third valve port D1 of the first outdoor four-way valve 104, connects the second valve port C2 of the second outdoor four-way valve 105 to the third valve port D2 of the second outdoor four-way valve 105, controls the first control valve 204 to close, and controls the second control valve 205 to open. In other words, when the overall heating demand of all indoor units 30 in operation is greater than or equal to the cooling demand, the controller controls the outdoor unit 10 to operate in evaporator mode.

[0150] refer to Figure 8 Taking the following parameters as follows: HPh = 2kW, HPc = 1.8kW, HPh = 0.9kW; indoor unit 30 in room 1 operates in heating mode with T1 = 15℃, T2 = 20℃, T3 = 25℃; indoor unit 30 in room 2 operates in cooling mode with T1 = 35℃, T2 = 30℃, T3 = 25℃; indoor unit 30 in room 3 operates in heating / dehumidification mode with T1 = 25℃, T2 = 20℃, T3 = 28℃; and indoor unit 30 in room 4 operates in cooling / dehumidification mode with T1 = 25℃, T2 = 20℃, T3 = 23℃, ΣQh = heating demand in room 1 + heating demand of the second indoor heat exchanger 302 in room 3 + heating demand of the second indoor heat exchanger 302 in room 4 = 2 (25-15)+0.5 2 (28-20)+0.5 2 (23-20)=31;

[0151] ΣQc = Cooling demand in room 2 = 1.8 (35-25)=18;

[0152] ΣQd = Dehumidification requirement of the first indoor heat exchanger 301 in room 3 + Dehumidification requirement of the first indoor heat exchanger 301 in room 4 = 0.9 (25-20)+0.9 (25-20)=9;

[0153] Since ΣQc+ΣQd=27 and ΣQh=31, therefore ΣQc+ΣQd<ΣQh, the controller controls the outdoor unit 10 to run in evaporator mode.

[0154] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0155] For ease of explanation, the above description has been provided in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Various modifications and variations can be obtained based on the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, thereby enabling those skilled in the art to better utilize the above embodiments and various different variations of embodiments suitable for specific application considerations.

Claims

1. An air conditioning system, characterized in that, include: The outdoor unit (10) includes a refrigerant outlet pipe (107) and a refrigerant return pipe (108). The control box (20) includes a control valve assembly, a bypass pipe (203), a first control valve (204), and a second control valve (205); the control valve assembly includes a first box four-way valve (201) and a second box four-way valve (202). The third valve port (D3) of the first box four-way valve (201) and the third valve port (D4) of the second box four-way valve (202) are respectively connected to the refrigerant outlet pipe (107), and the first valve port (S3) of the first box four-way valve (201) and the first valve port (S4) of the second box four-way valve (202) are respectively connected to the refrigerant return pipe (108). The two ends of the bypass pipe (203) are respectively connected to the refrigerant outlet pipe (107) and the refrigerant return pipe (108). The first control valve (204) and the second control valve (205) are respectively disposed on the bypass pipe (203), and the first control valve (204) is closer to the refrigerant outlet pipe (107) than the second control valve (205). The indoor unit (30) includes a first indoor heat exchanger (301), a second indoor heat exchanger (302), a first indoor throttling device (303), and a second indoor throttling device (304). One end of the first indoor heat exchanger (301) is connected to the second valve port (C4) of the second box four-way valve (202), and the other end is connected to the portion of the bypass pipe (203) located between the first control valve (204) and the second control valve (205) through the first indoor throttling device (303); One end of the second indoor heat exchanger (302) is connected to the second valve port (C3) of the first box four-way valve (201), and the other end is connected to the part of the bypass pipe (203) located between the first control valve (204) and the second control valve (205) through the second indoor throttling device (304); The indoor unit (30) has a heating dehumidification mode and a cooling dehumidification mode; When the indoor unit (30) is in the heating dehumidification mode and the cooling dehumidification mode, the second valve port (C3) of the first box four-way valve (201) is connected to the third valve port (D3) of the first box four-way valve (201), and the second valve port (C4) of the second box four-way valve (202) is connected to the first valve port (S4) of the second box four-way valve (202); When the indoor unit (30) is in the heating and dehumidification mode, the first control valve (204) is closed and the second control valve (205) is open; When the indoor unit (30) is in the cooling and dehumidification mode, the first control valve (204) is open and the second control valve (205) is closed.

2. The air conditioning system according to claim 1, characterized in that, The indoor unit (30) also has a heating mode and a cooling mode; When the indoor unit (30) is in the heating mode, the second valve port (C3) of the first box four-way valve (201) is connected to the third valve port (D3) of the first box four-way valve (201), the second valve port (C4) of the second box four-way valve (202) is connected to the third valve port (D4) of the second box four-way valve (202), the first control valve (204) is closed, and the second control valve (205) is open; When the indoor unit (30) is in the cooling mode, the second valve port (C3) of the first box four-way valve (201) is connected to the first valve port (S3) of the first box four-way valve (201), the second valve port (C4) of the second box four-way valve (202) is connected to the first valve port (S4) of the second box four-way valve (202), the first control valve (204) is open, and the second control valve (205) is closed.

3. The air conditioning system according to claim 1, characterized in that, The outdoor unit (10) also includes a compressor (101), an outdoor heat exchanger (102), an outdoor throttling device (103), a first outdoor four-way valve (104), and a second outdoor four-way valve (105). The air inlet and air outlet of the compressor (101) are respectively connected to the first valve port (S1) and the third valve port (D1) of the first outdoor four-way valve (104). One end of the outdoor heat exchanger (102) is connected to the fourth valve port (E1) of the first outdoor four-way valve (104), and the other end is connected to the first valve port (S2) of the second outdoor four-way valve (105) through the outdoor throttling device (103). The third valve port (D2) of the second outdoor four-way valve (105) is connected to the second valve port (C1) of the first outdoor four-way valve (104), the second valve port (C2) of the second outdoor four-way valve (105) is connected to the refrigerant outlet pipe (107), and the fourth valve port (E2) of the second outdoor four-way valve (105) is connected to the refrigerant return pipe (108).

4. The air conditioning system according to claim 3, characterized in that, The air conditioning system further includes a controller, which is electrically connected to the first outdoor four-way valve (104), the second outdoor four-way valve (105), the first box four-way valve (201), the second box four-way valve (202), the first control valve (204), and the second control valve (205), respectively; the controller is configured to: Obtain the working mode of the indoor unit (30), and calculate the heating demand Qh, cooling demand Qc and dehumidification demand Qd of the indoor unit (30) based on the working mode; When Qc+Qd>Qh, the third valve port (D1) of the first outdoor four-way valve (104) is connected to the fourth valve port (E1) of the first outdoor four-way valve (104), the third valve port (D2) of the second outdoor four-way valve (105) is connected to the fourth valve port (E2) of the second outdoor four-way valve (105), the first control valve (204) is opened, and the second control valve (205) is closed. When Qc+Qd≤Qh, the second valve port (C1) of the first outdoor four-way valve (104) is connected to the third valve port (D1) of the first outdoor four-way valve (104), the second valve port (C2) of the second outdoor four-way valve (105) is connected to the third valve port (D2) of the second outdoor four-way valve (105), the first control valve (204) is closed, and the second control valve (205) is opened. The working modes of the indoor unit (30) include: heating mode, cooling mode, heating and dehumidification mode and cooling and dehumidification mode.

5. The air conditioning system according to claim 4, characterized in that, When the indoor unit (30) is in heating mode, Qh is the rated heating capacity of the indoor unit (30), and Qc and Qd are zero respectively; When the indoor unit (30) is in cooling mode, Qc is the rated cooling capacity of the indoor unit (30), and Qh and Qd are zero respectively; When the indoor unit (30) is in heating dehumidification mode or cooling dehumidification mode, Qd is the rated dehumidification capacity of the indoor unit (30).

6. The air conditioning system according to claim 4, characterized in that, The indoor unit (30) has an air inlet (305) and an air outlet (306). The first indoor heat exchanger (301) is closer to the air inlet (305) than the second indoor heat exchanger (302), and the second indoor heat exchanger (302) is closer to the air outlet (306) than the first indoor heat exchanger (301). The indoor unit (30) also includes a first temperature detector (307), a second temperature detector (308) and a third temperature detector (309) that are electrically connected to the controller respectively. The first temperature detector (307) is disposed between the air inlet (305) and the first indoor heat exchanger (301), the second temperature detector (308) is disposed between the first indoor heat exchanger (301) and the second indoor heat exchanger (302), and the third temperature detector (309) is disposed between the second indoor heat exchanger (302) and the air outlet (306).

7. The air conditioning system according to claim 6, characterized in that, When the indoor unit (30) is in heating mode, the indoor unit (30) only has Qh, and Qh = HPh. (T3-T1); When the indoor unit (30) is in cooling mode, the indoor unit (30) only has Qc, and Qc=HPc (T1-T3); When the indoor unit (30) is in heating / dehumidification mode or cooling / dehumidification mode, Qh = 0.5 HPh (T3-T2), Qd=0.5 HPd (T1-T2); Wherein, HPh is the rated heating capacity of the indoor unit (30), HPc is the rated cooling capacity of the indoor unit (30), HPd is the rated dehumidification capacity of the indoor unit (30), T1 is the inlet air temperature of the first indoor heat exchanger (301), T2 is the inlet air temperature of the second indoor heat exchanger (302), and T3 is the outlet air temperature of the second indoor heat exchanger (302).

8. The air conditioning system according to any one of claims 4-7, characterized in that, The air conditioning system includes a plurality of indoor units (30), which are connected in parallel. The control box (20) includes multiple control valve groups, which are arranged in parallel, and each control valve group corresponds to an indoor unit (30).

9. The air conditioning system according to claim 8, characterized in that, The controller is configured to: Obtain the operating modes of all indoor units (30) in operation, and calculate the sum of heating demand ΣQh, cooling demand ΣQc and dehumidification demand ΣQd of all indoor units (30) in operation based on the operating modes. When ΣQc+ΣQd>ΣQh, the third valve port (D1) of the first outdoor four-way valve (104) is connected to the fourth valve port (E1) of the first outdoor four-way valve (104), the third valve port (D2) of the second outdoor four-way valve (105) is connected to the fourth valve port (E2) of the second outdoor four-way valve (105), the first control valve (204) is opened, and the second control valve (205) is closed. When ΣQc+ΣQd≤ΣQh, the second valve port (C1) of the first outdoor four-way valve (104) is connected to the third valve port (D1) of the first outdoor four-way valve (104), the second valve port (C2) of the second outdoor four-way valve (105) is connected to the third valve port (D2) of the second outdoor four-way valve (105), the first control valve (204) is closed, and the second control valve (205) is opened.

10. The air conditioning system according to any one of claims 3-7, characterized in that, The outdoor unit (10) also includes a gas-liquid separator (106), the inlet of which is connected to the first valve port (S1) of the first outdoor four-way valve (104), and the outlet of which is connected to the air inlet of the compressor (101).

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