Outdoor unit of high-capacity multi-split air conditioning system

Abstract

The utility model discloses an outdoor unit of a high-capacity multi-split air conditioning system, which belongs to the technical field of air conditioners and is provided with four electromagnetic valve structures, specifically, one end of a third electromagnetic valve is connected among a four-way valve, a first one-way valve and a second one-way valve, and the other end of the third electromagnetic valve is connected to a first gas-liquid separator and a second gas-liquid separator; one end of the first electromagnetic valve is connected to the first outdoor heat exchange assembly, the other end is connected to the third electromagnetic valve, one end of the second electromagnetic valve is connected to the second outdoor heat exchange assembly, the other end is connected to the third electromagnetic valve, one end of the fourth electromagnetic valve is connected to the supercooling assembly, and the other end is connected to the first gas-liquid separator and the second gas-liquid separator. The four-way valve is not reversed during heating and defrosting, a large-displacement compressor and a large-volume gas-liquid separator can be selected, and the operation modes of the system are variable according to load changes.

Description

Technical Field

[0001] The utility model belongs to the technical field of air conditioning, and in particular relates to an outdoor unit of a large-capacity multi-connected air conditioning system. Background Art

[0002] At present, the multi-split air conditioners used in shopping malls, office buildings and other places are combined into a plurality of units, occupying a large area and having a single control. When heating, the four-way valve needs to be switched for defrosting. The reversal of the four-way valve will cause the refrigerant flow direction in the system to change to the cooling mode flow direction. The indoor unit side becomes an evaporator and no longer heats, and hot air cannot be blown out, affecting the user experience. Utility Model Content

[0003] The utility model provides a large-capacity multi-split air-conditioning system outdoor unit, which solves the problems of large floor space, single control and need for reversal of a four-way valve during defrosting in the existing multi-split air-conditioning units.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: an outdoor unit of a large-capacity multi-split air-conditioning system, comprising a four-way valve, a compressor, a gas-liquid separator, an oil separation component, a one-way valve, an outdoor heat exchange component, and a supercooling component, characterized in that: the compressor comprises a first compressor and a second compressor, the gas-liquid separator comprises a first gas-liquid separator and a second gas-liquid separator, the oil separation component comprises a first oil separation component and a second oil separation component, the one-way valve comprises a first one-way valve and a second one-way valve, the outdoor heat exchange component comprises a first outdoor heat exchange component and a second outdoor heat exchange component, and also comprises a first solenoid valve, a second solenoid valve, a third solenoid valve, and a fourth solenoid valve, the first compressor is connected to the first gas-liquid separator and the first oil separation component, the second compressor is connected to the second gas-liquid separator and the second oil separation component, the first oil separation component is connected to the first one-way valve, and the second oil separation component is connected The second one-way valve, the first one-way valve and the second one-way valve are connected to the four-way valve, the four-way valve is connected to the first outdoor heat exchange component, the second outdoor heat exchange component, and the first gas-liquid separator, the second gas-liquid separator and the gas pipe of the indoor unit, the first outdoor heat exchange component and the second outdoor heat exchange component are both connected to the supercooling component, the supercooling component is connected to the liquid pipe of the indoor unit and the first compressor and the second compressor, one end of the third solenoid valve is connected to the four-way valve and the first one-way valve and the second one-way valve, and the other end is connected to the first gas-liquid separator and the second gas-liquid separator, one end of the first solenoid valve is connected to the first outdoor heat exchange component, and the other end is connected to the third solenoid valve, one end of the second solenoid valve is connected to the second outdoor heat exchange component, and the other end is connected to the third solenoid valve, one end of the fourth solenoid valve is connected to the supercooling component and the first compressor and the second compressor, and the other end is connected to the first gas-liquid separator and the second gas-liquid separator.

[0005] Preferably, the first oil separation component includes a first oil separator and a first oil return capillary tube, and the second oil separation component includes a second oil separator and a second oil return capillary tube.

[0006] Preferably, the outdoor heat exchange component includes a first outdoor heat exchanger, a second outdoor heat exchanger, a first electronic expansion valve, and a second electronic expansion valve, the first outdoor heat exchanger is connected to the first electronic expansion valve, and the second outdoor heat exchanger is connected to the second electronic expansion valve.

[0007] Preferably, it also includes an electric ball valve, a radiator and a bypass branch, the electric ball valve is connected to the radiator and connected in parallel with the bypass branch, the first electronic expansion valve and the second electronic expansion valve are connected to the electric ball valve and the bypass branch respectively, and the radiator and the bypass branch are connected to the subcooling plate exchanger respectively.

[0008] Preferably, a third electronic expansion valve is further included, one end of the third electronic expansion valve is connected to the radiator and the bypass branch through pipelines, and the other end is connected to the subcooling plate exchanger.

[0009] Preferably, it further comprises a first oil return solenoid valve and a second oil return solenoid valve, wherein the first oil return solenoid valve and the second oil return solenoid valve are connected to the first gas-liquid separator and the second gas-liquid separator respectively.

[0010] Compared with the prior art, the beneficial effects of the utility model are:

[0011] The air-conditioning outdoor unit of the utility model is composed of two large-displacement compressors and two large-volume gas-liquid separators. The control mode of system operation is flexible and changeable, with small footprint and low cost. A solenoid valve is used between the gas-liquid separator and the heat exchanger to achieve alternate defrosting of the two outdoor heat exchangers, but the four-way valve does not reverse, thereby improving user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a structural diagram of the outdoor unit of the utility model large-capacity multi-split air-conditioning system;

[0013] Figure 2 This is a schematic diagram of the refrigerant flow direction of the outdoor unit in the high-load cooling mode of the large-capacity multi-split air-conditioning system of the utility model;

[0014] Figure 3 This is a schematic diagram of the refrigerant flow direction of the outdoor machine cooling low load mode of the utility model large-capacity multi-split air-conditioning system;

[0015] Figure 4 This is a schematic diagram of the refrigerant flow direction in the outdoor heating high-load mode of the large-capacity multi-split air-conditioning system of the utility model;

[0016] Figure 5This is a schematic diagram of the refrigerant flow direction in the outdoor heating low-load mode of the large-capacity multi-split air-conditioning system of the utility model;

[0017] Figure 6 This is a schematic diagram of the refrigerant flow direction in the defrosting mode of the first outdoor heat exchanger of the utility model;

[0018] Figure 7 This is a schematic diagram of the refrigerant flow in the defrost mode of the second outdoor heat exchanger of the utility model.

[0019] In the figure: a first compressor 1, a second compressor 2, a first oil separator 3, a second oil separator 4, a first oil return capillary 5, a second oil return capillary 6, a first non-return valve 7, a second non-return valve 8, a four-way valve 9, a first outdoor heat exchanger 10, a second outdoor heat exchanger 11, a first electronic expansion valve 12, a second electronic expansion valve 13, an electric ball valve 14, a bypass branch 15, a radiator 16, a subcooling plate exchanger 17, a third electronic expansion valve 18, a first gas-liquid separator 19, a second gas-liquid separator 20, a first oil return solenoid valve 21, a second oil return solenoid valve 22, a first solenoid valve 23, a second solenoid valve 24, a third solenoid valve 25, and a fourth solenoid valve 26. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] See also Figure 1The present embodiment provides the following technical solution: an outdoor unit of a large-capacity multi-split air-conditioning system, comprising a first compressor 1, a second compressor 2, a first oil separator 3, a second oil separator 4, a first oil return capillary 5, a second oil return capillary 6, a first check valve 7, a second check valve 8, a four-way valve 9, a first outdoor heat exchanger 10, a second outdoor heat exchanger 11, a first electronic expansion valve 12, a second electronic expansion valve 13, an electric ball valve 14, a bypass branch 15, a radiator 16, a subcooling plate exchanger 17, a third electronic expansion valve 18, a first gas-liquid separator 19, a second gas-liquid separator 20, a first oil return solenoid valve 21, a second oil return solenoid valve 22, a first solenoid valve 23, a second solenoid valve 24, a third solenoid valve 25, and a fourth solenoid valve 26. The exhaust port of the first compressor 1 is connected to the first oil separator 3 through a pipeline, and the oil return port is connected to the first oil separator 3 through a first oil return capillary 5. The exhaust port of the second compressor 2 is connected to the second oil separator 4 through a pipeline, and the oil return port is connected to the second oil separator 4 through a second oil return capillary 6. The first oil separator 3 is connected to a first one-way valve 7, and the second oil separator 4 is connected to a second one-way valve 8. The first one-way valve 7 and the second one-way valve 8 are both connected to a four-way valve 9. The four-way valve 9 is connected to a first outdoor heat exchanger 10, a second outdoor heat exchanger 11, a first gas-liquid separator 19, a second gas-liquid separator 20, and an air pipe. The first outdoor heat exchanger 10 is connected to a first electronic expansion valve 12, and the second outdoor heat exchanger 11 is connected to a second electronic expansion valve 12. expansion valve 13, the first electronic expansion valve 12 and the second electronic expansion valve 13 are both connected to the electric ball valve 14 and the bypass branch 15, the electric ball valve 14 is connected to the radiator 16, the bypass branch 15 is connected in parallel with the electric ball valve 14 and the radiator 16, the radiator 16 is connected to the subcooling plate exchanger 17, one end of the third electronic expansion valve 30 is connected between the radiator 16 and the subcooling plate exchanger 17, and the other end is connected to the subcooling plate exchanger 17, the subcooling plate exchanger 17 is connected to the liquid pipe, the first compressor 1, and the second compressor 2, one end of the third solenoid valve 25 is connected between the first check valve 7, the second check valve 8 and the four-way valve 9, and the other end is connected to the first gas-liquid separator 19 and the second gas-liquid separator 20, the first solenoid valve 23 and the second solenoid valve 24 are connected in parallel One end of the first solenoid valve 23 is connected between the first heat exchanger 10 and the first electronic expansion valve 12, and the other end is connected between the third solenoid valve 25 and the four-way valve 9. One end of the second solenoid valve 24 is connected between the second heat exchanger 11 and the second electronic expansion valve 13, and the other end is connected between the third solenoid valve 25 and the four-way valve 9. One end of the fourth solenoid valve 26 is connected to the first gas-liquid separator 19 and the second gas-liquid separator 20, and the other end is connected to the first compressor 1 and the second compressor 2. The first gas-liquid separator 19 and the second gas-liquid separator 20 are respectively connected to the first oil return solenoid valve 21 and the second oil return solenoid valve 22. The first oil return solenoid valve 21 and the second oil return solenoid valve 22 are respectively connected to the first oil return capillary 5 and the first compressor 1.Between the second oil return capillary 6 and the second compressor 2.

[0022] In the air conditioning operation mode 1 of this embodiment, the refrigerant flows as follows: Figure 2 As shown, in normal cooling mode, when the load is high, Figure 2 The process shown in the figure is carried out. At this time, the first solenoid valve 23 and the second solenoid valve 24 are in the closed state, and the fourth solenoid valve 26 is in the open state. The main flow direction of the refrigerant in the system is: the high-temperature and high-pressure gas compressed by the first compressor 1 and the second compressor 2 passes through the first oil separator 3 and the second oil separator 4 and then reaches the four-way valve 9, flows from the D port of the four-way valve 9 to the C port, enters the first outdoor heat exchanger 10 and the second outdoor heat exchanger 11, and becomes a high-temperature liquid after being condensed by the heat exchanger. A part of it flows to the radiator 16 through the electric ball valve 14, which is used for cooling the electric control board, and a part of it continues to flow in the bypass branch 15. After mixing, it flows through the cold plate exchanger 17, and the subcooling degree of the liquid refrigerant increases, and then it flows to the indoor unit; after evaporation through the indoor unit heat exchanger, it flows The returned low-temperature and low-pressure gas flows to the four-way valve 9 through the gas pipe, flows from the E port of the four-way valve 9 to the S port, and flows to the first gas-liquid separator 19 and the second gas-liquid separator 20. In addition, a part of the liquid refrigerant before the subcooling plate exchanger 17 is throttled by the third electronic expansion valve 18 to become a gas-liquid mixture. The liquid refrigerant in the mainstream path is subcooled by the subcooling plate exchanger 17, and the low-temperature and low-pressure gas-liquid mixture absorbs heat and becomes a low-pressure gas, which flows to the first gas-liquid separator 19 and the second gas-liquid separator 20 through the fourth solenoid valve 26, and then flows to the return air port of the first compressor 1 and the second compressor 2, and continues to be compressed to complete the cycle.

[0023] In the air conditioning operation mode 2 of this embodiment, the refrigerant flows as follows: Figure 3 As shown, in cooling mode, when the load is low, only one compressor can be turned on, and only part of the outdoor heat exchanger can be used. Figure 3The process shown is carried out. For example, the first compressor 1 is turned on and the first outdoor heat exchanger 10 is used. At this time, the second electronic expansion valve 13 is in the closed state, the first solenoid valve 23 and the second solenoid valve 24 are in the closed state, and the fourth solenoid valve 26 is in the open state. The main flow direction of the refrigerant in the system is: the high-temperature and high-pressure gas compressed by the first compressor 1 passes through the first oil separator 3, reaches the four-way valve 9, flows from the D port of the four-way valve 9 to the C port, enters the first outdoor heat exchanger 10, and becomes a high-temperature liquid after being condensed by the first outdoor heat exchanger 10. A part of it flows to the radiator 16 through the electric ball valve 14, which is used for cooling the electric control board, and a part of it continues to flow in the bypass branch 15. After mixing, it flows through the cold plate exchanger 17, and the subcooling degree of the liquid refrigerant increases, and then it flows to the indoor unit; the low-temperature and low-pressure refrigerant that flows back after evaporation through the indoor unit heat exchanger The gas flows to the four-way valve 9 through the gas pipe, flows from the E port of the four-way valve 9 to the S port, and flows to the first gas-liquid separator 19 and the second gas-liquid separator 20. In addition, a part of the liquid refrigerant before the subcooling plate exchanger 17 is throttled by the third electronic expansion valve 18 to become a gas-liquid mixture. The liquid refrigerant in the mainstream path is supercooled by the subcooling plate exchanger 17, and the low-temperature and low-pressure gas-liquid mixture absorbs heat and becomes a low-pressure gas. It flows to the first gas-liquid separator 19 and the second gas-liquid separator 20 through the fourth solenoid valve 26, and then flows to the return air port of the first compressor 1, and continues to be compressed to complete the cycle.

[0024] In the air conditioning operation mode 3 of this embodiment, the refrigerant flows as follows: Figure 4 As shown, in heating mode, when the load is high, Figure 4 The process shown in the figure is carried out. At this time, the first solenoid valve 23 and the second solenoid valve 24 are in the closed state, and the fourth solenoid valve 26 is in the closed state. The main flow direction of the refrigerant in the system is: the high-temperature and high-pressure gas compressed by the first compressor 1 and the second compressor 2 passes through the first oil separator 3 and the second oil separator 4, reaches the four-way valve 9, flows from the D port of the four-way valve 9 to the E port, flows to the indoor unit through the gas pipe, and the high-temperature liquid condensed in the indoor unit flows to the outdoor unit through the liquid pipe after being throttled by the electronic expansion valve of the indoor unit, flows through the cold plate exchanger 17, and becomes a low-temperature and low-pressure gas-liquid mixture after being throttled by the first electronic expansion valve 12 and the second electronic expansion valve 13, and flows to the first outdoor heat exchanger 10 and the second outdoor heat exchanger 11. Exchanger 11 absorbs heat and evaporates to become low-pressure gas, then flows to the four-way valve 9, flows from the C port of the four-way valve 9 to the S port, and then flows to the first gas-liquid separator 19 and the second gas-liquid separator 20, returns to the return air port of the first compressor 1 and the second compressor 2, and then is compressed; in addition, a part of the liquid refrigerant that flows through the cold plate exchanger 17 is throttled by the third electronic expansion valve 18 to become a gas-liquid mixture, absorbs the heat of the refrigerant in the main circuit of the supercooling plate exchanger 17, and the medium-pressure gas returns to the medium-pressure chamber of the first compressor 1 and the second compressor 2 for compression to complete the cycle.

[0025] In the air conditioning operation mode 4 of this embodiment, the refrigerant flows as follows: Figure 5As shown, in heating mode, when the load is low, only one compressor can be turned on, and only part of the outdoor heat exchanger can be used. Figure 5 For example, the first compressor 1 is turned on and the first outdoor heat exchanger 10 is used, at which time the first solenoid valve 23 and the second solenoid valve 24 are closed, the second electronic expansion valve 13 is closed, and the fourth solenoid valve 26 is closed. The main flow direction of the refrigerant in the system is as follows: the high-temperature and high-pressure gas compressed by the first compressor 1 passes through the first oil separator 3, reaches the four-way valve 9, flows from the D port of the four-way valve 9 to the E port, flows to the indoor unit through the gas pipe, and the high-temperature liquid condensed in the indoor unit flows to the outdoor unit through the liquid pipe after being throttled by the electronic expansion valve of the indoor unit, flows through the cold plate exchanger 17, becomes a low-temperature and low-pressure gas-liquid mixture after being throttled by the first electronic expansion valve 12, flows to the first outdoor heat exchanger 10, absorbs heat and evaporates to become a low-pressure gas, then flows to the four-way valve 9, flows from the C port of the four-way valve 9 to the S port, then flows to the first gas-liquid separator 19 and the second gas-liquid separator 20, returns to the return air port of the first compressor 1, and then is compressed; in addition, a part of the liquid refrigerant after flowing through the cold plate exchanger 17 is throttled by the third electronic expansion valve 18 to become a gas-liquid mixture, absorbs the heat of the refrigerant in the main circuit of the supercooling plate exchanger 17, and the medium-pressure gas returns to the medium-pressure chamber of the first compressor 1 to be compressed to complete the cycle.

[0026] In the air conditioning operation mode 5 of this embodiment, the refrigerant flows as follows: Figure 6 , 7 As shown, when heating in a low temperature environment, the outdoor heat exchanger will frost. In this embodiment, the two outdoor heat exchangers can be defrosted alternately, and the four-way valve 9 does not switch when defrosting. The defrosting process of the first outdoor heat exchanger 10 is as follows Figure 6As shown: when the first outdoor heat exchanger 10 is defrosted, the first solenoid valve 23 is in the open state, the second solenoid valve 24 is in the closed state, and the first electronic expansion valve 12 is in the closed state. The main flow direction of the refrigerant in the system is: after the high-temperature and high-pressure gas compressed by the first compressor 1 and the second compressor 2 passes through the first oil separator 3 and the second oil separator 4, a part of the high-temperature and high-pressure gas flows to the first outdoor heat exchanger 10 through the first solenoid valve 23, and becomes liquid after being condensed by the first outdoor heat exchanger 10. The first outdoor heat exchanger 10 completes defrosting, and a part of it goes to the four-way valve 9, flows from the D port of the four-way valve 9 to the E port, and flows to the indoor unit through the gas pipe. The high-temperature liquid refrigerant after condensation in the indoor unit is throttled by the electronic expansion valve of the indoor unit and flows to the outdoor unit through the liquid pipe, flows through the cold plate exchanger 17, and becomes a low-temperature and low-pressure gas-liquid mixture after being throttled by the second electronic expansion valve 13, and flows to the second outdoor heat exchanger 11. , absorbs heat and evaporates to become a low-pressure gas. The liquid refrigerant flowing out of the first outdoor heat exchanger 10 and the gas refrigerant flowing out of the second outdoor heat exchanger 11 are mixed and flow to the four-way valve 9, and flow from the C port of the four-way valve 9 to the S port, and then flow to the first gas-liquid separator 19 and the second gas-liquid separator 20. The liquid refrigerant is stored in the gas after separation, and the gaseous refrigerant returns to the return air port of the first compressor 1 and the second compressor 2, and then is compressed; in addition, a part of the liquid refrigerant that flows through the cold plate exchanger 17 is throttled by the third electronic expansion valve 18 to become a gas-liquid mixture, absorbs the heat of the refrigerant in the main circuit of the supercooling plate exchanger 17, and the medium-pressure gas returns to the medium-pressure chamber of the first compressor 1 and the second compressor 2 for compression to complete the cycle.

[0027] The defrosting process of the second outdoor heat exchanger 11 is as follows Figure 7As shown: when the second outdoor heat exchanger 11 is defrosted, the second solenoid valve 24 is in the open state, the first solenoid valve 23 is in the closed state, and the second electronic expansion valve 13 is in the closed state. The main flow direction of the refrigerant in the system is: after the high-temperature and high-pressure gas compressed by the first compressor 1 and the second compressor 2 passes through the first oil separator 3 and the second oil separator 4, a part of the high-temperature and high-pressure gas flows to the second outdoor heat exchanger 11 through the second solenoid valve 24, and becomes liquid after condensation by the second outdoor heat exchanger 11. The second outdoor heat exchanger 11 completes defrosting, and a part of it goes to the four-way valve 9, flows from the D port of the four-way valve 9 to the E port, and flows to the indoor unit through the gas pipe. The high-temperature liquid after condensation in the indoor unit is throttled by the electronic expansion valve of the indoor unit and flows to the outdoor unit through the liquid pipe, flows through the cold plate exchanger 17, and becomes a low-temperature and low-pressure gas-liquid mixture after throttling by the first electronic expansion valve 12, and flows to the first outdoor heat exchanger 10. After absorbing heat and evaporating, it becomes a low-pressure gas. The liquid refrigerant flowing out of the second outdoor heat exchanger 11 and the gaseous refrigerant flowing out of the first outdoor heat exchanger 10 are mixed and flow to the four-way valve 9, and flow from the C port of the four-way valve 9 to the S port, and then flow to the first gas-liquid separator 19 and the second gas-liquid separator 20. The liquid refrigerant is stored in the gas after separation, and the gaseous refrigerant returns to the return air port of the first compressor 1 and the second compressor 2, and then is compressed; in addition, a part of the liquid refrigerant that flows through the cold plate exchanger 17 is throttled by the third electronic expansion valve 18 to become a gas-liquid mixture, absorbs the heat of the refrigerant in the main circuit of the supercooling plate exchanger 17, and the medium-pressure gas returns to the medium-pressure chamber of the first compressor 1 and the second compressor 2 for compression to complete the cycle.

[0028] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An outdoor unit of a large-capacity multi-split air conditioning system, comprising a four-way valve, a compressor, a gas-liquid separator, an oil separation component, a one-way valve, an outdoor heat exchange component, and a supercooling component, characterized in that: The compressor comprises a first compressor and a second compressor, the gas-liquid separator comprises a first gas-liquid separator and a second gas-liquid separator, the oil separation component comprises a first oil separation component and a second oil separation component, the one-way valve comprises a first one-way valve and a second one-way valve, the outdoor heat exchange component comprises a first outdoor heat exchange component and a second outdoor heat exchange component, and further comprises a first solenoid valve, a second solenoid valve, a third solenoid valve and a fourth solenoid valve, the first compressor is connected to the first gas-liquid separator and the first oil separation component, the second compressor is connected to the second gas-liquid separator and the second oil separation component, the first oil separation component is connected to the first one-way valve, the second oil separation component is connected to the second one-way valve, the first one-way valve and the second one-way valve are connected to a four-way valve, and the four-way valve is connected to the first outdoor heat exchange component, The second outdoor heat exchange component, and the first gas-liquid separator, the second gas-liquid separator and the gas pipe of the indoor unit, the first outdoor heat exchange component and the second outdoor heat exchange component are both connected to the subcooling component, the subcooling component is connected to the liquid pipe of the indoor unit and the first compressor and the second compressor, one end of the third solenoid valve is connected to the four-way valve and the first check valve, the second check valve, and the other end is connected to the first gas-liquid separator and the second gas-liquid separator, one end of the first solenoid valve is connected to the first outdoor heat exchange component, and the other end is connected to the third solenoid valve, one end of the second solenoid valve is connected to the second outdoor heat exchange component, and the other end is connected to the third solenoid valve, one end of the fourth solenoid valve is connected to the subcooling component and the first compressor, the second compressor, and the other end is connected to the first gas-liquid separator and the second gas-liquid separator.

2. The outdoor unit of the large-capacity multi-split air conditioning system according to claim 1, characterized in that: The first oil separation assembly includes a first oil separator and a first oil return capillary tube, and the second oil separation assembly includes a second oil separator and a second oil return capillary tube.

3. The outdoor unit of the large-capacity multi-split air conditioning system according to claim 1, characterized in that: The outdoor heat exchanger assembly includes a first outdoor heat exchanger, a second outdoor heat exchanger, a first electronic expansion valve, and a second electronic expansion valve. The first outdoor heat exchanger is connected to the first electronic expansion valve, and the second outdoor heat exchanger is connected to the second electronic expansion valve.

4. The outdoor unit of the large-capacity multi-split air conditioning system according to claim 3 is characterized in that: It also includes an electric ball valve, a radiator, and a bypass branch. The electric ball valve is connected to the radiator and is connected in parallel to the bypass branch. The first electronic expansion valve and the second electronic expansion valve are connected to the electric ball valve and the bypass branch respectively. The radiator and the bypass branch are connected to the subcooling plate exchanger respectively.

5. The outdoor unit of the large-capacity multi-split air conditioning system according to claim 4, characterized in that: It also includes a third electronic expansion valve, one end of which is connected to the radiator and the bypass branch through pipelines, and the other end is connected to the supercooling plate exchanger.

6. The outdoor unit of the large-capacity multi-split air conditioning system according to claim 1, characterized in that: It also includes a first oil return solenoid valve and a second oil return solenoid valve, wherein the first oil return solenoid valve and the second oil return solenoid valve are connected to the first gas-liquid separator and the second gas-liquid separator respectively.

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