Control method of air conditioning system and air conditioning system

Abstract

The invention relates to the technical field of air conditioners, particularly provides a control method of an air conditioning system and the air conditioning system, and aims to solve the problem that a crankshaft is abraded due to the fact that oil return of a compressor is not timely when an existing air conditioning system is in a high-temperature refrigeration working condition. In order to achieve the purpose, the air conditioning system comprises a compressor and a gas-liquid separation device which are communicated with each other in a refrigerant circulation main loop; when the air conditioning system is in a refrigeration mode, the control method comprises the steps that the outdoor environment temperature is obtained; and according to the outdoor environment temperature, the gas-liquid separation device is controlled to selectively adopt a centrifugal separation mode and / or a gravity separation mode to carry out gas-liquid separation on the refrigerant. The gas-liquid separation device can be switched to adopt different gas-liquid separation modes for refrigerants according to different outdoor environment temperatures, the requirement of a compressor for compressor oil under the high-temperature refrigeration working condition of an air conditioner system can be met, the oil return rate of the compressor is increased, it is guaranteed that oil return of the compressor is timely, and crankshaft abrasion is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and specifically provides a control method of an air conditioning system and an air conditioning system. Background Art

[0002] When the air conditioning system is in normal refrigeration conditions, the compressor oil return is usually achieved by increasing the operating frequency of the compressor to increase the circulation rate of the refrigerant. Since the compressor oil and the refrigerant are miscible liquids, increasing the circulation rate of the refrigerant also increases the compressor oil return rate. However, when the air conditioning system is in high-temperature refrigeration conditions, due to the high outdoor load, the operating frequency of the compressor is usually reduced due to excessive exhaust pressure, which will reduce the compressor oil return rate. In addition, due to the high condensing temperature, the compressor oil return is easily delayed during operation, causing crankshaft wear.

[0003] Therefore, this field needs a new technical solution to solve the above problems. Summary of the invention

[0004] The present invention aims to solve the above technical problem, that is, to solve the problem of crankshaft wear caused by untimely oil return of the compressor in the existing air-conditioning system under high-temperature refrigeration conditions.

[0005] In a first aspect, the present invention provides a control method for an air-conditioning system, wherein the air-conditioning system includes a compressor and a gas-liquid separation device connected to each other in a main refrigerant circulation loop; when the air-conditioning system is in a cooling mode, the control method includes: obtaining the outdoor ambient temperature; according to the outdoor ambient temperature, controlling the gas-liquid separation device to selectively adopt a centrifugal separation mode and / or a gravity separation mode to perform gas-liquid separation on the refrigerant.

[0006] In a specific implementation of the control method of the above-mentioned air-conditioning system, the step of "controlling the gas-liquid separation device to selectively adopt a centrifugal separation mode and / or a gravity separation mode to perform gas-liquid separation on the refrigerant according to the outdoor ambient temperature" specifically includes: when the outdoor ambient temperature is less than or equal to a first preset outdoor ambient temperature, controlling the gas-liquid separation device to adopt a gravity separation mode to perform gas-liquid separation on the refrigerant.

[0007] In a specific implementation of the control method of the above-mentioned air-conditioning system, the step of "controlling the gas-liquid separation device to selectively adopt a centrifugal separation mode and / or a gravity separation mode to perform gas-liquid separation on the refrigerant according to the outdoor ambient temperature" further includes: when the outdoor ambient temperature is greater than the first preset outdoor ambient temperature but less than or equal to the second preset outdoor ambient temperature, controlling the gas-liquid separation device to adopt a gravity separation mode to perform gas-liquid separation on a portion of the refrigerant, and adopting a centrifugal separation mode to perform gas-liquid separation on another portion of the refrigerant.

[0008] In a specific implementation of the control method of the above-mentioned air-conditioning system, the step of "controlling the gas-liquid separation device to perform gas-liquid separation in a gravity separation mode on a portion of the refrigerant, and to perform gas-liquid separation in a centrifugal separation mode on another portion of the refrigerant" specifically includes: first controlling the gas-liquid separation device to perform gas-liquid separation in a gravity separation mode on a portion of the refrigerant, and then controlling the gas-liquid separation device to perform gas-liquid separation in a centrifugal separation mode on another portion of the refrigerant; or controlling the gas-liquid separation device to perform gas-liquid separation alternately in a gravity separation mode on a portion of the refrigerant and in a centrifugal separation mode on another portion of the refrigerant.

[0009] In a specific implementation of the control method of the above-mentioned air-conditioning system, the step of "controlling the gas-liquid separation device to selectively adopt a centrifugal separation mode and / or a gravity separation mode to perform gas-liquid separation on the refrigerant according to the outdoor ambient temperature" further includes: when the outdoor ambient temperature is greater than a second preset outdoor ambient temperature, controlling the gas-liquid separation device to adopt a centrifugal separation mode to perform gas-liquid separation on the refrigerant.

[0010] In a specific implementation of the control method of the above-mentioned air-conditioning system, the gas-liquid separation device includes a first shell, a second shell, a centrifugal separation component and a valve, the first shell has a first chamber, a gravity separation zone is formed in the first chamber, the second shell is arranged in the first chamber, the second shell has a second chamber, a centrifugal separation zone is formed in the second chamber, the centrifugal separation component is arranged in the centrifugal separation zone, and the heat exchange device of the air-conditioning system can be selectively connected to the gravity separation zone or the centrifugal separation zone with the help of the valve; the control method of the gas-liquid separation device using the gravity separation mode to separate the refrigerant into gas and liquid specifically includes: controlling the heat exchange device to be connected to the gravity separation zone with the help of the valve; controlling the centrifugal separation component to be de-energized.

[0011] In a specific implementation of the control method of the above-mentioned air-conditioning system, a first refrigerant inlet, a first refrigerant outlet and a first oil return port connected to the gravity separation zone are provided on the first shell; "controlling the heat exchange device to be connected to the gravity separation zone by means of the valve" specifically means: controlling the heat exchange device to be connected to the first refrigerant inlet by means of the valve, controlling the first refrigerant outlet to be connected to the air intake port of the compressor, and controlling the first oil return port to be connected to the oil intake port of the compressor.

[0012] In a specific implementation of the control method of the above-mentioned air-conditioning system, the control method of the gas-liquid separation device using a centrifugal separation mode to separate the refrigerant into gas and liquid specifically includes: controlling the heat exchange device of the air-conditioning system to be connected to the centrifugal separation area via the valve; controlling the centrifugal separation component to be energized and work.

[0013] In a specific implementation of the control method of the above-mentioned air-conditioning system, a second refrigerant inlet, a second refrigerant outlet and a second oil return port connected to the centrifugal separation area are provided on the second shell; "controlling the compressor to be connected to the centrifugal separation area" specifically means: controlling the heat exchange device to be connected to the second refrigerant inlet by means of the valve, controlling the second refrigerant outlet to be connected to the gravity separation area, and controlling the second oil return port to be connected to the oil suction port of the compressor.

[0014] In a second aspect, the present invention further provides an air conditioning system, comprising a controller, wherein the controller is configured to execute the control method described above.

[0015] When the above-mentioned technical scheme is adopted, the control method of the air-conditioning system provided by the present invention can switch the gas-liquid separation device according to different outdoor ambient temperatures to adopt different separation modes to separate the refrigerant into gas and liquid, namely, gravity separation mode and / or centrifugal separation mode. Since the mixture of refrigerant and compressor oil is separated by centrifugation compared with gravity separation, the return oil volume of the separated compressor oil is larger and the amount of separated refrigerant is less. Therefore, the demand of the compressor for compressor oil of the air-conditioning system under high-temperature refrigeration conditions can be met, the oil return rate of the compressor can be increased, the oil return mechanism of the compressor can be ensured, and crankshaft wear can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings, in which:

[0017] Figure 1 is a schematic diagram of the refrigerant circulation of the air-conditioning system of the present invention;

[0018] Figure 2 It is a structural schematic diagram of a gas-liquid separation device in an air conditioning system of the present invention;

[0019] Figure 3 is a flow chart of the main steps of the control method of the air conditioning system of the present invention;

[0020] Figure 4 is a possible complete flow chart of the control method of the air conditioning system of the present invention;

[0021] List of reference numerals:

[0022] 1. Compressor; 2. Indoor heat exchanger; 3. Four-way reversing valve; 4. Outdoor heat exchanger; 5. Throttling device; 6. Gas-liquid separation device; 61. First shell; 611. Gravity separation zone; 612. First refrigerant inlet; 613. First refrigerant outlet; 614. First oil return port; 62. Second shell; 621. Centrifugal separation zone; 622. Second refrigerant inlet; 623. Second refrigerant outlet; 624. Second oil return port; 63. Valve. DETAILED DESCRIPTION

[0023] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not used to limit the scope of protection of the present invention. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0024] It should be noted that in the description of the present invention, the terms such as "inside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the relevant devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, ordinal numbers such as "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0025] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In addition, it should be noted that in the description of the present invention, although the various steps of the control method of the present invention are described in this application in a specific order, these orders are not restrictive. Without departing from the basic principles of the present invention, those skilled in the art can perform the steps in a different order.

[0027] See first Figure 1 and Figure 2 ,in, Figure 1 is a schematic diagram of the refrigerant circulation principle of the air-conditioning system of the present invention, Figure 2 Schematic diagram of the structure of the gas-liquid separation device 6 in the air conditioning system of the present invention. Figure 1 As shown, the air-conditioning system includes a compressor 1, a heat exchange device, a gas-liquid separation device 6 and a four-way reversing valve 3. The heat exchange device includes an indoor heat exchanger 2, a throttling device 5 and an outdoor heat exchanger 4. By switching the connection mode of the four-way reversing valve 3, the refrigerant passes through the exhaust port of the compressor 1, the outdoor heat exchanger 4, the throttling device 5, the indoor heat exchanger 2 and the gas-liquid separation device 6 in sequence to form a refrigeration cycle loop.

[0028] It should be noted that the present invention does not impose any limitation on the specific structure of the main refrigerant circulation loop, and those skilled in the art can set it according to actual use requirements, as long as the main refrigerant circulation loop is provided with a compressor 1, an outdoor heat exchanger 4, a throttling device 5, an indoor heat exchanger 2 and a gas-liquid separation device 6; and the present invention does not impose any limitation on the specific types of each component, for example, the throttling device 5 can be set to an electronic expansion valve, a thermal expansion valve or a capillary tube, which is not restrictive.

[0029] like Figure 2 As shown, the gas-liquid separation device 6 includes a first shell 61, a second shell 62, a centrifugal separation assembly (not shown in the figure) and a valve 63. The first shell 61 has a first chamber, and a gravity separation zone 611 is formed in the first chamber. The second shell 62 is arranged in the first chamber, and the second shell 62 has a second chamber, and a centrifugal separation zone 621 is formed in the second chamber. The centrifugal separation assembly is arranged in the centrifugal separation zone 621, and the heat exchange device can be selectively connected to the gravity separation zone 611 or the centrifugal separation zone 621 by means of the valve 63.

[0030] Specifically, the first shell 61 is provided with a first refrigerant inlet 612, a first refrigerant outlet 613 and a first oil return port 614 which are connected to the gravity separation zone 611. The indoor heat exchanger 2 can be connected to the first refrigerant inlet 612 by means of a valve 63. The first refrigerant outlet 613 is connected to the air intake port of the compressor 1. The first oil return port 614 is connected to the oil intake port of the compressor 1. When the gas-liquid separation device 6 adopts the gravity separation mode, since the liquid and gaseous refrigerant flowing out of the indoor heat exchanger 2 is mixed with the compressor oil, the refrigerant enters the gravity separation zone 611 through the first refrigerant inlet 612. After gravity separation, the compressor oil flows back to the oil intake port of the compressor 1 through the first oil return port 614, and the gaseous refrigerant flows to the air intake port of the compressor 1 through the first refrigerant outlet 613. The second shell 62 is provided with a second refrigerant inlet 622, a second refrigerant outlet 623 and a second oil return port 624 which are connected to the centrifugal separation area 621. The indoor heat exchanger 2 can be connected to the second refrigerant inlet 622 by means of a valve 63. The second refrigerant outlet 623 is connected to the gravity separation area 611. The second oil return port 624 is connected to the oil suction port of the compressor 1. When the gas-liquid separation device 6 adopts the centrifugal separation mode, since the liquid and gaseous refrigerant flowing out of the indoor heat exchanger 2 is mixed with the compressor oil, the refrigerant enters the centrifugal separation area 621 through the second refrigerant inlet 622. After centrifugal separation, the compressor oil flows back to the oil suction port of the compressor 1 through the second oil return port 624, and the gaseous refrigerant first flows to the gravity separation area 611 through the second refrigerant outlet 623, and then flows to the suction port of the compressor 1 through the first refrigerant outlet 613.

[0031] Exemplarily, the valve 63 is a three-way solenoid valve with one inlet and two outlets. The inlet of the valve 63 is connected to the four-way reversing valve 3, and the two outlets of the valve 63 are connected to the first refrigerant inlet 612 and the second refrigerant inlet 622 respectively.

[0032] The centrifugal separation assembly includes a driving mechanism (not shown in the figure) and a rotating mechanism (not shown in the figure), and the driving end of the driving mechanism is connected to the rotating mechanism to drive the rotating mechanism to rotate to achieve the purpose of gas-liquid separation. The driving mechanism is set as a motor, and the rotating mechanism is set as an impeller.

[0033] See below Figure 3 , which is a flow chart of the main steps of the control method of the air conditioning system of the present invention. Figure 3 As shown, when the air conditioning system is in cooling mode, the control method of the present invention includes the following steps:

[0034] S1, obtain the outdoor ambient temperature;

[0035] S2, according to the outdoor ambient temperature, controlling the gas-liquid separation device 6 to selectively adopt a centrifugal separation mode and / or a gravity separation mode to perform gas-liquid separation on the refrigerant.

[0036] Specifically, in step S2, the step of "controlling the gas-liquid separation device 6 to selectively adopt the centrifugal separation mode and / or the gravity separation mode to perform gas-liquid separation on the refrigerant according to the outdoor ambient temperature" specifically includes:

[0037] S21, when the outdoor ambient temperature is less than or equal to the first preset outdoor ambient temperature, the gas-liquid separation device 6 is controlled to perform gas-liquid separation on the refrigerant in a gravity separation mode.

[0038] S22, when the outdoor ambient temperature is greater than the first preset outdoor ambient temperature but less than or equal to the second preset outdoor ambient temperature, the gas-liquid separation device 6 is controlled to perform gas-liquid separation on a portion of the refrigerant using a gravity separation mode and to perform gas-liquid separation on another portion of the refrigerant using a centrifugal separation mode.

[0039] S23, when the outdoor ambient temperature is greater than the second preset outdoor ambient temperature, the gas-liquid separation device 6 is controlled to perform gas-liquid separation on the refrigerant in a centrifugal separation mode.

[0040] Furthermore, the control method of the gas-liquid separation device 6 using the gravity separation mode to separate the refrigerant gas and liquid specifically includes:

[0041] The heat exchange device is controlled to communicate with the gravity separation zone 611 via valve 63;

[0042] The control centrifugal separation component is not powered.

[0043] Among them, "controlling the heat exchange device to be connected with the gravity separation zone 611 by means of the valve 63" specifically means: controlling the heat exchange device to be connected with the first refrigerant inlet 612 by means of the valve, controlling the first refrigerant outlet 613 to be connected with the air intake port of the compressor, and controlling the first oil return port 614 to be connected with the oil intake port of the compressor.

[0044] Furthermore, the control method of the gas-liquid separation device 6 using the centrifugal separation mode to separate the refrigerant into gas and liquid specifically includes:

[0045] The heat exchange device is controlled to communicate with the centrifugal separation area 621 via valve 63;

[0046] Control the centrifugal separation component to be powered on and work.

[0047] Among them, “controlling the compressor 1 to communicate with the centrifugal separation area 621” specifically means:

[0048] The heat exchange device is controlled to communicate with the second refrigerant inlet 622 via the valve 63 , the second refrigerant outlet 623 is controlled to communicate with the gravity separation area 611 , and the second oil return port 624 is controlled to communicate with the oil suction port of the compressor 1 .

[0049] In the above steps, illustratively, the first preset outdoor ambient temperature is 35° C., and the second preset outdoor ambient temperature is 40° C. It should be noted that the present invention does not impose any restrictions on the specific values ​​of the first preset outdoor ambient temperature and the second preset outdoor ambient temperature, and those skilled in the art can set them according to actual use requirements.

[0050] Specifically, in step S21, when the outdoor ambient temperature is less than or equal to 35°C, the system refrigerant circulates normally, the centrifugal separation component is not energized, and the mixture of refrigerant and compressor oil flowing out of the indoor heat exchanger 2 does not flow through the centrifugal separation component. It is connected to the first refrigerant inlet 612 through valve 63, so that the mixture of refrigerant and compressor oil enters the gravity separation area 611, and the separated compressor oil returns to the compressor 1 through the first oil return port 614.

[0051] In step S22, when the outdoor ambient temperature is greater than 35°C but less than or equal to 40°C, the system refrigerant circulates normally, the centrifugal separation component is powered on and works, and a portion of the mixture of refrigerant and compressor oil flowing out of the indoor heat exchanger 2 enters the gravity separation area 611 through the valve 63. At this time, the indoor heat exchanger 2 is connected to the first refrigerant inlet 612 through the valve 63, and the other portion enters the centrifugal separation area 621. At this time, the indoor heat exchanger 2 is connected to the second refrigerant inlet 622 through the valve 63, so that a portion of the separated compressor oil returns to the compressor 1 through the first oil return port 614, and the other portion returns to the compressor 1 through the second oil return port 624. In actual operation, when the refrigerant uses the gravity separation mode for gas-liquid separation, the centrifugal separation component is in a standby state. In addition, the ratio of the refrigerant using the gravity separation mode or the centrifugal separation mode is adjusted according to the model of the centrifugal separation component.

[0052] In step S23, when the outdoor ambient temperature is greater than 40°C, due to the high outdoor ambient temperature, the exhaust pressure of compressor 1 is relatively large. At this time, the system will reduce the operating frequency of compressor 1. As a result, the demand for refrigerant is relatively weak, and the demand for compressor oil is relatively large. Therefore, in order to ensure the demand for compressor oil, the centrifugal separation component is energized and works, and the mixture of refrigerant and compressor oil flowing out of the indoor heat exchanger 2 enters the centrifugal separation area 621 with the help of valve 63. That is, the indoor heat exchanger 2 is connected to the second refrigerant inlet 622 with the help of valve 63, so that the separated compressor oil returns to the compressor 1 through the second oil return port 624.

[0053] Further, in step S22, the step of "controlling the gas-liquid separation device 6 to perform gas-liquid separation on a portion of the refrigerant in a gravity separation mode and to perform gas-liquid separation on another portion of the refrigerant in a centrifugal separation mode" specifically includes:

[0054] S221, first control the gas-liquid separation device 6 to perform gas-liquid separation on a portion of the refrigerant using a gravity separation mode, and then control the gas-liquid separation device 6 to perform gas-liquid separation on another portion of the refrigerant using a centrifugal separation mode.

[0055] It should be noted that, in addition to the above-mentioned step of "first adopting the gravity separation mode, then adopting the centrifugal separation mode", it is also possible to "first control the gas-liquid separation device 6 to adopt the centrifugal separation mode for a part of the refrigerant, and then control the gas-liquid separation device 6 to adopt the gravity separation mode for another part of the refrigerant". The above adjustment is also within the protection scope of the present invention.

[0056] In addition, in an alternative embodiment, in step S22, the step of "controlling the gas-liquid separation device 6 to perform gas-liquid separation on a portion of the refrigerant in a gravity separation mode and to perform gas-liquid separation on another portion of the refrigerant in a centrifugal separation mode" specifically includes:

[0057] S2211, controlling the gas-liquid separation device 6 to perform gas-liquid separation alternately by using a gravity separation mode for a portion of the refrigerant and by using a centrifugal separation mode for another portion of the refrigerant.

[0058] See below Figure 4 , a possible control process of the present invention is introduced. Figure 4 As shown, a possible complete process of the control method of the present invention is:

[0059] S101, obtaining the outdoor ambient temperature T;

[0060] S102, comparing the outdoor ambient temperature T with the first preset outdoor ambient temperature T1 and the second preset outdoor ambient temperature T2;

[0061] When T≤T1, execute step S103;

[0062] When T1<T≤T2, execute step S104;

[0063] When T>T2, execute step S105;

[0064] S103, controlling the gas-liquid separation device 6 to perform gas-liquid separation on the refrigerant in a gravity separation mode;

[0065] S104, controlling the gas-liquid separation device 6 to perform gas-liquid separation on a portion of the refrigerant using a gravity separation mode, and to perform gas-liquid separation on another portion of the refrigerant using a centrifugal separation mode;

[0066] S105, controlling the gas-liquid separation device 6 to adopt a centrifugal separation mode to perform gas-liquid separation on the refrigerant.

[0067] The control method of the air-conditioning system provided by the present invention can switch the gas-liquid separation device 6 according to different outdoor ambient temperatures to adopt different separation modes to separate the refrigerant into gas and liquid, namely, gravity separation mode and / or centrifugal separation mode. Since the mixture of the refrigerant and the compressor oil is separated by centrifugation compared with gravity separation, the return oil volume of the separated compressor oil is larger and the amount of separated refrigerant is less. Therefore, the demand of the compressor for compressor oil of the air-conditioning system under high-temperature refrigeration conditions can be met, the return oil rate of the compressor 1 can be increased, the oil return rate of the compressor 1 can be ensured to be timely, and the crankshaft wear can be avoided.

[0068] Based on the above embodiments, the present invention further provides an air conditioning system, including a controller, and the controller is configured to be able to perform the control method described above. It can be understood by those skilled in the art that the present invention does not impose any restrictions on the specific structure and model of the controller, and the controller can be the original controller of the air conditioning system, or a controller separately set up to perform the control method of the present invention. The technician can set the structure and model of the controller according to actual use requirements.

[0069] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A control method for an air conditioning system, characterized in that: The air conditioning system includes a compressor and a gas-liquid separation device connected to each other in a main refrigerant circulation loop; When the air conditioning system is in cooling mode, the control method includes: Get the outdoor ambient temperature; According to the outdoor ambient temperature, the gas-liquid separation device is controlled to selectively adopt a centrifugal separation mode and / or a gravity separation mode to perform gas-liquid separation on the refrigerant.

2. The control method of the air conditioning system according to claim 1, characterized in that: The step of "controlling the gas-liquid separation device to selectively adopt a centrifugal separation mode and / or a gravity separation mode to perform gas-liquid separation on the refrigerant according to the outdoor ambient temperature" specifically includes: When the outdoor ambient temperature is less than or equal to the first preset outdoor ambient temperature, the gas-liquid separation device is controlled to perform gas-liquid separation on the refrigerant in a gravity separation mode.

3. The control method of the air conditioning system according to claim 1, characterized in that: The step of "controlling the gas-liquid separation device to selectively adopt a centrifugal separation mode and / or a gravity separation mode to perform gas-liquid separation on the refrigerant according to the outdoor ambient temperature" further includes: When the outdoor ambient temperature is greater than the first preset outdoor ambient temperature but less than or equal to the second preset outdoor ambient temperature, the gas-liquid separation device is controlled to perform gas-liquid separation on a portion of the refrigerant using a gravity separation mode and to perform gas-liquid separation on another portion of the refrigerant using a centrifugal separation mode.

4. The control method of the air conditioning system according to claim 3, characterized in that: The step of "controlling the gas-liquid separation device to perform gas-liquid separation on a portion of the refrigerant in a gravity separation mode and to perform gas-liquid separation on another portion of the refrigerant in a centrifugal separation mode" specifically includes: First, the gas-liquid separation device is controlled to perform gas-liquid separation on a part of the refrigerant in a gravity separation mode, and then the gas-liquid separation device is controlled to perform gas-liquid separation on another part of the refrigerant in a centrifugal separation mode; or The gas-liquid separation device is controlled to perform gas-liquid separation alternately by using a gravity separation mode for a portion of the refrigerant and by using a centrifugal separation mode for another portion of the refrigerant.

5. The control method of the air conditioning system according to claim 1, characterized in that: The step of "controlling the gas-liquid separation device to selectively adopt a centrifugal separation mode and / or a gravity separation mode to perform gas-liquid separation on the refrigerant according to the outdoor ambient temperature" further includes: When the outdoor ambient temperature is greater than a second preset outdoor ambient temperature, the gas-liquid separation device is controlled to perform gas-liquid separation on the refrigerant in a centrifugal separation mode.

6. The control method of the air conditioning system according to any one of claims 1 to 5, characterized in that: The gas-liquid separation device comprises a first shell, a second shell, a centrifugal separation assembly and a valve, wherein the first shell has a first chamber, a gravity separation zone is formed in the first chamber, the second shell is arranged in the first chamber, the second shell has a second chamber, a centrifugal separation zone is formed in the second chamber, the centrifugal separation assembly is arranged in the centrifugal separation zone, and the heat exchange device of the air conditioning system can be selectively connected with the gravity separation zone or the centrifugal separation zone by means of the valve; The control method of the gas-liquid separation device using the gravity separation mode to separate the refrigerant gas and liquid specifically includes: Controlling the heat exchange device to communicate with the gravity separation zone via the valve; The centrifugal separation component is controlled to be de-energized.

7. The control method of the air conditioning system according to claim 6, characterized in that: The first shell is provided with a first refrigerant inlet, a first refrigerant outlet and a first oil return port which are connected with the gravity separation area; “Controlling the heat exchange device to communicate with the gravity separation zone via the valve” specifically means: The heat exchange device is controlled to communicate with the first refrigerant inlet via the valve, the first refrigerant outlet is controlled to communicate with the air intake port of the compressor, and the first oil return port is controlled to communicate with the oil intake port of the compressor.

8. The control method of the air conditioning system according to claim 6, characterized in that: The control method of the gas-liquid separation device using the centrifugal separation mode to separate the refrigerant gas and liquid specifically includes: The heat exchange device controlling the air conditioning system is connected to the centrifugal separation area by means of the valve; The centrifugal separation component is controlled to be powered on and to work.

9. The control method of the air conditioning system according to claim 8, characterized in that: The second shell is provided with a second refrigerant inlet, a second refrigerant outlet and a second oil return port which are in communication with the centrifugal separation area; “Controlling the compressor to communicate with the centrifugal separation area” specifically means: The heat exchange device is controlled to communicate with the second refrigerant inlet via the valve, the second refrigerant outlet is controlled to communicate with the gravity separation area, and the second oil return port is controlled to communicate with the oil suction port of the compressor. 10 . An air conditioning system, comprising a controller, wherein the controller is configured to execute the control method according to claim 1 .

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