Air conditioning system and defrosting control method for air conditioning system

Abstract

The application discloses an air conditioning system and a defrosting control method of the air conditioning system, relates to the technical field of air conditioning, and can improve the comfort of users at least to a certain extent. The air conditioning system comprises a compressor, a first reversing component, a second reversing component, an indoor heat exchanger, an outdoor heat exchanger component and a bypass branch. The first reversing component has first to fourth valve ports, the first valve port is connected with an exhaust port, and the fourth valve port is connected with a suction port. The second reversing component has first to third ports, the first port is connected with the exhaust port, and the second port is connected with the suction port. The first end of the indoor heat exchanger is connected with the second valve port. The outdoor heat exchanger component comprises a first part and a second part, the first end of the first part is connected with the third valve port, the first end of the bypass branch is connected with the first end of the second part, and the second end of the bypass branch is connected to a pipeline between a first throttle valve and the second end of the first part. The air conditioning system is used for air conditioning.

Description

Technical Field

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

[0002] When an air conditioning system is operating in heating mode, frost will form on the outdoor heat exchanger assembly when the ambient temperature and humidity reach certain conditions. In related technologies, air conditioning systems use reverse defrosting to defrost the outdoor heat exchanger assembly. This method reverses the flow of the refrigerant used in heating, supplies the refrigerant discharged from the compressor to the outdoor heat exchanger assembly, and uses the heat from the compressor to defrost the outdoor heat exchanger assembly. During reverse defrosting, the air conditioning system stops heating the room and requires the indoor heat exchanger to absorb some heat from the room, lowering the indoor temperature, severely affecting indoor thermal comfort, and reducing the user experience. Summary of the Invention

[0003] Embodiments of the present invention provide an air-conditioning system and a defrost control method for the air-conditioning system, which can improve the defrost speed and reliability of the air-conditioning system at least to a certain extent.

[0004] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0005] A first embodiment of the present application provides an air-conditioning system, comprising: a compressor, a first reversing assembly, a second reversing assembly, an indoor heat exchanger, an outdoor heat exchanger assembly, and a bypass branch. The compressor has an intake port and an exhaust port; the first reversing assembly has first to fourth valve ports, the first valve port is connected to the exhaust port, the fourth valve port is connected to the intake port, the first valve port is in switching communication with one of the second valve port and the third valve port, and the fourth valve port is in switching communication with the other of the second valve port and the third valve port; the second reversing assembly has first to third ports, the first port is connected to the exhaust port, the second port is connected to the intake port, and the third port is in switching communication with one of the first port and the second port; the first end of the indoor heat exchanger is connected to the second valve port; the outdoor heat exchanger assembly includes a first part and a second part, the first end of the first part is connected to the third port, a first on-off valve is connected in series between the first end of the second part and the third valve port, a first throttle valve is connected between the second end of the first part and the second end of the indoor heat exchanger, and a second throttle valve is connected between the second end of the second part and the second end of the indoor heat exchanger; the first end of the bypass branch is connected to the first end of the second part, the second end of the bypass branch is connected to the pipeline between the first throttle valve and the second end of the first part, and the third throttle valve is connected in series on the bypass branch.

[0006] The air conditioning system provided by the embodiments of the present application comprises a first part and a second part which are arranged in parallel, when the first part is defrosted, the second reversing component is used to reverse a part of the refrigerant in the exhaust port of the bypass compressor to the first part for defrosting, at this time, the first part can be used as a condenser, and the second part can be used as an evaporator to continue to ensure the heating cycle of the air conditioning system; when the second part is defrosted, the latent heat of the high-pressure medium-temperature refrigerant flowing out of the indoor heat exchanger is used to defrost the second part, at this time, the second part can be used as a supercooling section, and the first part can be used as an evaporator to continue to ensure the heating cycle of the air conditioning system, so that the first part and the second part can be defrosted in turn, the heating state of the indoor heat exchanger to the indoor environment can be ensured, the temperature of the indoor environment can be prevented from being affected during the defrosting process of the air conditioning system, the indoor environment can be kept at a high temperature, and the comfort of the user can be improved. The high-temperature and high-pressure gaseous refrigerant discharged from the exhaust port of the compressor is used to defrost the first part, and the defrosting effect is remarkable. The high-pressure medium-temperature refrigerant flowing out of the indoor heat exchanger is used to defrost the second part, and the defrosting effect is remarkable. Therefore, by combining the high-pressure latent heat defrosting and the waste heat defrosting, the advantages of the waste heat defrosting and the high-pressure latent heat defrosting can be utilized, the problem of serious waste of the waste heat defrosting capacity and the problem of high cost and multiple pipelines of the high-pressure latent heat defrosting can be avoided, and then the defrosting speed and the reliability of the air conditioning system can be improved to a certain extent.

[0007] In some embodiments, the first part is located directly above the second part, or the first part is located directly below the second part.

[0008] In some embodiments, the first reversing component is a four-way reversing valve.

[0009] In some embodiments, the second reversing component is a three-way reversing valve or a four-way reversing valve; when the second reversing component is a four-way reversing valve, the second reversing component further comprises a fourth port, the fourth port is blocked, and the fourth port is in communication with the other one of the first port and the second port.

[0010] In some embodiments, the first throttling valve, the second throttling valve and the third throttling valve are all electronic expansion valves.

[0011] In some embodiments, the first part and the second part are two independent heat exchangers, or the first part and the second part are two parts of the same heat exchanger.

[0012] The second aspect embodiment of the present application provides a defrosting control method of an air conditioning system. The defrosting control method is applied to the air conditioning system. The defrosting control method comprises the following steps: when the air conditioning system is running in a heating mode, determining whether the air conditioning system meets a defrosting condition; if yes, controlling the air conditioning system to run in a first defrosting mode, in which one of the first part and the second part is defrosted; determining whether the air conditioning system meets a first defrosting mode end condition; if yes, controlling the air conditioning system to exit the first defrosting mode and run in a second defrosting mode, in which the other of the first part and the second part is defrosted; determining whether the air conditioning system meets a second defrosting mode end condition; if yes, controlling the air conditioning system to exit the second defrosting mode and run in the heating mode; wherein when the first part is defrosted, the third port is controlled to be conductive with the first port; the first throttling valve is fully opened, the second throttling valve is throttled, the first on-off valve is opened, and the third throttling valve is fully closed; when the second part is defrosted, the third port is controlled to be conductive with the second port, the first throttling valve is fully closed, the second throttling valve is fully opened, the first on-off valve is closed, and the third throttling valve is throttled.

[0013] The defrosting control method of the air conditioning system has the same beneficial effects as the air conditioning system, which will not be repeated here.

[0014] In some embodiments, before determining whether the air conditioning system meets the defrosting condition, the outdoor environment temperature Ta, the temperature Te1 of the second end of the first part, and the temperature Te2 of the second end of the second part are obtained; if Ta≤a, Te1 / Te2≤b, and the continuous running time of the air conditioning system in the heating mode reaches a first set time length, it is determined that the air conditioning system meets the defrosting condition.

[0015] In some embodiments, -7℃<a<7℃, -5℃≤b≤0℃, and the first set time length is greater than or equal to 10 minutes.

[0016] In some embodiments, in the first defrosting mode, the first part is defrosted, and in the second defrosting mode, the second part is defrosted; wherein the first defrosting mode end condition is that the temperature Te1 of the second end of the first part is greater than or equal to f and lasts for a first preset time; and / or the second defrosting mode end condition is that the temperature Te2 of the second end of the second part is greater than or equal to f and lasts for the first preset time.

[0017] In some embodiments, in the first defrosting mode, the second part is defrosted, and in the second defrosting mode, the first part is defrosted; wherein the first defrosting mode end condition is that the temperature Te2 of the second end of the second part is greater than or equal to f and lasts for a first preset time; and / or the second defrosting mode end condition is that the temperature Te1 of the second end of the first part is greater than or equal to f and lasts for the first preset time.

[0018] In some embodiments, 10℃≤f≤25℃, and / or, 5 seconds≤the first preset time≤30 seconds.

[0019] In some embodiments, the second throttle valve is adjustable, and the flow rate of the second throttle valve is adjusted to meet the first preset condition when defrosting the first part; the first preset condition is that the suction superheat degree of the compressor meets Tssh≥d, and the discharge superheat degree of the compressor meets Tdsh≥e; wherein, Tssh=Tg2-Tc_ps, Tg2 is the temperature of the first end of the second part, and Tc_ps is the saturation temperature corresponding to the suction pressure Ps at the suction port.

[0020] In some embodiments, the third throttle valve is adjustable, and the flow rate of the third throttle valve is adjusted to meet the second preset condition when defrosting the second part; the second preset condition is that the suction superheat degree of the compressor meets Tssh≥d, and the discharge superheat degree of the compressor meets Tdsh≥e; wherein, Tssh=Tg1-Tc_ps, Tg1 is the temperature of the first end of the first part, and Tc_ps is the saturation temperature corresponding to the suction pressure Ps at the suction port.

[0021] In some embodiments, 0℃≤d≤10℃, and 20℃≤e≤40℃. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 A schematic diagram of a composition of an air conditioning system according to the first embodiment of the present application is provided;

[0023] Figure 2 A schematic diagram of a composition of an air conditioning system according to the second embodiment of the present application is provided;

[0024] Figure 3 A schematic diagram of a refrigeration mode of the air conditioning system according to the first embodiment of the present application is provided;

[0025] Figure 4 A schematic diagram of a refrigeration mode of the air conditioning system according to the second embodiment of the present application is provided;

[0026] Figure 5 A schematic diagram of a heating mode of the air conditioning system according to the first embodiment of the present application is provided;

[0027] Figure 6 A schematic diagram of a heating mode of the air conditioning system according to the second embodiment of the present application is provided;

[0028] Figure 7 A schematic diagram of defrosting the first part of the air conditioning system according to the first embodiment of the present application is provided;

[0029] Figure 8The air conditioning system provided by the second embodiment of the present application provides a defrosting schematic diagram for the first part;

[0030] Figure 9 The air conditioning system provided by the first embodiment of the present application provides a defrosting schematic diagram for the second part;

[0031] Figure 10 The air conditioning system provided by the second embodiment of the present application provides a defrosting schematic diagram for the second part;

[0032] Figure 11 The flow chart of the first defrosting control method of the air conditioning system provided by the embodiment of the present application;

[0033] Figure 12 The flow chart of the second defrosting control method of the air conditioning system provided by the embodiment of the present application;

[0034] Figure 13 The composition schematic diagram of another air conditioning system provided by the embodiment of the present application;

[0035] Figure 14 The composition schematic diagram of another air conditioning system provided by the embodiment of the present application;

[0036] Figure 15 The composition schematic diagram of another air conditioning system provided by the embodiment of the present application.

[0037] Reference signs:

[0038] 100, air conditioning system; 101, control unit; 102, determination unit; 103, processing module; 1031, processor; 104, communication module; 1041, communication bus; 1042, communication interface; 105, storage module; 1051, memory; 1, compressor; 11, suction port; 111, suction pressure sensor; 12, discharge port; 121, discharge pressure sensor; 122, discharge temperature sensor; 2, first reversing assembly; 21, first valve port; 22, second valve port; 23, third valve port; 24, fourth valve port; 3, indoor heat exchanger; 31, first stop valve; 32, second stop valve; 4, outdoor heat exchanger assembly; 41, first part; 411, first part Te temperature sensor; 412, first part temperature sensor; 42, second part; 421, second part Te temperature sensor; 422, second part temperature sensor; 43, first throttling valve; 44, second throttling valve; 45, first on-off valve; 46, outdoor fan; 47, subcooler; 5, second reversing assembly; 51, first port; 52, second port; 53, third port; 6, bypass branch; 61, third throttling valve; 7, gas-liquid separator; 71, liquid inlet; 72, gas outlet; 8, oil-gas separator; 81, inlet; 82, gas discharge port; 83, oil return capillary; 84, oil outlet; 9, outdoor sensor. DETAILED DESCRIPTION

[0039] The embodiments of the present application will be described in detail below with reference to the drawings.

[0040] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0041] The terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0042] In the description of the present application, it is necessary to point out that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] The air conditioning system of the embodiment of the present application is described below.

[0044] Please refer to Figure 1 and Figure 2 , Figure 1 The composition schematic diagram of an air conditioning system provided by the first embodiment of the present application is shown in Figure 2 The composition schematic diagram of an air conditioning system provided by the second embodiment of the present application is shown in. The air conditioning system 100 provided by the embodiment of the present application comprises a compressor 1, a first reversing assembly 2, a second reversing assembly 5, an indoor heat exchanger 3, an outdoor heat exchanger assembly 4 and a bypass branch 6.

[0045] Please continue to refer to Figure 1 The compressor 1 has a suction port 11 and a discharge port 12. Specifically, the suction port 11 of the compressor 1 is used for suction, and the refrigerant enters the compression chamber of the compressor 1 through the suction port 11 for compression to form high-temperature and high-pressure refrigerant, and the high-temperature and high-pressure refrigerant gas is discharged from the discharge port 12 of the compressor 1 to the air conditioning system 100 for circulation of the refrigerant.

[0046] For example, the compressor 1 can be a scroll compressor, a rotor compressor, a screw compressor or other types of compressors.

[0047] Please continue to refer to Figure 1 The first reversing assembly 2 has a first valve port 21, a second valve port 22, a third valve port 23 and a fourth valve port 24. The first valve port 21 is connected with the discharge port 12. The fourth valve port 24 is connected with the suction port 11. The first valve port 21 can be reversely conducted with one of the second valve port 22 and the third valve port 23, and the fourth valve port 24 can be reversely conducted with the other one of the second valve port 22 and the third valve port 23. That is to say, when the first valve port 21 is conducted with the second valve port 22, the third valve port 23 is conducted with the fourth valve port 24; when the first valve port 21 is conducted with the third valve port 23, the second valve port 22 is conducted with the fourth valve port 24.

[0048] For example, the first reversing assembly 2 can be a four-way reversing valve. When the four-way reversing valve is powered on, the first valve port 21 is in communication with the second valve port 22, and the third valve port 23 is in communication with the fourth valve port 24. When the four-way reversing valve is powered off, the first valve port 21 is in communication with the third valve port 23, and the second valve port 22 is in communication with the fourth valve port 24. Of course, it can be understood that in other examples, when the four-way reversing valve is powered off, the first valve port 21 is in communication with the second valve port 22, and the third valve port 23 is in communication with the fourth valve port 24. When the four-way reversing valve is powered on, the first valve port 21 is in communication with the third valve port 23, and the second valve port 22 is in communication with the fourth valve port 24.

[0049] Please continue to refer to Figure 1 The second reversing assembly 5 has first to third ports 53. The first port 51 is connected to the exhaust port 12. The second port 52 is connected to the suction port 11. The third port 53 is in communication with one of the first port 51 and the second port 52. That is, the third port 53 can be in communication with the first port 51, and the third port 53 can also be in communication with the second port 52.

[0050] For example, the second reversing assembly 5 can be a three-way reversing valve or a four-way reversing valve. When the second reversing assembly 5 is a four-way reversing valve, the second reversing assembly 5 further includes a fourth port, which is closed and in communication with the other one of the first port 51 and the second port 52. When the three-way reversing valve or the four-way reversing valve is powered on, the first port 51 is in communication with the third port 53. When the three-way reversing valve or the four-way reversing valve is powered off, the second port 52 is in communication with the third port 53. Of course, it can be understood that in other examples, when the three-way reversing valve or the four-way reversing valve is powered on, the second port 52 is in communication with the third port 53. When the three-way reversing valve or the four-way reversing valve is powered off, the first port 51 is in communication with the third port 53.

[0051] Please continue to refer to Figure 1 The first end of the indoor heat exchanger 3 is connected to the second valve port 22.

[0052] Please continue to refer to Figure 1 The outdoor heat exchanger assembly 4 includes a first part 41 and a second part 42. The first end of the first part 41 is connected to the third port 53. Thus, the first end of the first part 41 can be in communication with the third port 53, and the communication between the first part 41 and the third port 53 can be controlled by the second reversing assembly 5, which is beneficial to improve the reliability of the air conditioning system 100.

[0053] Please continue to refer to Figure 1The first end of the second portion 42 is connected with the third valve port 23, and a first on-off valve 45 is connected in series between the two. Thus, the first end of the first portion 41 can be communicated with the third valve port 23, and the communication between the second portion 42 and the third valve port 23 can be controlled by the first on-off valve 45, which is beneficial to improve the reliability of the air conditioning system 100.

[0054] Please continue to refer to Figure 1 The second end of the first portion 41 and the second end of the indoor heat exchanger 3 are connected with a first throttling valve 43. The first throttling valve 43 can throttle and depress the refrigerant flowing therethrough. The first throttling valve 43 can also control the communication between the second end of the first portion 41 and the second end of the indoor heat exchanger 3. That is, the opening of the first throttling valve 43 is adjustable. The first throttling valve 43 can have a fully open state (the opening is 100%), a fully closed state (the opening is 0), and a throttling state (the opening is between 0 and 100%). In the fully closed state of the first throttling valve 43, the second end of the first portion 41 and the second end of the indoor heat exchanger 3 are not communicated. In the fully open state and the throttling state of the first throttling valve 43, the second end of the first portion 41 and the second end of the indoor heat exchanger 3 are communicated, and in the throttling state, the first throttling valve 43 can throttle and depress the refrigerant flowing therethrough.

[0055] The second end of the second portion 42 and the second end of the indoor heat exchanger 3 are connected with a second throttling valve 44. The second throttling valve 44 can throttle and depress the refrigerant flowing therethrough. The second throttling valve 44 can also control the communication between the second end of the second portion 42 and the second end of the indoor heat exchanger 3. That is, the opening of the second throttling valve 44 is adjustable. The second throttling valve 44 can have a fully open state (the opening is 100%), a fully closed state (the opening is 0), and a throttling state (the opening is between 0 and 100%). In the fully closed state of the second throttling valve 44, the second end of the second portion 42 and the second end of the indoor heat exchanger 3 are not communicated. In the fully open state and the throttling state of the first portion 41, the second end of the second portion 42 and the second end of the indoor heat exchanger 3 are communicated, and in the throttling state, the second throttling valve 44 can throttle and depress the refrigerant flowing therethrough.

[0056] Thus, the communication between the second end of the first portion 41 and the second end of the indoor heat exchanger 3 can be controlled by controlling the opening and closing of the first throttling valve 43, and the refrigerant flowing through the first throttling valve 43 can be throttled and depressed by controlling the opening degree of the first throttling valve 43. The communication between the second end of the second portion 42 and the second end of the indoor heat exchanger 3 can be controlled by controlling the opening and closing of the second throttling valve 44, and the refrigerant flowing through the first throttling valve 43 can be throttled and depressed by controlling the opening degree of the first throttling valve 43. Thus, it is beneficial to improve the stability and reliability of the air conditioning system 100.

[0057] Please continue to refer to Figure 3 The first end of the bypass branch 6 is connected to the first end of the second portion 42. The second end of the bypass branch 6 is connected to the pipeline between the first throttle valve 43 and the second end of the first portion 41. The third throttle valve 61 is connected in series on the bypass branch 6. The third throttle valve 61 can throttle and depress the refrigerant flowing therethrough. The third throttle valve 61 can also control the on-off between the first end of the second portion 42 and the second end of the first portion 41. That is, the third throttle valve 61 can be adjusted in opening degree. The third throttle valve 61 can have a fully open state (opening degree of 100%), a fully closed state (opening degree of 0) and a throttling state (opening degree between 0-100%). In the fully closed state of the third throttle valve 61, the first end of the second portion 42 and the second end of the first portion 41 are not connected. In the fully open state and the throttling state of the first portion 41, the first end of the second portion 42 and the second end of the first portion 41 are connected, and in the throttling state, the third throttle valve 61 can throttle and depress the refrigerant flowing therethrough.

[0058] The air conditioning system 100 according to the embodiments of the present application has a cooling mode, a heating mode and a defrosting mode. The control process and the flow direction of the refrigerant in the cooling mode, the heating mode and the defrosting mode of the embodiments of the present application are described in detail below.

[0059] Cooling mode

[0060] Please refer to Figure 4 and Figure 3 , Figure 4 the schematic diagram of the cooling mode of the air conditioning system provided by the first embodiment of the present application, Figure 5 the schematic diagram of the cooling mode of the air conditioning system provided by the second embodiment of the present application. When the air conditioning system 100 is in the cooling mode, the first valve port 21 and the third valve port 23 of the first reversing assembly 2 are connected, the second valve port 22 and the fourth valve port 24 are connected, the first port 51 and the third port 53 of the second reversing assembly 5 are connected, the first on-off valve 45 is open, the first throttle valve 43 is throttled, the second throttle valve 44 is throttled, and the third throttle valve 61 is fully closed.

[0061] Refrigerant Flow: The high-temperature, high-pressure gaseous refrigerant discharged from the exhaust port 12 of the compressor 1 flows to the first reversing assembly 2 and the second reversing assembly 5, respectively. The refrigerant flowing into the first reversing assembly 2 flows through the first valve port 21 and into the first reversing assembly 2, and then flows out of the first reversing assembly 2 through the third valve port 23. The refrigerant flowing out of the third valve port 23 flows to the second portion 42, where it undergoes sufficient heat exchange and becomes a high-pressure, subcooled liquid refrigerant. The refrigerant flowing out of the second portion 42 then passes through the second throttle valve 44 for throttling and pressure reduction. The refrigerant flowing into the second reversing assembly 5 flows through the first port 51 and into the second reversing assembly 5, and then flows out of the second reversing assembly 5 through the third port 53. The refrigerant flowing out of the third port 53 flows to the first portion 41, where it undergoes sufficient heat exchange and becomes a high-pressure, subcooled liquid refrigerant. The refrigerant flowing out of the first portion 41 then passes through the first throttle valve 43 for throttling and pressure reduction. The refrigerant after throttling and reducing the pressure by the first throttle valve 43 and the refrigerant after throttling and reducing the pressure by the second throttle valve 44 flow into the indoor heat exchanger 3, and after heat exchange in the indoor heat exchanger 3, it becomes a low-temperature and low-pressure superheated gaseous refrigerant, and finally flows back to the intake port 11 of the compressor 1 through the second valve port 22 and the fourth valve port 24 in turn, thereby completing the refrigeration cycle of the air-conditioning system 100.

[0062] Heating mode

[0063] See also Figure 6 and Figure 5 , Figure 6 This is a schematic diagram of the heating mode of the air-conditioning system provided in the first embodiment of the present application. Figure 7 This is a schematic diagram of the heating mode of the air conditioning system provided by the second embodiment of the present application. When the air conditioning system 100 is in heating mode, the first valve port 21 of the first reversing assembly 2 is connected to the second valve port 22, the third valve port 23 is connected to the fourth valve port 24, the second port 52 of the second reversing assembly 5 is connected to the third port 53, the first on-off valve 45 is open, the first throttle valve 43 is throttled, the second throttle valve 44 is throttled, and the third throttle valve 61 is fully closed.

[0064] The high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows into the first reversing assembly 2 through the first valve port 21 and flows out of the first reversing assembly 2 from the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3, and becomes high-temperature and high-pressure liquid refrigerant after heat exchange in the indoor heat exchanger 3, and then flows out of the indoor heat exchanger 3 and flows to the first throttling valve 43 and the second throttling valve 44, respectively. The refrigerant throttled and depressurized by the first throttling valve 43 flows into the first part 41 and evaporates into low-temperature and low-pressure superheated gaseous refrigerant in the first part 41. The refrigerant throttled and depressurized by the second throttling valve 44 flows into the second part 42 and evaporates into low-temperature and low-pressure superheated gaseous refrigerant in the second part 42. Finally, the refrigerant flowing out of the first part 41 flows back to the suction port 11 of the compressor 1 through the third port 53 and the second port 52 in turn, and the refrigerant flowing out of the second part 42 flows back to the suction port 11 of the compressor 1 through the third valve port 23 and the fourth valve port 24 in turn, thus completing the heating cycle of the air conditioning system 100.

[0065] Defrosting mode

[0066] Please refer to Figure 8 and Figure 7 , Figure 8 The air conditioning system provided in the first embodiment of the present application is shown in the following figure for defrosting the first part. Figure 9 The air conditioning system provided in the second embodiment of the present application is shown in the following figure for defrosting the first part. When defrosting the first part 41, the first valve port 21 and the second valve port 22 of the first reversing assembly 2 are controlled to be conductive, the third valve port 23 and the fourth valve port 24 are controlled to be conductive, the third port 53 and the first port 51 of the second reversing assembly 5 are controlled to be conductive, the first throttling valve 43 is controlled to be fully open, the second throttling valve 44 is controlled to be throttled, the first on-off valve 45 is controlled to be open, and the third throttling valve 61 is controlled to be fully closed.

[0067] The refrigerant flows from the discharge port 12 of the compressor 1 to the first reversing assembly 2 and the second reversing assembly 5. The refrigerant flowing to the second reversing assembly 5 flows into the second reversing assembly 5 through the first port 51 and flows out of the second reversing assembly 5 from the third port 53. The refrigerant flowing out of the third port 53 flows to the first part 41, and frost on the first part 41 is removed by the high-temperature and high-pressure superheated gaseous refrigerant discharged from the compressor 1. After defrosting, the high-temperature and high-pressure superheated gaseous refrigerant becomes subcooled liquid refrigerant, flows to the second part 42 through the first throttling valve 43, and becomes low-temperature and low-pressure superheated gaseous refrigerant after evaporation in the second part 42, and then flows out of the second part 42. The refrigerant flowing to the first reversing assembly 2 flows into the first reversing assembly 2 through the first valve port 21 and flows out of the first reversing assembly 2 from the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3, becomes high-temperature and high-pressure liquid refrigerant after heat exchange in the indoor heat exchanger 3, and then flows out of the indoor heat exchanger 3 to the second throttling valve 44. The refrigerant throttled and depressurized by the second throttling valve 44 flows into the second part 42 and evaporates into low-temperature and low-pressure superheated gaseous refrigerant in the second part 42, and then flows out of the second part 42. Finally, the refrigerant flowing out of the second part 42 flows back to the suction port 11 of the compressor 1 through the third valve port 23 and the fourth valve port 24 in sequence, and the defrosting of the refrigerant in the first part 41 is completed.

[0068] Please refer to Figure 10 and Figure 9 , Figure 10 the schematic diagram of the air conditioning system provided by the first embodiment of the present application for defrosting the second part, Figure 9 the schematic diagram of the air conditioning system provided by the second embodiment of the present application for defrosting the second part. When defrosting the second part 42, the first valve port 21 and the second valve port 22 of the first reversing assembly 2 are controlled to be conductive, the third valve port 23 and the fourth valve port 24 are controlled to be conductive, the second port 52 and the third port 53 of the second reversing assembly 5 are controlled to be conductive, the first throttling valve 43 is controlled to be fully closed, the second throttling valve 44 is controlled to be fully open, the first on-off valve 45 is controlled to be closed, and the third throttling valve 61 is throttled.

[0069] The high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows into the first reversing assembly 2 through the first valve port 21 and flows out of the first reversing assembly 2 from the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3. The high-temperature and high-pressure gaseous refrigerant is incompletely heat-exchanged in the indoor heat exchanger 3 and becomes high-temperature and high-pressure subcooled liquid refrigerant or two-phase refrigerant with small supercooling degree after heat-exchange. The refrigerant flows out of the indoor heat exchanger 3 and flows to the second throttling valve 44, then flows to the second part 42 after passing through the second throttling valve 44, and then defrosts the second part 42 by using the waste heat of the high-temperature and high-pressure subcooled liquid refrigerant (waste heat is sensible heat) or high-temperature and high-pressure two-phase refrigerant (waste heat is sensible heat plus latent heat) flowing out of the indoor heat exchanger 3. The refrigerant after defrosting the second part 42 flows to the bypass branch 6, then flows to the third throttling valve 61 on the bypass branch 6, becomes low-temperature and low-pressure two-phase refrigerant after throttling and pressure reduction by the third throttling valve 61, then flows into the first part 41 again, and evaporates into low-temperature and low-pressure superheated gaseous refrigerant in the first part 41. Finally, the refrigerant flowing out of the first part 41 flows back to the suction port 11 of the compressor 1 through the second port 52 and the third port 53 in sequence, and the defrosting refrigerant circulation of the second part 42 is completed.

[0070] Therefore, by arranging the outdoor heat exchanger assembly 4 to include the first part 41 and the second part 42 in parallel, when defrosting the first part 41, the air conditioning system 100 reverses part of the refrigerant flowing out of the discharge port 12 of the compressor 1 to the first part 41 by using the second reversing assembly 5 to defrost the first part 41. At this time, the first part 41 can act as a condenser, and the second part 42 can act as an evaporator to continue to ensure the heating cycle of the air conditioning system 100. When defrosting the second part 42, the air conditioning system 100 can defrost the second part 42 by using the latent heat of the high-pressure medium-temperature refrigerant flowing out of the indoor heat exchanger 3. At this time, the second part 42 can act as a subcooling section, and the first part 41 can act as an evaporator to continue to ensure the heating cycle of the air conditioning system 100. Thus, the first part 41 and the second part 42 can be defrosted in turn while still ensuring the heating state of the indoor heat exchanger 3 to the indoor, which can avoid affecting the indoor temperature during the defrosting process of the air conditioning system 100, so that the indoor can maintain a high temperature, which is conducive to improving the comfort of the user. Moreover, the first part 41 is defrosted by using the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1, which has a remarkable defrosting effect. The second part 42 is defrosted by using the high-pressure medium-temperature refrigerant flowing out of the indoor heat exchanger 3, which has a remarkable defrosting effect. Thus, by combining high-pressure latent heat defrosting and waste heat defrosting, the advantages of waste heat defrosting and high-pressure latent heat defrosting can be utilized, while the problems of serious waste of waste heat defrosting ability and high cost of high-pressure latent heat defrosting can be avoided, and thus the defrosting speed and reliability of the air conditioning system 100 can be improved to a certain extent.

[0071] Please continue to refer to Figure 10 , the first part 41 can be located directly above the second part 42. As Figure 9 shown, the first part 41 can also be located directly below the second part 42. In this way, the bypass branch 6 can be reasonably arranged, which is conducive to reducing the cost.

[0072] Please refer to Figure 9 , the first throttle valve 43, the second throttle valve 44 and the third throttle valve 61 can be electronic expansion valves. In this way, the running speed and accuracy of the air conditioning system 100 can be improved. In other embodiments, the first throttle valve 43, the second throttle valve 44 and the third throttle valve 61 can also be thermal expansion valves.

[0073] In some embodiments, the first part 41 and the second part 42 can be divided into two independent heat exchangers. In this way, when one of the first part 41 and the second part 42 is damaged when the air conditioning system 100 is in cooling or heating mode, the air conditioning system 100 can be prevented from stopping working, thereby improving the stability and reliability of the air conditioning system 100.

[0074] In other embodiments, the first part 41 and the second part 42 can also be divided into two parts of the same heat exchanger. In this way, the assembly of the air conditioning system 100 is facilitated, thereby improving the assembly efficiency of the air conditioning system 100.

[0075] In some embodiments, the first on-off valve 45 can be a two-way valve. In this way, the response speed and reliability of the air conditioning system 100 can be improved.

[0076] Please continue to refer to Figure 9 , the first throttle valve 43 and the second throttle valve 44 are connected to the second end of the indoor heat exchanger 3 through the same subcooler 47. By arranging the subcooler 47, the flash gas generated during throttling of the air conditioning system 100 can be reduced, which is conducive to improving the refrigerating capacity of the air conditioning system 100 and the stability of the operation of the compressor 1, thereby improving the stability and reliability of the air conditioning system 100.

[0077] Please continue to refer to Figure 9 , the first end of the indoor heat exchanger 3 is connected with the first stop valve 31, and the second end of the indoor heat exchanger 3 is connected with the second stop valve 32. In this way, by arranging the first stop valve 31 and the second stop valve 32, the air conditioning system 100 can be conveniently maintained and repaired. Specifically, when the indoor heat exchanger 3 needs to be repaired or replaced, the first stop valve 31 and the second stop valve 32 can be closed, so that the indoor heat exchanger 3 can be more conveniently repaired without discharging the refrigerant of the entire air conditioning system 100.

[0078] Exemplarily, the air conditioning system 100 can be a multi-connected system. The air conditioning system 100 comprises a plurality of indoor units. Each indoor unit is provided with an indoor heat exchanger 3. The plurality of indoor units are connected in parallel. The first end of the indoor heat exchanger 3 of each indoor unit can be connected to the first stop valve 31. The second end of the indoor heat exchanger 3 of each indoor unit can be connected to the second stop valve 32. It can be understood that, in other examples, the air conditioning system 100 can comprise only one indoor unit.

[0079] Please continue to refer to Figure 9 In some embodiments, the air conditioning system 100 further comprises a gas-liquid separator 7. The gas-liquid separator 7 is arranged between the compressor 1 and the first reversing assembly 2. The gas-liquid separator 7 has a liquid inlet 71 and a gas outlet 72. The liquid inlet 71 is connected to the fourth valve port 24. The gas outlet 72 is connected to the suction port 11. By arranging the gas-liquid separator 7, the refrigerant entering the compressor 1 can be subjected to gas-liquid separation, avoiding liquid impact on the compressor 1, thereby facilitating protection of the compressor 1.

[0080] Please continue to refer to Figure 9 In some embodiments, the air conditioning system 100 further comprises an oil-gas separator 8. The oil-gas separator 8 is arranged between the compressor 1 and the first reversing assembly 2. The oil-gas separator 8 has an inlet 81, a gas discharge port 82 and an oil outlet 84. The inlet 81 is connected to the exhaust port 12. The gas discharge port 82 is connected to the first valve port 21. The oil outlet 84 is connected to the suction port 11. By arranging the oil-gas separator 8, the protection of the compressor 1 can be improved, thereby facilitating the stability and reliability of the air conditioning system 100.

[0081] Please continue to refer to Figure 9 In some embodiments, the air conditioning system 100 further comprises an oil return capillary tube 83. The oil return capillary tube 83 is located between the compressor 1 and the oil outlet 84 of the oil-gas separator 8. The oil return capillary tube 83 can return the liquid separated from the oil-gas separator 8 to the suction port 11 of the compressor 1.

[0082] Please continue to refer to Figure 11 In some embodiments, one side of the outdoor heat exchanger assembly 4 can be provided with an outdoor fan 46. This arrangement can improve the heat exchange efficiency of the outdoor heat exchanger assembly 4.

[0083] Based on the structure of the air conditioning system 100 described above, there are two defrosting methods for the air conditioning system 100 of the embodiments of the present application. The defrosting control method of the air conditioning system 100 of the first embodiment of the present application will be described below.

[0084] Please refer to Figure 11 , Figure 10A flow chart of a first defrosting control method of an air conditioning system according to an embodiment of the present application is provided. The defrosting control method of the air conditioning system 100 comprises the following steps:

[0085] S1: When the air conditioning system 100 is running in the heating mode, it is determined whether the air conditioning system 100 meets the defrosting condition. When the air conditioning system 100 is in the heating mode, the first valve port 21 and the second valve port 22 of the first reversing component 2 are in communication, the third valve port 23 and the fourth valve port 24 are in communication, the second port 52 and the third port 53 of the second reversing component 5 are in communication, the first on-off valve 45 is open, the first throttling valve 43 is throttled, the second throttling valve 44 is throttled, and the third throttling valve 61 is fully closed.

[0086] S2: If the air conditioning system 100 meets the defrosting condition, the third port 53 and the first port 51 of the second reversing component 5 are in communication, and the first throttling valve 43 is fully opened, so that the air conditioning system 100 runs in the first defrosting mode to defrost the first part 41.

[0087] Thus, in the first defrosting mode, the first valve port 21 and the second valve port 22 of the first reversing component 2 are in communication, the third valve port 23 and the fourth valve port 24 are in communication, the third port 53 and the first port 51 of the second reversing component 5 are in communication, the first throttling valve 43 is fully opened, the second throttling valve 44 is throttled, the first on-off valve 45 is open, and the third throttling valve 61 is fully closed. At this time, the flow direction of the refrigerant in the first defrosting mode can be: the high-temperature and high-pressure gaseous refrigerant discharged from the exhaust port 12 of the compressor 1 flows to the first reversing component 2 and the second reversing component 5, respectively, the refrigerant flowing to the second reversing component 5 flows into the second reversing component 5 through the first port 51 and flows out of the second reversing component 5 from the third port 53. The refrigerant flowing out of the third port 53 flows to the first part 41, and the frost on the first part 41 is removed by the high-temperature and high-pressure superheated gaseous refrigerant discharged from the compressor 1. After defrosting, the high-temperature and high-pressure superheated gaseous refrigerant becomes a supercooled liquid refrigerant, flows to the second part 42 through the first throttling valve 43, and becomes a low-temperature and low-pressure superheated gaseous refrigerant after evaporation in the second part 42, and then flows out of the second part 42. The refrigerant flowing to the first reversing component 2 flows into the first reversing component 2 through the first valve port 21 and flows out of the first reversing component 2 from the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3, and becomes a high-temperature and high-pressure liquid refrigerant after heat exchange in the indoor heat exchanger 3, and then flows out of the indoor heat exchanger 3 to the second throttling valve 44. The refrigerant flowing into the second part 42 after pressure reduction by the second throttling valve 44 evaporates into a low-temperature and low-pressure superheated gaseous refrigerant in the second part 42, and then flows out of the second part 42. Finally, the refrigerant flowing out of the second part 42 flows back to the suction port 11 of the compressor 1 through the third valve port 23 and the fourth valve port 24 in turn.

[0088] S3: determining whether the air conditioning system 100 meets the first defrost mode end condition;

[0089] S4: if the air conditioning system 100 meets the first defrost mode end condition, controlling the second port 52 and the third port 53 of the second reversing component 5 to be conductive, controlling the first throttling valve 43 to be fully closed, the second throttling valve 44 to be fully opened, the first on-off valve 45 to be closed, and the third throttling valve 61 to be throttled, so as to control the air conditioning system 100 to exit the first defrost mode and run the second defrost mode, in which the second part 42 is defrosted.

[0090] Thus, in the second defrost mode, the first valve port 21 and the second valve port 22 of the first reversing component 2 are kept conductive, the third valve port 23 and the fourth valve port 24 are kept conductive, the second port 52 and the third port 53 of the second reversing component 5 are controlled to be conductive, the first throttling valve 43 is controlled to be fully closed, the second throttling valve 44 is controlled to be fully opened, the first on-off valve 45 is controlled to be closed, and the third throttling valve 61 is controlled to be throttled. At this time, the flow direction of the refrigerant in the second defrost mode can be: the high-temperature and high-pressure gaseous refrigerant discharged from the exhaust port 12 of the compressor 1 flows into the first reversing component 2 through the first valve port 21 and flows out of the first reversing component 2 from the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3, and the high-temperature and high-pressure gaseous refrigerant is incompletely heat-exchanged in the indoor heat exchanger 3, and becomes high-temperature and high-pressure subcooled liquid refrigerant or two-phase refrigerant with small supercooling degree after heat exchange (the waste heat is sensible heat plus latent heat), the waste heat defrosts the second part 42, and the refrigerant after defrosting the second part 42 flows to the bypass branch 6, then flows to the third throttling valve 61 on the bypass branch 6, becomes low-temperature and low-pressure two-phase refrigerant after throttling and pressure reduction through the third throttling valve 61, then flows into the first part 41 again, and evaporates into low-temperature and low-pressure superheated gaseous refrigerant in the first part 41, and finally the refrigerant flowing out of the first part 41 flows back to the suction port 11 of the compressor 1 through the second port 52 and the third port 53 in turn.

[0091] S5: determining whether the air conditioning system 100 meets the second defrost mode end condition;

[0092] S6: if the second defrost mode end condition is met, controlling the first throttling valve 43 to be throttled, the second throttling valve 44 to be throttled, the first on-off valve 45 to be opened, and the third throttling valve 61 to be fully closed, so as to exit the second defrost mode and run the heating mode.

[0093] Therefore, when switching from the heating mode to the first defrosting mode and the second defrosting mode for defrosting the first portion 41 and the second portion 42, the first reversing component 2 is always not reversed, the power consumption of the air conditioning system 100 can be reduced, the air conditioning system 100 can realize uninterrupted heating, the indoor environment can always be kept at a high temperature, and the comfort of the user can be improved. At the same time, the first defrosting mode uses the high-temperature and high-pressure gaseous refrigerant discharged from the exhaust port 12 of the compressor 1 to defrost the first portion 41, and the defrosting effect is remarkable. The second defrosting mode uses the high-pressure and medium-temperature refrigerant flowing out of the indoor heat exchanger 3 to defrost the second portion 42, and through the combination of high-pressure latent defrosting and waste heat defrosting, the advantages of waste heat defrosting and high-pressure latent defrosting can be utilized, and the problems of serious waste of waste heat defrosting capacity and high cost of high-pressure latent defrosting can be avoided, which is beneficial to improve the reliability and stability of the operation of the air conditioning system 100.

[0094] In addition, when the first portion 41 is located directly above the second portion 42, during the defrosting process of the outdoor heat exchanger assembly 4, the first portion 41 is defrosted first, and then the second portion 42 is defrosted after the defrosting of the first portion 41 is completed, which is beneficial to ensure the defrosting effect of the outdoor heat exchanger assembly 4 and prevent the problem that when the first portion 41 is defrosted first and then the second portion 42 is defrosted, the defrosting water of the first portion 41 falls on the second portion 42 as an evaporator, which causes the second portion 42 to freeze and results in poor defrosting effect of the second portion 42.

[0095] In some embodiments, in order to improve the evaporation capacity of the first portion 41, the outdoor fan 46 is arranged on the side of the first portion 41 away from the second portion 42, and in step S4, if the air conditioning system 100 satisfies the first defrosting mode ending condition, the outdoor fan 46 is turned on, so that air can be supplied to the first portion 41. In this way, after the defrosting of the first portion 41 is completed, the outdoor fan 46 is turned on to improve the evaporation capacity of the first portion 41, and thus the suction pressure of the compressor 1 can be improved, so that air can be quickly discharged on the indoor side after the defrosting of the air conditioning system 100 is completed, which is beneficial to improve the user experience.

[0096] In some embodiments, a fourth throttling valve can be arranged on the pipeline between the indoor heat exchanger 3 and the outdoor heat exchanger assembly 4. When the air conditioning system 100 is in the cooling mode, the heating mode, and the defrosting of the first portion 41, the fourth throttling valve is throttled. When the air conditioning system 100 defrosts the second portion 42, the fourth throttling valve is throttled.

[0097] In some embodiments, the outdoor environment temperature Ta, the temperature Te1 of the second end of the first portion 41, and the temperature Te2 of the second end of the second portion 42 are obtained before it is determined that the air conditioning system 100 meets the defrosting condition. If Ta≤a, Te1 / Te2≤b, and the continuous operation time of the air conditioning system 100 in the heating mode reaches the first set time length, it is determined that the air conditioning system meets the defrosting condition. In this way, the air conditioning system 100 can accurately determine whether to defrost, which is conducive to improving the sensitivity and reliability of the defrosting of the air conditioning system 100.

[0098] For example, in the embodiments described above, Figure 10 In the embodiments described above, an outdoor temperature sensor 9 can be arranged on the outside of the air conditioning system 100 to obtain the outdoor environment temperature Ta. A first portion Te temperature sensor 411 can be arranged at the second end of the first portion 41 to obtain the temperature Te1 of the second end of the first portion 41. A second portion Te temperature sensor 421 can be arranged at the second end of the second portion 42 to obtain the temperature Te2 of the second end of the second portion 42.

[0099] In some embodiments, -7℃≤a≤7℃. For example, the threshold value a of the outdoor environment temperature Ta can be -6℃, -5℃, -4℃, -3℃, -2℃, -1℃, 0℃, 1℃, 2℃, 3℃, 4℃, 5℃, or 6℃, etc.

[0100] In some embodiments, -5℃≤b≤0℃. For example, the ratio Te1 / Te2 can be -5℃, -4℃, -3℃, -2℃, -1℃, or 0℃, etc.

[0101] In some embodiments, the first set time length≥10min. For example, the first set time length can be 10min, 11min, 12min, 13min, or 14min, etc.

[0102] In some embodiments, the first defrosting mode end condition is that the temperature Te1 of the second end of the first portion 41≥f and lasts for a first preset time. In this way, the first defrosting mode can be exited in time when the first defrosting mode end condition is met, which is conducive to improving the intelligent degree and reliability of the air conditioning system 100.

[0103] In some embodiments, the second defrosting mode end condition is that the temperature Te2 of the second end of the second portion 42≥f and lasts for a first preset time. In this way, the second defrosting mode can be exited in time when the second defrosting mode end condition is met, which is conducive to improving the intelligent degree and reliability of the air conditioning system 100.

[0104] In some embodiments, 10℃≤f≤25℃. For example, the temperature f of the second end of the second portion 42 can be 10℃, 11℃, 12℃, 13℃, 14℃, 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃ or 25℃, etc.

[0105] In some embodiments, 5 seconds≤the first preset time≤30 seconds. For example, the first preset time can be 5 seconds, 10 seconds, 15 seconds, 20 seconds, 25 seconds or 30 seconds, etc.

[0106] In some embodiments, the opening of the second throttle valve 44 is adjustable. When defrosting the first portion 41, the opening of the second throttle valve 44 is adjusted to meet the first preset condition. The first preset condition is that the suction superheat degree of the compressor 1 meets Tssh≥d, and the discharge superheat degree of the compressor 1 meets Tdsh≥e; wherein Tssh=Tg2-Tc_ps, Tg2 is the temperature of the first end of the second portion 42, and Tc_ps is the saturation temperature corresponding to the suction pressure Ps at the suction port 11. In this way, the accuracy of the opening control of the second throttle valve 44 can be improved, thereby facilitating the improvement of the reliability of the air conditioning system 100. It should be noted that Tdsh=Td-Tc_pd, Td is the temperature of the discharge port 12 of the compressor 1, and Tc_pd is the saturation temperature corresponding to the discharge pressure Pd at the discharge port 12.

[0107] For example, in the above-mentioned embodiments, Figure 10 In the above-mentioned embodiments, a second portion temperature sensor 422 can be arranged at the first end of the second portion 42 to obtain the temperature Tg2 of the first end of the second portion 42, a suction pressure sensor 111 can be arranged at the suction port 11 of the compressor 1 to detect the suction pressure Ps, and a discharge pressure sensor 121 can be arranged at the discharge port 12 of the compressor 1 to detect the discharge pressure Pd. A discharge temperature sensor 122 can be arranged at the discharge port 12 of the compressor 1 to detect the discharge temperature Td.

[0108] In some embodiments, the opening of the third throttle valve 61 is adjustable, and when defrosting the second portion 42, the opening of the third throttle valve 61 is adjusted to meet the second preset condition. The second preset condition is that the suction superheat degree of the compressor 1 meets Tssh≥d, and the discharge superheat degree of the compressor 1 meets Tdsh≥e. Wherein Tssh=Tg1-Tc_ps, Tg1 is the temperature of the first end of the first portion 41, and Tc_ps is the saturation temperature corresponding to the suction pressure Ps at the suction port 11.

[0109] For example, in the above-mentioned embodiments, Figure 12In the embodiment, a first portion temperature sensor 412 is arranged at the first end of the first portion 41 to obtain the temperature Tg1 of the first end of the first portion 41.

[0110] In some embodiments, 0℃≤d≤10℃. For example, d can be 0℃, 1℃, 2℃, 3℃, 4℃, 5℃, 6℃, 7℃, 8℃, 9℃ or 10℃.

[0111] In some embodiments, 20℃≤e≤40℃. For example, e can be 20℃, 25℃, 30℃, 35℃ or 40℃.

[0112] In some embodiments, when defrosting the second portion 42, the indoor fan of the air conditioning system 100 is controlled to stop running or run at the lowest wind stop. This setting can ensure that the refrigerant flowing into the second portion 42 has residual heat in the second defrosting mode, thereby ensuring the defrosting efficiency of the second portion 42.

[0113] The defrosting control method of the air conditioning system 100 of the second embodiment of the present application will be described below.

[0114] Please refer to Figure 12 , Figure 10 The flow chart of the second defrosting control method of the air conditioning system provided by the embodiment of the present application. The defrosting control method of the air conditioning system 100 includes the following steps:

[0115] S1: When the air conditioning system 100 runs in the heating mode, it is determined whether the air conditioning system 100 meets the defrosting condition. When the air conditioning system 100 is in the heating mode, the first valve port 21 and the second valve port 22 of the first reversing component 2 are conductive, the third valve port 23 and the fourth valve port 24 are conductive, the second port 52 and the third port 53 of the second reversing component 5 are conductive, the first on-off valve 45 is open, the first throttling valve 43 is throttled, the second throttling valve 44 is throttled, and the third throttling valve 61 is fully closed.

[0116] S2: If the air conditioning system 100 meets the defrosting condition, the first throttling valve 43 is controlled to be fully closed, the second throttling valve 44 is controlled to be fully open, the first on-off valve 45 is controlled to be closed, and the third throttling valve 61 is controlled to be throttled, so that the air conditioning system 100 runs in the first defrosting mode to defrost the second portion 42.

[0117] Thus, in the first defrosting mode, the first valve port 21 and the second valve port 22 of the first reversing component 2 are kept open, the third valve port 23 and the fourth valve port 24 are kept open, the second port 52 and the third port 53 of the second reversing component 5 are controlled to be open, the first throttle valve 43 is controlled to be fully closed, the second throttle valve 44 is controlled to be fully open, the first on-off valve 45 is controlled to be closed, and the third throttle valve 61 is controlled to be throttled. At this time, the flow direction of the refrigerant in the first defrosting mode can be: the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows into the first reversing component 2 through the first valve port 21 and flows out of the first reversing component 2 from the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3, and the high-temperature and high-pressure gaseous refrigerant is incompletely heat-exchanged in the indoor heat exchanger 3, and becomes high-temperature and high-pressure subcooled liquid refrigerant or two-phase refrigerant with small supercooling degree after heat exchange, and flows to the second throttle valve 44 after flowing out of the indoor heat exchanger 3, flows to the second part 42 after passing through the second throttle valve 44, and then defrosts the second part 42 by using the waste heat of the high-temperature and high-pressure subcooled liquid refrigerant (waste heat is sensible heat) or high-temperature and high-pressure two-phase refrigerant (waste heat is sensible heat plus latent heat) flowing out of the indoor heat exchanger 3, and the refrigerant defrosted in the second part 42 flows to the bypass branch 6, and then flows to the third throttle valve 61 on the bypass branch 6, and becomes low-temperature and low-pressure two-phase refrigerant after being throttled and depressurized by the third throttle valve 61, and then flows into the first part 41 again, and evaporates into low-temperature and low-pressure superheated gaseous refrigerant in the first part 41, and finally the refrigerant flowing out of the first part 41 flows back to the suction port 11 of the compressor 1 in sequence through the second port 52 and the third port 53.

[0118] S3: determining whether the air conditioning system 100 meets the first defrosting mode end condition;

[0119] S4: if the air conditioning system 100 meets the first defrosting mode end condition, the third port 53 and the first port 51 of the second reversing component 5 are kept open, the first throttle valve 43 is controlled to be fully open, the second throttle valve 44 is controlled to be throttled, the first on-off valve 45 is controlled to be opened, and the third throttle valve 61 is controlled to be fully closed, so as to control the air conditioning system 100 to exit the first defrosting mode and run in the second defrosting mode, and defrost the first part 41 in the second defrosting mode.

[0120] Thus, in the second defrosting mode, the first valve port 21 and the second valve port 22 of the first reversing assembly 2 are kept open, the third valve port 23 and the fourth valve port 24 are kept open, the third port 53 and the first port 51 of the second reversing assembly 5 are kept open, the first throttle valve 43 is controlled to be fully open, the second throttle valve 44 is throttled, the first on-off valve 45 is open, and the third throttle valve 61 is controlled to be fully closed. At this time, the flow direction of the refrigerant in the second defrosting mode can be: the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows to the first reversing assembly 2 and the second reversing assembly 5 respectively, the refrigerant flowing to the second reversing assembly 5 flows into the second reversing assembly 5 through the first port 51, and flows out of the second reversing assembly 5 from the third port 53. The refrigerant flowing out of the third port 53 flows to the first part 41, and the frost on the first part 41 is removed by the high-temperature and high-pressure superheated gaseous refrigerant discharged from the compressor 1. After defrosting, the high-temperature and high-pressure superheated gaseous refrigerant becomes subcooled liquid refrigerant, flows to the second part 42 through the first throttle valve 43, and becomes low-temperature and low-pressure superheated gaseous refrigerant after evaporation in the second part 42, and then flows out of the second part 42. The refrigerant flowing to the first reversing assembly 2 flows into the first reversing assembly 2 through the first valve port 21, and flows out of the first reversing assembly 2 from the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3, and becomes high-temperature and high-pressure liquid refrigerant after heat exchange in the indoor heat exchanger 3, and then flows out of the indoor heat exchanger 3 to flow to the second throttle valve 44. The refrigerant throttled and reduced in pressure by the second throttle valve 44 flows into the second part 42, and evaporates into low-temperature and low-pressure superheated gaseous refrigerant in the second part 42, and then flows out of the second part 42. Finally, the refrigerant flowing out of the second part 42 flows back to the suction port 11 of the compressor 1 through the third valve port 23 and the fourth valve port 24 in turn.

[0121] S5: determining whether the second defrosting mode end condition is met;

[0122] S6: if the second defrosting mode end condition is met, controlling the second port 52 and the third port 53 of the second reversing assembly 5 to be open, the first throttle valve 43 to be throttled, and the second throttle valve 44 to be throttled, so as to exit the second defrosting mode and run the heating mode.

[0123] Therefore, when switching from the heating mode to the first defrosting mode and the second defrosting mode for defrosting the first portion 41 and the second portion 42, the first reversing component 2 is always not reversed, the power consumption of the air conditioning system 100 can be reduced, the air conditioning system 100 can realize uninterrupted heating, the indoor environment can always be kept at a high temperature, and the comfort of the user can be improved. Meanwhile, the second defrosting mode uses the high-temperature and high-pressure gaseous refrigerant discharged from the exhaust port 12 of the compressor 1 to defrost the first portion 41, and the defrosting effect is remarkable. The first defrosting mode uses the high-pressure and medium-temperature refrigerant flowing out of the indoor heat exchanger 3 to defrost the second portion 42, and the defrosting mode combines high-pressure latent defrosting and waste heat defrosting, which can not only take advantage of the waste heat defrosting and the high-pressure latent defrosting, but also avoid the problems of serious waste of waste heat defrosting capacity and high cost of high-pressure latent defrosting, and can improve the reliability and stability of the air conditioning system 100.

[0124] In addition, when the first portion 41 is located directly above the second portion 42, during the defrosting process of the outdoor heat exchanger component 4, the first portion 41 is defrosted first, and then the second portion 42 is defrosted after the defrosting of the first portion 41 is completed, which can ensure the defrosting effect of the outdoor heat exchanger component 4 and prevent the problem that when the second portion 42 is defrosted first and then the first portion 41 is defrosted, the defrosting water of the first portion 41 falls on the second portion 42 as an evaporator, which causes the second portion 42 to freeze and the defrosting effect of the second portion 42 to be poor.

[0125] In some embodiments, in order to improve the evaporation capacity of the second portion 42, the outdoor fan 46 is arranged on the side of the second portion 42 away from the first portion 41, and in step S4, if the air conditioning system 100 meets the first defrosting mode end condition, the outdoor fan 46 is turned on, so that air can be supplied to the second portion 42. In this way, after the defrosting of the second portion 42 is completed, the outdoor fan 46 is turned on to improve the evaporation capacity of the second portion 42, and then the suction pressure of the compressor 1 can be improved, so that the indoor side can quickly blow air after the defrosting of the air conditioning system 100 is completed, which is beneficial to improve the user experience.

[0126] In some embodiments, before determining whether the air conditioning system 100 meets the defrosting condition, the outdoor environment temperature Ta, the temperature Te1 of the second end of the first portion 41, and the temperature Te2 of the second end of the second portion 42 are obtained. If Ta≤a, Te1 / Te2≤b, and the continuous running time of the air conditioning system 100 in the heating mode reaches the first set time length, it is determined that the air conditioning system meets the defrosting condition. Therefore, the air conditioning system 100 can accurately determine whether to defrost, which is beneficial to improve the sensitivity and reliability of the defrosting of the air conditioning system 100.

[0127] For example, Figure 10In the embodiment, an outdoor temperature sensor 9 can be arranged outside the air conditioning system 100 to obtain an outdoor ambient temperature Ta, a first portion Te temperature sensor 411 can be arranged at the second end of the first portion 41 to obtain a temperature Te1 of the second end of the first portion 41, and a second portion Te temperature sensor 421 can be arranged at the second end of the second portion 42 to obtain a temperature Te2 of the second end of the second portion 42.

[0128] In some embodiments, -7℃ < a < 7℃. For example, the threshold value a of the outdoor ambient temperature Ta can be -6℃, -5℃, -4℃, -3℃, -2℃, -1℃, 0℃, 1℃, 2℃, 3℃, 4℃, 5℃ or 6℃, etc.

[0129] In some embodiments, -5℃ ≤ b ≤ 0℃. For example, the ratio of Te1 / Te2 can be -5℃, -4℃, -3℃, -2℃, -1℃ or 0℃, etc.

[0130] In some embodiments, the first set duration ≥ 10 min. For example, the first set duration can be 10 min, 11 min, 12 min, 13 min or 14 min, etc.

[0131] In some embodiments, the first defrosting mode end condition is that the temperature Te2 of the second end of the second portion 42 ≥ f and lasts for a first preset time. Thus, when the first defrosting mode end condition is met, the first defrosting mode can be exited in time, thereby facilitating to improve the intelligent degree and reliability of the air conditioning system 100.

[0132] In some embodiments, the second defrosting mode end condition is that the temperature Te1 of the second end of the first portion 41 ≥ f and lasts for a first preset time. Thus, when the second defrosting mode end condition is met, the second defrosting mode can be exited in time, thereby facilitating to improve the intelligent degree and reliability of the air conditioning system 100.

[0133] In some embodiments, 10℃ ≤ f ≤ 25℃. For example, the temperature f of the second end of the second portion 42 can be 10℃, 11℃, 12℃, 13℃, 14℃, 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃ or 25℃, etc.

[0134] In some embodiments, 5 seconds ≤ the first preset time ≤ 30 seconds. For example, the first preset time can be 5 seconds, 10 seconds, 15 seconds, 20 seconds, 25 seconds or 30 seconds, etc.

[0135] In some embodiments, the second throttle valve 44 is adjustable. When defrosting the first part 41, the opening of the second throttle valve 44 is adjusted to meet a first preset condition. The first preset condition is that the suction superheat of the compressor 1 meets Tssh≥d, and the discharge superheat of the compressor 1 meets Tdsh≥e; wherein Tssh=Tg2-Tc_ps, Tg2 is the temperature of the first end of the second part 42, and Tc_ps is the saturation temperature corresponding to the suction pressure Ps at the suction port 11. In this way, the accuracy of the opening control of the second throttle valve 44 can be improved, thereby facilitating the improvement of the reliability of the air conditioning system 100. It should be noted that Tdsh=Td-Tc_pd, Td is the temperature of the discharge port 12 of the compressor 1, and Tc_pd is the saturation temperature corresponding to the discharge pressure Pd at the discharge port 12.

[0136] For example, in the above-described embodiments, a second part temperature sensor 422 can be arranged at the first end of the second part 42 to obtain the temperature Tg2 of the first end of the second part 42. Figure 10 In the above-described embodiments, an air suction pressure sensor 111 can be arranged at the suction port 11 of the compressor 1 to detect the suction pressure Ps.

[0137] In some embodiments, the third throttle valve 61 is adjustable, and when defrosting the second part 42, the opening of the third throttle valve 61 is adjusted to meet a second preset condition. The second preset condition is that the suction superheat of the compressor 1 meets Tssh≥d, and the discharge superheat of the compressor 1 meets Tdsh≥e. Wherein Tssh=Tg1-Tc_ps, Tg1 is the temperature of the first end of the first part 41, and Tc_ps is the saturation temperature corresponding to the suction pressure Ps at the suction port 11.

[0138] For example, in the above-described embodiments, a first part temperature sensor 412 can be arranged at the first end of the first part 41 to obtain the temperature Tg1 of the first end of the first part 41. Figure 13 In some embodiments, 0℃≤d≤10℃. For example, the value of d can be 0℃, 1℃, 2℃, 3℃, 4℃, 5℃, 6℃, 7℃, 8℃, 9℃ or 10℃.

[0139] In some embodiments, 20℃≤e≤40℃. For example, the value of e can be 20℃, 25℃, 30℃, 35℃ or 40℃, etc.

[0140]

[0141] ​In some embodiments, when defrosting the second portion 42, the indoor fan of the air conditioning system 100 is controlled to stop running or run at the lowest wind speed. This configuration ensures that the refrigerant flowing into the second portion 42 has residual heat in the second defrost mode, thereby ensuring the defrosting efficiency of the second portion 42.

[0142] The above mainly introduces the solution provided by the embodiment of the present invention from the perspective of the air-conditioning system 100. It can be understood that in order to realize the above functions, the air-conditioning system 100 includes hardware structures and / or software modules corresponding to the execution of each function. It should be easily appreciated by those skilled in the art that, in combination with the algorithm steps of each example described in the embodiments disclosed herein, the present invention can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0143] In embodiments of the present invention, the air conditioning system 100 can be divided into functional modules based on the above-described method example. For example, each functional module can be divided into corresponding functional modules, or two or more functions can be integrated into a single processing module 103. These integrated modules can be implemented as either hardware or software functional modules. It should be noted that the module division in the embodiments of the present invention is illustrative and represents only one logical functional division. In actual implementation, other division methods may be used.

[0144] In the case of dividing each functional module into corresponding functional modules, Figure 13 Another possible schematic diagram of the air conditioning system involved in the above embodiment is shown. Figure 14 As shown, the air conditioning system 100 may include: a control unit 101 and a determination unit 102 .

[0145] The control unit 101 is used to support the air-conditioning system 100 in executing the steps of the control method of the air-conditioning system 100 shown in the figure.

[0146] The determining unit 102 is configured to support the air-conditioning system 100 in executing the steps of the control method of the air-conditioning system 100 .

[0147] It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module and will not be repeated here.

[0148] The air conditioning system 100 provided by the embodiment of the present application is used for executing the control method of the air conditioning system 100, and thus the same effect as the control method of the air conditioning system 100 can be achieved.

[0149] In the case of using the integrated unit, Figure 14 Another possible component diagram of the air conditioning system involved in the above embodiment is shown. As shown in the figure, Figure 15 The air conditioning system 100 includes a processing module 103, a communication module 104 and a storage module 105.

[0150] The processing module 103 is used for controlling and managing the actions of the air conditioning system 100. The communication module 104 is used for supporting the communication between the air conditioning system 100 and other network entities. The storage module 105 is used for storing the program codes and data of the air conditioning system 100.

[0151] The processing module 103 can be a processor 1031. It can realize or execute various exemplary logical blocks, modules and circuits described in combination with the disclosure of the present application. The processor 1031 can also be a combination of computing functions, such as a combination of one or more microprocessors 1031, a combination of a digital signal processor (DSP) and a microprocessor, etc. The communication module 104 can be a communication interface 1042. The storage module 105 can be a memory 1051.

[0152] When the processing module 103 is the processor 1031, the communication module 104 is the communication interface 1042, and the storage module 105 is the memory 1051, the air conditioning system 100 can be the device shown in the figure. Figure 15

[0153] Figure 15 The component diagram of the air conditioning system 100 provided by the embodiment of the present application is shown in the figure, Figure 15 The air conditioning system 100 can include at least one processor 1031 and a memory 1051.

[0154] The specific introduction of each component of the air conditioning system 100 is as follows: Figure 15

[0155] ​​The processor 1031 is the control center of the air conditioning system 100, and can be one processor 1031 or a plurality of processing elements. For example, the processor 1031 can be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to perform the functions of the embodiments of the present application, such as one or more DSPs, or one or more field programmable gate arrays (FPGAs).

[0156] In a specific implementation, as an embodiment, the processor 1031 can include one or more CPUs, such as the CPU0 and CPU1 shown in FIG. 10A. As an embodiment, the air conditioning system 100 can include a plurality of processors 1031, and each of the processors 1031 can be a single-CPU or a multi-CPU. The processor 1031 can refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions). Figure 15

[0157] The memory 1051 can be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disk storage, a magnetic disk storage or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to this. The memory 1051 can exist independently and be connected to the processor 1031 through the communication bus 1041. The memory 1051 can also be integrated with the processor 1031.

[0158] ​In a specific implementation, the memory 1051 is configured to store data used by the air conditioning system 100 and software programs that are executed by the air conditioning system 100. The processor 1031 can perform various functions of the air conditioning system 100 by running or executing the software programs stored in the memory 1051 and by calling data stored in the memory 1051.

[0159] The air conditioning system 100 can further include a communication interface 1042 and a communication bus 1041.

[0160] The communication interface 1042 is configured to communicate with other devices or communication networks, such as a Radio Access Network (RAN), a Wireless Local Area Networks (WLAN), etc., using any transceiver-like mechanism. The communication interface 1042 can include a receiver for receiving information and a transmitter for transmitting information.

[0161] The communication bus 1041 can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, ​ In the description of the present specification, only one thick line is used to represent the bus, but it does not mean that there is only one bus or only one type of bus.

[0162] In the description of the present specification, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0163] The above description is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An air conditioning system, characterized by, The air conditioning system comprises: a compressor having a suction port and a discharge port; a first reversing assembly having first to fourth valve ports, the first valve port being connected to the discharge port, the fourth valve port being connected to the suction port, the first valve port being reversibly connected to one of the second valve port and the third valve port, the fourth valve port being reversibly connected to the other of the second valve port and the third valve port; a second reversing assembly having first to third ports, the first port being connected to the discharge port, the second port being connected to the suction port, the third port being reversibly connected to one of the first port and the second port; an indoor heat exchanger, a first end of the indoor heat exchanger being connected to the second valve port; an outdoor heat exchanger assembly comprising a first part and a second part, a first end of the first part being connected to the third port, a first on-off valve being connected in series between a first end of the second part and the third valve port, a first throttling valve being connected between a second end of the first part and a second end of the indoor heat exchanger, a second throttling valve being connected between a second end of the second part and the second end of the indoor heat exchanger; a bypass branch, a first end of the bypass branch being connected to the first end of the second part, a second end of the bypass branch being connected to a pipeline between the first throttling valve and the second end of the first part, a third throttling valve being connected in series in the bypass branch.

2. The air conditioning system of claim 1, wherein, The first part is located directly above the second part, or the first part is located directly below the second part.

3. The air conditioning system of claim 1, wherein, The second reversing assembly is a three-way reversing valve or a four-way reversing valve. When the second reversing assembly is a four-way reversing valve, the second reversing assembly further comprises a fourth port, the fourth port being blocked, and the fourth port being reversibly connected to the other of the first port and the second port.

4. The air conditioning system of claim 1, wherein, The first part and the second part are two independent heat exchangers, or the first part and the second part are two parts of the same heat exchanger.

5. A defrosting control method of an air conditioning system, characterized by, The defrosting control method is applied to the air conditioning system according to any one of claims 1-4, and the defrosting control method comprises the following steps: When the air conditioning system operates in a heating mode, it is determined whether the air conditioning system meets a defrosting condition; If yes, the air conditioning system is controlled to operate in a first defrosting mode, in which one of the first part and the second part is defrosted; It is determined whether the air conditioning system meets a first defrosting mode end condition; If yes, the air conditioning system is controlled to exit the first defrosting mode and operate in a second defrosting mode, in which the other of the first part and the second part is defrosted; It is determined whether the air conditioning system meets a second defrosting mode end condition; If yes, the air conditioning system is controlled to exit the second defrosting mode and operate in the heating mode; When the first part is defrosted, the third port is reversibly connected to the first port; The first throttling valve is fully opened, the second throttling valve is throttled, the first on-off valve is opened, and the third throttling valve is fully closed. In defrosting the second part, the third port is controlled to be communicated with the second port, the first throttle valve is fully closed, the second throttle valve is fully opened, the first on-off valve is closed, and the third throttle valve is throttled.

6. The defrosting control method of an air conditioning system according to claim 5, wherein Before determining that the air conditioning system meets the defrosting condition, an outdoor environment temperature Ta, a temperature Te1 of a second end of the first part, and a temperature Te2 of a second end of the second part are obtained. If Ta≤a, Te1 / Te2≤b, and a continuous running time of the air conditioning system in the heating mode reaches a first set time length, it is determined that the air conditioning system meets the defrosting condition, where a is a preset threshold value of the outdoor environment temperature Ta, and b is a preset threshold value of a ratio of the temperature Te1 of the second end of the first part to the temperature Te2 of the second end of the second part.

7. The defrosting control method of an air conditioning system according to claim 5, wherein In the first defrosting mode, the first part is defrosted, and in the second defrosting mode, the second part is defrosted. The first defrosting mode end condition is that the temperature Te1 of the second end of the first part is greater than or equal to f and lasts for a first preset time, where f is a preset threshold value of the temperature Te1 of the second end of the first part, and / or the second defrosting mode end condition is that the temperature Te2 of the second end of the second part is greater than or equal to f and lasts for a first preset time, where f is a preset threshold value of the temperature Te2 of the second end of the second part.

8. The defrosting control method of an air conditioning system according to claim 5, wherein, In the first defrosting mode, the second part is defrosted, and in the second defrosting mode, the first part is defrosted. The first defrosting mode end condition is that the temperature Te2 of the second end of the second part is greater than or equal to f and lasts for a first preset time, where f is a preset threshold value of the temperature Te2 of the second end of the second part, and / or the second defrosting mode end condition is that the temperature Te1 of the second end of the first part is greater than or equal to f and lasts for a first preset time, where f is a preset threshold value of the temperature Te1 of the second end of the first part.

9. The defrosting control method of an air conditioning system according to claim 5, wherein, The second throttle valve flow degree is adjustable, and in defrosting the first part, the flow degree of the second throttle valve is adjusted to meet a first preset condition. The first preset condition is that suction superheat of the compressor meets Tssh≥d, and discharge superheat of the compressor meets Tdsh≥e; d is a preset threshold value of the suction superheat of the compressor, and e is a preset threshold value of the discharge superheat of the compressor. Tssh=Tg2-Tc_ps, Tg2 is a temperature of a first end of the second part, and Tc_ps is a saturation temperature corresponding to suction pressure Ps at the suction port.

10. The defrosting control method of an air conditioning system according to claim 5, wherein, The third throttle valve flow degree is adjustable, and in defrosting the second part, the flow degree of the third throttle valve is adjusted to meet a second preset condition. The second preset condition is that suction superheat of the compressor meets Tssh≥d, and discharge superheat of the compressor meets Tdsh≥e; d is a preset threshold value of the suction superheat of the compressor, and e is a preset threshold value of the discharge superheat of the compressor. Wherein, Tssh=Tg1-Tc_ps, Tg1 is the temperature of the first end of the first portion, and Tc_ps is the saturation temperature corresponding to the suction pressure Ps at the suction port.

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