An air conditioning system

Abstract

The application discloses an air conditioning system, and relates to the technical field of air conditioners, which can improve the comfort of users to some extent. The indoor unit is provided with an indoor heat exchanger; the outdoor unit comprises an outdoor heat exchanger, the outdoor heat exchanger comprises a first part and a second part; the indoor heat exchanger is connected with the outdoor heat exchanger through gas side pipes and liquid side pipes; the first part is defrosted by using refrigerant sensible heat, and the second part is defrosted by using refrigerant waste heat; wherein, the refrigerant sensible heat defrosting and the refrigerant waste heat defrosting are not simultaneously performed, the outdoor heat exchanger is divided into the first part and the second part by being divided into upper and lower parts, and the upper and lower heat exchangers can be alternately defrosted. The four-way valve is not reversed during the whole defrosting process, and the comfort of users is ensured.

Description

Technical Field

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

[0002] When an air conditioning system is operating in heating mode, the outdoor heat exchanger assembly will frost over when the ambient temperature and humidity reach certain levels. In related technologies, air conditioning systems use reverse defrosting to defrost the outdoor heat exchanger assembly. This involves reversing the flow of refrigerant used for heating, supplying the outdoor heat exchanger assembly with refrigerant discharged from the compressor, and using the compressor's heat to defrost it. During reverse defrosting, the air conditioning system stops heating the indoor space, and the indoor heat exchanger also needs to absorb some heat from the room, lowering the indoor temperature and severely impacting indoor thermal comfort, thus reducing the user experience. Summary of the Invention

[0003] Embodiments of the present invention provide an air conditioning system that can at least improve user comfort to a certain extent.

[0004] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions: The indoor unit provided in this application embodiment has an indoor heat exchanger; the outdoor unit includes an outdoor heat exchanger, which includes a first part and a second part; the indoor heat exchanger and the outdoor heat exchanger are connected via gas-side piping and liquid-side piping; the first part uses sensible heat of the refrigerant for defrosting, and the second part uses waste heat of the refrigerant for defrosting; wherein, the sensible heat defrosting and the waste heat defrosting are not performed simultaneously.

[0005] 1) This invention proposes a defrosting solution that enables uninterrupted heating. By dividing the outdoor unit's heat exchanger into upper and lower sections, specifically a first and a second section, defrosting can be performed alternately on both sections. The four-way valve remains stationary throughout the defrosting process, ensuring user comfort. 2) The first section of the heat exchanger uses hot gas bypass defrosting, allowing the indoor unit to maintain a high-pressure, high-temperature state. The second section uses waste heat defrosting. During defrosting of the second section, the indoor unit remains dry or experiences only a slight breeze. Incomplete heat exchange occurs, with some heat remaining in the second section for defrosting, resulting in fast defrosting speed and high reliability. After defrosting, the indoor unit can be quickly started to produce airflow, demonstrating excellent performance. 3) The upper and lower heat exchangers are divided into sections. Defrosting of the first and second heat exchangers utilizes hot gas bypass (low-pressure sensible heat) and high-pressure waste heat defrosting respectively. This combined high- and low-pressure defrosting method leverages the advantages of both waste heat and hot gas bypass defrosting while effectively avoiding the drawbacks of significant waste of waste heat defrosting capacity, poor reliability of hot gas bypass defrosting, and narrow applicability. 4) After defrosting the first heat exchanger using hot gas bypass, the outdoor unit fan can operate while defrosting the second heat exchanger using the waste heat from the indoor unit's refrigerant. This improves the evaporation capacity of the first heat exchanger. Simultaneously, the indoor unit can also ventilate, ensuring user comfort and potentially guaranteeing compressor reliability. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the composition of an air conditioning system provided in the first embodiment of this application; Figure 2 This is a schematic diagram of the composition of an air conditioning system provided in the second embodiment of this application; Figure 3 A schematic diagram of the cooling mode of the air conditioning system provided in the first embodiment of this application; Figure 4 A schematic diagram illustrating the cooling mode of an air conditioning system provided in the second embodiment of this application; Figure 5 A schematic diagram illustrating the heating mode of the air conditioning system provided in the first embodiment of this application; Figure 6 A schematic diagram illustrating the heating mode of an air conditioning system provided in the second embodiment of this application; Figure 7 A schematic diagram of the air conditioning system defrosting the first part according to the first embodiment of this application; Figure 8 This is a schematic diagram of the air conditioning system defrosting the first part according to the second embodiment of this application; Figure 9 A schematic diagram illustrating the defrosting of the second part by the air conditioning system provided in the first embodiment of this application; Figure 10A schematic diagram illustrating the defrosting of the second part by an air conditioning system provided in the second embodiment of this application; Figure 11 A flowchart of a first defrosting control method for an air conditioning system provided in an embodiment of this application; Figure 12 A flowchart of a second defrosting control method for an air conditioning system provided in an embodiment of this application. Detailed Implementation

[0007] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0008] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0009] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0010] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0011] When an air conditioning system is operating in heating mode, the outdoor heat exchanger assembly will frost over when the ambient temperature and humidity reach certain levels. In related technologies, air conditioning systems use reverse defrosting to defrost the outdoor heat exchanger assembly. This involves reversing the flow of refrigerant used for heating, supplying the outdoor heat exchanger assembly with refrigerant discharged from the compressor, and using the compressor's heat to defrost it. During reverse defrosting, the air conditioning system stops heating the indoor space, and the indoor heat exchanger also needs to absorb some heat from the room, lowering the indoor temperature and severely impacting indoor thermal comfort, thus reducing the user experience.

[0012] To address the aforementioned technical problems, this application improves the system by ensuring that the indoor heat exchanger remains in its condenser function during defrosting of the outdoor heat exchanger assembly. Specifically, by including a first part and a second part connected in parallel in the outdoor heat exchanger assembly, when the air conditioning system defrosts the first part, a portion of the refrigerant bypassing the compressor's exhaust port is used to defrost it. Meanwhile, the second part can continue to function as an evaporator to maintain the heating cycle of the air conditioning system. Conversely, when the air conditioning system defrosts the second part, the latent heat of the high-pressure, medium-temperature refrigerant flowing from the indoor heat exchanger is used to defrost it. At this time, the first part can continue to function as an evaporator to maintain the heating cycle of the air conditioning system. This allows for alternating defrosting of the first and second parts while maintaining the indoor heat exchanger's heating function, preventing any impact on the indoor temperature during defrosting and maintaining a high indoor temperature, thus improving user comfort. Furthermore, using the high-temperature, high-pressure gaseous refrigerant discharged from the compressor's exhaust port to defrost the first part results in a significant defrosting effect. The second section is defrosted using the high-pressure, medium-temperature refrigerant flowing from the indoor heat exchanger, resulting in a significant defrosting effect. This defrosting method, combining low-pressure sensible heat with high-pressure waste heat, not only leverages the advantages of both sensible and waste heat defrosting but also avoids the significant waste of waste heat defrosting capacity and the poor reliability and narrow applicability of sensible heat defrosting. Consequently, it can improve the defrosting speed and reliability of the air conditioning system to a certain extent.

[0013] The air conditioning system of the present application embodiment will be described below.

[0014] Please see Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the composition of an air conditioning system provided in the first embodiment of this application. Figure 2 This is a schematic diagram of the composition of an air conditioning system provided in a second embodiment of this application. This application provides an air conditioning system 100, including: a compressor 1, a commutation assembly 2, an indoor heat exchanger 3, an outdoor heat exchanger assembly 4, a defrost branch 5, and a bypass branch 6.

[0015] Specifically, the indoor unit has an indoor heat exchanger 3, and the outdoor unit includes an outdoor heat exchanger assembly 4. The outdoor heat exchanger assembly includes a first part 41 and a second part 42. The indoor heat exchanger and the outdoor heat exchanger are connected by gas-side piping and liquid-side piping. The first part 41 uses the sensible heat of the refrigerant for defrosting, and the second part 42 uses the waste heat of the refrigerant for defrosting. The sensible heat defrosting and the waste heat defrosting are not performed simultaneously.

[0016] It should be noted that during refrigerant sensible heat defrosting, the refrigerant is discharged directly into the first section 41 after being discharged from the compressor 1, and defrosting is performed by utilizing the sensible heat of the high-temperature and high-pressure gaseous refrigerant; refrigerant waste heat defrosting utilizes the refrigerant flowing through the indoor heat exchanger, and by stopping the fan or running the fan at a low speed, the refrigerant does not exchange heat sufficiently, so that the refrigerant with insufficient heat exchange flows through the second section to defrost the second section.

[0017] Specifically, to switch between the two defrosting methods, when the first part uses the sensible heat of the refrigerant for defrosting, the first and second parts are connected in parallel. When the second part uses the waste heat of the refrigerant for defrosting, the first and second parts are connected in series.

[0018] Specifically, to achieve the heating effect without cooling during defrosting, the system also includes an outdoor fan, which is installed on one side of the outdoor heat exchanger; when the first part uses the sensible heat of the refrigerant for defrosting, the outdoor fan operates to improve the evaporation capacity of the first part.

[0019] It also includes: an indoor fan, located on one side of the indoor heat exchanger; when the second part uses refrigerant waste heat for defrosting, the indoor fan stops, and the refrigerant waste heat defrosting is sensible heat and latent heat defrosting; or the indoor fan operates at a speed not lower than the upper limit speed, and the refrigerant waste heat defrosting is sensible heat defrosting.

[0020] The indoor fan can operate at a speed not lower than the upper limit, meaning it can run at a low speed. By controlling the fan, the subcooling of the liquid refrigerant after passing through the indoor unit can be controlled. When the fan is running at a low speed, the refrigerant is in a subcooled liquid state, and defrosting using residual refrigerant heat is sensible heat defrosting. In another embodiment, when the second part uses refrigerant waste heat for defrosting, the indoor unit stops. Refrigerant waste heat defrosting can also be sensible heat defrosting, or when the indoor fan is running at a speed not lower than the upper limit, refrigerant waste heat defrosting can be sensible heat and latent heat defrosting.

[0021] Please continue reading. Figure 1 The compressor 1 has an intake port 11 and an exhaust port 12. Specifically, the intake port 11 of the compressor 1 is used to draw in air. The refrigerant enters the compression chamber of the compressor 1 through the intake port 11 and is compressed to form a high-temperature and high-pressure refrigerant. The high-temperature and high-pressure refrigerant gas is then discharged from the compressor 1 through the exhaust port 12 and then enters the air conditioning system 100 for refrigerant circulation.

[0022] For example, compressor 1 can be a scroll compressor, rotary compressor, screw compressor or other types of compressor.

[0023] Please continue reading. Figure 1The 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 to the exhaust port 12. The fourth valve port 24 is connected to the intake port 11. The first valve port 21 can be switched to be connected to one of the second valve port 22 and the third valve port 23, and the fourth valve port 24 can be switched to be connected to the other of the second valve port 22 and the third valve port 23. That is, when the first valve port 21 is connected to the second valve port 22, the third valve port 23 is connected to the fourth valve port 24; when the first valve port 21 is connected to the third valve port 23, the second valve port 22 is connected to the fourth valve port 24.

[0024] For example, the reversing assembly 2 can be a four-way directional valve. The four-way directional valve can have two states: open and closed. When the four-way directional valve is energized, it is open, with the first valve port 21 connected to the second valve port 22, and the third valve port 23 connected to the fourth valve port 24. When the four-way directional valve is de-energized, it is closed, with the first valve port 21 connected to the third valve port 23, and the second valve port 22 connected to the fourth valve port 24. Of course, it is understood that in other examples, when the four-way directional valve is de-energized, the first valve port 21 is connected to the second valve port 22, and the third valve port 23 is connected to the fourth valve port 24; when the four-way directional valve is energized, the first valve port 21 is connected to the third valve port 23, and the second valve port 22 is connected to the fourth valve port 24.

[0025] Please continue reading. Figure 1 The first end of the indoor heat exchanger 3 is connected to the second valve port 22.

[0026] Please continue reading. Figure 1 The outdoor heat exchanger assembly 4 includes a first part 41 and a second part 42. A first end of the first part 41 is connected to a third valve port 23. A first end of the second part 42 is also connected to the third valve port 23, and a first on / off valve 45 is connected in series between the two. The first on / off valve 45 can be used to control the on / off connection between the first end of the second part 42 and the third valve port 23.

[0027] Therefore, the first end of the first part 41 can be connected to the third valve port 23, and the connection between the second part 42 and the third valve port 23 can be controlled by the first on / off valve 45, which helps to improve the reliability of the air conditioning system 100.

[0028] Please continue reading. Figure 1A first throttling valve 43 is connected between the second end of the first part 41 and the second end of the indoor heat exchanger 3. The first throttling valve 43 can throttle and reduce the pressure of the refrigerant flowing through it. The first throttling valve 43 can also control the connection between the second end of the first part 41 and the second end of the indoor heat exchanger 3. That is, the opening degree of the first throttling valve 43 is adjustable. The first throttling valve 43 can have a fully open state (100% opening), a fully closed state (0% opening), and a throttling state (opening degree between 0 and 100%). In the fully closed state, there is no electrical connection between the second end of the first part 41 and the second end of the indoor heat exchanger 3. In the fully open and throttling states, there is electrical connection between the second end of the first part 41 and the second end of the indoor heat exchanger 3, and in the throttling state, the first throttling valve 43 can throttle and reduce the pressure of the refrigerant flowing through it.

[0029] A second throttling valve 44 is connected between the second end of the second part 42 and the second end of the indoor heat exchanger 3. The second throttling valve 44 can throttle and reduce the pressure of the refrigerant flowing through it. The second throttling valve 44 can also control the connection between the second end of the second part 42 and the second end of the indoor heat exchanger 3. That is, the opening degree of the second throttling valve 44 is adjustable. The second throttling valve 44 can have a fully open state (100% opening), a fully closed state (0% opening), and a throttling state (opening degree between 0 and 100%). In the fully closed state, there is no electrical connection between the second end of the second part 42 and the second end of the indoor heat exchanger 3. In the fully open state and the throttling state of the first part 41, there is electrical connection between the second end of the second part 42 and the second end of the indoor heat exchanger 3, and in the throttling state, the second throttling valve 44 can throttle and reduce the pressure of the refrigerant flowing through it.

[0030] Therefore, the connection between the second end of the first part 41 and the second end of the indoor heat exchanger 3 can be controlled by opening and closing the first throttle valve 43, and the refrigerant flowing through the first throttle valve 43 can be throttled and its pressure reduced by controlling the opening degree of the first throttle valve 43. Similarly, the connection between the second end of the second part 42 and the second end of the indoor heat exchanger 3 can be controlled by opening and closing the second throttle valve 44, and the refrigerant flowing through the first throttle valve 43 can be throttled and its pressure reduced by controlling the opening degree of the first throttle valve 43. This improves the stability and reliability of the air conditioning system 100.

[0031] Please continue reading. Figure 1The first end of the defrost branch 5 is connected to the exhaust port 12. The second end of the defrost branch 5 is connected to the pipeline between the first throttle valve 43 and the second end of the first section 41. A second on-off valve 51 is connected in series on the defrost branch 5. The second on-off valve 51 can control the on / off state of the defrost branch 5. It can be understood that the second end of the defrost branch 5 is located between the first throttle valve 43 and the second end of the first section 41. The refrigerant in the defrost branch 5 can bypass the first throttle valve 43 and directly enter the first section 41, which can prevent the first throttle valve 43 from affecting the state of the refrigerant in the defrost branch 5, thereby ensuring that the refrigerant in the defrost branch 5 is in a high temperature and high pressure state. In addition, when there is frost on the first section 41, the high temperature and high pressure gaseous refrigerant discharged from the exhaust port 12 can be opened by controlling the second on-off valve 51, so that the high temperature and high pressure gaseous refrigerant discharged from the exhaust port 12 can enter the first section 41 along the defrost branch 5, thereby using the sensible heat of the compressor 1 exhaust to defrost the first section 41. Meanwhile, when defrosting of the first part 41 is not required, the second on / off valve 51 can be closed to prevent the high-temperature and high-pressure gaseous refrigerant discharged from the exhaust port 12 from flowing to the defrost branch 5, thereby affecting the normal operation of the air conditioning system 100 and improving the reliability of the air conditioning system 100.

[0032] Please continue reading. Figure 1 The first end of bypass branch 6 is connected to the first end of the second part 42. The second end of bypass branch 6 is connected to the pipeline between the first throttle valve 43 and the second end of the first part 41. A third throttle valve 61 is connected in series on bypass branch 6. The third throttle valve 61 can throttle and reduce the pressure of the refrigerant flowing through it. The third throttle valve 61 can also control the connection between the first end of the second part 42 and the second end of the first part 41. That is, the opening degree of the third throttle valve 61 is adjustable. The third throttle valve 61 can have a fully open state (100% opening degree), a fully closed state (0% opening degree), and a throttling state (opening degree between 0 and 100%). In the fully closed state of the third throttle valve 61, there is no connection between the first end of the second part 42 and the second end of the first part 41. In the fully open and throttling states of the first part 41, the first end of the second part 42 is connected to the second end of the first part 41, and in the throttling state, the third throttling valve 61 can throttle and reduce the pressure of the refrigerant flowing through it.

[0033] The air conditioning system 100 according to an embodiment of this application has a cooling mode, a heating mode, and a defrost mode. The control process and refrigerant flow direction of the cooling mode, heating mode, and defrost mode according to an embodiment of this application will be described in detail below.

[0034] Cooling mode Please see Figure 3 and Figure 4 , Figure 3This is a schematic diagram of the cooling mode of the air conditioning system provided in the first embodiment of this application. Figure 4 This is a schematic diagram of the air conditioning system in cooling mode according to the second embodiment of this application. When the air conditioning system 100 is in cooling mode, the first valve port 21 and the third valve port 23 of the reversing assembly 2 are connected, the second valve port 22 and the fourth valve port 24 are connected, the first on-off valve 45 is open, the second on-off valve 51 is open, the first throttle valve 43 throttles, the second throttle valve 44 throttles, and the third throttle valve 61 is fully closed.

[0035] Refrigerant Flow: The high-temperature, high-pressure gaseous refrigerant discharged from the exhaust port 12 of the compressor 1 flows into the reversing assembly 2 through the first valve port 21 and exits the reversing assembly 2 through the third valve port 23. The refrigerant exiting from the third valve port 23 flows to the first section 41 and the second section 42 respectively, and becomes a high-pressure subcooled liquid refrigerant after sufficient heat exchange in the first section 41 and the second section 42. Then, the refrigerant exiting from the first section 41 flows through the first throttling valve 43 for throttling and pressure reduction, and the refrigerant exiting from the second section 42 flows through the second throttling valve 44 for throttling and pressure reduction. The refrigerant after throttling and pressure reduction by the first throttling valve 43 and the refrigerant after throttling and pressure reduction by the second throttling valve 44 flows into the indoor heat exchanger 3, and becomes a low-temperature, low-pressure superheated gaseous refrigerant after heat exchange in the indoor heat exchanger 3. Finally, it flows back to the suction port 11 of the compressor 1 through the second valve port 22 and the fourth valve port 24 in sequence, thus completing the refrigeration cycle of the air conditioning system 100.

[0036] Heating mode Please see Figure 5 and Figure 6 , Figure 5 This is a schematic diagram of the heating mode of the air conditioning system provided in the first embodiment of this application. Figure 6 This is a schematic diagram of the heating mode of the air conditioning system provided in the second embodiment of this application. When the air conditioning system 100 is in the heating mode, the first valve port 21 and the second valve port 22 of the control reversing assembly 2 are connected, the third valve port 23 and the fourth valve port 24 are connected, the first on-off valve 45 is open, the second on-off valve 51 is open, the first throttling valve 43 throttles, the second throttling valve 44 throttles, and the third throttling valve 61 is fully closed.

[0037] Refrigerant Flow: The high-temperature, high-pressure gaseous refrigerant discharged from the exhaust port 12 of the compressor 1 flows into the reversing assembly 2 through the first valve port 21 and exits the reversing assembly 2 through the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3, where it undergoes heat exchange and becomes a high-temperature, high-pressure liquid refrigerant. It then flows out of the indoor heat exchanger 3 and flows to the first throttling valve 43 and the second throttling valve 44. After being throttled and depressurized by the first throttling valve 43, the refrigerant flows into the first section 41 and evaporates into a low-temperature, low-pressure superheated gaseous refrigerant. After being throttled and depressurized by the second throttling valve 44, the refrigerant flows into the second section 42 and evaporates into a low-temperature, low-pressure superheated gaseous refrigerant. Finally, the refrigerant flowing out of the first section 41 and the second section 42 flows back to the suction port 11 of the compressor 1 through the third valve port 23 and the fourth valve port 24, thus completing the heating cycle of the air conditioning system 100.

[0038] Defrosting mode Please see Figure 7 and Figure 8 , Figure 7 This is a schematic diagram illustrating the defrosting of a first part in the air conditioning system provided in the first embodiment of this application. Figure 8 This is a schematic diagram of the air conditioning system provided in the second embodiment of this application defrosting the first part. When defrosting the first part 41, the first valve port 21 and the second valve port 22 of the control reversing assembly 2 are connected, the third valve port 23 and the fourth valve port 24 are connected, the first throttle valve 43 is fully closed, the second throttle valve 44 is throttled, the first on-off valve 45 is opened, the second on-off valve 51 is opened, and the third throttle valve 61 is fully closed.

[0039] Refrigerant Flow: The high-temperature, high-pressure gaseous refrigerant discharged from the exhaust port 12 of the compressor 1 flows into the reversing assembly 2 through the first valve port 21 and exits the reversing assembly 2 through the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3 and the defrost branch 5 respectively. The high-temperature, high-pressure gaseous refrigerant flowing to the indoor heat exchanger 3 is condensed into a high-temperature, high-pressure subcooled liquid refrigerant after sufficient heat exchange in the indoor heat exchanger 3. Then, it flows out of the indoor heat exchanger 3 and flows to the second throttling valve 44. After being throttled by the second throttling valve 44, it becomes a low-temperature, low-pressure two-phase refrigerant. Then, it flows to the second section 42, where it becomes a low-temperature, low-pressure superheated gaseous refrigerant through evaporation. The high-temperature, high-pressure gaseous refrigerant flowing to the defrost branch 5 flows into the first section 41, where the sensible heat of the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 1 is used to remove the frost from the first section 41. The refrigerant flowing out from the first part 41 and the refrigerant flowing out from the second part 42 flow back to the suction port 11 of the compressor 1 through the third valve port 23 and the fourth valve port 24 in sequence, thus completing the defrosting refrigerant circulation of the first part 41.

[0040] Please see Figure 9 and Figure 10 , Figure 9 This is a schematic diagram illustrating the defrosting of the second part by the air conditioning system provided in the first embodiment of this application. Figure 10 This is a schematic diagram of the air conditioning system provided in the second embodiment of this application defrosting the second part. When defrosting the second part 42, the first valve port 21 and the second valve port 22 of the control reversing assembly 2 are connected, the third valve port 23 and the fourth valve port 24 are connected, the first throttle valve 43 is fully closed, the second throttle valve 44 is fully open, the first on-off valve 45 is fully closed, the second on-off valve 51 is closed, and the third throttle valve 61 is throttled.

[0041] Refrigerant Flow: The high-temperature, high-pressure gaseous refrigerant discharged from the exhaust port 12 of the compressor 1 flows into the reversing assembly 2 through the first valve port 21 and exits the reversing assembly 2 through 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, high-pressure gaseous refrigerant undergoes incomplete heat exchange in the indoor heat exchanger 3, and after heat exchange, it becomes a high-temperature, high-pressure subcooled liquid refrigerant with a small degree of subcooling or a two-phase refrigerant. After flowing out of the indoor heat exchanger 3, it flows to the second throttling valve 44, and after passing through the second throttling valve 44, it flows to the second section 42. Then, it utilizes the waste heat of the high-temperature, high-pressure subcooled liquid refrigerant with a small degree of subcooling (waste heat is sensible heat) or the high-temperature, high-pressure two-phase refrigerant (waste heat is sensible heat plus latent heat) flowing out of the indoor heat exchanger 3. The second part 42 is defrosted. The refrigerant after defrosting in the second part 42 flows to the bypass branch 6, and then to the third throttling valve 61 on the bypass branch 6. After being throttled and depressurized by the third throttling valve 61, it becomes a low-temperature and low-pressure two-phase refrigerant. Then it flows back into the first part 41 and evaporates into a 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 third valve port 23 and the fourth valve port 24 in sequence, thus completing the defrosting refrigerant cycle of the second part 42.

[0042] Therefore, a portion of the refrigerant bypassing the compressor 1's exhaust port 12 via the defrost branch 5 can be used to defrost the first section 41, while the high-pressure, medium-temperature refrigerant flowing from the indoor heat exchanger 3 can be used to defrost the second section 42. This allows for alternating defrosting of the first and second sections 41 while maintaining the heating function of the indoor heat exchanger 3. Furthermore, the commutation component 2 does not reverse direction during the switching between heating and defrosting, thus extending its service life.

[0043] Please continue reading. Figure 9 The first part 41 can be located directly above the second part 42. For example... Figure 10 As shown, the first part 41 can also be located directly below the second part 42. Therefore, the defrosting branch 5 and the bypass branch 6 can be rationally configured, which helps reduce costs.

[0044] Please continue reading. Figure 9 The second end of the bypass branch 6 is connected to the pipe between the second end of the defrost branch 5 and the second end of the first part 41. This arrangement can, on the one hand, prevent the defrost branch 5 from affecting the bypass branch 6, which is beneficial to improving the reliability of the air conditioning system 100, and on the other hand, allow for a reasonable setting of the location of the bypass branch 6.

[0045] In other embodiments, please refer to Figure 10 The second end of the bypass branch 6 is connected to the pipeline between the second end of the defrost branch 5 and the first throttle valve 43. Therefore, the position of the bypass branch 6 can be appropriately configured.

[0046] Please see Figure 9 The first throttle valve 43, the second throttle valve 44, and the third throttle valve 61 can be electronic expansion valves. This configuration can improve the operating speed and accuracy of the air conditioning system 100. In other embodiments, the first throttle valve 43, the second throttle valve 44, and the third throttle valve 61 can also be thermostatic expansion valves.

[0047] In some embodiments, the first part 41 and the second part 42 can be divided into two independent heat exchangers. Therefore, when the air conditioning system 100 is in cooling or heating mode, the situation where the air conditioning system 100 stops working due to damage to either the first part 41 or the second part 42 can be avoided, thus improving the stability and reliability of the air conditioning system 100 operation.

[0048] In other embodiments, the first part 41 and the second part 42 may also be divided into two parts of the same heat exchanger. This arrangement facilitates the assembly of the air conditioning system 100, thereby improving the assembly efficiency of the air conditioning system 100.

[0049] In some embodiments, the first on / off valve 45 can be a two-way valve. This configuration helps to improve the response speed and reliability of the air conditioning system 100.

[0050] In some embodiments, the second on / off valve 51 can be a solenoid valve. This configuration helps to improve the response speed and reliability of the air conditioning system 100.

[0051] In other embodiments, the second on / off valve 51 may also be an electronic expansion valve.

[0052] Please continue reading. Figure 9The first throttling valve 43 and the second throttling valve 44 are connected to the second end of the indoor heat exchanger 3 through the same subcooler 47. By setting the subcooler 47, the flash gas generated by the air conditioning system 100 during the throttling process can be reduced, which is beneficial to improving the cooling capacity of the air conditioning system 100 and also can improve the stability of the compressor 1, thereby improving the stability and reliability of the air conditioning system 100.

[0053] Please continue reading. Figure 1 The first end of the indoor heat exchanger 3 is connected to a first shut-off valve 31, and the second end of the indoor heat exchanger 3 is connected to a second shut-off valve 32. Therefore, by setting the first shut-off valve 31 and the second shut-off valve 32, it is convenient to maintain and repair the air conditioning system 100. Specifically, when the indoor heat exchanger 3 needs repair or replacement, the first shut-off valve 31 and the second shut-off valve 32 can be closed, thus allowing for more convenient maintenance of the indoor heat exchanger 3 without having to discharge the refrigerant from the entire air conditioning system 100.

[0054] For example, the air conditioning system 100 can be a multi-split system. The air conditioning system 100 includes multiple indoor units. Each indoor unit is equipped with an indoor heat exchanger 3. The multiple indoor units are connected in parallel. The first end of the indoor heat exchanger 3 of each of the multiple indoor units can be connected to a first shut-off valve 31. The second end of the indoor heat exchanger 3 of each of the multiple indoor units can be connected to a second shut-off valve 32. Of course, it is understood that in other examples, the air conditioning system 100 may also include only a single indoor unit.

[0055] Please continue reading. Figure 1 In some embodiments, the air conditioning system 100 further includes a gas-liquid separator 7. The gas-liquid separator 7 is disposed between the compressor 1 and the 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 a fourth valve port 24. The gas outlet 72 is connected to the suction port 11. By providing a gas-liquid separator, the refrigerant entering the compressor 1 can be separated into gas and liquid components, avoiding liquid slugging problems and thus protecting the compressor 1.

[0056] Please continue reading. Figure 1 In some embodiments, the air conditioning system 100 further includes an oil-gas separator 8. The oil-gas separator 8 is disposed between the compressor 1 and the reversing assembly 2. The oil-gas separator 8 has an inlet 81, a gas outlet 82, and an oil outlet 84. The inlet 81 is connected to the exhaust port 12. The gas outlet 82 is connected to the first valve port 21. The oil outlet 84 is connected to the suction port 11. By providing the oil-gas separator 8, the protection of the compressor 1 can be improved, thereby contributing to the improvement of the stability and reliability of the air conditioning system 100.

[0057] Please continue reading. Figure 1In some embodiments, the air conditioning system 100 further includes 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 separator 8. The oil return capillary tube 83 can return the liquid separated in the oil separator 8 to the suction port 11 of the compressor 1.

[0058] Please continue reading. Figure 1 In some embodiments, an outdoor fan 46 may be provided on one side of the outdoor heat exchanger assembly. This arrangement can improve the heat exchange efficiency of the outdoor heat exchanger assembly 4.

[0059] Based on the structure of the air conditioning system 100 described above, there are two defrosting methods for the air conditioning system 100 in this application embodiment. The defrosting control method of the air conditioning system 100 in the first embodiment of this application will be described below.

[0060] Please see Figure 11 , Figure 11 A flowchart illustrating a first defrosting control method for an air conditioning system provided in this application embodiment. The defrosting control method for the air conditioning system 100 includes the following steps: S1: When the air conditioning system 100 is operating in heating mode, determine whether the air conditioning system 100 meets the defrosting conditions. Specifically, when the air conditioning system 100 is in heating mode, the first valve port 21 and the second valve port 22 of the reversing assembly 2 are connected, the third valve port 23 and the fourth valve port 24 are connected, the first on-off valve 45 is open, the second on-off valve 51 is open, the first throttling valve 43 throttles, the second throttling valve 44 throttles, and the third throttling valve 61 is fully closed.

[0061] S2: If the air conditioning system 100 meets the defrosting conditions, control the first throttle valve 43 to be fully closed and the second on / off valve 51 to be opened, so that the air conditioning system 100 runs the first defrosting mode to defrost the first part 41.

[0062] Therefore, in the first defrost mode, the first valve port 21 and the second valve port 22 of the reversing assembly 2 are kept open, the third valve port 23 and the fourth valve port 24 are kept open, the first throttle valve 43 is fully closed, the second throttle valve 44 is throttled, the first on-off valve 45 is open, the second on-off valve 51 is open, and the third throttle valve 61 is fully closed. At this time, the refrigerant flow direction in the first 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 reversing assembly 2 through the first valve port 21 and flows out of the reversing assembly 2 through the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3 and the defrost branch 5 respectively. The high-temperature, high-pressure gaseous refrigerant flowing to the indoor heat exchanger 3 is condensed into a high-temperature, high-pressure subcooled liquid refrigerant after sufficient heat exchange within the indoor heat exchanger 3. It then flows out of the indoor heat exchanger 3 and into the second throttling valve 44. After being throttled by the second throttling valve 44, it becomes a low-temperature, low-pressure two-phase refrigerant, which then flows to the second section 42. In the second section 42, it evaporates and becomes a low-temperature, low-pressure superheated gaseous refrigerant. The high-temperature, high-pressure gaseous refrigerant flowing to the defrost branch 5 flows into the first section 41, where the sensible heat of the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 1 is used to remove frost from the first section 41. The refrigerant flowing out of the first section 41 and the refrigerant flowing out of the second section 42 flow back to the suction port 11 of the compressor 1 through the third valve port 23 and the fourth valve port 24, respectively.

[0063] S3: Determine whether the air conditioning system 100 meets the conditions for ending the first defrosting mode.

[0064] S4: If the air conditioning system meets the conditions for ending the first defrost mode, control the second throttle valve 44 to be fully open, the first on / off valve 45 to be closed, the second on / off valve 51 to be closed, and the third throttle valve 61 to throttle, so as to control the air conditioning system 100 to exit the first defrost mode and run the second defrost mode. In the second defrost mode, the second part 42 is defrosted.

[0065] Therefore, in the second defrost mode, the first valve port 21 and the second valve port 22 of the reversing assembly 2 are kept open, the third valve port 23 and the fourth valve port 24 are kept open, the first throttle valve 43 is fully closed, the second throttle valve 44 is fully open, the first on-off valve 45 is closed, the second on-off valve 51 is closed, and the third throttle valve 61 is throttled. At this time, the refrigerant flow direction 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 reversing assembly 2 through the first valve port 21 and flows out of the reversing assembly 2 through the second valve port 22. The refrigerant flowing out from the second valve port 22 flows to the indoor heat exchanger 3. The high-temperature, high-pressure gaseous refrigerant undergoes incomplete heat exchange within the indoor heat exchanger 3, transforming into a high-temperature, high-pressure subcooled liquid refrigerant with slight subcooling or a two-phase refrigerant after heat exchange. This refrigerant then flows out of the indoor heat exchanger 3 and towards the second throttling valve 44. After passing through the second throttling valve 44, it flows to the second section 42. Then, the high-temperature, high-pressure subcooled liquid refrigerant with slight subcooling (with waste heat as sensible heat) or the high-temperature, high-pressure two-phase refrigerant (with waste heat as sensible heat) flowing out from the indoor heat exchanger 3 is utilized. The residual heat (sensible heat plus latent heat) is used to defrost the second part 42. After defrosting in the second part 42, the refrigerant flows to the bypass branch 6, and then to the third throttling valve 61 on the bypass branch 6. After being throttled and depressurized by the third throttling valve 61, it becomes a low-temperature, low-pressure two-phase refrigerant. Then it flows back into the first part 41 and evaporates into a low-temperature, 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 third valve port 23 and the fourth valve port 24.

[0066] S5: Determine whether the air conditioning system 100 meets the conditions for ending the second defrosting mode.

[0067] S6: If the conditions for ending the second defrost mode are met, control the first throttle valve 43 to throttle, the second throttle valve 44 to throttle, the first on / off valve 45 to open, the second on / off valve 51 to close, and the third throttle valve 61 to close, so as to exit the second defrost mode and run the heating mode.

[0068] Therefore, when switching from heating mode to the first defrost mode and the second defrost mode for defrosting the first part 41 and the second part 42, the commutation component 2 remains stationary, reducing the power consumption of the air conditioning system 100. Furthermore, the air conditioning system 100 can provide uninterrupted heating, maintaining a consistently high indoor temperature, which improves user comfort. Simultaneously, the first defrost mode utilizes the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 1's exhaust port 12 to defrost the first part 41, resulting in a significant defrosting effect. The second defrost mode utilizes the high-pressure, medium-temperature refrigerant flowing from the indoor heat exchanger 3 to defrost the second part 42. This combined low-pressure sensible heat and high-pressure waste heat defrosting method not only leverages the advantages of both waste heat and sensible heat defrosting but also avoids the significant waste of waste heat defrosting capacity and the poor reliability and narrow applicability of sensible heat defrosting, thus improving the reliability and stability of the air conditioning system 100. Furthermore, when the first part 41 is directly above the second part 42, during the defrosting process of the outdoor heat exchanger assembly 4, by first defrosting the first part 41 and then defrosting the second part 42 after the first part 41 has been defrosted, it is beneficial to ensure the defrosting effect of the outdoor heat exchanger assembly 4. This prevents the problem that if the second part 42 is defrosted first and then the first part 41 is defrosted, the defrosting water droplets from the first part 41 will fall onto the second part 42, which is the evaporator, causing the second part 42 to freeze and resulting in a poor defrosting effect of the second part 42.

[0069] In some embodiments, to improve the evaporation capacity of the first part 41, the outdoor fan 46 is located on the side of the first part 41 away from the second part 42. In step S4, if the air conditioning system meets the end condition of the first defrost mode, the outdoor fan 46 is turned on, thereby blowing air into the first part 41. In this way, after the first part 41 is defrosted, the outdoor fan 46 can improve the evaporation capacity of the first part 41, which in turn can increase the suction pressure of the compressor 1. This allows for rapid airflow to the indoor side after the air conditioning system 100 has completed defrosting, which is beneficial to improving the user experience.

[0070] In some embodiments, before determining that the air conditioning system 100 meets the defrosting conditions, the outdoor ambient 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 acquired. If Ta ≤ a, Te1 / Te2 ≤ b, and the continuous operating time of the air conditioning system 100 in heating mode reaches a first set duration, then the air conditioning system is determined to meet the defrosting conditions. Therefore, the air conditioning system 100 can accurately determine whether to perform defrosting, which helps to improve the sensitivity and reliability of the defrosting function of the air conditioning system 100.

[0071] For example, in Figure 10In the embodiments described above, an outdoor temperature sensor 9 can be installed on the outside of the air conditioning system 100 to obtain the outdoor ambient temperature Ta. A first part Te temperature sensor 411 can be installed at the second end of the first part 41 to obtain the temperature Te1 at the second end of the first part 41. A second part Te temperature sensor 421 can be installed at the second end of the second part 42 to obtain the temperature Te2 at the second end of the second part 42.

[0072] 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.

[0073] In some embodiments, -5℃≤b≤0℃. For example, the value of the Te1 / Te2 ratio can be -5℃, -4℃, -3℃, -2℃, -1℃, or 0℃, etc.

[0074] In some embodiments, the first set duration is ≥10 min. For example, the value of the first set duration can be 10 min, 11 min, 12 min, 13 min, or 14 min, etc.

[0075] In some embodiments, the first defrost mode ends when the temperature Te1 at the second end of the first portion 41 is greater than or equal to f for a first preset time. This allows the first defrost mode to exit promptly when the end condition is met, thereby improving the intelligence and reliability of the air conditioning system 100.

[0076] In some embodiments, the termination condition of the second defrost mode is: the temperature Te2 at the second end of the second part 42 is ≥ f and this condition is maintained for a first preset time. Therefore, the second defrost mode can be exited promptly when the termination condition is met, thereby improving the intelligence and reliability of the air conditioning system 100.

[0077] In some embodiments, 10℃≤f≤25℃. For example, the temperature f at the second end of the second part 42 can be 10℃, 11℃, 12℃, 13℃, 14℃, 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃ or 25℃, etc.

[0078] In some embodiments, 5 seconds ≤ first preset time ≤ 30 seconds. For example, the value of the first preset time can be 5 seconds, 10 seconds, 15 seconds, 20 seconds, 25 seconds, or 30 seconds, etc.

[0079] In some embodiments, the opening degree of the second throttle valve 44 is adjustable. During defrosting of the first portion 41, the opening degree of the second throttle valve 44 is adjusted to meet a first preset condition. The first preset condition is: the suction superheat of compressor 1 satisfies: Tssh ≥ d, and the discharge superheat of compressor 1 satisfies: Tdsh ≥ e; where 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. This setting can improve the accuracy of the opening degree control of the second throttle valve 44, thereby improving 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 compressor 1, and Tc_pd is the saturation temperature corresponding to the discharge pressure Pd at the discharge port 12.

[0080] For example, in Figure 10 In the described embodiment, a second part temperature sensor 422 can be provided at the first end of the second part 42 to obtain the temperature Tg2 of the first end of the second part 42. A suction pressure sensor 111 can be provided at the suction port 11 of the compressor 1 to detect the suction pressure Ps. An exhaust pressure sensor 121 can be provided at the exhaust port 12 of the compressor 1 to detect the exhaust pressure Pd. An exhaust temperature sensor 122 can be provided at the exhaust port 12 of the compressor 1 to detect the exhaust temperature Td.

[0081] In some embodiments, the opening of the third throttle valve 61 is adjustable. 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: the suction superheat of the compressor 1 satisfies: Tssh≥d, and the discharge superheat of the compressor 1 satisfies: 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.

[0082] For example, in Figure 10 In the embodiment described above, a first part temperature sensor 412 may be provided at the first end of the first part 41 to obtain the temperature Tg1 at the first end of the second part 42.

[0083] 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℃.

[0084] In some embodiments, 20℃≤e≤40℃. For example, the value of e can be 20℃, 25℃, 30℃, 35℃, or 40℃, etc.

[0085] In some embodiments, when defrosting the second section 42, the indoor fan of the air conditioning system 100 is controlled to stop operating or operate at the lowest fan speed. This setting ensures that the refrigerant flowing into the second section 42 has residual heat in the second defrosting mode, thereby ensuring the defrosting efficiency of the second section 42.

[0086] The defrosting control method of the air conditioning system 100 according to the second embodiment of this application will be described below.

[0087] Please see Figure 12 , Figure 12 A flowchart illustrating a second defrosting control method for an air conditioning system provided in this application embodiment. The defrosting control method for the air conditioning system 100 includes the following steps: S1: When the air conditioning system 100 is operating in heating mode, determine whether the air conditioning system 100 meets the defrosting conditions. Specifically, when the air conditioning system 100 is in heating mode, the first valve port 21 and the second valve port 22 of the reversing assembly 2 are connected, the third valve port 23 and the fourth valve port 24 are connected, the first on-off valve 45 is open, the second on-off valve 51 is open, the first throttling valve 43 throttles, the second throttling valve 44 throttles, and the third throttling valve 61 is fully closed.

[0088] S2: If the air conditioning system 100 meets the defrosting conditions, control the first throttle valve 43 to be fully closed, the second throttle valve 44 to be fully open, the first on / off valve 45 to be closed, and the third throttle valve 61 to throttle, so that the air conditioning system 100 runs the first defrosting mode to defrost the second part 42.

[0089] Therefore, in the first defrost mode, the first valve port 21 and the second valve port 22 of the reversing assembly 2 are kept open, the third valve port 23 and the fourth valve port 24 are kept open, the first throttle valve 43 is fully closed, the second throttle valve 44 is fully open, the first on-off valve 45 is fully closed, the second on-off valve 51 is closed, and the third throttle valve 61 throttles. At this time, the high-temperature and high-pressure gaseous refrigerant discharged from the discharge port 12 of the compressor 1 flows into the reversing assembly 2 through the first valve port 21 and flows out of the reversing assembly 2 through the second valve port 22. The refrigerant flowing out from the second valve port 22 flows to the indoor heat exchanger 3. The high-temperature, high-pressure gaseous refrigerant undergoes incomplete heat exchange within the indoor heat exchanger 3, transforming into a high-temperature, high-pressure subcooled liquid refrigerant with slight subcooling or a two-phase refrigerant after heat exchange. This refrigerant then flows out of the indoor heat exchanger 3 and towards the second throttling valve 44. After passing through the second throttling valve 44, it flows to the second section 42, where the high-temperature, high-pressure subcooled liquid refrigerant (with waste heat as sensible heat) or the high-temperature, high-pressure two-phase refrigerant (with waste heat) flowing out from the indoor heat exchanger 3 is utilized. The residual heat (sensible heat plus latent heat) is used to defrost the second part 42. After defrosting in the second part 42, the refrigerant flows to the bypass branch 6, and then to the third throttling valve 61 on the bypass branch 6. After being throttled and depressurized by the third throttling valve 61, it becomes a low-temperature and low-pressure two-phase refrigerant. Then it flows back into the first part 41 and evaporates into a 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 third valve port 23 and the fourth valve port 24.

[0090] S3: Determine whether the air conditioning system 100 meets the conditions for ending the first defrosting mode.

[0091] S4: If the air conditioning system meets the conditions for ending the first defrost mode, control the second throttle valve 44 to throttle, the first on / off valve 45 to open, the second on / off valve 51 to open, and the third throttle valve 61 to fully close, so as to control the air conditioning system 100 to exit the first defrost mode and run the second defrost mode. In the second defrost mode, the first part 41 is defrosted.

[0092] Therefore, in the second defrost mode, the first valve port 21 and the second valve port 22 of the reversing assembly 2 are kept open, the third valve port 23 and the fourth valve port 24 are kept open, the first throttle valve 43 is fully closed, the second throttle valve 44 is throttled, the first on-off valve 45 is open, the second on-off valve 51 is open, and the third throttle valve 61 is fully closed. At this time, the high-temperature and high-pressure gaseous refrigerant discharged from the exhaust port 12 of the compressor 1 flows into the reversing assembly 2 through the first valve port 21 and flows out of the reversing assembly 2 through the second valve port 22. The refrigerant flowing out of the second valve port 22 flows to the indoor heat exchanger 3 and the defrost branch 5 respectively. The high-temperature, high-pressure gaseous refrigerant flowing to the indoor heat exchanger 3 is condensed into a high-temperature, high-pressure subcooled liquid refrigerant after sufficient heat exchange within the indoor heat exchanger 3. It then flows out of the indoor heat exchanger 3 and into the second throttling valve 44. After being throttled by the second throttling valve 44, it becomes a low-temperature, low-pressure two-phase refrigerant, which then flows to the second section 42. In the second section 42, it evaporates and becomes a low-temperature, low-pressure superheated gaseous refrigerant. The high-temperature, high-pressure gaseous refrigerant flowing to the defrost branch 5 flows into the first section 41, where the sensible heat of the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 1 is used to remove frost from the first section 41. The refrigerant flowing out of the first section 41 and the refrigerant flowing out of the second section 42 flow back to the suction port 11 of the compressor 1 through the third valve port 23 and the fourth valve port 24, respectively.

[0093] S5: Determine whether the air conditioning system 100 meets the conditions for ending the second defrosting mode.

[0094] S6: If the conditions for ending the second defrost mode are met, control the first throttle valve 43 to throttle, the second throttle valve 44 to throttle, the first on / off valve 45 to open, the second on / off valve 51 to close, and the third throttle valve 61 to close, so as to exit the second defrost mode and run the heating mode.

[0095] Therefore, when switching from heating mode to the first defrost mode and the second defrost mode for defrosting the first part 41 and the second part 42, the commutation component 2 remains stationary, reducing the power consumption of the air conditioning system 100. Furthermore, the air conditioning system 100 can provide uninterrupted heating, maintaining a consistently high indoor temperature, which improves user comfort. Simultaneously, the second defrost mode utilizes the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 1's exhaust port 12 to defrost the first part 41, resulting in a significant defrosting effect. The first defrost mode utilizes the high-pressure, medium-temperature refrigerant flowing from the indoor heat exchanger 3 to defrost the second part 42. This combined low-pressure sensible heat and high-pressure waste heat defrosting method not only leverages the advantages of both waste heat and sensible heat defrosting but also avoids the significant waste of waste heat defrosting capacity and the poor reliability and narrow applicability of sensible heat defrosting, thus improving the reliability and stability of the air conditioning system 100. Furthermore, when the second part 42 is located directly above the first part 41, during the defrosting process of the outdoor heat exchanger assembly 4, by first defrosting the second part 42 and then defrosting the first part 41 after the second part 42 has been defrosted, it is beneficial to ensure the defrosting effect of the outdoor heat exchanger assembly 4. This prevents the problem that if the first part 41 is defrosted first and then the second part 42 is defrosted, the defrosting water droplets from the second part 42 will fall onto the first part 41, which is the evaporator, causing the first part 41 to freeze and resulting in a poor defrosting effect of the first part 41.

[0096] In some embodiments, to improve the evaporation capacity of the second part 42, an outdoor fan 46 is positioned on the side of the second part 42 away from the first part 41. In step S4, if the air conditioning system meets the conditions for ending the first defrost mode, the outdoor fan 46 is turned on, thereby supplying air to the second part 42. Thus, after the second part 42 has finished defrosting, the activation of the outdoor fan 46 can improve the evaporation capacity of the second part 42, thereby increasing the suction pressure of the compressor 1. This allows for rapid airflow to the indoor side after the air conditioning system 100 has completed defrosting, improving the user experience.

[0097] In some embodiments, before determining that the air conditioning system 100 meets the defrosting conditions, the outdoor ambient 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 acquired. If Ta ≤ a, Te1 / Te2 ≤ b, and the continuous operating time of the air conditioning system 100 in heating mode reaches a first preset duration, then the air conditioning system is determined to meet the defrosting conditions. Therefore, the air conditioning system 100 can be prepared to determine whether to perform defrosting, which helps to improve the sensitivity and reliability of the defrosting function of the air conditioning system 100.

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

[0099] 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.

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

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

[0102] In some embodiments, the first defrost mode ends when the temperature Te2 at the second end of the second part 42 is greater than or equal to f for a first preset time. This allows the first defrost mode to exit promptly when the end condition is met, thereby improving the intelligence and reliability of the air conditioning system 100.

[0103] In some embodiments, the termination condition of the second defrost mode is: the temperature Te1 at the second end of the first part 41 is ≥ f and this temperature persists for a first preset time. Therefore, the second defrost mode can be exited promptly when the termination condition is met, thereby improving the intelligence and reliability of the air conditioning system 100.

[0104] In some embodiments, 10℃≤f≤25℃. For example, the temperature f at the second end of the second part 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 ≤ first preset time ≤ 30 seconds. For example, the value of 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 degree of the second throttle valve 44 is adjustable. During defrosting of the first portion 41, the opening degree of the second throttle valve 44 is adjusted to meet a first preset condition. The first preset condition is: the suction superheat of compressor 1 satisfies: Tssh ≥ d, and the discharge superheat of compressor 1 satisfies: Tdsh ≥ e; where 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. This setting can improve the accuracy of the opening degree control of the second throttle valve 44, thereby improving 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 compressor 1, and Tc_pd is the saturation temperature corresponding to the discharge pressure Pd at the discharge port 12.

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

[0108] In some embodiments, the opening of the third throttle valve 61 is adjustable. 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: the suction superheat of the compressor 1 satisfies: Tssh≥d, and the discharge superheat of the compressor 1 satisfies: 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.

[0109] For example, in Figure 10 In the embodiment described above, a first part temperature sensor 412 may be provided at the first end of the first part 41 to obtain the temperature Tg1 at the first end of the second part 42.

[0110] 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℃.

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

[0112] In some embodiments, when defrosting the second section 42, the indoor fan of the air conditioning system 100 is controlled to stop operating or operate at the lowest fan speed. This setting ensures that the refrigerant flowing into the second section 42 has residual heat in the second defrosting mode, thereby ensuring the defrosting efficiency of the second section 42.

[0113] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0114] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An air conditioner, characterized in that, include: Indoor unit, which has an indoor heat exchanger; An outdoor unit, which includes an outdoor heat exchanger, the outdoor heat exchanger comprising a first part and a second part; The indoor heat exchanger is connected to the outdoor heat exchanger via gas-side piping and liquid-side piping. The compressor has an exhaust port and an intake port; A defrosting branch, wherein the first end of the defrosting branch is connected to the exhaust port, and the second end of the defrosting branch is connected to the second end of the first part; A bypass branch, wherein the first end of the bypass branch is connected to the first end of the second part, and the second end of the bypass branch is connected to the second end of the first part; The second end of the first part and the second end of the second part are respectively connected to the liquid-side piping via a first connecting pipe and a second connecting pipe; The reversing assembly has a first to a fourth valve port, the first valve port being connected to the exhaust port and the fourth valve port being connected to the intake port; The first end of the indoor heat exchanger is connected to the second valve port; The first end of the first part is connected to the third valve port, the first end of the second part is connected in series with the third valve port, the second end of the first part is connected with the second end of the indoor heat exchanger with a first throttling valve, and the second end of the second part is connected with the second end of the indoor heat exchanger with a second throttling valve. The first throttle valve is placed on the first connecting pipeline, the second throttle valve is placed on the second connecting pipeline, the third throttle valve is connected in series on the bypass branch, and the second on / off valve is connected in series on the defrost branch; The first part uses the sensible heat of the refrigerant for defrosting, and the second part uses the residual heat of the refrigerant for defrosting; wherein the sensible heat defrosting and the residual heat defrosting are not performed simultaneously.

2. The air conditioner according to claim 1, characterized in that, When the first part uses the sensible heat of the refrigerant for defrosting, the first part and the second part are connected in parallel.

3. The air conditioner according to claim 1, characterized in that, When the second part uses the residual heat of the refrigerant for defrosting, the first part and the second part are connected in series.

4. The air conditioner according to claim 1, characterized in that, Also includes: An outdoor fan is installed on one side of the outdoor heat exchanger; When the first part uses the sensible heat of the refrigerant for defrosting, the outdoor fan operates to improve the evaporation capacity of the first part.

5. The air conditioner according to claim 1, characterized in that, Also includes: An indoor fan is installed on one side of the indoor heat exchanger; When the second part uses refrigerant waste heat for defrosting, the indoor fan stops, and the refrigerant waste heat defrosting is sensible heat and latent heat defrosting; or the indoor fan operates at a speed not lower than the upper limit, and the refrigerant waste heat defrosting is sensible heat defrosting.

6. The air conditioner according to claim 1, characterized in that, The first part is located directly above the second part; or, the first part is located directly below the second part.

7. The air conditioner according to claim 1, characterized in that, The first throttle valve, the second throttle valve, and the third throttle valve are all electronic expansion valves.

8. The air conditioner according to claim 7, characterized in that, 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.

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