Method and device for controlling oil return of air conditioner compressor, air conditioner and storage medium

Abstract

The application discloses a method for controlling oil return of an air conditioner compressor, the air conditioner comprising a throttling heat exchanger, the throttling heat exchanger comprising a plurality of heat exchange branches, the air conditioner further comprising a first refrigerant circulation loop and a second refrigerant circulation loop sharing the throttling heat exchanger, and the plurality of heat exchange branches being capable of being switched between a parallel connection state and a series connection state by switching on and off states of the first refrigerant circulation loop and the second refrigerant circulation loop; the method comprising: in response to a compressor oil return instruction, controlling the compressor to operate at a high frequency; comparing current states of the plurality of heat exchange branches with preset states; and in the case that the current states are different from the preset states, controlling the on and off states of the first refrigerant circulation loop and the second refrigerant circulation loop so that the states of the plurality of heat exchange branches meet the preset states. The preset states can make the condenser at a higher temperature, so that the compressor can quickly return oil. The application further discloses a device for controlling oil return of an air conditioner compressor, an air conditioner and a storage medium.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent household appliances, for example to a method and device for controlling oil return of an air conditioner compressor, an air conditioner and a storage medium. BACKGROUND

[0002] The compressor is a core component of the air conditioner. When the compressor is running, it needs to have enough oil for lubrication to reduce the wear of the compressor. Therefore, the oil return speed and effect of the compressor will affect the running state of the compressor.

[0003] In the related art, a variable frequency air conditioner oil return control method is disclosed, including the steps of: accumulating a first operation duration when the running frequency of the compressor is less than a first preset frequency; when the accumulated first operation duration is greater than or equal to a first preset duration, if the condensing temperature of the air conditioner is less than or equal to a first preset temperature, controlling the compressor to start oil return; after controlling the compressor to start oil return, when the condensing temperature is greater than the first preset temperature, controlling the compressor to suspend oil return until the condensing temperature is less than a condensing limit temperature, and then controlling the compressor to restart oil return; when the accumulated duration of the compressor performing oil return reaches a second preset duration, controlling the compressor to end oil return.

[0004] In the above method, the air conditioner is kept for a long enough time in the oil return operation to make the oil return thorough and the oil return effect good. However, the oil return operation time is too long, which will affect the normal operation of the air conditioner. SUMMARY

[0005] The following presents a simplified summary of some aspects of the disclosed embodiments in order to provide a basic understanding of such embodiments. The summary is not an extensive overview of the disclosure and is not intended to identify key / critical elements of the embodiments or to delineate the scope of the embodiments. Its sole purpose is to present some aspects of the disclosed embodiments in a simplified form as a prelude to the more detailed description that is presented later.

[0006] The embodiments of the present disclosure provide a method and device for controlling oil return of an air conditioner compressor, an air conditioner and a storage medium to improve the oil return speed of the compressor.

[0007] In some embodiments, the air conditioner comprises a throttling heat exchanger, the throttling heat exchanger comprises a plurality of heat exchange branches, the air conditioner further comprises a first refrigerant circulation loop and a second refrigerant circulation loop sharing the throttling heat exchanger, by switching the on-off state of the first refrigerant circulation loop and the second refrigerant circulation loop, each heat exchange branch can be switched between parallel connection and series connection, the method comprises: in response to a compressor oil return instruction, controlling the compressor to operate at a higher frequency; comparing the current state of each heat exchange branch with a preset state; in the case that the current state is different from the preset state, controlling the on-off state of the first refrigerant circulation loop and the second refrigerant circulation loop to make the state of each heat exchange branch meet the preset state.

[0008] In some embodiments, the device comprises a processor and a memory storing program instructions, the processor is configured to execute the foregoing method for controlling compressor oil return of an air conditioner when running the program instructions.

[0009] In some embodiments, the air conditioner comprises a throttling heat exchanger, the throttling heat exchanger comprises a plurality of heat exchange branches, the air conditioner further comprises a first refrigerant circulation loop and a second refrigerant circulation loop sharing the throttling heat exchanger, by switching the on-off state of the first refrigerant circulation loop and the second refrigerant circulation loop, each heat exchange branch can be switched between parallel connection and series connection, and the foregoing device for controlling compressor oil return of an air conditioner.

[0010] In some embodiments, the storage medium stores program instructions, the program instructions execute the foregoing method for controlling compressor oil return of an air conditioner when running.

[0011] The method, device, air conditioner and storage medium for controlling compressor oil return of an air conditioner provided by the embodiments of the present disclosure can achieve the following technical effects:

[0012] In the process of compressor oil return, it is judged whether the current state of each heat exchange branch is the same as the preset state. If not, the on-off state of the first refrigerant circulation loop and the second refrigerant circulation loop is controlled to make the state of each heat exchange branch meet the preset state. The preset state can make the condenser be in a higher temperature state, so as to make the compressor quickly return oil. The influence of slow compressor oil return speed or too long oil return time on normal operation of the air conditioner is reduced.

[0013] The foregoing general description and the following description are only exemplary and explanatory, and are not used to limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0014] One or more embodiments are illustrated by way of example in the figures that are not intended to be limiting of the embodiments. Like numbers refer to like elements throughout the drawings, which are not necessarily to scale, and in which:

[0015] Figure 1 is a structural schematic diagram of a throttling heat exchanger provided by an embodiment of the present disclosure;

[0016] Figure 2 is a refrigerant flow schematic diagram of an air conditioner in a heating operating mode, the throttling heat exchanger as an outdoor heat exchanger provided by an embodiment of the present disclosure;

[0017] Figure 3 is a refrigerant flow schematic diagram of an air conditioner in a cooling operating mode, the throttling heat exchanger as an outdoor heat exchanger provided by an embodiment of the present disclosure;

[0018] Figure 4 is a structural schematic diagram of a first distributor provided by an embodiment of the present disclosure;

[0019] Figure 5 is a structural schematic diagram of another first distributor provided by an embodiment of the present disclosure;

[0020] Figure 6 is a refrigerant flow schematic diagram of an air conditioner in a first refrigerant circulation loop communication provided by an embodiment of the present disclosure;

[0021] Figure 7 is a refrigerant flow schematic diagram of an air conditioner in a second refrigerant circulation loop communication provided by an embodiment of the present disclosure;

[0022] Figure 8 is a schematic diagram of one method for controlling an air conditioner compressor oil return provided by an embodiment of the present disclosure;

[0023] Figure 9 is a schematic diagram of another method for controlling an air conditioner compressor oil return provided by an embodiment of the present disclosure;

[0024] Figure 10 is a schematic diagram of another method for controlling an air conditioner compressor oil return provided by an embodiment of the present disclosure;

[0025] Figure 11 is a schematic diagram of another method for controlling an air conditioner compressor oil return provided by an embodiment of the present disclosure;

[0026] Figure 12 is an application schematic diagram provided by an embodiment of the present disclosure;

[0027] Figure 13 is a schematic diagram of a device for controlling an air conditioner compressor oil return provided by an embodiment of the present disclosure;

[0028] Figure 14 is another schematic view of a device for controlling oil return of a compressor of an air conditioner provided by the embodiments of the present disclosure.

[0029] Reference signs:

[0030] 1, compressor; 2, outdoor heat exchanger; 3, indoor heat exchanger; 4, first pipeline; 5, second pipeline; 6, third pipeline; 7, fourth pipeline; 8, fifth pipeline; 9, first on-off valve; 10, second on-off valve; 11, third on-off valve; 12, fourth on-off valve; 13, throttling device;

[0031] 200, throttling heat exchanger; 210, heat exchange pipeline; 211, first heat exchange branch; 212, second heat exchange branch; 213, third heat exchange branch; 221, first distributor; 222, second distributor; 223, third distributor; 224, fourth distributor; 2211, first distribution branch pipe; 2212, second distribution branch pipe; 2213, collecting pipe; 2214, collecting cavity; 2215, first branch cavity; 2216, second branch cavity; 2217, first pipe section; 2218, second pipe section; 231, first throttling element; 232, second throttling element; 240, bypass pipeline; 241, electromagnetic valve. DETAILED DESCRIPTION

[0032] In order to enable a more detailed understanding of the features and technical content of the embodiments of the present disclosure, the implementation of the embodiments of the present disclosure is described in detail below, and the attached drawings are only used for reference and do not limit the embodiments of the present disclosure. In the following technical description, in order to facilitate explanation, through multiple details, a sufficient understanding of the disclosed embodiments is provided. However, one or more embodiments can still be implemented without these details. In other cases, in order to simplify the drawings, well-known structures and devices can be simplified.

[0033] The terms "first", "second", and the like in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present disclosure described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0034] Unless otherwise specified, the term "a plurality of" means two or more.

[0035] In the embodiments of the present disclosure, the character " / " represents an "or" relationship between the objects before and after it. For example, A / B represents: A or B.

[0036] The term "and / or" is a descriptive term that refers to an association relationship, which means that there can be three relationships. For example, A and / or B means that there are three relationships of A or B, or A and B.

[0037] The term "corresponds to" can refer to an association relationship or a binding relationship. A corresponds to B means that there is an association relationship or a binding relationship between A and B.

[0038] The air conditioner includes an indoor unit and an outdoor unit. The indoor unit is provided with an indoor heat exchanger, an indoor fan and the like, which can be used to realize the function of heat exchange with the indoor environment in cooperation with the refrigerant. The outdoor unit is provided with an outdoor heat exchanger, an outdoor fan, a compressor and a gas-liquid separator, which can be used to realize the functions of heat exchange with the outdoor environment, refrigerant compression, refrigerant throttling and the like in cooperation with the refrigerant.

[0039] The indoor heat exchanger, the outdoor heat exchanger, the compressor and the gas-liquid separator are connected by the refrigerant pipeline to jointly constitute a refrigerant circulation system for circulating and conveying the refrigerant between the indoor and outdoor units. The optimal flow path required by the outdoor heat exchanger is different when the air conditioner is running in a cooling condition and a heating condition. The throttling heat exchanger of the present embodiment realizes that the heat exchange branch of the throttling heat exchanger is less when the air conditioner is running in a cooling condition, and at the same time, the heat exchange branch of the throttling heat exchanger is more when the air conditioner is running in a heating condition. The throttling heat exchanger realizes the variable flow of the refrigerant flow path, which can simultaneously make the air conditioner have the optimal flow path in the cooling condition and the heating condition. Figure 2 and Figure 3 as shown.

[0040] In combination with Figure 1 as shown, the present embodiment simultaneously provides a throttling heat exchanger. The throttling heat exchanger 200 includes a heat exchange pipeline 210, a first distributor 221 and a throttling element. The heat exchange pipeline 210 includes a plurality of heat exchange branches connected in parallel. The first distributor 221 includes a main pipe and a plurality of branch pipes. The plurality of branch pipes are connected in communication with the plurality of heat exchange branches. The throttling element is arranged between the heat exchange branch and the first distributor 221 to throttle the refrigerant after being distributed by the first distributor 221 and before entering the heat exchange branch.

[0041] It can be understood that, in combination with Figure 2 and Figure 3 as shown, when the flow direction of the refrigerant in the throttling heat exchanger 200 is different, the connection form of each heat exchange branch is also different, which specifically shows that the plurality of heat exchange branches are connected in parallel and in communication, or the heat exchange branches are reduced. In this way, the variable flow of the throttling heat exchanger 200 is realized.

[0042] As Figure 1As shown, the throttling heat exchanger 200 provided by the embodiments of the present disclosure is provided with a throttling element between the heat exchange branch and the first distributor 221, which can throttle the refrigerant after being distributed by the first distributor 221 and before entering the heat exchange branch. That is, the refrigerant flowing into the outdoor heat exchanger is not throttled before being distributed by the first distributor 221, at this time, the liquid content of the refrigerant entering the first distributor 221 is relatively high, which improves the distribution uniformity of the first distributor 221, and further improves the heat exchange uniformity of the throttling heat exchanger 200.

[0043] Optionally, the first distributor 221 includes a first distribution branch pipe 2211 and a second distribution branch pipe 2212. The first distribution branch pipe 2211 is in communication with one or more heat exchange branches, and the second distribution branch pipe 2212 is in communication with one or more heat exchange branches. The first distribution branch pipe 2211 is provided with a first throttling element 231, and the second distribution branch pipe 2212 is provided with a second throttling element.

[0044] A throttling element is arranged at each distribution branch pipe of the first distributor 221 to throttle the refrigerant flowing out of the different distribution branch pipes, respectively. For example, Figure 1 As shown.

[0045] Optionally, the heat exchange pipeline 210 includes an upper heat exchange pipeline and a lower heat exchange pipeline. The upper heat exchange pipeline includes a first heat exchange branch 211 and a second heat exchange branch 212 in communication, and the lower heat exchange pipeline includes a third heat exchange branch 213. The refrigerant outlet of the first heat exchange branch 211 and the second heat exchange branch 212 is in communication with the second distributor 222, the refrigerant inlet of the second heat exchange branch 212 and the third heat exchange branch 213 is in communication with the third distributor 223, and the refrigerant inlet of the first heat exchange branch 211 is in communication with the fourth distributor 224. The first throttling element 231 is arranged between the first distribution branch pipe 2211 and the second distributor 222, and the second throttling element 232 is arranged between the second distribution branch pipe 2212 and the third heat exchange branch 213. Optionally, the throttling heat exchanger 200 further includes a bypass pipeline 240. The bypass pipeline 240 is in communication with the third distributor 223 and the fourth distributor 224, and the bypass pipeline 240 is provided with an electromagnetic valve 241.

[0046] When the air conditioner operates in a heating condition and the throttling heat exchanger 200 is used as an outdoor heat exchanger, the refrigerant flow path in the throttling heat exchanger 200 is as follows, Figure 2As shown in the figure. Control the electromagnetic valve 241 between the fourth distributor 224 and the third distributor 223 to be on, at the same time, control the electronic expansion valve between the second distributor 222 and the first distribution branch pipe 2211 to be on. Specifically, the low-temperature and low-pressure refrigerant enters the first distributor 221 through the main pipe of the throttling heat exchanger 200, and is distributed into the first throttling element 231 and the second throttling element 232 respectively. The refrigerant after the first throttling element 231 enters the first heat exchange branch 211 and the second heat exchange branch 212 respectively through the second distributor 222 for heat exchange, and the refrigerant after the second throttling element 232 enters the third heat exchange branch 213 for heat exchange. The second heat exchange branch 212 and the third heat exchange branch 213 are connected in parallel after heat exchange, and further flow out through the fourth distributor 224; the first heat exchange branch 211 is connected in parallel after heat exchange and flows out through the fourth distributor 224. That is, the first heat exchange branch 211, the second heat exchange branch 212 and the third heat exchange branch 213 are in parallel connection state under heating condition.

[0047] When the air conditioner runs in refrigeration condition and the throttling heat exchanger 200 is used as an outdoor heat exchanger, the flow path of the refrigerant in the throttling heat exchanger 200 is as shown in the figure. Figure 3 As shown in the figure. Control the electromagnetic valve 241 between the fourth distributor 224 and the third distributor 223 to be on, at the same time, control the electronic expansion valve between the second distributor 222 and the first distribution branch pipe 2211 to be on. Specifically, the low-temperature and low-pressure refrigerant enters the first distributor 221 through the main pipe of the throttling heat exchanger 200, and is distributed into the first throttling element 231 and the second throttling element 232 respectively. The refrigerant after the first throttling element 231 enters the first heat exchange branch 211 and the second heat exchange branch 212 respectively through the second distributor 222 for heat exchange, and the refrigerant after the second throttling element 232 enters the third heat exchange branch 213 for heat exchange. The second heat exchange branch 212 and the third heat exchange branch 213 are connected in parallel after heat exchange, and further flow out through the fourth distributor 224; the first heat exchange branch 211 is connected in parallel after heat exchange and flows out through the fourth distributor 224. That is, the first heat exchange branch 211, the second heat exchange branch 212 and the third heat exchange branch 213 are in parallel connection state under heating condition.

[0048] Optionally, the first throttling element 231 is an electronic expansion valve. In this way, the flow path of the refrigerant in the throttling heat exchanger 200 can be changed by controlling the on or off of the electronic expansion valve.

[0049] In order to realize the variable distribution of the outdoor heat exchanger, the position of the electronic expansion valve can also be provided with a one-way valve. Optionally, the second throttling element 232 is a capillary tube.

[0050] Optionally, the first distributor comprises a housing and a manifold 2213. The housing has a distribution cavity inside, and the housing is provided with a first distribution port and a second distribution port. The manifold 2213 comprises a first pipe segment 2217 and a second pipe segment 2218 which are communicated by bending. The first pipe segment 2217 is directly communicated with the distribution cavity. The first distribution branch pipe 2211 is communicated with the distribution cavity through the first distribution port, and the second distribution branch pipe 2212 is communicated with the distribution cavity through the second distribution port. As shown in Figure 4 and Figure 5 .

[0051] Optionally, the distribution cavity comprises a manifold cavity 2214, a first branch cavity 2215 and a second branch cavity 2216. The first distribution branch pipe 2211 is communicated with the first branch cavity 2215 through the first distribution port, and the second distribution branch pipe 2212 is communicated with the second branch cavity 2216 through the second distribution port.

[0052] The manifold 2213 comprises the first pipe segment 2217 and the second pipe segment 2218. The axes of the first pipe segment 2217 and the second pipe segment 2218 are located in a first plane, and the included angle between the first plane and the second plane is e. As shown in Figure 5 . The first plane is non-perpendicular to the second plane, which can be understood as that the included angle e between the first plane and the second plane is less than 90°. Optionally, the included angle between the first plane and the second plane is measured by the acute angle formed by the two planes. The first plane is non-perpendicular to the second plane, so that the amount of refrigerant entering the first distribution branch pipe 2211 and the second distribution branch pipe 2212 through the first pipe segment 2217 is different. For example, when the included angle between the first plane and the second plane is on the side of the first distribution branch pipe 2211, under the action of gravity, the flow rate of the refrigerant flowing to the second distribution branch pipe 2212 is greater than the flow rate of the refrigerant flowing to the first distribution branch pipe 2211. Similarly, when the included angle between the first plane and the second plane is on the side of the second distribution branch pipe 2212, under the action of gravity, the flow rate of the refrigerant flowing to the first distribution branch pipe 2211 is greater than the flow rate of the refrigerant flowing to the second distribution branch pipe 2212.

[0053] As shown in the throttling heat exchanger, Figure 2 , the refrigerant is divided by the first distributor 221 and flows into three parallel heat exchange branches. Among them, as shown in the direction of Figure 2 , the refrigerant flows into only the third heat exchange branch 213 after passing through the distribution branch pipe on the left side of the first distributor 221, and the refrigerant flows into two heat exchange branches after passing through the distribution branch pipe on the right side of the first distributor 221. It can be seen that the amount of refrigerant required by the two distribution branch pipes of the first distributor 221 is different after the refrigerant passes through the first distributor 221. As shown in Figure 2In the throttling heat exchanger shown, the amount of refrigerant required for the right branch pipe is approximately twice the amount of refrigerant required for the left branch pipe. The liquid separator provided by the embodiment of the present disclosure utilizes the gravity of the refrigerant during the flow process. By setting the angle between the first plane where the axes of the first pipe section 2217 and the second pipe section 2218 of the manifold 2213 are located and the second plane where the axes of the first branch pipe 2211 and the second branch pipe 2212 are located, the amount of refrigerant flowing out of different branch pipes of the liquid separator is different, thereby meeting the different requirements for the amount of refrigerant required by the branch pipes, thereby improving the heat exchange efficiency of the throttling heat exchanger.

[0054] Optionally, the angle between the first plane and the second plane is less than 90 degrees, so that after the refrigerant flows through the first pipe section 2217 of the conduit 2213, it is biased under the action of gravity, thereby making the amount of cooling flowing into the first liquid branch 2211 and the second liquid branch 2212 different.

[0055] Optionally, the inner diameter of the first pipe section 2217 of the manifold 2213 is larger than the inner diameter of the first liquid branch pipe 2211 .

[0056] Optionally, the inner diameter of the first liquid branch pipe 2211 is larger than the inner diameter of the second liquid branch pipe 2212. Optionally, the first pipe section 2217 of the confluence pipe 2213 is tilted toward the second liquid branch pipe 2212. Then, under the action of gravity, the inner diameter of the first liquid branch pipe 2211 is further larger than the inner diameter of the second liquid branch pipe 2212, allowing more refrigerant to flow into the first liquid branch pipe 2211, further increasing the refrigerant flow difference between the two liquid branch pipes.

[0057] By setting an angle between the first plane where the axes of the first pipe section 2217 and the second pipe section 2218 of the manifold 2213 are located and the second plane where the axes of the two liquid branch pipes are located, and further coordinating the technical solution of the inner diameter difference between the two liquid branch pipes, within the range allowed by the diameter of the heat exchange tube of the heat exchanger, the refrigerant flow ratio of the two liquid branch pipes can be 2:1-7:1, or even a larger ratio of refrigerant distribution requirements can be achieved. The inner diameter of the second liquid branch pipe 2212 does not need to be designed to be too thin, and the flow rate of the refrigerant in the first liquid branch pipe 2211 can also be achieved to be much larger than the flow rate of the refrigerant in the second liquid branch pipe 2212. Therefore, the refrigerant distribution scheme of the liquid distributor provided in the embodiment of the present disclosure avoids the problem of excessive total pressure drop of the liquid branch pipes and the heat exchanger of the liquid distributor when the refrigerant distribution of the two liquid branch pipes is relatively large.

[0058] Optionally, an angle between a first plane where the axes of the first and second sections 2217 and 2218 of the manifold 2213 lie and a second plane where the axes of the two liquid branch pipes lie is greater than or equal to 50 degrees and less than or equal to 70 degrees. This increases the difference in refrigerant flow rates between the first and second liquid branch pipes 2211 and 2212.

[0059] Optionally, the second pipe section 2218 of the manifold pipe 2213 is arranged to be inclined to the second distribution branch pipe 2212.

[0060] In combination Figure 6 and Figure 7 As shown in FIG. 1, the air conditioner provided by the embodiment of the present disclosure includes a first refrigerant circulation loop and a second refrigerant circulation loop.

[0061] The compressor 1 is connected to the fourth distributor 224 of the throttling heat exchanger 200 through a first pipe 4. The first distributor 221 is connected to the indoor heat exchanger 3 through a second pipe 5. The indoor heat exchanger 3 is connected to the compressor 1 through a third pipe 6. In this way, the compressor 1, the first pipe 4, the throttling heat exchanger 200, the second pipe 5, the indoor heat exchanger 3 and the third pipe 6 form the first refrigerant circulation loop.

[0062] A first end of a fourth pipe 7 is connected to a first position on the first pipe 4, and a second end is connected to a second position on the second pipe 5. A first end of a fifth pipe 8 is connected to a third position on the first pipe 4, and a second end is connected to a fourth position on the second pipe 5. In this way, the compressor 1, the fourth pipe 7, the throttling heat exchanger 200, the fifth pipe 8, the indoor heat exchanger 3 and the third pipe 6 form the second refrigerant circulation loop.

[0063] A first on-off valve 9 is arranged on the first pipe 4, and the first on-off valve 9 is located between the first position and the third position. A second on-off valve 10 is arranged on the second pipe 5, and the second on-off valve 10 is located between the second position and the fourth position. A third on-off valve 11 is arranged on the fourth pipe 7. A fourth on-off valve 12 is arranged on the fifth pipe 8. By switching the on-off state of the first refrigerant circulation loop and the second refrigerant circulation loop, the heat exchange branches can be switched between the parallel connection state and the series connection state.

[0064] In combination Figure 6 As shown in FIG. 2, the first on-off valve 9 and the second on-off valve 10 are controlled to be opened, the solenoid valve 241 and the electronic expansion valve are controlled to be closed, so that the first refrigerant circulation loop is connected, and at the same time, the third on-off valve 11 and the fourth on-off valve 12 are controlled to be closed, so that the second refrigerant circulation loop is disconnected. In this way, the heat exchange branches can be in the series connection state.

[0065] In combination Figure 7 As shown in FIG. 3, the first on-off valve 9 and the second on-off valve 10 are controlled to be closed, so that the first refrigerant circulation loop is disconnected, and at the same time, the third on-off valve 11 and the fourth on-off valve 12 are controlled to be opened, the solenoid valve 241 and the electronic expansion valve are controlled to be turned on, so that the second refrigerant circulation loop is connected. In this way, the heat exchange branches can be in the parallel connection state.

[0066] The second pipeline 5 is provided with a throttling device 13. The throttling device 13 is located between the indoor heat exchanger 3 and the fourth position. By controlling the opening degree of the throttling device 13, the refrigerant flow between the outdoor heat exchanger 2 and the indoor heat exchanger 3 can be controlled. The throttling device 13 is open regardless of whether the heat exchange branches are in series or parallel, to ensure normal circulation of the refrigerant. Alternatively, the throttling device 13 is an expansion valve.

[0067] The air conditioner described above can be a single-cooling air conditioner or a cooling and heating air conditioner. When it is a cooling and heating air conditioner, the air conditioner further comprises a four-way valve.

[0068] In combination Figure 8 As shown in the drawings, the embodiment of the present disclosure provides a method for controlling oil return of an air conditioner compressor, comprising:

[0069] S801, the processor controls the compressor to operate at a higher frequency in response to a compressor oil return instruction.

[0070] S802, the processor compares the current state of each heat exchange branch with a preset state when the compressor is raised to a frequency threshold.

[0071] S803, the processor controls the on-off state of the first and second refrigerant circulation circuits when the current state is different from the preset state, so that the state of each heat exchange branch meets the preset state.

[0072] Generally, if the air conditioner is idle for a period of time, for example, idle for 12 hours, when the air conditioner is turned on again, the compressor will receive an oil return instruction. Alternatively, oil return is performed during air conditioner operation. The processor controls the compressor to operate at a higher frequency in response to the oil return instruction, so that the compressor returns oil. By obtaining the on-off state of the first on-off valve, the second on-off valve, the third on-off valve, the fourth on-off valve, the electromagnetic valve and the electronic expansion valve, it is determined whether the current state of each heat exchange branch is the same as the preset state. If not, the on-off state of the first and second refrigerant circulation circuits is switched to make the state of each heat exchange branch meet the preset state. If the same, the first and second refrigerant circulation circuits remain in the current on-off state. When each heat exchange branch is in the preset state, the condenser is in a higher temperature state, which is more conducive to oil return of the compressor.

[0073] In the embodiment of the present disclosure, during the oil return process of the compressor, it is judged whether the current state of each heat exchange branch is the same as the preset state. If not, the on-off state of the first and second refrigerant circulation circuits is controlled to make the state of each heat exchange branch meet the preset state. The preset state can make the condenser be in a higher temperature state, so that the compressor can quickly return oil. Reducing the impact on the normal operation of the air conditioner due to slow compressor oil return speed or long oil return time.

[0074] Optionally, when the frequency of the compressor rises to a frequency threshold f m , it is determined again whether the current state of each heat exchange branch is the same as the preset state. Optionally, the frequency threshold f m may be 85-88 Hz. When the frequency of the compressor rises to the frequency threshold, the compressor is in a high-frequency operation state. The compressor is also in a high-frequency operation state when it is performing oil return. Therefore, when the frequency of the compressor rises to the frequency threshold, it indicates that the compressor is performing oil return. At this time, it is determined whether the current state of each heat exchange branch is the same as the preset state, which can determine whether the current state of each heat exchange branch is conducive to the compressor quickly returning oil.

[0075] Optionally, the preset state is determined by the following method:

[0076] The processor controls the switching of the communication state of each heat exchange branch when the compressor is performing oil return.

[0077] The processor compares the temperature of the condenser before and after the switching of the communication state of each heat exchange branch.

[0078] The processor determines the communication state corresponding to the higher condenser temperature as the preset state.

[0079] When the compressor performs oil return for the first time, the communication state of each heat exchange branch is switched back and forth between the parallel connection communication state and the series connection communication state. Optionally, the switching is performed once or multiple times. The outlet of the condenser is provided with a first temperature sensor in communication connection with the processor, and the processor acquires the outlet temperature of the condenser through the first temperature sensor. When the switching is performed once, the outlet temperature of the condenser before the switching is recorded as T1, and the outlet temperature of the condenser after the switching is recorded as T2. The magnitudes of T1 and T2 are compared. If T1>T2, the communication state corresponding to the outlet temperature T1 is determined as the preset state. If T1<T2, the communication state corresponding to the outlet temperature T2 is determined as the preset state. When the switching is performed multiple times (n times), the outlet temperature of the condenser in each switching under one communication state is recorded as T 11 , T 12 , T 13 ……T 1n , and the outlet temperature of the condenser in each switching under another communication state is recorded as T 21 , T 22 , T 23 ……T 2n . The average values of the outlet temperatures under the two communication states are calculated as and The magnitudes of and are compared. If The outlet temperature is The corresponding connectivity state is determined as the preset state. The outlet temperature is The connection state corresponding to the condenser outlet temperature is determined as the preset state. Specifically, the connection state corresponding to a higher condenser outlet temperature is determined as the preset state. This is because refrigerant and oil are miscible, so where there is more refrigerant, there is also more oil. Refrigerant accounts for approximately 60% of the condenser's volume. If faster oil return is required, the refrigerant and oil must be mixed more quickly. This allows the oil and refrigerant to return to the compressor. The condenser outlet temperature reflects the system temperature. The higher the system temperature, the better the refrigerant and oil mix, resulting in faster oil return.

[0080] After determining the preset state, the processor stores the corresponding on / off states of the first and second refrigerant circulation circuits, namely, the on / off states of the first, second, third, and fourth on / off valves, the solenoid valve, and the electronic expansion valve. Subsequently, when the compressor returns to oil, it directly determines whether the current connectivity of each heat exchange branch meets the preset state. If not, the on / off states of the first and second refrigerant circulation circuits are switched so that the states of each heat exchange branch meet the preset state.

[0081] Optionally, combined Figure 9 As shown, the embodiment of the present disclosure provides another method for controlling oil return of an air-conditioning compressor, comprising:

[0082] S801: The processor controls the compressor to increase the frequency of operation in response to the compressor oil return instruction.

[0083] S802: When the frequency of the compressor reaches a frequency threshold, the processor compares the current state of each heat exchange branch with a preset state.

[0084] S813: When the current state is different from the preset state and the preset state is a parallel connection state, the processor controls the first refrigerant circulation loop to be disconnected and controls the second refrigerant circulation loop to be connected.

[0085] S823: When the current state is different from the preset state and the preset state is a serial connection state, the processor controls the first refrigerant circulation loop to be connected and controls the second refrigerant circulation loop to be disconnected.

[0086] As described above, the preset state is determined as the state corresponding to the higher condenser temperature, which can be the parallel connection state or the series connection state. In the case that the current state of each heat exchange branch is different from the preset state, the specific state of the preset state is determined. If the preset state is the parallel connection state, the first refrigerant circulation circuit is controlled to be disconnected and the second refrigerant circulation circuit is controlled to be connected. Specifically, the first on-off valve and the second on-off valve are controlled to be closed to disconnect the first refrigerant circulation circuit, and the third on-off valve and the fourth on-off valve are controlled to be opened, the solenoid valve and the electronic expansion valve are controlled to be turned on to connect the second refrigerant circulation circuit. In this way, each heat exchange branch can be in the parallel connection state. If the preset state is the series connection state, the first refrigerant circulation circuit is controlled to be connected and the second refrigerant circulation circuit is controlled to be disconnected. Specifically, the first on-off valve and the second on-off valve are controlled to be opened, the solenoid valve and the electronic expansion valve are controlled to be closed to connect the first refrigerant circulation circuit, and the third on-off valve and the fourth on-off valve are controlled to be closed to disconnect the second refrigerant circulation circuit. In this way, each heat exchange branch can be in the series connection state.

[0087] Optionally, in combination with Figure 10 As shown in the figure, the embodiment of the present disclosure provides another method for controlling oil return of an air conditioner compressor, comprising:

[0088] S801, the processor controls the compressor to operate at a higher frequency in response to a compressor oil return instruction.

[0089] S802, the processor compares the current state of each heat exchange branch with the preset state when the compressor is raised to a frequency threshold.

[0090] S803, the processor controls the on-off state of the first refrigerant circulation circuit and the second refrigerant circulation circuit in the case that the current state is different from the preset state, so that the state of each heat exchange branch meets the preset state.

[0091] S804, the processor acquires an ambient temperature.

[0092] S805, the processor adjusts the opening degree of the throttling device according to the ambient temperature.

[0093] The indoor environment is provided with a second temperature sensor in communication connection with the processor. After switching the communication state of each heat exchange branch to the preset state, the processor acquires the indoor environment temperature in real time through the second temperature sensor. The opening degree of the throttling device is adjusted based on the indoor environment temperature. Alternatively, the indoor environment temperature is positively correlated with the opening degree of the throttling device. The higher the indoor environment temperature, the greater the opening degree of the throttling device. This is because the greater the opening degree of the throttling device, the smaller the throttling effect on the refrigerant, and the higher the temperature of the refrigerant, the better the oil and refrigerant solubility, and then the oil return is fast. And the higher the indoor temperature, the greater the cooling / heating load of the air conditioner, which requires faster oil return to reduce the wear of the compressor. Therefore, adjusting the opening degree of the throttling device based on the environment temperature is conducive to matching the cooling / heating load for fast oil return.

[0094] Alternatively, S805, the processor adjusts the opening degree of the throttling device according to the environment temperature, comprising:

[0095] The processor determines the target opening degree of the throttling device corresponding to the current environment temperature according to the correlation between the environment temperature and the opening degree of the throttling device.

[0096] The processor controls the throttling device to open to the target opening degree.

[0097] The processor pre-stores the correlation between the environment temperature and the opening degree of the throttling device. The correlation includes one or more corresponding relationships between the environment temperature and the opening degree of the throttling device. The opening degree of the throttling device is represented as a percentage of the maximum opening A. When the indoor environment temperature is in a first temperature interval, the throttling device has a first opening degree. When the indoor environment temperature is in a second temperature interval, the throttling device has a second opening degree. When the indoor environment temperature is in a third temperature interval, the throttling device has a third opening degree. When the indoor environment temperature is in a fourth temperature interval, the throttling device has a fourth opening degree. When the indoor environment temperature is in a fifth temperature interval, the throttling device has a fifth opening degree. The first temperature interval, the second temperature interval, the third temperature interval, the fourth temperature interval and the fifth temperature interval decrease in turn. The first opening degree, the second opening degree, the third opening degree, the fourth opening degree and the fifth opening degree decrease in turn. Based on the corresponding relationship between the temperature interval in which the indoor environment temperature is located and the opening degree of the throttling device, the target opening degree corresponding to the current indoor environment temperature is determined. Specifically, the correlation between the environment temperature and the opening degree of the throttling device is shown in Table 1.

[0098] Table 1 Correlation between environment temperature and opening degree of throttling device

[0099]

[0100]

[0101] For example, if the indoor ambient temperature is 36℃, the target throttling device is determined to be 60% A, and the processor controls the opening of the throttling device to 60% A.

[0102] In this way, the temperature is divided to form multiple temperature intervals. Each temperature interval corresponds to a different opening degree, so that the target opening degree is adapted to the ambient temperature to achieve rapid oil return. Moreover, the switching of the shunt form of the throttling heat exchanger is matched with the control of the opening degree of the throttling device, which can better achieve rapid oil return.

[0103] Optionally, in combination with Figure 11 As shown in the drawings, the embodiment of the present disclosure provides another method for controlling oil return of an air conditioner compressor, comprising:

[0104] S801, the processor controls the compressor to operate at a frequency in response to a compressor oil return instruction.

[0105] S802, the processor compares the current state of each heat exchange branch with the preset state when the compressor is raised to a frequency threshold.

[0106] S803, the processor controls the on-off state of the first and second refrigerant circulation loops when the current state is different from the preset state, so that the state of each heat exchange branch meets the preset state.

[0107] S804, the processor acquires an ambient temperature.

[0108] S805, the processor adjusts the opening degree of the throttling device according to the ambient temperature.

[0109] S806, the processor acquires the operating parameters of the air conditioner when the compressor completes oil return.

[0110] S807, the processor determines the target state of each heat exchange branch according to the operating parameters of the air conditioner.

[0111] S808, the processor controls the on-off state of the first and second refrigerant circulation loops according to the target state, so that the state of each heat exchange branch meets the target state.

[0112] Generally, the compressor oil return demand can be met after the compressor runs for a period of time, for example, 3-4 minutes. At this time, it is determined that the compressor oil return is completed. Then, the operating parameters of the air conditioner are obtained, and the target state of each heat exchange branch is determined according to the operating parameters. Here, the operating parameters of the air conditioner include the temperature difference ΔT between the exhaust temperature T3 and the condenser outlet temperature T4. The worse the external environment, the greater the air conditioner load, and the less the heat exchange. This will result in a smaller temperature difference between the exhaust temperature and the condenser outlet temperature. Conversely, it is greater. Therefore, the temperature difference ΔT can reflect the operating load of the air conditioner. When the temperature difference ΔT is less than the temperature difference threshold ΔT', it indicates that the air conditioner operating load is large, and at this time the target state of each heat exchange branch is determined to be parallel-serial-parallel state. When the temperature difference ΔT is greater than or equal to the temperature difference threshold ΔT', it indicates that the air conditioner operating load is small, and at this time the target state of each heat exchange branch is determined to be serial-parallel-serial state. This is because when the air conditioner operating load is large, each heat exchange branch is in parallel-serial-parallel state, that is, the throttling heat exchanger is multi-branch, which can reduce the pressure loss and improve the output capacity of the air conditioner.

[0113] According to the target state, the on-off state of the first refrigerant circulation loop and the second refrigerant circulation loop is controlled to make the state of each heat exchange branch meet the target state. Specifically, if the air conditioner operating load is large and the current state is serial-parallel-serial state, each heat exchange branch is changed to parallel-serial-parallel state. If the current state is parallel-serial-parallel state, each heat exchange branch remains in parallel-serial-parallel state. If the air conditioner operating load is small and the current state is parallel-serial-parallel state, each heat exchange branch is changed to serial-parallel-serial state. If the current state is serial-parallel-serial state, each heat exchange branch remains in serial-parallel-serial state.

[0114] In actual application, as shown in FIG. 6, Figure 12

[0115] S1201, the air conditioner is started, and the processor controls the compressor to return oil in response to the compressor oil return instruction.

[0116] S1202, the processor controls the communication state of each heat exchange branch to switch between parallel-serial-parallel state and serial-parallel-serial state.

[0117] S1203, the processor obtains the outlet temperature T1 of the condenser in the parallel-serial-parallel state and the outlet temperature T2 in the serial-parallel-serial state.

[0118] S1204, the processor determines the size of T1 and T2; if T1>T2, S1205 is executed; if T1<T2, S1206 is executed.

[0119] S1205, the processor determines that the parallel-serial-parallel state is the preset state.

[0120] ​S1206, the processor determines that the series connection state is a preset state.

[0121] S1207, the processor controls the compressor to operate at a higher frequency.

[0122] S1208, the processor determines whether the operating frequency of the compressor has increased to f m ; if yes, S1209 is executed; if no, S1207 is executed.

[0123] S1209, the processor determines the difference between the current state and the preset state of the heat exchange branch; if the current state is different from the preset state and the preset state is the parallel connection state, S1210 is executed; if the current state is the same as the preset state, S1211 is executed; if the current state is different from the preset state and the preset state is the series connection state, S1212 is executed.

[0124] S1210, the processor controls the first refrigerant circulation loop to be disconnected and controls the second refrigerant circulation loop to be connected; then S1213 is executed.

[0125] S1211, the processor controls the first refrigerant circulation loop and the second refrigerant circulation loop to maintain the current on-off state; then S1213 is executed.

[0126] S1212, the processor controls the first refrigerant circulation loop to be connected and controls the second refrigerant circulation loop to be disconnected; then S1213 is executed.

[0127] S1213, the processor acquires the indoor environment temperature.

[0128] S1214, the processor adjusts the opening degree of the throttling device according to the indoor environment temperature; after 2-3 minutes, S1215 is executed.

[0129] S1215, the processor completes oil return of the compressor.

[0130] S1216, the processor acquires the exhaust temperature T3 and the condenser outlet temperature T4, and calculates the temperature difference ΔT = T3-T4.

[0131] S1217, the processor determines whether ΔT < ΔT' is satisfied; if yes, S1218 is executed; if no, S1219 is executed.

[0132] S1218, the processor determines that the parallel connection state is the target state; then S1220 is executed.

[0133] S1219, the processor determines that the series connection state is the target state; then S1220 is executed.

[0134] S1220, the processor judges the difference between the current state and the target state of the heat exchange branch; if the current state is different from the target state, and the target state is the parallel connection communication state, S1221 is executed; if the current state is the same as the target state, S1222 is executed; if the current state is different from the target state, and the target state is the series connection communication state, S1223 is executed.

[0135] S1221, the processor controls the first refrigerant circulation loop to be disconnected, and controls the second refrigerant circulation loop to be connected.

[0136] S1222, the processor controls the first refrigerant circulation loop and the second refrigerant circulation loop to keep the current on-off state.

[0137] S1223, the processor controls the first refrigerant circulation loop to be connected, and controls the second refrigerant circulation loop to be disconnected.

[0138] It should be noted that if the compressor performs oil return for the first time, the processor executes S1201-S1223, and the preset state is stored in the processor. If the compressor performs oil return for the second time, the processor retrieves the previously stored preset state, and directly executes S1207-S1223. Of course, the processor can execute S1201-S1223 every time the compressor performs oil return.

[0139] In combination Figure 13 As shown in the figure, the embodiment of the present disclosure provides a device for controlling air conditioner compressor oil return, which comprises a first control module 131, a comparison module 132 and a second control module 133. The first control module 131 is configured to control the compressor to operate at a high frequency in response to a compressor oil return instruction. The comparison module 132 is configured to compare the current state of each heat exchange branch with the preset state. The second control module 133 is configured to control the on-off state of the first refrigerant circulation loop and the second refrigerant circulation loop in the case that the current state is different from the preset state, so that the state of each heat exchange branch meets the preset state.

[0140] The device for controlling air conditioner compressor oil return provided by the embodiment of the present disclosure is adopted, in the process of compressor oil return, whether the current state of each heat exchange branch is the same as the preset state is judged. If not, the on-off state of the first refrigerant circulation loop and the second refrigerant circulation loop is controlled, so that the state of each heat exchange branch meets the preset state. The preset state can make the condenser be in a higher temperature state, so as to make the compressor quickly return oil. The influence on the normal operation of the air conditioner caused by slow compressor oil return speed or too long oil return time is reduced.

[0141] In combination Figure 14As shown, the embodiment of the present disclosure provides a device for controlling oil return of an air conditioner compressor, which comprises a processor 140 and a memory 141. Optionally, the device can further comprise a communication interface 142 and a bus 143. The processor 140, the communication interface 142 and the memory 141 can communicate with each other through the bus 143. The communication interface 142 can be used for information transmission. The processor 140 can invoke the logical instructions in the memory 141 to execute the method for controlling oil return of an air conditioner compressor in the above embodiment.

[0142] In addition, the logical instructions in the memory 141 described above can be realized in the form of a software functional unit and sold or used as an independent product, which can be stored in a computer readable storage medium.

[0143] The memory 141 as a computer readable storage medium can be used to store software programs, computer executable programs, such as program instructions / modules corresponding to the method in the embodiment of the present disclosure. The processor 140 executes the program instructions / modules stored in the memory 141, thereby performing functional applications and data processing, i.e. realizing the method for controlling oil return of an air conditioner compressor in the above embodiment.

[0144] The memory 141 can include a program storage area and a data storage area, wherein the program storage area can store an operating system and application programs required by at least one function; the data storage area can store data created according to the use of the terminal device, etc. In addition, the memory 141 can include a high-speed random access memory, and can further include a non-volatile memory.

[0145] The embodiment of the present disclosure provides an air conditioner comprising the device for controlling oil return of an air conditioner compressor described above.

[0146] The embodiment of the present disclosure provides a storage medium, which stores computer executable instructions, and the computer executable instructions are configured to execute the method for controlling oil return of an air conditioner compressor described above.

[0147] The storage medium described above can be a transitory computer readable storage medium or a non-transitory computer readable storage medium.

[0148] The above description and the accompanying drawings fully illustrate the embodiments of the present disclosure so that those skilled in the art can practice them. Other embodiments may include structural, logical, electrical, process and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the words used in this application are only used to describe the embodiments and are not used to limit the claims. As used in the description of the embodiments and claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to also include plural forms. Similarly, the term "and / or" as used in this application refers to any and all possible combinations of one or more associated listings. In addition, when used in this application, the term "comprise" and its variations "comprises" and / or comprising refer to the presence of stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups of these. In the absence of further restrictions, an element defined by the sentence "comprising a..." does not exclude the presence of other identical elements in the process, method or device that includes the element. In this article, each embodiment may focus on the differences from other embodiments, and the same and similar parts between the various embodiments can be referenced to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method part disclosed in the embodiments, then the relevant parts can be found in the description of the method part.

[0149] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software may depend on the specific application and design constraints of the technical solution. The technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the embodiments of the present disclosure. The technicians will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0150] In the embodiments disclosed herein, the disclosed methods, products (including but not limited to apparatuses, devices, etc.) can be implemented in other manners. For example, the described apparatus embodiments are merely schematic. For example, the division of the units is merely a logical function division. There can be another division manner for the actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between different units, or among them, can be indirect couplings or communication connections through some interfaces, devices, or units, and can be in electric, mechanical, or other forms.

[0151] The flowcharts and block diagrams in the drawings show the possible implementation architectures, functions, and operations of the system, method, and computer program product according to the embodiments of the present disclosure. In this regard, each block in the flowcharts or block diagrams can represent a module, a program segment, or a part of code, which contains one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions noted in the blocks can occur in an order different from that noted in the drawings. For example, two consecutive blocks can actually be executed substantially in parallel, and sometimes they can be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the drawings, the operations or steps corresponding to different blocks can also occur in an order different from that disclosed in the descriptions, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and sometimes they can be executed in reverse order, depending on the functions involved. Each block in the block diagrams and / or flowcharts, and the combination of blocks in the block diagrams and / or flowcharts, can be implemented by a dedicated hardware-based system that performs the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A method for controlling oil return of an air conditioning compressor, the air conditioning comprising: Throttling heat exchanger The throttling heat exchanger comprises a plurality of heat exchange branches; characterized in that the air conditioner further comprises a first refrigerant circulation loop and a second refrigerant circulation loop sharing the throttling heat exchanger; by switching the on-off state of the first refrigerant circulation loop and the second refrigerant circulation loop, each heat exchange branch can be switched between parallel connection and series connection; the method comprises: In response to the compressor oil return instruction, the compressor is controlled to operate at a higher frequency; Compare the current state of each heat exchange branch with the preset state; wherein the preset state is determined by the following method, including: in the case of compressor oil return, the connection state of each heat exchange branch is controlled to switch; compare the temperature of the condenser before and after the connection state of each heat exchange branch is switched; the connection state corresponding to the higher condenser temperature is determined as the preset state; In the case where the current state is different from the preset state, the on-off state of the first refrigerant circulation loop and the second refrigerant circulation loop is controlled to make the state of each heat exchange branch meet the preset state.

2. The method of claim 1, wherein, The connection state corresponding to the higher condenser temperature is determined as the preset state, comprising: When the connection state of each heat exchange branch is switched once, record the outlet temperature of the condenser before switching as T1 and the outlet temperature of the condenser after switching as T2; If T1>T2, the connection state corresponding to the outlet temperature T1 is determined as the preset state; If T1<T2, the connection state corresponding to the outlet temperature T2 is determined as the preset state.

3. The method of claim 1, wherein, The connection state corresponding to the higher condenser temperature is determined as the preset state, comprising: When the connection state of each heat exchange branch is switched multiple times, record the outlet temperature of the condenser in one connection state and the outlet temperature of the condenser in another connection state; Calculate the average value of the outlet temperature in the two connected states respectively and If the corresponding communication state of the export temperature is determined as the preset state; If the communication state corresponding to the export temperature of is determined as the preset state.

4. The method of claim 1, wherein, The preset state is parallel connection; the control of the on-off state of the first refrigerant circulation loop and the second refrigerant circulation loop comprises: The first refrigerant circulation loop is controlled to be disconnected; and The second refrigerant circulation loop is controlled to be connected.

5. The method of claim 1, wherein, The preset state is series connection; the control of the on-off state of the first refrigerant circulation loop and the second refrigerant circulation loop comprises: The first refrigerant circulation loop is controlled to be connected; and The second refrigerant circulation loop is controlled to be disconnected.

6. The method of claim 1, wherein, After the control of the on-off state of the first refrigerant circulation loop and the second refrigerant circulation loop, the method further comprises: Obtain the indoor environment temperature; According to the indoor environment temperature, adjust the opening degree of the throttling device.

7. The method of claim 6, wherein, According to the indoor environment temperature, adjust the opening degree of the throttling device, comprising: According to the correlation between the indoor environment temperature and the opening degree of the throttling device, determine the target opening degree of the throttling device corresponding to the current indoor environment temperature; Control the throttling device to open to the target opening degree.

8. The method of claim 7, wherein, After the opening degree of the throttling device is adjusted according to the indoor environment temperature, the method further comprises: In the case where the compressor completes oil return, obtain the operating parameters of the air conditioner; According to the operating parameters of the air conditioner, determine the target state of each heat exchange branch; According to the target state, the on-off state of the first refrigerant circulation loop and the second refrigerant circulation loop is controlled to make the state of each heat exchange branch meet the target state.

9. The method of claim 8, wherein, The operation parameters of the air conditioner include: a temperature difference between the discharge temperature and the condenser outlet temperature; and the target state of each heat exchange branch is determined according to the operation parameters of the air conditioner, including: In the case that the temperature difference between the discharge temperature and the condenser outlet temperature is less than a temperature difference threshold, the target state of each heat exchange branch is determined as the parallel-serial-parallel communication state; In the case that the temperature difference between the discharge temperature and the condenser outlet temperature is greater than or equal to the temperature difference threshold, the target state of each heat exchange branch is determined as the serial-parallel-serial communication state.

10. An apparatus for controlling oil return of an air conditioning compressor, comprising a processor and a memory having stored program instructions, characterized in that, The processor is configured to execute the method for controlling oil return of an air conditioner compressor when the program instructions are executed.

11. An air conditioner comprising: Throttling heat exchanger; The throttling heat exchanger includes a plurality of heat exchange branches; and the air conditioner further includes: A first refrigerant circulation loop and a second refrigerant circulation loop sharing the throttling heat exchanger; by switching the on-off state of the first refrigerant circulation loop and the second refrigerant circulation loop, each heat exchange branch can be switched between the parallel-serial-parallel communication state and the serial-parallel-serial communication state; and The device for controlling oil return of an air conditioner compressor according to claim 10.

12. A storage medium storing program instructions, characterized in that, The program instructions execute the method for controlling oil return of an air conditioner compressor when executed.

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