Air conditioner and control method therefor, and computer-readable storage medium

Abstract

Provided in the present disclosure are an air conditioner and a control method therefor, and a computer-readable storage medium. The air conditioner comprises a compressor, a reversing apparatus, an outdoor heat exchanger, an electronic expansion valve, a coolant ring, a variable-flow throttling valve and an indoor heat exchanger, which are sequentially connected, wherein the variable-flow throttling valve is configured to automatically adjust the coolant flow when the air conditioner runs in a cooling mode, so as to be adapted to a load change; and the electronic expansion valve is configured to perform opening-degree increase adjustment when the air conditioner runs in a non-reversing defrosting mode, and the opening degree stagewise changes.

Description

Air conditioner, control method thereof, and computer readable storage medium

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application No. 202410149838.0, filed on February 1, 2024, entitled “AIR CONDITIONER, CONTROL METHOD THEREOF, AND COMPUTER-READABLE STORAGE MEDIUM,” and claims priority to Chinese patent application No. 202420259478.5, filed on February 1, 2024, entitled “AIR CONDITIONER,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the technical field of air conditioners, and in particular to an air conditioner, a control method for an air conditioner, and a computer-readable storage medium. Background Art

[0004] Currently, when the air conditioner is running in heating mode in winter, the temperature of the outdoor heat exchanger continues to absorb heat from the environment and will be maintained at a lower temperature. When the outdoor ambient temperature is low, the temperature of the heat exchanger may be lower than 0 degrees Celsius. At this time, the heat exchanger will gradually frost. When the frost layer accumulates to a certain thickness, it will seriously affect the heating effect of the air conditioner. Therefore, the air conditioner needs to be defrosted frequently.

[0005] At present, the relevant technology mainly adopts reverse defrosting when performing defrosting, that is, it is necessary to switch to cooling mode for defrosting during the heating process. During this period, the air conditioner stops supplying heat, and the indoor temperature will fluctuate greatly. At the same time, when the four-way valve is cut, a "click" sound will be generated, which reduces the user's heating experience. In addition, the existing electronic valve flow path cannot take into account the needs of normal system operation and reversing defrosting, and the throttling element (such as a capillary tube) cannot take into account the needs of different flow rates under high and low loads of the system. In addition, there is a method in the prior art to throttle by setting an electronic expansion valve in the refrigerant flow path instead of the capillary tube. Although it can take into account the needs of different flow rates under high and low loads of the system when the air conditioner is in cooling operation, this method increases the system cost. In addition, the existing electronic expansion valve usually has a fixed lower limit opening to avoid the problem of condensation water when the refrigerant after excessive throttling flows through the refrigerant ring, which leads to the problem of electronic control short circuit. Environmental factors are not taken into account, and there is a risk of electronic control short circuit or even burning.

[0006] Public content

[0007] The present disclosure aims to solve, at least to a certain extent, one of the technical problems in the related art. To this end, the first object of the present disclosure is to provide an air conditioner, wherein a variable flow throttle valve is configured to automatically adjust the refrigerant flow rate to adapt to load changes when the air conditioner is in cooling operation; and an electronic expansion valve is configured to increase its opening when the air conditioner is in non-reversing defrosting operation, and the opening changes in a staged manner, thereby achieving non-reversing defrosting at low cost and reducing the risk of short circuit and burning of the electronic control. The heating effect of the air conditioner can be ensured when the refrigerant flow rate is low, and the throttling effect can be ensured when the air conditioner is under low load, the reliability of the compressor oil return is guaranteed, and sufficient flow is ensured when the air conditioner is under high load, thereby ensuring the cooling effect of the air conditioner.

[0008] A second objective of the present disclosure is to provide a method for controlling an air conditioner.

[0009] A third object of the present disclosure is to provide a computer-readable storage medium.

[0010] To achieve the above-mentioned objectives, the first aspect embodiment of the present disclosure proposes an air conditioner, comprising: a compressor, a reversing device, an outdoor heat exchanger, an electronic expansion valve, a refrigerant ring, a variable flow throttle valve and an indoor heat exchanger connected in sequence, wherein the variable flow throttle valve is configured to automatically adjust the refrigerant flow rate when the air conditioner is in cooling operation to adapt to load changes; the electronic expansion valve is configured to increase the opening degree when the air conditioner is not in reversing defrosting operation, and the opening degree changes in stages.

[0011] According to the air conditioner of the disclosed embodiment, the variable flow throttle valve is configured to automatically adjust the refrigerant flow rate to accommodate load changes during cooling operation. The electronic expansion valve is configured to open wider and in stages during non-reversing defrosting operation. This allows the air conditioner to achieve non-reversing defrosting at low cost, while reducing the risk of short-circuiting and burning the electronic control. This ensures heating performance at low refrigerant flow rates, throttling performance at low loads, and reliable oil return from the compressor. Furthermore, it ensures sufficient flow and cooling performance at high loads.

[0012] In addition, the air conditioner according to the above embodiment of the present disclosure may also have the following additional technical features:

[0013] According to one embodiment of the present disclosure, the air conditioner further includes: a controller, which is configured to determine the lower limit opening of the electronic expansion valve according to the outdoor ambient temperature when the air conditioner is in cooling operation, and to limit the opening of the electronic expansion valve according to the lower limit opening.

[0014] According to one embodiment of the present disclosure, the controller is further configured to, when the outdoor ambient temperature is less than or equal to a first preset outdoor temperature, set the first opening value to the lower limit opening; when the outdoor ambient temperature is greater than the first preset outdoor temperature and less than or equal to a second preset outdoor temperature, determine the lower limit opening according to a preset linear relationship; when the outdoor ambient temperature is greater than the second preset outdoor temperature, set the second opening value to the lower limit opening; wherein, the preset linear relationship is a linear function with the outdoor ambient temperature as a variable, the first opening value is less than the minimum value of the preset linear relationship, and the maximum value of the preset linear relationship is less than the second opening value.

[0015] According to one embodiment of the present disclosure, the controller is further configured to, when the air conditioner is not operating in a reverse defrosting mode, obtain the current opening of the electronic expansion valve, and adjust the opening of the electronic expansion valve multiple times based on the current opening, so that the opening of the electronic expansion valve changes in stages.

[0016] According to one embodiment of the present disclosure, the controller is further configured to determine the target opening and the number of opening adjustments of the electronic expansion valve, determine the adjustment step according to the current opening, the target opening and the number of opening adjustments, and perform multiple increasing adjustments to the opening of the electronic expansion valve according to the adjustment step.

[0017] According to one embodiment of the present disclosure, the air conditioner further includes: a controller, which is further configured to obtain at least one of the indoor ambient temperature, the outdoor ambient temperature and the outdoor heat exchanger temperature, and determine that the air conditioner does not reverse to defrost operation based on at least one of the indoor ambient temperature, the outdoor ambient temperature and the outdoor heat exchanger temperature.

[0018] According to one embodiment of the present disclosure, the controller controls the air conditioner not to switch to defrost mode when it is determined that any of the following conditions are not met: (1) the indoor ambient temperature is lower than a first preset temperature, or the outdoor ambient temperature is lower than a second preset temperature, or the sum of the indoor ambient temperature and the outdoor ambient temperature is lower than a third preset temperature; (2) the change in the outdoor heat exchanger temperature is lower than a fourth preset temperature; (3) the outdoor ambient temperature is lower than a fifth preset temperature and the air conditioner does not enter the defrost mode within a second preset time, wherein the fifth preset temperature is higher than the second preset temperature.

[0019] According to one embodiment of the present disclosure, the controller is also configured to obtain a first temperature change value of the outdoor heat exchanger and a second temperature change value of the outdoor ambient temperature within a third preset time; and determine the change value of the outdoor heat exchanger temperature based on the relationship between the first temperature change value and the second temperature change value.

[0020] According to one embodiment of the present disclosure, the controller is further configured to, when the change value of the outdoor heat exchanger temperature is less than a sixth preset temperature, control the air conditioner to enter a first non-reversing defrost mode; when the change value of the outdoor heat exchanger temperature is less than a seventh preset temperature, control the air conditioner to enter a second non-reversing defrost mode; wherein the seventh preset temperature is less than the sixth preset temperature, and the sixth preset temperature is greater than the fourth preset temperature.

[0021] According to one embodiment of the present disclosure, the controller is further configured to, when the air conditioner is operating in the first non-reversing defrost mode, if no change in the opening of the electronic expansion valve is detected, control the air conditioner to exit the first non-reversing defrost mode if the outdoor heat exchanger temperature is greater than an eighth preset temperature or the operating time of the first non-reversing defrost mode is greater than a third preset time; if a change in the opening of the electronic expansion valve is detected, after a delay of a fourth preset time, determine whether to exit the first non-reversing defrost mode based on the outdoor heat exchanger temperature.

[0022] According to one embodiment of the present disclosure, the controller is further configured to, when the air conditioner is operating in the second non-reversing defrost mode, if no change in the opening of the electronic expansion valve is detected, control the air conditioner to exit the second non-reversing defrost mode when the outdoor heat exchanger temperature is greater than a ninth preset temperature or the operating time of the second non-reversing defrost mode is greater than a fifth preset time; if a change in the opening of the electronic expansion valve is detected, after a delay of a sixth preset time, determine whether the air conditioner exits the second non-reversing defrost mode based on the outdoor heat exchanger temperature; wherein the ninth preset temperature is greater than the eighth preset temperature, and the fifth preset time is greater than the third preset time.

[0023] According to one embodiment of the present disclosure, the controller is further configured to, when the air conditioner enters the first non-reversing defrost mode, control the compressor to operate at a first operating frequency, stop the outdoor fan, and keep the speed of the indoor fan unchanged; when the air conditioner enters the second non-reversing defrost mode, control the compressor to operate at a second operating frequency, stop the outdoor fan, and reduce the speed of the indoor fan at a preset rate; wherein, the first operating frequency is less than the second operating frequency.

[0024] According to one embodiment of the present disclosure, the electronic expansion valve is a wide-range variable gain electronic expansion valve.

[0025] According to an embodiment of the present disclosure, the wide-range variable gain electronic expansion valve is further configured to change its opening degree based on the load change when the air conditioner is in heating operation.

[0026] According to one embodiment of the present disclosure, the wide-range variable gain electronic expansion valve includes a valve body, an inlet and an outlet are provided on the valve body, a valve seat is provided at the outlet, a valve needle is provided on the valve seat, a gap between the valve needle and the valve seat forms a throttling hole, and the valve needle adjustment section is designed with multiple angles.

[0027] According to one embodiment of the present disclosure, the caliber of the valve seat ranges from 1.6 mm to 3.2 mm.

[0028] According to one embodiment of the present disclosure, the variable flow throttle valve includes: a shell, a mounting channel is formed in the shell, the shell has a first medium flow port and a second medium flow port, the mounting channel connects the first medium flow port and the second medium flow port; a first valve seat, the first valve seat is installed in the mounting channel, the first valve seat is formed with an adjacent first hole and a first medium flow channel, the first medium flow channel connects the first medium flow port and the first hole, and the first hole is suitable for connecting the first medium flow channel and the second medium flow port; the first valve seat is also formed with an adjacent second hole and a second medium flow channel, the second medium flow channel connects the second medium flow port and the second hole, and the second hole is suitable for connecting the first medium flow port and the second medium flow channel; a first valve core, the first valve core is arranged in the first medium flow channel, and the first valve core is movable along the first medium flow channel to open or close the first hole; the second valve core, the second valve core is arranged in the second medium flow channel, and the second valve core is movable along the second medium flow channel to open or close the second hole.

[0029] According to one embodiment of the present disclosure, when the medium flows into the installation channel through the first medium flow port, the medium drives the first valve core to move to close the first hole and drives the second valve core to move to open the second hole; when the medium flows into the installation channel through the second medium flow port, the medium drives the first valve core to move to open the first hole and drives the second valve core to move to close the second hole; wherein, along the length direction of the installation channel, the first hole and the second hole are located between the first medium flow channel and the second medium flow channel.

[0030] According to one embodiment of the present disclosure, a throttling channel and a conducting channel are further formed in the shell, the throttling channel connects the first medium flow port and the second hole, and the conducting channel connects the second medium flow port and the first hole, wherein the throttling channel and / or the conducting channel are formed on the first valve seat.

[0031] According to one embodiment of the present disclosure, a first communicating flow channel is formed between the first valve seat and the outer shell, and the first communicating flow channel connects the throttling channel and the first medium flow port; a second communicating flow channel is formed between the first valve seat and the outer shell, and the second communicating flow channel connects the conducting channel and the second medium flow port.

[0032] According to one embodiment of the present disclosure, a first limiter is provided in the first medium flow channel, the first limiter is located on the side of the first valve core away from the first hole, the first limiter forms a third connecting flow channel connecting the first medium flow channel and the first medium flow port, and the first limiter is suitable for cooperating with the first valve core in a limiting manner; a second limiter is provided in the second medium flow channel, the second limiter is located on the side of the second valve core away from the second hole, the second limiter forms a fourth connecting flow channel connecting the second medium flow channel and the second medium flow port, and the second limiter is suitable for cooperating with the second valve core in a limiting manner.

[0033] According to one embodiment of the present disclosure, the variable flow throttle valve further includes: an elastic member, which is assembled in the second medium flow channel and located between the second valve core and the second limit member, and the elastic member is connected between the second valve core and the second limit member.

[0034] According to one embodiment of the present disclosure, the second valve core includes: a valve core body and a closing column connected to each other, and the closing column is used to open or close the second hole.

[0035] According to one embodiment of the present disclosure, the valve core body is constructed in a cylindrical shape, or at least one notch is formed on the side wall of the valve core body.

[0036] According to one embodiment of the present disclosure, the variable flow throttle valve further includes: a first filter element, which is installed in the installation channel and located between the first valve seat and the first medium flow port; and a second filter element, which is installed in the installation channel and located between the first valve seat and the second medium flow port.

[0037] To achieve the above-mentioned purpose, the second aspect embodiment of the present disclosure proposes a control method for an air conditioner, wherein the air conditioner includes: a compressor, a reversing device, an outdoor heat exchanger, an electronic expansion valve, a refrigerant ring, a variable flow throttle valve and an indoor heat exchanger connected in sequence, and the method includes: determining the operating conditions of the air conditioner; when the air conditioner is in cooling operation, automatically adjusting the refrigerant flow based on the variable flow throttle valve to adapt to load changes; when the air conditioner is in non-reversing defrosting operation, adjusting the opening of the electronic expansion valve to increase, and the opening changes in stages.

[0038] According to the control method for an air conditioner according to the embodiment of the present disclosure, the operating condition of the air conditioner is determined. When the air conditioner is in cooling operation, the refrigerant flow rate is automatically adjusted based on the variable flow throttle valve to adapt to load changes. When the air conditioner is in non-reversing defrosting operation, the opening of the electronic expansion valve is adjusted to increase, and the opening rate changes in stages. As a result, this method can achieve non-reversing defrosting at low cost and reduce the risk of short circuit and burnout of the electronic control. It can ensure the heating effect of the air conditioner when the refrigerant flow rate is low, ensure the throttling effect when the air conditioner is under low load, ensure the reliability of the compressor oil return, and ensure sufficient flow rate and cooling effect when the air conditioner is under high load.

[0039] In addition, the air conditioner according to the above embodiment of the present disclosure may also have the following additional technical features:

[0040] According to one embodiment of the present disclosure, the lower limit opening of the electronic expansion valve is determined according to the outdoor ambient temperature, including: when the outdoor ambient temperature is less than or equal to a first preset outdoor temperature, setting the first opening value to the lower limit opening; when the outdoor ambient temperature is greater than the first preset outdoor temperature and less than or equal to a second preset outdoor temperature, determining the lower limit opening according to a preset linear relationship; when the outdoor ambient temperature is greater than the second preset outdoor temperature, setting the second opening value to the lower limit opening; wherein the preset linear relationship is a linear function with the outdoor ambient temperature as a variable, the first opening value is less than the minimum value of the preset linear relationship, and the maximum value of the preset linear relationship is less than the second opening value.

[0041] According to one embodiment of the present disclosure, the opening of the electronic expansion valve is adjusted to be larger, and the opening changes in stages, including: obtaining the current opening of the electronic expansion valve, and adjusting the opening of the electronic expansion valve to be larger multiple times according to the current opening, so that the opening of the electronic expansion valve changes in stages.

[0042] According to one embodiment of the present disclosure, the opening of the electronic expansion valve is adjusted to be larger multiple times according to the current opening, including: determining the target opening and the number of opening adjustments of the electronic expansion valve, and determining an adjustment step according to the current opening, the target opening and the number of opening adjustments, and adjusting the opening of the electronic expansion valve to be larger multiple times according to the adjustment step.

[0043] According to one embodiment of the present disclosure, the control method of the air conditioner also includes: obtaining at least one of the indoor ambient temperature, the outdoor ambient temperature and the outdoor heat exchanger temperature, and determining that the air conditioner is not reversing to defrost operation based on at least one of the indoor ambient temperature, the outdoor ambient temperature and the outdoor heat exchanger temperature.

[0044] According to one embodiment of the present disclosure, when it is determined that any of the following conditions is not met, the air conditioner is controlled not to switch to defrost operation: (1) the indoor ambient temperature is lower than a first preset temperature, or the outdoor ambient temperature is lower than a second preset temperature, or the sum of the indoor ambient temperature and the outdoor ambient temperature is lower than a third preset temperature; (2) the change value of the outdoor heat exchanger temperature is lower than a fourth preset temperature; (3) the outdoor ambient temperature is lower than a fifth preset temperature and the air conditioner does not enter the defrost mode within a second preset time, wherein the fifth preset temperature is higher than the second preset temperature.

[0045] According to one embodiment of the present disclosure, the control method of the air conditioner also includes: obtaining a first temperature change value of the outdoor heat exchanger and a second temperature change value of the outdoor ambient temperature within a third preset time; and determining the change value of the outdoor heat exchanger temperature based on the relationship between the first temperature change value and the second temperature change value.

[0046] According to one embodiment of the present disclosure, the control method of the air conditioner also includes: when the change value of the outdoor heat exchanger temperature is less than the sixth preset temperature, controlling the air conditioner to enter a first non-reversing defrost mode; when the change value of the outdoor heat exchanger temperature is less than the seventh preset temperature, controlling the air conditioner to enter a second non-reversing defrost mode; wherein the seventh preset temperature is less than the sixth preset temperature, and the sixth preset temperature is greater than the fourth preset temperature.

[0047] According to one embodiment of the present disclosure, when the air conditioner is operating in the first non-reversing defrost mode, the method further includes: if no change in the opening of the electronic expansion valve is detected, then when the outdoor heat exchanger temperature is greater than an eighth preset temperature or the operating time of the first non-reversing defrost mode is greater than a third preset time, controlling the air conditioner to exit the first non-reversing defrost mode; if a change in the opening of the electronic expansion valve is detected, then after a delay of a fourth preset time, determining whether the air conditioner exits the first non-reversing defrost mode based on the outdoor heat exchanger temperature.

[0048] According to one embodiment of the present disclosure, when the air conditioner is operating in the second non-reversing defrost mode, the method further includes: if no change in the opening of the electronic expansion valve is detected, then when the outdoor heat exchanger temperature is greater than a ninth preset temperature or the operating time of the second non-reversing defrost mode is greater than a fifth preset time, controlling the air conditioner to exit the second non-reversing defrost mode; if a change in the opening of the electronic expansion valve is detected, then after a delay of a sixth preset time, determining whether the air conditioner exits the second non-reversing defrost mode based on the outdoor heat exchanger temperature; wherein the ninth preset temperature is greater than the eighth preset temperature, and the fifth preset time is greater than the third preset time.

[0049] According to one embodiment of the present disclosure, the control method of the air conditioner also includes: when the air conditioner enters the first non-reversing defrost mode, controlling the compressor to operate at a first operating frequency, the outdoor fan to stop, and the speed of the indoor fan to remain unchanged; when the air conditioner enters the second non-reversing defrost mode, controlling the compressor to operate at a second operating frequency, the outdoor fan to stop, and the speed of the indoor fan to decrease according to a preset rate; wherein, the first operating frequency is less than the second operating frequency.

[0050] To achieve the above-mentioned objectives, a third embodiment of the present disclosure proposes a computer-readable storage medium having a computer program stored thereon, which implements the above-mentioned air conditioner control method when executed by a processor.

[0051] According to the computer-readable storage medium of the embodiment of the present disclosure, by implementing the above-mentioned air conditioner control method during execution, non-reversing defrosting can be achieved at low cost, and the risk of short circuit and burning of the electronic control can be reduced. The heating effect of the air conditioner can be ensured when the refrigerant flow is low, and the throttling effect can be ensured when the air conditioner is under low load, the reliability of the compressor oil return can be guaranteed, and sufficient flow can be ensured when the air conditioner is under high load, thereby ensuring the cooling effect of the air conditioner.

[0052] Additional aspects and advantages of the present disclosure will be given in part in the description below and in part will be obvious from the description below, or will be learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The above and / or additional aspects and advantages of the present disclosure will become apparent and readily understood from the description of the embodiments with reference to the following drawings, in which:

[0054] FIG1 is a system diagram of an air conditioner according to one embodiment of the present disclosure;

[0055] FIG2 is a block diagram of an air conditioner in the prior art;

[0056] FIG3 is a block diagram of an air conditioner in the prior art;

[0057] FIG4 is a schematic diagram of a variable flow throttle valve according to an embodiment of the present disclosure;

[0058] FIG5 is a schematic diagram of an electronic expansion valve according to one embodiment of the present disclosure;

[0059] FIG6 is a schematic diagram of an electronic expansion valve according to another embodiment of the present disclosure;

[0060] FIG7 is a schematic structural diagram of a variable flow throttle valve according to an embodiment of the present disclosure;

[0061] FIG8 is a flow chart of a method for controlling an air conditioner according to an embodiment of the present disclosure;

[0062] FIG9 is a flowchart of a method for controlling an air conditioner according to a specific example of the present disclosure. DETAILED DESCRIPTION

[0063] The following describes in detail embodiments of the present disclosure, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present disclosure, and should not be construed as limiting the present disclosure.

[0064] As shown in FIG2 , currently, in an air conditioner system, an electronic expansion valve and a capillary tube are provided between the evaporator and the condenser. When the air conditioner is operating in cooling mode, the refrigerant passing through the evaporator can be throttled through the capillary tube. However, the throttling method through the capillary tube cannot take into account the different flow requirements of the system at high and low loads. In addition, as shown in FIG3 , in order to take into account the different flow requirements of the system at high and low loads, an electronic expansion valve is provided between the outdoor heat exchanger and the indoor heat exchanger. By adjusting the opening of the electronic expansion valve, the refrigerant flow in the refrigerant circuit can be adjusted. Although this method can take into account the different flow requirements of the system at high and low loads, it increases the system cost. Therefore, the present disclosure proposes an air conditioner that can reduce costs by providing a variable flow throttle valve and can automatically adjust the refrigerant flow to adapt to load changes.

[0065] The air conditioner, the control method of the air conditioner, and the computer-readable storage medium proposed in the embodiments of the present disclosure are described below with reference to the accompanying drawings.

[0066] FIG1 is a system diagram of an air conditioner according to one embodiment of the present disclosure.

[0067] As shown in FIG. 1 , the air conditioner 100 of the present disclosure may include a compressor 70 , a reversing device 60 , an outdoor heat exchanger 20 , an electronic expansion valve 40 , a refrigerant loop 50 , a variable flow throttle valve 30 , and an indoor heat exchanger 10 , which are sequentially connected.

[0068] The variable flow throttle valve 30 is configured to automatically adjust the refrigerant flow rate to accommodate load changes when the air conditioner 100 is in cooling mode. The electronic expansion valve 40 is configured to open wider and in stages when the air conditioner 100 is not in defrosting mode.

[0069] Specifically, as shown in FIG1 , the variable flow throttle valve 30 is positioned to the left of the refrigerant ring 50, and the electronic expansion valve 40 is positioned to the right of the refrigerant ring 50. This allows the refrigerant to first pass through the electronic expansion valve 40, then through the refrigerant ring 50, before flowing to the variable flow throttle valve 30 for throttling during the cooling process of the air conditioner 100. After the refrigerant passes through the electronic expansion valve 40, it is necessary to ensure that the refrigerant temperature entering the refrigerant ring 50 in the electronic control does not drop too low. Specifically, if the temperature is too low, condensation will form below the dew point of the air, which could cause a short circuit in the electronic control. The refrigerant ring 50 is used to dissipate heat from the electronic control, thereby improving its operational reliability. Furthermore, as shown in FIG4 , when the air conditioner 100 is operating in cooling mode, the refrigerant flows in the F direction and out the C direction through the variable flow throttle valve 30. This allows for a wide flow adjustment range, enabling the desired throttling effect to be achieved under different operating conditions and frequencies. This allows the refrigerant flow rate to be automatically adjusted to accommodate load changes during cooling operation. When the air conditioner 100 operates in heating mode, more heat is usually required to be transferred to the indoor space. The refrigerant flows in in the C direction and flows out in the F direction through the variable flow throttle valve 30 without a throttling effect, thereby improving the heating effect of the air conditioner 100.

[0070] More specifically, when the air conditioner 100 is running in cooling mode, the variable flow throttle valve 30 can adjust the refrigerant flow rate. For example, referring to FIG1 , when the air conditioner 100 is running in cooling mode, the refrigerant can flow from the compressor 70 to the outdoor heat exchanger 20 after the reversal of the four-way valve 60. The high-temperature and high-pressure gaseous refrigerant releases heat in the outdoor heat exchanger 20 and condenses into liquid through the air in the outdoor environment. The high-temperature and high-pressure liquid refrigerant first passes through the electronic expansion valve 40. The temperature and pressure of the refrigerant are reduced after passing through the electronic expansion valve 40, and then flows to the cooling The refrigerant flows through the refrigerant ring 50 to dissipate heat for the electronically controlled components. The refrigerant then flows to the variable flow throttle valve 30, which can adjust the flow rate based on the refrigerant pressure. For example, when the refrigerant pressure is low, the refrigerant flow rate can be reduced to ensure the throttling effect and ensure the reliability of the oil return of the compressor 70. When the refrigerant pressure is high, the refrigerant flow rate can be increased to improve the cooling effect of the air conditioner 100. Specifically, when the refrigerant flows to the indoor heat exchanger 10, the refrigerant absorbs heat from the indoor air through the indoor heat exchanger 10, causing the refrigerant to undergo a phase change from liquid to gas, thereby reducing the indoor temperature. After passing through the four-way valve 60, the gaseous refrigerant returns to the compressor 70 to perform work and compression, increasing its pressure and temperature, and becoming a high-temperature and high-pressure gaseous refrigerant. Among them, the indoor heat exchanger 10 can be an evaporator, and the outdoor heat exchanger 20 can be a condenser. When the air conditioner 100 is in cooling operation, the flow rate of the refrigerant can be adjusted by using a variable flow throttle valve 30 instead of an electronic expansion valve, which can reduce costs. Using a variable flow throttle valve 30 instead of a capillary tube can realize automatic adjustment of the refrigerant flow rate.

[0071] When the air conditioner 100 is operating in heating mode, the refrigerant can flow from the compressor 70 to the indoor heat exchanger 10 after the reversal of the four-way valve 60. The high-temperature and high-pressure gaseous refrigerant releases heat in the indoor heat exchanger 10, and the refrigerant is cooled and condensed into liquid through contact with the indoor air, and releases heat to increase the indoor temperature, and then flows to the variable flow throttle valve 30. When the air conditioner 100 is heating, the variable flow throttle valve 30 does not throttle, and flows to the electronic expansion valve 40 after passing through the refrigerant ring 50 to reduce the pressure of the refrigerant, and the flow rate of the refrigerant can be reduced through the electronic expansion valve 40. By reducing the flow rate of the refrigerant, the residence time of the refrigerant in the outdoor heat exchanger 20 can be increased, so that more heat can be absorbed and transferred to the refrigerant, thereby improving the heating effect, and it can also avoid overheating of the refrigerant in the indoor heat exchanger 10, and avoid overheating and causing a reduction in the heating effect. The low-temperature, low-pressure gaseous refrigerant absorbs heat from the air in the outdoor heat exchanger 20, causing the refrigerant to undergo a phase change from gas to liquid. After passing through the four-way valve 60, it returns to the compressor 70 to perform work and compression, increasing its pressure and temperature, and becoming a high-temperature, high-pressure gaseous refrigerant.

[0072] When the outdoor ambient temperature is low, the temperature of the outdoor heat exchanger 20 may drop below 0 degrees Celsius. Frost will gradually form on the outdoor heat exchanger 20. Once the frost reaches a certain thickness, it will seriously affect the heating effect of the air conditioner 100. Therefore, when the air conditioner 100 is operating in the non-reversing defrost mode, the opening of the electronic expansion valve 40 can be adjusted to increase the refrigerant flow in the pipeline, ensuring a defrosting effect during non-reversing defrost. In other words, the refrigerant flow is increased by the electronic expansion valve 40, ensuring that a large amount of refrigerant flows to the outdoor heat exchanger 20, thereby utilizing the sensible heat of the high-temperature refrigerant to treat the frost on the surface of the outdoor heat exchanger 20. Furthermore, during the process of increasing the opening of the electronic expansion valve 40, the opening changes in stages. That is, when the air conditioner 100 is not reversing for defrosting, the electronic expansion valve 40 needs to be opened wider to increase the flow rate. This results in a larger opening span. If the opening changes too quickly, abnormal refrigerant noise may occur, while if the opening changes too slowly, the defrosting effect may be affected. Therefore, changing the opening in stages can reduce problems such as abnormal refrigerant noise and improve the defrosting effect. The indoor heat exchanger 10 may be a condenser, and the outdoor heat exchanger 20 may be an evaporator.

[0073] Therefore, when the air conditioner is operating in cooling mode, the variable flow throttle valve is configured to automatically adjust the refrigerant flow rate to accommodate load changes during cooling operation. The electronic expansion valve is configured to open wider and in stages during non-reversing defrosting operation. This enables low-cost non-reversing defrosting and reduces the risk of short-circuiting and burning of the electronic control. It also ensures heating performance at low refrigerant flow rates, throttling performance at low loads, and reliable compressor oil return. Furthermore, it ensures sufficient flow and cooling performance during high loads.

[0074] According to one embodiment of the present disclosure, as shown in Figure 1, the air conditioner 100 also includes: a controller 80 (not shown in the figure), and the controller 80 is configured to determine the lower limit opening of the electronic expansion valve 40 according to the outdoor ambient temperature when the air conditioner 100 is in cooling operation, and limit the opening of the electronic expansion valve 40 according to the lower limit opening.

[0075] Specifically, when the air conditioner 100 is operating in cooling mode, the controller 80 can determine the lower limit opening of the electronic expansion valve 40 according to the outdoor ambient temperature. For example, the electronic expansion valve 40 can be controlled according to the outdoor ambient temperature to limit the opening of the electronic expansion valve 40. For example, the outdoor ambient temperature can be obtained through an outdoor temperature sensor. Different outdoor ambient temperatures have different effects on the opening size when controlling the electronic expansion valve 40. For example, the higher the outdoor ambient temperature, the larger the lower limit opening of the electronic expansion valve 40, and the lower the outdoor ambient temperature, the smaller the lower limit opening of the electronic expansion valve 40, thereby preventing the pipe temperature in the refrigerant ring from being lower than the dew point temperature corresponding to its surrounding environment. The air will produce condensation water in the refrigerant ring, causing it to short-circuit and burn the electronic control or even the entire machine. In addition, the opening size setting is more reasonable, while ensuring reliability, giving full play to the cooling capacity.

[0076] In addition, the electronic expansion valve 40 can also be controlled according to the temperature range of the outdoor ambient temperature to limit the opening of the electronic expansion valve 40. For example, the outdoor ambient temperature can be obtained through an outdoor temperature sensor, and the temperature range of the outdoor ambient temperature can be determined. Different temperature ranges have different opening sizes when controlling the electronic expansion valve 40. For example, the higher the outdoor ambient temperature is, the larger the lower limit opening of the electronic expansion valve 40 is, and the lower the outdoor ambient temperature is, the smaller the lower limit opening of the electronic expansion valve 40 is, thereby preventing the pipe temperature in the refrigerant ring from being lower than the dew point temperature corresponding to its surrounding environment. The air will produce condensation water in the refrigerant ring, causing it to short-circuit and burn the electronic control or even the entire machine. In addition, the opening size setting is more reasonable, while ensuring reliability, the cooling capacity is fully utilized.

[0077] According to one embodiment of the present disclosure, the controller 80 is further configured to set the first opening value to the lower limit opening when the outdoor ambient temperature is less than or equal to a first preset outdoor temperature; determine the lower limit opening according to a preset linear relationship when the outdoor ambient temperature is greater than the first preset outdoor temperature and less than or equal to a second preset outdoor temperature; and set the second opening value to the lower limit opening when the outdoor ambient temperature is greater than the second preset outdoor temperature. The preset linear relationship is a linear function with the outdoor ambient temperature as a variable, the first opening value is less than the minimum value of the preset linear relationship, and the maximum value of the preset linear relationship is less than the second opening value. The first preset outdoor temperature and the second preset outdoor temperature can be determined according to actual conditions, and the first opening value and the second opening value can be determined according to actual conditions.

[0078] Specifically, when the air conditioner 100 is operating in cooling mode, the current electronic expansion valve is typically set to a fixed lower limit opening to prevent condensation from forming when the over-throttled refrigerant flows through the refrigerant ring 50, which could cause a short circuit in the electronic control. However, the actual dew point temperature varies with the outdoor ambient temperature. Therefore, a more reasonable lower limit opening is required for different ambient temperatures to ensure reliability while fully utilizing the refrigeration system's regulatory capabilities. Therefore, the purpose of controlling the lower limit opening of the electronic expansion valve 40 when the air conditioner is operating in cooling mode is to prevent condensation from forming on the refrigerant ring 50 during cooling, which could cause a short circuit and burn in the electronic control. If the refrigerant is over-throttled when passing through the electronic expansion valve 40, the pipe temperature in the refrigerant ring 50 will drop below the dew point temperature of the surrounding environment. This will cause condensation to form on the refrigerant ring 50. Since the refrigerant ring 50 is in direct contact with the electronic control board, the condensation can contact components within the board, causing a short circuit and burning of the electronic control, or even the entire unit, posing a significant safety hazard.

[0079] The outdoor ambient temperature is judged. When the outdoor ambient temperature is less than or equal to the first preset outdoor temperature, for example, the first preset outdoor temperature can be set to 20 degrees Celsius. The outdoor ambient temperature can be obtained through a temperature sensor. For example, when the obtained outdoor ambient temperature is 15 degrees Celsius, the first opening value can be set to the lower limit opening of the electronic expansion valve 40. For example, the opening value of 370 pulses is used as the lower limit opening of the electronic expansion valve 40.

[0080] The outdoor ambient temperature is determined. When the outdoor ambient temperature is greater than a first preset outdoor temperature and less than or equal to a second preset outdoor temperature (for example, the first preset outdoor temperature can be set to 20 degrees Celsius and the second preset outdoor temperature can be set to 40 degrees Celsius), when the obtained outdoor ambient temperature is 30 degrees Celsius, the lower limit opening of the electronic expansion valve 40 can be determined according to a preset linear relationship. Specifically, the preset linear relationship is a linear function with the outdoor ambient temperature as a variable, and each outdoor ambient temperature corresponds to a lower limit opening of the electronic expansion valve 40. After determining the outdoor ambient temperature, the lower limit opening of the electronic expansion valve 40 can be obtained according to the preset linear relationship, and the first opening value is less than the minimum value of the preset linear relationship. For example, the preset linear relationship can be Lrmin = a*T4 + b, where a can be 2.5, b can be 320, T4 is the outdoor ambient temperature, and Lrmin is the lower limit opening of the electronic expansion valve 40. Thus, after determining the outdoor ambient temperature T4, the lower limit opening of the electronic expansion valve 40 can be determined according to the preset linear relationship.

[0081] When the outdoor ambient temperature is determined to be greater than a second preset outdoor temperature, for example, when the acquired outdoor ambient temperature is 50 degrees Celsius, which is greater than the second preset outdoor temperature of 40 degrees Celsius, the second opening value can be set as the lower limit opening of the electronic expansion valve 40. For example, an opening of 420 pulses is set as the lower limit opening of the electronic expansion valve 40. In addition, the maximum value of the preset linear relationship is less than the second opening value.

[0082] According to one embodiment of the present disclosure, the controller 80 is also configured to obtain the current opening of the electronic expansion valve 40 when the air conditioner 100 is not reversing to defrost operation, and to adjust the opening of the electronic expansion valve 40 multiple times according to the current opening, so that the opening of the electronic expansion valve 40 changes in stages.

[0083] Specifically, when the air conditioner 100 operates in the non-reversing defrost mode, the electronic expansion valve 40 needs to be opened wider to increase the flow rate. However, the opening span is relatively large. If the opening changes too quickly during this process, abnormal refrigerant noise may be generated, while if the opening changes too slowly, the defrosting effect may be affected. Therefore, when the air conditioner 100 operates in the non-reversing defrost mode, the controller 80 can obtain the current opening of the electronic expansion valve 40. After obtaining the current opening of the electronic expansion valve 40, the opening of the electronic expansion valve 40 can be adjusted multiple times based on the current opening. For example, the opening can be increased by a preset opening value each time, so that the opening of the electronic expansion valve 40 changes in stages, thereby reducing problems such as abnormal refrigerant noise.

[0084] According to one embodiment of the present disclosure, the controller 80 is also configured to determine the target opening and the number of opening adjustments of the electronic expansion valve 40, and determine the adjustment step according to the current opening, the target opening and the number of opening adjustments, and to adjust the opening of the electronic expansion valve 40 multiple times according to the adjustment step.

[0085] Specifically, when the air conditioner 100 operates in the non-reversing defrost mode, the electronic expansion valve 40 needs to be opened wider to increase flow. However, the opening span is relatively large. If the opening changes too quickly during this process, abnormal refrigerant noise may occur, while if it changes too slowly, the defrosting effect may be affected. Therefore, when the air conditioner 100 operates in the non-reversing defrost mode, the controller 80 can obtain the current opening of the electronic expansion valve 40. After obtaining the current opening of the electronic expansion valve 40, the target opening and the number of opening adjustments can be determined. After determining the target opening and the number of opening adjustments, the adjustment step size can be determined based on the current opening, the target opening, and the number of opening adjustments. For example, the adjustable opening Lr of the electronic expansion valve 40 can be calculated according to the formula: Lr = (Lraim - Lrx) / N, where Lr is the adjustable opening of the electronic expansion valve 40, Lraim is the target opening, Lrx is the current opening, and N is the number of opening adjustments, which can be 6.

[0086] Therefore, after determining the adjustment step size of the electronic expansion valve 40 based on the current opening, the target opening, and the number of opening adjustment steps, the opening of the electronic expansion valve 40 can be repeatedly increased according to the adjustment step size. Specifically, when increasing the opening of the electronic expansion valve 40, the opening of the electronic expansion valve 40 can be adjusted by a maximum of Lr each time within a preset time period, such as 5 seconds, until the target opening is reached through multiple increasing adjustments. The target opening can be determined based on the amount of heat required for defrosting. Thus, by repeatedly increasing the opening, problems such as abnormal refrigerant noise can be mitigated.

[0087] According to one embodiment of the present disclosure, the air conditioner 100 further includes: a controller 80, which is further configured to obtain at least one of the indoor ambient temperature, the outdoor ambient temperature, and the outdoor heat exchanger temperature, and determine that the air conditioner 100 does not reverse to defrost operation based on at least one of the indoor ambient temperature, the outdoor ambient temperature, and the outdoor heat exchanger temperature.

[0088] Furthermore, according to one embodiment of the present disclosure, the controller 80 controls the air conditioner 100 not to switch to the defrost mode when it is determined that any of the following conditions are not met: (1) the indoor ambient temperature is less than the first preset temperature, or the outdoor ambient temperature is less than the second preset temperature, or the sum of the indoor ambient temperature and the outdoor ambient temperature is less than the third preset temperature; (2) the change in the temperature of the outdoor heat exchanger 20 is less than the fourth preset temperature; (3) the outdoor ambient temperature is less than the fifth preset temperature and the air conditioner 100 does not enter the defrost mode within the second preset time, wherein the fifth preset temperature is greater than the second preset temperature. The first preset temperature, the second preset temperature, the third preset temperature, the fourth preset temperature, and the fifth preset temperature can be determined according to actual conditions.

[0089] Specifically, when determining whether the air conditioner 100 has entered the non-reversing defrost mode, the determination may be made based on the following preset conditions: the outdoor ambient temperature is compared with a first preset temperature, the indoor ambient temperature is compared with a second preset temperature, and the sum of the indoor ambient temperature and the outdoor ambient temperature is compared with a third preset temperature. When the indoor ambient temperature is less than the first preset temperature, or the outdoor ambient temperature is less than the second preset temperature, or the sum of the indoor ambient temperature and the outdoor ambient temperature is less than the third preset temperature, the first determination condition may be determined to be satisfied.

[0090] The temperature change of the outdoor heat exchanger 20 is compared with a fourth preset temperature. If the temperature change of the outdoor heat exchanger 20 is less than the fourth preset temperature, the second judgment condition is determined to be satisfied. The temperature change of the outdoor heat exchanger 20 can be calculated based on the temperature change of the outdoor heat exchanger 20 over a period of time.

[0091] The outdoor ambient temperature is compared with the fifth preset temperature. When the outdoor ambient temperature is lower than the fifth preset temperature, it is also necessary to determine whether the air conditioner 100 enters the defrost mode within the second preset time. When the outdoor ambient temperature is lower than the fifth preset temperature and the air conditioner 100 does not enter the defrost mode within the second preset time, it can be determined that the third judgment condition is met.

[0092] Therefore, when the first judgment condition, the second judgment condition, and the third judgment condition are all not satisfied, the controller 80 may control the air conditioner 100 to enter the non-reversing defrost mode.

[0093] Furthermore, upon determining that any one of the preset conditions is satisfied, the controller 80 may control the four-way valve 60 to reverse direction, causing the air conditioner 100 to enter the reverse defrost mode. For example, when the indoor ambient temperature is less than a first preset temperature, or the outdoor ambient temperature is less than a second preset temperature, or the sum of the indoor and outdoor ambient temperatures is less than a third preset temperature, the four-way valve 60 may be controlled to reverse direction, causing the air conditioner 100 to enter the reverse defrost mode. For another example, when the temperature change of the outdoor heat exchanger 20 is less than a fourth preset temperature, the four-way valve 60 may be controlled to reverse direction, causing the air conditioner 100 to enter the reverse defrost mode. For another example, when the outdoor ambient temperature is less than a fifth preset temperature and the air conditioner 100 has not entered the defrost mode within a second preset time, the four-way valve 60 may be controlled to reverse direction, causing the air conditioner 100 to enter the reverse defrost mode.

[0094] When the air conditioner 100 enters the reversing defrost mode, the controller 80 controls the compressor 70 to stop and then switches the direction of the four-way valve 60, and then starts the compressor 70 again to run in the defrosting mode, that is, runs in the cooling mode to defrost the outdoor heat exchanger 20.

[0095] According to one embodiment of the present disclosure, the controller 80 is further configured to obtain a first temperature change value of the outdoor heat exchanger 20 and a second temperature change value of the outdoor ambient temperature within a third preset time period; and determine a temperature change value of the outdoor heat exchanger 20 based on a relationship between the first temperature change value and the second temperature change value, wherein a preset coefficient is determined by the magnitude of the second temperature change value. The third preset time period can be determined based on actual circumstances.

[0096] Specifically, when determining the temperature change value of the outdoor heat exchanger 20, since changes in the outdoor ambient temperature can affect the temperature change of the outdoor heat exchanger 20, when the air conditioner 100 is operating in a non-reversing defrost mode, the determined value of the temperature change value of the outdoor heat exchanger 20 is relatively small, and therefore needs to be corrected. Specifically, after the air conditioner 100 is in heating mode and the compressor 70 is activated, a first temperature change value of the outdoor heat exchanger 20 and a second temperature change value of the outdoor ambient temperature are obtained within a third preset time. Specifically, at the beginning of the third preset time, the temperature of the outdoor heat exchanger 20 can be recorded as T30, and at the end of the third preset time, the temperature of the outdoor heat exchanger 20 can be recorded as T3, along with the outdoor ambient temperatures at the corresponding times, T40 and T4. Thus, the temperature change value of the outdoor heat exchanger 20 can be determined based on the relationship between the first temperature change value and the second temperature change value. For example, the temperature change value of the outdoor heat exchanger 20 can be determined by multiplying the first temperature change value by a preset coefficient. The temperature change of the outdoor heat exchanger 20 can be calculated as ΔT3 = (T3 - T30) - M * (T4 - T40). M is a preset coefficient that can be set in stages based on the outdoor ambient temperature and the temperature change of the outdoor heat exchanger 20. For example, when |T4 - T40| ≥ 6°C, the value of M can be 1, and when |T4 - T40| < 6°C, the value of M can be 0.9.

[0097] According to one embodiment of the present disclosure, the controller 80 is further configured to control the air conditioner 100 to enter a first non-reversing defrost mode when the temperature change of the outdoor heat exchanger 20 is less than a sixth preset temperature; and to control the air conditioner 100 to enter a second non-reversing defrost mode when the temperature change of the outdoor heat exchanger 20 is less than a seventh preset temperature. The seventh preset temperature is less than the sixth preset temperature, and the sixth preset temperature is greater than the fourth preset temperature. The sixth and seventh preset temperatures can be determined based on actual conditions.

[0098] Specifically, when controlling the air conditioner 100 to enter the non-reversing defrost mode, whether to enter the first non-reversing defrost mode or the second reversing defrost mode can be determined based on the temperature change of the outdoor heat exchanger 20. The temperature change of the outdoor heat exchanger 20 is compared with a sixth preset temperature. When the temperature change of the outdoor heat exchanger 20 is less than the sixth preset temperature, the air conditioner 100 can be controlled to enter the first non-reversing defrost mode. When the temperature change of the outdoor heat exchanger 20 is less than a seventh preset temperature, the air conditioner 100 can be controlled to enter the second non-reversing defrost mode. The seventh preset temperature is less than the sixth preset temperature, and the sixth preset temperature is greater than the fourth preset temperature.

[0099] That is, when the temperature change of the outdoor heat exchanger 20 is less than the sixth preset temperature, it means that the frost layer on the outdoor heat exchanger 20 is relatively thin and the temperature change of the outdoor heat exchanger 20 is relatively large, and the first non-reversing defrost mode can be entered to melt the frost layer on the outdoor heat exchanger 20. When the temperature change of the outdoor heat exchanger 20 is less than the seventh preset temperature, it means that the frost layer on the outdoor heat exchanger 20 is relatively thick and the temperature change of the outdoor heat exchanger 20 is relatively small, and the second non-reversing defrost mode can be entered to melt the frost layer on the outdoor heat exchanger 20.

[0100] According to one embodiment of the present disclosure, the controller 80 is further configured to, when the air conditioner 100 is operating in the first non-reversing defrost mode, control the air conditioner 100 to exit the first non-reversing defrost mode if no change in the opening of the electronic expansion valve 40 is detected, if the temperature of the outdoor heat exchanger 20 is greater than an eighth preset temperature or the operating time of the first non-reversing defrost mode is greater than a third preset time. If a change in the opening of the electronic expansion valve 40 is detected, the controller 80 delays for a fourth preset time and then determines whether to exit the first non-reversing defrost mode based on the temperature of the outdoor heat exchanger 20. The eighth preset temperature can be determined based on actual conditions, and the third and fourth preset times can be determined based on actual conditions.

[0101] Specifically, the current defrost mode of the air conditioner 100 is determined. When the air conditioner 100 is operating in the first non-reversing defrost mode, the opening of the electronic expansion valve 40 is determined, the temperature of the outdoor heat exchanger 20 is compared with an eighth preset temperature, and the operating time of the first non-reversing defrost mode is determined. If the controller 80 does not detect a change in the opening of the electronic expansion valve 40 and the temperature of the outdoor heat exchanger 20 is greater than the eighth preset temperature, it indicates that defrosting of the outdoor heat exchanger 20 is currently complete, and the air conditioner 100 may be controlled to exit the first non-reversing defrost mode. Alternatively, if the controller 80 does not detect a change in the opening of the electronic expansion valve 40 and the operating time of the first non-reversing defrost mode is greater than a third preset time, it indicates that defrosting of the outdoor heat exchanger 20 is currently complete, and the air conditioner 100 may be controlled to exit the first non-reversing defrost mode.

[0102] The current defrost mode of the air conditioner 100 is determined. When the air conditioner 100 is operating in the first non-reversing defrost mode, the opening of the electronic expansion valve 40 is determined. If the opening of the electronic expansion valve 40 changes, it indicates that the opening of the electronic expansion valve 40 is still increasing to defrost the outdoor heat exchanger 20. To ensure stability of the temperature change of the outdoor heat exchanger 20, a fourth preset time may be delayed (for example, the fourth preset time may be 30 seconds). Then, a determination is made as to whether the air conditioner 100 has exited the first non-reversing defrost mode based on the temperature of the outdoor heat exchanger 20. That is, if the controller 80 does not detect a change in the opening of the electronic expansion valve 40, and if the temperature of the outdoor heat exchanger 20 is greater than the eighth preset temperature, or if the operating time of the first non-reversing defrost mode is greater than the third preset time, the air conditioner 100 is controlled to exit the first non-reversing defrost mode.

[0103] According to one embodiment of the present disclosure, the controller 80 is further configured to, when the air conditioner 100 is operating in the second non-reversing defrost mode, control the air conditioner 100 to exit the second non-reversing defrost mode if no change in the opening of the electronic expansion valve 40 is detected, and if the temperature of the outdoor heat exchanger 20 is greater than a ninth preset temperature or the operating time of the second non-reversing defrost mode is greater than a fifth preset time. If a change in the opening of the electronic expansion valve 40 is detected, control the air conditioner 100 to exit the second non-reversing defrost mode after a sixth preset time delay based on the temperature of the outdoor heat exchanger 20. The ninth preset temperature is greater than the eighth preset temperature, and the fifth preset time is greater than the third preset time. The ninth preset temperature can be determined based on time conditions, and the fifth and sixth preset times can be determined based on actual conditions.

[0104] Specifically, the current defrost mode of the air conditioner 100 is determined. When the air conditioner 100 is operating in the second non-reversing defrost mode, the opening of the electronic expansion valve 40 is determined, the temperature of the outdoor heat exchanger 20 is compared with a ninth preset temperature, and the operating time of the second non-reversing defrost mode is determined. If the controller 80 does not detect a change in the opening of the electronic expansion valve 40 and the temperature of the outdoor heat exchanger 20 is greater than the ninth preset temperature, where the ninth preset temperature is greater than the eighth preset temperature, it indicates that defrosting of the outdoor heat exchanger 20 is currently complete, and the air conditioner 100 may be controlled to exit the second non-reversing defrost mode. Alternatively, if the controller 80 does not detect a change in the opening of the electronic expansion valve 40 and the operating time of the second non-reversing defrost mode is greater than the fifth preset time, it indicates that defrosting of the outdoor heat exchanger 20 is currently complete, and the air conditioner 100 may be controlled to exit the second non-reversing defrost mode.

[0105] The current defrost mode of the air conditioner 100 is determined. When the air conditioner 100 is operating in the second non-reversing defrost mode, the opening of the electronic expansion valve 40 is determined. If the opening of the electronic expansion valve 40 changes, it indicates that the opening of the electronic expansion valve 40 is still increasing to defrost the outdoor heat exchanger 20. To ensure stability of the temperature change of the outdoor heat exchanger 20, a delay of a sixth preset time (for example, 40 seconds) may be performed before determining whether the air conditioner 100 has exited the second non-reversing defrost mode based on the temperature of the outdoor heat exchanger 20. That is, if the controller 80 does not detect a change in the opening of the electronic expansion valve 40, and if the temperature of the outdoor heat exchanger 20 is greater than the ninth preset temperature or the operating time of the second non-reversing defrost mode is greater than the fifth preset time, the air conditioner 100 is controlled to exit the first non-reversing defrost mode.

[0106] According to one embodiment of the present disclosure, the controller 80 is further configured to determine a ninth preset temperature according to a change trend of the outdoor ambient temperature and the current outdoor ambient temperature.

[0107] Specifically, since the air conditioner 100 defrosts for a shorter time when in the first non-reversing defrost mode and for a longer time when in the second non-reversing defrost mode, the ninth preset temperature may also be determined based on a changing trend of the outdoor ambient temperature and the current outdoor ambient temperature. For example, when the air conditioner 100 defrosts in the second non-reversing defrost mode, the changing trend of the outdoor ambient temperature and the current outdoor ambient temperature are obtained. For example, if the outdoor ambient temperature is rising and is less than or equal to 1 degree Celsius, the ninth preset temperature may be determined to be 14 degrees Celsius. That is, when the temperature of the outdoor heat exchanger 20 exceeds 14 degrees Celsius, the current defrost mode may be exited and normal heating of the air conditioner 100 may be resumed. If the outdoor ambient temperature is greater than 1 degree Celsius, the ninth preset temperature may be determined to be 18 degrees Celsius. That is, when the temperature of the outdoor heat exchanger 20 exceeds 18 degrees Celsius, the current defrost mode may be exited and normal heating of the air conditioner 100 may be resumed.

[0108] Obtain the changing trend of the outdoor ambient temperature, and obtain the current outdoor ambient temperature. For example, when the outdoor ambient temperature is in the process of decreasing, when the outdoor ambient temperature is less than or equal to -1 degree Celsius, the ninth preset temperature can be determined to be 14 degrees Celsius, that is, when the temperature of the outdoor heat exchanger 20 exceeds 14 degrees Celsius, the current defrost mode can be exited and the normal heating of the air conditioner 100 can be restored; when the outdoor ambient temperature is greater than -1 degree Celsius, the ninth preset temperature can be determined to be 18 degrees Celsius, that is, when the temperature of the outdoor heat exchanger 20 exceeds 18 degrees Celsius, the current defrost mode can be exited and the normal heating of the air conditioner 100 can be restored.

[0109] In this way, it is possible to ensure that there are more reasonable judgment conditions for the temperature when defrosting exits, and balance the defrosting cleanliness and user experience.

[0110] According to one embodiment of the present disclosure, the controller 80 is further configured to, when the air conditioner 100 enters a first non-reversing defrost mode, control the compressor 70 to operate at a first operating frequency, shut down the outdoor fan, and maintain a constant speed of the indoor fan; and, when the air conditioner 100 enters a second non-reversing defrost mode, control the compressor 70 to operate at a second operating frequency, shut down the outdoor fan, and reduce the speed of the indoor fan at a preset rate; wherein the first operating frequency is lower than the second operating frequency. The first operating frequency and the second operating frequency can be determined based on actual conditions.

[0111] Specifically, when it is determined that the air conditioner 100 enters the first non-reversing defrost mode, the controller 80 can control the compressor 70 not to stop and to operate at the first operating frequency, and control the outdoor fan to stop. If the outdoor fan continues to run, it may cause more air to pass through the outdoor heat exchanger 20, resulting in more severe frosting, and control the speed of the indoor fan to remain unchanged, thereby ensuring that the indoor temperature will not drop while quickly defrosting.

[0112] When it is determined that the air conditioner 100 enters the second non-reversing defrost mode, the compressor 70 can be controlled not to stop and to operate at a second operating frequency, wherein the second operating frequency is greater than the first operating frequency, and the outdoor fan is controlled to stop. If the outdoor fan continues to run, it may cause more air to pass through the outdoor heat exchanger 20, resulting in more severe frosting, and the speed of the indoor fan is controlled to decrease at a preset rate to prevent the temperature entering the outdoor heat exchanger 20 from being low, resulting in more severe frosting.

[0113] According to one embodiment of the present disclosure, the electronic expansion valve 80 is a wide-range variable gain electronic expansion valve. Compared with the traditional electronic expansion valve, the upper limit flow rate can be increased while maintaining the lower limit flow rate. That is, when the air conditioner 100 is in a non-reversing defrost mode, a larger refrigerant flow rate can be passed, thereby better defrosting the air conditioner 100.

[0114] According to an embodiment of the present disclosure, the wide-range variable gain electronic expansion valve is further configured to change its opening degree based on load changes when the air conditioner 100 is in heating operation.

[0115] Specifically, when the air conditioner 100 is operating in heating mode, the wide-range variable gain electronic expansion valve can change its opening based on changes in load. For example, the wide-range variable gain electronic expansion valve can be equipped with corresponding sensors to monitor air conditioning system parameters such as temperature and pressure. After obtaining the parameters, the data can be sent to the controller 80. The controller 80 can determine whether the wide-range variable gain electronic expansion valve needs to be adjusted by comparing the difference between the current system load and the target load. If the system load increases, the controller 80 can control the wide-range variable gain electronic expansion valve to open more to provide more refrigerant flow; conversely, if the system load decreases, the controller can control the wide-range variable gain electronic expansion valve to open less. This can improve the energy efficiency of the air conditioner 100 during heating, reduce energy consumption, and ensure stable system performance under different operating conditions.

[0116] According to one embodiment of the present disclosure, as shown in Figure 5, a wide-band variable-gain electronic expansion valve includes a valve body 41 having an inlet and an outlet. A valve seat 42 is provided at the outlet, and a valve needle 43 is provided on the valve seat 42. The gap between the valve needle 43 and the valve seat 42 forms a throttling orifice. The adjustment section of the valve needle 43 is designed with multiple angles. The caliber of the valve seat 42 ranges from 1.6 mm to 3.2 mm.

[0117] Specifically, a throttle hole 44 is provided on the valve seat 42, connecting the inner cavity of the valve body 41 with the outlet pipe. This allows the refrigerant in the pipeline to flow through the throttle hole 44. Furthermore, a valve stem 45 is connected to the valve needle 43. By controlling the movement of the valve stem 45, the size of the throttle hole 44 can be adjusted. For example, when the valve stem 45 is moved upward, the size of the throttle hole 44 can be increased, while when the valve stem 45 is moved downward, the size of the throttle hole 44 can be decreased, thereby controlling the flow rate of the refrigerant in the pipeline. The valve body 41 can be made of brass.

[0118] As shown in Figure 6, the valve needle 43 can be trapezoidal. By designing the valve needle 43 in a trapezoidal shape and increasing the range of valve seat 42 diameters (i.e., by increasing the valve seat width of the wide-gain variable-gain electronic expansion valve), the upper limit of the refrigerant flow in the pipeline is increased while maintaining the lower limit of the refrigerant flow, compared to traditional electronic expansion valves. This allows for a greater flow of refrigerant to pass, allowing the air conditioner 100 to defrost without switching to another direction. This larger refrigerant flow can alter the heat exchange effect between the outdoor heat exchanger 20 and the frost layer, helping to ensure that sufficient heat is transferred to the ice layer during the defrost process for more efficient melting. Furthermore, the trapezoidal design of the valve needle 43 improves flow rate regulation accuracy. Compared to other shapes, the trapezoidal shape allows for more precise adjustment of the refrigerant flow rate and more flexible response to electronic control adjustment signals, improving response speed. Furthermore, the valve needle 43 can be adjusted at multiple angles (within the range α) to adjust the refrigerant flow in the pipeline. The diameter of the valve seat 42 can range from 1.6 mm to 3.2 mm.

[0119] Furthermore, the valve needle 43 can be configured in a tapered shape to help reduce the pressure differential when the electronic expansion valve 40 is started, thereby lowering startup power consumption and improving efficiency. Furthermore, the valve seat 42 can be designed with a smaller diameter to reduce weight and reduce the load on the entire electronic expansion valve 40. Furthermore, in air conditioning systems with limited space, the compact valve seat design can effectively save space and minimize the volume of refrigerant flowing, helping to reduce the system's internal volume, thereby lowering energy consumption and refrigerant usage.

[0120] According to one embodiment of the present disclosure, as shown in FIG7 , the variable flow throttle valve 30 includes: a housing 81, a mounting channel 82 is formed in the housing 81, the housing 81 has a first medium flow port 83 and a second medium flow port 84, the mounting channel 82 communicates with the first medium flow port 83 and the second medium flow port 84; a first valve seat 85, the first valve seat 85 is mounted in the mounting channel 82, the first valve seat 85 is formed with an adjacent first hole 86 and a first medium flow channel 87, the first medium flow channel 87 communicates with the first medium flow port 83 and the first hole 86, the first hole 86 is suitable for communicating with the first medium flow channel 87 and the second medium flow port 83. 4; the first valve seat 85 is further formed with an adjacent second hole 88 and a second medium flow channel 89, the second medium flow channel 89 communicating with the second medium flow port 84 and the second hole 88, and the second hole 88 is adapted to communicate with the first medium flow port 83 and the second medium flow channel 89; a first valve core 90 (not shown in the figure), the first valve core 90 is disposed in the first medium flow channel 87, and the first valve core 90 is movable along the first medium flow channel 87 to open or close the first hole 86; a second valve core 91 (not shown in the figure), the second valve core 91 is disposed in the second medium flow channel 89, and the second valve core 91 is movable along the second medium flow channel 89 to open or close the second hole 88.

[0121] Specifically, the variable flow throttle valve 30 may include a shell 81. The material of the shell 81 may be stainless steel, that is, it has the characteristics of corrosion resistance, high temperature resistance, and high strength, which can ensure the stability and reliability of the air-conditioning system. The shell 81 has a first medium flow port 83 and a second medium flow port 84. When the air conditioner 100 operates in different modes, the flow direction of the medium inside the variable flow throttle valve 30 is different. As shown in Figure 7, when the air conditioner 100 operates in the cooling mode, the medium can flow from the first medium flow port 83 to the second medium flow port 84 (that is, in the direction from end F to end C), and when the air conditioner 100 operates in the heating mode, the medium can flow from the second medium flow port 84 to the first medium flow port 83 (that is, in the direction from end C to end F). A mounting channel 82 is formed in the shell 81, and the first medium flow port 83 is connected to the second medium flow port 84 through the mounting channel 82.

[0122] The variable flow throttle valve 30 also includes a first valve seat 85, which is formed with an adjacent first orifice 86 and a first medium flow channel 87. A first valve core 90 is disposed within the first medium flow channel 87, allowing the first valve core 90 to move along the first medium flow channel 87 to open or close the first orifice 86. For example, when the first valve core 90 moves upward, it gradually opens the first orifice 86, allowing the flow of medium. When the first valve core 90 moves downward, it gradually closes the first orifice 86, restricting the flow of medium. When the first orifice 86 is open, the medium can flow from the second medium flow port 84 to the first orifice 86, and then to the first medium flow channel 87, ultimately flowing out through the first medium flow port 83.

[0123] The first valve seat 85 may also be formed with an adjacent second hole 88 and a second medium flow channel 89. A second valve core 91 is disposed within the second medium flow channel 89, allowing the second valve core 91 to move along the second medium flow channel 89 to open or close the second hole 88. For example, when the second valve core 91 moves downward, the second hole 88 is gradually opened, allowing the medium to pass through. When the second valve core 91 moves upward, the second hole 82 is gradually closed, restricting the flow of the medium. When the second hole 88 is open, the medium can flow from the first medium flow port 83 to the second hole 82, and then to the second medium flow channel 89, and finally out through the second medium flow port 84.

[0124] According to one embodiment of the present disclosure, as shown in Figure 7, when the medium flows into the installation channel 82 through the first medium flow port 83, the medium drives the first valve core 90 to move to close the first hole 86 and drives the second valve core 91 to move to open the second hole 88; when the medium flows into the installation channel 82 through the second medium flow port 89, the medium drives the first valve core 90 to move to open the first hole 86 and drives the second valve core 91 to move to close the second hole 88; wherein, along the length direction of the installation channel 82, the first hole 86 and the second hole 88 are located between the first medium flow channel 87 and the second medium flow channel 89.

[0125] Specifically, when the air conditioner 100 is operating in cooling mode, medium can flow into the installation passage 82 through the first medium flow port 83. When the medium flows into the installation passage 82 through the first medium flow port 83, the pressure of the inflowing medium can drive the first valve core 90 to move and close the first hole 86, and the second valve core 91 to move and open the second hole 88. The medium will not flow out of the first hole 86, but will flow out of the second hole 88. When the air conditioner 100 is operating in heating mode, medium can flow into the installation passage 82 through the second medium flow port 89. When the medium flows into the installation passage 82 through the second medium flow port 89, the pressure of the inflowing medium can drive the first valve core 90 to move and open the first hole 86, and the second valve core 91 to move and close the second hole 88. The medium will not flow out of the second hole 88, but will flow out of the first hole 86. When the first hole 86 is open, the medium can flow to the first medium flow channel 87 through the first hole 86 , and when the second hole 88 is open, the medium can flow to the second medium flow channel 89 through the second hole 88 .

[0126] According to one embodiment of the present disclosure, as shown in Figure 7, a throttling channel 92 and a conducting channel 93 are also formed in the shell 81, the throttling channel 92 connects the first medium flow port 83 and the second hole 88, and the conducting channel 93 connects the second medium flow port 84 and the first hole 86, wherein the throttling channel 92 and / or the conducting channel 93 are formed on the first valve seat 85.

[0127] Specifically, the variable flow throttle valve 30 can have both throttling and conducting functions, automatically determining whether to throttle or conduct the medium according to the current operating mode of the air conditioner 100. Specifically, a throttling channel 92 and a conducting channel 93 are formed within the housing 81 of the variable flow throttle valve 30. When the air conditioner 100 operates in cooling mode, the medium can flow through the first medium flow port 83 into the throttling channel 92 and toward the second orifice 88. When the air conditioner 100 operates in heating mode, the medium can flow through the second medium flow port 84 into the conducting channel 93 and toward the first orifice 86. Thus, the variable flow throttle valve 30 can achieve different functions depending on the different channels. The throttling channel 92 can be formed on the first valve seat 85, or the conducting channel 93 can be formed on the first valve seat 85, or both the throttling channel 92 and the conducting channel 93 can be formed on the first valve seat 85, thereby enabling the medium to flow toward the first valve seat 85 from different directions.

[0128] According to one embodiment of the present disclosure, as shown in Figure 7, a first communicating flow channel 94 is formed between the first valve seat 85 and the outer shell 81, and the first communicating flow channel 94 connects the throttling channel 92 and the first medium flow port 83; a second communicating flow channel 95 is formed between the first valve seat 85 and the outer shell 81, and the second communicating flow channel 95 connects the conducting channel 93 and the second medium flow port 84.

[0129] Specifically, when the air conditioner 100 operates in cooling mode, the variable flow throttle valve 30 can adjust the flow of the medium. That is, when the medium flows into the installation channel 82 through the first medium flow port 83, the first valve core 90 is driven to move to close the first hole 86, and the second valve core 91 is driven to move to open the second hole 88. When the first hole 86 is closed and the second hole 88 is open, the medium can flow from the first medium flow port 83 to the first connecting flow channel 94, pass through the throttling channel 92, flow to the second hole 88, and finally flow out through the second medium flow port 84, thereby throttling the flow of the medium.

[0130] When the air conditioner 100 is operating in heating mode, the variable flow throttle valve 30 does not regulate the flow of the medium. That is, when the medium flows into the installation channel 82 through the second medium flow port 84, the medium drives the first valve core 90 to open the first hole 86 and drives the second valve core 91 to close the second hole 88. When the first hole 86 is open and the second hole 88 is closed, the medium can flow from the second medium flow port 84 to the second connecting flow channel 95, pass through the conductive channel 93, flow to the first hole 88, and finally flow out through the first medium flow port 83. At this time, no throttling is performed, thereby ensuring the heating effect of the air conditioner. The medium can be a refrigerant.

[0131] According to one embodiment of the present disclosure, as shown in Figure 7, a first limiting member 96 (not shown in the figure) is provided in the first medium flow channel 87, and the first limiting member 96 is located on the side of the first valve core 90 away from the first hole 86. The first limiting member 96 forms a third connecting flow channel 97 connecting the first medium flow channel 87 and the first medium flow port 83, and the first limiting member 96 is suitable for limiting cooperation with the first valve core 90; a second limiting member 98 (not shown in the figure) is provided in the second medium flow channel 89, and the second limiting member 98 is located on the side of the second valve core 91 away from the second hole 88. The second limiting member 98 forms a fourth connecting flow channel 99 connecting the second medium flow channel 89 and the second medium flow port 84, and the second limiting member 98 is suitable for limiting cooperation with the second valve core 91.

[0132] Specifically, by providing a first stopper 96 within the first medium flow channel 87, adapted to cooperate with the first valve core 90 for limiting position, and by providing a second stopper 98 within the second medium flow channel 89, adapted to cooperate with the second valve core 91 for limiting position, the stopper's cooperation limits the range of motion of the valve core within the designed parameter range, thereby preventing the valve core from excessively opening or closing, ensuring that the system operates within a safe and stable range. Furthermore, the correct cooperation between the stopper and the valve core facilitates precise control of the medium flow rate. By ensuring that the valve core stops or is limited at a predetermined position, the desired flow rate level can be maintained without exceeding the designed range.

[0133] The first limiting member 96 forms a third connecting flow channel 97 connecting the first medium flow channel 87 and the first medium flow port 83, and the second limiting member 98 forms a fourth connecting flow channel 99 connecting the second medium flow channel 89 and the second medium flow port 84. Thus, when the medium flows in from the first medium flow port 83, it can flow from the first medium flow port 83 to the first connecting flow channel 94, and flow to the second hole 88 after passing through the throttling channel 92, and then flow from the second hole 88 to the second medium flow channel 89, and flow through the second medium flow channel 89 to the fourth connecting flow channel 99, and finally flow to the second medium flow port 84 and flow out from the second medium flow port 84. When the medium flows in from the second medium flow port 84, it can flow from the second medium flow port 84 to the second connecting flow channel 95, and after passing through the conducting channel 93, flow to the first hole 86, and then flow from the first hole 86 to the first medium flow channel 87, and flow through the first medium flow channel 87 to the third connecting flow channel 97, and finally flow to the first medium flow port 83, and flow out from the first medium flow port 83.

[0134] According to one embodiment of the present disclosure, as shown in Figure 7, the variable flow throttle valve 30 may further include: an elastic member 101, the elastic member 101 is assembled in the second medium flow channel 89 and is located between the second valve core 91 and the second limit member 98, and the elastic member 101 is connected between the second valve core 91 and the second limit member 98.

[0135] According to one embodiment of the present disclosure, as shown in FIG. 7 , the second valve core 91 includes: a connected valve core body 102 (not shown in the figure) and a closing column 103 (not shown in the figure), and the closing column 103 is used to open or close the second hole 88 .

[0136] Specifically, the variable flow throttle valve 30 may also include an elastic member 101. The elastic member 101 has a certain stroke, which can help limit the range of motion of the second valve core 91 and ensure that the second valve core 91 adjusts the flow within an appropriate range. The second valve core 91 may include a connected valve core body 102 and a closing column 103. The position of the valve core body 102 determines the size of the medium passing through the fourth connecting flow channel 99. When the air conditioner 100 is in cooling mode, the medium can flow in from the first medium flow port 83 and flow from the first medium flow port 83 to the first connecting flow channel 94, and then flow to the second hole 88 after passing through the throttling channel 92. At this time, the closing column 103 can open the second hole 88, and then flow from the second hole 88 to the second medium flow channel 89. When the pressure of the medium (such as refrigerant) is low, The deformation of the elastic member 101 is small, which can make the position of the second valve core 91 change less, and the flow rate into the fourth communication flow channel 99 is small, that is, a small flow of refrigerant flows out of the second medium flow port 84, thereby ensuring the throttling effect and ensuring the reliability of the oil return of the compressor 70. When the refrigerant pressure is high, the deformation of the elastic member 101 is large, which can make the position of the second valve core 91 change more, and the flow rate into the fourth communication flow channel 99 is large, that is, a large flow of refrigerant flows out of the second medium flow port 84, thereby improving the cooling effect of the air conditioner 100. The elastic member 101 can be a spring.

[0137] According to one embodiment of the present disclosure, as shown in FIG. 7 , the valve core body 102 is configured as a cylinder, or at least one notch is formed on a sidewall of the valve core body 102 .

[0138] Specifically, the valve core body 102 is designed to be cylindrical. On the one hand, the cylindrical shape is easy to manufacture and maintain. On the other hand, the cylindrical valve core body 102 has a uniform geometric shape, which helps to achieve relatively uniform fluid distribution, avoiding uneven flow velocity when the medium passes through the variable flow throttle valve 30, thereby improving the stability of the air conditioning system. Alternatively, the side wall of the valve core body 102 is formed with at least one notch, for example, two notches, so that vibration during the movement of the valve core body 102 can be reduced, thereby improving the stability of the system. In addition, the provision of the notch can affect the vortex and turbulence generated when the medium passes through the valve core body 102. By adjusting the shape of the notch, these unstable fluid phenomena can be reduced, thereby further improving the efficiency of the system.

[0139] According to one embodiment of the present disclosure, as shown in Figure 7, the variable flow throttle valve 30 may further include: a first filter element 103, the first filter element 103 is installed in the installation channel 82 and is located between the first valve seat 85 and the first medium flow port 83; and a second filter element 104, the second filter element 104 is installed in the installation channel 82 and is located between the first valve seat 85 and the second medium flow port 84.

[0140] Specifically, by disposing a first filter element 103 between the first valve seat 85 and the first medium flow port 83, and a second filter element 104 between the first valve seat 85 and the second medium flow port 84, solid particles, impurities, and sediment in the medium can be blocked from entering the variable flow throttle valve 30, thereby extending the service life of the variable flow throttle valve 30, reducing maintenance frequency, and improving system reliability. Furthermore, if the medium contains easily condensable substances or sediment, these may accumulate within the variable flow throttle valve 30 or in the pipeline when flowing through it, causing clogging of the variable flow throttle valve 30. Disposing the first filter element 103 and the second filter element 104 can reduce the risk of clogging and ensure smooth passage of the fluid through the throttle valve. The first filter element 103 and the second filter element 104 can be filter screens.

[0141] In summary, according to the air conditioner of the disclosed embodiment, the variable flow throttle valve is configured to automatically adjust the refrigerant flow rate to accommodate load changes when the air conditioner is operating in cooling mode. The electronic expansion valve is configured to open wider and more widely when the air conditioner is operating in a non-reversing defrosting mode, with the opening changing in stages. As a result, the air conditioner can achieve non-reversing defrosting at low cost, while reducing the risk of short-circuiting and burning the electronic control. It can also ensure the heating effect of the air conditioner when the refrigerant flow rate is low, maintain the throttling effect when the air conditioner is under low load, guarantee the reliability of the compressor oil return, and ensure sufficient flow rate and cooling effect when the air conditioner is under high load.

[0142] Corresponding to the above embodiment, the present disclosure also provides a method for controlling an air conditioner. As shown in FIG1 , the air conditioner 100 may include a compressor 70, a reversing device 60, an outdoor heat exchanger 20, an electronic expansion valve 40, a refrigerant ring 50, a variable flow throttle valve 30, and an indoor heat exchanger 10, which are connected in sequence. As shown in FIG8 , the method for controlling the air conditioner according to the present disclosure embodiment includes the following steps:

[0143] S1, determining the operating condition of the air conditioner;

[0144] S2, when the air conditioner is in cooling operation, the refrigerant flow is automatically adjusted based on the variable flow throttle valve to adapt to load changes.

[0145] S3: When the air conditioner is running without reversing and defrosting, the opening of the electronic expansion valve is adjusted to increase, and the opening changes in stages.

[0146] According to one embodiment of the present disclosure, the lower limit opening of the electronic expansion valve is determined according to the outdoor ambient temperature, including: when the outdoor ambient temperature is less than or equal to a first preset outdoor temperature, setting the first opening value to the lower limit opening; when the outdoor ambient temperature is greater than the first preset outdoor temperature and less than or equal to a second preset outdoor temperature, determining the lower limit opening according to a preset linear relationship; when the outdoor ambient temperature is greater than the second preset outdoor temperature, setting the second opening value to the lower limit opening; wherein the preset linear relationship is a linear function with the outdoor ambient temperature as a variable, the first opening value is less than the minimum value of the preset linear relationship, and the maximum value of the preset linear relationship is less than the second opening value.

[0147] According to one embodiment of the present disclosure, the opening of the electronic expansion valve is adjusted to be larger, and the opening changes in stages, including: obtaining the current opening of the electronic expansion valve, and adjusting the opening of the electronic expansion valve to be larger multiple times according to the current opening, so that the opening of the electronic expansion valve changes in stages.

[0148] According to one embodiment of the present disclosure, the opening of the electronic expansion valve is adjusted to be larger multiple times according to the current opening, including: determining the target opening and the number of opening adjustments of the electronic expansion valve, and determining the adjustment step according to the current opening, the target opening and the number of opening adjustments, and adjusting the opening of the electronic expansion valve to be larger multiple times according to the adjustment step.

[0149] According to one embodiment of the present disclosure, the control method of the air conditioner also includes: obtaining at least one of the indoor ambient temperature, the outdoor ambient temperature and the outdoor heat exchanger temperature, and determining that the air conditioner does not reverse to defrost operation based on at least one of the indoor ambient temperature, the outdoor ambient temperature and the outdoor heat exchanger temperature.

[0150] According to one embodiment of the present disclosure, when it is determined that any of the following conditions are not met, the air conditioner is controlled not to switch to defrost operation: (1) the indoor ambient temperature is lower than the first preset temperature, or the outdoor ambient temperature is lower than the second preset temperature, or the sum of the indoor ambient temperature and the outdoor ambient temperature is lower than the third preset temperature; (2) the change value of the outdoor heat exchanger temperature is lower than the fourth preset temperature; (3) the outdoor ambient temperature is lower than the fifth preset temperature and the air conditioner does not enter the defrost mode within the second preset time, wherein the fifth preset temperature is higher than the second preset temperature.

[0151] According to one embodiment of the present disclosure, the control method of the air conditioner also includes: obtaining a first temperature change value of the outdoor heat exchanger and a second temperature change value of the outdoor ambient temperature within a third preset time; and determining the change value of the outdoor heat exchanger temperature based on the relationship between the first temperature change value and the second temperature change value.

[0152] According to one embodiment of the present disclosure, the control method of the air conditioner also includes: when the change value of the outdoor heat exchanger temperature is less than the sixth preset temperature, controlling the air conditioner to enter the first non-reversing defrost mode; when the change value of the outdoor heat exchanger temperature is less than the seventh preset temperature, controlling the air conditioner to enter the second non-reversing defrost mode; wherein the seventh preset temperature is less than the sixth preset temperature, and the sixth preset temperature is greater than the fourth preset temperature.

[0153] According to one embodiment of the present disclosure, when the air conditioner is operating in the first non-reversing defrost mode, the method further includes: if no change in the opening of the electronic expansion valve is detected, then when the outdoor heat exchanger temperature is greater than an eighth preset temperature or the operating time of the first non-reversing defrost mode is greater than a third preset time, controlling the air conditioner to exit the first non-reversing defrost mode; if a change in the opening of the electronic expansion valve is detected, then after a delay of a fourth preset time, determining whether the air conditioner exits the first non-reversing defrost mode based on the outdoor heat exchanger temperature.

[0154] According to one embodiment of the present disclosure, when the air conditioner is operating in the second non-reversing defrost mode, the method further includes: if no change in the opening of the electronic expansion valve is detected, then when the outdoor heat exchanger temperature is greater than a ninth preset temperature or the operating time of the second non-reversing defrost mode is greater than a fifth preset time, controlling the air conditioner to exit the second non-reversing defrost mode; if a change in the opening of the electronic expansion valve is detected, then after a delay of the sixth preset time, determining whether the air conditioner exits the second non-reversing defrost mode based on the outdoor heat exchanger temperature; wherein the ninth preset temperature is greater than the eighth preset temperature, and the fifth preset time is greater than the third preset time.

[0155] According to one embodiment of the present disclosure, the control method of the air conditioner also includes: when the air conditioner enters a first non-reversing defrost mode, controlling the compressor to operate at a first operating frequency, the outdoor fan to stop, and the speed of the indoor fan to remain unchanged; when the air conditioner enters a second non-reversing defrost mode, controlling the compressor to operate at a second operating frequency, the outdoor fan to stop, and the speed of the indoor fan to decrease according to a preset rate; wherein the first operating frequency is less than the second operating frequency.

[0156] The control method of the present disclosure is described below with reference to FIG9 .

[0157] As a specific example, the control method of the air conditioner disclosed herein may include the following steps:

[0158] S101, determining the operating condition of the air conditioner.

[0159] S102, determine whether the air conditioner is running in cooling mode. If yes, go to step S103; if not, go to step S109.

[0160] S103: Determine whether the outdoor ambient temperature is less than or equal to a first preset outdoor temperature. If yes, go to step S104; if not, go to step S105.

[0161] S104: Set the first opening value as the lower limit opening of the electronic expansion valve.

[0162] S105: Determine whether the outdoor ambient temperature is greater than a first preset outdoor temperature and less than or equal to a second preset temperature. If yes, proceed to step S106; if not, proceed to step S107.

[0163] S106: Determine the lower limit opening of the electronic expansion valve according to a preset linear relationship.

[0164] S107: Determine whether the outdoor ambient temperature is greater than a second preset temperature. If yes, execute step S108; if not, execute step S101.

[0165] S108: Set the second opening value as the lower limit opening of the electronic expansion valve.

[0166] S109: Determine whether all conditions are not satisfied. If yes, go to step S110; if not, go to step S115.

[0167] S110, determining whether the change in the outdoor heat exchanger temperature is less than a sixth preset temperature. If yes, proceed to step S111; if not, proceed to step S116.

[0168] S111, controlling the air conditioner to enter a first non-reversing defrost mode and controlling the compressor to operate at a first operating frequency, the outdoor fan to stop, and the speed of the indoor fan to remain unchanged.

[0169] S112: Determine whether the opening of the electronic expansion valve has changed. If so, go to step S113; if not, go to step S114.

[0170] S113 , when the temperature of the outdoor heat exchanger is greater than an eighth preset temperature or the operation time of the first non-reversing defrost mode is greater than a third preset time, controlling the air conditioner to exit the first non-reversing defrost mode.

[0171] S114: After a fourth preset delay time, determine whether to exit the first non-reversing defrost mode according to the outdoor heat exchanger temperature.

[0172] S115, controlling the reversal of the four-way valve to enable the air conditioner to enter a reversing defrost mode.

[0173] S116: Determine whether the change in the outdoor heat exchanger temperature is less than a seventh preset temperature. If yes, go to step S117; if not, go to step S109.

[0174] S117, controlling the air conditioner to enter a second non-reversing defrost mode and controlling the compressor to operate at a second operating frequency, the outdoor fan to stop, and the speed of the indoor fan to decrease according to a preset rate.

[0175] S118: Determine whether the opening of the electronic expansion valve has changed. If yes, go to step S119; if not, go to step S120.

[0176] S119: When the temperature of the outdoor heat exchanger is greater than a ninth preset temperature or the operation time of the second non-reversing defrost mode is greater than a fifth preset time, controlling the air conditioner to exit the second non-reversing defrost mode.

[0177] S120: After a sixth preset time delay, determine whether to exit the second non-reversing defrost mode according to the outdoor heat exchanger temperature.

[0178] It should be noted that for details not disclosed in the control method of the air conditioner in the embodiment of the present disclosure, please refer to the details disclosed in the air conditioner in the embodiment of the present disclosure, and the details will not be repeated here.

[0179] According to the control method for an air conditioner according to the embodiment of the present disclosure, the operating condition of the air conditioner is determined. When the air conditioner is in cooling operation, the refrigerant flow rate is automatically adjusted based on the variable flow throttle valve to adapt to load changes. When the air conditioner is in non-reversing defrosting operation, the opening of the electronic expansion valve is adjusted to increase, and the opening rate changes in stages. As a result, this method can achieve non-reversing defrosting at low cost and reduce the risk of short circuit and burnout of the electronic control. It can ensure the heating effect of the air conditioner when the refrigerant flow rate is low, ensure the throttling effect when the air conditioner is under low load, ensure the reliability of the compressor oil return, and ensure sufficient flow rate and cooling effect when the air conditioner is under high load.

[0180] Corresponding to the above embodiments, the present disclosure also proposes a computer-readable storage medium.

[0181] The computer-readable storage medium of the embodiment of the present disclosure stores a computer program, which implements the above-mentioned air conditioner control method when executed by a processor.

[0182] According to the computer-readable storage medium of the embodiment of the present disclosure, by executing the above-mentioned air conditioner control method, non-reversing defrosting can be achieved at low cost, and the risk of short circuit and burning of the electronic control can be reduced. The heating effect of the air conditioner can be ensured when the refrigerant flow is low, and the throttling effect can be ensured when the air conditioner is under low load, the reliability of the compressor oil return can be guaranteed, and sufficient flow can be ensured when the air conditioner is under high load to ensure the cooling effect of the air conditioner.

[0183] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic device), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0184] It should be understood that various parts of the present disclosure can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0185] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0186] Furthermore, 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 being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. Throughout the present disclosure, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0187] In this disclosure, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components, unless otherwise expressly limited. Those skilled in the art will understand the specific meanings of the above terms in this disclosure based on specific circumstances.

[0188] Although the embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. An air conditioner, comprising: The compressor, reversing device, outdoor heat exchanger, electronic expansion valve, refrigerant ring, variable flow throttle valve and indoor heat exchanger are connected in sequence, wherein: The variable flow throttle valve is configured to automatically adjust the refrigerant flow rate to adapt to load changes when the air conditioner is in cooling operation; The electronic expansion valve is configured to be opened wider when the air conditioner is not in a defrosting operation, and the opening changes in stages.

2. The air conditioner according to claim 1, wherein Also includes: The controller is configured to determine the lower limit opening of the electronic expansion valve according to the outdoor ambient temperature when the air conditioner is in cooling operation, and limit the opening of the electronic expansion valve according to the lower limit opening.

3. The air conditioner according to claim 2, wherein: The controller is further configured to: When the outdoor ambient temperature is less than or equal to a first preset outdoor temperature, setting the first opening value to the lower limit opening; When the outdoor ambient temperature is greater than a first preset outdoor temperature and less than or equal to a second preset outdoor temperature, determining the lower limit opening according to a preset linear relationship; When the outdoor ambient temperature is greater than a second preset outdoor temperature, setting the second opening value to the lower limit opening; The preset linear relationship is a linear function with the outdoor ambient temperature as a variable, the first opening value is smaller than the minimum value of the preset linear relationship, and the maximum value of the preset linear relationship is smaller than the second opening value.

4. The air conditioner according to claim 2 or 3, wherein: The controller is further configured to obtain the current opening of the electronic expansion valve when the air conditioner is not in reverse defrosting operation, and to adjust the opening of the electronic expansion valve multiple times according to the current opening so that the opening of the electronic expansion valve changes in stages.

5. The air conditioner according to claim 4, wherein The controller is further configured to determine the target opening and the number of opening adjustments of the electronic expansion valve, determine an adjustment step according to the current opening, the target opening and the number of opening adjustments, and perform multiple increasing adjustments to the opening of the electronic expansion valve according to the adjustment step.

6. The air conditioner according to claim 1, wherein Also includes: The controller is further configured to obtain at least one of the indoor ambient temperature, the outdoor ambient temperature and the outdoor heat exchanger temperature, and determine that the air conditioner is not in reverse defrosting operation based on at least one of the indoor ambient temperature, the outdoor ambient temperature and the outdoor heat exchanger temperature.

7. The air conditioner according to claim 6, wherein The controller controls the air conditioner to operate without reversing and defrosting when it determines that any of the following conditions are not met: (1) The indoor ambient temperature is lower than a first preset temperature, or the outdoor ambient temperature is lower than a second preset temperature, or the sum of the indoor ambient temperature and the outdoor ambient temperature is lower than a third preset temperature; (2) The change in the outdoor heat exchanger temperature is less than a fourth preset temperature; (3) The outdoor ambient temperature is lower than a fifth preset temperature and the air conditioner does not enter the defrost mode within a second preset time, wherein the fifth preset temperature is higher than the second preset temperature.

8. The air conditioner according to claim 7, wherein: The controller is further configured to: Obtaining a first temperature change value of the outdoor heat exchanger and a second temperature change value of the outdoor ambient temperature within a third preset time; The change value of the outdoor heat exchanger temperature is determined according to the relationship between the first temperature change value and the second temperature change value.

9. The air conditioner according to claim 7 or 8, wherein: The controller is further configured to: When the change value of the outdoor heat exchanger temperature is less than a sixth preset temperature, controlling the air conditioner to enter a first non-reversing defrost mode; When the change value of the outdoor heat exchanger temperature is less than the seventh preset temperature, the air conditioner is controlled to enter the second non-reversing defrost mode; wherein the seventh preset temperature is less than the sixth preset temperature, and the sixth preset temperature is greater than the fourth preset temperature.

10. The air conditioner according to claim 9, wherein The controller is further configured to, when the air conditioner operates in the first non-reversing defrost mode, If no change in the opening of the electronic expansion valve is detected, controlling the air conditioner to exit the first non-reversing defrost mode when the outdoor heat exchanger temperature is greater than an eighth preset temperature or the operating time of the first non-reversing defrost mode is greater than a third preset time; If the opening of the electronic expansion valve is detected to have changed, the fourth preset time is delayed and the outdoor heat exchanger temperature is determined. Whether the air conditioner exits the first non-reversing defrost mode.

11. The air conditioner according to claim 9 or 10, wherein: The controller is further configured to, when the air conditioner operates in the second non-reversing defrost mode, If no change in the opening of the electronic expansion valve is detected, controlling the air conditioner to exit the second non-reversing defrost mode when the outdoor heat exchanger temperature is greater than a ninth preset temperature or the operating time of the second non-reversing defrost mode is greater than a fifth preset time; If a change in the opening of the electronic expansion valve is detected, the air conditioner is judged whether to exit the second non-reversing defrost mode based on the outdoor heat exchanger temperature after a delay of the sixth preset time; wherein the ninth preset temperature is greater than the eighth preset temperature, and the fifth preset time is greater than the third preset time.

12. The air conditioner according to any one of claims 9 to 11, wherein: The controller is further configured to: When the air conditioner enters the first non-reversing defrost mode, the compressor is controlled to operate at a first operating frequency, the outdoor fan is stopped, and the speed of the indoor fan remains unchanged; When the air conditioner enters the second non-reversing defrost mode, the compressor is controlled to operate at a second operating frequency, the outdoor fan is stopped, and the speed of the indoor fan is reduced at a preset rate; wherein, the first operating frequency is less than the second operating frequency.

13. The air conditioner according to any one of claims 1 to 12, wherein: The electronic expansion valve is a wide-range variable gain electronic expansion valve.

14. The air conditioner according to claim 13, wherein The wide-range variable gain electronic expansion valve is further configured to change its opening degree based on the load change when the air conditioner is in heating operation.

15. The air conditioner according to claim 13 or 14, wherein: The wide-range variable gain electronic expansion valve includes a valve body, which is provided with an inlet and an outlet. A valve seat is provided at the outlet, and a valve needle is provided on the valve seat. The gap between the valve needle and the valve seat forms a throttling hole, and the valve needle adjustment section is designed at multiple angles.

16. The air conditioner according to claim 15, wherein The caliber of the valve seat ranges from 1.6 mm to 3.2 mm.

17. The air conditioner according to any one of claims 1 to 16, wherein: The variable flow throttle valve comprises: a housing, wherein a mounting channel is formed in the housing, the housing having a first medium flow port and a second medium flow port, the mounting channel communicating with the first medium flow port and the second medium flow port; a first valve seat, the first valve seat being mounted in the mounting passage, the first valve seat being formed with a first hole and a first medium flow channel adjacent to each other, the first medium flow channel communicating with the first medium flow port and the first hole, the first hole being adapted to communicate with the first medium flow channel and the second medium flow port; The first valve seat is further formed with an adjacent second hole and a second medium flow channel, the second medium flow channel is connected to the second medium flow port and the second hole, and the second hole is suitable for connecting the first medium flow port and the second medium flow channel; a first valve core, the first valve core being disposed in the first medium flow channel and being movable along the first medium flow channel to open or close the first hole; The second valve core is disposed in the second medium flow channel, and the second valve core is movable along the second medium flow channel to open or close the second hole.

18. The air conditioner according to claim 17, wherein When a medium flows into the installation channel through the first medium flow port, the medium drives the first valve core to move and close the first hole and drives the second valve core to move and open the second hole; When a medium flows into the installation channel through the second medium flow port, the medium drives the first valve core to move to open the first hole and drives the second valve core to move to close the second hole; Wherein, along the length direction of the installation channel, the first hole and the second hole are located between the first medium flow channel and the second medium flow channel.

19. The air conditioner according to claim 17 or 18, wherein: A throttling channel and a conducting channel are also formed in the shell, the throttling channel connects the first medium flow port and the second hole, and the conducting channel connects the second medium flow port and the first hole, wherein the throttling channel and / or the conducting channel are formed on the first valve seat.

20. The air conditioner according to claim 19, wherein A first communication channel is formed between the first valve seat and the housing, and the first communication channel is connected with the throttling channel and the first medium flow port; A second communication flow channel is formed between the first valve seat and the housing, and the second communication flow channel is connected with the conduction channel and the second medium flow port.

21. The air conditioner according to any one of claims 17 to 20, wherein: A first position-limiting member is provided in the first medium flow channel. The first position-limiting member is located on a side of the first valve core away from the first hole. The first position-limiting member forms a third communication flow channel connecting the first medium flow channel and the first medium flow port. The first position-limiting member is adapted to cooperate with the first valve core in limiting position. A second limiter is provided in the second medium flow channel. The second limiter is located on the side of the second valve core away from the second hole. The second limiter forms a fourth connecting flow channel connecting the second medium flow channel and the second medium flow port. The second limiter is suitable for cooperating with the second valve core in limiting position.

22. The air conditioner according to claim 21, wherein The variable flow throttle valve further includes an elastic member, which is assembled in the second medium flow channel and located between the second valve core and the second limiter, and the elastic member is connected between the second valve core and the second limiter.

23. The air conditioner according to any one of claims 17 to 22, wherein: The second valve core includes: a valve core body and a closing column connected to each other, and the closing column is used to open or close the second hole.

24. The air conditioner according to claim 23, wherein The valve core body is cylindrical, or a side wall of the valve core body is formed with at least one notch.

25. The air conditioner according to any one of claims 17 to 24, wherein: The variable flow throttle valve further comprises: a first filter element, the first filter element being installed in the installation passage and located between the first valve seat and the first medium flow port; A second filter element is installed in the installation channel and is located between the first valve seat and the second medium flow port.

26. A method for controlling an air conditioner, the air conditioner comprising: A compressor, a reversing device, an outdoor heat exchanger, an electronic expansion valve, a refrigerant ring, a variable flow throttle valve and an indoor heat exchanger are connected in sequence, and the method includes: determining an operating condition of the air conditioner; When the air conditioner is in cooling operation, the refrigerant flow rate is automatically adjusted based on the variable flow throttle valve to adapt to load changes; When the air conditioner is in non-reversing defrosting operation, the electronic expansion valve is adjusted to increase its opening, and the opening changes in stages.

27. The control method according to claim 26, wherein: Also includes: The lower limit opening of the electronic expansion valve is determined according to the outdoor ambient temperature, and the opening of the electronic expansion valve is restricted according to the lower limit opening.

28. The control method according to claim 27, wherein: Determining the lower limit opening of the electronic expansion valve according to the outdoor ambient temperature includes: When the outdoor ambient temperature is less than or equal to a first preset outdoor temperature, setting the first opening value to the lower limit opening; When the outdoor ambient temperature is greater than a first preset outdoor temperature and less than or equal to a second preset outdoor temperature, determining the lower limit opening according to a preset linear relationship; When the outdoor ambient temperature is greater than a second preset outdoor temperature, setting the second opening value to the lower limit opening; The preset linear relationship is a linear function with the outdoor ambient temperature as a variable, the first opening value is smaller than the minimum value of the preset linear relationship, and the maximum value of the preset linear relationship is smaller than the second opening value.

29. The control method according to claim 27 or 28, wherein: The electronic expansion valve is adjusted to increase its opening, and the opening changes in stages, including: The current opening of the electronic expansion valve is obtained, and the opening of the electronic expansion valve is adjusted to increase multiple times according to the current opening, so that the opening of the electronic expansion valve changes in stages.

30. The control method according to claim 29, wherein: The opening of the electronic expansion valve is adjusted to increase multiple times according to the current opening, including: The target opening and the number of opening adjustments of the electronic expansion valve are determined, and an adjustment step is determined according to the current opening, the target opening and the number of opening adjustments, and the opening of the electronic expansion valve is adjusted to increase multiple times according to the adjustment step.

31. The control method according to any one of claims 26 to 30, wherein: Also includes: At least one of an indoor ambient temperature, an outdoor ambient temperature, and an outdoor heat exchanger temperature is acquired, and non-reversing defrosting operation of the air conditioner is determined based on at least one of the indoor ambient temperature, the outdoor ambient temperature, and the outdoor heat exchanger temperature.

32. The control method according to claim 31, wherein: When it is determined that any of the following conditions is not met, the air conditioner is controlled to operate without reversing and defrosting: (1) The indoor ambient temperature is lower than a first preset temperature, or the outdoor ambient temperature is lower than a second preset temperature, or the sum of the indoor ambient temperature and the outdoor ambient temperature is lower than a third preset temperature; (2) The change in the outdoor heat exchanger temperature is less than a fourth preset temperature; (3) The outdoor ambient temperature is lower than a fifth preset temperature and the air conditioner does not enter the defrost mode within a second preset time, wherein the fifth preset temperature is higher than the second preset temperature.

33. The control method according to claim 32, wherein: Also includes: Obtaining a first temperature change value of the outdoor heat exchanger and a second temperature change value of the outdoor ambient temperature within a third preset time; The change value of the outdoor heat exchanger temperature is determined according to the relationship between the first temperature change value and the second temperature change value.

34. The control method according to claim 32 or 33, wherein: Also includes: When the change value of the outdoor heat exchanger temperature is less than a sixth preset temperature, controlling the air conditioner to enter a first non-reversing defrost mode; When the change value of the outdoor heat exchanger temperature is less than the seventh preset temperature, the air conditioner is controlled to enter the second non-reversing defrost mode; wherein the seventh preset temperature is less than the sixth preset temperature, and the sixth preset temperature is greater than the fourth preset temperature.

35. The control method according to claim 34, wherein: When the air conditioner operates in the first non-reversing defrost mode, the method further includes: If no change in the opening of the electronic expansion valve is detected, controlling the air conditioner to exit the first non-reversing defrost mode when the outdoor heat exchanger temperature is greater than an eighth preset temperature or the operating time of the first non-reversing defrost mode is greater than a third preset time; If a change in the opening of the electronic expansion valve is detected, after a fourth preset time delay, it is determined according to the temperature of the outdoor heat exchanger whether the air conditioner exits the first non-reversing defrost mode.

36. The control method according to claim 34 or 35, wherein: When the air conditioner operates in the second non-reversing defrost mode, the method further includes: If no change in the opening of the electronic expansion valve is detected, controlling the air conditioner to exit the second non-reversing defrost mode when the outdoor heat exchanger temperature is greater than a ninth preset temperature or the operating time of the second non-reversing defrost mode is greater than a fifth preset time; If a change in the opening of the electronic expansion valve is detected, the air conditioner is judged whether to exit the second non-reversing defrost mode based on the outdoor heat exchanger temperature after a delay of the sixth preset time; wherein the ninth preset temperature is greater than the eighth preset temperature, and the fifth preset time is greater than the third preset time.

37. The control method according to any one of claims 34 to 36, wherein: Also includes: When the air conditioner enters the first non-reversing defrost mode, the compressor is controlled to operate at a first operating frequency, the outdoor fan is stopped, and the speed of the indoor fan remains unchanged; When the air conditioner enters the second non-reversing defrost mode, the compressor is controlled to operate at a second operating frequency, the outdoor fan is stopped, and the speed of the indoor fan is reduced at a preset rate; wherein, the first operating frequency is less than the second operating frequency.

38. A computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the method for controlling an air conditioner according to any one of claims 26 to 37 is implemented.

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