Control method of air conditioner

Abstract

The invention relates to the field of air conditioners, particularly provides a control method of an air conditioner, and aims to solve the problem of poor heating effect of an existing air conditioner under an ultralow-temperature heating working condition. In order to achieve the purpose, the air conditioner comprises a filling cavity and a first valve body, an outlet of the filling cavity is connected with an air suction port of a compressor of the air conditioner, the first valve body is used for enabling the outlet to communicate with the air suction port when the first valve body is opened and enabling the outlet to be blocked from the air suction port when the first valve body is closed, and the control method comprises the steps that under the heating working condition, the outdoor environment temperature is obtained; when the outdoor environment temperature is smaller than a preset ultralow temperature threshold value, the exhaust pressure of the compressor is obtained; and when the exhaust pressure reaches the preset target exhaust pressure, the first valve body is controlled to be opened, so that the frequency of the compressor continues to be increased, it is ensured that the air conditioner can still keep high heating efficiency even under the ultralow temperature condition, and the requirement for indoor comfort is met.

Description

Technical Field

[0001] The present invention relates to the field of air conditioners, and specifically provides a control method for an air conditioner. Background Art

[0002] As an important facility for indoor temperature regulation, air conditioning systems are widely used in residential, commercial, and industrial fields. With global climate change and increasing energy efficiency requirements, the energy efficiency and adaptability of air conditioning systems have become the focus of research and development. Especially in the heating mode, the performance of air conditioning systems is significantly affected by the outdoor ambient temperature.

[0003] In cold environments, the compressor, as the core component of an air conditioning system, its efficiency and output capacity are crucial for the heating performance of the entire system. The compressor compresses the refrigerant, raises its temperature, and transfers the heat to the indoor environment. However, under extremely low temperature conditions, even when the exhaust pressure reaches the target value, due to system limitations, the compressor cannot correspondingly increase its operating frequency, thus reducing the heating effect of the entire system.

[0004] Existing air conditioning systems do not fully consider the impact of ultra-low temperature environments on compressor performance during design. Traditional control strategies and hardware designs are insufficient to maintain efficient heating performance under extreme weather conditions, which may lead to a decline in user experience, increased energy consumption, and may pose risks to the long-term stability of the system.

[0005] Correspondingly, there is a need in the art for a new control method for air conditioners to solve the above problems. Summary of the Invention

[0006] The present invention aims to solve the above technical problems, that is, to solve the problem of poor heating effect of existing air conditioners under ultra-low temperature heating conditions.

[0007] In a first aspect, the present invention provides a control method for an air conditioner, characterized in that the air conditioner includes a charging cavity and a first valve body. The outlet of the charging cavity is connected to the suction port of the compressor of the air conditioner. The first valve body is used to communicate the outlet with the suction port when opened and block the outlet from the suction port when closed. The control method includes: under a heating condition, obtaining the outdoor ambient temperature; when the outdoor ambient temperature is less than a preset ultra-low temperature threshold, obtaining the exhaust pressure of the compressor; when the exhaust pressure reaches a preset target exhaust pressure, controlling the first valve body to open so that the frequency of the compressor can continue to increase.

[0008] In an alternative technical solution of the above control method, the air conditioner further includes a temperature sensor for detecting the real-time temperature at the inlet of the indoor heat exchanger or the outlet of the outdoor heat exchanger. After "controlling the first valve body to open", the control method further includes: when the exhaust pressure is greater than the target exhaust pressure, comparing the real-time temperature with a preset temperature; and based on the comparison result, determining whether to control the first valve body to close.

[0009] In an alternative technical solution of the above control method, the step of "determining whether the first valve body is closed based on the comparison result" further includes: if the real-time temperature is greater than or equal to the preset temperature, controlling the first valve body to close.

[0010] In an alternative technical solution of the above control method, the control method further includes: when the exhaust pressure is greater than the target exhaust pressure, if the exhaust pressure rises to a preset target protection pressure, controlling the first valve body to close.

[0011] In an alternative technical solution of the above control method, the charging cavity is provided with an inlet, and the refrigerant circulation pipe between the compressor and the outdoor heat exchanger is connected to the inlet. The air conditioner further includes a second valve body for communicating the inlet with the refrigerant circulation pipe when opened and blocking the inlet from the refrigerant circulation pipe when closed. The control method further includes: when the outdoor ambient temperature is greater than or equal to the ultra-low temperature threshold, respectively adjusting the opening degrees of the first valve body and the second valve body; and when the pressure in the charging cavity reaches a preset pressure, controlling both the first valve body and the second valve body to close.

[0012] In an alternative technical solution of the above control method, the charging cavity is provided with an inlet, and the refrigerant circulation pipe between the compressor and the outdoor heat exchanger is connected to the inlet. The air conditioner further includes a second valve body for communicating the inlet with the refrigerant circulation pipe when opened and blocking the inlet from the refrigerant circulation pipe when closed. At the same time as, before, or after "controlling the first valve body to open", the control method further includes: controlling the second valve body to open.

[0013] In an alternative technical solution of the above control method, the charging cavity is provided with an inlet, and the refrigerant circulation pipe between the compressor and the outdoor heat exchanger is connected to the inlet. The air conditioner further includes a second valve body for communicating the inlet with the refrigerant circulation pipe when opened and blocking the inlet from the refrigerant circulation pipe when closed. At the same time as, before, or after "controlling the first valve body to close", the control method further includes: controlling the second valve body to close.

[0014] In an alternative technical solution of the above control method, the air conditioner further includes a temperature sensor for detecting the real-time temperature at the inlet of the indoor heat exchanger or the outlet of the outdoor heat exchanger; the step of "controlling the first valve body to open when the exhaust pressure reaches the preset target exhaust pressure" further includes: when the exhaust pressure reaches the preset target exhaust pressure, if the real-time temperature is less than the preset temperature, controlling the first valve body to open.

[0015] In an alternative technical solution of the above control method, after the step of "controlling the first valve body to open", the control method further includes: if the real-time temperature is greater than or equal to the preset temperature, controlling the frequency of the compressor to remain unchanged; and / or the control method further includes: when the exhaust pressure reaches the preset target exhaust pressure, if the real-time temperature is greater than or equal to the preset temperature, controlling the first valve body to close.

[0016] In an alternative technical solution of the above control method, the control method further includes: when the exhaust pressure is less than the target exhaust pressure, controlling the frequency of the compressor to increase.

[0017] When the outdoor ambient temperature is less than the preset ultra-low temperature threshold, due to the extremely low external temperature, the evaporation process of the refrigerant in the outdoor heat exchanger will be affected, the heat transfer efficiency will decrease, and thus the heating capacity of the entire system will be reduced. Since the preset target exhaust pressure of the system is designed based on normal heating conditions, even if the exhaust pressure reaches the target exhaust pressure, the load of the compressor (the flow rate and pressure of the refrigerant) will not increase. Due to the lack of sufficient load, it is impossible to control the frequency of the compressor to increase, and it is impossible to ensure sufficient heating efficiency in such an ultra-low temperature environment. Therefore, after the outdoor ambient temperature is less than the ultra-low temperature threshold, if it is detected that the exhaust pressure reaches the preset target exhaust pressure, the present invention will control the first valve body to open, so that more refrigerant flows into the compressor, ensuring that the compressor can handle a larger flow rate of refrigerant. In this case, the frequency of the compressor can be effectively controlled to increase, so as to ensure that the outdoor heat exchanger can absorb more heat from the outdoor low-temperature air, and the indoor heating can be effectively achieved even in very low temperatures. Generally speaking, the above control method ensures that the air conditioner can still maintain a high heating efficiency even under ultra-low temperature conditions, meeting the requirements of indoor comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The following describes the preferred embodiments of the present invention with reference to the accompanying drawings, in which:

[0019] Figure 1 is a schematic structural diagram of the air conditioner of the present invention;

[0020] Figure 2 is the main flowchart of the control method of the air conditioner of the present invention;

[0021] Figure 3 It is a possible logic diagram of the control method of the air conditioner of the present invention.

[0022] Description of the reference numerals in the drawings:

[0023] 1 - Refrigerant circulation pipe; 11 - First charging branch pipe; 12 - Second charging branch pipe; 2 - Compressor; 3 - Outdoor heat exchanger; 4 - Throttling device; 5 - Indoor heat exchanger; 6 - Charging cavity; 7 - First valve body; 8 - Second valve body; 9 - First pressure sensor. Detailed implementation manners

[0024] The preferred implementation manners of the present invention will be described below with reference to the drawings. Those skilled in the art should understand that these implementation manners are only used to explain the technical principle of the present invention and are not intended to limit the protection scope of the present invention. Those skilled in the art can adjust them according to needs to adapt to specific application scenarios, and these do not deviate from the principle of the present invention and are all within the protection scope of the present invention.

[0025] In order to solve the problem of poor heating effect of the existing air conditioner under ultra - low temperature heating conditions. The present invention provides a control method for an air conditioner, as Figure 1 shown, the air conditioner includes a refrigerant circulation pipe 1, on which a compressor 2, an indoor heat exchanger 5, a throttling device 4 and an outdoor heat exchanger 3 are sequentially arranged. Among them, the throttling device 4 is used for throttling and pressure reduction, and specifically can be a throttle valve or a capillary tube, etc. The air conditioner of the present invention further includes a charging cavity 6 and a first valve body 7. The outlet of the charging cavity 6 is connected to the suction port of the compressor 2, and the first valve body 7 is used to connect the outlet and the suction port when opened and block the connection between the outlet and the suction port when closed. The charging cavity 6 is used to fill the refrigerant. The air conditioner of the present invention further includes a first pressure sensor 9, and the first pressure sensor 9 is arranged on one side of the exhaust port of the compressor 2, such as on the refrigerant circulation pipe 1 on one side of the exhaust port of the compressor 2, or directly arranged on the exhaust port of the compressor 2, etc. As long as the first pressure sensor 9 can obtain the exhaust pressure of the compressor 2, the adjustment of its specific installation position does not deviate from the principle of the present invention and is all within the protection scope of the present invention.

[0026] The heating process of the air conditioner will be briefly introduced below. The compressor 2 sucks in the low - temperature and low - pressure gaseous refrigerant and compresses it into a high - temperature and high - pressure gas. The high - temperature and high - pressure refrigerant gas compressed by the compressor 2 enters the indoor heat exchanger 5 (used as a condenser). In the indoor heat exchanger 5, the refrigerant gas releases its heat by exchanging heat with the indoor air and becomes a high - pressure liquid refrigerant. The high - pressure liquid refrigerant enters the outdoor heat exchanger 3 after being depressurized by the throttling device 4. In the outdoor heat exchanger 3, the refrigerant liquid exchanges heat with the outdoor environment, absorbs heat and evaporates into a low - temperature and low - pressure gas, and so on in a cycle.

[0027] As a first possible implementation manner, the charging cavity 6 is provided with an inlet, and the refrigerant circulation pipe 1 between the compressor 2 and the outdoor heat exchanger 3 is connected to the inlet. The air conditioner further includes a second valve body 8, and the second valve body 8 is used to connect the inlet to the refrigerant circulation pipe 1 when it is opened and block the inlet from the refrigerant circulation pipe 1 when it is closed. There are various specific implementation manners as described above. For example, the air conditioner further includes a first charging branch pipe 11 and a second charging branch pipe 12. One end of the first charging branch pipe 11 is connected to the outlet of the charging cavity 6, and the other end is connected to the refrigerant circulation pipe 1 on the suction port side of the compressor 2. Of course, the other end can also be directly connected to the suction port of the compressor 2. One end of the second charging branch pipe 12 is connected to the inlet of the charging cavity 6, and the refrigerant circulation pipe 1 between the first charging branch pipe 11 and the outdoor heat exchanger 3 is connected to the other end of the second charging branch pipe 12. The first valve body 7 is arranged on the first charging branch pipe 11, and the second valve body 8 is arranged on the second charging branch pipe 12. Among them, the first valve body 7 can be an electromagnetic valve or a flow regulating valve, etc., and the second valve body 8 can be an electromagnetic valve or a flow regulating valve, etc. As long as both the first valve body 7 and the second valve body 8 can achieve opening and closing, the specific structural forms of the first valve body 7 and the second valve body 8 can be adjusted. Of course, the above specific implementation manners are not restrictive. For example, the outlet of the charging cavity 6 is directly connected to the suction port of the compressor 2, the inlet of the charging cavity 6 is directly connected to the refrigerant circulation pipe 1, the first valve body 7 is arranged on the outlet of the charging cavity 6, and the second valve body 8 is arranged on the inlet of the charging cavity 6, etc. As long as it can be achieved that the first valve body 7 connects the outlet of the charging cavity 6 to the suction port of the compressor 2 when it is opened and blocks the outlet of the charging cavity 6 from the suction port of the compressor 2 when it is closed. And / or as long as it can be achieved that the second valve body 8 connects the inlet of the charging cavity 6 to the refrigerant circulation pipe 1 when it is opened and blocks the inlet of the charging cavity 6 from the refrigerant circulation pipe 1 when it is closed. The adjustments of these specific structural forms do not deviate from the principle of the present invention and are all within the protection scope of the present invention.

[0028] As an alternative implementation manner, the setting of the second valve body 8 and the second charging pipe can be omitted. In this case, the charging cavity 6 may not be provided with an inlet. The outlet of the charging cavity 6 is directly or indirectly connected to the suction port of the compressor 2 through the first charging pipe, and the first valve body 7 can be arranged on the first charging pipe. Further, an air inlet can be provided on the charging cavity 6, and a one-way valve is arranged on the air inlet. The one-way valve is arranged to prevent the gas in the charging cavity 6 from flowing out, so as to improve the efficiency of injecting the refrigerant in the charging cavity 6 into the compressor 2.

[0029] As a possible implementation, the air conditioner of the present invention further includes a first temperature sensor (not shown in the figure), and the first temperature sensor is used to obtain the outdoor ambient temperature. Among them, the first temperature sensor can be arranged at the air outlet of the outdoor unit of the air conditioner, or on the outer shell of the outdoor unit, etc. As long as the first temperature sensor can obtain the outdoor ambient temperature, its specific setting method can be adjusted, and these adjustments do not deviate from the principle of the present invention and are all within the protection scope of the present invention.

[0030] As a possible implementation, the air conditioner of the present invention further includes a second temperature sensor (not shown in the figure), and the second temperature sensor is used to detect the real-time temperature at the inlet of the indoor heat exchanger 5 or the outlet of the outdoor heat exchanger 3. For example, the second temperature sensor is arranged on the inlet of the indoor heat exchanger 5, or on the refrigerant circulation pipe 1 on the inlet side of the indoor heat exchanger 5, or on the outlet of the outdoor heat exchanger 3, or on the refrigerant circulation pipe 1 on the outlet side of the outdoor heat exchanger 3. As long as the real-time temperature at the inlet of the indoor heat exchanger 5 or the outlet of the outdoor heat exchanger 3 can be obtained, its specific setting method can be adjusted, and these adjustments do not deviate from the principle of the present invention and are all within the protection scope of the present invention.

[0031] As a possible implementation, a second pressure sensor is provided on the charging cavity, and the second pressure sensor is used to detect the pressure in the charging cavity.

[0032] Next, the control method of the air conditioner of the present invention will be introduced. As Figure 2 shown, the control method of the air conditioner of the present invention includes the following steps:

[0033] Step S100: In the heating mode, obtain the outdoor ambient temperature.

[0034] The present invention does not limit the entry timing of the heating mode. For example, after the user sends a heating command through the terminal or the remote control, the air conditioner enters the heating mode. Or the air conditioner judges whether to enter the heating mode based on outdoor environmental parameters, etc. For example, when the outdoor ambient temperature is less than the preset ambient temperature, the air conditioner enters the heating mode, etc. Among them, the preset ambient temperature can be determined based on experiments or experience. For example, the preset ambient temperature is 10°C.

[0035] The outdoor ambient temperature of the present invention can be obtained through the first temperature sensor. Of course, this is not restrictive. For example, the local outdoor ambient temperature can also be obtained through the cloud server. The present invention does not limit the specific acquisition method of the outdoor ambient temperature. As long as the outdoor ambient temperature can be obtained, its acquisition method can be adjusted, and these adjustments do not deviate from the principle of the present invention and are all within the protection scope of the present invention.

[0036] Step S200: When the outdoor ambient temperature is less than a preset ultra-low temperature threshold, obtain the discharge pressure of the compressor.

[0037] When the outdoor ambient temperature is less than the preset ultra-low temperature threshold, it proves that the outdoor ambient temperature has reached ultra-low temperature, and the air conditioner can no longer ensure efficient heating performance. The ultra-low temperature threshold can be set based on the design specifications of the air conditioner, the refrigerant used, the operating range of the system, and the expected performance in a specific environment. For example, the ultra-low temperature threshold is -10°C, -5°C, etc.

[0038] Step S300: When the discharge pressure reaches the preset target discharge pressure, control the first valve body to open so that the frequency of the compressor can continue to increase.

[0039] Possibly, the preset target discharge pressure is the discharge pressure value that the compressor of the air conditioning system should reach under the heating condition when the outdoor ambient temperature is greater than or equal to the ultra-low temperature threshold. For example, it can find out the required discharge pressure under the heating condition when the outdoor ambient temperature is greater than or equal to the ultra-low temperature threshold according to the compressor performance table provided by the manufacturer or the performance curve of the compressor under different working conditions. Or the target discharge pressure can be optimized based on test data and actual operation feedback under the heating condition when the outdoor ambient temperature is greater than or equal to the ultra-low temperature threshold to obtain the best target discharge pressure and use it as the preset target discharge pressure.

[0040] In addition, it should also be noted that the target discharge pressure of the present invention can be a specific value or a range value. When the target discharge pressure is a specific value, when the discharge pressure reaches the preset target discharge pressure, it means that the discharge pressure is equal to the target discharge pressure. When the target discharge pressure is a range value, it means that the discharge pressure is within that range value.

[0041] When the outdoor ambient temperature is lower than the preset ultra-low temperature threshold, due to the extremely low external temperature, the evaporation process of the refrigerant in the outdoor heat exchanger will be affected, resulting in a decrease in heat transfer efficiency and thus reducing the heating capacity of the entire system. Since the target discharge pressure preset by the system is designed based on normal heating conditions, even if the discharge pressure reaches the target discharge pressure, the load of the compressor (the flow rate and pressure of the refrigerant) will not increase. Due to insufficient load, the frequency increase of the compressor cannot be controlled, and it is impossible to ensure sufficient heating efficiency in such an ultra-low temperature environment. Therefore, after the outdoor ambient temperature is lower than the ultra-low temperature threshold, if it is detected that the discharge pressure reaches the preset target discharge pressure, the present invention controls the opening of the first valve body, so that more refrigerant flows into the compressor, ensuring that the compressor can handle a larger flow rate of refrigerant. In this case, the frequency increase of the compressor can be effectively controlled, thereby ensuring that the outdoor heat exchanger can absorb more heat from the outdoor low-temperature air and effectively achieve indoor heating even in very low temperatures. Generally speaking, the above control method ensures that the air conditioner can still maintain a high heating efficiency even under ultra-low temperature conditions, meeting the requirements of indoor comfort.

[0042] Further, after step S300, the control method of the present invention further includes: when the discharge pressure is greater than the target discharge pressure, comparing the real-time temperature with the preset temperature; based on the comparison result, determining whether to control the first valve body to close. The real-time temperature is obtained by the second temperature sensor. The preset temperature can be obtained based on experiments, or determined based on the sizes, types of the indoor heat exchanger and the outdoor heat exchanger, and their theoretical optimal temperature ranges during operation, etc.

[0043] Possibly, if the real-time temperature is greater than or equal to the preset temperature, control the first valve body to close. If the real-time temperature is less than the preset temperature, control the first valve body to continue to maintain the open state. After the first valve body is opened, since more refrigerant flows into the compressor, the frequency increase of the compressor can be ensured. In this case, the discharge pressure will rise to be greater than the target discharge pressure, and the real-time temperature will also rise. Closing the first valve body when the real-time temperature rises to be greater than or equal to the preset temperature can prevent overheating, thereby saving energy and reducing operating costs, avoiding the long-term operation of the compressor in a high-pressure environment, and prolonging the service life of the compressor.

[0044] Further, when the discharge pressure is greater than the target discharge pressure, if the discharge pressure rises to the preset target protection pressure, control the first valve body to close. That is to say, after the discharge pressure rises to the preset target protection pressure, even if the real-time temperature is still less than the preset temperature, control the first valve body to close. The target protection pressure is a set safety threshold. When the discharge pressure rises to be close to or equal to this target protection pressure, the first valve body is closed to reduce the load of the compressor and prevent equipment failure or damage due to excessive pressure.

[0045] As a possible implementation manner, step S300 further includes: when the exhaust pressure reaches a preset target exhaust pressure, the first valve body is controlled to open only if the real-time temperature is lower than the preset temperature. That is to say, if the real-time temperature is greater than or equal to the preset temperature, the first valve body is controlled to close.

[0046] Under the ultra-low temperature heating condition, the indoor temperature may change due to factors such as personnel flow and opening / closing of doors and windows. When the temperature difference between indoor and outdoor is small, the real-time temperature may be greater than or equal to the preset temperature. In addition, other operating parameters of the air conditioner will also affect the change of the real-time temperature, such as the opening degree of the throttle valve, etc. Or when a heating device is provided at the outdoor heat exchanger, if the heating device is turned on, the real-time temperature may also be greater than or equal to the preset temperature. Therefore, when the exhaust pressure reaches the preset target exhaust pressure, the present invention still compares the real-time temperature with the preset temperature, and controls the first valve body to open only when the real-time temperature is lower than the preset temperature, which can avoid waste of energy and achieve precise control.

[0047] As a possible implementation manner, after step S300, the control method of the present invention further includes that if the real-time temperature is greater than or equal to the preset temperature, the frequency of the compressor is controlled to remain unchanged. Thereby, the continuous increase of the real-time temperature can be avoided, overheating can be prevented, energy can be saved, and the operating cost can be reduced. It can be understood that in this case, the first valve body can be in an open state or a closed state.

[0048] As a possible implementation manner, the control method of the present invention further includes: when the exhaust pressure is lower than the target exhaust pressure, the frequency of the compressor is controlled to increase. Since when the exhaust pressure is lower than the target exhaust pressure, usually the real-time temperature will be lower than the preset temperature, by controlling the increase of the frequency of the compressor, the real-time temperature and the exhaust pressure can be increased. When the exhaust pressure reaches the preset target exhaust pressure, step S300 is executed.

[0049] The above control method can be a method based on the structure of omitting the second valve body and the second charging pipe and not providing an inlet for the charging cavity. On the basis of not omitting the structure of the second valve body and the second charging pipe, while, before or after controlling the first valve body to open, the second valve body is also controlled to open. While, before or after controlling the first valve body to close, the second valve body is also controlled to close. Further, the flow rate and speed of the refrigerant charging can be adjusted by adjusting the opening degrees of the first valve body and the second valve body. For example, under the condition that the first valve body and the second valve body have the same specifications, the opening degree of the second valve body is controlled to be smaller than that of the first valve body, so as to establish a pressure difference and accelerate the injection of the refrigerant.

[0050] The above control method is for the ultra-low temperature heating condition. Under the normal temperature heating condition, the target exhaust pressure is to meet the heating demand. At this time, the refrigerant can be recovered into the charging cavity, which can reduce the burden on the compressor, lower the energy consumption, and avoid the system pressure being too high to affect the performance of the heat exchanger. The following introduces the recovery method.

[0051] Under the heating condition, if the outdoor ambient temperature is greater than or equal to the ultra-low temperature threshold, the opening degrees of the first valve body and the second valve body are respectively adjusted; when the pressure in the charging cavity reaches the preset pressure, the first valve body and the second valve body are both controlled to close.

[0052] Specifically, the pressure in the charging cavity can be detected by a second pressure sensor. The opening degree of the first valve body can be controlled to be less than that of the second valve body. For example, the first valve body is slightly opened or maintained at a certain opening degree, and the opening degree of the second valve body is increased to allow more refrigerant to flow into the charging cavity to control the amount of refrigerant entering the charging cavity. When the pressure approaches the preset pressure, the opening degree of the first valve body can be increased to slow down the rate of refrigerant entering the charging cavity, and at the same time, the opening degree of the second valve body can be further adjusted adaptively to stabilize the pressure rising speed. When the pressure reaches the preset pressure (equal to the specific value of the preset pressure or within the range value of the preset pressure), the first valve body and the second valve body are controlled to close to maintain the current pressure. Of course, the above control method is only exemplary, and as long as the pressure can be raised to the preset pressure, the control method can be adjusted.

[0053] Of course, the second pressure sensor can also not be provided. Both the second valve body and the first valve body are flow regulating valves, and the pressure is judged whether it reaches the preset pressure based on the gas flow rates flowing through the first valve body and the second valve body. These adjustments do not deviate from the principle of the present invention and are all within the protection scope of the present invention.

[0054] Further, when the outdoor ambient temperature is greater than or equal to the ultra-low temperature threshold, it can be first judged whether the pressure in the charging cavity has reached the preset pressure. If so, there is no need to adjust the opening degrees of the first valve body and the second valve body.

[0055] As a possible implementation manner, as Figure 3 shown, the control method of the air conditioner of the present invention includes the following steps:

[0056] Step S401: Under the heating condition, obtain the outdoor ambient temperature.

[0057] Step S402: Judge whether the outdoor ambient temperature is less than the preset ultra-low temperature threshold? If so, execute step S403; if not, execute step S411.

[0058] Step S403: Obtain the exhaust pressure of the compressor.

[0059] Step S404: Determine whether the exhaust pressure has reached the target exhaust pressure? If yes, execute step S406; if not, execute step S405.

[0060] Step S405: Control the frequency of the compressor to increase.

[0061] Step S406: Determine whether the real-time temperature is less than the preset temperature? If yes, execute step S408; if not, execute step S407.

[0062] Step S407: Control the frequency of the compressor to remain unchanged, and then execute step S410.

[0063] Step S408: Control the first valve body and the second valve body to open, and then execute step S409 and return to execute step S406.

[0064] Step S409: When the exhaust pressure is greater than the target exhaust pressure, determine whether the exhaust pressure has increased to the target protection pressure? If yes, execute step S410.

[0065] Step S410: Control the first valve body and the second valve body to close.

[0066] Step S411: Determine whether the pressure in the charging cavity has reached the preset pressure? If not, execute step S412; if yes, execute step S413.

[0067] Step S412: Adjust the opening degrees of the first valve body and the second valve body respectively to make the pressure reach the preset pressure.

[0068] Step S413: Control the first valve body and the second valve body to be in the closed state.

[0069] Those skilled in the art can understand that the above air conditioner includes some well-known structures, such as a processor, a controller, a memory, etc. Among them, the memory includes but is not limited to random access memory, flash memory, read-only memory, programmable read-only memory, volatile memory, non-volatile memory, serial memory, parallel memory or registers, etc. The processor includes but is not limited to CPLD / FPGA, DSP, ARM processor, MIPS processor, etc. In order not to unnecessarily obscure the embodiments of the present disclosure, these well-known structures are not shown in the drawings.

[0070] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

Claims

1. A control method for an air conditioner, characterized in that, The air conditioner includes a charging cavity and a first valve body. The outlet of the charging cavity is connected to the suction port of the compressor of the air conditioner. The first valve body is used to communicate the outlet with the suction port when it is opened and block the outlet from the suction port when it is closed. The control method includes: Under the heating condition, obtain the outdoor ambient temperature; When the outdoor ambient temperature is less than a preset ultra-low temperature threshold, obtain the discharge pressure of the compressor; When the discharge pressure reaches a preset target discharge pressure, control the first valve body to open so that the frequency of the compressor can continue to increase.

2. The control method of the air conditioner according to claim 1, wherein The air conditioner further includes a temperature sensor, which is used to detect the real-time temperature at the inlet of the indoor heat exchanger or the outlet of the outdoor heat exchanger; After "control the first valve body to open", the control method further includes: When the discharge pressure is greater than the target discharge pressure, compare the real-time temperature with the preset temperature; Based on the comparison result, judge whether to control the first valve body to close.

3. The control method of the air conditioner according to claim 2, wherein: The step of "judging whether the first valve body is closed based on the comparison result" further includes: If the real-time temperature is greater than or equal to the preset temperature, control the first valve body to close.

4. The control method of the air conditioner according to claim 2 or 3, wherein: The control method further includes: When the discharge pressure is greater than the target discharge pressure, if the discharge pressure rises to a preset target protection pressure, control the first valve body to close.

5. The control method of the air conditioner according to claim 1, wherein: The charging cavity is provided with an inlet, and the refrigerant circulation pipe between the compressor and the outdoor heat exchanger is connected to the inlet. The air conditioner further includes a second valve body, which is used to communicate the inlet with the refrigerant circulation pipe when it is opened and block the inlet from the refrigerant circulation pipe when it is closed. The control method further includes: When the outdoor ambient temperature is greater than or equal to the ultra-low temperature threshold, adjust the opening degrees of the first valve body and the second valve body respectively; When the pressure in the charging cavity reaches a preset pressure, control both the first valve body and the second valve body to close.

6. The control method of the air conditioner according to claim 4, wherein: The charging cavity is provided with an inlet, and the refrigerant circulation pipe between the compressor and the outdoor heat exchanger is connected to the inlet. The air conditioner further includes a second valve body, which is used to communicate the inlet with the refrigerant circulation pipe when it is opened and block the inlet from the refrigerant circulation pipe when it is closed; When, before or after "control the first valve body to open", the control method further includes: Control the second valve body to open.

7. The control method of the air conditioner according to claim 4, wherein: The charging cavity is provided with an inlet, and the refrigerant circulation pipe between the compressor and the outdoor heat exchanger is connected to the inlet. The air conditioner further includes a second valve body, which is used to connect the inlet to the refrigerant circulation pipe when it is opened and block the connection between the inlet and the refrigerant circulation pipe when it is closed; Simultaneously with, before or after "controlling the first valve body to close", the control method further includes: Controlling the second valve body to close.

8. The control method of the air conditioner according to claim 1, wherein The air conditioner further includes a temperature sensor, which is used to detect the real-time temperature at the inlet of the indoor heat exchanger or the outlet of the outdoor heat exchanger; The step of "controlling the first valve body to open when the exhaust pressure reaches the preset target exhaust pressure" further includes: When the exhaust pressure reaches the preset target exhaust pressure, if the real-time temperature is less than the preset temperature, controlling the first valve body to open.

9. The control method of the air conditioner according to claim 8, wherein After the step of "controlling the first valve body to open", the control method further includes: If the real-time temperature is greater than or equal to the preset temperature, controlling the frequency of the compressor to remain unchanged; and / or The control method further includes: When the exhaust pressure reaches the preset target exhaust pressure, if the real-time temperature is greater than or equal to the preset temperature, controlling the first valve body to close.

10. The control method of the air conditioner according to claim 1, wherein The control method further includes: When the exhaust pressure is less than the target exhaust pressure, controlling the frequency of the compressor to increase.

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