A defrosting control method, device, storage medium and air conditioner for an air conditioner

Abstract

The present invention discloses a defrosting control method, device, storage medium and air conditioner for an air conditioner. The defrosting control method of the air conditioner is applied to an automotive air conditioner. The air conditioner includes an outdoor unit and an indoor unit. The outdoor unit has outdoor unit components, and the outdoor unit components include a compressor. The indoor unit has indoor unit components. The defrosting control method includes: when the air conditioner enters the defrosting mode, in the initial stage of defrosting in the defrosting mode, controlling the operating states of the outdoor unit and the indoor unit to reduce the ratio of the discharge pressure to the suction pressure of the compressor; in the middle stage of defrosting, controlling the operating states of the outdoor unit and the indoor unit to defrost the outdoor unit; in the final stage of defrosting, controlling the operating states of the outdoor unit and the indoor unit to balance and stabilize the ratio of the discharge pressure to the suction pressure of the compressor. Through the above three progressive defrosting stages, controlling the components of the air conditioner to be in different operating states can improve the automatic defrosting effect of the air conditioner, and thus bring a better user experience to users.

Description

Technical Field

[0001] The present invention belongs to the technical field of temperature regulation, and particularly relates to a defrosting control method, device, storage medium and air conditioner for an air conditioner, and particularly relates to a method, device, storage medium and air conditioner for implementing a defrosting control logic of an air conditioner. Background Art

[0002] When an air conditioner operates in winter, affected by the external environmental temperature and humidity, the heat exchanger of the outdoor unit is prone to frosting. In related technologies, when a heat pump type bus air conditioner performs automatic defrosting control, if it cannot effectively defrost or the defrosting efficiency is low, it may cause the fins of the outdoor unit heat exchanger to be blocked, the heat transfer thermal resistance of the heat exchanger to increase, and in severe cases, it directly affects the performance of the heat exchanger, resulting in the abnormal operation of the air conditioner and greatly affecting the user experience. The automatic defrosting control of a heat pump type bus air conditioner is related to the comfort during the operation of the whole vehicle. Effective defrosting control can improve the comfort of the whole vehicle. Therefore, it is necessary to optimize the defrosting control method of the air conditioner to solve the problem of low defrosting efficiency.

[0003] The above content is only used to assist in understanding the technical solution of the present invention, and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The purpose of the present invention is to provide a defrosting control method, device, storage medium and air conditioner for an air conditioner. By setting three different stages, namely the initial defrosting stage, the middle defrosting stage and the final defrosting stage, in the defrosting mode of the air conditioner, the outdoor unit and the indoor unit of the air conditioner are in different operating states at different stages, so as to improve the defrosting efficiency of the air conditioner.

[0005] The present invention provides a defrosting control method for an air conditioner, which is applied to an automotive air conditioner; the air conditioner includes an outdoor unit and an indoor unit, the outdoor unit has outdoor unit components, the outdoor unit components include a compressor, and the indoor unit has indoor unit components; the defrosting control method of the air conditioner includes: when the air conditioner enters the defrosting mode, in the initial stage of defrosting in the defrosting mode, controlling the operating state of the outdoor unit components in the outdoor unit to be adjusted to a first outdoor unit operating state, and controlling the operating state of the indoor unit components in the indoor unit to be adjusted to a first indoor unit operating state, so as to reduce the ratio of the discharge pressure to the suction pressure of the compressor; determining a first operating parameter of the outdoor unit components, and if the first operating parameter meets the condition for exiting the initial stage of defrosting, exiting the initial stage of defrosting and entering the middle stage of defrosting in the defrosting mode; in the middle stage of defrosting, controlling the operating state of the outdoor unit components in the outdoor unit to be adjusted to a second outdoor unit operating state, and controlling the operating state of the indoor unit components in the indoor unit to be adjusted to a second indoor unit operating state to defrost the outdoor unit; determining a second operating parameter of the outdoor unit components, and if the second operating parameter meets the condition for exiting the middle stage of defrosting, exiting the middle stage of defrosting and entering the final stage of defrosting in the defrosting mode; in the final stage of defrosting, controlling the operating state of the outdoor unit components in the outdoor unit to be adjusted to a third outdoor unit operating state, and controlling the operating state of the indoor unit components in the indoor unit to be adjusted to a third indoor unit operating state, so as to balance and stabilize the ratio of the discharge pressure to the suction pressure of the compressor; determining a third operating parameter of the outdoor unit components, and if the third operating parameter meets the condition for exiting the final stage of defrosting, exiting the final stage of defrosting to exit the defrosting mode.

[0006] In some embodiments, the outdoor unit components include: an outdoor fan, a four-way valve, a throttling element, an outdoor heat exchanger, and a low-pressure switch. The low-pressure switch is a protection device for protecting the pressure system of the air conditioner to prevent the air conditioner from shutting down due to too low system pressure. The indoor unit components include an indoor fan. In the initial defrosting stage of the defrosting mode, control the operating states of the outdoor unit components in the outdoor unit to be adjusted to a first outdoor unit operating state, and control the operating states of the indoor unit components in the indoor unit to be adjusted to a first indoor unit operating state, so as to reduce the ratio of the discharge pressure to the suction pressure of the compressor, including: controlling the compressor to operate at a first operating frequency, controlling the outdoor fan to operate at a first outdoor fan speed, controlling the four-way valve to be in a first state so that the outdoor heat exchanger operates as the evaporator of the air conditioner, controlling the opening degree of the throttling element to reach a first opening degree, controlling the low-pressure switch to perform normal control according to a preset normal protection logic, and controlling the indoor fan to operate at a first indoor fan speed; determining the first operating parameters of the outdoor unit components, and if the first operating parameters meet the conditions for exiting the initial defrosting stage, then exit the initial defrosting stage and enter the intermediate defrosting stage of the defrosting mode, including: determining that the operating frequency of the compressor reaches the first operating frequency and operates for a first preset duration, then exit the initial defrosting stage and enter the intermediate defrosting stage of the defrosting mode; or determining that the air conditioner operates for a second preset duration after entering the initial defrosting stage, then exit the initial defrosting stage and enter the intermediate defrosting stage of the defrosting mode.

[0007] In some embodiments, the first operating frequency is the minimum operating frequency of the compressor, the first outdoor fan speed is half of the maximum speed of the outdoor fan, the first opening degree is one-fourth of the maximum opening degree of the throttling element, and the first indoor fan speed is the maximum speed of the indoor fan.

[0008] In some embodiments, during the mid - stage of defrosting, the operating states of the external - unit components in the external unit are controlled to be adjusted to the second external - unit operating state, and the operating states of the internal - unit components in the internal unit are controlled to be adjusted to the second internal - unit operating state to defrost the external unit, including: controlling the operating frequency of the compressor to be converted from the first operating frequency to the second operating frequency, controlling the external fan to be turned off, controlling the four - way valve to be in the second state so that the external - unit heat exchanger operates as the condenser of the air conditioner, controlling the opening degree of the throttling element to reach the second opening degree, shielding the normal protection logic of the low - pressure switch, and controlling the internal fan to be turned off; determining the second operating parameters of the external - unit components, and if the second operating parameters meet the conditions for exiting the mid - stage of defrosting, then exiting the mid - stage of defrosting and entering the end - stage of defrosting in the defrosting mode, including: if the external - unit ambient temperature is greater than or equal to the first preset temperature, determining that the minimum value of the external - unit heat - exchanger tube temperature is greater than the second preset temperature and lasts for the third preset duration, then exiting the mid - stage of defrosting and entering the end - stage of defrosting in the defrosting mode; or determining that the minimum value of the external - unit heat - exchanger tube temperature is greater than the third preset temperature and lasts for the fourth preset duration, then exiting the mid - stage of defrosting and entering the end - stage of defrosting in the defrosting mode; or after the air conditioner enters the mid - stage of defrosting and operates for the fifth preset duration, then exiting the mid - stage of defrosting and entering the end - stage of defrosting in the defrosting mode; if the external - unit ambient temperature is less than the first preset temperature, determining that the minimum value of the external - unit heat - exchanger tube temperature is greater than the fourth preset temperature and lasts for the sixth preset duration, then exiting the mid - stage of defrosting and entering the end - stage of defrosting in the defrosting mode; or determining that the minimum value of the external - unit heat - exchanger tube temperature is greater than the fifth preset temperature and lasts for the seventh preset duration, then exiting the mid - stage of defrosting and entering the end - stage of defrosting in the defrosting mode; or after the air conditioner enters the mid - stage of defrosting and operates for the fifth preset duration, then exiting the mid - stage of defrosting and entering the end - stage of defrosting in the defrosting mode; wherein, the second operating frequency is the maximum operating frequency of the compressor, and the second opening degree is the maximum opening degree of the throttling element.

[0009] In some embodiments, in the final stage of defrosting, the operating states of the external unit components in the external unit are controlled to be adjusted to the third external unit operating state, and the operating states of the internal unit components in the internal unit are controlled to be adjusted to the third internal unit operating state, so as to balance and stabilize the ratio of the discharge pressure to the suction pressure of the compressor, including: controlling the operating frequency of the compressor to be converted from the second operating frequency to the first operating frequency, controlling the external fan to operate at the first external fan speed, controlling the four-way valve to be converted to the first state after an eighth preset time period after the compressor reaches the first operating frequency so that the external unit heat exchanger operates as the evaporator of the air conditioner, controlling the opening degree of the throttling element to reach the third opening degree, shielding the normal protection logic of the low-pressure switch, and controlling the internal fan to be turned off; determining the third operating parameter of the external unit components, and if the third operating parameter meets the condition for exiting the final stage of defrosting, exiting the final stage of defrosting to exit the defrosting mode, including: determining that the operating time after the four-way valve is converted to the first state reaches the ninth preset time period, then exiting the final stage of defrosting; wherein, the third opening degree is one-third of the maximum opening degree of the throttling element; exiting the final stage of defrosting includes: the air conditioner exiting the defrosting mode and entering the normal heating operation mode.

[0010] Matched with the above method, on the other hand, the present invention provides a defrosting control device for an air conditioner, which is characterized in that it is applied to an automotive air conditioner; the air conditioner includes an outdoor unit and an indoor unit, the outdoor unit has outdoor unit components, the outdoor unit components include a compressor, and the indoor unit has indoor unit components; the defrosting control device of the air conditioner includes: a control unit configured to, when the air conditioner enters the defrosting mode, in the initial stage of defrosting in the defrosting mode, control the operating state of the outdoor unit components in the outdoor unit to be adjusted to a first outdoor unit operating state, and control the operating state of the indoor unit components in the indoor unit to be adjusted to a first indoor unit operating state, so as to reduce the ratio of the discharge pressure to the suction pressure of the compressor; a determination unit configured to determine a first operating parameter of the outdoor unit components, and if the first operating parameter meets the condition for exiting the initial stage of defrosting, exit the initial stage of defrosting and enter the intermediate stage of defrosting in the defrosting mode; the control unit is further configured to, in the intermediate stage of defrosting, control the operating state of the outdoor unit components in the outdoor unit to be adjusted to a second outdoor unit operating state, and control the operating state of the indoor unit components in the indoor unit to be adjusted to a second indoor unit operating state to defrost the outdoor unit; the determination unit is further configured to determine a second operating parameter of the outdoor unit components, and if the second operating parameter meets the condition for exiting the intermediate stage of defrosting, exit the intermediate stage of defrosting and enter the final stage of defrosting in the defrosting mode; the control unit is further configured to, in the final stage of defrosting, control the operating state of the outdoor unit components in the outdoor unit to be adjusted to a third outdoor unit operating state, and control the operating state of the indoor unit components in the indoor unit to be adjusted to a third indoor unit operating state, so as to balance and stabilize the ratio of the discharge pressure to the suction pressure of the compressor; the determination unit is further configured to determine a third operating parameter of the outdoor unit components, and if the third operating parameter meets the condition for exiting the final stage of defrosting, exit the final stage of defrosting to exit the defrosting mode.

[0011] In some embodiments, the outdoor unit components include: an outdoor fan, a four-way valve, a throttling element, an outdoor heat exchanger, and a low-pressure switch. The low-pressure switch is a protection device for protecting the pressure system of the air conditioner from the shutdown of the air conditioner caused by too low system pressure. The indoor unit components include an indoor fan; a control unit configured to, when the air conditioner enters the defrosting mode, in the initial defrosting stage of the defrosting mode, adjust the operating state of the outdoor unit components in the outdoor unit to a first outdoor unit operating state, and adjust the operating state of the indoor unit components in the indoor unit to a first indoor unit operating state, so as to reduce the ratio of the discharge pressure to the suction pressure of the compressor, including: the control unit is specifically configured to control the compressor to operate at a first operating frequency, control the outdoor fan to operate at a first outdoor fan speed, control the four-way valve to be in a first state so that the outdoor heat exchanger operates as the evaporator of the air conditioner, control the opening degree of the throttling element to reach a first opening degree, control the low-pressure switch to perform normal control according to a preset normal protection logic, and control the indoor fan to operate at a first indoor fan speed; a determination unit configured to determine a first operating parameter of the outdoor unit components. If the first operating parameter meets the condition for exiting the initial defrosting stage, then exit the initial defrosting stage and enter the intermediate defrosting stage of the defrosting mode, including: the determination unit is specifically configured to determine that the operating frequency of the compressor reaches the first operating frequency and operates for a first preset duration, then exit the initial defrosting stage and enter the intermediate defrosting stage of the defrosting mode; or determine that the air conditioner has operated for a second preset duration after entering the initial defrosting stage, then exit the initial defrosting stage and enter the intermediate defrosting stage of the defrosting mode.

[0012] In some embodiments, the first operating frequency is the minimum operating frequency of the compressor, the first outdoor fan speed is half of the maximum speed of the outdoor fan, the first opening degree is one-fourth of the maximum opening degree of the throttling element, and the first indoor fan speed is the maximum speed of the indoor fan.

[0013] In some embodiments, the control unit is further configured to, in the middle stage of defrosting, control the operating states of the external unit components in the external unit to be adjusted to the second external unit operating state, and control the operating states of the internal unit components in the internal unit to be adjusted to the second internal unit operating state, and perform defrosting on the external unit, including: the control unit is specifically configured to control the operating frequency of the compressor to be converted from the first operating frequency to the second operating frequency, control the external fan to be turned off, control the four-way valve to be in the second state so that the external unit heat exchanger operates as the condenser of the air conditioner, control the opening degree of the throttling element to reach the second opening degree, shield the normal protection logic of the low-pressure switch, and control the internal fan to be turned off; the determining unit is further configured to determine the second operating parameters of the external unit components, and if the second operating parameters meet the conditions for exiting the middle stage of defrosting, then exit the middle stage of defrosting and enter the final stage of defrosting in the defrosting mode, including: the determining unit is specifically configured to if the external unit ambient temperature is greater than or equal to the first preset temperature, determine that the minimum value of the external unit heat exchanger tube temperature is greater than the second preset temperature and lasts for the third preset duration, then exit the middle stage of defrosting and enter the final stage of defrosting in the defrosting mode; or determine that the minimum value of the external unit heat exchanger tube temperature is greater than the third preset temperature and lasts for the fourth preset duration, then exit the middle stage of defrosting and enter the final stage of defrosting in the defrosting mode; or after the air conditioner enters the middle stage of defrosting and operates for the fifth preset duration, then exit the middle stage of defrosting and enter the final stage of defrosting in the defrosting mode; the determining unit is specifically configured to if the external unit ambient temperature is less than the first preset temperature, determine that the minimum value of the external unit heat exchanger tube temperature is greater than the fourth preset temperature and lasts for the sixth preset duration, then exit the middle stage of defrosting and enter the final stage of defrosting in the defrosting mode; or determine that the minimum value of the external unit heat exchanger tube temperature is greater than the fifth preset temperature and lasts for the seventh preset duration, then exit the middle stage of defrosting and enter the final stage of defrosting in the defrosting mode; or after the air conditioner enters the middle stage of defrosting and operates for the fifth preset duration, then exit the middle stage of defrosting and enter the final stage of defrosting in the defrosting mode; wherein, the second operating frequency is the maximum operating frequency of the compressor, and the second opening degree is the maximum opening degree of the throttling element.

[0014] In some embodiments, the control unit is further configured to, in the late defrosting stage, control the operating states of the outdoor unit components in the outdoor unit to be adjusted to a third outdoor unit operating state, and control the operating states of the indoor unit components in the indoor unit to be adjusted to a third indoor unit operating state, so as to balance and stabilize the ratio of the discharge pressure to the suction pressure of the compressor, including: the control unit is specifically configured to control the operating frequency of the compressor to be converted from a second operating frequency to a first operating frequency, control the outdoor fan to operate at a first outdoor fan speed, control the four-way valve to be converted to a first state after an eighth preset time period after the compressor reaches the first operating frequency so that the outdoor heat exchanger operates as the evaporator of the air conditioner, control the opening degree of the throttling element to reach a third opening degree, shield the normal protection logic of the low-pressure switch, and control the indoor fan to be turned off; the determining unit is further configured to determine a third operating parameter of the outdoor unit components, and if the third operating parameter meets the condition for exiting the late defrosting stage, then exit the late defrosting stage to exit the defrosting mode, including: the determining unit is specifically configured to determine that the operating time after the four-way valve is converted to the first state reaches a ninth preset time period, then exit the late defrosting stage; wherein, the third opening degree is one-third of the maximum opening degree of the throttling element; the determining unit is further configured to the exiting of the late defrosting stage includes: the air conditioner exits the defrosting mode and enters the normal heating operation mode.

[0015] Matched with the above method, on the other hand, the present invention provides a storage medium, which includes a stored program. When the program runs, it controls the device where the storage medium is located to execute the defrosting control method of the air conditioner described above.

[0016] Matched with the above device, on the other hand, the present invention provides an air conditioner, including: the defrosting control device of the air conditioner described above.

[0017] The present invention provides a defrosting control method for an air conditioner, which is mainly applied to the automatic defrosting control of a heat pump type bus air conditioner. The entire control method is executed progressively in different stages, and different control strategies are adopted in each stage to control the operation of each component of the air conditioner, so as to achieve efficient automatic defrosting of the air conditioner. This control method includes three progressive control stages, namely, the initial defrosting stage, the middle defrosting stage, and the final defrosting stage. By controlling the operating states of components such as the compressor, outdoor fan, four-way valve, indoor fan, and low-pressure switch of the air conditioner in each stage, the defrosting effect of the air conditioner can be improved, and the air conditioner can always be in a safe and reliable operating state, thereby bringing a better user experience to passengers. In the initial defrosting stage, by controlling the operating states of each component, the system pressure difference of the air conditioning system is reduced, preventing liquid hammer from occurring in the compressor during defrosting and causing abnormal wear of the compressor. In the middle defrosting stage, by controlling the operating states of each component, the defrosting efficiency of the air conditioner can be effectively improved, the defrosting time can be shortened, and the excessive decrease in the vehicle interior temperature caused by too long defrosting time can be avoided, bringing an adverse user experience. In the final defrosting stage, on the premise of ensuring the safety and reliability of the system, the operating states of each component of the air conditioner are controlled to quickly end the defrosting mode and return to the heating mode to restore heating in the vehicle, timely meeting the user's usage requirements.

[0018] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention.

[0019] The technical solution of the present invention will be further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic flowchart of an embodiment of the method of the present invention;

[0021] Figure 2 is a schematic flowchart of an embodiment for controlling the operating states of each outdoor unit component and indoor unit component in the initial defrosting stage of the method of the present invention and determining the timely entry into the middle defrosting stage;

[0022] Figure 3 is a schematic flowchart of an embodiment for controlling the operating states of each outdoor unit component and indoor unit component in the middle defrosting stage of the method of the present invention and determining the timely entry into the final defrosting stage;

[0023] Figure 4 is a schematic flowchart of an embodiment for controlling the operating states of each outdoor unit component and indoor unit component in the final defrosting stage of the method of the present invention and determining the timely end of the final defrosting stage;

[0024] Figure 5 is a schematic structural diagram of an embodiment of the device of the present invention;

[0025] Figure 6 A flowchart of an embodiment of a method for implementing defrost control logic of an air conditioner;

[0026] In combination with the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0027] 102 - Control unit; 104 - Determination unit. Detailed implementation manners

[0028] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in combination with specific embodiments of the present invention and the corresponding accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention.

[0029] Considering that, for the defrost control of an air conditioner, such as the defrost control of the outdoor unit of a heat pump type bus air conditioner, if the outdoor heat exchanger cannot be effectively defrosted, or the defrosting efficiency is low and it cannot defrost quickly, it may cause the fins of the outdoor heat exchanger to be frosted and blocked, increasing the heat transfer thermal resistance of the heat exchanger. Seriously, it will directly affect the performance of the heat exchanger, resulting in the air conditioner not being able to operate normally, and greatly affecting the user's experience and favorability. Therefore, it is necessary to reasonably optimize the defrost control method of the air conditioner, especially the defrost control method of the heat pump type bus air conditioner, to improve the defrost efficiency of the air conditioner.

[0030] Therefore, the solution of the present invention provides a defrost control method for an air conditioner, which is mainly applied to the automatic defrost control of a heat pump type bus air conditioner. By setting three different stages, namely the initial defrost stage, the mid - defrost stage, and the end - defrost stage, in the defrost mode of the air conditioner, the outdoor unit and the indoor unit of the air conditioner are in different operating states at different stages, so as to improve the defrost efficiency of the air conditioner and meet the user's usage requirements.

[0031] According to an embodiment of the present invention, a defrost control method for an air conditioner is provided, as Figure 1 shown in the flowchart of an embodiment of the method of the present invention. The defrost control method of the air conditioner is applied to an automotive air conditioner; the air conditioner includes an outdoor unit and an indoor unit, the outdoor unit has outdoor components, the outdoor components include a compressor, and the indoor unit has indoor components; the defrost control method of the air conditioner includes: step S110 to step S160.

[0032] At step S110, when the air conditioner enters the defrosting mode, at the initial defrosting stage of the defrosting mode, control the operating state of the outdoor unit components in the outdoor unit to be adjusted to the first outdoor unit operating state, and control the operating state of the indoor unit components in the indoor unit to be adjusted to the first indoor unit operating state, so as to reduce the ratio of the discharge pressure to the suction pressure of the compressor.

[0033] At step S120, determine the first operating parameter of the outdoor unit components. If the first operating parameter reaches the condition for exiting the initial defrosting stage, then exit the initial defrosting stage and enter the intermediate defrosting stage of the defrosting mode.

[0034] At step S130, in the intermediate defrosting stage, control the operating state of the outdoor unit components in the outdoor unit to be adjusted to the second outdoor unit operating state, and control the operating state of the indoor unit components in the indoor unit to be adjusted to the second indoor unit operating state, and defrost the outdoor unit.

[0035] At step S140, determine the second operating parameter of the outdoor unit components. If the second operating parameter reaches the condition for exiting the intermediate defrosting stage, then exit the intermediate defrosting stage and enter the final defrosting stage of the defrosting mode.

[0036] At step S150, in the final defrosting stage, control the operating state of the outdoor unit components in the outdoor unit to be adjusted to the third outdoor unit operating state, and control the operating state of the indoor unit components in the indoor unit to be adjusted to the third indoor unit operating state, so as to balance and stabilize the ratio of the discharge pressure to the suction pressure of the compressor.

[0037] At step S160, determine the third operating parameter of the outdoor unit components. If the third operating parameter reaches the condition for exiting the final defrosting stage, then exit the final defrosting stage to exit the defrosting mode.

[0038] In some embodiments, the outdoor unit components include: an outdoor fan, a four-way valve, a throttling element, an outdoor heat exchanger, and a low-pressure switch. The low-pressure switch is a protection device for protecting the pressure system of the air conditioner from shutting down due to too low system pressure; the indoor unit components include an indoor fan. For the specific process of controlling the operating state of the outdoor unit components in the outdoor unit to be adjusted to the first outdoor unit operating state and the operating state of the indoor unit components in the indoor unit to be adjusted to the first indoor unit operating state at the initial defrosting stage of the defrosting mode when the air conditioner enters the defrosting mode in step S110, so as to reduce the ratio of the discharge pressure to the suction pressure of the compressor, refer to the following exemplary description.

[0039] The following combines Figure 2The following is a schematic flowchart of an embodiment for controlling the operating states of each outdoor unit component and indoor unit component in the initial defrosting stage of the method of the present invention and determining the timely entry into the middle defrosting stage, further illustrating that in step S110, when the air conditioner enters the defrosting mode, in the initial defrosting stage of the defrosting mode, the operating state of the outdoor unit components in the outdoor unit is controlled to be adjusted to the first outdoor unit operating state, and the operating state of the indoor unit components in the indoor unit is controlled to be adjusted to the first indoor unit operating state, so as to reduce the ratio of the discharge pressure to the suction pressure of the compressor, including step S210. In step S120, the first operating parameter of the outdoor unit components is determined. If the first operating parameter meets the condition for exiting the initial defrosting stage, then the initial defrosting stage is exited and the middle defrosting stage of the defrosting mode is entered, including step S220.

[0040] Step S210, controlling the compressor to operate at the first operating frequency, controlling the outdoor fan to rotate at the first outdoor fan speed, controlling the four-way valve to be in the first state so that the outdoor heat exchanger operates as the evaporator of the air conditioner, controlling the opening degree of the throttling element to reach the first opening degree, controlling the low-pressure switch to perform normal control according to the preset normal protection logic, and controlling the indoor fan to rotate at the first indoor fan speed.

[0041] Step S220, determining that the operating frequency of the compressor reaches the first operating frequency and operates for the first preset duration, then exiting the initial defrosting stage and entering the middle defrosting stage of the defrosting mode; or determining that the air conditioner enters the initial defrosting stage and operates for the second preset duration, then exiting the initial defrosting stage and entering the middle defrosting stage of the defrosting mode.

[0042] In some embodiments, in the specific process of step S210 controlling the compressor to operate at the first operating frequency, controlling the external fan to operate at the first external fan speed, controlling the four-way valve to be in the first state so that the outdoor heat exchanger operates as the evaporator of the air conditioner, controlling the opening degree of the throttling element to reach the first opening degree, controlling the low-pressure switch to perform normal control according to the preset normal protection logic, and controlling the internal fan to operate at the first internal fan speed, the first operating frequency is the minimum operating frequency of the compressor, the first external fan speed is half of the maximum speed of the external fan, the first opening degree is one-fourth of the maximum opening degree of the throttling element, and the first internal fan speed is the maximum speed of the internal fan. In the specific process of step S220 determining that the operating frequency of the compressor reaches the first operating frequency and operates for the first preset duration, then exiting the initial defrosting stage and entering the middle defrosting stage of the defrosting mode; or determining that the air conditioner enters the initial defrosting stage and operates for the second preset duration, then exiting the initial defrosting stage and entering the middle defrosting stage of the defrosting mode, the first preset duration is 15 seconds, and the second preset duration is 180 seconds.

[0043] In this embodiment, after entering the defrosting mode of the air conditioner, it first enters the initial defrosting stage of the defrosting mode. In this stage, the air conditioner compressor is controlled to operate at the minimum frequency at which the compressor itself can operate. For example, in some compressors, the minimum frequency can be 22 Hz. Setting it to operate at the minimum frequency can reduce the pressure difference of the refrigerant in the air-conditioning system, that is, reduce the ratio of the discharge pressure to the suction pressure of the compressor. The external fan is controlled to operate at a medium speed, and this setting is also beneficial to reducing the system pressure difference. The four-way valve is in the open state, so that the outdoor heat exchanger still serves as the evaporator. The throttling element is controlled to be in a small opening state. The throttling element can be an expansion valve or an electronic expansion valve, etc. The small opening state means that the opening degree of the expansion valve is small, for example, it can be one-fourth of the maximum opening degree, or ±20B. Controlling the internal fan to be at the maximum speed can also help reduce the system pressure difference. During heating, the internal fan plays a role in cooling the high-pressure gas discharged from the compressor in the internal heat exchanger. When other conditions are certain, the higher the internal fan speed, the more obvious the cooling effect, that is, the relatively smaller the system pressure, thereby reducing the system pressure difference. Combining the above settings of each component of the air conditioner can ensure that the refrigerant returns to the compressor in a gaseous form during the initial defrosting stage, and prevent the compressor from being damaged by liquid hammer due to excessive liquid refrigerant in the inhaled gas.

[0044] In some embodiments, in combination with Figure 3A schematic flowchart of an embodiment for controlling the operating states of each outdoor unit component and indoor unit component during the mid-stage of defrosting and determining the timely entry into the end-stage of defrosting in the method of the present invention is shown. Further explaining step S130, during the mid-stage of defrosting, controlling the operating state of the outdoor unit components in the outdoor unit to be adjusted to the second outdoor unit operating state, controlling the operating state of the indoor unit components in the indoor unit to be adjusted to the second indoor unit operating state, and defrosting the outdoor unit, including step S310. In step S140, determining the second operating parameter of the outdoor unit components, if the second operating parameter meets the condition for exiting the mid-stage of defrosting, then exiting the mid-stage of defrosting and entering the end-stage of defrosting in the defrosting mode, including step S320 and step S330.

[0045] Step S310, controlling the operating frequency of the compressor to be converted from the first operating frequency to the second operating frequency, controlling the outdoor fan to be turned off, controlling the four-way valve to be in the second state so that the outdoor heat exchanger operates as the condenser of the air conditioner, controlling the opening degree of the throttling element to reach the second opening degree, shielding the normal protection logic of the low-pressure switch, and controlling the indoor fan to be turned off.

[0046] Step S320, if the outdoor ambient temperature is greater than or equal to the first preset temperature, determining that the minimum value of the outdoor heat exchanger pipe temperature is greater than the second preset temperature and lasting for the third preset duration, then exiting the mid-stage of defrosting and entering the end-stage of defrosting in the defrosting mode; or determining that the minimum value of the outdoor heat exchanger pipe temperature is greater than the third preset temperature and lasting for the fourth preset duration, then exiting the mid-stage of defrosting and entering the end-stage of defrosting in the defrosting mode; or after the air conditioner enters the mid-stage of defrosting and operates for the fifth preset duration, then exiting the mid-stage of defrosting and entering the end-stage of defrosting in the defrosting mode.

[0047] Step S330, if the outdoor ambient temperature is less than the first preset temperature, determining that the minimum value of the outdoor heat exchanger pipe temperature is greater than the fourth preset temperature and lasting for the sixth preset duration, then exiting the mid-stage of defrosting and entering the end-stage of defrosting in the defrosting mode; or determining that the minimum value of the outdoor heat exchanger pipe temperature is greater than the fifth preset temperature and lasting for the seventh preset duration, then exiting the mid-stage of defrosting and entering the end-stage of defrosting in the defrosting mode; or after the air conditioner enters the mid-stage of defrosting and operates for the fifth preset duration, then exiting the mid-stage of defrosting and entering the end-stage of defrosting in the defrosting mode.

[0048] In some embodiments, in the specific process of step S310 controlling the operating frequency of the compressor to be converted from the first operating frequency to the second operating frequency, controlling the outdoor fan to turn off, controlling the four-way valve to be in the second state so that the outdoor heat exchanger operates as the condenser of the air conditioner, controlling the opening degree of the throttling element to reach the second opening degree, and shielding the normal protection logic of the low-pressure switch, and controlling the indoor fan to turn off, the second operating frequency is the maximum operating frequency of the compressor, and the second opening degree is the maximum opening degree of the throttling element. In the specific process of step S320, if the outdoor ambient temperature is greater than or equal to the first preset temperature, and it is determined that the minimum value of the outdoor heat exchanger pipe temperature is greater than the second preset temperature and lasts for the third preset duration, then exit the mid-stage defrosting stage and enter the final-stage defrosting stage of the defrosting mode; or it is determined that the minimum value of the outdoor heat exchanger pipe temperature is greater than the third preset temperature and lasts for the fourth preset duration, then exit the mid-stage defrosting stage and enter the final-stage defrosting stage of the defrosting mode; or after the air conditioner enters the mid-stage defrosting stage and operates for the fifth preset duration, then exit the mid-stage defrosting stage and enter the final-stage defrosting stage of the defrosting mode. And in the specific process of step S330, if the outdoor ambient temperature is less than the first preset temperature, and it is determined that the minimum value of the outdoor heat exchanger pipe temperature is greater than the fourth preset temperature and lasts for the sixth preset duration, then exit the mid-stage defrosting stage and enter the final-stage defrosting stage of the defrosting mode; or it is determined that the minimum value of the outdoor heat exchanger pipe temperature is greater than the fifth preset temperature and lasts for the seventh preset duration, then exit the mid-stage defrosting stage and enter the final-stage defrosting stage of the defrosting mode; or after the air conditioner enters the mid-stage defrosting stage and operates for the fifth preset duration, then exit the mid-stage defrosting stage and enter the final-stage defrosting stage of the defrosting mode, the first preset temperature is -2°C, the second preset temperature is 17°C, the third preset temperature is 10°C, the fourth preset temperature is 14°C, the fifth preset temperature is 9°C, the third preset duration is 3 seconds, the fourth preset duration is 15 seconds, the fifth preset duration is 240 seconds, the sixth preset duration is 6 seconds, and the seventh preset duration is 30 seconds.

[0049] In this embodiment, the defrosting enters the mid-stage of the defrosting mode after the initial stage of defrosting ends. In this stage, the frequency of the compressor is controlled to increase to the maximum frequency for operation. The maximum frequency is the maximum frequency limited by the normal operating state of the compressor. When controlling the increase of the operating frequency of the compressor, it can be increased at a rate of 5s / 2Hz. The four-way valve is controlled to close, so that the outdoor heat exchanger changes from the state of acting as an evaporator to the state of acting as a condenser. In this state, the outdoor heat exchanger can defrost the frost on its surface. The exit conditions of the mid-stage of defrosting can be divided into two aspects according to the temperature of the environment where the outdoor unit is located. When it is determined that the outdoor ambient temperature is greater than or equal to the first preset temperature, it is further determined whether to exit the initial stage of defrosting according to the minimum temperature of the heat exchange tubes of the outdoor heat exchanger. The first preset temperature can be set according to the frosting situation of the outdoor heat exchanger. For example, the first preset temperature can be -2°C. The minimum tube temperature of the heat exchange tubes of the outdoor heat exchanger can be detected by a temperature sensor set on the outdoor unit. For example, a temperature sensor can be set on the middle row of the bottom of the outdoor heat exchanger. For example, when the outdoor heat exchanger of a bus is placed at an angle of 30° to the horizontal direction and the number of rows of its heat exchange tubes is four rows, the temperature sensor can be placed on the third row of heat exchange tubes from top to bottom. The judgment temperature of the minimum tube temperature of the heat exchange tubes, the second preset temperature, can be 17°C, the third preset temperature can be 10°C, the fourth preset temperature can be 14°C, and the fifth preset temperature can be 9°C. The settings of each preset temperature can be specifically set based on the consideration of the melting situation of the frost layer in the experiment. At the same time, a condition for forcibly exiting the mid-stage of defrosting is also set, that is, after entering the mid-stage of defrosting for a preset duration, the mid-stage of defrosting can be forcibly exited and the final stage of defrosting can be entered. This can prevent the air conditioner from being in the defrosting mode for a long time, resulting in a decrease in the indoor environment temperature and a poor user experience.

[0050] In some embodiments, in combination with Figure 4 FIG. shows a schematic flow chart of an embodiment of controlling the operating states of each outdoor unit component and indoor unit component in the final stage of defrosting and determining the timely end of the final stage of defrosting in the method of the present invention. Further, in step S150, in the final stage of defrosting, the operating state of the outdoor unit components in the outdoor unit is controlled to be adjusted to the third outdoor unit operating state, and the operating state of the indoor unit components in the indoor unit is controlled to be adjusted to the third indoor unit operating state, so that the ratio of the discharge pressure to the suction pressure of the compressor is balanced and stable, including step S410. In step S160, the third operating parameter of the outdoor unit components is determined. If the third operating parameter meets the condition for exiting the final stage of defrosting, the final stage of defrosting is exited to exit the defrosting mode, including step S420.

[0051] Step S410: Control the operating frequency of the compressor to be converted from the second operating frequency to the first operating frequency, control the external fan to operate at the first external fan speed, control the four-way valve to be converted to the first state after an eighth preset duration when the compressor reaches the first operating frequency so that the external heat exchanger operates as the evaporator of the air conditioner, control the opening degree of the throttling element to reach the third opening degree, shield the normal protection logic of the low-pressure switch, and control the internal fan to turn off.

[0052] Step S420: Determine that the operating time after the four-way valve is converted to the first state reaches the ninth preset duration, and then exit the end stage of defrosting.

[0053] In some embodiments, in the specific process of step S410 controlling the operating frequency of the compressor to be converted from the second operating frequency to the first operating frequency, controlling the external fan to operate at the first external fan speed, controlling the four-way valve to be converted to the first state after an eighth preset duration when the compressor reaches the first operating frequency so that the external heat exchanger operates as the evaporator of the air conditioner, controlling the opening degree of the throttling element to reach the third opening degree, shielding the normal protection logic of the low-pressure switch, and controlling the internal fan to turn off, the third opening degree is one-third of the maximum opening degree of the throttling element, and the eighth preset duration is 30 seconds. In the specific process of step S420 determining that the operating time after the four-way valve is converted to the first state reaches the ninth preset duration and then exiting the end stage of defrosting, the ninth preset duration is 60 seconds. Exiting the end stage of defrosting includes: the air conditioner exits the defrosting mode and enters the normal heating mode operation.

[0054] In this embodiment, the end stage of the defrosting mode is entered after the mid-stage of defrosting ends. Control the compressor to reduce the operating frequency to the minimum frequency of the compressor, start the external fan to operate, and operate at a medium speed of the external fan speed. When the operating frequency of the compressor reaches the minimum frequency and lasts for 30 seconds, control the air-conditioning four-way valve to close, so that the external heat exchanger is in the state of acting as an evaporator, and the internal heat exchanger is in the state of acting as a condenser. Control the expansion valve to operate at a relatively small opening degree. The air-conditioning expansion valve plays a role in reducing pressure, and controls the air-conditioning expansion valve to ensure that there is a certain pressure difference in the refrigerant in the air-conditioning system during operation, so that the refrigerant can flow. Control the low-pressure switch protection to be in a shielded state to prevent the air-conditioning system from shutting down due to a fault reported by the system due to the too low suction pressure value of the compressor. In this stage, the external fan can blow off the water melted from the frost on the surface of the external heat exchange pipe, delaying the duration of the external heat exchange pipe frosting again.

[0055] After the initial defrosting stage, the mid-stage defrosting stage, and the final defrosting stage in the defrosting mode provided by the above embodiments are sequentially executed, the defrosting efficiency of the air conditioner can be improved, and there is basically no frost water residue on the fins of the heat exchanger. After the defrosting is completed, the air conditioner can operate normally. At the same time, when the above defrosting mode is executed, the phenomenon of liquid slugging of the compressor can be prevented, and there is no abnormal noise when the compressor is running.

[0056] Figure 6 FIG. is a schematic flow chart of an embodiment of an implementation method for the defrosting control logic of an air conditioner, specifically a schematic diagram of the automatic defrosting stage control logic of a heat pump type bus air conditioner. As Figure 6 shown in the implementation method of the defrosting control logic of the air conditioner, including:

[0057] After the air conditioner enters the defrosting control stage, it will sequentially enter the following three stages.

[0058] In the first stage, control the compressor in the outdoor unit of the air conditioner to run at the minimum frequency limited by the compressor. For example, the minimum frequency can be 22 Hz. Control the outdoor fan to rotate at a medium speed of the outdoor fan speed, that is, control the outdoor fan to maintain medium speed operation. Control the four-way valve to open, that is, keep the outdoor heat exchanger operating as the evaporator of the air conditioner. Control the opening degree of the expansion valve of the air conditioner to operate at one-fourth of the maximum opening degree of the expansion valve. Control the indoor fan of the indoor unit of the air conditioner to run at the maximum speed of the indoor fan speed, that is, control the indoor fan to maintain the highest wind gear operation. Control the low-pressure switch protection of the air conditioner to be in normal protection logic control.

[0059] The exit condition of the first stage is: Real-time detect the operating frequency of the compressor. When it is detected that the operating frequency of the compressor reaches the target frequency and continues to run for 15 s, then exit the first stage; or when the air conditioner enters the first stage, when the running duration reaches 180 s at the longest, forcefully exit the first stage. After exiting the first stage, enter the second stage.

[0060] In the second stage, control the compressor in the outdoor unit of the air conditioner to run at the maximum frequency limited by the compressor. Control the outdoor fan to shut down. Control the four-way valve to close, that is, keep the outdoor heat exchanger operating as the condenser of the air conditioner. Control the opening degree of the expansion valve of the air conditioner to reach the maximum opening degree of the expansion valve. Control the indoor fan of the indoor unit of the air conditioner to shut down. Control the low-pressure switch protection of the air conditioner to be in a shielded state, that is, exit the normal protection logic control.

[0061] The exit conditions of the second stage are one of the following:

[0062] (1) When the outer ring ≥ T1 °C, the minimum tube temperature of the outdoor heat exchanger > T2 °C, exit after 3 s continuously; or the minimum tube temperature of the outdoor heat exchanger > T3 °C, exit after 15 s continuously; or when the defrosting operation time reaches 4 min, forcefully exit.

[0063] (2) When the outer ring < T1 °C, the minimum pipe temperature of the outdoor heat exchanger > T4 °C, exit after 6 consecutive seconds; or the minimum pipe temperature of the outdoor heat exchanger > T5 °C, exit after 30 consecutive seconds; or when the defrosting operation time reaches 4 minutes, forcefully exit, and enter the third stage after exiting.

[0064] Optionally, T1 is -2 °C, T2 is 17 °C, T3 is 10 °C, T4 is 14 °C, and T5 is 9 °C.

[0065] In the third stage, control the compressor in the outdoor unit of the air conditioner to operate at the minimum frequency limited by the compressor. Control the external fan to maintain medium speed operation. First, control the four-way valve to close. When the operating frequency of the compressor reaches the minimum operating frequency, maintain for 30 seconds and then control the four-way valve to open, so that the outdoor heat exchanger switches from the condenser operating state to the evaporator operating state. Control the opening degree of the expansion valve of the air conditioner to operate at one-third of the maximum opening degree. Control the internal fan of the air conditioner to close. Control the low-pressure switch protection of the air conditioner to be in a shielded state, that is, exit the normal protection logic control.

[0066] The exit condition for the third stage is: When the four-way valve switches from the closed state to the open state within the longest 60 seconds, forcefully exit the defrosting mode, and the air conditioner enters normal heating operation after exiting.

[0067] The defrosting control method adopting this solution is mainly applied to the automatic defrosting control of heat pump type bus air conditioners. The entire control method is progressively executed in three different stages. Different control strategies are adopted in the three stages to control the operation of each component of the air conditioner to achieve efficient automatic defrosting of the air conditioner. In the initial stage of defrosting, by controlling the operating states of each component, the system pressure difference of the air conditioning system is reduced to prevent liquid slugging of the compressor during defrosting, which may cause abnormal wear of the compressor. In the middle stage of defrosting, by controlling the operating states of each component, the defrosting efficiency of the air conditioner can be effectively improved, the defrosting time can be shortened, and the excessive temperature drop inside the vehicle caused by too long defrosting time can be avoided, bringing a bad user experience. In the final stage of defrosting, on the premise of ensuring the safety and reliability of the system, control each component of the air conditioner to quickly end the defrosting mode and return to the heating mode to restore heating inside the vehicle in a timely manner to meet the user's usage requirements.

[0068] According to an embodiment of the present invention, there is also provided a defrosting control device for an air conditioner corresponding to the defrosting control method of the air conditioner. Refer to Figure 5 The structural schematic diagram of an embodiment of the device of the present invention is shown. This defrosting control device is applied to an automotive air conditioner; the air conditioner includes an outdoor unit and an indoor unit. The outdoor unit has outdoor components, and the outdoor components include a compressor. The indoor unit has indoor components; the defrosting control device of the air conditioner further includes: a control unit 102 and a determination unit 104.

[0069] The control unit 102 is configured to, when the air conditioner enters the defrosting mode, at the initial stage of defrosting in the defrosting mode, control the operating state of the outdoor unit components in the outdoor unit to be adjusted to the first outdoor unit operating state, and control the operating state of the indoor unit components in the indoor unit to be adjusted to the first indoor unit operating state, so as to reduce the ratio of the discharge pressure to the suction pressure of the compressor. For the specific functions and processes of this control unit 102, refer to step S110

[0070] The determination unit 104 is configured to determine the first operating parameter of the outdoor unit components. If the first operating parameter meets the condition for exiting the initial stage of defrosting, then exit the initial stage of defrosting and enter the intermediate stage of defrosting in the defrosting mode. For the specific functions and processes of this determination unit 104, refer to step S120

[0071] The control unit 102 is further configured to, in the intermediate stage of defrosting, control the operating state of the outdoor unit components in the outdoor unit to be adjusted to the second outdoor unit operating state, and control the operating state of the indoor unit components in the indoor unit to be adjusted to the second indoor unit operating state, so as to defrost the outdoor unit. For the specific functions and processes of this control unit 102, refer to step S130

[0072] The determination unit 104 is further configured to determine the second operating parameter of the outdoor unit components. If the second operating parameter meets the condition for exiting the intermediate stage of defrosting, then exit the intermediate stage of defrosting and enter the final stage of defrosting in the defrosting mode. For the specific functions and processes of this determination unit 104, refer to step S140

[0073] The control unit 102 is further configured to, in the final stage of defrosting, control the operating state of the outdoor unit components in the outdoor unit to be adjusted to the third outdoor unit operating state, and control the operating state of the indoor unit components in the indoor unit to be adjusted to the third indoor unit operating state, so as to balance and stabilize the ratio of the discharge pressure to the suction pressure of the compressor. For the specific functions and processes of this control unit 102, refer to step S150

[0074] The determination unit 104 is further configured to determine the third operating parameter of the outdoor unit components. If the third operating parameter meets the condition for exiting the final stage of defrosting, then exit the final stage of defrosting to exit the defrosting mode. For the specific functions and processes of this determination unit 104, refer to step S160

[0075] In some embodiments, the control unit 102 is specifically configured to control the compressor to operate at a first operating frequency, control the external fan to operate at a first external fan speed, control the four-way valve to be in a first state so that the external heat exchanger operates as the evaporator of the air conditioner, control the opening degree of the throttling element to reach a first opening degree, control the low-pressure switch to perform normal control according to a preset normal protection logic, and control the internal fan to operate at a first internal fan speed. For the specific functions and processes of this control unit 102, refer to step S210

[0076] The determination unit 104 is specifically configured to determine that when the operating frequency of the compressor reaches the first operating frequency and operates for a first preset duration, it exits the initial defrosting stage and enters the mid-stage of the defrosting mode; or determine that when the air conditioner operates for a second preset duration after entering the initial defrosting stage, it exits the initial defrosting stage and enters the mid-stage of the defrosting mode. For the specific functions and processes of this determination unit 104, refer to step S220

[0077] In some embodiments, in the specific process of the control unit 102 controlling the compressor to operate at a first operating frequency, controlling the external fan to operate at a first external fan speed, controlling the four-way valve to be in a first state so that the external heat exchanger operates as the evaporator of the air conditioner, controlling the opening degree of the throttling element to reach a first opening degree, controlling the low-pressure switch to perform normal control according to a preset normal protection logic, and controlling the internal fan to operate at a first internal fan speed, the first operating frequency is the minimum operating frequency of the compressor, the first external fan speed is half of the maximum speed of the external fan, the first opening degree is one-fourth of the maximum opening degree of the throttling element, and the first internal fan speed is the maximum speed of the internal fan. In the specific process that the determination unit 104 determines that the operating frequency of the compressor reaches the first operating frequency and operates for a first preset duration, and then exits the initial defrosting stage and enters the mid-stage of the defrosting mode; or determines that when the air conditioner operates for a second preset duration after entering the initial defrosting stage, it exits the initial defrosting stage and enters the mid-stage of the defrosting mode, the first preset duration is 15 seconds, and the second preset duration is 180 seconds

[0078] In this embodiment, after entering the defrost mode of the air conditioner, it first enters the initial stage of defrosting in the defrost mode. In this stage, the control unit 102 controls the air-conditioning compressor to operate at the minimum frequency at which the compressor itself can operate. For example, in some compressors, the minimum frequency can be 22 Hz. Setting it to operate at the minimum frequency can reduce the pressure difference of the refrigerant in the air-conditioning system, that is, reduce the ratio of the discharge pressure to the suction pressure of the compressor. The external fan is controlled to operate at a medium speed, and such a setting is also beneficial to reducing the system pressure difference. The four-way valve is in an open state, so that the outdoor heat exchanger still serves as an evaporator. The throttle element is controlled to be in a small opening state. The throttle element can be an expansion valve or an electronic expansion valve, etc. The small opening state means that the opening of the expansion valve is small, for example, it can be one-fourth of the maximum opening, or it can be ±20B. Controlling the internal fan to the maximum speed can also help reduce the system pressure difference. When heating, the internal fan plays a role in cooling the high-pressure gas discharged from the compressor in the internal heat exchanger. When other conditions are certain, the higher the wind speed of the internal fan, the more obvious the cooling effect, that is, the system pressure will be relatively smaller, thereby reducing the system pressure difference. Considering the above settings for each component of the air conditioner, it can ensure that the refrigerant returns to the compressor in a gaseous state in the initial stage of defrosting, and prevent the compressor from being damaged by liquid hammer due to excessive liquid refrigerant in the inhaled gas.

[0079] In some embodiments, the control unit 102 is specifically configured to control the operating frequency of the compressor to be converted from the first operating frequency to the second operating frequency, control the external fan to turn off, control the four-way valve to be in the second state so that the outdoor heat exchanger serves as the condenser of the air conditioner, control the opening of the throttle element to reach the second opening, shield the normal protection logic of the low-pressure switch, and control the internal fan to turn off. For the specific functions and processing of this control unit 102, refer to step S310.

[0080] The determination unit 104 is specifically configured to: if the outdoor ambient temperature is greater than or equal to the first preset temperature, determine that the minimum value of the outdoor heat exchanger pipe temperature is greater than the second preset temperature and lasts for the third preset duration, then exit the mid-stage of defrosting and enter the final stage of defrosting in the defrost mode; or determine that the minimum value of the outdoor heat exchanger pipe temperature is greater than the third preset temperature and lasts for the fourth preset duration, then exit the mid-stage of defrosting and enter the final stage of defrosting in the defrost mode; or after the air conditioner enters the mid-stage of defrosting and operates for the fifth preset duration, then exit the mid-stage of defrosting and enter the final stage of defrosting in the defrost mode. For the specific functions and processing of this determination unit 104, refer to step S320.

[0081] The determination unit 104 is specifically configured to, if the external unit ambient temperature is less than the first preset temperature, determine that the minimum value of the external unit heat exchanger pipe temperature is greater than the fourth preset temperature and lasts for the sixth preset duration, then exit the middle defrosting stage and enter the final defrosting stage of the defrosting mode; or determine that the minimum value of the external unit heat exchanger pipe temperature is greater than the fifth preset temperature and lasts for the seventh preset duration, then exit the middle defrosting stage and enter the final defrosting stage of the defrosting mode; or after the air conditioner enters the middle defrosting stage and operates for the fifth preset duration, then exit the middle defrosting stage and enter the final defrosting stage of the defrosting mode. For the specific functions and processing of this determination unit 104, refer to step S330.

[0082] In some embodiments, the control unit 102 is specifically configured to control the operating frequency of the compressor to be converted from a first operating frequency to a second operating frequency, control the outdoor fan to be turned off, control the four-way valve to be in a second state so that the outdoor heat exchanger operates as the condenser of the air conditioner, control the opening degree of the throttling element to reach a second opening degree, and shield the normal protection logic of the low-pressure switch. During the specific process of controlling the indoor fan to be turned off, the second operating frequency is the maximum operating frequency of the compressor, and the second opening degree is the maximum opening degree of the throttling element. The determining unit 104 is specifically configured to, if the outdoor ambient temperature is greater than or equal to a first preset temperature, determine that the minimum value of the outdoor heat exchanger tube temperature is greater than a second preset temperature and lasts for a third preset duration, then exit the mid-stage of defrosting and enter the final stage of defrosting in the defrosting mode; or determine that the minimum value of the outdoor heat exchanger tube temperature is greater than a third preset temperature and lasts for a fourth preset duration, then exit the mid-stage of defrosting and enter the final stage of defrosting in the defrosting mode; or during the specific process that the air conditioner exits the mid-stage of defrosting and enters the final stage of defrosting in the defrosting mode after operating for a fifth preset duration, and the determining unit 104 is specifically configured to, if the outdoor ambient temperature is less than the first preset temperature, determine that the minimum value of the outdoor heat exchanger tube temperature is greater than a fourth preset temperature and lasts for a sixth preset duration, then exit the mid-stage of defrosting and enter the final stage of defrosting in the defrosting mode; or determine that the minimum value of the outdoor heat exchanger tube temperature is greater than a fifth preset temperature and lasts for a seventh preset duration, then exit the mid-stage of defrosting and enter the final stage of defrosting in the defrosting mode; or during the specific process that the air conditioner exits the mid-stage of defrosting and enters the final stage of defrosting in the defrosting mode after operating for a fifth preset duration, the first preset temperature is -2°C, the second preset temperature is 17°C, the third preset temperature is 10°C, the fourth preset temperature is 14°C, the fifth preset temperature is 9°C, the third preset duration is 3 seconds, the fourth preset duration is 15 seconds, the fifth preset duration is 240 seconds, the sixth preset duration is 6 seconds, and the seventh preset duration is 30 seconds.

[0083] In this embodiment, the defrosting mid-stage is entered after the initial defrosting stage ends and the defrosting mode is entered. In this stage, the control unit 102 controls the frequency of the compressor to increase to the maximum frequency for operation. The maximum frequency is the maximum frequency limited in the normal operating state of the compressor. When controlling the operating frequency of the compressor to increase, it can be increased at a rate of 5s / 2Hz. The control unit 102 controls the four-way valve to close, so that the outdoor heat exchanger is converted from the evaporator function state to the condenser function state. In this state, the outdoor heat exchanger can defrost the frost on its surface. The exit conditions of the defrosting mid-stage can be divided into two aspects according to the temperature of the environment where the outdoor unit is located. When the determination unit 104 determines that the outdoor unit ambient temperature is greater than or equal to the first preset temperature, it further determines whether to exit the initial defrosting stage according to the minimum temperature of the heat exchange tubes of the outdoor heat exchanger. The first preset temperature can be set according to the frosting situation of the outdoor heat exchanger. For example, the first preset temperature can be -2°C. The minimum tube temperature of the heat exchange tubes of the outdoor heat exchanger can be detected by a temperature sensor arranged on the outdoor unit. For example, a temperature sensor can be arranged on the middle row of the bottom of the outdoor heat exchanger. For example, when the outdoor heat exchanger of a passenger car is placed at an angle of 30° to the horizontal direction and has four rows of heat exchange tubes, the temperature sensor can be placed on the third row of heat exchange tubes from top to bottom. The determination temperature of the minimum tube temperature of the heat exchange tubes, the second preset temperature, can be 17°C, the third preset temperature can be 10°C, the fourth preset temperature can be 14°C, and the fifth preset temperature can be 9°C. The settings of each preset temperature can be specifically set based on the consideration of the frost layer melting situation in the experiment. At the same time, a condition for forcibly exiting the defrosting mid-stage is also set, that is, after entering the defrosting mid-stage and reaching a preset duration, the defrosting mid-stage can be forcibly exited and the defrosting final stage can be entered. This can prevent the air conditioner from being in the defrosting mode for a long time, resulting in a decrease in the indoor unit ambient temperature and a poor user experience.

[0084] In some embodiments, the control unit 102 is specifically configured to control the operating frequency of the compressor to be converted from the second operating frequency to the first operating frequency for operation, control the outdoor fan to operate at the first outdoor fan speed, control the four-way valve to be converted to the first state after the eighth preset duration after the compressor reaches the first operating frequency so that the outdoor heat exchanger operates as the evaporator of the air conditioner, control the opening degree of the throttling element to reach the third opening degree, shield the normal protection logic of the low-pressure switch, and control the indoor fan to close. For the specific functions and processes of this control unit 102, refer to step S410.

[0085] The determination unit 104 is specifically configured to determine that the running time after the four-way valve is converted to the first state reaches the ninth preset duration, and then exit the defrosting final stage. For the specific functions and processes of this determination unit 104, refer to step S420.

[0086] In some embodiments, the control unit 102 is specifically configured to control the operating frequency of the compressor to be converted from a second operating frequency to a first operating frequency, control the external fan to operate at a first external fan speed, control the four-way valve to be converted to a first state after an eighth preset duration after the compressor reaches the first operating frequency so that the external heat exchanger operates as the evaporator of the air conditioner, control the opening degree of the throttling element to reach a third opening degree, shield the normal protection logic of the low-pressure switch, and control the internal fan to close. In the specific process, the third opening degree is one-third of the maximum opening degree of the throttling element, and the eighth preset duration is 30 seconds. The determination unit 104 is specifically configured to determine that the operating time after the four-way valve is converted to the first state reaches a ninth preset duration, and then exit the defrosting final stage. In the specific process, the ninth preset duration is 60 seconds. Exiting the defrosting final stage includes: the air conditioner exits the defrosting mode and enters the normal heating mode operation.

[0087] In this embodiment, the defrosting mid-stage is ended and the defrosting final stage of the defrosting mode is entered. The control unit 102 controls the compressor to reduce the operating frequency to the minimum frequency of the compressor, and the external fan starts to operate and operates at a medium speed of the external fan speed. When the operating frequency of the compressor reaches the minimum frequency and lasts for 30 seconds, the control unit 102 controls the air conditioner four-way valve to close, so that the external heat exchanger is in the evaporator function state and the internal heat exchanger is in the condenser function state. The control unit 102 controls the expansion valve to operate at a relatively small opening degree. The air conditioner expansion valve plays a role in reducing pressure, and controlling the air conditioner expansion valve ensures that there is a certain pressure difference in the refrigerant in the air conditioner system during operation, so that the refrigerant can flow. The control of the low-pressure switch protection is in a shielded state to prevent the air conditioner system from shutting down due to a fault reported by the system due to the too low suction pressure value of the compressor. In this stage, the external fan can blow off the water melted from the frost on the surface of the external heat exchange tube, delaying the duration of the external heat exchange tube frosting again.

[0088] After the defrosting initial stage, the defrosting mid-stage, and the defrosting final stage in the defrosting mode provided by the above embodiments are sequentially executed, the defrosting and defrosting efficiency of the air conditioner can be improved, there is basically no frost water residue on the fins of the heat exchanger, and the air conditioner can operate normally after defrosting is completed. At the same time, when the above defrosting mode is executed, the phenomenon of liquid slugging of the compressor can be prevented, and there is no abnormal noise when the compressor is operating.

[0089] The defrosting control method adopting this solution is mainly applied to the automatic defrosting control of a heat pump type bus air conditioner. The whole control method is progressively executed in three different stages. Different control strategies are adopted in the three stages to control the operation of each component of the air conditioner, so as to achieve efficient automatic defrosting of the air conditioner. In the initial stage of defrosting, by controlling the operation states of each component, the system pressure difference of the air conditioning system is reduced, preventing liquid slugging from occurring in the compressor during defrosting and causing abnormal wear of the compressor. In the middle stage of defrosting, by controlling the operation states of each component, the defrosting efficiency of the air conditioner can be effectively improved, the defrosting time can be shortened, and the excessive decrease of the vehicle interior temperature caused by too long defrosting time can be avoided, bringing an adverse user experience. In the final stage of defrosting, on the premise of ensuring the safety and reliability of the system, each component of the air conditioner is controlled to quickly end the defrosting mode and return to the heating mode to restore the heating in the vehicle, so as to meet the user's usage requirements in time.

[0090] According to an embodiment of the present invention, there is also provided a storage medium corresponding to the defrosting control method of the air conditioner. The storage medium includes a stored program, wherein when the program runs, it controls the device where the storage medium is located to execute the defrosting control method of the air conditioner described above.

[0091] Since the processing and functions realized by the storage medium of this embodiment are basically corresponding to the embodiments, principles and examples of the foregoing method, for the parts not described in detail in the description of this embodiment, reference can be made to the relevant descriptions in the foregoing embodiments, and details will not be repeated here.

[0092] The defrosting control method adopting this solution is mainly applied to the automatic defrosting control of a heat pump type bus air conditioner. The whole control method is progressively executed in three different stages. Different control strategies are adopted in the three stages to control the operation of each component of the air conditioner, so as to achieve efficient automatic defrosting of the air conditioner. In the initial stage of defrosting, by controlling the operation states of each component, the system pressure difference of the air conditioning system is reduced, preventing liquid slugging from occurring in the compressor during defrosting and causing abnormal wear of the compressor. In the middle stage of defrosting, by controlling the operation states of each component, the defrosting efficiency of the air conditioner can be effectively improved, the defrosting time can be shortened, and the excessive decrease of the vehicle interior temperature caused by too long defrosting time can be avoided, bringing an adverse user experience. In the final stage of defrosting, on the premise of ensuring the safety and reliability of the system, each component of the air conditioner is controlled to quickly end the defrosting mode and return to the heating mode to restore the heating in the vehicle, so as to meet the user's usage requirements in time.

[0093] According to an embodiment of the present invention, there is also provided an air conditioner corresponding to the defrosting control device of the air conditioner. The air conditioner may include: the defrosting control device of the air conditioner described above.

[0094] Since the processing and functions implemented by the air conditioner in this embodiment are basically corresponding to the embodiments, principles, and examples of the foregoing device, for the details not described in the description of this embodiment, reference may be made to the relevant descriptions in the foregoing embodiments and will not be elaborated here.

[0095] The defrosting control method adopting this solution is mainly applied to the automatic defrosting control of heat pump type bus air conditioners. The entire control method is progressively executed in three different stages. Different control strategies are adopted in the three stages to control the operation of each component of the air conditioner to achieve efficient automatic defrosting of the air conditioner. In the initial stage of defrosting, by controlling the operating states of each component, the system pressure difference of the air conditioning system is reduced to prevent liquid slugging of the compressor during defrosting and avoid abnormal wear of the compressor. In the middle stage of defrosting, by controlling the operating states of each component, the defrosting efficiency of the air conditioner can be effectively improved, the defrosting time can be shortened, and the excessive temperature drop inside the vehicle caused by too long defrosting time can be avoided, bringing an adverse user experience. In the final stage of defrosting, on the premise of ensuring the safety and reliability of the system, each component of the air conditioner is controlled to quickly end the defrosting mode and return to the heating mode to restore heating inside the vehicle in a timely manner to meet the user's usage requirements.

[0096] In summary, it is easy for those skilled in the art to understand that, on the premise of no conflict, the above-mentioned advantageous ways can be freely combined and superimposed.

[0097] The above are only the embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, various changes and modifications can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A defrosting control method for an air conditioner, characterized in that, Applied to automotive air conditioners; the air conditioner includes an outdoor unit and an indoor unit. The outdoor unit has outdoor unit components, and the outdoor unit components include a compressor. The indoor unit has indoor unit components; The defrost control method of the air conditioner includes: When the air conditioner enters the defrost mode, in the initial stage of defrosting in the defrost mode, control the operating state of the outdoor unit components in the outdoor unit to be adjusted to the first outdoor unit operating state, and control the operating state of the indoor unit components in the indoor unit to be adjusted to the first indoor unit operating state, so as to reduce the ratio of the discharge pressure to the suction pressure of the compressor; Determine the first operating parameter of the outdoor unit components. If the first operating parameter meets the condition for exiting the initial stage of defrosting, then exit the initial stage of defrosting and enter the intermediate stage of defrosting in the defrost mode; In the intermediate stage of defrosting, control the operating state of the outdoor unit components in the outdoor unit to be adjusted to the second outdoor unit operating state, and control the operating state of the indoor unit components in the indoor unit to be adjusted to the second indoor unit operating state to defrost the outdoor unit; Determine the second operating parameter of the outdoor unit components. If the second operating parameter meets the condition for exiting the intermediate stage of defrosting, then exit the intermediate stage of defrosting and enter the final stage of defrosting in the defrost mode; In the final stage of defrosting, control the operating state of the outdoor unit components in the outdoor unit to be adjusted to the third outdoor unit operating state, and control the operating state of the indoor unit components in the indoor unit to be adjusted to the third indoor unit operating state, so as to balance and stabilize the ratio of the discharge pressure to the suction pressure of the compressor; Determine the third operating parameter of the outdoor unit components. If the third operating parameter meets the condition for exiting the final stage of defrosting, then exit the final stage of defrosting to exit the defrost mode.

2. The defrosting control method of the air conditioner according to claim 1, characterized in that, The outdoor unit components include: an outdoor fan, a four-way valve, a throttling element, an outdoor heat exchanger, and a low-pressure switch. The low-pressure switch is a protection device for protecting the pressure system of the air conditioner to prevent the air conditioner from shutting down due to too low system pressure; the indoor unit components include an indoor fan; In the initial stage of defrosting in the defrost mode, controlling the operating state of the outdoor unit components in the outdoor unit to be adjusted to the first outdoor unit operating state, and controlling the operating state of the indoor unit components in the indoor unit to be adjusted to the first indoor unit operating state, so as to reduce the ratio of the discharge pressure to the suction pressure of the compressor, includes: Control the compressor to operate at the first operating frequency, control the outdoor fan to rotate at the first outdoor fan speed, control the four-way valve to be in the first state so that the outdoor heat exchanger operates as the evaporator of the air conditioner, control the opening degree of the throttling element to reach the first opening degree, control the low-pressure switch to perform normal control according to the preset normal protection logic, and control the indoor fan to rotate at the first indoor fan speed; Determine the first operating parameter of the outdoor unit components. If the first operating parameter meets the condition for exiting the initial stage of defrosting, then exit the initial stage of defrosting and enter the intermediate stage of defrosting in the defrost mode, including: Determine that the operating frequency of the compressor reaches the first operating frequency and operates for the first preset duration, then exit the initial defrosting stage and enter the middle defrosting stage of the defrosting mode; or determine that the air conditioner operates for the second preset duration after entering the initial defrosting stage, then exit the initial defrosting stage and enter the middle defrosting stage of the defrosting mode.

3. The defrosting control method of the air conditioner according to claim 2, wherein Wherein, the first operating frequency is the minimum operating frequency of the compressor, the first external fan speed is half of the maximum speed of the external fan, the first opening degree is one-fourth of the maximum opening degree of the throttling element, and the first internal fan speed is the maximum speed of the internal fan.

4. The defrosting control method of the air conditioner according to claim 2 or 3, characterized in that in the middle defrosting stage, control the operating states of the external machine components in the external machine to be adjusted to the second external machine operating state, control the operating states of the internal machine components in the internal machine to be adjusted to the second internal machine operating state, and defrost the external machine, including: control the operating frequency of the compressor to be converted from the first operating frequency to the second operating frequency for operation, control the external fan to be turned off, control the four-way valve to be in the second state so that the external heat exchanger operates as the condenser of the air conditioner, control the opening degree of the throttling element to reach the second opening degree, shield the normal protection logic of the low-pressure switch, and control the internal fan to be turned off; determine the second operating parameters of the external machine components, if the second operating parameters meet the conditions for exiting the middle defrosting stage, then exit the middle defrosting stage and enter the final defrosting stage of the defrosting mode, including: if the external machine ambient temperature is greater than or equal to the first preset temperature, determine that the minimum value of the external heat exchanger tube temperature is greater than the second preset temperature and lasts for the third preset duration, then exit the middle defrosting stage and enter the final defrosting stage of the defrosting mode; or determine that the minimum value of the external heat exchanger tube temperature is greater than the third preset temperature and lasts for the fourth preset duration, then exit the middle defrosting stage and enter the final defrosting stage of the defrosting mode; or the air conditioner operates for the fifth preset duration after entering the middle defrosting stage, then exit the middle defrosting stage and enter the final defrosting stage of the defrosting mode; if the external machine ambient temperature is less than the first preset temperature, determine that the minimum value of the external heat exchanger tube temperature is greater than the fourth preset temperature and lasts for the sixth preset duration, then exit the middle defrosting stage and enter the final defrosting stage of the defrosting mode; or determine that the minimum value of the external heat exchanger tube temperature is greater than the fifth preset temperature and lasts for the seventh preset duration, then exit the middle defrosting stage and enter the final defrosting stage of the defrosting mode; or the air conditioner operates for the fifth preset duration after entering the middle defrosting stage, then exit the middle defrosting stage and enter the final defrosting stage of the defrosting mode; wherein, the second operating frequency is the maximum operating frequency of the compressor, and the second opening degree is the maximum opening degree of the throttling element.

5. The defrosting control method of the air conditioner according to claim 2 or 3, characterized in that In the final stage of defrosting, control the operating state of the external unit components in the external unit to be adjusted to the third external unit operating state, and control the operating state of the internal unit components in the internal unit to be adjusted to the third internal unit operating state, so that the ratio of the discharge pressure to the suction pressure of the compressor is balanced and stable, including: Control the operating frequency of the compressor to be converted from the second operating frequency to the first operating frequency, control the external fan to operate at the first external fan speed, control the four-way valve to be converted to the first state after the eighth preset time period when the compressor reaches the first operating frequency so that the external unit heat exchanger operates as the evaporator of the air conditioner, control the opening of the throttling element to reach the third opening, shield the normal protection logic of the low-pressure switch, and control the internal fan to close; Determine the third operating parameter of the external unit components. If the third operating parameter meets the condition for exiting the final stage of defrosting, then exit the final stage of defrosting to exit the defrosting mode, including: Determine that the operating time after the four-way valve is converted to the first state reaches the ninth preset time period, then exit the final stage of defrosting; Wherein, the third opening is one-third of the maximum opening of the throttling element; Exiting the final stage of defrosting includes: the air conditioner exits the defrosting mode and enters the normal heating mode operation.

6. A defrosting control device for an air conditioner, characterized in that, Applied to automotive air conditioners; the air conditioner includes an external unit and an internal unit, the external unit has external unit components, the external unit components include a compressor, and the internal unit has internal unit components; The defrosting control device of the air conditioner includes: A control unit configured to, when the air conditioner enters the defrosting mode, in the initial stage of defrosting of the defrosting mode, control the operating state of the external unit components in the external unit to be adjusted to the first external unit operating state, and control the operating state of the internal unit components in the internal unit to be adjusted to the first internal unit operating state, so that the ratio of the discharge pressure to the suction pressure of the compressor is reduced; A determination unit configured to determine the first operating parameter of the external unit components. If the first operating parameter meets the condition for exiting the initial stage of defrosting, then exit the initial stage of defrosting and enter the intermediate stage of defrosting of the defrosting mode; The control unit is further configured to, in the intermediate stage of defrosting, control the operating state of the external unit components in the external unit to be adjusted to the second external unit operating state, and control the operating state of the internal unit components in the internal unit to be adjusted to the second internal unit operating state to defrost the external unit; The determination unit is further configured to determine the second operating parameter of the external unit components. If the second operating parameter meets the condition for exiting the intermediate stage of defrosting, then exit the intermediate stage of defrosting and enter the final stage of defrosting of the defrosting mode; The control unit is further configured to, in the final stage of defrosting, control the operating state of the external unit components in the external unit to be adjusted to the third external unit operating state, and control the operating state of the internal unit components in the internal unit to be adjusted to the third internal unit operating state, so that the ratio of the discharge pressure to the suction pressure of the compressor is balanced and stable; The determining unit is further configured to determine a third operating parameter of the outdoor unit components. If the third operating parameter meets the condition for exiting the end stage of defrosting, the end stage of defrosting is exited to exit the defrost mode.

7. The defrosting control device of the air conditioner according to claim 6, characterized in that, The outdoor unit components include: an outdoor fan, a four-way valve, a throttling element, an outdoor heat exchanger, and a low-pressure switch. The low-pressure switch is a protection device for protecting the pressure system of the air conditioner to prevent the air conditioner from shutting down due to too low system pressure. The indoor unit components include an indoor fan. The control unit is configured to, when the air conditioner enters the defrost mode, in the initial stage of defrosting of the defrost mode, control the operating state of the outdoor unit components in the outdoor unit to be adjusted to a first outdoor unit operating state, and control the operating state of the indoor unit components in the indoor unit to be adjusted to a first indoor unit operating state, so as to reduce the ratio of the discharge pressure to the suction pressure of the compressor, including: The control unit is specifically configured to control the compressor to operate at a first operating frequency, control the outdoor fan to operate at a first outdoor fan speed, control the four-way valve to be in a first state so that the outdoor heat exchanger operates as the evaporator of the air conditioner, control the opening degree of the throttling element to reach a first opening degree, control the low-pressure switch to perform normal control according to a preset normal protection logic, and control the indoor fan to operate at a first indoor fan speed. The determining unit is configured to determine a first operating parameter of the outdoor unit components. If the first operating parameter meets the condition for exiting the initial stage of defrosting, the initial stage of defrosting is exited to enter the intermediate stage of defrosting of the defrost mode, including: The determining unit is specifically configured to determine that the operating frequency of the compressor reaches the first operating frequency and operates for a first preset duration, then exit the initial stage of defrosting to enter the intermediate stage of defrosting of the defrost mode; or determine that the air conditioner operates for a second preset duration after entering the initial stage of defrosting, then exit the initial stage of defrosting to enter the intermediate stage of defrosting of the defrost mode.

8. The defrosting control device of the air conditioner according to claim 7, characterized in that, Wherein, The first operating frequency is the minimum operating frequency of the compressor, the first outdoor fan speed is half of the maximum speed of the outdoor fan, the first opening degree is one-fourth of the maximum opening degree of the throttling element, and the first indoor fan speed is the maximum speed of the indoor fan.

9. The defrost control device for an air conditioner according to claim 7 or 8, characterized in that The control unit is further configured to, in the intermediate stage of defrosting, control the operating state of the outdoor unit components in the outdoor unit to be adjusted to a second outdoor unit operating state, and control the operating state of the indoor unit components in the indoor unit to be adjusted to a second indoor unit operating state to defrost the outdoor unit, including: The control unit is specifically configured to control the operating frequency of the compressor to be converted from the first operating frequency to the second operating frequency for operation, control the outdoor fan to be turned off, control the four-way valve to be in a second state so that the outdoor heat exchanger operates as the condenser of the air conditioner, control the opening degree of the throttling element to reach a second opening degree, shield the normal protection logic of the low-pressure switch, and control the indoor fan to be turned off. The determining unit is further configured to determine a second operating parameter of the outdoor unit components. If the second operating parameter meets the condition for exiting the mid-stage of defrosting, then exit the mid-stage of defrosting and enter the final stage of defrosting in the defrosting mode, including: The determining unit is specifically configured to, if the outdoor unit ambient temperature is greater than or equal to a first preset temperature, determine that the minimum value of the outdoor unit heat exchanger tube temperature is greater than a second preset temperature and lasts for a third preset duration, then exit the mid-stage of defrosting and enter the final stage of defrosting in the defrosting mode; or determine that the minimum value of the outdoor unit heat exchanger tube temperature is greater than a third preset temperature and lasts for a fourth preset duration, then exit the mid-stage of defrosting and enter the final stage of defrosting in the defrosting mode; or after the air conditioner enters the mid-stage of defrosting and operates for a fifth preset duration, then exit the mid-stage of defrosting and enter the final stage of defrosting in the defrosting mode; The determining unit is specifically configured to, if the outdoor unit ambient temperature is less than the first preset temperature, determine that the minimum value of the outdoor unit heat exchanger tube temperature is greater than a fourth preset temperature and lasts for a sixth preset duration, then exit the mid-stage of defrosting and enter the final stage of defrosting in the defrosting mode; or determine that the minimum value of the outdoor unit heat exchanger tube temperature is greater than a fifth preset temperature and lasts for a seventh preset duration, then exit the mid-stage of defrosting and enter the final stage of defrosting in the defrosting mode; or after the air conditioner enters the mid-stage of defrosting and operates for a fifth preset duration, then exit the mid-stage of defrosting and enter the final stage of defrosting in the defrosting mode; Wherein, the second operating frequency is the maximum operating frequency of the compressor, and the second opening degree is the maximum opening degree of the throttling element.

10. The defrosting control device of an air conditioner according to claim 7 or 8, wherein The control unit is further configured to, in the final stage of defrosting, control the operating state of the outdoor unit components in the outdoor unit to be adjusted to a third outdoor unit operating state, and control the operating state of the indoor unit components in the indoor unit to be adjusted to a third indoor unit operating state, so as to balance and stabilize the ratio of the exhaust pressure to the suction pressure of the compressor, including: The control unit is specifically configured to control the operating frequency of the compressor to be converted from the second operating frequency to the first operating frequency, control the outdoor fan to operate at the first outdoor fan speed, control the four-way valve to be converted to the first state after an eighth preset duration when the compressor reaches the first operating frequency so that the outdoor unit heat exchanger operates as the evaporator of the air conditioner, control the opening degree of the throttling element to reach the third opening degree, shield the normal protection logic of the low-pressure switch, and control the indoor fan to turn off; The determining unit is further configured to determine a third operating parameter of the outdoor unit components. If the third operating parameter meets the condition for exiting the final stage of defrosting, then exit the final stage of defrosting to exit the defrosting mode, including: The determining unit is specifically configured to determine that the operating time after the four-way valve is converted to the first state reaches a ninth preset duration, then exit the final stage of defrosting; Wherein, the third opening degree is one-third of the maximum opening degree of the throttling element; The determining unit is further configured to exit the end stage of defrosting, including: the air conditioner exits the defrosting mode and enters the normal heating mode operation.

11. A storage medium, characterized in that, The storage medium includes a stored program, wherein when the program runs, it controls the device where the storage medium is located to execute the defrosting control method of the air conditioner according to any one of claims 1 to 5.

12. An air conditioner, characterized in that, Including: The defrosting control device of the air conditioner according to any one of claims 6 to 10.

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