CN107166639B - Air conditioner defrosting control method and control device and air conditioner - Google Patents

Abstract

The invention provides a defrosting control method of an air conditioner, which comprises the following steps: when the outdoor environment temperature is higher than 0 ℃ and lower than 5 ℃, the air conditioner works in a heating mode to judge whether the defrosting condition is met; if the defrosting condition is met, the air conditioner enters a defrosting mode, wherein the defrosting mode is to control the frequency of a compressor to be defrosting frequency and control the opening of an electronic expansion valve to be defrosting opening, so that the surface temperature of the outdoor heat exchanger is maintained at 0 ℃; the defrosting frequency is lower than the real-time running frequency of the compressor in the heating mode, and the defrosting opening is larger than the real-time opening of the electronic expansion valve in the heating mode; the air conditioner keeps operating in the defrosting mode until it is determined that the exit condition is satisfied. Simultaneously, the defrosting control device of the air conditioner and the air conditioner are also disclosed. According to the invention, the defrosting mode and the heating mode do not need to be switched during defrosting, and the air heat is utilized to defrost, so that the defrosting method has the advantages of low energy consumption and good user experience.

Description

A kind of air conditioner defrosting control method, control device and air conditioner

technical field

The invention relates to the technical field of air conditioning, in particular to a defrosting control method for an air conditioner, a defrosting control device for an air conditioner and an air conditioner.

Background technique

When the moisture contained in the air comes into contact with the heat transfer surface whose temperature is lower than the triple point of water, it will adhere to the heat transfer surface and form frost. The frost layer is formed by mixing ice and air. According to the research of the prior art, under the frosting condition, the frost layer on the surface of the heat exchanger will increase the heat transfer resistance and flow resistance. When the air conditioner is used in winter and works in the heating condition, due to the low outside temperature, if the air humidity reaches a certain level, the heat exchange surface of the outdoor heat exchanger of the air conditioner is easily frosted, which further seriously affects the heat exchange of the air conditioner. efficiency and service life.

The main control method for defrosting an air conditioner in the prior art is to control the air conditioner to stop the heating operation through the control system after the thickness of the frost layer reaches a certain level, adjust the working state of the four-way valve, and make the air conditioner operate in a cooling state in a short time. , make the refrigerant with higher temperature flow through the outdoor heat exchanger, increase the surface temperature of the heat transfer surface of the outdoor heat exchanger, melt the frost layer, and then re-convert to heating operation after the frost layer melts.

In the defrosting operation of the air conditioner in the prior art, during the defrosting process, since the air conditioner operates in the cooling mode for a short time, the indoor air supply temperature will be significantly reduced, resulting in an increase in the deviation between the set temperature and the ambient temperature. It increases the overall load of the device, and also affects the actual experience of the user to a certain extent.

SUMMARY OF THE INVENTION

The invention provides a defrosting control method for an air conditioner, which is used to solve the problem that the air conditioner needs to operate in a refrigeration mode for a short time during defrosting operation in the prior art, and the indoor air supply temperature is obviously lowered.

A defrosting control method for an air conditioner, comprising the following steps:

When the outdoor ambient temperature is higher than 0°C and lower than 5°C, the air conditioner works in the heating mode to determine whether the defrosting conditions are met;

If the defrosting conditions are met, the air conditioner enters the defrosting mode, in which the frequency of the compressor is controlled to be the defrosting frequency, and the opening of the electronic expansion valve is controlled to be the defrosting opening, so that the outdoor heat exchanger is The surface temperature is maintained at 0°C;

The defrosting frequency is lower than the real-time operating frequency of the compressor in the heating mode, and the defrosting opening is greater than the real-time opening of the electronic expansion valve in the heating mode;

The air conditioner keeps running in the defrost mode until it is determined that the exit condition is satisfied.

In order to solve the problem that the heat of the outdoor air is insufficient for complete defrosting when the time factor is used as the exit condition, the defrosting mode further includes controlling the rotational speed of the outdoor fan to be the first defrosting rotational speed, and the rotational speed of the indoor fan to be the second defrosting rotational speed , wherein the first defrosting speed is greater than the real-time running speed of the outdoor fan in the heating mode, and the second defrosting speed is lower than the real-time running speed of the indoor fan in the heating mode.

Preferably, the defrosting frequency is 40 Hz, and the defrosting opening is adjusted to the maximum opening of the electronic expansion valve.

Preferably, the first defrosting speed is the outdoor fan operating at the highest speed, and the second defrosting speed is the indoor fan operating at the lowest speed.

Further, the defrosting conditions include a first defrosting condition and a second defrosting condition:

The first defrosting condition is that the first defrosting condition is satisfied when the air conditioner is turned on, the compressor works according to the heating mode to satisfy the first cycle cumulatively, and the compressor continuously operates for the first time to satisfy the first period of time;

After the first defrosting condition is met, the air conditioner operates in the defrosting mode for the first time;

The second defrosting condition is that when the air conditioner operates in the defrosting mode until the exit condition is met, the air conditioner operates in the heating mode to satisfy the second cycle cumulatively and the compressor runs continuously for the first period of time, and is the same as the first time period. If the time interval of the defrost mode operation or the last operation in the defrost mode is greater than the second time period, the second defrost condition is satisfied; after the second defrost condition is satisfied, the air conditioner operates in the defrost mode again.

Further, the exit condition includes at least one of the following three:

The surface temperature of the outdoor heat exchanger is greater than the first exit temperature for a third continuous period of time;

Or, the surface temperature of the outdoor heat exchanger is greater than the second exit temperature for a fourth consecutive period;

Or, the air conditioner runs continuously for the fifth period according to the defrosting mode;

The first exit temperature is smaller than the second exit temperature.

Preferably, the defrosting mode further includes controlling the outdoor electric heater to keep in a running state.

The air conditioner defrosting control method disclosed in the present invention does not need to switch between the heating mode and the cooling mode during defrosting, the system pressure can be kept roughly stable, and compared with the prior art, the need to stabilize the system pressure is omitted. Waiting time, thus shortening the proportion of defrosting mode to the entire air conditioner operating time, and at the same time, because the four-way valve always maintains a working state, the compressor can continue to transmit the heat energy in the air to the indoor end, and at the same time utilize the heat in the environment Defrost is performed, so energy is saved and the risk of liquid hammer that can occur during conventional defrosting is eliminated.

At the same time, a defrosting control device for an air conditioner is also disclosed, comprising:

a first determination unit, configured to determine whether the operating condition of the air conditioner satisfies the defrosting condition when the outdoor ambient temperature is higher than 0°C and lower than 5°C;

The processing unit is used for controlling the air conditioner to enter the defrosting mode when the operating condition of the air conditioner meets the defrosting condition, outputting the first control signal to control the frequency of the compressor to be the defrosting frequency, and outputting the second control signal to control the electronic expansion valve The opening degree is the defrosting opening degree, so that the surface temperature of the outdoor heat exchanger is maintained at 0°C; wherein the defrosting frequency is lower than the real-time operating frequency of the compressor in the heating mode, and the defrosting opening degree is greater than all the The real-time opening of the electronic expansion valve in the heating mode;

a second determination unit, configured to determine whether the defrosting operation condition of the air conditioner satisfies the exit condition;

The switching unit is used for outputting an exit control signal to control the air conditioner to exit the defrosting mode and operate according to the set heating mode when the defrosting operation condition of the air conditioner satisfies the exit condition.

Further, when the heating operation condition of the air conditioner satisfies the defrosting condition, the processing unit simultaneously outputs a third control signal to control the rotational speed of the outdoor fan to be the first defrosting rotational speed, and control the rotational speed of the indoor fan to be the second defrosting rotational speed. rotation speed, wherein the first defrosting rotation speed is greater than the real-time rotation speed of the outdoor fan in the heating mode, and the rotation speed of the indoor fan is lower than the real-time rotation speed of the indoor fan in the heating mode.

The defrosting control device for the air conditioner disclosed in the present invention has the advantages of high defrosting control precision and no need to stop the compressor.

At the same time, an air conditioner is disclosed, including an air conditioner defrosting control device, and the air conditioner defrosting control device includes:

a first determination unit, configured to determine whether the heating operation condition of the air conditioner satisfies the defrosting condition when the outdoor ambient temperature is higher than 0°C and lower than 5°C;

The processing unit is used for controlling the air conditioner to enter the defrosting mode when the operating condition of the air conditioner meets the defrosting condition, outputting the first control signal to control the frequency of the compressor to be the defrosting frequency, and outputting the second control signal to control the electronic expansion valve The opening degree is the defrosting opening degree, so that the surface temperature of the outdoor heat exchanger is maintained at 0°C; wherein the defrosting frequency is lower than the real-time operating frequency of the compressor in the heating mode, and the defrosting opening degree is greater than all the The real-time opening of the electronic expansion valve in the heating mode;

a second determination unit, configured to determine whether the operating condition of the air conditioner satisfies the exit condition;

The switching unit is used for outputting an exit control signal to control the air conditioner to exit the defrosting mode and operate according to the set heating mode when the defrosting operation condition of the air conditioner satisfies the exit condition.

The air conditioner disclosed in the present invention has the advantages of low energy consumption and good user experience.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

FIG. 1 is a flow chart of Embodiment 1 of an air conditioner defrosting control method according to the present invention;

FIG. 2 is a flow chart of Embodiment 2 of a defrosting control method for an air conditioner according to the present invention.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

When the outdoor temperature is lower than 10°C, people usually start the air conditioner indoors and make the air conditioner work in the heating mode to increase the indoor temperature. When the air conditioner works in the heating mode, the surface temperature of the outdoor heat exchanger is lower than the outdoor dew point temperature, and the moisture in the outdoor air will condense on the surface of the outdoor heat exchanger. Through experiments, it is found that when the outdoor ambient temperature is less than 5°C, the surface of the outdoor heat exchanger begins to form frost, and it is more serious when the outdoor ambient temperature is higher than 0°C and less than 5°C. When the outdoor ambient temperature is less than 0°C, the moisture in the air will decrease, and the growth of the frost layer condensed on the surface of the outdoor heat exchanger will become slow or even stagnant. The first embodiment disclosed in the present invention aims to solve this problem on the premise of keeping the compressor working when the outdoor ambient temperature is higher than 0°C and lower than 5°C.

Specifically, as shown in FIG. 1 , the air conditioner defrosting control method provided by this embodiment includes the following steps:

When the outdoor ambient temperature is higher than 0°C and lower than 5°C, according to the user setting, the air conditioner works in the heating mode, and the controller of the air conditioner starts to determine whether the defrosting conditions are met. When the air conditioner is just turned on, the room temperature is very different from the set temperature. The heating mode preferably controls the high-frequency operation of the compressor and ensures that the compressor does not start and stop frequently within a period of time. In this way, the air conditioner makes the room temperature reach quickly. Set value to reduce discomfort. After working in the heating mode for a period of time, a frost layer will appear on the surface of the outdoor heat exchanger. When the frost layer increases to a certain thickness, the heat exchange will drop rapidly, and the evaporation pressure and evaporation temperature of the corresponding unit will begin to decrease rapidly. At the same time that the outdoor coil pressure and temperature drop, the indoor coil temperature and pressure will also begin to drop. In order to reduce the influence of the frost layer on the temperature and pressure of the coil, in this embodiment, two time factors are preferably selected as the conditions for controlling the start of the defrosting mode, that is, the cumulative working time of the compressor according to the heating mode and the first time the compressor starts Continuous run time. When the accumulated working time of the compressor according to the heating mode satisfies the first period, and the first continuous running time of the compressor satisfies the first period, it is determined that the air conditioner meets the first defrosting condition and starts defrosting. The duration of the first cycle can be set to 30 minutes to 60 minutes, and the first period is preferably set to 1 minute. The specific duration can be adjusted according to the capability and model of the air conditioner, which is not further limited here.

After entering the defrost mode, firstly control the frequency of the compressor as the defrost frequency, and control the opening of the electronic expansion valve as the defrost opening degree. The defrost frequency is lower than the real-time running frequency of the compressor in the heating mode, and the defrost The opening degree is greater than the real-time opening degree of the electronic expansion valve in the heating mode, which increases the flow of refrigerant, so that the surface temperature of the outdoor heat exchanger reaches 0°C in a very short time, making the temperature of the heat transfer surface equal to or higher than The phase transition temperature of water hinders the growth of the frost layer. At the same time, since the outdoor temperature is higher than 0°C at this time, the frost layer on the surface of the outdoor heat exchanger exchanges heat with the air, absorbs heat energy in the air, and the frost layer on the surface of the outdoor heat exchanger begins to melt. In the later stage of defrosting, the outdoor heat exchange The temperature and pressure of the device will accelerate and start to rise. In order to make the surface temperature of the outdoor heat exchanger reach 0°C in a very short time, it is preferable to reduce the defrosting frequency of the compressor to about 40 Hz in the defrosting mode, and at the same time make the defrosting opening of the electronic expansion valve to the maximum opening.

During the entire defrosting mode, the air conditioner continuously judges whether the exit conditions are met, and when the exit conditions are met, the air conditioner exits the defrosting mode and resumes the heating mode operation at the same time. However, in order to keep the compressor in the defrosting mode, it is usually preferable to start the determination after 2 minutes of operation in the defrosting mode. In this embodiment, multiple exit conditions can be set. The first type uses the coordination parameter of the time factor and the temperature factor as the exit condition, which is usually that the surface temperature of the outdoor heat exchanger is greater than the first exit temperature for the third consecutive period of time, or The surface temperature of the outdoor heat exchanger is greater than the second exit temperature for a fourth consecutive period. The preferred third time period is 60s, the fourth time period is 20s, and the first exit temperature is lower than the second exit temperature. It is not difficult to understand that both the first exit temperature and the second exit temperature are higher than 0°C. The second is to use the time factor as the exit condition, preferably when the air conditioner runs continuously according to the defrosting mode for a fifth time period, and the fifth time period is preferably 9 minutes. The first exit temperature, the second exit temperature, the third period, the fourth period and the fifth period can be adjusted according to different models.

After the air conditioner exits from the first defrost mode, the air conditioner continuously determines whether the control condition for re-entering the defrost mode, that is, the second defrost condition, is satisfied. When the accumulative operation of the air conditioner according to the heating mode satisfies the second period, the compressor continuously operates for the first period, and the time interval from the first operation in the defrost mode is greater than the second period, the second defrost condition is satisfied, and the air conditioner meets the second defrost condition. Enter the defrost mode operation again. Using time as the control condition for entering the defrosting mode, the control method is clearer, and the rapid growth of the frost layer can be effectively prevented. When the air conditioner exits the defrosting mode again, the determination is continued according to the second defrosting condition. The first period of time is preferably 1 minute.

When the air conditioner enters the defrost mode, the exit condition may only be a time factor, and there may be a situation where the heat in the outdoor air is not sufficient for complete defrosting within the time length specified by the exit condition. In this case, referring to Fig. 2, it is preferable to control the outdoor fan to work at the first defrosting speed when entering the defrosting mode, and the first defrosting speed is higher than the real-time running speed of the outdoor fan in the heating mode, preferably The maximum rotation speed increases the efficiency of heat exchange through the flow of air. Another more preferable way is to set an electric heating device in the outdoor unit, enter the defrosting mode and control the outdoor fan to work at the first defrosting speed, and control the electric heating device to start to work to accelerate the defrosting process. At the same time, in the defrosting mode, since the compressor runs at a reduced frequency, in order to ensure the user's experience, at the indoor end, the speed of the indoor fan is controlled to be the second defrosting speed, which is lower than the indoor fan in the heating mode. The real-time running speed is preferably the lowest speed, so that the temperature at the indoor end can be kept as close as possible to the indoor temperature when the heating mode is exited, so as to improve the actual experience of the user.

The air conditioner defrosting control method disclosed in the above two embodiments of the present invention does not need to switch between the heating mode and the cooling mode during defrosting, and the system pressure can be kept roughly stable, which is unnecessary compared to the prior art. The waiting time for stabilizing the system pressure is shortened, and the proportion of the defrosting mode in the entire air conditioner operating time is shortened. At the same time, because the four-way valve always maintains a working state, the compressor can continue to transport the heat energy in the air to the indoor end, while utilizing The heat in the environment is used to defrost, thus saving energy and eliminating the risk of liquid slugging that can occur in traditional defrosting processes.

The present invention also discloses a defrosting control device for an air conditioner, comprising:

a first determination unit, configured to determine whether the operating condition of the air conditioner satisfies the defrosting condition when the outdoor ambient temperature is higher than 0°C and lower than 5°C;

The processing unit is used for controlling the air conditioner to enter the defrosting mode when the operating condition of the air conditioner meets the defrosting condition, outputting the first control signal to control the frequency of the compressor to be the defrosting frequency, and outputting the second control signal to control the electronic expansion valve The opening degree is the defrosting opening degree, so that the surface temperature of the outdoor heat exchanger is maintained at 0°C; wherein the defrosting frequency is lower than the real-time operating frequency of the compressor in the heating mode, and the defrosting opening degree is greater than all the The real-time opening of the electronic expansion valve in the heating mode;

a second determination unit, configured to determine whether the defrosting operation condition of the air conditioner satisfies the exit condition;

The switching unit is used for outputting an exit control signal to control the air conditioner to exit the defrosting mode and operate according to the set heating mode when the defrosting operation condition of the air conditioner satisfies the exit condition.

Among them, the defrosting frequency is preferably 40 Hz, and the defrosting opening is preferably the maximum opening of the electronic expansion valve.

In order to optimize the defrosting effect, when the heating operating condition of the air conditioner meets the defrosting condition, the processing unit simultaneously outputs a third control signal to control the rotational speed of the outdoor fan to be the first defrosting rotational speed, and control the rotational speed of the indoor fan to be the first defrosting rotational speed. Two defrosting rotation speeds, wherein the first defrosting rotation speed is greater than the real-time rotation speed of the outdoor fan in the heating mode, and the indoor fan rotation speed is lower than the real-time rotation speed of the indoor fan in the heating mode.

In this embodiment, two time factors are preferably selected as the conditions for controlling the start of the defrosting mode, that is, the cumulative working time of the compressor according to the heating mode and the first continuous running time of the compressor. When the accumulated working time of the compressor according to the heating mode satisfies the first period, and the first continuous running time of the compressor satisfies the first period, it is determined that the air conditioner meets the first defrosting condition and starts defrosting. The duration of the first cycle can be set to 30 minutes to 60 minutes, and the first period is preferably set to 1 minute. The specific duration can be adjusted according to the capability and model of the air conditioner, which is not further limited here.

In this embodiment, multiple exit conditions can be set. The first type uses the coordination parameter of the time factor and the temperature factor as the exit condition, which is usually that the surface temperature of the outdoor heat exchanger is greater than the first exit temperature for the third consecutive period of time, or The surface temperature of the outdoor heat exchanger is greater than the second exit temperature for a fourth consecutive period. The preferred third time period is 60s, the fourth time period is 20s, and the first exit temperature is lower than the second exit temperature. It is not difficult to understand that both the first exit temperature and the second exit temperature are higher than 0°C. The second is to use the time factor as the exit condition, preferably when the air conditioner runs continuously according to the defrosting mode for a fifth time period, and the fifth time period is preferably 9 minutes. The first exit temperature, the second exit temperature, the third period, the fourth period and the fifth period can be adjusted according to different models.

After the air conditioner exits from the first defrost mode, the air conditioner continuously determines whether the control condition for re-entering the defrost mode, that is, the second defrost condition, is satisfied. When the accumulative operation of the air conditioner according to the heating mode satisfies the second period, the compressor continuously operates for the first period, and the time interval from the first operation in the defrost mode is greater than the second period, the second defrost condition is satisfied, and the air conditioner meets the second defrost condition. Enter the defrost mode operation again. Using time as the control condition for entering the defrosting mode, the control method is clearer, and the rapid growth of the frost layer can be effectively prevented. When the air conditioner exits the defrosting mode again, the determination is continued according to the second defrosting condition. The first period of time is preferably 1 minute.

The air conditioner defrosting control device disclosed in this embodiment does not need to switch between the heating mode and the cooling mode during defrosting, and the system pressure can be kept roughly stable, which eliminates the need to stabilize the system pressure compared with the prior art Therefore, the proportion of the defrosting mode in the entire air conditioner operating time is shortened. At the same time, because the four-way valve always maintains a working state, the compressor can continuously transmit the heat energy in the air to the indoor end, and at the same time utilize the ambient air. Heat defrosts, thus saving energy and eliminating the risk of liquid slugging that can occur with conventional defrosting.

The present invention also discloses an air conditioner having the above air conditioner defrosting control device. For the air conditioner defrosting control device, please refer to the detailed description of the above embodiment, and details are not repeated here. The air conditioner with the above-mentioned defrosting control device can achieve the same technical effect.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be The technical solutions described in the foregoing embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (8)

1. The defrosting control method of the air conditioner is characterized by comprising the following steps:

when the outdoor environment temperature is higher than 0 ℃ and lower than 5 ℃, the air conditioner works in a heating mode to judge whether the defrosting condition is met;

when the accumulated working time of the compressor according to the heating mode meets a first period and the first continuous running time of the compressor meets a first time interval, determining that the air conditioner meets a first defrosting condition;

the air conditioner enters a defrosting mode, wherein the defrosting mode is to control the frequency of a compressor to be defrosting frequency, control the opening of an electronic expansion valve to be defrosting opening, control the rotating speed of an outdoor fan to be a first defrosting rotating speed, and control the rotating speed of an indoor fan to be a second defrosting rotating speed, so that the surface temperature of an outdoor heat exchanger is maintained at 0 ℃;

the defrosting frequency is lower than the real-time running frequency of a compressor in the heating mode, the defrosting opening is larger than the real-time opening of an electronic expansion valve in the heating mode, the first defrosting rotating speed is larger than the real-time running rotating speed of an outdoor fan in the heating mode, and the second defrosting rotating speed is smaller than the real-time running rotating speed of an indoor fan in the heating mode;

the air conditioner keeps operating in the defrosting mode until it is determined that the exit condition is satisfied.

2. The air conditioner defrost control method of claim 1, wherein the defrost frequency is 40Hz and the defrost opening is adjusted to a maximum opening by an electronic expansion valve.

3. The air conditioner defrost control method of claim 2, wherein the first defrost speed is an outdoor fan operation at a maximum speed, and the second defrost speed is an indoor fan operation at a minimum speed.

4. The air conditioner defrost control method of any one of claims 1-3, wherein the defrost condition includes a first defrost condition and a second defrost condition:

the first defrosting condition is that the air conditioner is started, the compressor works according to the heating mode, the accumulated work meets a first period, and the first continuous operation of the compressor meets a first time interval, so that the first defrosting condition is met;

after the first defrosting condition is met, the air conditioner operates according to a defrosting mode for the first time;

the second defrosting condition is that when the air conditioner operates according to the defrosting mode until the air conditioner exits after meeting the exit condition, the air conditioner operates according to the heating mode to accumulate to meet a second period, the compressor continuously operates for a first period, and the time interval between the air conditioner and the first time of operation according to the defrosting mode or the last time of operation according to the defrosting mode is greater than a second period, the second defrosting condition is met; and after the second defrosting condition is met, the air conditioner operates according to the defrosting mode again.

5. The air conditioner defrost control method of claim 4, wherein the exit condition includes at least one of:

the surface temperature of the outdoor heat exchanger is greater than the first exit temperature for a third continuous period of time;

or, the surface temperature of the outdoor heat exchanger is greater than the second exit temperature for a fourth period of time;

or, the air conditioner continuously operates for a fifth time period according to the defrosting mode;

wherein the first exit temperature is less than the second exit temperature.

6. The air conditioner defrost control method of claim 5, wherein the defrost mode further comprises controlling an outdoor electric heater to be maintained in an operation state.

7. An air conditioner defrosting control device, comprising:

the first judging unit is used for judging whether the heating operation working condition of the air conditioner meets the defrosting condition or not when the outdoor environment temperature is higher than 0 ℃ and lower than 5 ℃; when the accumulated working time of the compressor according to the heating mode meets a first period and the first continuous running time of the compressor meets a first time interval, determining that the air conditioner meets a first defrosting condition;

the processing unit is used for controlling the air conditioner to enter a defrosting mode when the operating condition of the air conditioner meets a defrosting condition, outputting a first control signal to control the frequency of the compressor to be defrosting frequency, outputting a second control signal to control the opening degree of the electronic expansion valve to be defrosting opening degree, outputting a third control signal to control the rotating speed of the outdoor fan to be first defrosting rotating speed, and controlling the rotating speed of the indoor fan to be second defrosting rotating speed, so that the surface temperature of the outdoor heat exchanger is reduced and maintained at 0 ℃; the defrosting frequency is lower than the real-time running frequency of the compressor in the heating mode, and the defrosting opening is larger than the real-time opening of the electronic expansion valve in the heating mode; the first defrosting rotating speed is greater than the real-time rotating speed of the outdoor fan in the heating mode, and the rotating speed of the indoor fan is less than the real-time rotating speed of the indoor fan in the heating mode;

the second judging unit is used for judging whether the defrosting operation working condition of the air conditioner meets an exit condition or not;

and the switching unit is used for outputting an exit control signal to control the air conditioner to exit the defrosting mode and operate according to the set heating mode when the defrosting operation condition of the air conditioner meets the exit condition.

8. An air conditioner characterized by comprising the air conditioner defrosting control means as set forth in claim 7.

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