WO2022017546A1 - Air conditioner and control method therefor - Google Patents

Abstract

An air conditioner and a control method therefor. A first coil temperature sensor and a second coil temperature sensor are arranged on an indoor heat exchanger, the first coil temperature sensor being located at a minimum temperature position of the indoor heat exchanger when the exchanger is acting as an evaporator, and the second coil temperature sensor being located at a maximum temperature position of the indoor heat exchanger when the exchanger is acting as an evaporator. When the air conditioner is in a cooling state, a first coil temperature serves as a control parameter for the air conditioner, thus being able to ensure that the minimum temperature of the indoor heat exchanger is within a set range and not too low so to cause freezing and leakage of water. When the air conditioner is in a heating state, a second coil temperature serves as a control parameter for the air conditioner, thus being able to ensure that the maximum temperature of the indoor heat exchanger is within a set range so as to not cause a system overload.

Description

Air conditioner and control method thereof technical field

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

Background technique

The temperature control of the indoor unit of the existing air conditioner mainly includes two temperature sensors, the indoor ambient temperature and the indoor inner coil. The inner ring temperature sensor is mainly used to detect the ambient temperature, and the inner coil temperature sensor is mainly used to detect the indoor heat exchanger. The temperature detected by the inner coil temperature sensor during the cooling process is used to prevent the temperature of the indoor heat exchanger from being too low, to prevent the indoor heat exchanger from freezing and water leakage, and the temperature detected by the inner coil temperature sensor during the heating process is used to prevent The temperature of the indoor heat exchanger is too high to prevent the whole system from being overloaded.

In the existing air conditioner, there is only one coil temperature sensor of the indoor heat exchanger. In the selection of the coil temperature sensor position, the pipeline with the second lowest cooling temperature is generally selected as the coil temperature sensor position. , you can try to take into account the control of cooling and heating. The disadvantage of this method is: during the refrigeration process, if the temperature difference between the lowest temperature pipeline and the second lowest pipeline is relatively large, the temperature of the second lowest pipeline cannot represent the temperature of the evaporator. The temperature of the pipeline is too low, and the temperature detected by the inner coil temperature sensor will be relatively high, but the actual lowest point of the evaporator temperature has already frozen, which is prone to the risk of freezing and water leakage. In addition, during the heating process, the position with the second lowest cooling temperature is generally not the position with the highest temperature. If the temperature difference between the shunts of the indoor heat exchanger is large, the coil temperature sensor cannot protect and limit the maximum temperature. It may cause the system to overload and fail to protect and damage components.

The above information disclosed in this Background is only for enhancement of understanding of the background of the application and therefore it may contain that it does not form the prior art that is already known to a person of ordinary skill in the art.

technical problem

In view of the above problems existing in the prior art, the present invention provides an air conditioner and a control method thereof, so as to solve the risk of freezing and water leakage in the refrigeration process caused by the position of the coil tube of the indoor heat exchanger of the air conditioner, and the overload protection cannot be realized in the heating process technical issues.

technical solutions

In order to achieve the above-mentioned technical purpose, the present invention adopts the following technical solutions to realize:

An air conditioner, comprising an indoor heat exchanger, further comprising:

a first coil temperature sensor, located at the lowest temperature position when the indoor heat exchanger is used as an evaporator, for detecting the temperature of the first coil;

The second coil temperature sensor is located at the highest temperature position when the indoor heat exchanger is used as a condenser, and is used to detect the temperature of the second coil;

The control module is used to obtain the cooling and heating state of the air conditioner, in the cooling state, the temperature of the first coil is used as the control parameter of the air conditioner, and in the heating state, the temperature of the second coil is used as the air conditioner control parameters of the controller.

In the air conditioner as described above, the control module is configured to use the temperature of the first coil as the control parameter of the air conditioner within a period of time after the start of the cooling state, and within a period of time after the start of the heating state The temperature of the second coil is used as a control parameter of the air conditioner; it is also used to select the temperature of the first coil or the temperature of the second coil according to the difference between the temperature of the first coil and the temperature of the second coil after a period of time when the cooling state starts The temperature is used as the control parameter of the air conditioner, and the temperature of the first coil is selected as the control parameter of the air conditioner according to the difference between the temperature of the first coil and the temperature of the second coil after the heating state starts for a period of time.

In the air conditioner as described above, the control module is configured to select the temperature of the first coil as the temperature of the air conditioner when -a < temperature of the first coil - temperature of the second coil≤0 Control parameter, when 0<first coil temperature-second coil temperature<a, the second coil temperature is selected as the control parameter of the air conditioner; it is used after heating starts for a period of time, when -a<th When the temperature of the first coil - the temperature of the second coil is less than or equal to 0, the temperature of the second coil is selected as the control parameter of the air conditioner, and when 0 < the temperature of the first coil - the temperature of the second coil <a, the first coil is selected The temperature is used as the control parameter of the air conditioner.

In the above-mentioned air conditioner, the control module is configured to determine that the air conditioner operates abnormally when |first coil temperature-second temperature|≥a after cooling or heating starts for a period of time.

In the air conditioner as described above, the control module is used to control the opening degree of the electronic expansion valve according to the control parameter in the cooling state; the control module is used to control the opening of the compressor according to the control parameter in the heating state. operating frequency.

A control method of an air conditioner, the method is:

A first coil temperature sensor located at the lowest temperature position of the indoor heat exchanger as an evaporator detects the temperature of the first coil;

A second coil temperature sensor located at the highest temperature position of the indoor heat exchanger as a condenser detects the temperature of the second coil;

In the cooling state, the temperature of the first coil is used as the control parameter of the air conditioner, and in the heating state, the temperature of the second coil is used as the control parameter of the air conditioner.

The above-mentioned control method of an air conditioner uses the temperature of the first coil as the control parameter of the air conditioner within a period of time after the start of the cooling state, and uses the temperature of the second coil within a period of time after the start of the heating state. The temperature of the tube is used as the control parameter of the air conditioner; after a period of time when the cooling state starts, the temperature of the first coil or the temperature of the second coil is selected as the air conditioner according to the difference between the temperature of the first coil and the temperature of the second coil. The first coil temperature is selected as the control parameter of the air conditioner according to the difference between the first coil temperature and the second coil temperature after a period of time when the heating state starts.

In the control method of the air conditioner as described above, after a period of time after the start of cooling, when -a < temperature of the first coil - temperature of the second coil ≤ 0, the temperature of the first coil is selected as the control parameter of the air conditioner, When 0<first coil temperature-second coil temperature<a, select the second coil temperature as the control parameter of the air conditioner; after heating for a period of time, at -a<first coil temperature- When the second coil temperature≤0, the second coil temperature is selected as the control parameter of the air conditioner, and when 0<first coil temperature-second coil temperature<a, the first coil temperature is selected as the air conditioner control parameters of the controller.

In the above-mentioned control method of an air conditioner, after a period of time after cooling or heating starts, and when |first coil temperature-second temperature|≥a, it is determined that the air conditioner is operating abnormally.

In the above-mentioned control method of an air conditioner, the opening degree of the electronic expansion valve is controlled by the control parameter in the cooling state, and the operating frequency of the compressor is controlled by the control parameter in the heating state.

beneficial effect

Compared with the prior art, the advantages and positive effects of the present invention are: the air conditioner of the present invention is provided with a first coil temperature sensor and a second coil temperature sensor on the indoor heat exchanger, and the first coil temperature sensor is located in the indoor heat exchanger. When the heat exchanger is used as the evaporator, the temperature is the lowest position. The second coil temperature sensor is located at the highest temperature position when the indoor heat exchanger is used as the condenser. When the air conditioner is in the cooling state, the first coil temperature is used as the control parameter of the air conditioner. , it can ensure that the minimum temperature of the indoor heat exchanger is within the set range, and it will not cause freezing and water leakage. The maximum temperature of the heat exchanger is within the set range, and the system will not be overloaded.

The control method of the air conditioner of the present invention uses the temperature of the first coil located at the lowest position of the indoor heat exchanger temperature as the control parameter of the air conditioner when the air conditioner is in a cooling state, which can ensure that the lowest temperature of the indoor heat exchanger is within the set range. When the air conditioner is in the heating state, the temperature of the second coil located at the highest position of the indoor heat exchanger temperature is used as the control parameter of the air conditioner, which can ensure the highest temperature of the indoor heat exchanger. Within the set range, the system will not be overloaded.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the embodiments. Obviously, the drawings in the following description are some embodiments of the present invention. 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 schematic block diagram of an air conditioner according to a specific embodiment of the present invention.

FIG. 2 is a flowchart of a control method of an air conditioner according to a specific embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principle of the present invention, and are not intended to limit the protection scope of the present invention.

It should be noted that in the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The terminology of the indicated direction or positional relationship is based on the direction or positional relationship shown in the drawings, which is only for convenience of description and does not indicate or imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation , so it should not be construed as a limitation of the present invention. Furthermore, the terms "first", "second", and "third" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

In addition, it should also be noted that, in the description of the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a It is a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication between two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

The refrigeration cycle system of the air conditioner in this embodiment is in the prior art, and will not be described here. The focus of this embodiment is to set two independent coil temperature sensors on the indoor heat exchanger, and to design the positions of the coil temperature sensors, so as to select a suitable coil temperature sensor to detect the temperature in the cooling state and the heating state. The temperature is used as a control parameter to control the air conditioner.

In the air conditioner and the control method thereof in this embodiment, a first coil temperature sensor and a second coil temperature sensor are arranged on the indoor heat exchanger, and the first coil temperature sensor is located at the lowest temperature position when the indoor heat exchanger is used as an evaporator , the second coil temperature sensor is located at the highest temperature position when the indoor heat exchanger is used as a condenser. When the air conditioner is in the cooling state, the first coil temperature is used as the control parameter of the air conditioner, which can ensure the lowest temperature of the indoor heat exchanger. Within the set range, it will not cause freezing and water leakage. When the air conditioner is in the heating state, the temperature of the second coil is used as the control parameter of the air conditioner to ensure that the maximum temperature of the indoor heat exchanger is within the set range. In this case, the system will not be overloaded, and this embodiment can ensure the normal operation of the air conditioner.

Specifically, as shown in FIG. 1 , the air conditioner of this embodiment includes an indoor heat exchanger, a control module, a first coil temperature sensor and a second coil temperature sensor located in the indoor heat exchanger.

The first coil temperature sensor is located at the lowest temperature position when the indoor heat exchanger is used as the evaporator, and is used for detecting the first coil temperature at the lowest temperature position. Wherein, the lowest temperature position is the lowest temperature position when the air conditioner is in a normal working state determined in advance through experiments.

The second coil temperature sensor is located at the highest temperature position when the indoor heat exchanger is used as a condenser, and is used to detect the second coil temperature at the highest temperature position. The highest temperature position is the highest temperature position when the air conditioner is in a normal working state determined by experiments in advance.

The control module is used to obtain the cooling and heating state of the air conditioner. When the air conditioner is in a cooling state, the indoor heat exchanger is an evaporator, and when the air conditioner is in a heating state, the indoor heat exchanger is a condenser. Generally, the air conditioner is in the cooling or heating state by directly receiving the control signal.

The controller is configured to use the temperature of the first coil as the control parameter of the cooling state in the cooling state, and use the temperature of the second coil as the control parameter of the heating state in the heating state.

In general, the air conditioner is in normal operation at the initial stage of operation, that is, in the cooling state, the temperature of the first coil is the lowest point of the temperature of the entire indoor heat exchanger, and in the heating state, the temperature of the second coil is the temperature of the entire indoor heat exchanger. The highest point of the heater temperature. However, after the air conditioner runs for a period of time, the temperature of the indoor heat exchanger may change due to some reasons such as liquid separation. At this time, it is necessary to select a more appropriate control according to the relationship between the temperature of the first coil and the temperature of the second coil. parameters to facilitate the control of the air conditioner.

Specifically, the control module is configured to use the temperature of the first coil as the control parameter of the cooling state within a period of time after the start of the cooling state, and use the temperature of the second coil as the heating state within a period of time after the start of the heating state It is also used to select the temperature of the first coil or the temperature of the second coil as the control parameter of the cooling state according to the difference between the temperature of the first coil and the temperature of the second coil after the cooling state starts for a period of time. After the heating state starts for a period of time, the temperature of the first coil is selected as the control parameter of the heating state according to the difference between the temperature of the first coil and the temperature of the second coil.

Further, the control module is used to select the first coil temperature as the control parameter of the cooling state when -a<first coil temperature-second coil temperature≤0 after cooling starts for a period of time, and when 0<first coil temperature When the coil temperature - the second coil temperature < a, the second coil temperature is selected as the control parameter of the cooling state; it is used for -a < the first coil temperature - the second coil temperature after the heating starts for a period of time. When ≤0, the temperature of the second coil is selected as the control parameter of the heating state, and when 0<the temperature of the first coil - the temperature of the second coil<a, the temperature of the first coil is selected as the control parameter of the heating state. Wherein, a is a natural number, preferably a is any value in 5-9.

The control module is also used to judge that the air conditioner is running abnormally (indicating that the amount of refrigerant is insufficient or that there is a problem with liquid separation) after a period of time after the cooling or heating starts, and when |the first coil temperature - the second temperature| Prompt or alarm information to remind relevant personnel to deal with it.

Among them, the temperature control parameters in the cooling state are mainly used to control the throttling opening of the electronic expansion valve and the refrigeration and freezing protection when the air conditioner is in the cooling state, and the heating state control parameters are mainly used for the overload protection of the indoor unit when the air conditioner is in the heating state. .

The control module is used for controlling the opening degree of the electronic expansion valve according to the temperature control parameter in the cooling state in the cooling state.

When the air conditioner is running, when the cooling control signal is received, within a period of time, the temperature detected by the first coil temperature sensor is preferentially selected as the temperature control parameter in the cooling state to participate in the throttle opening control of the electronic expansion valve. During the process, the inner first coil temperature sensor with low temperature is used as the reference. After a period of time, the lower temperature of the first coil temperature and the second coil temperature is selected as the temperature control parameter in the cooling state to participate in the throttle opening control of the electronic expansion valve.

The temperature control parameters in the cooling state control the throttling of the electronic expansion valve as follows:

The air conditioner has different target superheat degrees at different compressor frequencies, and the target superheat degree is the parameter T solidified into the air conditioner. During the actual operation of the air conditioner, the difference between the compressor suction temperature Ts and the temperature control parameter Ta in the cooling state is the actual superheat degree T1=(Ts-Ta), and the difference between the target superheat degree T and the actual superheat degree T1 is T -T1, the electronic expansion valve opening is adjusted according to this difference. After the air conditioner is turned on and the compressor runs for t minutes, the opening of the electronic expansion valve is fixed. After t minutes, the value of T-T1 will be judged, and the detection will be performed every specific time t1.

Control the speed of electronic expansion valve adjustment according to the interval of T-T1:

When T-T1=0, the opening of the electronic expansion valve is not adjusted.

When T-T1>0, the larger the interval to which T-T1 belongs, the greater the speed of the electronic expansion valve adjustment, the smaller the interval to which T-T1 belongs, and the smaller the speed of the electronic expansion valve adjustment.

When T-T1 < 0, the larger the interval to which T-T1 belongs, the smaller the speed of electronic expansion valve adjustment is, and the smaller the interval to which T-T1 belongs, the greater the speed of electronic expansion valve adjustment.

For example:

5＜T-T1, electronic expansion valve opening -20pls (step)/s;

3＜T-T1≤5, electronic expansion valve opening -10 pls (step)/s;

1＜T-T1≤3, electronic expansion valve opening -5 pls (step)/s;

0＜T-T1≤1, electronic expansion valve opening -2 pls (step)/10s;

T-T1=0, the opening of the electronic expansion valve is 0 pls (step)/10s;

-1≤T-T1＜0, electronic expansion valve opening +2 pls (step)/10s;

-3≤T-T1＜-1, electronic expansion valve opening +5 pls (step)/s;

-5≤T-T1＜-3, electronic expansion valve opening +10pls (step)/s;

-5>T-T1, electronic expansion valve opening +20pls (step)/s.

The control module is used for controlling the operating frequency of the compressor according to the temperature control parameter in the heating state in the heating state.

When the air conditioner is running, when a heating control signal is received, within a period of time, the temperature detected by the second coil temperature sensor is preferentially used as a heating state temperature control parameter to control the compressor. After a period of time, the higher temperature of the first coil temperature and the second coil temperature is selected as the temperature control parameter in the heating state to control the compressor.

During the heating process, the temperature control parameter Tb in the heating state is only used for overload protection. The frequency of the compressor is controlled according to the interval to which Tb belongs. The higher the Tb, the faster the compressor frequency reduction speed. When Tb reaches the upper limit of the set value, the compressor will stop for protection, and the compressor will restart when Tb drops to the set value.

For example:

When Tb≥68℃, press shutdown protection.

When 68℃＞Tb≥65℃, press frequency -10Hz/s;

When 65℃＞Tb≥63℃, press frequency -1Hz/s;

When 63℃＞Tb≥61℃, the frequency of the press is 0Hz/s;

After compressor shutdown protection, the compressor restarts after Tb temperature is lower than 58℃.

This embodiment also proposes a control method for the air conditioner:

The first coil temperature sensor located at the lowest temperature position of the indoor heat exchanger as the evaporator detects the temperature of the first coil;

The second coil temperature sensor located at the highest temperature position of the indoor heat exchanger as a condenser detects the temperature of the second coil;

In the cooling state, the temperature of the first coil is used as the control parameter of the air conditioner, and in the heating state, the temperature of the second coil is used as the control parameter of the air conditioner.

Further, within a period of time after the start of the cooling state, the temperature of the first coil is used as the control parameter of the air conditioner, and within a period of time after the start of the heating state, the temperature of the second coil is used as the control parameter of the air conditioner; After the cooling state starts for a period of time, the temperature of the first coil or the temperature of the second coil is selected as the control parameter of the air conditioner according to the difference between the temperature of the first coil and the temperature of the second coil. The difference between the temperature of the first coil and the temperature of the second coil selects the temperature of the first coil as a control parameter of the air conditioner.

Further, after a period of time after the cooling starts, when -a<first coil temperature-second coil temperature≤0, select the first coil temperature as the control parameter of the air conditioner, and when 0<first coil temperature - When the temperature of the second coil is < a, select the temperature of the second coil as the control parameter of the air conditioner; after a period of time after the heating starts, select the temperature of the second coil when - a < the temperature of the first coil - the temperature of the second coil ≤ 0 The temperature of the second coil is used as the control parameter of the air conditioner, and when 0<the temperature of the first coil - the temperature of the second coil <a, the temperature of the first coil is selected as the control parameter of the air conditioner.

After a period of time after cooling or heating starts, and when |the first coil temperature - the second temperature|≥a, it is judged that the air conditioner is operating abnormally, and a prompt or alarm message is output.

In the cooling state, the opening degree of the electronic expansion valve is controlled by the control parameter, and in the heating state, the operating frequency of the compressor is controlled by the control parameter. The specific control method is as described above and will not be repeated here.

As shown in Figure 2, the control method of this embodiment includes the following steps:

S1. Turn on the device, if it is a cooling signal, go to step S2, if it is a heating signal, go to step S7.

S2. Receive a cooling signal.

S3. The temperature of the first coil is used as a control parameter.

S4. After a period of time, determine the difference between the temperature of the first coil and the temperature of the second coil, if 0<A-B<7, go to step S5, if -7<A-B≤0, go to step S3, otherwise go to step S6.

S5. The temperature of the second coil is used as a control parameter.

S6, abnormal.

S7. Receive a heating signal.

S8, taking the temperature of the second coil as a control parameter.

S9. After a period of time, determine the difference between the temperature of the first coil and the temperature of the second coil. If 0<A-B<7, go to step S10, if -7<A-B≤0, go to step S8, otherwise go to step S6.

S10, taking the temperature of the first coil as a control parameter.

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 can still The recorded technical solutions 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 claimed in the present invention.

Claims (10)

1. An air conditioner, comprising an indoor heat exchanger, is characterized in that, further comprising:

   a first coil temperature sensor, located at the lowest temperature position when the indoor heat exchanger is used as an evaporator, for detecting the temperature of the first coil;

   The second coil temperature sensor is located at the highest temperature position when the indoor heat exchanger is used as a condenser, and is used to detect the temperature of the second coil;

   The control module is used to obtain the cooling and heating state of the air conditioner, in the cooling state, the temperature of the first coil is used as the control parameter of the air conditioner, and in the heating state, the temperature of the second coil is used as the air conditioner control parameters of the controller.
2. The air conditioner according to claim 1, wherein the control module is configured to use the first coil temperature as a control parameter of the air conditioner within a period of time after the cooling state starts, and start the heating state in the heating state The temperature of the second coil is used as the control parameter of the air conditioner for a period of time after that; it is also used to select the first disk according to the difference between the temperature of the first coil and the temperature of the second coil after a period of time after the cooling state starts The temperature of the tube or the temperature of the second coil is used as the control parameter of the air conditioner. After a period of time when the heating state starts, the temperature of the first coil is selected as the air conditioner according to the difference between the temperature of the first coil and the temperature of the second coil. control parameters of the controller.
3. The air conditioner according to claim 2, wherein the control module is configured to select the first coil when -a<first coil temperature-second coil temperature≤0 after cooling starts for a period of time The temperature is used as the control parameter of the air conditioner. When 0<first coil temperature-second coil temperature<a, the second coil temperature is selected as the control parameter of the air conditioner; it is used for a period of time when heating starts Then, when -a<first coil temperature-second coil temperature≤0, select the second coil temperature as the control parameter of the air conditioner, and when 0<first coil temperature-second coil temperature< In case a, the temperature of the first coil is selected as the control parameter of the air conditioner.
4. The air conditioner according to claim 3, wherein the control module is configured to determine the temperature of the first coil after a period of time after the start of cooling or heating and when |the first coil temperature - the second temperature|≥a The air conditioner is operating abnormally.
5. The air conditioner according to claims 1-4, wherein the control module is used to control the opening of the electronic expansion valve according to the control parameter in a cooling state; the control module is used in a heating state The operating frequency of the compressor is controlled according to the control parameter.
6. A control method for an air conditioner, characterized in that the method is:

   A first coil temperature sensor located at the lowest temperature position of the indoor heat exchanger as an evaporator detects the temperature of the first coil;

   A second coil temperature sensor located at the highest temperature position of the indoor heat exchanger as a condenser detects the temperature of the second coil;

   In the cooling state, the temperature of the first coil is used as the control parameter of the air conditioner, and in the heating state, the temperature of the second coil is used as the control parameter of the air conditioner.
7. The control method of an air conditioner according to claim 6, wherein the temperature of the first coil is used as the control parameter of the air conditioner within a period of time after the start of the cooling state, and the temperature of the first coil is used as the control parameter of the air conditioner within a period of time after the start of the cooling state, and the temperature of the first coil is used as the control parameter of the air conditioner within a period of time after the start of the cooling state, The temperature of the second coil is used as the control parameter of the air conditioner within the time period; after a period of time when the cooling state starts, the temperature of the first coil or the temperature of the second coil is selected according to the difference between the temperature of the first coil and the temperature of the second coil The tube temperature is used as the control parameter of the air conditioner, and the first coil temperature is selected as the control parameter of the air conditioner according to the difference between the first coil temperature and the second coil temperature after the heating state starts for a period of time.
8. The control method of an air conditioner according to claim 7, characterized in that, after a period of time after cooling starts, when -a<first coil temperature-second coil temperature≤0, the temperature of the first coil is selected as the temperature of the first coil. The control parameter of the air conditioner, when 0<first coil temperature-second coil temperature<a, select the second coil temperature as the control parameter of the air conditioner; after heating for a period of time, at -a When <the first coil temperature - the second coil temperature≤0, the second coil temperature is selected as the control parameter of the air conditioner, and when 0<the first coil temperature - the second coil temperature<a, the first coil temperature is selected. The coil temperature is used as a control parameter of the air conditioner.
9. The control method of an air conditioner according to claim 8, characterized in that, after a period of time after cooling or heating starts, and when |the first coil temperature - the second temperature|≥a, it is determined that the air conditioner is running abnormal.
10. The control method for an air conditioner according to any one of claims 6-9, wherein the control parameter is used to control the opening of the electronic expansion valve in a cooling state, and the control parameter is used in a heating state to control The operating frequency of the compressor.