WO2021223531A1 - Air conditioner and control method therefor - Google Patents

Abstract

A control method for an air conditioner, comprising: acquiring an outdoor ambient temperature, an indoor ambient temperature, an outdoor relative air humidity, and an external coil temperature; according to the outdoor ambient temperature and the outdoor relative air humidity, determining a dew-point temperature under outdoor environmental conditions; according to the outdoor ambient temperature and the dew-point temperature under the outdoor environmental conditions, determining a target external coil temperature; comparing the target external coil temperature with the external coil temperature; and according to a comparison result and the indoor ambient temperature, adjusting operation parameters of an air conditioner. Further provided is an air conditioner for executing the control method. The air conditioner and the control method therefor achieve heating without frosting of an air conditioner, improving the user experience.

Description

Air conditioner and its control method Technical field

The invention belongs to the technical field of air conditioners, and specifically relates to an air conditioner and a control method thereof.

Background technique

As people's living standards are getting higher and higher, the use of air conditioners is becoming more and more common. The cooling or heating process of the air conditioner is actually a process of heat exchange. In the heating process, the outdoor condenser absorbs heat from the outdoor space, and then transfers the heat to the indoor space through the air conditioning system to release heat. In this process, when the surface temperature of the outdoor heat exchanger is lower than the dew point temperature of the air, water vapor in the air will condense on the ice surface of the outdoor heat exchanger, and frost will form. Frosting will cause the heat exchanger to increase in resistance and reduce the amount of air that can be used to exchange heat with the refrigerant. This will inevitably hinder the heat transfer capacity of the outdoor heat exchanger, thereby affecting the comfort of the air conditioner. The current solution is usually to convert the operating mode of the air conditioner into a cooling and defrosting mode when defrosting is required, so as to remove the frost adhering to the surface of the outdoor heat exchanger.

However, the above cooling and defrosting mode needs to stop heating during operation, which will inevitably cause the temperature of the indoor space to drop during the defrosting period, resulting in room temperature fluctuations, and resulting in poor user experience. In addition, since the cooling and defrosting process consumes electric energy, but cannot provide heat to the indoor space, it will cause energy waste.

Correspondingly, a new technical solution is needed in this field to solve the above-mentioned problems.

Summary of the invention

In order to solve the above-mentioned problems in the prior art, that is, to solve the problem of the temperature drop of the indoor space caused by the defrosting of the existing air conditioner, one aspect of the present invention provides a control method of an air conditioner, the control method includes: Outdoor ambient temperature Tao, indoor ambient temperature Tai, outdoor air relative humidity φ, and external coil temperature Tc; according to the outdoor ambient temperature Tao and the outdoor air relative humidity φ, determine the dew point temperature Tdp under outdoor environmental conditions; The outdoor ambient temperature Tao and the dew point temperature Tdp under the outdoor ambient conditions determine the target outer coil temperature Tct; compare the target outer coil temperature Tct with the outer coil temperature Tc; according to the comparison result and the indoor The ambient temperature Tai adjusts the operating parameters of the air conditioner.

In the preferred technical solution of the above control method, the air conditioner includes an indoor unit and an outdoor unit, the indoor unit includes an indoor fan and an auxiliary heating device, the outdoor unit includes a compressor, an outdoor fan, and a throttling device. The operating parameters of the air conditioner include one or more of the operating frequency of the compressor, the rotational speed of the outdoor fan, the rotational speed of the indoor fan, the opening of the throttle device, and the operating state of the auxiliary heating device.

In the preferred technical solution of the above control method, the “compare the target outer coil temperature Tct with the outer coil temperature Tc; adjust the operating parameters of the air conditioner according to the comparison result and the indoor ambient temperature Tai "Including: when the indoor ambient temperature Tai<the set temperature Ts-1, and: Tc>Tct+1, the operating frequency of the compressor is increased, and the rotation speed of the outdoor fan remains unchanged, selective Adjust the opening of the throttling device, the rotation speed of the indoor fan and/or the operating state of the auxiliary heating device; when Tct-1≤Tc≤Tct+1, the operating frequency of the compressor is set to The rotation speed of the outdoor fan increases, and the opening degree of the throttling device, the rotation speed of the indoor fan and/or the operating state of the auxiliary heating device are selectively adjusted.

In the preferred technical solution of the above control method, the “compare the target outer coil temperature Tct with the outer coil temperature Tc; adjust the operating parameters of the air conditioner according to the comparison result and the indoor ambient temperature Tai "Including: when the set temperature Ts-1≤the indoor ambient temperature Tai≤the set temperature Ts+1, and: Tc>Tct+1, keep the operating frequency of the compressor unchanged, and make the outdoor The rotation speed of the fan is reduced, and the opening of the throttling device, the rotation speed of the indoor fan and/or the operating state of the auxiliary heating device are selectively adjusted; when Tct-1≤Tc≤Tct+1, the The operating frequency of the compressor and the rotation speed of the outdoor fan remain unchanged, and the opening degree of the throttling device, the rotation speed of the indoor fan and/or the operating state of the auxiliary heating device are selectively adjusted.

In the preferred technical solution of the above control method, the “compare the target outer coil temperature Tct with the outer coil temperature Tc; adjust the operating parameters of the air conditioner according to the comparison result and the indoor ambient temperature Tai "Includes: turning on the auxiliary heating device and/or reducing the rotational speed of the indoor fan.

In the preferred technical solution of the above control method, the “compare the target outer coil temperature Tct with the outer coil temperature Tc; adjust the operating parameters of the air conditioner according to the comparison result and the indoor ambient temperature Tai "It also includes: acquiring the current exhaust temperature Td; comparing the current exhaust temperature Td with the target exhaust temperature Tdt, and adjusting the opening degree of the throttle device according to the comparison result.

In the preferred technical solution of the above control method, the “compare the target outer coil temperature Tct with the outer coil temperature Tc; adjust the operating parameters of the air conditioner according to the comparison result and the indoor ambient temperature Tai "Including: when Tc<Tct-1, adjust the operating parameters of the air conditioner as follows: increase the speed of the outdoor fan; selectively according to the comparison result of the current exhaust temperature Td and the target exhaust temperature Tdt Adjusting the opening degree of the throttling device; and selectively adjusting the operating frequency of the compressor, the rotating speed of the indoor fan, and/or the operating state of the auxiliary heating device.

In the preferred technical solution of the above control method, the "determining the dew point temperature Tdp under outdoor environmental conditions according to the outdoor ambient temperature Tao and the outdoor air relative humidity φ" specifically includes: determining the outdoor environmental conditions according to the following formula Lower dew point temperature Tdp: Tdp=(C ₁ φ ² +C ₂ φ+C ₃ )×Tao-(C ₄ φ ² +C ₅ φ+C ₆ ), where C ₁ , C ₂ , C ₃ , C _4. C ₅ and C ₆ are coefficients, Tao is the outdoor environmental temperature, φ is the outdoor environmental relative humidity, and Tdp is the dew point temperature under outdoor environmental conditions.

In the preferred technical solution of the above control method, the "determining the target outer coil temperature Tct according to the outdoor ambient temperature Tao and the dew point temperature Tdp under outdoor environmental conditions" specifically includes: if the dew point temperature Tdp under outdoor environmental conditions is Is greater than or equal to the first preset value t ₁ , the target outer coil temperature Tct is determined according to the following formula: Tct=A ₁ *Tdp; if the dew point temperature Tdp under outdoor environmental conditions is less than the first preset value t ₁ , then The target outer coil temperature Tct is determined according to the following formula: Tct=Tdp+t ₂ ; where A ₁ is a coefficient, and t ₁ and t ₂ are coefficients.

Those skilled in the art can understand that in the new technical solution, the control method of the air conditioner is specifically as follows: first obtain the indoor ambient temperature Tai, outdoor ambient temperature Tao, outer coil temperature Tc and outdoor air relative humidity φ, and then according to Outdoor environmental temperature Tao and outdoor air relative humidity φ can determine the dew point temperature Tdp under outdoor environmental conditions, and then determine the target outer coil temperature Tct according to the dew point temperature Tdp under the outdoor environmental conditions and outdoor ambient temperature Tao. Coil temperature Tct and outer coil temperature Tc, make the outer coil temperature Tc greater than or equal to the target outer coil temperature Tct to achieve no frosting and combine the indoor ambient temperature according to the comparison result, such as the indoor ambient temperature and user requirements Compared with the set temperature, it can satisfy the air conditioner's continuous heating without frosting control. In this way, the adjustment is made under the premise of comprehensively considering the relationship between the outer coil temperature and the target outer coil temperature and the indoor ambient temperature. The operating parameters of the air conditioner can also realize the continuous heating operation of the air conditioner while ensuring that the air conditioner does not form frost, so that there is no need to cool down and defrost, thus effectively improving the user experience and avoiding energy waste caused by the defrosting process. , So as to achieve the purpose of energy saving. The operating parameters of the air conditioner can be the operating frequency of the compressor, the speed of the outdoor fan, the opening of the throttle device, the switch and output ratio of the indoor auxiliary electric heating, or the speed of the indoor fan, etc.

It should be noted that the condenser of the outdoor unit includes an upper coil and a lower coil. In the control process, the coil temperature of the upper coil and the lower coil is usually taken as the actual outer coil temperature in the present invention. Tc.

In a preferred technical solution of the present invention, the air conditioner includes an indoor unit and an outdoor unit, the indoor unit includes an indoor fan, the outdoor unit includes a compressor, an outdoor fan, and a throttling device, and the operating parameters of the air conditioner include the operation of the compressor. One or more of the frequency, the rotation speed of the outdoor fan, the rotation speed of the indoor fan, the opening of the auxiliary heating device and the throttling device, for example, can be based on the indoor ambient temperature and the set temperature, the inner coil temperature and the target outer disk Tube temperature comparison results to adjust the compressor operating frequency, or compressor operating frequency and outdoor fan speed, or outdoor fan speed and indoor fan speed, or compressor operating frequency, outdoor fan speed, indoor fan Through the adjustment of the above-mentioned one or two or other operating parameters, the rotation speed of the auxiliary heating device and the opening degree of the throttling device, etc., can achieve continuous heating while ensuring that the air conditioner does not form frost during operation.

Furthermore, when Tai<Ts-1 (Tai is the indoor ambient temperature, Ts is the set temperature), the indoor ambient temperature Tai is lower than the set temperature Ts, and thus the air conditioner is required to heat to increase the temperature of the indoor space. And further adjust the operating parameters of the air conditioner according to the comparison result of the outer coil temperature and the target outer coil temperature, so as to achieve continuous heating while preventing the outer coil from frosting. Specifically, when Tc>Tct+1 (Tc is the outer coil temperature, Tct is the target outer coil temperature), the temperature of the outer coil is higher at this time, which increases the operating frequency of the compressor and makes the outdoor fan The rotation speed remains the same, so that the refrigerant circulation of the air conditioner can be increased, and the air volume of the outdoor fan remains unchanged. The heat provided to the indoor unit comes from the outdoor air, which ensures that the heating capacity is not reduced, thereby ensuring However, due to the increase in the amount of refrigerant and the decrease in the air volume of the outdoor fan, the amount of air that can exchange heat with a unit amount of refrigerant is reduced, which will also cause the temperature of the refrigerant to decrease, thereby reducing the temperature of the refrigerant. The temperature of the outer coil is reduced, so that the temperature of the outer coil can be reduced without reducing the speed of the outdoor fan; when Tct-1≤Tc≤Tct+1, the temperature of the outer coil is moderate, so that the compression The operating frequency of the unit and the rotation speed of the outdoor fan increase, so that the circulation of the refrigerant and the air volume of the outdoor fan also increase, so that the heat that can be provided to the indoor unit increases, and the heating purpose can be achieved. An increase in the amount of heat may cause a decrease in the temperature of the outer coil, but an increase in the air volume of the outdoor fan will also increase the amount of outdoor air that can exchange heat with the refrigerant, and improve the heat exchange efficiency between the refrigerant and the outdoor air, thereby ensuring the refrigerant The temperature of the outer coil is basically unchanged, which can ensure that the temperature of the outer coil is continuously in a relatively moderate range to ensure no frost; when Tc<Tct-1, the temperature of the outer coil is lower at this time, and there is frost It is possible to increase the speed of the outdoor fan, which also increases the air volume of the outdoor fan, that is, increases the amount of air that can exchange heat with the refrigerant, thus ensuring the heating capacity required by the indoor unit to meet In order to meet the heating requirements, the increase of the outdoor fan air volume can improve the heat exchange efficiency between the refrigerant and the outdoor air, which can also increase the temperature of the refrigerant, thereby increasing the temperature of the outer coil, thereby ensuring heating and increasing The temperature of the outer coil is to ensure no frost. Obviously, while increasing the speed of the outdoor fan, you can also adjust the opening of the throttling device. When the speed of the outdoor fan rises to the maximum speed of the outdoor fan, Tc is still less than Tct -1, the operating frequency of the compressor can be appropriately reduced, so that the circulation of the refrigerant can be reduced, and the temperature of the refrigerant can be further increased under the premise that the outdoor air volume increases, so as to better ensure heating while not frost.

Furthermore, when Ts-1≤Tai≤Ts+1, the indoor ambient temperature Tai is relatively moderate. At this time, there is no need to specifically adjust the indoor ambient temperature. It is only necessary to ensure that the outer coil does not form frost during the heating process of the air conditioner. That's it. Specifically, when Tc>Tct+1, the temperature of the outer coil is higher than the target outer coil temperature, so that the operating frequency of the compressor remains unchanged and the speed of the outdoor fan is reduced, thus reducing the heat exchange with the refrigerant. The amount of outdoor air, the temperature of the refrigerant will drop, thereby reducing the temperature of the outer coil, and lowering the temperature of the outer coil increases the heat exchange temperature difference between the outdoor air and the refrigerant, and the difference between the outdoor air and the refrigerant The amount of heat exchange between the room is positively correlated with the product of the air volume of the outdoor air and the heat exchange temperature difference, so that the heating capacity can be ensured while ensuring no frost, so that the indoor ambient temperature continues to be in a relatively moderate range. However, if only reducing the speed of the outdoor fan cannot achieve the purpose of lowering the temperature of the outer coil, the operating frequency of the compressor can be increased slowly, which can ensure heating capacity and prevent frost. When Tct-1≤Tc≤Tct+1, the temperature of the outer coil is relatively moderate, and the temperature of the indoor environment is relatively moderate at this time, so there is no need to adjust the operating parameters of the air conditioner and keep the original operating state. When Tc<Tct-1, the temperature of the outer coil is lower at this time, and there is the possibility of frost, which will increase the speed of the outdoor fan, which can increase the air volume of the outdoor fan, thus ensuring No frosting while heating. Obviously, while increasing the speed of the outdoor fan, the opening of the throttling device can also be appropriately adjusted. When the speed of the outdoor fan rises to the maximum speed of the outdoor fan, Tc is still less than Tct-1, which can appropriately reduce the operation of the compressor Frequency so as to better prevent frosting while the air conditioner is heating.

Further, in order to ensure that the air conditioner does not form frost and does not affect the heating function of the air conditioner, the auxiliary heating device is turned on to provide an additional heat source for the indoor space, so as to ensure that the air conditioner can continue heating. And/or reduce the rotation speed of the indoor fan, so that under the same heating capacity, the temperature of the air entering the indoor space through the indoor unit can be increased, so as to ensure that the air conditioner can continue heating.

Further, the opening degree of the throttle device can be adjusted according to the comparison result of the current exhaust temperature and the target exhaust temperature. First, the current exhaust temperature and target exhaust temperature must be obtained, and the current exhaust temperature and target exhaust temperature must be calculated. According to the difference between the two, the opening degree of the throttling device is specifically adjusted according to the difference between the two. The value of the current exhaust temperature is related to the outdoor environmental conditions of the air conditioner, and can reflect the actual situation of the outdoor environmental conditions of the air conditioner, so that the air conditioner can be better heated while not frosting.

Obviously, when Tc≥Tct-1, in addition to adjusting the operating frequency of the compressor and the rotation speed of the outdoor fan, you can also selectively adjust the opening of the throttling device, the rotation speed of the indoor fan, and the operation of the auxiliary heating device. The status is adapted to the adjustment of the operating frequency of the aforementioned compressor and the rotation speed of the outdoor fan; when Tc<Tct-1, the rotation speed of the outdoor fan is increased while adjusting the section according to the comparison result of the current exhaust temperature and the target exhaust temperature. In addition to the opening of the flow device, you can also selectively adjust the operating frequency of the compressor, the speed of the indoor fan, and the operating status of the auxiliary heating device, such as adjusting the opening of the throttling device first, and then adjusting the operating frequency of the compressor. Then adaptively adjust the speed of the indoor fan and the operating state of the auxiliary heating device according to the indoor environment temperature, so as to realize the stable and continuous heating operation of the air conditioner without frosting. Obviously, the rotation speed of the indoor fan, the opening degree of the throttling device, and the operating state of the auxiliary heating device can be adjusted at the same time, or one or two of the three can be adjusted.

It should be noted that 1 in Ts-1, Ts+1, Tct-1, and Tct+1 of the present invention is the control hysteresis temperature. Obviously, the control hysteresis temperature can also be other values, such as 0.5, which can be based on The control accuracy needs to be adjusted.

Further, the dew point temperature Tdp under outdoor environmental conditions can be calculated according to the formula Tdp=(C ₁ φ ² +C ₂ φ+C ₃ )×Tao-(C ₄ φ ² +C ₅ φ+C _{6 ), and then according to} The dew point temperature Tdp is used to determine the target outer coil temperature Tct. If the dew point temperature Tdp is different, the calculation formula for determining the target outer coil temperature Tct will be different. For example, if the dew point temperature Tdp is greater than the first preset value t ₁ , then Tct=A ₁ *Tdp. For another example, if the dew point temperature Tdp is less than the first preset value t ₁ , then Tct=Tdp+t ₂ . In this way, a more suitable target outer coil temperature can be determined according to the outdoor environmental conditions, and the operating parameters of the air conditioner can be adjusted according to the comparison between the target outer coil temperature and the actual outer coil temperature, so as to control the actual outdoor coil temperature Close to the target outer coil temperature can better keep the air conditioner from heating while not forming frost.

Another aspect of the present invention provides an air conditioner, the air conditioner includes a controller, and the controller is configured to execute the control method of the air conditioner according to any one of the foregoing solutions.

It should be noted that the air conditioner has all the technical effects of the aforementioned control method of the air conditioner, which will not be repeated here.

Description of the drawings

Hereinafter, the control method of the air conditioner of the present invention will be described with reference to the drawings. In the attached picture:

Fig. 1 is a structural schematic diagram 1 of a control method of an air conditioner according to an embodiment of the present invention;

Fig. 2 is a second structural diagram of a control method of an air conditioner according to an embodiment of the present invention;

Fig. 3 is a third structural diagram of a control method of an air conditioner according to an embodiment of the present invention;

4 is a structural schematic diagram 4 of a control method of an air conditioner according to an embodiment of the present invention;

Fig. 5 is a fifth structural diagram of a control method of an air conditioner according to an embodiment of the present invention.

Detailed ways

The preferred embodiments of the present invention will be described below with reference to the drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles 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 term of the indicated direction or positional relationship is based on the direction or positional relationship shown in the drawings, which is only for ease of description, and does not indicate or imply that the device or element must have a specific orientation, be configured and operated in a specific orientation Therefore, it cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance. Moreover, the terms "include", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, or device including a series of elements includes not only those elements, but also other elements that are not explicitly listed. Elements.

The air conditioner includes an indoor unit and an outdoor unit. Through the circulation of the refrigerant between the indoor unit and the outdoor unit, the phase change process of the refrigerant absorbs or releases heat to achieve the purpose of adjusting the indoor ambient temperature. In heating conditions, the condenser of the outdoor unit absorbs the heat in the air, and then transfers this part of the heat to the indoor unit through the refrigerant. The refrigerant exchanges heat with the indoor air to achieve the purpose of improving heating. Generally, the condenser of the outdoor unit includes an upper coil and a lower coil. In the present invention, the temperature of the lower coil in the upper and lower coils is taken as the actual outer coil temperature of the present invention, so that It can better ensure that the outer coil does not form frost.

In the present invention, the heating condition can be a custom heating mode or an intelligent heating mode. The user can set the set temperature through the remote control or other control terminals, or it can be controlled by the controller in the intelligent heating mode. A set temperature, that is, the set temperature is a temperature value that the user hopes to reach. Obviously, the set temperature can be a constant or a variable, and the set temperature may be different for different users and occasions. During the operation of the air conditioner, the indoor environment temperature will change. The operating parameters of the air conditioner can be adjusted in real time according to the difference between the indoor environment temperature and the set temperature, so as to adjust the indoor environment temperature to the required system for the set temperature. Heat, which can better meet the heating needs of users.

In the present invention, the outdoor unit includes a compressor, an outdoor fan and a throttling device, and the indoor unit includes an indoor fan and an auxiliary heating device. The operating frequency of the compressor, the rotation speed of the outdoor fan, and the indoor unit can be selectively adjusted according to the needs of users. One or more operating parameters of the rotation speed of the fan, the opening of the auxiliary heating device and the throttle device, so that the air conditioner does not form frost while the air conditioner continues to heat.

For ease of presentation, the following takes the operating mode of the air conditioner as a custom heating mode as an example to illustrate possible implementations of the present invention.

Fig. 1 is a structural schematic diagram 1 of a control method of an air conditioner according to an embodiment of the present invention. As shown in Fig. 1, the control method of an air conditioner includes:

Step S100: the air conditioner starts to run, and the heating mode is selected;

Step S200: Obtain indoor ambient temperature Tai, outdoor ambient temperature Tao, outer coil temperature Tc, and outdoor air relative humidity φ;

Among them, the indoor ambient temperature Tai, outdoor ambient temperature Tao, outer coil temperature Tc, and outdoor air relative humidity φ can be detected by the indoor ambient temperature sensor, outdoor ambient temperature sensor, outer coil temperature sensor, and outdoor humidity sensor configured by the air conditioner, respectively. Obviously, it can also be obtained by other means.

Step S300: Determine the dew point temperature Tdp under outdoor environmental conditions according to the outdoor environmental temperature Tao and the outdoor air relative humidity φ;

Step S400: Determine the target outer coil temperature Tct according to the outdoor ambient temperature Tao and the dew point temperature Tdp under outdoor ambient conditions;

The target outer coil temperature Tct refers to the temperature that the outer coil is expected to reach. In order to ensure that the air conditioner does not form frost during operation, it is necessary to control the outer coil temperature Tc of the air conditioner close to the target outer coil temperature Tct while heating. The difference can be determined according to different outdoor ambient temperature and outdoor air relative humidity. The target outer coil temperature can ensure the normal heating operation of the air conditioner without frost.

Step S500: Compare the outer coil temperature Tc with the target outer coil temperature Tct, and adjust the operating parameters of the air conditioner according to the comparison result and the indoor ambient temperature Tai;

In this embodiment, according to the comparison result of the outer coil temperature Tc and the target outer coil temperature Tct, combined with the specific value of the indoor ambient temperature Tai, for example, the operation of the air conditioner is adjusted according to the size of the indoor ambient temperature Tai and the set temperature Parameters, make the actual temperature of the outer coil close to the target outer coil temperature while the air conditioner is heating, because the calculated dew point temperature under different outdoor environmental conditions is different. According to different dew point temperatures, two different target outer coil temperatures can be used. The coil temperature algorithm determines the target outer coil temperature, and the target outer coil temperature is greater than the dew point temperature or the freezing point temperature. This ensures that the water vapor in the outdoor air does not condense into water or only condense into water on the surface of the condenser. Frost will form, so frosting will not occur. Through the above setting method, the basis for adjusting the operating parameters of the air conditioner is to compare the indoor ambient temperature and the set temperature, the outer coil temperature and the target outer coil temperature at the same time, so as to ensure that the air conditioner does not heat up while heating. Frost.

Among them, the operating parameters of the air conditioner include one or more of the operating frequency of the compressor, the rotational speed of the outdoor fan, the rotational speed of the indoor fan, the operating state of the auxiliary heating device, and the opening of the electronic expansion valve. Adjusting the operating frequency of the compressor is an operating parameter. It can also be adjusting the operating frequency of the compressor and the speed of the outdoor fan, or two operating parameters such as the speed of the outdoor fan and the speed of the indoor fan. It can also be adjusting the compressor at the same time. There are five operating parameters: operating frequency, outdoor fan speed, indoor fan speed, operating status of auxiliary heating device, and opening degree of throttling device. Those skilled in the art can flexibly select the operating parameters that need to be adjusted according to specific application scenarios. Type, as long as it can realize that the air conditioner does not form frost while heating.

It is understandable that the operating parameters of the air conditioner can also be other types of operating parameters, such as the operating frequency of the motor, etc. Those skilled in the art can flexibly select the types of operating parameters that need to be adjusted according to specific application scenarios, so as to adapt to more specific Application occasions.

The operating frequency of the compressor usually has the maximum and minimum allowable frequencies. If the command is to increase the operating frequency of the compressor, the operating frequency of the compressor will gradually increase, and the maximum limit is the maximum frequency. If the command is to reduce the compressor’s operating frequency, The operating frequency will gradually reduce the operating frequency of the compressor, and the lowest limit is the minimum frequency.

The speed of the outdoor fan and indoor fan can be linearly changed, including the highest speed and the lowest speed. The speed of the outdoor fan and the indoor fan can achieve any speed from the highest speed to the lowest speed. The speed of the outdoor fan and indoor fan can be changed from the highest speed to the lowest speed. The adjustment of the gradual decrease of the high-to-low rotational speed can also realize the adjustment of the gradual increase of the rotational speed from low to high. The speed of the outdoor fan and the indoor fan can also be divided by gears, such as high gear, middle gear, low gear three gears or other possible multiple gears. The appropriate gear can be selected according to specific instructions. Take the outdoor fan as an example. The speed of the outdoor fan runs in the middle gear. The instruction is to reduce the speed of the outdoor fan. Then, change the speed of the outdoor fan to low gear.

The operating state of the auxiliary heating device includes two states: on and off. It can include only these two states, that is, the auxiliary heating device can only operate at one frequency when the auxiliary heating device is on, that is to say, the auxiliary heating device output per unit time The heat flux is not adjustable. You can adjust its actual output heat by adjusting its continuous on time; it can also adjust its output heat by adjusting its operating percentage through multiple sets of electric heating, and its output percentage can be from large to small Decrease gradually, or gradually increase from small to large, or divide the frequency into multiple gears, such as three gears including high gear, middle gear, low gear, or other possible multiple gears, according to specific instructions Choose the right gear.

The opening degree of the electronic expansion valve can usually be adjusted between fully open and fully closed. The adjustment method of the opening degree of the electronic expansion valve can be a fixed range, multiple adjustments, such as 10s adjustment once or 30s adjustment in sequence, etc., or it can be Different amplitudes can be adjusted as needed, as long as the opening degree of the electronic expansion valve can be realized. For example, if the instruction is to increase the opening degree of the electronic expansion valve, the electronic expansion valve is controlled to gradually increase from the current opening degree until the control requirement is reached. In order to ensure the stable operation of the air conditioner, the opening degree of the electronic expansion valve is usually gradually increased or gradually decreased.

Step S600: Exit the heating mode.

Fig. 2 is a second structural diagram of a control method of an air conditioner according to an embodiment of the present invention. As shown in Fig. 2, the control method of an air conditioner includes:

Step S201: the air conditioner starts to run, and the heating mode is selected;

Step S202: Obtain indoor ambient temperature Tai, outdoor ambient temperature Tao, outer coil temperature Tc, and outdoor air relative humidity φ;

Step S203: Determine the dew point temperature Tdp under outdoor environmental conditions according to the outdoor environmental temperature Tao and the outdoor air relative humidity φ;

In this embodiment, the target dew point temperature Tdp under outdoor environmental conditions is calculated by the outdoor environmental temperature Tao and the outdoor air relative humidity φ, which is specifically calculated by the following formula (1):

Tdp=(C ₁ φ ² +C ₂ φ+C ₃ )×Tao-(C ₄ φ ² +C ₅ φ+C ₆ ) (1)

Among them, C ₁ , C ₂ , C ₃ , C ₄ , C ₅ and C ₆ are coefficients, Tao is outdoor ambient temperature, φ is the relative humidity of outdoor air under outdoor environmental conditions, and Tdp is the dew point temperature under outdoor environmental conditions. Obviously, C ₁ , C ₂ , C ₃ , C ₄ , C ₅ and C ₆ can be constants or variables. After repeated experiments and calculations, the inventors have obtained the specific values of the above coefficients: C ₁ =- 0.1, C ₂ =0.32, C ₃ =0.784, C ₄ =15, C ₅ =-40.59, C ₆ =25.761.

In this way, through the above formula, the target dew point temperature Tdp under outdoor environmental conditions can be calculated based on the easily available outdoor ambient temperature Tao and the outdoor air relative humidity φ corresponding to the outdoor ambient temperature Tao, which is simple to calculate and not easy to make mistakes.

Step S204: Compare the dew point temperature Tdp under outdoor environmental conditions with the first preset value t ₁ : If the dew point temperature Tdp under outdoor environmental conditions is greater than or equal to the first preset value t ₁ , then go to step S205; if under outdoor environmental conditions If the dew point temperature Tdp is less than the first preset value t ₁ , then step S206 is executed;

In this embodiment, t ₁ can be a constant or a variable, such as t ₁ =2.

Step S205: Use the following formula (2) to determine the target outer coil temperature Tc:

Tct＝A ₁ *Tdp (2)

Step S206: Use the following formula (3) to determine the target outer coil temperature Tc:

Tct=Tdp+t ₂ (3)

Among them, in the above formulas (1) and (2), both A ₁ and t ₂ are coefficients and are positive numbers. A ₁ and t ₂ can be constants or variables. After repeated experiments, demonstrations, and calculations, the inventors have found that the specific values of the above coefficients are: A ₁ =0.55, t ₂ =2.

Through the above setting method, the dew point temperature Tdp under different outdoor environmental conditions with different outdoor ambient temperature and outdoor air relative humidity φ, and the target dew point temperature Tdp under different outdoor environmental conditions correspond to different target outer coil temperatures Tct, that is, different The outdoor environmental conditions correspond to different target outer coil temperature Tct. For example, when Tdp≥2, the target outer coil temperature is determined by the formula Tct=0.55*Tdp, so that the calculated target outer coil temperature is less than the dew point temperature and greater than the freezing point temperature, so that the actual temperature of the outer coil is close to the target outside At the temperature of the coil, the water vapor in the outdoor air will condense on the surface of the outer coil without frost; another example is when Tdp<2, the target outer coil temperature is determined _{by the formula Tct=Tdp+t 2, so} The calculated target outer coil temperature is greater than the dew point temperature, so that when the actual temperature of the outer coil is close to the target outer coil temperature, the water vapor in the outdoor air will not condense into water on the surface of the outer coil, which can better ensure Does not frost.

Step S207: Compare the outer coil temperature Tc with the target outer coil temperature Tct, and adjust the operating parameters of the air conditioner according to the comparison result and the indoor ambient temperature Tai;

Step S208: Exit the heating mode.

Fig. 3 is a third structural diagram of a control method of an air conditioner according to an embodiment of the present invention. As shown in Fig. 3, the control method of an air conditioner includes:

Step S301: the air conditioner starts to run, and the heating mode is selected;

Step S302: Obtain indoor ambient temperature Tai, set temperature Ts, outdoor ambient temperature Tao, and outdoor air relative humidity φ;

Step S303: Determine the dew point temperature Tdp under outdoor environmental conditions according to the outdoor environmental temperature Tao and the outdoor air relative humidity φ;

Step S304: Determine the target outer coil temperature Tct according to the outdoor ambient temperature Tao and the dew point temperature Tdp under outdoor ambient conditions;

Step S305: Compare the indoor ambient temperature Tai with the set temperature Ts, if Tai<Ts-1, go to step S306;

Step S306: Compare the outer coil temperature Tc with the target outer coil temperature Tct: if Tc>Tct+1, go to step S307; if Tct-1≤Tc≤Tct+1, go to step S308; if Tc<Tct- 1. Step S309 is executed;

Step S307: increasing the operating frequency of the compressor and keeping the rotation speed of the outdoor fan unchanged;

Step S308: Increase the operating frequency of the compressor and the rotational speed of the outdoor fan;

Step S309: increasing the rotation speed of the outdoor fan;

Step S310: Turn on the auxiliary heating device;

In this embodiment, the auxiliary heating device can automatically control all to be turned on or turn on by a percentage according to the temperature difference between the indoor ambient temperature and the set temperature, based on meeting the heating demand of the air conditioner.

Step S311: Decrease the rotation speed of the indoor fan.

In this embodiment, among the six groups of steps, step 307 and step S310, step 307 and step S311, step 308 and step S310, step 308 and step S311, step 309 and step S310, step 309 and step S311, two steps in each group These steps can be executed at the same time, or one can be executed first and then the other. Those skilled in the art can flexibly choose the execution order of the two steps according to specific application scenarios, as long as the air conditioner can continue heating without frosting. That's it.

In this embodiment, generally, when the system is fully matched, it can meet the use requirements of the design working condition. Considering that the room load demand is far greater than the air conditioning capacity range, after the above steps 307, 308 or S309 are executed, if the indoor ambient temperature Tai has not reached the set temperature Ts, and/or the external coil temperature Tc has not reached the target external coil For the temperature Tct, step S310 or step S311 or step S310 and step S311 can be selectively performed. Those skilled in the art can flexibly choose the steps to be performed according to specific application scenarios, as long as the air conditioner can continue to heat up while not shutting down. Just frost. Obviously, it is also possible to perform only to step S307, S308 or S309, as long as it is ensured that the air conditioner does not form frost while heating continuously. For example, when Tai<Ts-1 and Tc>Tct+1, only go to step S307, another example, when Tai<Ts-1 and Tct-1≤Tc≤Tct+1, only go to step S308; another example, When Tai<Ts-1 and Tc<Tct-1, only go to step S309.

In this embodiment, when the indoor ambient temperature Tai is less than the set temperature Ts-1, the temperature of the indoor space is low at this time, and the air conditioner needs to heat in order to increase the temperature of the indoor space. At the same time, compare the outer coil temperature Tc with the target outer coil temperature Tct, and adjust the operating frequency of the compressor and the speed of the outdoor fan according to the size of the two and the heating demand, so as to achieve the simultaneous heating of the air conditioner Does not frost. For example, when the outer coil temperature Tc is greater than the target outer coil temperature Tct+1, the actual temperature of the outer coil is higher. At this time, the operating frequency of the compressor is increased and the speed of the outdoor fan remains unchanged. Increase the refrigerant circulation, while the outdoor air volume remains unchanged, that is, the heating capacity that can be provided to the indoor unit does not decrease, thereby ensuring the user's heating demand. However, due to the increase in the refrigerant volume and the decrease in the air volume of the outdoor fan It is small, so that the air volume that can exchange heat with a unit amount of refrigerant is reduced, which will also cause the temperature of the refrigerant to decrease, thereby reducing the temperature of the outer coil, so that the outer plate can be reduced without reducing the speed of the outdoor fan The purpose of the temperature of the tube. For another example, when the outer coil temperature Tc is close to the target outer coil temperature Tct, the operating frequency of the compressor and the rotation speed of the outdoor fan increase. For another example, when the outer coil temperature Tc is less than the target outer coil temperature Tct-1, only the rotation speed of the outdoor fan can be increased, or the opening of the electronic expansion valve can be appropriately adjusted while increasing the rotation speed of the outdoor fan. When the rotation speed of the outdoor fan rises to the maximum rotation speed, Tc is still less than Tct-1, which can reduce the operating frequency of the compressor, reduce the circulation of refrigerant, and further increase the temperature of the refrigerant, thereby ensuring that the air conditioner operates without frost.

Fig. 4 is a structural schematic diagram 4 of a control method of an air conditioner according to an embodiment of the present invention. As shown in Fig. 4, the control method of an air conditioner includes:

Step S401: the air conditioner starts to run, and the heating mode is selected;

Step S402: Obtain indoor ambient temperature Tai, set temperature Ts, outdoor ambient temperature Tao, and outdoor air relative humidity φ;

Step S403: Determine the dew point temperature Tdp under outdoor environmental conditions according to the outdoor environmental temperature Tao and the outdoor air relative humidity φ;

Step S404: Determine the target outer coil temperature Tct according to the outdoor ambient temperature Tao and the dew point temperature Tdp under outdoor ambient conditions;

Step S405: Compare the indoor ambient temperature Tai with the set temperature Ts, if Ts-1≤Tai≤Ts+1, then execute step S406;

Step S406: Compare the outer coil temperature Tc with the target outer coil temperature Tct: if Tc>Tct+1, go to step S407; if Tct-1≤Tc≤Tct+1, go to step S408; if Tc<Tct- 1. Step S409 is executed;

Step S407: Keep the operating frequency of the compressor unchanged, and reduce the speed of the outdoor fan;

Step S408: Keep the operating frequency of the compressor and the rotation speed of the outdoor fan unchanged;

Step S409: increasing the speed of the outdoor fan;

Step S410: Turn on the auxiliary heating device;

In this embodiment, the auxiliary heating device can automatically control all to be turned on or turn on by a percentage according to the temperature difference between the indoor ambient temperature and the set temperature, so as to meet the heating demand of the air conditioner.

Step S411: Decrease the speed of the indoor fan.

In this embodiment, among the six sets of steps, step 407 and step S410, step 407 and step S411, step 408 and step S410, step 408 and step S411, step 409 and step S410, step 409 and step S411, two of each set of steps These steps can be executed at the same time, or one can be executed first and then the other. Those skilled in the art can flexibly choose the execution order of the two steps according to specific application scenarios, as long as the air conditioner can continue heating without frosting. That's it.

In this embodiment, generally, when the system is fully matched, it can meet the use requirements of the design working condition. Considering that the room load demand is far greater than the air conditioning capacity range, after the above steps 407, 408 or S409 are executed, if the indoor ambient temperature Tai has not reached the set temperature Ts, and/or the external coil temperature Tc has not reached the target external coil For temperature Tct, step S410 or step S411 or step S410 and step S411 can be selectively performed. Those skilled in the art can flexibly select the steps to be performed according to specific application scenarios, as long as the air conditioner can continue to heat up while not shutting down. Just frost. Obviously, it is also possible to perform only to steps 407, 408 or S409, as long as it is ensured that the air conditioner does not form frost while continuing to heat. For example, when Tai<Ts-1 and Tc>Tct+1, only go to step S407, another example, when Tai<Ts-1 and Tct-1≤Tc≤Tct+1, only go to step S408; another example, When Tai<Ts-1 and Tc<Tct-1, only go to step S409.

In this embodiment, when the indoor ambient temperature Tai is close to the set temperature Ts, the temperature of the indoor space is relatively moderate at this time, and there is no need to specifically adjust the indoor ambient temperature. It is only necessary to ensure that the outer coil is not heated during the heating process of the air conditioner. frost. While adjusting the operating frequency of the compressor and the speed of the outdoor fan according to the outer coil temperature Tc and the target outer coil temperature Tct, it is also necessary to pay attention to the change of the indoor environment temperature to ensure that it is continuously in a moderate range to achieve air conditioning The device does not frost while heating. For example, when the outer coil temperature Tc is greater than the target outer coil temperature Tct+1, and when the outer coil temperature Tc is greater than the target outer coil temperature Tct+1, the actual temperature of the outer coil is too high, which causes the compressor to operate The frequency remains the same, the speed of the outdoor fan decreases, and the amount of outdoor air that exchanges heat with the refrigerant decreases, resulting in a decrease in the amount of heat that the refrigerant flowing through the outer coil can absorb, and the temperature of the refrigerant decreases, which in turn reduces the amount of heat in the outer coil. By reducing the temperature of the outer coil, the heat exchange temperature difference between the outdoor air and the refrigerant can be increased, and the heat exchange between the outdoor air and the refrigerant is positively related to the product of the outdoor air volume and the heat exchange temperature difference. It is also possible to ensure the heating capacity while ensuring no frost, so that the indoor ambient temperature continues to be in a relatively moderate range. For another example, when the outer coil temperature Tc is close to the target outer coil temperature Tct, the original operating state can be maintained. For another example, when the outer coil temperature Tc is less than the target outer coil temperature Tct-1, only the rotation speed of the outdoor fan can be increased, or the opening of the electronic expansion valve can be appropriately adjusted while increasing the rotation speed of the outdoor fan. When the rotation speed of the outdoor fan rises to the maximum rotation speed, Tc is still less than Tct-1, which can reduce the operating frequency of the compressor, reduce the circulation of the refrigerant, and further increase the temperature of the refrigerant, thereby ensuring the heating operation of the air conditioner without frosting.

In Figures 3 and 4, when Tc is greater than or equal to Tct-1, the air conditioner can selectively adjust the operating status of the auxiliary heating device and the indoor fan after adjusting the operating frequency of the compressor and the speed of the outdoor fan as described above. All or part of the speed and the opening degree of the throttling device are used to make the outer coil temperature close to the target outer coil temperature and the indoor ambient temperature to increase to the set temperature; when Tc is less than Tct-1, the outdoor fan can be After the speed rises, the opening degree of the electronic expansion valve is adjusted first, and then the operating frequency of the compressor is adjusted, and then the speed of the indoor fan and the operating state of the auxiliary heating device are adaptively adjusted according to the indoor ambient temperature. In this way, the indoor ambient temperature Tai can be close to the set temperature Ts, and the outer coil temperature Tc can be close to the target outer coil temperature Tct at the same time, so as to achieve the purpose of heating without frosting.

It should be noted that the speed of the indoor fan usually runs normally according to the set speed. If the temperature sensor of the inner coil of the air conditioner detects that the temperature of the inner coil is low, so that when the indoor environment temperature is reduced, the indoor fan can be appropriately reduced. Rotation speed, that is, the above step S311 or S411 is executed to reduce the air volume of the indoor air that exchanges heat with the inner coil, so as to increase the temperature of the inner coil, so that the air conditioner can continue to heat.

In this embodiment, in order to realize the heating of the air conditioner without frosting, in addition to adjusting the operating frequency of the compressor, the speed of the outdoor fan, the speed of the indoor fan, and the operating state of the auxiliary heating device, the electronic expansion can also be adjusted. The opening of the valve to ensure the stable operation of the air conditioner.

At present, the opening degree of the electronic expansion valve is usually adjusted by using the target suction superheat look-up table or the target exhaust superheat section look-up table method. However, the disadvantage of the target suction superheat look-up table method is the suction temperature. The temperature of the coil is not much different, the superheat accuracy is not enough, and the problem of improper valve adjustment is prone to occur. Moreover, most air conditioners usually use capillary shunting, which is difficult to ensure good shunt consistency, which leads to the calculation of target inhalation. It is also difficult to ensure a good consistency of the inner coil temperature of the heat, and the deviation between the coil temperatures is large, which leads to low accuracy of the superheat check-up valve. Especially when the piping is long and the drop is large, due to the system pressure loss, the suction superheat is distorted, and the valve is adjusted according to the target suction superheat, which cannot meet the requirements of optimal performance. When the electronic expansion valve is controlled by the target exhaust superheat segmented look-up table, due to the limited number of segments, it is usually unable to adapt to a large outdoor ambient temperature range.

In this embodiment, the opening of the electronic expansion valve is adjusted by the difference between the current exhaust temperature Td and the target exhaust temperature Tdt. The current exhaust temperature Td can be detected by the exhaust temperature sensor of the air conditioner. Depending on the operating conditions of the air conditioner, the current exhaust temperature will also be different; the target exhaust temperature should be understood as the expected temperature that the compressor exhaust temperature should reach under the current operating conditions. The target exhaust temperature can be It can be directly set based on experience, and it can also be calculated based on parameters such as the condenser temperature of the compressor and the outdoor ambient temperature. Those skilled in the art can choose the method of determining the target exhaust temperature according to the actual situation, which will not be repeated here.

By adjusting the operating frequency of the aforementioned compressor, the rotational speed of the outdoor fan, the auxiliary heating device and/or the rotational speed of the indoor fan, the operating conditions of the air conditioner will inevitably be changed, and the current exhaust temperature Td will also change accordingly, namely The difference between the current exhaust temperature Td and the target exhaust temperature Tdt is related to the actual operating conditions of the air conditioner, which can reflect the actual operating conditions of the air conditioner, so that under different operating conditions, it can be The difference is used to adjust the electronic expansion valve, which can better prevent frost while the air conditioner continues to heat.

Hereinafter, a possible implementation manner of adjusting the opening degree of the electronic expansion valve of the present invention will be described with reference to the accompanying drawings.

Fig. 5 is a structural schematic diagram 5 of a control method of an air conditioner according to an embodiment of the present invention. As shown in Fig. 5, the control method of an air conditioner includes:

Step S501: the air conditioner starts to run, and the heating mode is selected;

Step S502: Obtain the current exhaust temperature Td;

Step S503: Calculate the difference between the current exhaust temperature Td and the target exhaust temperature Tdt, and adjust the opening of the electronic expansion valve according to the difference between the current exhaust temperature Td and the target exhaust temperature Tdt: if Td -Tdt<-1°C, go to step S504; if not, go to step S505;

Step S504: Decrease the opening degree of the electronic expansion valve;

The opening degree of the electronic expansion valve directly affects the flow rate of the refrigerant flowing to the indoor unit. When Td-Tdt<-1℃, it means that the current exhaust temperature Td is too low, and the current exhaust temperature Td needs to be increased. By reducing the opening of the electronic expansion valve, the amount of indoor air for heat exchange between the room and the refrigerant remains unchanged. In this way, the temperature of the inner coil can be increased, and the temperature of the refrigerant returning to the compressor will increase, thereby increasing the current exhaust temperature Td. At the same time, the increase in the temperature of the inner coil can also increase the temperature of the indoor air that exchanges heat with the inner coil, so that even if the amount of refrigerant flowing to the indoor unit is reduced, the heating capacity of the air conditioner can be ensured.

Step S505: If Td-Tdt>1°C, execute step S506; if not, execute step S507;

Step S506: Increase the opening degree of the electronic expansion valve;

When Td-Tdt>1℃, it means that the current exhaust temperature Td is too high, and it is necessary to reduce the current exhaust temperature Td, increase the opening of the electronic expansion valve, and the amount of indoor air for heat exchange between the room and the refrigerant remains unchanged. The temperature of the inner coil can be lowered, and the temperature of the refrigerant returning to the compressor will be lowered, so that the current exhaust temperature Td can be appropriately lowered. At the same time, the decrease in the temperature of the inner coil reduces the temperature of the indoor air that exchanges heat with the inner coil. However, the amount of refrigerant flowing to the indoor unit increases, thereby ensuring the heating capacity of the air conditioner.

Step S507: If -1°C≤Td-Tdt≤1°C, go to step S508; if not, go back to step S503;

Step S508: Keep the opening degree of the electronic expansion valve unchanged.

When -1℃≤Td-Tdt≤1℃, it means that the current exhaust temperature Td is in a suitable range and there is no need to change the opening degree of the electronic expansion valve.

The above steps S503 and S307, step S310, step S311, or step S503 and step S308, step S310, step S311, or step S503 and step S309, step S310, step S311, or step S503 and step S407, step S410, step S411, or step S503 and step S408, step S410, step S411, or step S503 and step S409, step S410, step S411, can be executed at the same time, can also be executed one by one in a sequence, or can be executed at the same time. The two and other steps are executed one by one in the order of priority. It is also possible to execute only one or two of the possible steps, as long as it can ensure that the air conditioner is not frosting while heating.

In a specific embodiment, when Tc<Tct-1, the indoor ambient temperature Tai is not considered, and step S503 is performed at the same time when step S309 or step S409 is performed, that is, while increasing the rotation speed of the outdoor fan, according to the current exhaust The difference between the air temperature Td and the target exhaust temperature Tdt is used to adjust the opening of the electronic expansion valve. If the speed of the outdoor fan rises to the maximum speed, the outer coil temperature Tc is still less than the target outer coil temperature Tct-1 , You can reduce the operating frequency of the compressor, reduce the amount of refrigerant circulating, further increase the temperature of the refrigerant, and then increase the temperature of the outer coil to prevent the outer coil from frosting. At this time, if the indoor ambient temperature Tai is low, you can also selectively Adjust the operating status of the auxiliary heating device and/or the rotation speed of the indoor fan to ensure the heating performance of the air conditioner, so that no frost will form during the continuous heating process.

In summary, in the preferred technical solution of the present invention, the target outer coil temperature and the outer coil temperature, as well as the indoor ambient temperature and the set temperature are compared, and based on the comparison result, the controller makes the compressor The operating frequency and the rotation speed of the outdoor fan increase, decrease or remain unchanged, and the opening of the throttle device, the rotation speed of the indoor fan and/or the operating state of the auxiliary heating device are selectively adjusted to ensure continuous heating while the air conditioner No frost; determine the dew point temperature under outdoor environmental conditions by the outdoor ambient temperature and the relative humidity of the outdoor air, and then use different calculation formulas to determine the target outer coil temperature according to the dew point temperature, and take the target outer coil temperature as The target value of the outer coil temperature can better ensure that the outer coil does not form frost; determine the target exhaust temperature according to the compressor's condensation temperature range and the outdoor ambient temperature, compare the current exhaust temperature and target exhaust temperature, and adjust the electronic The opening of the expansion valve. Through the above arrangement, it is possible to realize that the air conditioner does not form frost while heating.

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

Claims (10)

1. A control method of an air conditioner, characterized in that the control method includes:

   Obtain outdoor ambient temperature Tao, indoor ambient temperature Tai, outdoor air relative humidity φ, and outer coil temperature Tc;

   Determine the dew point temperature Tdp under outdoor environmental conditions according to the outdoor environmental temperature Tao and the outdoor air relative humidity φ;

   Determine the target outer coil temperature Tct according to the outdoor environmental temperature Tao and the dew point temperature Tdp under the outdoor environmental conditions;

   Comparing the target outer coil temperature Tct with the outer coil temperature Tc;

   According to the comparison result and the indoor ambient temperature Tai, the operating parameters of the air conditioner are adjusted.
2. The control method according to claim 1, wherein the air conditioner includes an indoor unit and an outdoor unit, the indoor unit includes an indoor fan and an auxiliary heating device, and the outdoor unit includes a compressor, an outdoor fan, and a throttle. Device,

   The operating parameters of the air conditioner include one or more of the operating frequency of the compressor, the rotational speed of the outdoor fan, the rotational speed of the indoor fan, the opening of the throttle device, and the operating state of the auxiliary heating device.
3. The control method according to claim 2, wherein the “compare the target outer coil temperature Tct with the outer coil temperature Tc; adjust the air conditioner according to the comparison result and the indoor ambient temperature Tai "The operating parameters of the device" include:

   When the indoor ambient temperature Tai<the set temperature Ts-1, and:

   When Tc>Tct+1, the operating frequency of the compressor is increased, and the rotation speed of the outdoor fan is kept unchanged, and the opening of the throttling device, the rotation speed of the indoor fan and/ Or the operating state of the auxiliary heating device;

   When Tct-1≤Tc≤Tct+1, the operating frequency of the compressor and the rotation speed of the outdoor fan are increased, and the opening of the throttling device, the rotation speed of the indoor fan and/or The operating state of the auxiliary heating device.
4. The control method according to claim 2, wherein the “compare the target outer coil temperature Tct with the outer coil temperature Tc; adjust the air conditioner according to the comparison result and the indoor ambient temperature Tai "The operating parameters of the device" include:

   When the set temperature Ts-1≤the indoor ambient temperature Tai≤the set temperature Ts+1, and:

   When Tc>Tct+1, the operating frequency of the compressor is kept unchanged, and the rotation speed of the outdoor fan is reduced, and the opening of the throttling device, the rotation speed of the indoor fan and/ Or the operating state of the auxiliary heating device;

   When Tct-1≤Tc≤Tct+1, the operating frequency of the compressor and the rotation speed of the outdoor fan are kept unchanged, and the opening degree of the throttling device, the rotation speed of the indoor fan and /Or the operating state of the auxiliary heating device.
5. The control method according to any one of claims 2-4, wherein the “compare the target outer coil temperature Tct with the outer coil temperature Tc; according to the comparison result and the indoor environment "Temperature Tai adjusts the operating parameters of the air conditioner" includes:

   Turn on the auxiliary heating device and/or reduce the rotational speed of the indoor fan.
6. The control method according to any one of claims 2-4, wherein the “compare the target outer coil temperature Tct with the outer coil temperature Tc; according to the comparison result and the indoor environment "Temperature Tai adjusts the operating parameters of the air conditioner" includes:

   Obtain the current exhaust temperature Td;

   The current exhaust temperature Td and the target exhaust temperature Tdt are compared, and the opening degree of the throttle device is adjusted according to the comparison result.
7. The control method according to any one of claims 2-4, wherein the “compare the target outer coil temperature Tct with the outer coil temperature Tc; according to the comparison result and the indoor environment "Temperature Tai adjusts the operating parameters of the air conditioner" includes:

   When Tc<Tct-1, adjust the operating parameters of the air conditioner as follows:

   Increase the speed of the outdoor fan;

   Selectively adjusting the opening degree of the throttle device according to the comparison result of the current exhaust temperature Td and the target exhaust temperature Tdt; and

   Selectively adjust the operating frequency of the compressor, the rotational speed of the indoor fan, and/or the operating state of the auxiliary heating device.
8. The control method according to claim 1, wherein the "determining the dew point temperature Tdp under outdoor environmental conditions according to the outdoor environmental temperature Tao and the outdoor air relative humidity φ" specifically includes:

   Determine the dew point temperature Tdp under outdoor environmental conditions according to the following formula:

   Tdp=(C ₁ φ ² +C ₂ φ+C ₃ )×Tao-(C ₄ φ ² +C ₅ φ+C ₆ )

   Wherein, C ₁ , C ₂ , C ₃ , C ₄ , C ₅ and C ₆ are coefficients, Tao is the outdoor environmental temperature, φ is the outdoor environmental relative humidity, and Tdp is the dew point temperature under outdoor environmental conditions.
9. The control method according to claim 8, wherein the "determining the target outer coil temperature Tct according to the outdoor ambient temperature Tao and the dew point temperature Tdp under outdoor environmental conditions" specifically includes:

   If the dew point temperature Tdp under outdoor environmental conditions is greater than or equal to the first preset value t ₁ , the target outer coil temperature Tct is determined according to the following formula:

   Tct＝A ₁ *Tdp

   If the dew point temperature Tdp under outdoor environmental conditions is less than the first preset value t ₁ , the target outer coil temperature Tct is determined according to the following formula:

   Tct=Tdp+t ₂

   Among them, A ₁ is a coefficient, and t ₁ and t ₂ are coefficients.
10. An air conditioner, characterized in that the air conditioner includes a controller, and the controller is configured to execute the air conditioner control method according to any one of claims 1 to 9.

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