Air conditioner control method and device and air conditioner

Abstract

The embodiment of the invention provides a control method and device of an air conditioner and the air conditioner. According to the control method, when the air conditioner is in a heating mode, whether the air conditioner is frosted or not during operation under the working condition is judged; the indoor temperature, the set temperature of the air conditioner and the outer pipe temperature of the air conditioner in the running process of the air conditioner are detected, whether the air conditioner needs to be defrosted or not is judged according to the three temperatures, in the defrosting period, the defrosting time is shortened by adjusting the running frequency of a compressor and the opening degree of an electronic expansion valve, and the defrosting efficiency is improved. And indoor temperature reduction caused by too long defrosting time is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to a control method and device of an air conditioner and an air conditioner. Background Art

[0002] In low temperature conditions, when the air conditioner is in heating operation, in order to ensure its normal operation and efficient heating performance, a defrosting operation is required. In the prior art, the air conditioner usually determines whether to enter the defrosting mode based on the outdoor ambient temperature and the outdoor heat exchanger pipe temperature.

[0003] However, in actual use, when users set different wind speeds according to their own needs, the frosting of the air conditioner will be significantly different. Specifically, when the user sets it to medium or low wind speed, the air flow rate through the outdoor heat exchanger is relatively low at this time, which makes the frosting cycle of the air conditioner significantly longer. A long frosting cycle will cause the surface of the outdoor heat exchanger to be thicker when the air conditioner enters the defrost mode. More heat is required to melt the frost, and accordingly, the time required for defrosting will be greatly extended. During the defrosting process, in order to provide the outdoor heat exchanger with the heat required for defrosting, the working mode of the air conditioner will change, usually stopping or reducing the heat supply to the room, causing the indoor temperature to drop, affecting the user's comfort. Summary of the invention

[0004] The embodiments of the present invention provide a control method and device for an air conditioner, and an air conditioner, aiming to solve the problem that the existing air conditioner has a long frosting period when operating at different wind speeds, resulting in a drop in indoor temperature during the defrosting process.

[0005] In a first aspect, an embodiment of the present invention provides a control method for an air conditioner, which is applied to an air conditioner, wherein the air conditioner includes a compressor and an electronic expansion valve, and the control method includes:

[0006] When the air conditioner is in heating mode, determine whether frost will form during operation of the air conditioner;

[0007] If frost will form, then after the first predetermined time of operation, the indoor temperature, the set temperature of the air conditioner and the temperature of the external pipe of the air conditioner are obtained, and it is determined whether the air conditioner needs to enter defrosting mode;

[0008] If defrosting is required, adjust the operating frequency of the compressor and the opening of the electronic expansion valve to speed up defrosting.

[0009] In a second aspect, an embodiment of the present invention provides a control device for an air conditioner, comprising:

[0010] A frost determination unit, used to determine whether frost will form during operation of the air conditioner when the air conditioner is in a heating mode;

[0011] A defrost judgment unit, for obtaining the indoor temperature, the set temperature of the air conditioner and the temperature of the outer pipe of the air conditioner after the first predetermined operation time if frost will form, and judging whether the air conditioner needs to enter defrost mode;

[0012] The adjustment unit is used to adjust the operating frequency of the compressor and the opening of the electronic expansion valve to speed up defrosting if defrosting is required.

[0013] In a third aspect, an embodiment of the present invention provides an air conditioner, comprising a compressor and an electronic expansion valve, and also comprising the control device as described above.

[0014] The embodiment of the present invention provides a control method, device and air conditioner of an air conditioner. The control method determines whether frost will form when the air conditioner is in a heating mode. When frost will form, the indoor temperature, the set temperature of the air conditioner and the external pipe temperature of the air conditioner during the operation of the air conditioner are detected, and whether the air conditioner needs to enter defrosting is determined based on these three temperatures. During defrosting, the defrosting time is shortened by adjusting the operating frequency of the compressor and the opening of the electronic expansion valve to avoid a drop in indoor temperature due to too long defrosting time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0016] Figure 1 A schematic flow chart of a method for controlling an air conditioner provided by an embodiment of the present invention;

[0017] Figure 2 A sub-process diagram of a method for controlling an air conditioner provided by an embodiment of the present invention Figure 1 ;

[0018] Figure 3 A sub-process diagram of a method for controlling an air conditioner provided by an embodiment of the present invention Figure 2 ;

[0019] Figure 4 A sub-process diagram of a method for controlling an air conditioner provided by an embodiment of the present invention Figure 3 ;

[0020] Figure 5 A logic diagram of a control method for an air conditioner provided by an embodiment of the present invention Figure 1 ;

[0021] Figure 6A sub-process diagram of a method for controlling an air conditioner provided by an embodiment of the present invention Figure 4 ;

[0022] Figure 7 A sub-process diagram of a method for controlling an air conditioner provided by an embodiment of the present invention Figure 5 ;

[0023] Figure 8 A logic diagram of a control method for an air conditioner provided by an embodiment of the present invention Figure 2 ;

[0024] Fig. 9 A schematic block diagram of a control device for an air conditioner provided by an embodiment of the present invention;

[0025] Fig.10 A simplified structural diagram of an air conditioner provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0028] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0029] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0030] See also Figure 1 The embodiment of the present invention provides a control method for an air conditioner, which is applied to the air conditioner. The air conditioner includes a compressor and an electronic expansion valve. The control method includes S10-S30:

[0031] S10, when the air conditioner is in heating mode, determining whether frost will form during operation of the air conditioner;

[0032] In this step, when the air conditioner is in a low temperature condition, the heating mode needs to be started, and it is necessary to determine whether the air conditioner will frost during operation, so that measures can be taken in advance to prevent the influence of too thick frost layer on the heat exchange efficiency of the outdoor heat exchanger. If the frosting state is not judged in time, when the frost layer accumulates on the surface of the outdoor heat exchanger, it will increase the thermal resistance, hinder the heat transfer from the outdoor air to the refrigerant, and cause the heat exchange efficiency to decrease, thereby affecting the heating capacity of the air conditioner. In addition, when the frosting is severe, the air conditioning system may frequently enter the defrosting mode, and during the defrosting process, the air conditioner will usually suspend or reduce the heating function, and the indoor temperature will drop due to the defrosting operation of the air conditioner. Especially in cold weather, this temperature fluctuation will bring an uncomfortable experience to the user. Therefore, it is necessary to judge and control the frosting in advance to reduce the switching of the air conditioning state, ensure the continuity of heating, and keep the indoor temperature within a relatively stable and comfortable range.

[0033] In the specific implementation, the outdoor temperature T is detected and obtained in real time. 室外 , the risk of frost can be detected in advance, such as Figure 2 As shown, S10 includes:

[0034] S11. Get outdoor temperature T 室外 , and the outdoor temperature T 室外 With the first predetermined temperature T 预定1 For comparison:

[0035] S12, if the outdoor temperature T 室外 is lower than the first predetermined temperature T 预定1 , it is confirmed that the air conditioner will frost during operation.

[0036] The first predetermined temperature can be set to 5°C. When the outdoor temperature is lower than the predetermined temperature, it indicates that the outdoor environment is in a low temperature state and the possibility of frosting of the air conditioner increases. When it is confirmed that the air conditioner will frost during operation, measures can be taken in advance (such as defrosting in advance or adjusting the operating parameters of the air conditioner) to reduce the impact of frosting on the heating performance of the air conditioner, make the indoor temperature more stable, and improve the user's comfort.

[0037] In a specific embodiment, a threshold value of the drop rate of the outdoor heat exchanger tube temperature can also be set, such as 0.5°C / min. The air conditioner calculates the change rate of the outdoor heat exchanger tube temperature within a period of time (such as the last 5 minutes). If the tube temperature drop rate exceeds the threshold, it indicates that the tube temperature drops too fast and there may be a tendency to frost. In addition, an absolute temperature threshold value of the outdoor heat exchanger tube temperature can also be set, such as -2°C. If the outdoor heat exchanger tube temperature is lower than the absolute temperature threshold value, it also indicates that the air conditioner will frost during operation.

[0038] S20, if frost will form, then run for the first predetermined time t 预定1 Then, get the indoor temperature T 室内 、The set temperature of the air conditioner is T 设 And the external pipe temperature T of the air conditioner 外管 , and judge whether the air conditioner needs to enter defrosting;

[0039] In this step, the difference between the indoor temperature and the set temperature of the air conditioner can reflect the current heating effect of the air conditioner, and the external pipe temperature of the air conditioner can reflect the frosting condition of the outdoor heat exchanger. Through these three temperatures, the time for defrosting can be determined more accurately. For example, if the indoor temperature is significantly different from the set temperature, it means that the current heating effect of the air conditioner has not yet met the user's needs. At this time, even if the external pipe temperature indicates that there is a risk of frosting, the defrosting operation can be appropriately delayed to give priority to meeting the indoor heating needs; conversely, if the indoor temperature is close to the set temperature and the external pipe temperature shows that the frosting is severe, defrosting can be performed in advance to prevent the frosting from further deteriorating and affecting the subsequent heating effect.

[0040] In addition, the present embodiment makes a judgment after a certain operating time (i.e., the first predetermined time) is met, which allows the air conditioner to accumulate sufficient operating data to a certain extent, more accurately reflect the current operating status, and avoid making erroneous defrost judgments due to short-term temperature fluctuations or data instability at the beginning of operation, thereby ensuring the accuracy and reliability of defrost decisions.

[0041] In one embodiment, if Figure 3 As shown, S20 includes:

[0042] S21, obtaining the operating time of the air conditioner;

[0043] S22: If the running time of the air conditioner reaches the first predetermined time, obtain the indoor temperature T 室内 and the set temperature T of the air conditioner 设 , and calculate the indoor temperature T 室内 and the set temperature T of the air conditioner 设 The first temperature difference T 差值1 ;

[0044] S23, if the first temperature difference T差值1 Less than or equal to the first preset difference T 预设差值1 , it is confirmed that the air conditioner needs to enter defrosting mode;

[0045] S24, if the first temperature difference T 差值1 Greater than the first preset difference T 预设差值1 , then get the external pipe temperature T of the air conditioner 外管 And as the first outer tube temperature T 外管1 , and the first outer tube temperature T 外管1 and the second predetermined temperature T 预定2 Make comparisons;

[0046] S25, if the first outer tube temperature T 外管1 is less than or equal to the second predetermined temperature T 预定2 , it confirms that the air conditioner needs to enter defrost mode.

[0047] In S21, a timer needs to be set to start timing from when the air conditioner starts running in the heating mode. The timer can be a hardware timer or a software timer. The timer updates the running time at a certain time interval (for example, 1 second) to ensure accurate recording of the running time.

[0048] In S22, the first predetermined time can be set to 40 minutes. When the count value of the timer reaches 40 minutes, the indoor temperature and the set temperature of the air conditioner are obtained, and the first temperature difference between the indoor temperature and the set temperature of the air conditioner is calculated, that is, the first temperature difference = indoor temperature - set temperature of the air conditioner.

[0049] In S23, when the first temperature difference is less than or equal to the first preset difference, it indicates that the current indoor temperature is close to the temperature set by the user, and the air conditioner enters defrosting at this time, which does not affect the user's comfort, wherein the first preset difference may be 2°C. After that, the air conditioner enters defrosting once after each operation time of △m (△m may be 30 minutes, and this recommended value can avoid frequent defrosting of the air conditioner in a short period of time, and can also prevent the air conditioner from running for a long time and causing thick frost to cause a longer defrosting time), so as to ensure the indoor temperature comfort while allowing the air conditioner to enter defrosting quickly, and avoid thick frost due to long operation time, which causes a longer defrosting time and thus affects the indoor temperature.

[0050] In S24, when the first temperature difference is greater than the first preset difference, it indicates that the indoor temperature is not high at this time and is in the rising stage. It is necessary to consider the speed of the indoor temperature rise and the impact of entering the defrosting mode. Therefore, it is necessary to detect and obtain the external pipe temperature of the air conditioner (the subsequent process also needs to obtain the external pipe temperature. For the convenience of explanation, the external pipe temperature obtained this time is called the first external pipe temperature), and the first external pipe temperature is compared with the second predetermined temperature to determine whether the air conditioner needs to enter the defrosting mode. The second predetermined temperature changes with the change of the outdoor temperature.

[0051] In S25, when the first outer tube temperature is less than or equal to the second predetermined temperature, it indicates that the outer tube temperature is too low and the surface of the outdoor heat exchanger may have frosted, which will affect the heat exchange efficiency. Therefore, a defrosting operation is required to restore the normal heating function of the air conditioner.

[0052] In one embodiment, if Figure 4 As shown, S20 also includes:

[0053] S26, if the first outer tube temperature T 外管1 Greater than the second predetermined temperature T 预定2 , it is determined whether the running time of the air conditioner reaches the second predetermined time t 预定2 ;

[0054] S27: If the running time of the air conditioner has reached the second predetermined time t 预定2 , then re-obtain the external pipe temperature T of the air conditioner 外管 And as the second outer tube temperature T 外管2 , and the second outer tube temperature T 外管2 The second predetermined temperature T 预定2 Make comparisons;

[0055] S28, if the second outer tube temperature T 外管2 Greater than the second predetermined temperature T 预定2 , then calculate the first outer tube temperature T 外管1 and the second outer tube temperature T 外管2 The second temperature difference T 差值2 ;

[0056] S29, if the second temperature difference T 差值2 Greater than or equal to the second preset difference T 预设差值2 , it confirms that the air conditioner needs to enter defrost mode.

[0057] In this embodiment, the second predetermined time t 预定2 and the second preset difference T 预设差值2 It will change with the operating frequency f0 of the compressor, as shown in Table 1 (can be adjusted according to actual conditions):

[0058] Table 1

[0059] f0 / Hz <![CDATA[t 预定2 / min]]> <![CDATA[T 预设差值2 / ℃]]> f0＜60 50 2 60≤f0＜90 30 3 90≤f0 10 4

[0060] During the operation of the air conditioner, when the compressor is at different operating frequencies, the frost rate of the outdoor heat exchanger of the air conditioner is also different; the lower the operating frequency of the compressor, the slower the outdoor heat exchanger frosts and the slower the rate at which the external pipe temperature decreases. Therefore, when the compressor is at different operating frequencies, the second predetermined time and the second preset difference are also different.

[0061] Assuming that the operating frequency f0 of the compressor is 48 Hz, it can be known from Table 1 that 48 Hz is less than 60 Hz, the second preset time that can be obtained is 50 minutes, and the second preset difference is 2°C. At this time, if the first outer tube temperature is greater than the second preset temperature, it is also necessary to determine whether the operating time of the air conditioner reaches the second preset time of 50 minutes. After the operating time of the air conditioner reaches 50 minutes, the outer tube temperature of the air conditioner is obtained again (the second acquisition, for the sake of convenience, is called the second outer tube temperature), and the second outer tube temperature is compared with the second preset temperature again. When the second outer tube temperature is greater than the second preset temperature, the second temperature difference between the second outer tube temperature and the second preset temperature is calculated, that is, the second temperature difference = the second outer tube temperature - the second preset temperature. At this time, the second temperature difference is compared with the second preset difference of 2°C. When the second temperature difference is greater than or equal to 2°C, it is confirmed that the air conditioner needs to enter defrosting. This is because a large change in the outer tube temperature means that the frost on the outdoor heat exchanger is gradually accumulating, and a defrosting operation is required to maintain a normal heating effect.

[0062] In one embodiment, S20 further includes:

[0063] If the second temperature difference T 差值2 Less than the second preset difference T 预设差值2 , the air conditioner is controlled to maintain the heating mode until the second temperature difference T 差值2 Greater than or equal to the second preset difference T 预设差值2 Or the second outer tube temperature T 外管2 Less than or equal to the second predetermined temperature T 预定2 , it confirms that the air conditioner needs to enter defrost mode.

[0064] In this embodiment, when the second temperature difference is less than the second preset difference, the air conditioner is controlled to maintain the heating mode, thereby avoiding the interference of frequent defrosting operations on the indoor temperature. Frequent defrosting will lead to instability of the indoor temperature, causing the indoor temperature to fluctuate between hot and cold, which will bring an uncomfortable experience to the user. Through such precise judgment and control, the impact of the defrosting operation on the indoor temperature can be minimized while ensuring normal heating, providing the user with a relatively stable and comfortable indoor thermal environment. The entire defrosting judgment process is as follows: Figure 5shown.

[0065] In a specific implementation, the second predetermined temperature T 预定2 The value is taken according to a preset association diagram, wherein the association diagram includes an association relationship between different outdoor temperature ranges and the second predetermined temperature value.

[0066] In this embodiment, a correlation diagram is prepared in advance, and the correlation diagram includes a plurality of different outdoor temperature ranges. For each outdoor temperature range, a second predetermined temperature value corresponding to each outdoor temperature range is set in the correlation diagram. The preset correlation diagram can be set according to Table 2:

[0067] Table 2

[0068] Outdoor temperature range / ℃ <![CDATA[T 预定2 / ℃]]> <![CDATA[5℃≤T 室外 ]]> -3 <![CDATA[0℃≤T 室外 <5℃]]> -6 <![CDATA[-5℃≤T 室外 <0℃]]> -9 <![CDATA[-10℃≤T 室外 <-5℃]]> <![CDATA[T 室外 -6]]> <![CDATA[T 室外 <-10℃]]> <![CDATA[T 室外 -4]]>

[0069] Due to different outdoor temperatures, the temperature of the outer tube during the operation of the air conditioner is also different. The lower the outdoor temperature, the slower the temperature of the outer tube decreases. The outer tube temperature when the outdoor heat exchanger is frosted thickly is also different. Therefore, the outer tube temperature when entering defrosting is also different at different outdoor temperatures. In order to prevent the air conditioner from defrosting when it is just frosted or when the frost is too thick when operating in different outdoor environments, affecting the user's comfort, the value of the second predetermined temperature needs to be set according to the actual situation to ensure user comfort.

[0070] S30: If defrosting is required, the operating frequency of the compressor and the opening of the electronic expansion valve are adjusted to speed up defrosting.

[0071] In this step, a shorter defrost time means that the air conditioner can resume normal heating function more quickly. Since frosting will seriously affect the heat exchange efficiency of the outdoor heat exchanger, thereby affecting the heating effect of the air conditioner, accelerating defrosting can make the heat exchange efficiency of the outdoor heat exchanger return to normal more quickly, thereby improving the heating performance of the air conditioner more quickly, allowing the indoor temperature to reach the temperature set by the user more quickly, and improving the heating efficiency of the entire air conditioner. In specific implementation, the defrost can be accelerated by increasing the operating frequency of the compressor and increasing the opening of the electronic expansion valve.

[0072] In one embodiment, if Figure 6 As shown, S30 includes:

[0073] S31, increasing the operating frequency of the compressor to a first predetermined frequency f1, and increasing the opening of the electronic expansion valve to a first predetermined opening b1;

[0074] S32: If the air conditioner runs for the third predetermined time t 预定3 If the air conditioner is still in defrosting state, the external pipe temperature T of the air conditioner is obtained again. 外管 And as the third outer tube temperature T 外管3 , and the third outer tube temperature T外管3 and the third predetermined temperature T 预定3 Make comparisons;

[0075] S33, if the third outer tube temperature T 外管3 Greater than or equal to the third predetermined temperature T 预定3 , the current operating frequency of the compressor and the current opening of the electronic expansion valve are maintained.

[0076] In this embodiment, after the air conditioner enters defrosting mode, by increasing the operating frequency of the compressor, the refrigerant can release more heat at the outdoor heat exchanger, accelerating the melting speed of the frost layer. This means that the frost layer on the surface of the outdoor heat exchanger can be removed more quickly, shortening the time required for defrosting, enabling the air conditioner to switch back to the normal heating mode from the defrosting mode more quickly, reducing the indoor temperature fluctuation and refrigeration interruption time caused by defrosting, and providing users with a more stable and comfortable indoor environment. At the same time, the opening of the electronic expansion valve is increased to control the flow and pressure of the refrigerant, so that more high-temperature and high-pressure refrigerant flows to the outdoor heat exchanger, thereby providing more heat for defrosting and accelerating the melting of the frost layer. This method of jointly adjusting the operating frequency of the compressor and the opening of the electronic expansion valve can make full use of the energy of the system and make the defrosting process more efficient.

[0077] In specific implementation, when the air conditioner has not entered defrosting mode, the operating frequency of the compressor is f0, and the opening of the electronic expansion valve is b0. The operating frequency of the compressor is increased to the first predetermined frequency f1 (f1 can be 86 Hz), and the opening of the electronic expansion valve is increased to the first predetermined opening b1 (b1 can be 400P). After the air conditioner has been running for the third predetermined time (which can be 3 minutes), it is still in the defrosting state, indicating that the defrosting is not completed at this time and the defrosting time is too long, and the air conditioner has not supplied heat to the room for a long time, resulting in a decrease in the indoor temperature and a poor user experience. At this time, the air conditioner is restarted. The external pipe temperature of the air conditioner is obtained (the third time, for ease of explanation, it is called the third external pipe temperature), and the relationship between the third external pipe temperature and the third predetermined temperature (which can be 2°C) is determined. When the third external pipe temperature is greater than or equal to the third predetermined temperature, the current operating frequency of the compressor (i.e. f1) and the current opening of the electronic expansion valve (i.e. b1) are maintained to continue defrosting. This is because when the third external pipe temperature exceeds 2°C, the frost on the surface of the heat exchanger has almost melted, and the subsequent external pipe temperature rises rapidly, so there is no need to adjust the defrost parameters (i.e. the operating frequency of the compressor and the opening of the electronic expansion valve).

[0078] In one embodiment, if Figure 7 As shown, S30 also includes:

[0079] S34, if the third outer tube temperature T 外管3 Less than the third predetermined temperature T 预定3 , the operating frequency of the compressor is increased to a second predetermined frequency f2;

[0080] S35: If the air conditioner runs for the fourth predetermined time t 预定4 If the defrosting state is still maintained after the defrosting, the opening of the electronic expansion valve is increased to a second predetermined opening b2.

[0081] In this embodiment, when the third external pipe temperature is lower than the third predetermined temperature, the operating frequency of the compressor is increased to the second predetermined frequency f2, wherein f1 is lower than f2, and f2 can be 92Hz. Continuing to increase the operating frequency of the compressor can speed up the defrosting time of the air conditioner. If the air conditioner is still in the defrosting state after running for the fourth predetermined time (which can be 5 minutes), the opening of the electronic expansion valve is increased to b2, wherein b2 is higher than b1, and b2 can be 460P, thereby increasing the refrigerant flow rate and speeding up the defrosting speed until the defrosting is completed. The entire defrosting parameter adjustment process is as follows: Figure 8 shown.

[0082] When the air conditioner is in heating operation, the embodiment of the present invention can enter defrost in time according to the actual operation status of the air conditioner to avoid prolonged defrost time due to thick frost. At the same time, during the defrost period, the operating frequency of the compressor and the opening of the electronic expansion valve can be adjusted in time according to the defrost time and the external pipe temperature to shorten the defrost time, ensure that the indoor temperature does not drop significantly, and improve the thermal comfort of users.

[0083] The embodiment of the present invention further provides a control device for an air conditioner, which is used to execute any embodiment of the control method for an air conditioner. Fig. 9 , Fig. 9 400 is a schematic block diagram of a control device for an air conditioner provided in an embodiment of the present invention. The control device 400 for the air conditioner includes:

[0084] A frost determination unit 410 is used to determine whether frost will form during operation of the air conditioner when the air conditioner is in a heating mode;

[0085] The defrost judging unit 420 is used to obtain the indoor temperature, the set temperature of the air conditioner and the external pipe temperature of the air conditioner after the first predetermined operation time if frost will form, and to judge whether the air conditioner needs to enter defrost mode;

[0086] The adjustment unit 430 is used to adjust the operating frequency of the compressor and the opening of the electronic expansion valve to speed up the defrosting if defrosting is required.

[0087] like Fig.10 As shown, an embodiment of the present invention provides an air conditioner, including a compressor and an electronic expansion valve, and also includes the control device as described above.

[0088] In specific implementation, the air conditioner includes an indoor unit and an outdoor unit. The indoor unit includes an indoor heat exchanger, an indoor fan, an environmental temperature sensor and a first pipe temperature sensor, wherein the environmental temperature sensor is used to detect the temperature of the indoor environment, and the first pipe temperature sensor is used to detect the pipe temperature of the indoor heat exchanger. The outdoor unit includes a compressor, a four-way valve, an outdoor heat exchanger, an electronic expansion valve, an outdoor fan, an exhaust temperature sensor, an environmental temperature sensor and a second pipe temperature sensor, wherein the exhaust temperature sensor is used to detect the exhaust temperature of the compressor, the environmental temperature sensor is used to detect the temperature of the outdoor environment, and the second pipe temperature sensor is used to detect the pipe temperature of the outdoor heat exchanger (i.e., the external pipe temperature). The various pipe temperature sensors are not shown in the figure. Fig.10 Winning bid.

[0089] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A control method for an air conditioner, applied to an air conditioner, wherein the air conditioner comprises a compressor and an electronic expansion valve, characterized in that: The control method comprises: When the air conditioner is in heating mode, determine whether frost will form during operation of the air conditioner; If frost will form, then after the first predetermined time of operation, the indoor temperature, the set temperature of the air conditioner and the temperature of the outer pipe of the air conditioner are obtained, and it is determined whether the air conditioner needs to enter defrosting mode; If defrosting is required, adjust the operating frequency of the compressor and the opening of the electronic expansion valve to speed up defrosting.

2. The control method according to claim 1, characterized in that: When the air conditioner is in the heating mode, determining whether the air conditioner will frost during operation includes: Obtaining the outdoor temperature, and comparing the outdoor temperature with a first predetermined temperature: If the outdoor temperature is lower than the first predetermined temperature, it is confirmed that frost may form during operation of the air conditioner.

3. The control method according to claim 1, characterized in that: If frost will form, then after the first predetermined time of operation, the indoor temperature, the set temperature of the air conditioner and the temperature of the outer pipe of the air conditioner are obtained, and it is determined whether the air conditioner needs to enter defrosting, including: Get the running time of the air conditioner; If the running time of the air conditioner reaches a first predetermined time, the indoor temperature and the set temperature of the air conditioner are obtained, and a first temperature difference between the indoor temperature and the set temperature of the air conditioner is calculated; If the first temperature difference is less than or equal to the first preset difference, it is confirmed that the air conditioner needs to enter defrosting mode; If the first temperature difference is greater than a first preset difference, obtaining an external pipe temperature of the air conditioner as a first external pipe temperature, and comparing the first external pipe temperature with a second preset temperature; If the first outer pipe temperature is less than or equal to the second predetermined temperature, it is confirmed that the air conditioner needs to enter defrosting.

4. The control method according to claim 3, characterized in that: If frost will form, then after the first predetermined time of operation, the indoor temperature, the set temperature of the air conditioner and the external pipe temperature of the air conditioner are obtained, and it is determined whether the air conditioner needs to enter defrosting, and the method further includes: If the first outer pipe temperature is greater than the second predetermined temperature, determining whether the operation time of the air conditioner reaches the second predetermined time; If the operation time of the air conditioner has reached the second predetermined time, reacquiring the external pipe temperature of the air conditioner as the second external pipe temperature, and comparing the second external pipe temperature with the second predetermined temperature; If the second outer tube temperature is greater than the second predetermined temperature, calculating a second temperature difference between the first outer tube temperature and the second outer tube temperature; If the second temperature difference is greater than or equal to the second preset difference, it is confirmed that the air conditioner needs to enter defrosting mode.

5. The control method according to claim 4, characterized in that: If frost will form, then after the first predetermined time of operation, the indoor temperature, the set temperature of the air conditioner and the external pipe temperature of the air conditioner are obtained, and it is determined whether the air conditioner needs to enter defrosting, and the method further includes: If the second temperature difference is less than the second preset difference, the air conditioner is controlled to maintain heating mode operation until the second temperature difference is greater than or equal to the second preset difference or the second outer tube temperature is less than or equal to the second preset temperature, then it is confirmed that the air conditioner needs to enter defrost mode.

6. The control method according to claim 5, characterized in that: The second predetermined temperature is taken according to a preset association diagram, wherein the association diagram includes an association relationship between different outdoor temperature ranges and the second predetermined temperature value.

7. The control method according to claim 1, characterized in that: If defrosting is required, the operating frequency of the compressor and the opening of the electronic expansion valve are adjusted to speed up defrosting, including: Increasing the operating frequency of the compressor to a first predetermined frequency, and increasing the opening of the electronic expansion valve to a first predetermined opening; If the air conditioner is still in the defrosting state after running for the third predetermined time, reacquire the external pipe temperature of the air conditioner and use it as the third external pipe temperature, and compare the third external pipe temperature with the third predetermined temperature; If the third outer pipe temperature is greater than or equal to the third predetermined temperature, the current operating frequency of the compressor and the current opening of the electronic expansion valve are maintained.

8. The control method according to claim 7, characterized in that: If defrosting is required, the operating frequency of the compressor and the opening of the electronic expansion valve are adjusted to accelerate defrosting, and the method further includes: If the third outer pipe temperature is lower than a third predetermined temperature, the operating frequency of the compressor is increased to a second predetermined frequency; If the air conditioner is still in the defrosting state after running for the fourth predetermined time, the opening degree of the electronic expansion valve is increased to the second predetermined opening degree.

9. A control device for an air conditioner, applied to the control method according to any one of claims 1 to 8, characterized in that: include: A frost determination unit, used to determine whether frost will form during operation of the air conditioner when the air conditioner is in a heating mode; A defrost judgment unit, for obtaining the indoor temperature, the set temperature of the air conditioner and the temperature of the outer pipe of the air conditioner after the first predetermined operation time if frost will form, and judging whether the air conditioner needs to enter defrost mode; The adjustment unit is used to adjust the operating frequency of the compressor and the opening of the electronic expansion valve to speed up defrosting if defrosting is required.

10. An air conditioner, comprising a compressor and an electronic expansion valve, characterized in that: Also includes the control device as claimed in claim 9.

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