A control method and device of an air conditioner and the air conditioner

Abstract

The embodiment of the present application provides a control method and device of an air conditioner and the air conditioner. The control method judges whether the air conditioner will frost when the air conditioner is in a heating mode. When the air conditioner will frost, the indoor temperature, the set temperature of the air conditioner and the outer pipe temperature of the air conditioner are detected. Whether the air conditioner needs to defrost is judged according to the three temperatures. During defrosting, the defrosting time is shortened by adjusting the running frequency of the compressor and the opening of the electronic expansion valve, so as to avoid the indoor temperature from being reduced due to the long defrosting time.

Description

Technical Field

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

[0002] In low-temperature conditions, when the air conditioner is in heating mode, a defrost operation is required to ensure its normal operation and efficient heating performance. In the prior art, the air conditioner usually determines whether to enter the defrost 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 conditions of the air conditioner will show obvious differences. Specifically, when the user sets the wind speed to medium or low, 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 during defrosting. Accordingly, the time required for defrosting will be greatly extended. During the defrost 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 including a compressor and an electronic expansion valve. 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 is expected, the indoor temperature, the set temperature of the air conditioner and the temperature of the external pipe of the air conditioner are obtained after the first predetermined time of operation, and it is determined whether the air conditioner needs to enter defrost 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, for determining whether frost will form on the air conditioner during operation when the air conditioner is in heating mode;

[0011] a defrost determination unit for obtaining the indoor temperature, the set temperature of the air conditioner, and the temperature of the external pipe of the air conditioner after a first predetermined operation time if frost is expected, and determining whether the air conditioner needs to enter a 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] An embodiment of the present invention provides a control method, device and air conditioner for an air conditioner. The control method determines whether frost will form when the air conditioner is in heating mode. When frost will form, the control method detects the indoor temperature, the set temperature and the external pipe temperature of the air conditioner during the operation of the air conditioner, and determines whether the air conditioner needs to enter defrost based on these three temperatures. During defrost, the defrost 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 excessive defrost time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these 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] Figure 9 A schematic block diagram of a control device for an air conditioner provided in an embodiment of the present invention;

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

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

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

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

[0030] See also Figure 1 An 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 steps 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 operating in low-temperature conditions, heating mode needs to be activated, and it is necessary to determine whether frost will form during operation. This allows for proactive measures to prevent a thick frost layer from affecting the heat exchange efficiency of the outdoor heat exchanger. If the frost condition is not promptly determined, when frost accumulates on the surface of the outdoor heat exchanger, it will increase thermal resistance, hindering the transfer of heat from the outdoor air to the refrigerant, resulting in a decrease in heat exchange efficiency, which in turn affects the air conditioner's heating capacity. Furthermore, when frost is severe, the air conditioning system may frequently enter defrost mode. During the defrost process, the air conditioner typically suspends or reduces heating. The indoor temperature will drop due to the air conditioner's defrost operation. Especially in cold weather, these temperature fluctuations can cause discomfort to the user. Therefore, it is necessary to determine and control frost formation in advance to reduce switching between air conditioning modes, ensure consistent 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 discovered in advance, specifically, 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 frost will form during the operation of the air conditioner.

[0036] The first predetermined temperature can be set to 5°C. When the outdoor temperature is lower than this predetermined temperature, it indicates that the outdoor environment is cold and the air conditioner is more likely to frost. If 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 air conditioner's operating parameters) to reduce the impact of frost on the air conditioner's heating performance, making the indoor temperature more stable and improving user comfort.

[0037] In a specific embodiment, a threshold for the rate of decrease of the outdoor heat exchanger tube temperature, such as 0.5°C / min, can be set. The air conditioner calculates the rate of change of the outdoor heat exchanger tube temperature over a period of time (e.g., the last 5 minutes). If the tube temperature decrease rate exceeds this threshold, it indicates that the tube temperature is decreasing too quickly, indicating a potential for frosting. Furthermore, an absolute temperature threshold for the outdoor heat exchanger tube temperature, such as -2°C, can be set. If the outdoor heat exchanger tube temperature falls below this absolute temperature threshold, it also indicates that frosting is likely 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 、Set temperature of air conditioner T 设 And the external pipe temperature T of the air conditioner 外管 , and judge whether the air conditioner needs to enter defrost;

[0039] In this step, the difference between the indoor temperature and the air conditioner's set temperature reflects the air conditioner's current heating performance, while the air conditioner's external pipe temperature reflects the frost condition of the outdoor heat exchanger. These three temperatures allow for more accurate determination of defrost timing. For example, if the indoor temperature differs significantly from the set temperature, indicating that the air conditioner's heating performance is not yet meeting user requirements, even if the external pipe temperature indicates a risk of frost, defrosting can be appropriately delayed to prioritize indoor heating needs. Conversely, if the indoor temperature is close to the set temperature and the external pipe temperature indicates severe frost, defrosting can be performed in advance to prevent further frost buildup and subsequent heating effects.

[0040] In addition, this 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 incorrect defrost judgments due to short-term temperature fluctuations or data instability in the early stage 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 confirms that the air conditioner needs to enter defrost 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 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 is set to start timing from the time 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. At this time, the air conditioner enters the defrost mode without affecting user comfort. The first preset difference may be 2°C. Thereafter, the air conditioner enters the defrost mode after each operation time △m (△m may be 30 minutes. This recommended value can avoid frequent defrosting in a short period of time and prevent thick frost from forming after long operation, which would result in a prolonged defrost time). While ensuring indoor temperature comfort, the air conditioner enters the defrost mode quickly to avoid thick frost from forming due to long operation, which would result in a prolonged defrost time and thus affect the indoor temperature.

[0050] In S24, if the first temperature difference is greater than the first preset difference, it indicates that the indoor temperature is not high and is in the rising stage. Considering the rate of indoor temperature increase and the impact of defrosting, it is necessary to detect and obtain the air conditioner's external pipe temperature (subsequent processes will also require obtaining the external pipe temperature. For ease of explanation, this external pipe temperature obtained is referred to as the first external pipe temperature). The first external pipe temperature is then compared with the second predetermined temperature to determine whether the air conditioner needs to defrost. The second predetermined temperature varies with changes in the outdoor temperature.

[0051] In S25, when the first external pipe temperature is less than or equal to the second predetermined temperature, it indicates that the external pipe 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, the 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 air conditioner's outdoor heat exchanger 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 compressor operating frequency f0 is 48 Hz, according to Table 1, 48 Hz < 60 Hz, the second predetermined time that can be obtained is 50 minutes, and the second predetermined difference is 2°C. At this time, if the first external tube temperature is greater than the second predetermined temperature, it is necessary to determine whether the air conditioner operating time has reached the second predetermined time of 50 minutes. After the air conditioner operating time reaches 50 minutes, the air conditioner external tube temperature is obtained again (the second acquisition, for ease of explanation, referred to as the second external tube temperature), and the second external tube temperature is again compared with the second predetermined temperature. When the second external tube temperature is greater than the second predetermined temperature, a second temperature difference between the second external tube temperature and the second predetermined temperature is calculated, that is, second temperature difference = second external tube temperature - second predetermined temperature. At this time, the second temperature difference is again compared with the second predetermined 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 defrost. This is because a large external tube temperature change means that frost is gradually accumulating on the outdoor heat exchanger, and a defrost 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. If defrosting is performed frequently, it 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 this 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 associations between different outdoor temperature ranges and the second predetermined temperature value.

[0066] In this embodiment, a correlation diagram is prepared in advance. The correlation diagram includes multiple 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 external pipe temperature of the air conditioner during operation also varies. The lower the outdoor temperature, the slower the external pipe temperature decreases. The external pipe temperature also varies when the outdoor heat exchanger is frosted thickly. Therefore, the external pipe temperature at which defrost begins will also vary depending on the outdoor temperature. To ensure that the air conditioner operates in different outdoor environments without defrosting immediately after frost or when frost is too thick, which would affect user comfort, the second predetermined temperature value needs to be set based on actual conditions 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 defrost 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 user-set temperature 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 the 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 defrost mode, the compressor's operating frequency is increased, allowing the refrigerant to release more heat at the outdoor heat exchanger, accelerating the melting of the frost layer. This means that the frost layer on the surface of the outdoor heat exchanger can be cleared more quickly, shortening the time required for defrosting, allowing the air conditioner to switch back to normal heating mode more quickly, reducing indoor temperature fluctuations and cooling interruptions caused by defrosting, and providing users with a more stable and comfortable indoor environment. Simultaneously, the opening of the electronic expansion valve is increased to control the refrigerant flow and pressure, allowing more high-temperature, high-pressure refrigerant to flow to the outdoor heat exchanger, thereby providing more heat for defrosting and accelerating the melting of the frost layer. This combined adjustment of the compressor operating frequency and the electronic expansion valve opening fully utilizes the system's energy, making the defrost process more efficient.

[0077] In specific implementation, when the air conditioner has not entered the defrost state, 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 86Hz), 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 defrost state, indicating that the defrost is not completed at this time and the defrost time is too long. In addition, 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. Obtain the external pipe temperature of the air conditioner (the third time, for ease of explanation, it is called the third external pipe temperature), and determine the relationship between the third external pipe temperature and the third predetermined temperature (which can be 2°C). When the third external pipe temperature is greater than or equal to the third predetermined temperature, maintain the current operating frequency of the compressor (i.e., f1) and the current opening of the electronic expansion valve (i.e., b1) 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 , then 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 air conditioner is still in the defrosting state after the frost is removed, 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 conditions of the air conditioner, thereby avoiding prolonging the 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, thereby shortening the defrost time, ensuring that the indoor temperature does not drop significantly, and improving the user's thermal comfort.

[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. Figure 9 , Figure 9 : is a schematic block diagram of a control device for an air conditioner provided by an embodiment of the present invention. The control device 400 for the air conditioner includes:

[0084] The 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 determination 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 determine whether the air conditioner needs to enter the 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 accelerate defrosting if defrosting is required.

[0087] like Figure 10 As shown, 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.

[0088] In specific implementation, the air conditioner includes two parts: 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). Among them, the various pipe temperature sensors are not shown in the figure. Figure 10 The winning bid was awarded.

[0089] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection 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 includes: 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 running for a first predetermined time, 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 the defrost mode; specifically, the steps include: obtaining the running time of the air conditioner; if the running time of the air conditioner reaches the first predetermined time, obtaining the indoor temperature and the set temperature of the air conditioner, and calculating a first temperature difference between the indoor temperature and the set temperature of the air conditioner; if the first temperature difference is less than or equal to the first preset difference, confirming that the air conditioner needs to enter the defrost mode; if the first temperature difference is greater than the first preset difference, obtaining the outer pipe temperature of the air conditioner and using it as the first outer pipe temperature, and comparing the first outer pipe temperature with a second predetermined temperature; if the first outer pipe temperature is less than or equal to the second predetermined temperature, confirming that the air conditioner needs to enter the defrost 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 frost will form during operation of the air conditioner includes: Obtain the outdoor temperature and compare the outdoor temperature with a first predetermined temperature: If the outdoor temperature is lower than the first predetermined temperature, it is determined that frost may form during operation of the air conditioner.

3. The control method according to claim 1, wherein: If frost is formed, 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 defrost mode, 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 a second predetermined time; If the operation time of the air conditioner has reached the second predetermined time, re-acquiring the external pipe temperature of the air conditioner and using it 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 defrost mode.

4. The control method according to claim 3, characterized in that: If frost is formed, 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 defrost mode, 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 pipe temperature is less than or equal to the second predetermined temperature, then it is confirmed that the air conditioner needs to enter defrost mode.

5. The control method according to claim 4, characterized in that: The second predetermined temperature is determined according to a preset association diagram, wherein the association diagram includes associations between different outdoor temperature ranges and the second predetermined temperature values.

6. 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, reacquiring the external pipe temperature of the air conditioner as the third external pipe temperature, and comparing the third external pipe temperature with the third predetermined temperature; If the third external pipe temperature is greater than or equal to a third predetermined temperature, the current operating frequency of the compressor and the current opening of the electronic expansion valve are maintained.

7. The control method according to claim 6, 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, increasing the operating frequency of the compressor 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.

8. A control device for an air conditioner, applied to the control method according to any one of claims 1 to 7, characterized in that: include: a frost determination unit, for determining whether frost will form on the air conditioner during operation when the air conditioner is in heating mode; The defrost judgment unit is configured to obtain the indoor temperature, the set temperature of the air conditioner, and the temperature of the outer pipe of the air conditioner after a first predetermined operation time if frost will form, and to determine whether the air conditioner needs to enter a defrost state; specifically, the unit comprises: obtaining the operation time of the air conditioner; if the operation time of the air conditioner reaches the first predetermined time, obtaining the indoor temperature and the set temperature of the air conditioner, and calculating a first temperature difference between the indoor temperature and the set temperature of the air conditioner; if the first temperature difference is less than or equal to the first predetermined difference, determining that the air conditioner needs to enter a defrost state; if the first temperature difference is greater than the first predetermined difference, obtaining the outer pipe temperature of the air conditioner as the first outer pipe temperature, and comparing the first outer pipe temperature with a second predetermined temperature; if the first outer pipe temperature is less than or equal to the second predetermined temperature, determining that the air conditioner needs to enter a defrost state; 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.

9. An air conditioner comprising a compressor and an electronic expansion valve, characterized in that: Also includes the control device as claimed in claim 8.

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