Air conditioner anti-frost control method, air conditioner and medium

Abstract

The present invention discloses an anti-frost control method for an air conditioner, an air conditioner, and a computer-readable storage medium. The method includes: obtaining the operating state of an outdoor heat exchanger; obtaining the operating state of the outdoor heat exchanger; and performing a preset frost suppression operation when the operating state matches the frost formation critical state of the outdoor heat exchanger. When the air conditioner is in the heating mode and the outdoor heat exchanger is in the frost formation critical state, or when it is determined that the outdoor heat exchanger is in the critical state of about to frost or having frosted a small amount of frost, the present invention takes a preset frost suppression operation to prevent the outdoor heat exchanger from frosting or frosting more. Thus, it can timely determine the frosting trend of the outdoor heat exchanger, defrost when the outdoor heat exchanger is in the frost formation critical state, without causing a large amount of subsequent frosting of the outdoor heat exchanger, reducing the frosting and defrosting times of the outdoor heat exchanger, and further improving the heating effect and operating efficiency of the air conditioner.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning equipment, and particularly to an anti-frost control method for an air conditioner, an air conditioner, and a computer-readable storage medium. Background Art

[0002] During the heating operation of an existing heat pump air conditioner, generally, the target temperature is used as the control target for the compressor frequency. When the indoor temperature differs greatly from the target temperature, the compressor operates at a high frequency. When the indoor temperature reaches the target temperature, the compressor stops.

[0003] However, since the outdoor heat exchanger absorbs heat from the outdoor air, the temperature around the outdoor heat exchanger is relatively low, and water vapor in the air will condense into frost and adhere to the surface of the outdoor heat exchanger, affecting the heat exchange capacity of the outdoor heat exchanger, reducing the heating capacity of the air conditioner, and affecting people's comfort.

[0004] In related technologies, generally, it is only judged whether to defrost after frost has formed or even a large amount of frost has formed. Little mention is made of how to judge the critical state and frost formation trend when frost is about to form or a small amount of frost has formed, so as to prevent more frost from forming. Summary of the Invention

[0005] The main purpose of the present invention is to provide an anti-frost control method for an air conditioner, an air conditioner, and a computer-readable storage medium, aiming to determine the critical state and frost formation trend when the outdoor heat exchanger is about to form frost or has formed a small amount of frost, so as to prevent more frost from forming.

[0006] To achieve the above purpose, the present invention provides an anti-frost control method for an air conditioner, and the anti-frost control method for an air conditioner includes the following steps:

[0007] Obtain the working state of the outdoor heat exchanger;

[0008] When the working state matches the frost formation critical state of the outdoor heat exchanger, perform a preset frost inhibition operation;

[0009] Among them, the determination conditions for the working state to match the frost formation critical state include at least one of the following:

[0010] Within a preset first time period, the temperature difference reduction rate between the middle plate temperature and the outlet plate temperature of the outdoor heat exchanger exceeds the target temperature difference reduction rate, and the exhaust temperature value of the compressor decreases;

[0011] Within a preset second time period, the temperature reduction rate of the middle plate temperature of the outdoor heat exchanger exceeds the first target temperature reduction rate;

[0012] Within a preset third time period, the temperature reduction rate of the middle plate temperature of the indoor heat exchanger exceeds the second target temperature reduction rate;

[0013] Within a preset fourth time period, the power reduction rate of the outdoor fan motor power is greater than the target power reduction rate.

[0014] Optionally, the air conditioner anti-frost control method further includes:

[0015] Obtain the frost formation difficulty of the outdoor heat exchanger in the frost formation critical state;

[0016] Determine the target temperature difference reduction rate, the first target temperature reduction rate, the second target temperature reduction rate, and the target power reduction rate according to the frost formation difficulty.

[0017] Optionally, the frost formation difficulty includes difficult to frost and easy to frost;

[0018] The step of determining the target temperature difference reduction rate, the first target temperature reduction rate, the second target temperature reduction rate, and the target power reduction rate according to the frost formation difficulty includes:

[0019] When the frost formation difficulty is difficult to frost, adjust the target temperature difference reduction rate, the first target temperature reduction rate, the second target temperature reduction rate, and the target power reduction rate with a preset increase amplitude;

[0020] When the frost formation difficulty is easy to frost, adjust the target temperature difference reduction rate, the first target temperature reduction rate, the second target temperature reduction rate, and the target power reduction rate with a preset decrease amplitude.

[0021] Optionally, the step of obtaining the frost formation difficulty of the outdoor heat exchanger in the frost formation critical state includes:

[0022] Obtain the ambient temperature and dew point temperature of the outdoor heat exchanger;

[0023] When the ambient temperature is less than the preset temperature, determine the frost formation difficulty of the frost formation critical state according to the ambient temperature and the dew point temperature.

[0024] Optionally, the step of determining the frost formation difficulty of the frost formation critical state according to the ambient temperature and the dew point temperature includes:

[0025] If the difference between the ambient temperature and the dew point temperature is not greater than the first temperature difference, determine that the frost formation difficulty of the frost formation critical state is easy to frost.

[0026] Optionally, the step of determining the frost formation difficulty of the frost formation critical state according to the ambient temperature and the dew point temperature includes:

[0027] If the difference between the ambient temperature and the dew point temperature is greater than a second temperature difference and not greater than a third temperature difference, it is determined that the difficulty of frosting in the frost formation critical state is relatively difficult to frost.

[0028] Optionally, the preset anti-frost operation includes:

[0029] Maintaining or increasing the rotational speed of the outdoor fan, decreasing the rotational speed of the indoor fan, decreasing the compressor frequency, and / or increasing the evaporation temperature of the refrigerant in the outdoor heat exchanger.

[0030] Optionally, the steps of performing the preset anti-frost operation include:

[0031] Obtaining the ambient temperature, indoor temperature, heating target temperature, middle plate temperature of the indoor heat exchanger, and preset threshold temperature of the middle plate of the indoor heat exchanger where the outdoor heat exchanger is located;

[0032] When the ambient temperature where the outdoor heat exchanger is located is greater than 0°C and the indoor temperature reaches the heating target temperature, controlling the outdoor fan to operate at the rotational speed in the heating mode for a preset duration;

[0033] When the middle plate temperature of the indoor heat exchanger is greater than the preset threshold temperature of the middle plate of the indoor heat exchanger, decreasing the rotational speed of the indoor fan and / or decreasing the compressor frequency.

[0034] In addition, to achieve the above object, the present application further provides an air conditioner, which includes: a memory, a processor, and an air conditioner anti-frost control program stored on the memory and executable on the processor. When the air conditioner anti-frost control program is executed by the processor, the steps of the air conditioner anti-frost control method described in any one of the above are implemented.

[0035] In addition, to achieve the above object, the present application further provides a computer-readable storage medium, on which an air conditioner anti-frost control program is stored. When the air conditioner anti-frost control program is executed by a processor, the steps of the air conditioner anti-frost control method described in any one of the above are implemented.

[0036] An air conditioner anti-frost control method proposed by the present invention. When the air conditioner is in the heating mode and the outdoor heat exchanger is in the frost formation critical state, and it is determined that the outdoor heat exchanger is in the critical state of about to frost or having frosted a small amount of frost, a preset anti-frost operation is taken to prevent the outdoor heat exchanger from frosting or frosting more.

[0037] Compared with the method of determining whether to defrost the outdoor heat exchanger after the outdoor heat exchanger has frosted or even frosted heavily, the present application can timely determine the frosting trend of the outdoor heat exchanger, defrost when the outdoor heat exchanger is in the critical state of frosting, without causing subsequent heavy frosting of the outdoor heat exchanger, reducing the frosting and defrosting times of the outdoor heat exchanger, and further improving the heating effect and operating efficiency of the air conditioner. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic structural diagram of an operating device of the hardware operating environment involved in the embodiment solution of the present invention;

[0039] Figure 2 It is a schematic flowchart of an embodiment of a method for preventing frosting control of an air conditioner according to the present invention.

[0040] The realization, functional characteristics and advantages of the object of the present invention will be further described in conjunction with the embodiments with reference to the drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0042] The main solution of the embodiment of the present invention is: obtaining the working state of the outdoor heat exchanger; when the working state matches the critical frosting state of the outdoor heat exchanger, performing a preset anti-frosting operation; wherein, the determination conditions for the working state to match the critical frosting state include at least one of the following: within a preset first time period, the temperature difference reduction rate between the middle plate temperature and the outlet plate temperature of the outdoor heat exchanger exceeds a preset first rate, and the exhaust temperature value at the compressor exhaust port decreases; within a preset second time period, the temperature reduction rate of the middle plate temperature of the outdoor heat exchanger exceeds a preset second rate, the preset second rate is greater than the preset first rate, and the preset second time period is greater than the preset first time period; within a preset third time period, the temperature reduction rate of the middle plate temperature of the indoor heat exchanger exceeds a preset first rate, and the preset third time period is greater than the preset second time period; within a preset fourth time period, the power reduction rate of the outdoor side fan motor power is greater than a preset power reduction rate.

[0043] In the related art, usually, it is determined whether to defrost after frosting or even heavy frosting has occurred. However, little mention is made of how to judge the critical state and frosting trend when frosting is about to occur or a small amount of frosting has occurred to prevent more frosting.

[0044] The present invention provides the above-mentioned solution. Compared with the method of determining whether to defrost the outdoor heat exchanger after the outdoor heat exchanger has already frosted or even frosted a large amount, it can timely determine the frosting trend of the outdoor heat exchanger, defrost when the outdoor heat exchanger is in a critical frosting state, without causing subsequent large-scale frosting of the outdoor heat exchanger, reducing the frosting and defrosting times of the outdoor heat exchanger, and further improving the heating effect and operating efficiency of the air conditioner.

[0045] Refer to Figure 1 , Figure 1 which is a schematic structural diagram of an operating device for the hardware operating environment involved in the solution of the embodiment of the present invention.

[0046] As Figure 1 shown, the operating device may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. Among them, the communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 may include a display screen (Display) and an input unit such as a keyboard (Keyboard). Optionally, the user interface 1003 may further include a standard wired interface and a wireless interface. The network interface 1004 may optionally include a standard wired interface and a wireless interface (such as a wireless fidelity (WI-FI) interface). The memory 1005 may be a high-speed random access memory (Random Access Memory, RAM) or a stable non-volatile memory (Non-Volatile Memory, NVM), such as a disk memory. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0047] Those skilled in the art can understand that Figure 1 the structure shown in

[0048] As Figure 1 shown, in the memory 1005 as a storage medium, there may be included an operating system, a data storage module, a network communication module, a user interface module, and a computer program.

[0049] In Figure 1In the operating device shown, the network interface 1004 is mainly used for data communication with other devices; the user interface 1003 is mainly used for data interaction with users; the processor 1001 and the memory 1005 in the operating device of the present invention can be arranged in the operating device. The operating device calls the computer program stored in the memory 1005 through the processor 1001 and performs the following operations:

[0050] Obtain the working state of the outdoor heat exchanger;

[0051] When the working state matches the frosting critical state of the outdoor heat exchanger, perform a preset frosting suppression operation;

[0052] Wherein, the determination conditions for the matching of the working state and the frosting critical state include at least one of the following:

[0053] Within a preset first time period, the temperature difference reduction rate between the middle plate temperature and the outlet plate temperature of the outdoor heat exchanger exceeds the target temperature difference reduction rate, and the exhaust temperature value of the compressor decreases;

[0054] Within a preset second time period, the temperature reduction rate of the middle plate temperature of the outdoor heat exchanger exceeds the first target temperature reduction rate;

[0055] Within a preset third time period, the temperature reduction rate of the middle plate temperature of the indoor heat exchanger exceeds the second target temperature reduction rate;

[0056] Within a preset fourth time period, the power reduction rate of the outdoor fan motor power is greater than the target power reduction rate.

[0057] An embodiment of the present invention provides an air conditioner anti-frost control method. Refer to Figure 2 , Figure 2 which is a schematic flow chart of an embodiment of an air conditioner anti-frost control method of the present invention.

[0058] In this embodiment, the air conditioner anti-frost control method includes the following steps:

[0059] Step S10: Obtain the working state of the outdoor heat exchanger.

[0060] Currently, when the air conditioner is operating in the frosting-prone temperature range in the heating mode and the compressor operates at high frequency, the evaporation pressure decreases. Since the lower the evaporation pressure, the lower the evaporation temperature, the evaporation temperature of the refrigerant decreases, resulting in easy frosting on the surface of the outdoor heat exchanger. And as long as there is frosting, the performance of the heat pump air conditioner will decline and the heat exchange will deteriorate. To reach the target temperature, the frequency will continue to increase to ensure the heat exchange capacity, but at the same time, it will further accelerate frosting, forming a vicious cycle. After reaching the target temperature, the compressor stops, and heat cannot be obtained from the air source. To break out of the vicious cycle, heat needs to be absorbed from the indoor side and transferred to the outdoor heat exchanger during defrosting, resulting in some heat dissipating to the outside, thus causing a large waste of the heating capacity of the heat pump air conditioner and a poor heating effect.

[0061] Currently, in the related art, it is mostly about how to judge the presence of frost when there is already relatively thick frost. After there is very thick frost, it is determined whether defrosting is needed through temperature. It does not consider the critical frosting state, nor the judgment conditions for the critical frosting state, and even less the defrosting measures for the critical frosting state.

[0062] In this application, it is to judge whether frosting may occur, judge the frosting trend at the critical state of about to frost and with a little bit of frost, and prevent more frost from forming. By obtaining the working state of the outdoor heat exchanger, the frosting trend of the outdoor heat exchanger is determined in a timely manner, and defrosting is carried out when the outdoor heat exchanger is in the critical frosting state. Among them, the parameters characterizing the working state of the outdoor heat exchanger include the temperature difference between the middle plate temperature and the outlet plate temperature of the outdoor heat exchanger (the middle temperature and the outlet temperature of the outdoor heat exchanger), the exhaust temperature value at the compressor exhaust port (the exhaust temperature value of the high-pressure gaseous refrigerant discharged from the compressor exhaust port), the middle plate temperature of the indoor heat exchanger (the middle temperature of the indoor heat exchanger), the power of the outdoor fan motor, etc.

[0063] Step S20: When the working state matches the critical frosting state of the outdoor heat exchanger, perform a preset frost inhibition operation.

[0064] Among them, the determination conditions for the matching of the working state and the critical frosting state include at least one of the following:

[0065] Condition 1: Within a preset first time period, the temperature difference reduction rate between the middle plate temperature and the outlet plate temperature of the outdoor heat exchanger exceeds the target temperature difference reduction rate, and the exhaust temperature value of the compressor decreases;

[0066] Condition 2: Within a preset second time period, the temperature reduction rate of the middle plate temperature of the outdoor heat exchanger exceeds the first target temperature reduction rate;

[0067] Condition 3: Within a preset third time period, the temperature reduction rate of the middle plate temperature of the indoor heat exchanger exceeds the second target temperature reduction rate;

[0068] Condition 4: Within a preset fourth time period, the power reduction rate of the outdoor fan motor power is greater than the target power reduction rate.

[0069] If the outdoor heat exchanger is frosted, its heat exchange effect will deteriorate. Since the air temperature outside the frost-covered pipe decreases, the refrigerant inside the outdoor heat exchanger also decreases synchronously, resulting in incomplete evaporation of the refrigerant inside the pipe. There will not be as much gas evaporated as when there is no frosting, and the superheat (the temperature difference between the outlet and the middle of the coil) becomes lower. Similarly, it will cause the temperature at the suction port of the compressor to decrease. The temperature at the discharge port of the compressor is related to the temperature at the suction port, and the change in the temperature at the suction port is not as obvious as the change in the temperature at the discharge port. Therefore, the temperature at the discharge port of the compressor is selected as one of the judgment conditions. Thus, the frosting critical state of the outdoor heat exchanger can be determined by checking whether the working state matches Condition 1. Among them, the two conditions that the temperature difference reduction rate between the middle and outlet of the outdoor heat exchanger exceeds the preset first rate and the discharge temperature value at the discharge port of the compressor decreases are consistent and belong to two phenomena with the same principle.

[0070] When the outdoor heat exchanger is in the frosting critical state, in order to achieve the same heating effect, the temperature difference between the ambient temperature and the refrigerant temperature will be increased. Since the ambient temperature cannot be changed, only the temperature of the refrigerant and the heat transfer medium can be reduced, resulting in a decrease in the middle temperature of the outdoor heat exchanger and the temperature of the outdoor heat exchanger. Thus, the frosting critical state of the outdoor heat exchanger can be determined by checking whether the working state matches Condition 2. Due to the reduction of the judgment conditions, in order to ensure the accuracy of the judgment, when determining whether the outdoor heat exchanger is in the frosting critical state based on the single middle temperature of the outdoor heat exchanger, the preset second rate is greater than the preset first rate, and the preset second time period is greater than the preset first time period, and it is determined with a longer time and a greater change rate.

[0071] Similarly, when the heat exchange effect deteriorates due to the outdoor heat exchanger being in the frosting critical state, the outdoor temperature decreases synchronously, causing the indoor temperature to decrease, and resulting in a decrease in the middle temperature of the indoor heat exchanger on the indoor side. Thus, the frosting critical state of the outdoor heat exchanger can be determined by checking whether the working state matches Condition 3. Since the decrease in the indoor temperature is not as large as the decrease in the outdoor temperature, the preset third time period is greater than the preset second time period.

[0072] When the outdoor heat exchanger is in the frosting critical state, the frost will block the outdoor heat exchanger a little bit, resulting in a smaller air volume, which is equivalent to less work done by the fan motor, so the power is reduced. Thus, the frosting critical state of the outdoor heat exchanger can be determined by checking whether the working state matches Condition 4.

[0073] In this embodiment, when the air conditioner is in the heating mode and the outdoor heat exchanger is in the critical state of frosting, that is, when it is determined that the outdoor heat exchanger is about to frost or has frosted a small amount, a preset anti-frost operation is taken to prevent the outdoor heat exchanger from frosting or frosting more.

[0074] Compared with the method of judging whether to defrost the outdoor heat exchanger after the outdoor heat exchanger has already frosted or even frosted a large amount, the present application can timely determine the frosting trend of the outdoor heat exchanger, defrost when the outdoor heat exchanger is in the critical state of frosting, without causing subsequent large-scale frosting of the outdoor heat exchanger, reducing the frosting and defrosting times of the outdoor heat exchanger, and further improving the heating effect and operating efficiency of the air conditioner.

[0075] The parameter values in the above various determination conditions cannot be selected too large, otherwise it will be impossible to judge frosting, nor can they be too small, otherwise it is easy to cause misjudgment. They need to be selected based on the data of frosting tests and research. In this embodiment, the parameter values in the above various determination conditions are all obtained through simulation calculations.

[0076] Optionally, Condition 1 is: It is judged by the change of the temperature of the middle plate, the outlet plate temperature in the outdoor unit heat exchanger and the exhaust temperature value at the compressor exhaust port. When the actions of other components remain unchanged, when the temperature difference reduction rate between the middle plate temperature and the outlet plate temperature of the outdoor heat exchanger exceeds 1 °C / min for 1 min and the exhaust temperature value at the compressor exhaust port decreases simultaneously, then the critical state of frosting of the outdoor heat exchanger is judged and there is a risk of frosting.

[0077] Condition 2 is: It is judged by the change of the temperature of the middle plate in the outdoor unit heat exchanger. When the actions of other components remain unchanged, when the temperature reduction rate of the middle plate temperature of the outdoor heat exchanger exceeds 2 °C / min for 3 min, then the critical state of frosting of the outdoor heat exchanger is judged and there is a risk of frosting.

[0078] Condition 3 is: It is judged by the change of the temperature of the middle plate in the indoor unit heat exchanger. When the actions of other components remain unchanged, when the temperature reduction rate of the middle plate temperature of the indoor heat exchanger exceeds 1 °C / min for 6 min, then the critical state of frosting of the outdoor heat exchanger is judged and there is a risk of frosting.

[0079] Condition 4 is: It is judged by the change of the outdoor side motor power. When the actions of other components remain unchanged, when the power reduction rate of the outdoor side fan motor power is greater than 1% / min, then the critical state of frosting of the outdoor heat exchanger is judged and there is a risk of frosting.

[0080] It should be noted that when the outdoor heat exchanger is in the critical state of frosting, all of the above four conditions may be satisfied, but the possible values may not be applicable to all situations. Only taking one may cause misjudgment, and taking two will be more accurate. In this embodiment, the number of conditions selected is not limited.

[0081] An embodiment of the present invention provides a frost prevention control method for an air conditioner. In the second embodiment of the present invention, the frost prevention control method for the air conditioner further includes:

[0082] Obtain the frost formation difficulty level of the outdoor heat exchanger in the frost formation critical state;

[0083] Determine the target temperature difference reduction rate, the first target temperature reduction rate, the second target temperature reduction rate, and the target power reduction rate according to the frost formation difficulty level.

[0084] Optionally, the step of obtaining the frost formation difficulty level of the outdoor heat exchanger in the frost formation critical state includes:

[0085] Obtain the ambient temperature and the dew point temperature of the outdoor heat exchanger;

[0086] When the ambient temperature is less than a preset temperature, determine the frost formation difficulty level in the frost formation critical state according to the ambient temperature and the dew point temperature.

[0087] Optionally, the step of determining the frost formation difficulty level in the frost formation critical state according to the ambient temperature and the dew point temperature includes:

[0088] If the difference between the ambient temperature and the dew point temperature is not greater than a first temperature difference, determine that the frost formation difficulty level in the frost formation critical state is easy to frost.

[0089] Optionally, the step of determining the frost formation difficulty level in the frost formation critical state according to the ambient temperature and the dew point temperature includes:

[0090] If the difference between the ambient temperature and the dew point temperature is greater than a second temperature difference and not greater than a third temperature difference, determine that the frost formation difficulty level in the frost formation critical state is relatively difficult to frost.

[0091] Optionally, the frost formation difficulty level includes relatively difficult to frost and easy to frost;

[0092] The step of determining the target temperature difference reduction rate, the first target temperature reduction rate, the second target temperature reduction rate, and the target power reduction rate according to the frost formation difficulty level includes:

[0093] When the frost formation difficulty level is relatively difficult to frost, adjust the target temperature difference reduction rate, the first target temperature reduction rate, the second target temperature reduction rate, and the target power reduction rate with a preset increase amplitude;

[0094] When the degree of frost formation is easy, adjust the target temperature difference reduction rate, the first target temperature reduction rate, the second target temperature reduction rate, and the target power reduction rate at a preset reduction amplitude.

[0095] The ambient temperature T is the dry-bulb temperature, which refers to the temperature directly exposed to the air for detection; the dew point temperature Td is the temperature at which the air is cooled to saturation, and below this temperature, condensation water will form on the surface of the object. Determine a preset temperature at which frosting will not occur. For example, when the temperature is greater than the preset temperature by 6 - 10 °C, frosting generally does not occur, and the preset temperature can be taken as 8 °C. When the ambient temperature is less than the preset temperature, determine the degree of frost formation difficulty in the frost formation critical state based on the ambient temperature and the dew point temperature. This degree of frost formation difficulty can be divided into easy to frost, relatively easy to frost, relatively difficult to frost, and difficult to frost. Finally, determine the target temperature difference reduction rate, the first target temperature reduction rate, the second target temperature reduction rate, and the target power reduction rate according to the degree of frost formation difficulty, so as to adaptively adjust the frost formation judgment conditions for different degrees of frost formation difficulty, thereby improving the accuracy of determining the frost formation critical state.

[0096] The condition for the degree of frost formation difficulty of easy to frost is that the ambient temperature T - the dew point temperature Td ≤ the first temperature difference, where the first temperature difference can be 3 °C. When the degree of frost formation difficulty is easy to frost, adjust the target temperature difference reduction rate, the first target temperature reduction rate, the second target temperature reduction rate, and the target power reduction rate, and adjust the parameter values in the frost formation critical state judgment conditions at a preset reduction amplitude. Among them, the preset reduction amplitude can be 50%, and reduce the parameter values in each judgment condition to half of the default value before adjustment.

[0097] The condition for the degree of frost formation difficulty of relatively easy to frost is that the first temperature difference < the ambient temperature T - the dew point temperature Td ≤ the second temperature difference, where the first temperature difference can be 3 °C and the second temperature difference can be 5 °C. When the degree of frost formation difficulty is relatively easy to frost, do not adjust the target temperature difference reduction rate, the first target temperature reduction rate, the second target temperature reduction rate, and the target power reduction rate, and do not adjust the parameter values in the frost formation critical state judgment conditions, and judge whether the working state of the outdoor heat exchanger matches the frost formation critical state of the outdoor heat exchanger with the default parameter values.

[0098] The satisfaction condition for the frosting difficulty level that is relatively difficult to frost is the second temperature difference < ambient temperature T - dew point temperature Td ≤ the third temperature difference, where the second temperature difference can be 5°C and the third temperature difference can be 8°C. When the frosting difficulty level is relatively difficult to frost, adjust the target temperature difference reduction rate, the first target temperature reduction rate, the second target temperature reduction rate, and the target power reduction rate, and adjust the parameter values in the judgment condition of the frosting critical state with a preset increase amplitude. Among them, the preset increase amplitude can be 20%, and increase the parameter values in each judgment condition to 120% of the default value before adjustment.

[0099] The satisfaction condition for the frosting difficulty level that is difficult to frost is ambient temperature T - dew point temperature Td > the third temperature difference, where the third temperature difference can be a preset temperature that is determined in advance and will not frost. For example, the third temperature difference can be the preset temperature, taking 8°C. When the frosting difficulty level is difficult to frost, it is determined that the outdoor heat exchanger is not in the frosting critical state, and the preset anti-frost operation is not executed, and defrosting and anti-frosting are not required.

[0100] An embodiment of the present invention provides an air conditioner anti-frost control method. In the third embodiment of the present invention, the preset anti-frost operation includes:

[0101] Maintain or increase the rotational speed of the outdoor fan, decrease the rotational speed of the indoor fan, decrease the compressor frequency, and / or increase the evaporation temperature of the refrigerant in the outdoor heat exchanger.

[0102] Optionally, the step of executing the preset anti-frost operation includes:

[0103] Obtain the ambient temperature, indoor temperature, heating target temperature, middle plate temperature of the indoor heat exchanger, and the preset threshold temperature of the middle plate of the indoor heat exchanger where the outdoor heat exchanger is located;

[0104] When the ambient temperature where the outdoor heat exchanger is located is greater than 0°C and the indoor temperature reaches the heating target temperature, control the outdoor fan to operate at the rotational speed in the heating mode for a preset duration;

[0105] When the middle plate temperature of the indoor heat exchanger is greater than the preset threshold temperature of the middle plate of the indoor heat exchanger, decrease the rotational speed of the indoor fan and / or decrease the compressor frequency.

[0106] In this embodiment, various embodiments of providing anti-frost are provided.

[0107] 1. Maintain the rotation speed of the outdoor fan: When the ambient temperature where the outdoor heat exchanger is located is greater than 0°C and the indoor temperature reaches the heating target temperature, control the outdoor fan to maintain the rotation speed during the heating mode for a preset duration. Since the ambient temperature > 0°C, the frost formed on the outdoor heat exchanger can be directly melted by enhancing heat exchange, without the need for the unit to provide additional energy. When the compressor stops, the outdoor fan does not need to reduce its frequency and can continue to operate for a period of time to enhance heat exchange for defrosting.

[0108] 2. Increase the rotation speed of the outdoor fan: By increasing the rotation speed to increase the flow rate, the same heat exchange amount can be achieved without reducing the temperature difference between the refrigerant in the outdoor heat exchanger tube and the ambient temperature to suppress frosting. Because the heat exchange deteriorates during frosting, to achieve the same heat exchange amount, the heat exchange is enhanced by increasing the air volume, so that the evaporation temperature does not decrease and thus frosting does not occur (to achieve the same heat exchange amount, the heat exchange area can be increased, the temperature difference can be increased, and the flow rate can be increased).

[0109] 3. Reduce the rotation speed of the indoor fan and reduce the compressor frequency: When the temperature of the middle plate of the indoor heat exchanger is greater than the preset threshold temperature of the middle plate of the indoor heat exchanger, reducing the rotation speed of the indoor fan can increase the indoor condensation temperature and increase the outdoor evaporation temperature; because the pipe temperature is relatively high and no cold air will be blown, the evaporation temperature is increased by reducing the compressor frequency.

[0110] 4. Increase the evaporation temperature of the refrigerant in the outdoor heat exchanger: The bypass valve of the suction and discharge bypass can be opened to increase the evaporation temperature. The refrigerant can also be heated by turning on the low-pressure side electric auxiliary heating to increase the evaporation temperature. Some units will tie a heating belt at the suction port. Part of the heat exchange of the outdoor heat exchanger comes from electric heating and part comes from the air. Without this part of electric heating, the heat exchange will be poor, and with this part of electric heating, the heat exchange is better and the evaporation temperature can also be increased.

[0111] In addition, an embodiment of the present invention further provides an air conditioner, which includes: a memory, a processor, and an air conditioner anti-frost control program stored on the memory and executable on the processor. When the air conditioner anti-frost control program is executed by the processor, the steps of the air conditioner anti-frost control method described in any one of the above are implemented.

[0112] In addition, an embodiment of the present invention further provides a computer-readable storage medium, which is characterized in that an air conditioner anti-frost control program is stored on the computer-readable storage medium. When the air conditioner anti-frost control program is executed by a processor, the steps of the air conditioner anti-frost control method described in any one of the above are implemented.

[0113] It should be noted that in this article, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent in such a process, method, article or system. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or system including that element.

[0114] The serial numbers of the above embodiments of the present invention are only for description and do not represent the superiority or inferiority of the embodiments.

[0115] Through the description of the above embodiments, those skilled in the art can clearly understand that the above embodiment methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product is stored in a storage medium as described above (such as ROM / RAM, magnetic disk, optical disk), and includes several instructions for causing a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in various embodiments of the present invention.

[0116] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A method for controlling anti-frosting of an air conditioner, characterized in that, The air conditioner anti-frost control method includes the following steps: Obtain the operating state of the outdoor heat exchanger; When the operating state matches the frosting critical state of the outdoor heat exchanger, perform a preset anti-frost operation, where the preset anti-frost operation includes: maintaining or increasing the rotational speed of the outdoor-side fan, decreasing the rotational speed of the indoor-side fan, decreasing the compressor frequency, and / or increasing the evaporation temperature of the refrigerant in the outdoor heat exchanger; Among them, the determination conditions for the operating state to match the frosting critical state include at least one of the following: Within a preset first time period, the rate of decrease in the temperature difference between the middle plate temperature and the outlet plate temperature of the outdoor heat exchanger exceeds the target temperature difference decrease rate, and the exhaust temperature value of the compressor decreases; Within a preset second time period, the rate of decrease in the middle plate temperature of the outdoor heat exchanger exceeds the first target temperature decrease rate; Within a preset third time period, the rate of decrease in the middle plate temperature of the indoor heat exchanger exceeds the second target temperature decrease rate; Within a preset fourth time period, the rate of decrease in the power of the outdoor-side fan motor is greater than the target power decrease rate.

2. The air conditioner anti-frost control method according to claim 1, wherein The air conditioner anti-frost control method further includes: Obtain the frosting difficulty level of the outdoor heat exchanger in the frosting critical state; Determine the target temperature difference decrease rate, the first target temperature decrease rate, the second target temperature decrease rate, and the target power decrease rate according to the frosting difficulty level.

3. The air conditioner defrosting control method according to claim 2, wherein The frosting difficulty level includes difficult to frost and easy to frost; The step of determining the target temperature difference decrease rate, the first target temperature decrease rate, the second target temperature decrease rate, and the target power decrease rate according to the frosting difficulty level includes: When the frosting difficulty level is difficult to frost, adjust the target temperature difference decrease rate, the first target temperature decrease rate, the second target temperature decrease rate, and the target power decrease rate by a preset increase amplitude; When the frosting difficulty level is easy to frost, adjust the target temperature difference decrease rate, the first target temperature decrease rate, the second target temperature decrease rate, and the target power decrease rate by a preset decrease amplitude.

4. The air conditioner anti-frost control method according to claim 2, characterized in that, The step of obtaining the frosting difficulty level of the outdoor heat exchanger in the frosting critical state includes: Obtain the ambient temperature and dew point temperature of the outdoor heat exchanger; When the ambient temperature is less than the preset temperature, determine the frosting difficulty level of the frosting critical state according to the ambient temperature and the dew point temperature.

5. The air conditioner defrosting control method according to claim 4, wherein The step of determining the frosting difficulty level of the frosting critical state according to the ambient temperature and the dew point temperature includes: If the difference between the ambient temperature and the dew point temperature is not greater than the first temperature difference, determine that the frosting difficulty level of the frosting critical state is easy to frost.

6. The air conditioner anti-frost control method according to claim 4, characterized in that The step of determining the frosting difficulty level of the frosting critical state according to the ambient temperature and the dew point temperature includes: If the difference between the ambient temperature and the dew point temperature is greater than the second temperature difference and not greater than the third temperature difference, determine that the frosting difficulty level of the frosting critical state is difficult to frost.

7. The anti-frost control method for an air conditioner according to claim 1, characterized in that The step of performing the preset anti-frost operation includes: Obtain the ambient temperature where the outdoor heat exchanger is located, the indoor temperature, the heating target temperature, the middle plate temperature of the indoor heat exchanger, and the preset threshold temperature of the middle plate of the indoor heat exchanger; When the ambient temperature where the outdoor heat exchanger is located is greater than 0°C and the indoor temperature reaches the heating target temperature, control the outdoor-side fan to operate at the rotation speed in the heating mode for a preset duration; When the middle plate temperature of the indoor heat exchanger is greater than the preset threshold temperature of the middle plate of the indoor heat exchanger, reduce the rotation speed of the indoor-side fan and / or reduce the compressor frequency.

8. An air conditioner, characterized in that, The air conditioner includes: a memory, a processor, and an air conditioner anti-frost control program stored on the memory and executable on the processor. When the air conditioner anti-frost control program is executed by the processor, the steps of the air conditioner anti-frost control method according to any one of claims 1 to 7 are implemented.

9. A computer-readable storage medium, characterized in that, An air conditioner anti-frost control program is stored on the computer-readable storage medium. When the air conditioner anti-frost control program is executed by the processor, the steps of the air conditioner anti-frost control method according to any one of claims 1 to 7 are implemented.

Images