Air conditioner defrosting control method and system

Abstract

The invention relates to the technical field of air conditioner control, in particular to an air conditioner defrosting control method and system.The air conditioner defrosting control method comprises the following steps that a, in a heating mode, the evaporation fan driving power of an evaporator is calibrated, and an evaporation fan driving power reference value is obtained; b, under the operation of the heating mode, whether the current actual operation wind speed of the evaporation fan is larger than or equal to the wind speed judgment effective value of the evaporation fan or not is judged, and the wind speed blocking power value under the current wind speed condition of the evaporation fan is calculated; c, under the operation of the heating mode, sampling and calculating to obtain the actual driving power of the evaporation fan, and judging whether the actual driving power of the evaporation fan is greater than or equal to the wind speed plugging power value and lasts for more than T0 time or not, if not, judging that the state is frostless, and if yes, entering a power triggering defrosting mode of the evaporation fan; and d, according to the defrosting condition of the defrosting mode triggered by the power of the evaporation fan, whether the blocking type of the evaporation fan is frost blocking or filth blocking is judged, and judgment is more accurate.

Description

Technical Field

[0001] This invention relates to the field of air conditioning control technology, and in particular to an air conditioning defrosting control method and system. Background Art

[0002] For heat pump air conditioners, frost will form on the evaporator in heating mode, requiring defrosting. Current control systems typically use ambient temperature, fin temperature, saturated evaporation temperature, ring-fin temperature difference, cumulative heating time, and defrosting interval as the criteria for triggering defrosting. Currently, there are two main methods for determining these defrosting criteria: Method 1: Frosting of the wing rings: a. Compression mechanism hot running time > defrost detection delay time; b. The cumulative operating time of the compressor during heating is greater than the defrosting interval; c. Fin temperature ≤ defrosting entry temperature; d. Ambient temperature - fin temperature > ring-fin temperature difference.

[0003] The second method: Low-pressure defrosting: a. Compression mechanism hot running time > low-pressure defrost detection delay time; b. The cumulative operating time of the compressor during heating is greater than the low-pressure defrosting interval; c. Fin temperature ≤ low-pressure defrosting inlet temperature; d. (Low-pressure) saturated evaporation temperature ≤ low-pressure defrosting entry temperature.

[0004] The first method mentioned above mainly uses the difference between the ambient temperature and the fin temperature to determine whether defrosting is needed. However, this method is greatly affected by the installation location of the fin temperature sensor and is also related to whether the liquid distribution in the evaporator is uniform. Therefore, it cannot accurately determine whether defrosting is required.

[0005] The second method above, which uses the (low-pressure) saturated evaporation temperature to determine whether defrosting is needed, is greatly affected by factors such as the amount of refrigerant charged into the system, climate conditions, and the opening of the electronic expansion valve, and therefore cannot accurately determine whether defrosting is required.

[0006] Therefore, neither of the above two defrosting criteria can accurately determine whether frost has formed on the evaporator or the thickness of the frost. In different humidity environments or when the complete consistency of the entire machine production cannot be guaranteed, frost-free defrosting may occur, leading to misjudgment and wrong entry into the defrosting logic. This can result in a decline in user experience due to frequent defrosting, low unit energy efficiency, or triggering faults such as high system pressure and compressor drive overcurrent during frost-free defrosting.

[0007] For example, Chinese Patent Application No. 202211390012.0 discloses an air conditioner defrosting control method, control device, and air conditioner. The control method includes: when the air conditioner enters defrosting mode, controlling the outdoor fan to run at a high fan speed and detecting the outdoor ambient temperature value T_outer_loop; based on the outdoor ambient temperature value T_outer_loop, controlling the air conditioner to enter the outdoor fan adjustment mode; detecting the outdoor coil temperature value T_outer_pan, and / or the outdoor fan operating current value I, and the rated current value Is when the outdoor fan speed first reaches the rated speed at the high fan speed; based on the outdoor coil temperature value T_outer_pan, and / or the operating current value I, and the rated current value Is, determining whether the air conditioner meets the outdoor fan shutdown conditions; if so, controlling the outdoor fan to shut down.

[0008] There are many control technologies similar to the patented technology mentioned above. They usually use current for detection and control. However, the current is highly unstable, which can easily lead to false alarms, especially in places with poor installation environments where the frequency and amplitude of voltage and current fluctuations are relatively high, making it difficult to make accurate judgments. Summary of the Invention

[0009] The purpose of this invention is to provide a more accurate air conditioning defrosting control method and system.

[0010] The above-mentioned objective of the present invention is achieved through the following technical solution: an air conditioning defrosting control method, comprising the following steps: Step a: In heating mode, calibrating the evaporator fan drive power and obtaining a reference value for the evaporator fan drive power; Step b: Under heating mode operation, determining whether the current actual operating wind speed of the evaporator fan is greater than or equal to the valid value of the evaporator fan wind speed judgment; if not, using conventional defrosting methods to determine whether to enter defrosting mode; if so, extracting the reference value of the evaporator fan drive power corresponding to the current evaporator fan wind speed and calculating the wind speed blocking power value under the current evaporator fan wind speed conditions; Step c: Under heating mode operation, sampling and calculating the actual drive power of the evaporator fan, and determining whether the actual drive power of the evaporator fan is greater than or equal to the wind speed blocking power value and lasts for more than T0 time; if not, determining a frost-free state; if so, entering the evaporator fan power-triggered defrosting mode; Step d: Based on the defrosting situation of the evaporator fan power-triggered defrosting mode, determining whether the evaporator fan blockage is frost blockage or dirt blockage.

[0011] As a preferred embodiment of the present invention, in step d, the process for determining the type of evaporator fan blockage is as follows: In the evaporator fan power-triggered defrosting mode, if the time between the end of the last defrosting and the end of the previous defrosting is greater than the continuous defrosting interval T1, it is determined to be frost blockage and defrosting begins; if the time between the end of the last defrosting and the end of the previous defrosting is less than the continuous defrosting interval T1, it is determined to be dirt blockage and false defrosting begins, and the number of times is recorded. If the cumulative number of false defrosting due to dirt blockage is less than 2 within the time period n*T1, it is temporarily determined to be frost blockage and defrosting begins; if the cumulative number of false defrosting due to dirt blockage is greater than or equal to 2 within the time period n*T1, it is determined to be dirt blockage, the evaporator fins are dirt blockage, the defrosting judgment condition is switched to the normal defrosting mode, and evaporator cleaning begins.

[0012] As a preferred embodiment of the present invention, the evaporator cleaning specifically includes marking the evaporator fins as dirty and clogged, prompting the user to clean the evaporator and remove the markings. The method of removing the markings includes manual removal by the user and automatic removal. The automatic removal method is that when the actual driving power of the evaporator fan is detected to be less than the wind speed blocking power value for a duration of T2 or more, the markings are automatically removed.

[0013] As a preferred embodiment of the present invention, the specific process of calibrating the evaporator fan drive power in step a includes: step a1, after the unit is installed on-site, heating is performed and the first routine defrosting is carried out; step a2, defrosting is completed and it is ensured that there is no frost on the evaporator fins; step a3, before resuming heating, a reference target wind speed is configured for the evaporator fan and it is operated according to the reference target wind speed. Under the current frost-free installation environment, the drive power corresponding to the evaporator fan operating according to the reference target wind speed is calibrated to obtain the reference value of the evaporator fan drive power.

[0014] As a preferred embodiment of the present invention, if the benchmark target wind speed is preset to two or more levels, then the corresponding benchmark value of the evaporator fan drive power has two or more values.

[0015] As a preferred embodiment of the present invention, the calibration method for the evaporator fan drive power reference value is as follows: the evaporator fan runs at each preset reference target wind speed level from low to high, and the wind speed is maintained at each wind speed level for a time T3. The first half of the time T3 is used to wait for the wind speed to stabilize, and the power of the evaporator fan is sampled to obtain the evaporator fan drive power reference value for each preset reference target wind speed level.

[0016] As a preferred embodiment of the present invention, when the actual wind speed of the evaporator fan is between two adjacent reference target wind speeds, the reference value of the evaporator fan drive power corresponding to the current actual wind speed of the evaporator fan is calculated by linearization.

[0017] As a preferred embodiment of the present invention, the linearization approximation calculation specifically involves: using the reference values ​​of the evaporator drive power corresponding to the two wind speed settings adjacent to the current actual wind speed of the evaporator, and constructing a linear equation with the evaporator wind speed as the independent variable and the reference value of the evaporator drive power as the dependent variable based on these two values, and substituting the current actual wind speed of the evaporator into the equation to approximately calculate the reference value of the evaporator drive power corresponding to the current actual wind speed of the evaporator.

[0018] As a preferred embodiment of the present invention, the wind speed blocking power value = the evaporator drive power reference value corresponding to the actual wind speed of the current evaporator * (100% + wind speed power blocking increment percentage).

[0019] An air conditioning defrosting control system includes a calibration module, an effective wind speed judgment module, a drive power judgment module, and a blockage type judgment module. The calibration module defines and calibrates a reference value for the drive power of an evaporator fan. The effective wind speed judgment module, under heating mode operation, determines whether the actual operating wind speed of the evaporator fan is greater than or equal to the effective value of the evaporator fan wind speed judgment. If not, it uses a conventional defrosting method to determine whether to enter defrosting mode. If so, it extracts the reference value of the evaporator fan drive power corresponding to the current evaporator fan wind speed and calculates the wind speed blockage power value under the current evaporator fan wind speed condition. The drive power judgment module, under heating mode operation, samples and calculates the actual drive power of the evaporator fan and determines whether the actual drive power of the evaporator fan is greater than or equal to the wind speed blockage power value and lasts for more than T0 time. If not, it is determined to be a frost-free state. If so, it enters the evaporator fan power-triggered defrosting mode. The blockage type judgment module determines whether the evaporator fan blockage is frost blockage or dirt blockage based on the defrosting situation in the evaporator fan power-triggered defrosting mode.

[0020] The beneficial effects of this invention are as follows: This application proposes a method to collect and calculate the driving power of the evaporator fan, using this power condition as the primary condition for determining defrosting, and using the conventional annular fin temperature difference condition as an auxiliary supplementary condition. Based on the approximate linear proportional relationship between the driving power of the evaporator fan and the fan load (i.e., the thickness of frost on the fins) under certain actual operating wind speed conditions, by collecting and calculating the driving power of the evaporator fan, the frost condition of the evaporator fins can be more accurately characterized.

[0021] It mainly consists of the collected baseline value of the evaporator fan drive power, the collected actual operating drive power of the evaporator fan, the operating time of the heating compressor, and judgment conditions such as the ring fin difference.

[0022] The main principle is based on the approximately linear proportional relationship between the driving power of the evaporator fan at a certain wind speed and the wind resistance and static pressure caused by the varying thickness of frost on the evaporator fins. By collecting the actual driving power of the evaporator fan, the thickness of frost on the evaporator fins can be determined. The evaporator fan driving power detection requires data collection, calculation, and filtering under certain wind speed conditions. This data is then compared with a baseline value of the fan driving power collected when the fins are not frosted. When the actual operating driving power of the evaporator fan exceeds a certain threshold percentage of the baseline value, it can be determined that the frost thickness on the evaporator is relatively thick, thus achieving the purpose of determining whether to initiate defrosting.

[0023] It can accurately determine whether defrosting is required by detecting the drive power of the evaporator fan, and whether defrosting is required when there is frost: 1. It uses the direct proportional relationship between the drive power of the evaporator fan and the thickness of the frost to accurately determine whether defrosting is required by detecting the drive power of the evaporator fan; 2. It can determine whether the evaporator is dirty or clogged by detecting the drive power of the evaporator fan. Attached Figure Description

[0024] Figure 1 This is the basic flowchart of Example 1; Figure 2 Is Figure 1 A flowchart of a specific embodiment based on this; Figure 3 This is a system module diagram of Embodiment 2. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings.

[0026] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

[0027] Example 1, such as Figure 1 , Figure 2As shown, an air conditioner defrosting control method includes the following steps: Step a: In heating mode, calibrate the evaporator fan drive power and obtain a reference value for the evaporator fan drive power; Step b: In heating mode, determine whether the current actual operating wind speed of the evaporator fan is greater than or equal to the valid value of the evaporator fan wind speed judgment. If not, use the conventional defrosting method to determine whether to enter defrosting mode. If valid, extract the reference value of the evaporator fan drive power corresponding to the current evaporator fan wind speed and calculate the wind speed blocking power value under the current evaporator fan wind speed condition; Step c: In heating mode, sample and calculate the actual drive power of the evaporator fan, and determine whether the actual drive power of the evaporator fan is greater than or equal to the wind speed blocking power value and lasts for more than T0 time. If not, determine that it is a frost-free state. If valid, enter the evaporator fan power-triggered defrosting mode; Step d: Based on the defrosting situation of the evaporator fan power-triggered defrosting mode, determine whether the evaporator fan blockage is frost blockage or dirt blockage. The above-mentioned conventional defrosting method judgment includes the existing conventional ring-fin differential defrosting method judgment or low-pressure defrosting method judgment, etc. In this embodiment, the ring-fin differential defrosting method judgment is preferred. The key feature of this solution lies in its novel design of evaporator fan power-triggered defrosting. This design utilizes the evaporator fan's drive power, as changes in power directly reflect energy output and provide a relatively accurate basis for judging frost blockage. Therefore, a baseline evaporator fan drive power value is set as a basic reference. Heating will cause frost formation and blockage, but at the same fan speed, the power required is higher. Thus, the fan speed blockage power value needs to be calculated and compared with the actual drive power for accurate judgment. Specifically, when the actual evaporator fan drive power is greater than or equal to the fan speed blockage power value and remains so for more than T0 time, the evaporator fan power-triggered defrosting mode is activated. This new mode can distinguish between frost blockage and dirt blockage, and then perform defrosting or cleaning based on the result. As the names suggest, frost blockage is caused by frost formation, while dirt blockage is caused by debris such as garbage or sand, which increases the power required. This prevents false frost alarms and unnecessary defrosting operations, and also facilitates the execution of ordinary defrosting procedures. The T0 time can be selected as 4-6 minutes, which is a suitable length, and can be further optimized to 5 minutes.

[0028] Preferably, in step d, the process for determining the type of evaporator fan blockage is as follows: In the evaporator fan power-triggered defrosting mode, if the time between the end of the next defrost and the end of the previous defrost is greater than the continuous defrosting interval T1, it is determined to be frost blockage, and defrosting begins; if the time between the end of the next defrost and the end of the previous defrost is less than the continuous defrosting interval T1, it is determined to be dirt blockage and false defrosting is recorded. If the cumulative number of false defrosting due to dirt blockage is less than 2 within n*T1 time, it is temporarily determined to be frost blockage, and defrosting begins. If the cumulative number of false defrosting due to dirt blockage is greater than or equal to 2 within n*T1 time, it is determined to be dirt blockage, the evaporator fins are dirt blocked, the defrosting judgment condition is switched to the normal defrosting mode, and evaporator cleaning begins. The interval T1 can be set to 10-20 minutes, preferably 15 minutes. n*T1 is a natural multiple, which can be set to 3-5 times, preferably 4, so n*T1 can preferably be one hour. A temporary assessment of frost blockage means that the current time point is frost blockage, but since the cumulative number of occurrences is based on a period of time prior to the current time point, it is possible that a dirt blockage will occur again in a few minutes, resulting in more than two instances. In such cases, a dirt blockage will be immediately assessed, and the dirt blockage treatment will be carried out.

[0029] Specifically, the evaporator cleaning process includes marking the evaporator fins for dirt and clogging, prompting the user to clean the evaporator and remove the dirt and clogging marks. The removal of these marks can be done manually or automatically. The automatic removal method involves automatically removing the dirt and clogging marks when the actual driving power of the evaporator fan is detected to be less than the blocking power value for a duration of T2 or more. T2 is preferably 8-15 minutes, and more preferably 10 minutes.

[0030] Furthermore, in step a, the specific process of calibrating the evaporator fan drive power includes: Step a1, after the unit is installed on-site, heating is performed and the first routine defrosting is carried out; Step a2, defrosting is completed and it is ensured that there is no frost on the evaporator fins; Step a3, before resuming heating, a reference target wind speed is configured for the evaporator fan and it is operated according to the reference target wind speed. Under the current frost-free installation environment, the drive power corresponding to the evaporator fan operating according to the reference target wind speed is calibrated to obtain the reference value of the evaporator fan drive power.

[0031] Wherein, if the preset target wind speed has two or more levels, then the corresponding value of the evaporator fan drive power reference value has two or more values. Theoretically, the more the better, but in actual use, the target wind speed is preferably five to ten levels, for example, level 7 is sufficient. The corresponding evaporator fan drive power reference value is also 7.

[0032] The calibration method for the evaporator fan drive power reference value is as follows: the evaporator fan is operated sequentially at each preset reference target fan speed level from low to high, and the fan speed is maintained at each fan speed level for a time T3. The first half of T3 is used to wait for the fan speed to stabilize, and the second half of T3 is used to sample the evaporator fan power and obtain the evaporator fan drive power reference value for each preset reference target fan speed level. T3 is preferably 40-80 seconds, and more preferably 1 minute.

[0033] Furthermore, when the actual wind speed of the evaporator fan is between two adjacent target wind speeds, the reference value of the evaporator fan drive power corresponding to the current actual wind speed is calculated by linearization.

[0034] The linearization approximation calculation specifically involves: using the reference values ​​of the evaporator drive power corresponding to the two wind speed settings adjacent to the current actual wind speed of the evaporator, and constructing a linear equation with the evaporator wind speed as the independent variable and the reference value of the evaporator drive power as the dependent variable, and substituting the current actual wind speed of the evaporator into the equation to approximately calculate the reference value of the evaporator drive power corresponding to the current actual wind speed.

[0035] In addition, the wind speed blocking power value = the evaporator drive power base value corresponding to the actual wind speed of the current evaporator * (100% + wind speed power blocking increment percentage).

[0036] Based on the above implementation schemes, a specific implementation case is given below, namely an air conditioning defrosting control method, which includes the following steps: Step S1: In cooling mode, there is no need to perform defrosting judgment; the system operates according to normal cooling logic. Step S2: In heating mode, read the power-down memory parameters in the EEPROM (Electrically Erasable Programmable Read-Only Memory) and determine whether the evaporator fan drive power reference value calibration flag has been set to 1. Here, or later, setting it to 1 means that it has been achieved, and not achieving it means it is in the 0 state. When the evaporator fan drive power reference value calibration has not yet been performed, first determine whether to enter defrost according to the existing conventional ring-fin differential defrosting method, that is, the defrosting judgment method is based on the temperature difference between the environment and the fins. After the conventional defrosting conditions are met for the first time and the defrosting logic is executed once, before resuming heating operation, at this time, the evaporator fins are not frosted, and the unit is already installed on site. Under the current certain wind speed and on-site installation environment conditions, the current evaporator fan drive power can be used as the power reference value for evaporator fan drive power reference value calibration. The current certain wind speed is a fan speed preset based on the on-site installation environment and the unit's ability to operate stably. It is advisable to preset multiple speeds later, which will be explained in detail in step S3.

[0037] Step S3: Enter the fan power reference value calibration logic. The evaporator fan runs at each preset target wind speed level from low to high. The wind speed is maintained at each wind speed level for 1 minute. The first 30 seconds are used to wait for the wind speed to stabilize. The power of the evaporator fan is sampled and filtered to calculate the average value in the last 30 seconds. The fan power reference value of each preset target wind speed level obtained by sampling and calculation is saved to EEPROM. The fan power reference value calibration flag is set to 1. For example, the preset target wind speed of the evaporator fan can be set to five levels: 1.2m / s, 1.4m / s, 1.6m / s, 1.8m / s and 2.0m / s. The evaporator fan power reference value corresponding to the five wind speed levels can be obtained by sampling and calculation. Step S4: When running in heating mode, the driving power of the evaporator fan is sampled and calculated in real time. It is determined whether the actual operating speed of the evaporator fan is greater than or equal to the effective value of the fan speed judgment. Since the driving power does not change significantly when the evaporator fan speed is too low, when the above judgment condition is not met, that is, when the actual speed of the evaporator fan is too low, the conventional ring-fin differential defrosting method is still used to determine whether to enter defrosting. The effective value of the fan speed judgment is preferably not less than the lowest speed corresponding to the fan power reference value, such as 1.2 m / s. Step S5: When the heating mode is running, if the actual current evaporator fan speed is greater than or equal to the valid value of the evaporator fan speed judgment, for example, if the actual current evaporator fan speed is greater than or equal to 1.2 m / s, the next step is to determine the reference value of the evaporator fan drive power. This is because in actual operation, the evaporator fan speed may be limited due to various reasons such as excessively high fan-driven radiator temperature or low input voltage. The actual evaporator fan speed may not reach the preset target speed. In this case, the reference value of the drive power corresponding to the actual current evaporator fan speed needs to be calculated approximately using linearization. The calculation method is to retrieve the fan power reference values ​​corresponding to the two speed settings adjacent to the actual current evaporator fan speed stored in the EEPROM. Based on these two values, with the evaporator fan speed as the independent variable and the evaporator fan drive power reference value as the dependent variable, a linear equation is constructed. The actual current evaporator fan speed is then substituted into the equation to approximately calculate the reference value of the drive power corresponding to the actual current evaporator fan speed.

[0038] Step S6: Based on the driving power benchmark value calculated in step S5, calculate the wind speed blocking power value under the current wind speed condition. The wind speed blocking power value = driving power benchmark value corresponding to the actual wind speed of the current evaporator fan * (100% + wind speed power blocking increment percentage). The wind speed power blocking increment percentage needs to be determined based on the specific unit system, structural design, and actual experimental test of the fan model. For example, it is advisable to set the wind speed power blocking increment percentage between 20% and 30%.

[0039] Step S7: When running in heating mode, compare the actual driving power of the evaporator fan calculated from the sampling with the wind speed blocking power value. If the actual driving power of the evaporator fan is greater than or equal to the wind speed blocking power value, and this condition persists for 5 minutes, the evaporator fan power trigger defrost flag is set to 1. Otherwise, the evaporator fan power trigger defrost flag is set to 0.

[0040] Step S8: When the defrosting trigger flag for the evaporator fan power is set to 0, it is determined to be a frost-free state, and defrosting is temporarily not initiated. At this time, the conventional annular fin differential defrosting method plus the longest defrosting fallback time interval is used to determine whether to initiate defrosting. This prevents defrosting from being delayed due to abnormal sampling of the actual drive power of the evaporator fan or an unreasonable setting of the wind speed power blocking increment percentage.

[0041] Step S9: When the defrosting flag is set to 1 when the evaporator fan power trigger is activated, it is determined that the evaporator fins may be blocked by frost or dirt. If the evaporator fin dirt blockage flag is 0 at this time and more than 15 minutes have passed since the last defrost, it is determined to be frost blockage, and the defrosting logic is executed. If the evaporator fin dirt blockage flag is 0 at this time and less than 15 minutes have passed since the last defrost, the cumulative value of false defrosting due to dirt blockage is incremented by 1. If the cumulative value of false defrosting due to dirt blockage is less than 2 times within 1 hour, it is temporarily determined to be frost blockage, and the defrosting logic is executed. If the cumulative value of false defrosting due to dirt blockage is ≥ 2 times within 1 hour, it is determined to be evaporator fin dirt blockage, the evaporator fin dirt blockage flag is set to 1, and the defrosting judgment condition is switched to the conventional annular differential defrosting mode.

[0042] Step S10: When the evaporator fin dirt blockage mark is set to 1, an alarm code is displayed to prompt the user to clean the evaporator. When the user manually removes the evaporator fin dirt blockage mark or when the actual drive power of the evaporator fan is detected to be less than the wind speed blocking power value for 10 minutes, the evaporator fin dirt blockage mark is set to 0.

[0043] The above control method can better determine defrosting, with higher accuracy, and is more suitable for use in relatively harsh environments, such as places with severe wind, sand and fog, remote rural areas with unstable voltage, etc. Compared with traditional methods, the method of this application has a lower error rate.

[0044] Example 2, as Figure 3As shown, an air conditioning defrosting control system includes a calibration module, an effective wind speed judgment module, a drive power judgment module, and a blockage type judgment module. The calibration module is used to define and calibrate a reference value for the evaporator fan drive power of an evaporator. The effective wind speed judgment module is used to determine whether the actual operating wind speed of the evaporator fan is greater than or equal to the effective value of the evaporator fan wind speed judgment under heating mode. If not, the system uses a conventional defrosting method to determine whether to enter defrosting mode. If so, the system extracts the reference value of the evaporator fan drive power corresponding to the current evaporator fan wind speed and calculates the wind speed blockage power value under the current evaporator fan wind speed condition. The drive power judgment module is used to sample and calculate the actual drive power of the evaporator fan under heating mode and determine whether the actual drive power of the evaporator fan is greater than or equal to the wind speed blockage power value and lasts for more than T0 time. If not, the system is determined to be in a frost-free state. If so, the system enters the evaporator fan power-triggered defrosting mode. The blockage type judgment module is used to determine whether the evaporator fan blockage is frost blockage or dirt blockage based on the defrosting situation in the evaporator fan power-triggered defrosting mode.

[0045] The specific operations performed by each of the above modules are the various steps involved in Example 1. In this way, the system matches the aforementioned method and has corresponding physical modules to implement it.

[0046] 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. An air conditioner defrosting control method, characterized in that: The following steps are involved: Step a, in heating mode, calibrate the evaporator fan driving power of the evaporator and obtain the evaporator fan driving power reference value; step b, in heating mode, determine whether the current evaporator fan actual operating wind speed is ≥ the evaporator fan wind speed to determine whether the effective value is established, if not, use the conventional defrosting method to determine whether to enter defrosting, if yes, extract the evaporator fan driving power reference value corresponding to the current evaporator fan wind speed, and calculate the wind speed blocking power value under the current evaporator fan wind speed condition; step c, in heating mode, sample and calculate to obtain the evaporator fan actual driving power, and determine whether the evaporator fan actual driving power is ≥ the wind speed blocking power value and lasts for more than T0 time, if not, determine it to be frost-free, if yes, enter the evaporator fan power triggered defrost mode; step d, according to the defrosting situation of the evaporator fan power triggered defrost mode, determine whether the type of evaporator fan blockage is frost blockage or dirty blockage.

2. The air conditioner defrosting control method according to claim 1, characterized in that: In step d, the judgment process of the type of evaporator fan blockage is specifically as follows: in the evaporator fan power-triggered defrost mode, if the time from the end of the next defrost to the previous defrost is greater than the continuous defrost interval T1, it is judged as frost blockage and enters defrosting; if the time from the end of the next defrost to the previous defrost is less than the continuous defrost interval T1, it is judged as dirty blockage and false defrosting and the number of times is recorded, and if the cumulative number of dirty blockage and false defrosting times within the time n*T1 is less than 2 times, it is temporarily judged as frost blockage and enters defrosting; if the cumulative number of dirty blockage and false defrosting times within the time n*T1 is greater than or equal to 2 times, it is judged as dirty blockage, the evaporator fins are dirty and blocked, the defrost judgment condition is switched to the conventional defrost mode, and the evaporator cleaning is entered.

3. The air conditioner defrosting control method according to claim 2, characterized in that: The evaporator cleaning specifically includes marking the evaporator fins that are dirty and blocked, prompting the user to clean the evaporator and removing the evaporator fin dirty and blocked mark, wherein the methods for removing the evaporator fin dirty and blocked mark include a user manual release method and an automatic release method. The automatic release method is that when it is detected that the actual driving power of the evaporator fan is less than the wind speed blocking power value for a duration of more than T2, the evaporator fin dirty and blocked mark is automatically released.

4. The air conditioner defrosting control method according to claim 1, characterized in that: In step a, the specific process of calibrating the evaporator fan drive power includes: step a1, heating and performing the first routine defrosting after the on-site installation of the unit is completed; step a2, defrosting is completed and it is ensured that there is no frost on the evaporator fins; step a3, before resuming heating, the evaporator fan is configured with a reference target wind speed and operates according to the reference target wind speed. The corresponding drive power when the evaporator fan operates according to the reference target wind speed in the current frost-free installation environment is calibrated to obtain the evaporator fan drive power reference value.

5. The air conditioner defrosting control method according to claim 4, characterized in that: The reference target wind speed is preset at more than two levels, and the corresponding reference value of the evaporator fan driving power has more than two values.

6. The air conditioner defrosting control method according to claim 5, characterized in that: The calibration method of the evaporator fan driving power reference value is: the evaporator fan runs at each preset reference target wind speed level from low to high in sequence, and the wind speed is kept running for T3 time at each wind speed level, wherein the first half of T3 time is used to wait for the wind speed to stabilize, and the second half of T3 time starts to sample the evaporator fan power and obtain the evaporator fan driving power reference value for each preset reference target wind speed level.

7. The air conditioner defrosting control method according to claim 5, characterized in that: When the actual wind speed of the evaporator fan is between two adjacent reference target wind speeds, the reference value of the evaporator fan driving power corresponding to the current actual wind speed of the evaporator fan is calculated by linear approximation.

8. The air conditioner defrosting control method according to claim 7, characterized in that: The linear approximate calculation is specifically as follows: the evaporator fan drive power reference value corresponding to the two wind speed gears adjacent to the current evaporator fan actual wind speed is used, based on these two point values, the evaporator fan wind speed is used as the independent variable, and the evaporator fan drive power reference value is used as the dependent variable to make a linear equation, and the current evaporator fan actual wind speed is substituted into it to approximately calculate the evaporator fan drive power reference value corresponding to the current evaporator fan actual wind speed.

9. The air conditioner defrosting control method according to claim 7, characterized in that: The wind speed blocking power value=the evaporator fan driving power reference value corresponding to the current actual wind speed of the evaporator fan*(100%+wind speed power blocking increment percentage).

10. An air conditioning defrost control system, characterized in that: It includes a calibration module, an effective wind speed judgment module, a driving power judgment module and a blocking type judgment module. The calibration module is used to define an evaporator fan driving power reference value and calibrate it. The effective wind speed judgment module is used to judge whether the current evaporator fan actual operating wind speed is ≥ the evaporator fan wind speed to judge whether the effective value is established. If not, the conventional defrosting method is used to judge whether to enter defrosting. If yes, the evaporator fan driving power reference value corresponding to the current evaporator fan wind speed is extracted, and the wind speed blocking power value under the current evaporator fan wind speed condition is calculated. The driving power judgment module is used to sample and calculate the actual driving power of the evaporator fan under the heating mode, and judge whether the actual driving power of the evaporator fan is ≥ the wind speed blocking power value and lasts for more than T0 time. If not, it is judged as a frost-free state. If yes, it enters the evaporator fan power triggered defrost mode. The blocking type judgment module is used to judge whether the type of evaporator fan blockage is frost blockage or dirty blockage according to the defrosting situation of the evaporator fan power triggered defrost mode.

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