Defrost control method and device for determining when the refrigerator fin evaporator is full of frost

Abstract

This invention provides a defrosting control method and apparatus for determining when a refrigerator finned evaporator is fully frosted. The method involves collecting ambient temperature, average return pipe temperature, number of door openings and closings, and cumulative compressor running time to generate an initial defrosting control strategy. It obtains the return pipe temperature under refrigerator load and the refrigerator start-up temperature based on the ambient temperature. The method calculates the return pipe temperature difference based on the average return pipe temperature and the return pipe temperature. If the return pipe temperature difference is greater than or equal to a first preset temperature value, the initial defrosting control strategy is executed. If the return pipe temperature difference is less than the first preset temperature value but greater than or equal to a second preset temperature value, a first defrosting control strategy is executed. If the return pipe temperature difference is less than the second preset temperature value, the refrigerator sensor temperature is collected in real-time by a refrigerator sensor temperature acquisition module to calculate the refrigerator temperature difference. The method then determines whether to execute a second defrosting control strategy based on the refrigerator temperature difference, thus solving the problem of inaccurate determination of when the refrigerator finned evaporator is fully frosted.

Description

Technical Field

[0001] This application relates to the field of single-system air-cooled refrigerator technology, and in particular to a defrosting control method and device for determining when the refrigerator fin evaporator is full of frost. Background Technology

[0002] A single-system air-cooled refrigerator uses a cooling fan to carry cold air from the finned evaporator cavity (usually located in the freezer compartment) into different compartments for heat exchange, thus cooling each compartment. During the air circulation process, moisture from each compartment is also carried back to the finned evaporator and condenses into frost. When the frost layer becomes thick, the cooling effect deteriorates, requiring a defrosting heater to remove the frost from the finned evaporator.

[0003] To improve cooling efficiency, the frost condition of the refrigerator evaporator can be determined based on factors such as ambient temperature, cumulative compressor running time, and number of door openings and closings, in order to generate a defrosting control strategy. However, relying solely on these factors only provides a vague assessment of the frost condition of the refrigerator evaporator, and during operation, phenomena may occur where the evaporator is already fully frosted even though the preset defrosting conditions have not been met. Summary of the Invention

[0004] This application provides a defrosting control method and device for determining whether a refrigerator finned evaporator is fully frosted, in order to solve the problem of inaccurate determination of whether a refrigerator finned evaporator is fully frosted.

[0005] The first aspect of this application provides a defrosting control method for determining whether a refrigerator finned evaporator is fully frosted, the method comprising:

[0006] The ambient temperature, average return pipe temperature, number of door openings and closings, and cumulative compressor running time are collected through the ambient temperature acquisition module, return pipe temperature acquisition module, switch quantity acquisition module, and compressor operating parameter acquisition module.

[0007] An initial defrost control strategy is generated based on the ambient temperature, number of door openings and closings, and cumulative compressor running time.

[0008] The return air temperature and the refrigeration start-up temperature of the refrigerator under load are obtained based on the ambient temperature.

[0009] Calculate the return gas temperature difference based on the average temperature of the return gas pipe and the return gas temperature;

[0010] If the return air temperature difference is greater than or equal to the first preset temperature value, the initial defrost control strategy is executed.

[0011] If the return air temperature difference is less than the first preset temperature value and greater than or equal to the second preset temperature value, the first defrosting control strategy is executed.

[0012] If the return air temperature difference is less than the second preset temperature value, the refrigeration sensor temperature is collected in real time by the refrigeration sensor temperature acquisition module.

[0013] The refrigeration temperature difference is calculated based on the refrigeration sensor temperature and the refrigeration start-up temperature, and the second defrosting control strategy is executed based on the refrigeration temperature difference.

[0014] The above method not only considers factors such as ambient temperature, number of door openings and closings, and cumulative compressor running time, but also comprehensively considers the changes in the return gas temperature difference and the refrigeration temperature difference under the compressor's frosting state. It can more effectively determine whether the finned evaporator is fully frosted, reduce the risk of abnormal temperature rise in the non-freezing compartment or food spoilage, and solve the problem of inaccurate judgment of whether the refrigerator finned evaporator is fully frosted.

[0015] Optionally, the initialization frost control strategy includes:

[0016] Determine whether the initial defrosting conditions are met based on the ambient temperature, number of door openings and closings, and cumulative compressor running time.

[0017] If the initial defrosting conditions are met, control the compressor to stop and control the heater to turn on to heat the finned evaporator;

[0018] The temperature of the finned evaporator is obtained through a defrosting sensor;

[0019] When the temperature of the finned evaporator reaches the preset evaporator temperature, the heater is controlled to shut off.

[0020] When the heater has been off for a preset dripping waiting time, the compressor is restarted.

[0021] The temperature of the finned evaporator is obtained by a defrosting sensor. When the temperature reaches the preset value, the heater is turned off to prevent the evaporator from overheating and protect the equipment. After the heater is turned off, a preset dripping waiting time is used to ensure that the frost on the finned evaporator is completely melted, so as to avoid residual frost affecting the heating effect.

[0022] Optionally, the step of obtaining the average temperature of the return gas pipe through the return gas pipe temperature acquisition module includes:

[0023] When the compressor starts up at the preset compressor start time, the return pipe temperature is collected in real time by the return pipe temperature acquisition module.

[0024] Calculate the average return pipe temperature for each preset compressor time period to obtain the average return pipe temperature.

[0025] The average temperature of the return pipe and the average temperature of the ambient temperature can effectively reduce the impact of single measurement errors on the overall results, making the calculated average temperature more accurate and reliable. This helps to develop a more reasonable defrosting control strategy, thereby further improving operating efficiency and energy saving.

[0026] Optionally, the first defrosting control strategy includes:

[0027] If the return gas temperature difference is less than the first preset temperature value and greater than or equal to the second preset temperature value, the average temperature of the return gas pipe during the next three preset compressor time periods is obtained to calculate the return gas temperature difference for the next three periods.

[0028] If any return air temperature difference is greater than or equal to the first preset temperature value, the initial defrost control strategy is executed.

[0029] If the temperature difference between any two return air cycles is less than the first preset temperature value and greater than or equal to the second preset temperature value, the total defrosting interval in the initial defrosting control strategy will be reduced by 5 hours.

[0030] If the temperature difference between any two return gas cycles is less than the second preset temperature value, the average temperature of the return gas pipe during the next three preset compressor time periods will be obtained to calculate the temperature difference between the next three return gas cycles.

[0031] If the temperature difference between any two return gas temperatures is greater than or equal to the second preset temperature value, the judgment is re-evaluated based on the temperature difference of the last return gas.

[0032] If the temperature difference between any two return air temperatures is less than the second preset temperature value, the refrigeration sensor temperature is collected in real time by the refrigeration sensor temperature acquisition module.

[0033] The refrigeration temperature difference is calculated based on the refrigeration sensor temperature and the refrigeration start-up temperature, and the second defrosting control strategy is executed based on the refrigeration temperature difference.

[0034] By conducting a detailed analysis and judgment of the return gas temperature difference, and combining the judgment results to determine whether to conduct more data collection and judgment, it is possible to more accurately determine when defrosting is needed and how to perform the defrosting operation.

[0035] Optionally, before acquiring the refrigeration sensor temperature in real time via the refrigeration sensor temperature acquisition module, the method further includes:

[0036] If the return gas temperature difference is less than the second preset temperature value, continue to obtain the average temperature of the return gas pipe for the next three preset compressor time periods to calculate the return gas temperature difference for the next three periods.

[0037] If the temperature difference between any two return gas temperatures is greater than or equal to the second preset temperature value, the judgment is re-evaluated based on the temperature difference of the last return gas.

[0038] If the temperature difference between any two return air temperature values ​​is less than the second preset temperature value, the refrigeration sensor temperature is collected in real time by the refrigeration sensor temperature acquisition module.

[0039] Optionally, the second defrosting control strategy includes:

[0040] The refrigeration temperature difference is calculated based on the refrigeration sensor temperature and the refrigeration start-up temperature.

[0041] If the temperature difference is greater than or equal to the first preset temperature and the duration is greater than the first preset time, then the finned evaporator is determined to be fully frosted.

[0042] If the temperature difference in the refrigeration system is less than the first preset refrigeration temperature and greater than the second preset refrigeration temperature, and the duration is greater than or equal to the second preset time, the refrigeration auxiliary air damper is controlled to close.

[0043] When the refrigeration auxiliary air damper is closed for a third preset time, the refrigeration temperature difference is recalculated based on the refrigeration sensor temperature and the refrigeration start-up temperature.

[0044] If the recalculated refrigeration temperature difference is greater than or equal to the first preset refrigeration temperature, then the finned evaporator is determined to be fully frosted.

[0045] If the recalculated refrigeration temperature difference is less than the first preset refrigeration temperature but greater than the second preset refrigeration temperature, obtain the duration for which the refrigeration temperature difference is greater than the second preset refrigeration temperature.

[0046] If the temperature difference is greater than the second preset temperature for a duration of 3 hours or more, the finned evaporator is judged to be fully frosted.

[0047] If the duration for which the refrigeration temperature difference is greater than the second preset refrigeration temperature is less than 3 hours, continue to obtain the duration for which the refrigeration temperature difference is greater than the second preset refrigeration temperature.

[0048] Based on the temperature changes in the return air pipe, the system controls the refrigeration auxiliary air damper switch at the bottom air outlet of the refrigeration air duct. This, combined with the temperature changes from the refrigeration sensor, allows for real-time monitoring of the actual refrigeration environment and dynamic adjustment of the defrosting control strategy. Furthermore, it enables more precise determination of whether the finned evaporator is fully frosted, thus deciding whether defrosting is necessary. This helps reduce unnecessary energy consumption and equipment wear, improving the refrigerator's efficiency and lifespan.

[0049] Optionally, the second defrosting control strategy further includes:

[0050] If the recalculated refrigeration temperature difference is greater than the third preset refrigeration temperature and less than or equal to the second preset refrigeration temperature, continue to obtain the refrigeration temperature difference and duration.

[0051] If the time difference between the refrigeration temperatures within the fourth preset time period is less than the third preset refrigeration temperature is greater than or equal to 10 minutes, then the initial frost control strategy is executed.

[0052] If, after the fourth preset time, the refrigeration temperature difference is less than or equal to the second preset refrigeration temperature and greater than the third preset refrigeration temperature, continue to obtain the refrigeration temperature difference and duration.

[0053] If, after the fourth preset time, the refrigeration temperature difference is less than the first preset refrigeration temperature but greater than the second preset refrigeration temperature, the refrigeration temperature difference is recalculated based on the refrigeration sensor temperature and the refrigeration start-up temperature.

[0054] If, after the fourth preset time, the temperature difference in the refrigeration unit is greater than or equal to the first preset refrigeration unit, then the finned evaporator is determined to be fully frosted.

[0055] By continuously monitoring the refrigeration sensor temperature and the refrigeration start-up temperature, and calculating the refrigeration temperature difference, the actual condition of the refrigeration environment can be understood in real time, and the defrosting control strategy can be dynamically adjusted based on this data. By setting multiple preset refrigeration temperature thresholds and corresponding time conditions, it is possible to more accurately determine whether the finned evaporator is fully frosted, thereby deciding whether defrosting is necessary.

[0056] The second aspect of this application provides a defrosting control device for determining whether a refrigerator finned evaporator is fully frosted, applicable to the defrosting control method for determining whether a refrigerator finned evaporator is fully frosted as described in the first aspect. The device includes: a control unit, an ambient temperature acquisition module, a return pipe temperature acquisition module, a refrigerator sensor temperature acquisition module, a switch quantity acquisition module, and a compressor operating parameter acquisition module. The control unit is electrically connected to the ambient temperature acquisition module, the return pipe temperature acquisition module, the refrigerator sensor temperature acquisition module, the switch quantity acquisition module, and the compressor operating parameter acquisition module, respectively. The control unit is configured to:

[0057] The ambient temperature, average return pipe temperature, number of door openings and closings, and cumulative compressor operating time are obtained through the ambient temperature acquisition module, return pipe temperature acquisition module, switch quantity acquisition module, and compressor operating parameter acquisition module.

[0058] An initial defrost control strategy is generated based on the ambient temperature, number of door openings and closings, and cumulative compressor running time.

[0059] The return air temperature and the refrigeration start-up temperature of the refrigerator under load are obtained based on the ambient temperature.

[0060] Calculate the return gas temperature difference based on the average temperature of the return gas pipe and the return gas temperature;

[0061] If the return air temperature difference is greater than or equal to the first preset temperature value, the initial defrost control strategy is executed.

[0062] If the return air temperature difference is less than the first preset temperature value and greater than or equal to the second preset temperature value, the first defrosting control strategy is executed.

[0063] If the return air temperature difference is less than the second preset temperature value, the refrigeration sensor temperature is collected in real time by the refrigeration sensor temperature acquisition module.

[0064] The refrigeration temperature difference is calculated based on the refrigeration sensor temperature and the refrigeration start-up temperature, and the second defrosting control strategy is executed based on the refrigeration temperature difference.

[0065] The device not only considers factors such as ambient temperature, number of door openings and closings, and cumulative compressor running time, but also comprehensively considers the changes in the return gas temperature difference and the refrigeration temperature difference under the compressor's frosting state. It can more effectively determine whether the finned evaporator is fully frosted, reduce the risk of abnormal temperature rise in the non-freezing compartment or food spoilage, and solve the problem of inaccurate judgment of whether the refrigerator's finned evaporator is fully frosted.

[0066] Optionally, the device further includes a defrost sensor disposed on the surface of the finned evaporator, and the control unit is electrically connected to the defrost sensor to collect the temperature of the finned evaporator in real time; the initial defrost control strategy includes:

[0067] Determine whether the initial defrosting conditions are met based on the ambient temperature, number of door openings and closings, and cumulative compressor running time.

[0068] If the initial defrosting conditions are met, control the compressor to stop and control the heater to turn on to heat the finned evaporator;

[0069] The temperature of the finned evaporator is obtained through a defrosting sensor;

[0070] When the temperature of the finned evaporator reaches the preset evaporator temperature, the heater is controlled to shut off.

[0071] When the heater has been off for a preset dripping waiting time, the compressor is restarted.

[0072] The temperature of the finned evaporator is obtained by a defrosting sensor. When the temperature reaches the preset value, the heater is turned off to prevent the evaporator from overheating and protect the equipment. After the heater is turned off, a preset dripping waiting time is used to ensure that the frost on the finned evaporator is completely melted, so as to avoid residual frost affecting the heating effect.

[0073] Optionally, the device further includes a refrigerator auxiliary air damper, which is disposed on the air outlet path at the bottom of the refrigerator's air duct; the control unit is electrically connected to the refrigerator auxiliary air damper; the control unit is further configured to:

[0074] The refrigeration temperature difference is calculated based on the refrigeration sensor temperature and the refrigeration start-up temperature.

[0075] If the temperature difference is greater than or equal to the first preset temperature and the duration is greater than the first preset time, then the finned evaporator is determined to be fully frosted.

[0076] If the temperature difference in the refrigeration system is less than the first preset refrigeration temperature and greater than the second preset refrigeration temperature, and the duration is greater than or equal to the second preset time, the refrigeration auxiliary air damper is controlled to close.

[0077] When the refrigeration auxiliary air damper is closed for a third preset time, the refrigeration temperature difference is recalculated based on the refrigeration sensor temperature and the refrigeration start-up temperature.

[0078] If the recalculated refrigeration temperature difference is greater than or equal to the first preset refrigeration temperature, then the finned evaporator is determined to be fully frosted.

[0079] If the recalculated refrigeration temperature difference is less than the first preset refrigeration temperature but greater than the second preset refrigeration temperature, obtain the duration for which the refrigeration temperature difference is greater than the second preset refrigeration temperature.

[0080] If the temperature difference is greater than the second preset temperature for a duration of 3 hours or more, the finned evaporator is judged to be fully frosted.

[0081] If the duration for which the refrigeration temperature difference is greater than the second preset refrigeration temperature is less than 3 hours, continue to obtain the duration for which the refrigeration temperature difference is greater than the second preset refrigeration temperature.

[0082] Based on the temperature changes in the return air pipe, the system controls the refrigeration auxiliary air damper switch at the bottom air outlet of the refrigeration air duct. This, combined with the temperature changes from the refrigeration sensor, allows for real-time monitoring of the actual refrigeration environment and dynamic adjustment of the defrosting control strategy. Furthermore, it enables more precise determination of whether the finned evaporator is fully frosted, thus deciding whether defrosting is necessary. This helps reduce unnecessary energy consumption and equipment wear, improving the refrigerator's efficiency and lifespan.

[0083] As can be seen from the above technical solutions, this application provides a defrosting control method and device for determining when a refrigerator finned evaporator is fully frosted. It collects ambient temperature, average return pipe temperature, number of door openings and closings, and cumulative compressor running time through an ambient temperature acquisition module, a return pipe temperature acquisition module, a switch quantity acquisition module, and a compressor operating parameter acquisition module. Based on the ambient temperature, number of door openings and closings, and cumulative compressor running time, it generates an initial defrosting control strategy. Based on the ambient temperature, it obtains the return pipe temperature and the refrigerator start-up temperature when the refrigerator is under load. It calculates the return pipe temperature difference based on the average return pipe temperature and the return pipe temperature. If the return air temperature difference is greater than or equal to the first preset temperature value, the initial defrost control strategy is executed; if the return air temperature difference is less than the first preset temperature value but greater than or equal to the second preset temperature value, the first defrost control strategy is executed; if the return air temperature difference is less than the second preset temperature value, the refrigerator sensor temperature is collected in real time through the refrigerator sensor temperature acquisition module; the refrigerator temperature difference is calculated based on the refrigerator sensor temperature and the refrigerator start-up temperature, so as to determine whether to execute the second defrost control strategy based on the refrigerator temperature difference, in order to solve the problem of inaccurate judgment of the refrigerator fin evaporator being full of frost. Attached Figure Description

[0084] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0085] Figure 1 A flowchart illustrating the defrosting control method for determining when a refrigerator finned evaporator is fully frosted, as provided in an embodiment of this application.

[0086] Figure 2 A flowchart illustrating the first defrosting control strategy in the defrosting control method for determining when the refrigerator finned evaporator is full of frost, as provided in the embodiments of this application;

[0087] Figure 3 This is a flowchart illustrating the second defrosting control strategy in the defrosting control method for determining when the refrigerator fin evaporator is full of frost, as provided in the embodiments of this application. Detailed Implementation

[0088] The embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described below do not represent all embodiments consistent with this application. They are merely examples of systems and methods consistent with some aspects of this application.

[0089] A single-system air-cooled refrigerator uses a cooling fan to carry cold air from the finned evaporator cavity (usually located in the freezer compartment) into different compartments for heat exchange, thus cooling each compartment. During the air circulation process, moisture from each compartment is also carried back to the finned evaporator and condenses into frost. When the frost layer becomes thick, the cooling effect deteriorates, requiring a defrosting heater to remove the frost from the finned evaporator.

[0090] To improve cooling efficiency, the frost condition of the refrigerator evaporator can be determined based on factors such as ambient temperature, cumulative compressor running time, and number of door openings and closings, in order to generate a defrosting control strategy. However, relying solely on these factors only provides a vague assessment of the frost condition of the refrigerator evaporator, and during operation, phenomena may occur where the evaporator is already fully frosted even though the preset defrosting conditions have not been met.

[0091] To address the problem of inaccurate judgment of a refrigerator finned evaporator being fully frosted, some embodiments of this application provide a defrosting control method for judging whether a refrigerator finned evaporator is fully frosted, applicable to a defrosting control device for judging whether a refrigerator finned evaporator is fully frosted. See [link to relevant documentation]. Figure 1 The method includes:

[0092] S100: Collects the average ambient temperature Th, average return pipe temperature Tc, number of door openings and closings, and cumulative compressor running time through the ambient temperature acquisition module, return pipe temperature acquisition module, switch quantity acquisition module, and compressor operating parameter acquisition module.

[0093] It should be understood that the ambient temperature acquisition module can be used to acquire ambient temperature; the return gas pipe temperature acquisition module can be used to acquire return gas pipe temperature; the switch quantity acquisition module can be used to acquire the number of times the door is opened and closed; and the compressor operating parameter acquisition module can be used to acquire the cumulative operating time of the compressor.

[0094] In some embodiments, the step of obtaining the average temperature Tc of the return pipe through the return pipe temperature acquisition module includes:

[0095] When the compressor starts up at the preset compressor start time t1, the return pipe temperature is collected in real time by the return pipe temperature acquisition module.

[0096] Calculate the average return pipe temperature for each preset compressor time period t2, and use it as the average return pipe temperature Tc.

[0097] It should be understood that the preset compressor start-up time t1 can be selected from 10 to 30 minutes to allow the compressor to start up and run stably. The preset compressor time period t2 can be selected from 10 to 20 minutes. Similarly, the average ambient temperature collected within the preset compressor time period t2 can be used as the average ambient temperature Th.

[0098] The average temperature of the return pipe and the average temperature of the ambient temperature can effectively reduce the impact of single measurement errors on the overall results, making the calculated average temperature more accurate and reliable. This helps to develop a more reasonable defrosting control strategy, thereby further improving operating efficiency and energy saving.

[0099] S200: Generate an initial defrost control strategy based on the average ambient temperature Th, the number of door openings and closings, and the cumulative compressor running time.

[0100] In some embodiments, the initialization frost control strategy includes:

[0101] The initial defrosting conditions are determined based on the average ambient temperature (Th), the number of times the door is opened and closed, and the cumulative running time of the compressor.

[0102] It should be understood that, in addition to the average ambient temperature Th, the number of times the door is opened and closed, and the cumulative running time of the compressor, other factors can be used to determine whether the initial defrosting conditions are met.

[0103] If the initial frost conditions are met, the compressor is stopped and the heater is turned on to heat the finned evaporator.

[0104] The temperature of the finned evaporator is obtained through a defrosting sensor.

[0105] When the temperature of the finned evaporator reaches the preset evaporator temperature, the heater is controlled to shut off.

[0106] When the heater has been off for a preset dripping waiting time, the compressor is restarted.

[0107] It should be understood that the preset evaporator temperature and preset dripping time can be determined through experiments and tests.

[0108] The temperature of the finned evaporator is obtained by a defrosting sensor. When the temperature reaches the preset value, the heater is turned off to prevent the evaporator from overheating and protect the equipment. After the heater is turned off, a preset dripping waiting time is used to ensure that the frost on the finned evaporator is completely melted, so as to avoid residual frost affecting the heating effect.

[0109] S300: Obtain the return air temperature Tc' and the refrigeration start-up temperature Trk of the refrigerator under load based on the average ambient temperature Th.

[0110] It should be understood that the return gas temperature Tc' can be obtained by looking up the average value of the ambient temperature Th during this stage. See the table below for details:

[0111]

[0112] The refrigeration unit's start-up temperature (Trk) can also be calculated based on the average ambient temperature. The calculation formula is as follows:

[0113] Trk=Th-10℃.

[0114] S400: Calculate the return gas temperature difference, i.e., Tc-Tc', based on the average temperature Tc of the return gas pipe and the return gas temperature Tc'.

[0115] S500: If the return air temperature difference is greater than or equal to the first preset temperature value N1, execute the initial frost control strategy.

[0116] S600: If the return air temperature difference is less than the first preset temperature value N1 and greater than or equal to the second preset temperature value N2, execute the first defrosting control strategy.

[0117] In some embodiments, see Figure 2 The first defrosting control strategy includes:

[0118] S610: If the return gas temperature difference is less than the first preset temperature value N1 and greater than or equal to the second preset temperature value N2, continue to obtain the average temperature Tc of the return gas pipe for the next three preset compressor time periods t2, so as to calculate the return gas temperature difference for the next three times.

[0119] S620: If any return air temperature difference is greater than or equal to the first preset temperature value N1, execute the initial frost control strategy.

[0120] S630: If the temperature difference between any two return air cycles is less than the first preset temperature value N1 and greater than or equal to the second preset temperature value N2, the total defrosting interval in the initial defrosting control strategy will be reduced by 5 hours.

[0121] S640: If the temperature difference between any two return gas cycles is less than the second preset temperature value N2, then continue to obtain the average temperature Tc of the return gas pipe for the next three preset compressor time periods to calculate the temperature difference between the next three return gas cycles.

[0122] S641: If the temperature difference between any two return gas temperatures is greater than or equal to the second preset temperature value N2, re-determine based on the temperature difference of the last return gas.

[0123] It should be understood that the range of the first preset temperature value N1 and the second preset temperature value N2 is: -1≤N1≤0.5; -2≤N2≤0; and N2<N1. If the temperature difference between any two return air temperature values ​​is less than the second preset temperature value N2, then proceed to step S700.

[0124] By conducting a detailed analysis and judgment of the return gas temperature difference, and combining the judgment results to determine whether to conduct more data collection and judgment, it is possible to more accurately determine when defrosting is needed and how to perform the defrosting operation.

[0125] S700: If the return air temperature difference is less than the second preset temperature value N2, the refrigeration sensor temperature Tr is collected in real time by the refrigeration sensor temperature acquisition module.

[0126] In some embodiments, before the refrigeration sensor temperature Tr is acquired in real time by the refrigeration sensor temperature acquisition module, the method further includes:

[0127] If the return gas temperature difference is less than the second preset temperature value N2, the average temperature Tc of the return gas pipe during the next three preset compressor time periods is obtained to calculate the return gas temperature difference for the next three periods.

[0128] If the temperature difference between any two return gas temperature values ​​is greater than or equal to the second preset temperature value N2, the judgment is recalculated based on the temperature difference of the last return gas temperature.

[0129] If the temperature difference between any two return air temperature values ​​is less than the second preset temperature value N2, the refrigeration sensor temperature Tr is collected in real time by the refrigeration sensor temperature acquisition module.

[0130] S800: Calculate the refrigeration temperature difference ΔT based on the refrigeration sensor temperature Tr and the refrigeration start-up temperature Trk, and determine whether to execute the second defrosting control strategy based on the refrigeration temperature difference ΔT.

[0131] The above method not only considers factors such as ambient temperature, number of door openings and closings, and cumulative compressor running time, but also comprehensively considers the changes in the return gas temperature difference and the refrigeration temperature difference under the compressor's frosting state. It can more effectively determine whether the finned evaporator is fully frosted, reduce the risk of abnormal temperature rise in the non-freezing compartment or food spoilage, and solve the problem of inaccurate judgment of whether the refrigerator finned evaporator is fully frosted.

[0132] In some embodiments, see Figure 3 The second defrosting control strategy includes:

[0133] S810: Calculate the refrigeration temperature difference ΔT based on the refrigeration sensor temperature Tr and the refrigeration start-up temperature Trk.

[0134] It should be understood that ΔT = Tr - Trk.

[0135] S820: If the refrigeration temperature difference ΔT is greater than or equal to the first preset refrigeration temperature n1, and the duration is greater than the first preset time t1, then the finned evaporator is determined to be full of frost.

[0136] It should be understood that the range of the first preset refrigeration temperature is: 1 ≤ n1 ≤ 5. The first preset time can be determined based on experimental data, such as 10 minutes.

[0137] S830: If the refrigeration temperature difference ΔT is less than the first preset refrigeration temperature n1 and greater than the second preset refrigeration temperature n2, and the duration is greater than or equal to the second preset time t2, control the refrigeration auxiliary air damper to close.

[0138] It should be understood that the range of the second preset refrigeration temperature is: 0 ≤ n2 ≤ 3, and n2 < n1. The second preset time can be determined based on experimental data, such as 10 minutes.

[0139] S840: When the refrigeration auxiliary air damper is closed for a third preset time t3, the refrigeration temperature difference ΔT is recalculated based on the refrigeration sensor temperature Tr and the refrigeration start-up temperature Trk.

[0140] It should be understood that the third preset time t3 is 30 minutes.

[0141] S850: If the recalculated refrigeration temperature difference ΔT is greater than or equal to the first preset refrigeration temperature n1, then the finned evaporator is determined to be full of frost.

[0142] S860: If the recalculated refrigeration temperature difference ΔT is less than the first preset refrigeration temperature n1 and greater than the second preset refrigeration temperature n2, obtain the duration for which the refrigeration temperature difference ΔT is greater than the second preset refrigeration temperature n2.

[0143] S861: If the duration of the refrigeration temperature difference ΔT being greater than the second preset refrigeration temperature n2 is greater than or equal to 3 hours, then the finned evaporator is judged to be full of frost.

[0144] S862: If the duration for which the refrigeration temperature difference ΔT is greater than the second preset refrigeration temperature n2 is less than 3 hours, the duration for which the refrigeration temperature difference ΔT is greater than the second preset refrigeration temperature n2 is determined.

[0145] It should be understood that once the finned evaporator is fully frosted, the compressor will be restarted after 6 hours, and the compressor will be stopped immediately while the heater is turned on to heat the finned evaporator.

[0146] Based on the temperature changes in the return air pipe, the system controls the refrigeration auxiliary air damper switch at the bottom air outlet of the refrigeration air duct. This, combined with the temperature changes from the refrigeration sensor, allows for real-time monitoring of the actual refrigeration environment and dynamic adjustment of the defrosting control strategy. Furthermore, it enables more precise determination of whether the finned evaporator is fully frosted, thus deciding whether defrosting is necessary. This helps reduce unnecessary energy consumption and equipment wear, improving the refrigerator's efficiency and lifespan.

[0147] In some embodiments, the second defrosting control strategy further includes:

[0148] If the recalculated refrigeration temperature difference ΔT is greater than the third preset refrigeration temperature n3 and less than or equal to the second preset refrigeration temperature n2, continue to obtain the refrigeration temperature difference ΔT and the duration.

[0149] If the refrigeration temperature difference ΔT within the fourth preset time period is less than the third preset refrigeration temperature n3 for a period of 10 minutes or more, then the initial frost control strategy is executed.

[0150] If, after the fourth preset time, the refrigeration temperature difference ΔT is less than or equal to the second preset refrigeration temperature n2 and greater than the third preset refrigeration temperature n3, the refrigeration temperature difference ΔT and the duration are continuously obtained.

[0151] If, after the fourth preset time, the refrigeration temperature difference ΔT is less than the first preset refrigeration temperature n1 and greater than the second preset refrigeration temperature n2, the refrigeration temperature difference ΔT is recalculated based on the refrigeration sensor temperature Tr and the refrigeration start-up temperature Trk.

[0152] If, after the fourth preset time, the temperature difference ΔT is greater than or equal to the first preset temperature n1, then the finned evaporator is determined to be fully frosted.

[0153] It should be understood that the range of the third preset refrigeration temperature is: -1 ≤ n3 ≤ 1, and n3 < n2 < n1. The fourth preset time can be determined based on experimental data, such as 5 minutes. Furthermore, if the recalculated refrigeration temperature difference ΔT is less than or equal to the third preset refrigeration temperature n3, the initial frost control strategy is executed.

[0154] By continuously monitoring the refrigeration sensor temperature and the refrigeration start-up temperature, and calculating the refrigeration temperature difference, the actual condition of the refrigeration environment can be understood in real time, and the defrosting control strategy can be dynamically adjusted based on this data. By setting multiple preset refrigeration temperature thresholds and corresponding time conditions, it is possible to more accurately determine whether the finned evaporator is fully frosted, thereby deciding whether defrosting is necessary.

[0155] It should be understood that a single-system frost-free refrigerator includes a compressor, condenser, fan, capillary tube or expansion valve, dryer filter, defrosting device, and control unit. The compressor is one of the core components of a frost-free refrigerator, responsible for compressing the refrigerant into a high-temperature, high-pressure gas, providing power for the refrigeration cycle. The finned evaporator is located inside the refrigerator. When the refrigerant evaporates in the finned evaporator, it absorbs heat from the surrounding air, lowering the surface temperature of the finned evaporator and thus cooling the interior of the refrigerator. The condenser cools and condenses the high-temperature, high-pressure refrigerant gas output from the compressor into a liquid. In the condenser, the refrigerant releases heat, which is dissipated to the outside through the surrounding air or heat sink. Fans are divided into internal and external fans. Internal fans mainly force air circulation inside the refrigerator, ensuring that cold air is evenly distributed throughout, improving cooling efficiency; external fans accelerate the heat dissipation of the condenser, improving cooling efficiency. The capillary tube or expansion valve connects the condenser and the finned evaporator, controlling the flow and pressure of the refrigerant. It can regulate the evaporation rate and amount of refrigerant in the finned evaporator, thereby controlling the cooling capacity. A dryer filter is installed between the condenser and the capillary tube to filter impurities and moisture from the refrigerant, preventing them from entering the capillary tube and finned evaporator and causing blockages and ice buildup. The defrosting device melts frost into water using a heater, and then drains the water from the refrigerator through a drainage system.

[0156] This application also provides a defrosting control device for determining whether a refrigerator finned evaporator is full of frost, which is applicable to the defrosting control method for determining whether a refrigerator finned evaporator is full of frost as described in the above embodiments. The device includes: a control unit, an ambient temperature acquisition module, a return gas pipe temperature acquisition module, a refrigerator sensor temperature acquisition module, a switch quantity acquisition module, and a compressor operating parameter acquisition module; the control unit is electrically connected to the ambient temperature acquisition module, the return gas pipe temperature acquisition module, the refrigerator sensor temperature acquisition module, the switch quantity acquisition module, and the compressor operating parameter acquisition module, respectively.

[0157] It should be understood that the control unit may be a microcontroller. The ambient temperature acquisition module may be installed on the surface of the refrigerator. The return gas pipe temperature acquisition module is installed on the return gas pipe inside the refrigerator. The refrigerator sensor temperature acquisition module is installed on the refrigerator sensor. The switch quantity acquisition module is installed near the refrigerator door. The compressor operating parameter acquisition module is electrically connected to the compressor and can acquire the compressor switching time.

[0158] The control unit is configured to:

[0159] The average ambient temperature Th, average return pipe temperature Tc, number of door openings and closings, and cumulative compressor running time are obtained through the ambient temperature acquisition module, return pipe temperature acquisition module, switch quantity acquisition module, and compressor operating parameter acquisition module.

[0160] An initial defrost control strategy is generated based on the average ambient temperature Th, the number of door openings and closings, and the cumulative compressor running time.

[0161] The return air temperature Tc' and the refrigeration start-up temperature Trk of the refrigerator under load are obtained based on the average ambient temperature Th.

[0162] Calculate the return gas temperature difference based on the average temperature Tc of the return gas pipe and the return gas temperature Tc'.

[0163] If the return air temperature difference is greater than or equal to the first preset temperature value N1, the initial frost control strategy is executed.

[0164] If the return air temperature difference is less than the first preset temperature value N1 and greater than or equal to the second preset temperature value N2, the first defrosting control strategy is executed.

[0165] If the return air temperature difference is less than the second preset temperature value N2, the refrigeration sensor temperature Tr is collected in real time by the refrigeration sensor temperature acquisition module.

[0166] The refrigeration temperature difference ΔT is calculated based on the refrigeration sensor temperature Tr and the refrigeration start-up temperature Trk, and the second defrosting control strategy is determined based on the refrigeration temperature difference ΔT.

[0167] The device not only considers factors such as ambient temperature, number of door openings and closings, and cumulative compressor running time, but also comprehensively considers the changes in the return gas temperature difference and the refrigeration temperature difference under the compressor's frosting state. It can more effectively determine whether the finned evaporator is fully frosted, reduce the risk of abnormal temperature rise in the non-freezing compartment or food spoilage, and solve the problem of inaccurate judgment of whether the refrigerator's finned evaporator is fully frosted.

[0168] In some embodiments, the device further includes a defrost sensor disposed on the surface of the finned evaporator, and the control unit is electrically connected to the defrost sensor to collect the temperature of the finned evaporator in real time.

[0169] The initialization frost control strategy includes:

[0170] Determine whether the initial defrosting conditions are met based on the average ambient temperature Th, the number of door openings and closings, and the cumulative compressor running time.

[0171] If the initial defrosting conditions are met, control the compressor to stop and control the heater to turn on to heat the finned evaporator;

[0172] The temperature of the finned evaporator is obtained through a defrosting sensor;

[0173] When the temperature of the finned evaporator reaches the preset evaporator temperature, the heater is controlled to shut off.

[0174] When the heater has been off for a preset dripping waiting time, the compressor is restarted.

[0175] The temperature of the finned evaporator is obtained by a defrosting sensor. When the temperature reaches the preset value, the heater is turned off to prevent the evaporator from overheating and protect the equipment. After the heater is turned off, a preset dripping waiting time is used to ensure that the frost on the finned evaporator is completely melted, so as to avoid residual frost affecting the heating effect.

[0176] In some embodiments, the device further includes a refrigerator auxiliary air damper, which is disposed on the air outlet air path at the bottom of the refrigerator's refrigerator air duct; the control unit is electrically connected to the refrigerator auxiliary air damper.

[0177] It should be understood that for refrigerators with the refrigeration sensor located at the bottom of the refrigerator compartment, even if the top of the refrigerator compartment is too high due to frost on the evaporator fins, the air outlet at the bottom of the refrigerator compartment still has enough airflow to cool the refrigeration sensor, preventing it from accurately reflecting the compartment temperature. To address this situation, the auxiliary refrigeration damper needs to be installed in the air duct at the bottom of the refrigerator compartment.

[0178] The control unit is also configured to:

[0179] The refrigeration temperature difference ΔT is calculated based on the refrigeration sensor temperature Tr and the refrigeration start-up temperature Trk.

[0180] If the refrigeration temperature difference ΔT is greater than or equal to the first preset refrigeration temperature and the duration is greater than the first preset time, then the finned evaporator is determined to be fully frosted.

[0181] If the refrigeration temperature difference ΔT is less than the first preset refrigeration temperature and greater than the second preset refrigeration temperature, and the duration is greater than or equal to the second preset time, the refrigeration auxiliary air damper is controlled to close.

[0182] When the refrigeration auxiliary air damper is closed for a third preset time, the refrigeration temperature difference ΔT is recalculated based on the refrigeration sensor temperature Tr and the refrigeration start-up temperature Trk.

[0183] If the recalculated refrigeration temperature difference ΔT is greater than or equal to the first preset refrigeration temperature, then the finned evaporator is determined to be fully frosted.

[0184] If the recalculated refrigeration temperature difference ΔT is less than the first preset refrigeration temperature but greater than the second preset refrigeration temperature, obtain the duration for which the refrigeration temperature difference ΔT is greater than the second preset refrigeration temperature.

[0185] If the duration of the refrigeration temperature difference ΔT being greater than the second preset refrigeration temperature is greater than or equal to 3 hours, then the finned evaporator is judged to be fully frosted.

[0186] If the duration for which the refrigeration temperature difference ΔT is greater than the second preset refrigeration temperature is less than 3 hours, continue to obtain the duration for which the refrigeration temperature difference ΔT is greater than the second preset refrigeration temperature.

[0187] Based on the temperature changes in the return air pipe, the system controls the refrigeration auxiliary air damper switch at the bottom air outlet of the refrigeration air duct. This, combined with the temperature changes from the refrigeration sensor, allows for real-time monitoring of the actual refrigeration environment and dynamic adjustment of the defrosting control strategy. Furthermore, it enables more precise determination of whether the finned evaporator is fully frosted, thus deciding whether defrosting is necessary. This helps reduce unnecessary energy consumption and equipment wear, improving the refrigerator's efficiency and lifespan.

[0188] As can be seen from the above technical solutions, the embodiments of this application provide a defrosting control method and device for determining when the evaporator of a refrigerator finned evaporator is fully frosted. This method collects the average ambient temperature Th, the average return pipe temperature Tc, the number of door openings and closings, and the cumulative compressor running time through an ambient temperature acquisition module, a return pipe temperature acquisition module, a switch quantity acquisition module, and a compressor operating parameter acquisition module. An initial defrosting control strategy is generated based on the average ambient temperature Th, the number of door openings and closings, and the cumulative compressor running time. The return pipe temperature Tc' and the refrigeration start-up temperature Trk are obtained based on the average ambient temperature Th. A defrosting control strategy is calculated based on the average return pipe temperature Tc and the return pipe temperature Tc'. Calculate the return air temperature difference; if the return air temperature difference is greater than or equal to the first preset temperature value N1, execute the initial defrost control strategy; if the return air temperature difference is less than the first preset temperature value N1 but greater than or equal to the second preset temperature value N2, execute the first defrost control strategy; if the return air temperature difference is less than the second preset temperature value N2, collect the refrigerator sensor temperature Tr in real time through the refrigerator sensor temperature acquisition module; calculate the refrigerator temperature difference ΔT based on the refrigerator sensor temperature Tr and the refrigerator start-up temperature Trk, and determine whether to execute the second defrost control strategy based on the refrigerator temperature difference ΔT to solve the problem of inaccurate judgment of full frost on the refrigerator fin evaporator.

[0189] Similar parts between the embodiments provided in this application can be referred to mutually. The specific implementation methods provided above are only a few examples under the overall concept of this application and do not constitute a limitation on the scope of protection of this application. For those skilled in the art, any other implementation methods extended from the solution of this application without creative effort shall fall within the scope of protection of this application.

Claims

1. A defrosting control method for determining frost buildup on a fin evaporator of a refrigerator, characterized by, The method comprises: collecting the ambient temperature, the average temperature of the return air pipe, the number of door opening and closing, and the cumulative running time of the compressor through the ring temperature acquisition module, the return air pipe temperature acquisition module, the switch quantity acquisition module, and the compressor running parameter acquisition module; generating an initial defrosting control strategy according to the ambient temperature, the number of door opening and closing, and the cumulative running time of the compressor; obtaining the return air temperature and the refrigeration start point temperature at the time of the refrigerator load according to the ambient temperature; calculating the return air temperature difference value according to the average temperature of the return air pipe and the return air temperature; if the return air temperature difference value is greater than or equal to a first preset temperature value, executing the initial defrosting control strategy; if the return air temperature difference value is less than the first preset temperature value and greater than or equal to a second preset temperature value, executing a first defrosting control strategy; if the return air temperature difference value is less than the second preset temperature value, collecting the refrigeration sensor temperature in real time through the refrigeration sensor temperature acquisition module; calculating the refrigeration temperature difference value according to the refrigeration sensor temperature and the refrigeration start point temperature, and judging whether to execute a second defrosting control strategy according to the refrigeration temperature difference value; the initial defrosting control strategy comprises: judging whether the initial defrosting condition is met according to the ambient temperature, the number of door opening and closing, and the cumulative running time of the compressor; if the initial defrosting condition is met, stopping the compressor and turning on the heater to heat the fin evaporator; obtaining the fin evaporator temperature through the defrosting sensor; when the fin evaporator temperature reaches a preset evaporator temperature, turning off the heater; when the time of turning off the heater reaches a preset water dripping waiting time, re-controlling the compressor to be turned on; the first defrosting control strategy comprises: if the return air temperature difference value is less than the first preset temperature value and greater than or equal to the second preset temperature value, continuing to obtain the average temperature of the return air pipe in the subsequent three preset compressor time periods to calculate the subsequent three return air temperature difference values; if any one return air temperature difference value is greater than or equal to the first preset temperature value, executing the initial defrosting control strategy; if any two return air temperature difference values are less than the first preset temperature value and greater than or equal to the second preset temperature value, reducing the total defrosting interval time in the initial defrosting control strategy by 5 hours; if any two return air temperature difference values are less than the second preset temperature value, continuing to obtain the average temperature of the return air pipe in the subsequent three preset compressor time periods to calculate the subsequent three return air temperature difference values; if any two return air temperature difference values are greater than or equal to the second preset temperature value, re-judging according to the last return air temperature difference value; if any two return air temperature difference values are less than the second preset temperature value, collecting the refrigeration sensor temperature in real time through the refrigeration sensor temperature acquisition module; calculating the refrigeration temperature difference value according to the refrigeration sensor temperature and the refrigeration start point temperature, and judging whether to execute the second defrosting control strategy according to the refrigeration temperature difference value; the second defrosting control strategy comprises: calculating the refrigeration temperature difference value according to the refrigeration sensor temperature and the refrigeration start point temperature; if the refrigeration temperature difference value is greater than or equal to a first preset refrigeration temperature and the duration is greater than a first preset time, it is judged that the fin evaporator is full of frost; If the refrigeration temperature difference is less than the first preset refrigeration temperature and greater than the second preset refrigeration temperature, and the duration is greater than or equal to the second preset time, the refrigeration auxiliary damper is controlled to be closed; When the time for which the refrigeration auxiliary damper is closed reaches the third preset time, the refrigeration temperature difference is recalculated according to the refrigeration sensor temperature and the refrigeration startup point temperature; If the recalculated refrigeration temperature difference is greater than or equal to the first preset refrigeration temperature, it is determined that the finned evaporator is full of frost; If the recalculated refrigeration temperature difference is less than the first preset refrigeration temperature and greater than the second preset refrigeration temperature, the duration for which the refrigeration temperature difference is greater than the second preset refrigeration temperature is obtained; If the duration for which the refrigeration temperature difference is greater than the second preset refrigeration temperature is greater than or equal to 3 hours, it is determined that the finned evaporator is full of frost; If the duration for which the refrigeration temperature difference is greater than the second preset refrigeration temperature is less than 3 hours, the duration for which the refrigeration temperature difference is greater than the second preset refrigeration temperature is continuously obtained.

2. The defrosting control method for determining frost buildup on a fin evaporator of a refrigerator according to claim 1, characterized in that, The step of obtaining the average temperature of the gas return pipe through the gas return pipe temperature acquisition module comprises: When the opening time of the compressor reaches the preset compressor startup time, the temperature of the gas return pipe is acquired in real time through the gas return pipe temperature acquisition module; The average value of the temperature of the gas return pipe in each preset compressor time period is calculated as the average temperature of the gas return pipe.

3. The defrosting control method of judging frost accumulation of a fin evaporator of a refrigerator according to claim 2, characterized by, Before the refrigeration sensor temperature is acquired in real time through the refrigeration sensor temperature acquisition module, the method further comprises: If the gas return temperature difference is less than the second preset temperature value, the average temperature of the gas return pipe in the subsequent three preset compressor time periods is continuously obtained to calculate the subsequent three gas return temperature differences; If any two gas return temperature differences are greater than or equal to the second preset temperature value, the last gas return temperature difference is used for re-determination; If any two gas return temperature differences are less than the second preset temperature value, the refrigeration sensor temperature is acquired in real time through the refrigeration sensor temperature acquisition module.

4. The defrosting control method of judging frost accumulation of a fin evaporator of a refrigerator according to claim 3, characterized by, The second defrosting control strategy further comprises: If the recalculated refrigeration temperature difference is greater than the third preset refrigeration temperature and less than or equal to the second preset refrigeration temperature, the refrigeration temperature difference and the duration are continuously obtained; If the time for which the refrigeration temperature difference is less than the third preset refrigeration temperature within the fourth preset time is greater than or equal to 10 minutes, the initial defrosting control strategy is executed; If, after the fourth preset time, the refrigeration temperature difference is less than or equal to the second preset refrigeration temperature and greater than the third preset refrigeration temperature, the refrigeration temperature difference and the duration are continuously obtained; If, after the fourth preset time, the refrigeration temperature difference is less than the first preset refrigeration temperature and greater than the second preset refrigeration temperature, the refrigeration temperature difference is recalculated according to the refrigeration sensor temperature and the refrigeration startup point temperature; If, after the fourth preset time, the refrigeration temperature difference is greater than or equal to the first preset refrigeration temperature, it is determined that the finned evaporator is full of frost.

5. A defrosting control device for determining the frosting of a fin evaporator of a refrigerator, characterized by, The device suitable for the defrosting control method for judging whether the fin evaporator of the refrigerator is full of frost according to any one of claims 1-4, the device comprising: a control unit, a ring temperature acquisition module, a return air pipe temperature acquisition module, a refrigeration sensor temperature acquisition module, a switch value acquisition module, and a compressor operating parameter acquisition module; the control unit is electrically connected with the ring temperature acquisition module, the return air pipe temperature acquisition module, the refrigeration sensor temperature acquisition module, the switch value acquisition module, and the compressor operating parameter acquisition module; the control unit is configured to: obtain the environmental temperature, the average return air pipe temperature, the number of door opening and closing, and the cumulative operating time of the compressor through the ring temperature acquisition module, the return air pipe temperature acquisition module, the switch value acquisition module, and the compressor operating parameter acquisition module; generate an initial frost control strategy according to the environmental temperature, the number of door opening and closing, and the cumulative operating time of the compressor; obtain the return air temperature and the refrigeration start temperature at the time of the load of the refrigerator according to the environmental temperature; calculate the return air temperature difference value according to the average return air pipe temperature and the return air temperature; if the return air temperature difference value is greater than or equal to a first preset temperature value, execute the initial frost control strategy; if the return air temperature difference value is less than the first preset temperature value and greater than or equal to a second preset temperature value, execute a first defrosting control strategy; if the return air temperature difference value is less than the second preset temperature value, acquire the refrigeration sensor temperature in real time through the refrigeration sensor temperature acquisition module; calculate the refrigeration temperature difference value according to the refrigeration sensor temperature and the refrigeration start temperature, and judge whether to execute a second defrosting control strategy according to the refrigeration temperature difference value.

6. The defrosting control apparatus for determining frost accumulation on a fin evaporator of a refrigerator according to claim 5, wherein further comprising a defrosting sensor, the defrosting sensor being arranged on the surface of the fin evaporator, and the control unit being electrically connected with the defrosting sensor to acquire the temperature of the fin evaporator in real time; the initial frost control strategy comprising: judging whether the initial frost condition is met according to the environmental temperature, the number of door opening and closing, and the cumulative operating time of the compressor; if the initial frost condition is met, stopping the compressor and turning on the heater to heat the fin evaporator; acquiring the temperature of the fin evaporator through the defrosting sensor; when the temperature of the fin evaporator reaches a preset evaporator temperature, turning off the heater; when the time of turning off the heater reaches a preset water dripping waiting time, turning on the compressor again.

7. The defrosting control device for determining the frost accumulation of a fin evaporator of a refrigerator according to claim 5, wherein further comprising a refrigeration auxiliary air door, the refrigeration auxiliary air door being arranged on the air outlet air path at the bottom of the refrigeration air duct of the refrigerator; the control unit is electrically connected with the refrigeration auxiliary air door; the control unit is further configured to: calculate the refrigeration temperature difference value according to the refrigeration sensor temperature and the refrigeration start temperature; if the refrigeration temperature difference value is greater than or equal to a first preset refrigeration temperature and the duration is greater than a first preset time, it is judged that the fin evaporator is full of frost; if the refrigeration temperature difference value is less than the first preset refrigeration temperature and greater than a second preset refrigeration temperature, and the duration is greater than or equal to a second preset time, control the refrigeration auxiliary air door to be closed; when the time for the refrigeration auxiliary damper to be closed reaches a third preset time, a refrigeration temperature difference is recalculated according to the refrigeration sensor temperature and the refrigeration start-up point temperature; if the refrigeration temperature difference recalculated is greater than or equal to a first preset refrigeration temperature, it is determined that the finned evaporator is full of frost; if the refrigeration temperature difference recalculated is less than the first preset refrigeration temperature and greater than a second preset refrigeration temperature, a duration for which the refrigeration temperature difference is greater than the second preset refrigeration temperature is obtained; if the duration for which the refrigeration temperature difference is greater than the second preset refrigeration temperature is greater than or equal to 3 hours, it is determined that the finned evaporator is full of frost; if the duration for which the refrigeration temperature difference is greater than the second preset refrigeration temperature is less than 3 hours, the duration for which the refrigeration temperature difference is greater than the second preset refrigeration temperature is continuously obtained.

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