Defrosting control method and device for judging full frost of refrigerator fin evaporator

Abstract

The invention provides a defrosting control method and device for judging full frost of a fin evaporator of a refrigerator. The defrosting control method comprises the steps that the environment temperature, the average temperature of an air return pipe, the door opening and closing frequency and the accumulated operation time of a compressor are collected to generate an initial frost control strategy; according to the environment temperature, the air return temperature and the refrigeration starting point temperature when the refrigerator is loaded are obtained; calculating a return air temperature difference value according to the return air pipe average temperature and the return air temperature; if the air return temperature difference value is larger than or equal to the first preset temperature value, an initial frost control strategy is executed; if the air return temperature difference value is smaller than the first preset temperature value and larger than or equal to the second preset temperature value, a first defrosting control strategy is executed; and if the return air temperature difference value is smaller than a second preset temperature value, the refrigeration sensor temperature is collected in real time through a refrigeration sensor temperature collection module to calculate a refrigeration temperature difference value, whether a second defrosting control strategy is executed or not is judged according to the refrigeration temperature difference value, and the problem that it is judged that the refrigerator fin evaporator is full of frost inaccurately is solved.

Description

Technical Field

[0001] The present application relates to the technical field of single-system air-cooled refrigerators, and in particular to a defrosting control method and device for determining whether a refrigerator fin evaporator is fully frosted. Background Art

[0002] Single-system air-cooled refrigerators use the cooling fan to bring the cold air in the fin evaporator cavity (usually located in the freezer) into different rooms for heat exchange, thereby cooling down each room of the refrigerator. During the air circulation process, the water vapor in each room will be brought back to the fin evaporator to condense into frost; when the frost layer becomes thicker, the cooling effect will deteriorate, and a defrost heater is needed to remove the frost on the fin evaporator.

[0003] In order to improve the refrigeration efficiency, the frosting condition of the refrigerator fin evaporator can be judged according to the ambient temperature, the cumulative running time of the compressor, the number of door openings and closings, etc., so as to generate a defrost control strategy. However, according to the ambient temperature, the cumulative running time of the compressor, the number of door openings and closings, etc., the frosting condition of the refrigerator fin evaporator can only be vaguely perceived. During the operation, the defrosting preset conditions are not met, but the evaporator is already full of frost. Summary of the invention

[0004] The present application provides a defrost control method and device for judging whether a refrigerator fin evaporator is fully frosted, so as to solve the problem of inaccurate judgment of whether a refrigerator fin evaporator is fully frosted.

[0005] A first aspect of the present application provides a defrost control method for determining whether a refrigerator fin evaporator is fully frosted, the method comprising:

[0006] The ambient temperature, average return air pipe temperature, door opening and closing times, and cumulative compressor operation time are collected through the ambient temperature collection module, return air pipe temperature collection module, switch quantity collection module, and compressor operation parameter collection module;

[0007] Generate an initial frost control strategy according to the ambient temperature, the number of door openings and closings, and the cumulative running time of the compressor;

[0008] According to the ambient temperature, the return air temperature and the refrigeration start-up point temperature of the refrigerator under load are obtained;

[0009] Calculating the return air temperature difference according to the return air pipe average temperature and the return air temperature;

[0010] If the return air temperature difference is greater than or equal to the first preset temperature value, executing the initialization frost control strategy;

[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, executing the first defrost control strategy;

[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 collection module;

[0013] A refrigeration temperature difference is calculated according to the refrigeration sensor temperature and the refrigeration start-up point temperature, so as to determine whether to execute the second defrost control strategy according to the refrigeration temperature difference.

[0014] The above method not only takes into account factors such as ambient temperature, number of door opening and closing, and cumulative running time of the compressor, but also comprehensively considers the changes in the return air temperature difference and the refrigeration temperature difference when the compressor is frosted. It can more effectively judge whether the fin evaporator is fully frosted, reduce the risk of abnormal temperature increase or food spoilage in non-freezer compartments, and solve the problem of inaccurate judgment of whether the refrigerator fin evaporator is fully frosted.

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

[0016] Determining whether the initialization frost condition is met according to the ambient temperature, the number of door openings and closings, and the cumulative running time of the compressor;

[0017] If the initial frost condition is met, the compressor is controlled to stop and the heater is controlled to turn on to heat the fin evaporator;

[0018] The fin evaporator temperature is obtained through the defrost sensor;

[0019] When the temperature of the fin evaporator reaches a preset evaporator temperature, controlling the heater to be turned off;

[0020] When the heater is turned off for a preset drip waiting time, the compressor is controlled to turn on again.

[0021] The temperature of the fin evaporator is obtained through the defrost sensor. When the temperature reaches the preset value, the heater is turned off to prevent the evaporator from overheating and protect the safety of the equipment. When the heater is turned off, the preset drip waiting time is used to ensure that the frost on the fin evaporator is completely melted to avoid residual frost affecting the heating effect.

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

[0023] When the start time of the compressor reaches the preset compressor start time, the return air pipe temperature is collected in real time through the return air pipe temperature collection module;

[0024] The average value of the return air pipe temperature in each preset compressor time period is calculated as the return air pipe average temperature.

[0025] The average return air duct temperature and the average ambient temperature can effectively reduce the impact of a single measurement error on the overall result, making the calculated average temperature more accurate and reliable, and helping to formulate a more reasonable defrost control strategy, thereby further improving operating efficiency and energy saving effects.

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

[0027] 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, continue to obtain the average temperature of the return air pipe in the next three preset compressor time periods to calculate the return air temperature difference for the next three times;

[0028] If any return air temperature difference is greater than or equal to the first preset temperature value, the initialization frost control strategy is executed;

[0029] If the difference between any two return air temperatures is less than the first preset temperature value and greater than or equal to the second preset temperature value, the total defrost interval in the initial frost control strategy is reduced by 5 hours;

[0030] If the difference between any two return air temperatures is less than the second preset temperature value, then continue to obtain the average temperature of the return air pipe in the next three preset compressor time periods to calculate the difference between the next three return air temperatures;

[0031] If the difference between any two return air temperatures is greater than or equal to the second preset temperature value, re-judge based on the last return air temperature difference;

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

[0033] A refrigeration temperature difference is calculated according to the refrigeration sensor temperature and the refrigeration start-up point temperature, so as to determine whether to execute the second defrost control strategy according to the refrigeration temperature difference.

[0034] By making a detailed analysis and judgment on the return air temperature difference, and choosing whether to perform more collection and judgment based on the judgment result, it is possible to more accurately judge when defrosting operation is required and how to perform defrosting operation.

[0035] Optionally, before collecting the refrigeration sensor temperature in real time by the refrigeration sensor temperature collection module, the method further includes:

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

[0037] If the difference between any two return air temperatures is greater than or equal to the second preset temperature value, re-judge based on the last return air temperature difference;

[0038] If the 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 collection module.

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

[0040] Calculating a refrigeration temperature difference according to the refrigeration sensor temperature and the refrigeration start-up point temperature;

[0041] If the refrigeration temperature difference is greater than or equal to the first preset refrigeration temperature, and the duration is greater than the first preset time, it is determined that the fin evaporator is full of frost;

[0042] 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 close;

[0043] When the closing time of the refrigeration auxiliary damper reaches a third preset time, recalculating the refrigeration temperature difference according to the refrigeration sensor temperature and the refrigeration start-up point temperature;

[0044] If the recalculated refrigeration temperature difference is greater than or equal to the first preset refrigeration temperature, it is determined that the fin evaporator is full of frost;

[0045] If the recalculated refrigeration temperature difference is less than the first preset refrigeration temperature and greater than the second preset refrigeration temperature, obtaining a duration during which the refrigeration temperature difference is greater than the second preset refrigeration temperature;

[0046] If the duration of the refrigeration temperature difference being greater than the second preset refrigeration temperature is greater than or equal to 3 hours, it is determined that the fin evaporator is fully frosted;

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

[0048] Based on the temperature change of the return air duct, the refrigeration auxiliary damper switch on the bottom outlet of the refrigeration air duct is controlled, and then the temperature change of the refrigeration sensor is judged. It can not only understand the actual situation of the refrigeration environment in real time, and dynamically adjust the defrost control strategy based on these data. It can also more accurately judge whether the fin evaporator is full of frost, so as to decide whether defrosting operation is needed, which helps to reduce unnecessary energy consumption and equipment wear, and improve the efficiency and life of the refrigerator.

[0049] Optionally, the second defrost 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 during which the refrigeration temperature difference within the fourth preset time is less than the third preset refrigeration temperature is greater than or equal to 10 minutes, executing the initialization frost control strategy;

[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 and greater than the second preset refrigeration temperature, recalculating the refrigeration temperature difference according to the refrigeration sensor temperature and the refrigeration start-up point temperature;

[0054] 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 fin evaporator is fully frosted.

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

[0056] The second aspect of the present application provides a defrost control device for judging whether a refrigerator fin evaporator is fully frosted, which is applicable to the defrost control method for judging whether a refrigerator fin evaporator is fully frosted as described in the first aspect, and the device comprises: a control unit, an ambient temperature acquisition module, a return air pipe temperature acquisition module, a refrigeration sensor temperature acquisition module, a switch quantity acquisition module, and a compressor operation parameter acquisition module; the control unit is electrically connected to the ambient temperature acquisition module, the return air pipe temperature acquisition module, the refrigeration sensor temperature acquisition module, the switch quantity acquisition module, and the compressor operation parameter acquisition module respectively; the control unit is configured as follows:

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

[0058] Generate an initial frost control strategy according to the ambient temperature, the number of door openings and closings, and the cumulative running time of the compressor;

[0059] According to the ambient temperature, the return air temperature and the refrigeration start-up point temperature of the refrigerator under load are obtained;

[0060] Calculating the return air temperature difference according to the return air pipe average temperature and the return air temperature;

[0061] If the return air temperature difference is greater than or equal to the first preset temperature value, executing the initialization frost control strategy;

[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, executing the first defrost control strategy;

[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 collection module;

[0064] A refrigeration temperature difference is calculated according to the refrigeration sensor temperature and the refrigeration start-up point temperature, so as to determine whether to execute the second defrost control strategy according to the refrigeration temperature difference.

[0065] The above device not only takes into account factors such as ambient temperature, number of door opening and closing, and cumulative running time of the compressor, but also comprehensively considers the changes in the return air temperature difference and the refrigeration temperature difference when the compressor is frosted. It can more effectively judge whether the fin evaporator is full of frost, reduce the risk of abnormal temperature increase or food spoilage in non-freezer compartments, and solve the problem of inaccurate judgment of whether the refrigerator fin evaporator is full of frost.

[0066] Optionally, the device further comprises a defrost sensor, which is arranged on the surface of the fin evaporator, and the control unit is electrically connected to the defrost sensor to collect the temperature of the fin evaporator in real time; the initialization frost control strategy comprises:

[0067] Determining whether the initialization frost condition is met according to the ambient temperature, the number of door openings and closings, and the cumulative running time of the compressor;

[0068] If the initial frost condition is met, the compressor is controlled to stop and the heater is controlled to turn on to heat the fin evaporator;

[0069] The fin evaporator temperature is obtained through the defrost sensor;

[0070] When the temperature of the fin evaporator reaches a preset evaporator temperature, controlling the heater to be turned off;

[0071] When the heater is turned off for a preset drip waiting time, the compressor is controlled to turn on again.

[0072] The temperature of the fin evaporator is obtained through the defrost sensor. When the temperature reaches the preset value, the heater is turned off to prevent the evaporator from overheating and protect the safety of the equipment. When the heater is turned off, the preset drip waiting time is used to ensure that the frost on the fin evaporator is completely melted to avoid residual frost affecting the heating effect.

[0073] Optionally, the device further comprises a refrigeration auxiliary damper, which is arranged on an air outlet air path at the bottom of the refrigerator refrigeration air duct; the control unit is electrically connected to the refrigeration auxiliary damper; and the control unit is further configured as follows:

[0074] Calculating a refrigeration temperature difference according to the refrigeration sensor temperature and the refrigeration start-up point temperature;

[0075] If the refrigeration temperature difference is greater than or equal to the first preset refrigeration temperature, and the duration is greater than the first preset time, it is determined that the fin evaporator is full of frost;

[0076] 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 close;

[0077] When the closing time of the refrigeration auxiliary damper reaches a third preset time, recalculating the refrigeration temperature difference according to the refrigeration sensor temperature and the refrigeration start-up point temperature;

[0078] If the recalculated refrigeration temperature difference is greater than or equal to the first preset refrigeration temperature, it is determined that the fin evaporator is full of frost;

[0079] If the recalculated refrigeration temperature difference is less than the first preset refrigeration temperature and greater than the second preset refrigeration temperature, obtaining a duration during which the refrigeration temperature difference is greater than the second preset refrigeration temperature;

[0080] If the duration of the refrigeration temperature difference being greater than the second preset refrigeration temperature is greater than or equal to 3 hours, it is determined that the fin evaporator is fully frosted;

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

[0082] Based on the temperature change of the return air duct, the refrigeration auxiliary damper switch on the bottom outlet of the refrigeration air duct is controlled, and then the temperature change of the refrigeration sensor is judged. It can not only understand the actual situation of the refrigeration environment in real time, and dynamically adjust the defrost control strategy based on these data. It can also more accurately judge whether the fin evaporator is full of frost, so as to decide whether defrosting operation is needed, which helps to reduce unnecessary energy consumption and equipment wear, and improve the efficiency and life of the refrigerator.

[0083] It can be seen from the above technical scheme that the present application provides a defrost control method and device for judging whether the refrigerator fin evaporator is full of frost, which collects the ambient temperature, the average temperature of the return air pipe, the number of door openings and closings, and the cumulative running time of the compressor through the ambient temperature collection module, the return air pipe temperature collection module, the switch quantity collection module, and the compressor operation parameter collection module; generates an initialization frost control strategy according to the ambient temperature, the number of door openings and closings, and the cumulative running time of the compressor; obtains the return air temperature and the refrigeration start-up point temperature when the refrigerator is loaded according to the ambient temperature; calculates the return air temperature difference according to the average return air pipe temperature and the return air temperature value; if the return air temperature difference is greater than or equal to the first preset temperature value, the initial frost control strategy is executed; 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 defrost control strategy is executed; 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; the refrigeration temperature difference is calculated according to the refrigeration sensor temperature and the refrigeration start-up point temperature, so as to determine whether to execute the second defrost control strategy according to the refrigeration temperature difference, so as to solve the problem of inaccurate judgment on whether the refrigerator fin evaporator is full of frost. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0085] Figure 1 A schematic flow chart of a defrost control method for determining whether a refrigerator fin evaporator is fully frosted provided in an embodiment of the present application;

[0086] Figure 2 A flow chart of a first defrost control strategy in a defrost control method for determining whether a refrigerator fin evaporator is fully frosted provided in an embodiment of the present application;

[0087] Figure 3 The present invention is a flow chart of the second defrost control strategy in the defrost control method for determining whether a refrigerator fin evaporator is fully frosted provided in an embodiment of the present application. DETAILED DESCRIPTION

[0088] The embodiments will be described in detail below, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation methods described in the following embodiments do not represent all implementation methods consistent with the present application. They are only examples of systems and methods consistent with some aspects of the present application.

[0089] Single-system air-cooled refrigerators use the cooling fan to bring the cold air in the fin evaporator cavity (usually located in the freezer) into different rooms for heat exchange, thereby cooling down each room of the refrigerator. During the air circulation process, the water vapor in each room will be brought back to the fin evaporator to condense into frost; when the frost layer becomes thicker, the cooling effect will deteriorate, and a defrost heater is needed to remove the frost on the fin evaporator.

[0090] In order to improve the refrigeration efficiency, the frosting condition of the refrigerator fin evaporator can be judged according to the ambient temperature, the cumulative running time of the compressor, the number of door openings and closings, etc., so as to generate a defrost control strategy. However, according to the ambient temperature, the cumulative running time of the compressor, the number of door openings and closings, etc., the frosting condition of the refrigerator fin evaporator can only be vaguely perceived. During the operation, the defrosting preset conditions are not met, but the evaporator is already full of frost.

[0091] In order to solve the problem of inaccurate judgment of whether the refrigerator fin evaporator is fully frosted, some embodiments of the present application provide a defrost control method for judging whether the refrigerator fin evaporator is fully frosted, which is applied to a defrost control device for judging whether the refrigerator fin evaporator is fully frosted, see Figure 1 , the method comprising:

[0092] S100: The ambient temperature average value Th, the return air pipe average temperature Tc, the number of door openings and closings, and the accumulated running time of the compressor are collected through the ambient temperature collection module, the return air pipe temperature collection module, the switch quantity collection module, and the compressor operation parameter collection module.

[0093] It should be understood that the ambient temperature collection module can be used to collect ambient temperature; the return air duct temperature collection module can be used to collect return air duct temperature; the switch quantity collection module can be used to collect the number of door openings and closings; and the compressor operating parameter collection module can be used to collect the cumulative operating time of the compressor.

[0094] In some embodiments, the step of obtaining the average temperature Tc of the return air duct by the return air duct temperature acquisition module includes:

[0095] When the start time of the compressor reaches the preset compressor start time t1, the return air pipe temperature is collected in real time through the return air pipe temperature collection module.

[0096] The average value of the return air pipe temperature in each preset compressor time period t2 is calculated as the return air pipe average temperature Tc.

[0097] It should be understood that the preset compressor startup time t1 can be selected as 10-30 minutes to allow the compressor to start and stabilize operation. The preset compressor time period t2 can be selected as 10-20 minutes. Similarly, the average value of the ambient temperature collected in the preset compressor time period t2 can be used as the ambient temperature average value Th.

[0098] The average return air duct temperature and the average ambient temperature can effectively reduce the impact of a single measurement error on the overall result, making the calculated average temperature more accurate and reliable, and helping to formulate a more reasonable defrost control strategy, thereby further improving operating efficiency and energy saving effects.

[0099] S200: generating an initialization frost control strategy according to the average ambient temperature Th, the number of door openings and closings, and the accumulated running time of the compressor.

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

[0101] Whether the initialization frost condition is met is determined according to the average ambient temperature Th, the number of door openings and closings, 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 door opening and closing times, and the cumulative running time of the compressor, other factors may also be used to determine whether the initialization frost condition is met.

[0103] If the initial frost condition is met, the compressor is controlled to stop and the heater is controlled to turn on to heat the fin evaporator.

[0104] The fin evaporator temperature is obtained through the defrost sensor.

[0105] When the temperature of the fin evaporator reaches the preset evaporator temperature, the heater is controlled to be turned off.

[0106] When the heater is turned off for a preset drip waiting time, the compressor is controlled to turn on again.

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

[0108] The temperature of the fin evaporator is obtained through the defrost sensor. When the temperature reaches the preset value, the heater is turned off to prevent the evaporator from overheating and protect the safety of the equipment. When the heater is turned off, the preset drip waiting time is used to ensure that the frost on the fin evaporator is completely melted to avoid residual frost affecting the heating effect.

[0109] S300: Obtaining the return air temperature Tc' and the refrigeration start-up point temperature Trk when the refrigerator is loaded according to the average ambient temperature Th.

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

[0111]

[0112] The refrigeration start-up point temperature Trk can also be calculated based on the average ambient temperature. The calculation formula can be:

[0113] Trk=Th-10℃.

[0114] S400: Calculating a return air temperature difference, ie, Tc-Tc', according to the return air pipe average temperature Tc and the return air temperature Tc'.

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

[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 defrost control strategy.

[0117] In some embodiments, see Figure 2 , the first defrost control strategy includes:

[0118] S610: 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, continue to obtain the average return air pipe temperature Tc of the next three preset compressor time periods t2 to calculate the next three return air temperature differences.

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

[0120] S630: If the difference between any two return air temperatures is less than the first preset temperature value N1 and greater than or equal to the second preset temperature value N2, the total defrost interval time in the initialization frost control strategy is reduced by 5 hours.

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

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

[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 difference between any two return air temperatures is less than the second preset temperature value N2, go to step S700.

[0124] By making a detailed analysis and judgment on the return air temperature difference, and choosing whether to perform more collection and judgment based on the judgment result, it is possible to more accurately judge when defrosting operation is required and how to perform 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 collection module.

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

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

[0128] If the difference between any two return air temperatures is greater than or equal to the second preset temperature value N2, a new determination is made based on the last return air temperature difference.

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

[0130] S800: Calculating a refrigeration temperature difference ΔT according to the refrigeration sensor temperature Tr and the refrigeration start-up point temperature Trk, so as to determine whether to execute a second defrosting control strategy according to the refrigeration temperature difference ΔT.

[0131] The above method not only takes into account factors such as ambient temperature, number of door opening and closing, and cumulative running time of the compressor, but also comprehensively considers the changes in the return air temperature difference and the refrigeration temperature difference when the compressor is frosted. It can more effectively judge whether the fin evaporator is fully frosted, reduce the risk of abnormal temperature increase or food spoilage in non-freezer compartments, and solve the problem of inaccurate judgment of whether the refrigerator fin evaporator is fully frosted.

[0132] In some embodiments, see Figure 3 , the second defrost control strategy includes:

[0133] S810: Calculate the refrigeration temperature difference ΔT according to the refrigeration sensor temperature Tr and the refrigeration start-up point 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, it is determined that the fin evaporator is fully frosted.

[0136] It should be understood that the value 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 damper to close.

[0138] It should be understood that the second preset refrigeration temperature has a value range of: 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 closing time of the refrigeration auxiliary damper reaches the third preset time t3, the refrigeration temperature difference ΔT is recalculated according to the refrigeration sensor temperature Tr and the refrigeration start-up point 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, it is determined that the fin evaporator is fully frosted.

[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 of the refrigeration temperature difference ΔT being greater than the second preset refrigeration temperature n2.

[0143] S861: If the duration that the refrigeration temperature difference ΔT is greater than the second preset refrigeration temperature n2 is greater than or equal to 3 hours, it is determined that the fin evaporator is fully frosted.

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

[0145] It should be understood that after determining that the fin evaporator is fully frosted, the compressor will be controlled to be turned on again when the time reaches 6 hours, and the compressor will be immediately controlled to stop and the heater will be controlled to be turned on to heat the fin evaporator.

[0146] Based on the temperature change of the return air duct, the refrigeration auxiliary damper switch on the bottom outlet of the refrigeration air duct is controlled, and then the temperature change of the refrigeration sensor is judged. It can not only understand the actual situation of the refrigeration environment in real time, and dynamically adjust the defrost control strategy based on these data. It can also more accurately judge whether the fin evaporator is full of frost, so as to decide whether defrosting operation is needed, which helps to reduce unnecessary energy consumption and equipment wear, and improve the efficiency and life of the refrigerator.

[0147] In some embodiments, the second defrost 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 time during which the refrigeration temperature difference ΔT within the fourth preset time is less than the third preset refrigeration temperature n3 is greater than or equal to 10 minutes, the initialization 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 according to the refrigeration sensor temperature Tr and the refrigeration start-up point temperature Trk.

[0152] If after the fourth preset time, the refrigeration temperature difference ΔT is greater than or equal to the first preset refrigeration temperature n1, it is determined that the fin evaporator is fully frosted.

[0153] It should be understood that the value 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. In addition, if the recalculated refrigeration temperature difference ΔT is less than or equal to the third preset refrigeration temperature n3, the initialization frost control strategy is executed.

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

[0155] It should be understood that the single-system air-cooled refrigerator includes a compressor, a condenser, a fan, a capillary tube or an expansion valve, a filter dryer, a defrosting device, and a control unit. Among them, the compressor is one of the core components of the air-cooled refrigerator, which is responsible for compressing the refrigerant into a high-temperature and high-pressure gas to provide power for the refrigeration cycle. The fin evaporator is located inside the refrigerator. When the refrigerant evaporates in the fin evaporator, it absorbs the heat of the surrounding air, which reduces the surface temperature of the fin evaporator, thereby achieving refrigeration inside the refrigerator. The condenser is used to cool and condense the high-temperature and high-pressure refrigerant gas output by the compressor into a liquid. In the condenser, the refrigerant releases heat and dissipates the heat to the outside through the surrounding air or heat sink. The fan is divided into an internal fan and an external fan. The internal fan is mainly used to force air to circulate inside the refrigerator so that the cold air can be evenly distributed in every corner to improve the refrigeration effect; the external fan is used to accelerate the heat dissipation of the condenser and improve the refrigeration efficiency. The capillary tube or expansion valve is a component connecting the condenser and the fin evaporator, which is used to control the flow and pressure of the refrigerant. It can adjust the evaporation speed and evaporation amount of the refrigerant in the finned evaporator, thereby controlling the cooling capacity. The dry filter is installed between the condenser and the capillary tube to filter impurities and moisture in the refrigerant to prevent impurities and moisture from entering the capillary tube and the finned evaporator, causing blockage and ice blockage. The defrosting device melts the frost into water through the heater, and then discharges the water out of the refrigerator through the drainage system.

[0156] Some embodiments of the present application also provide a defrost control device for determining whether the refrigerator fin evaporator is fully frosted, which is applicable to the defrost control method for determining whether the refrigerator fin evaporator is fully frosted as described in the above embodiments. The device includes: a control unit, an ambient temperature acquisition module, a return air pipe temperature acquisition module, a refrigeration 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 air pipe temperature acquisition module, the refrigeration 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 arranged on the surface of the refrigerator. The return air duct temperature acquisition module is arranged on the return air duct inside the refrigerator. The refrigeration sensor temperature acquisition module is arranged on the refrigeration sensor. The switch quantity acquisition module is arranged near the refrigerator door. The compressor operation parameter acquisition module is electrically connected to the compressor and can collect the compressor switching time.

[0158] The control unit is configured to:

[0159] The ambient temperature acquisition module, the return air pipe temperature acquisition module, the switch quantity acquisition module and the compressor operation parameter acquisition module are used to obtain the average ambient temperature Th, the average return air pipe temperature Tc, the number of door openings and closings and the cumulative operation time of the compressor;

[0160] Generate an initialization frost control strategy according to the average value of the ambient temperature Th, the number of door openings and closings, and the cumulative running time of the compressor;

[0161] According to the average ambient temperature Th, the return air temperature Tc' and the refrigeration start-up point temperature Trk of the refrigerator under load are obtained;

[0162] Calculating the return air temperature difference according to the return air pipe average temperature Tc and the return air temperature Tc';

[0163] If the return air temperature difference is greater than or equal to the first preset temperature value N1, the initialization 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 defrost 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 collection module;

[0166] A refrigeration temperature difference ΔT is calculated according to the refrigeration sensor temperature Tr and the refrigeration start-up point temperature Trk, so as to determine whether to execute the second defrosting control strategy according to the refrigeration temperature difference ΔT.

[0167] The above device not only takes into account factors such as ambient temperature, number of door opening and closing, and cumulative running time of the compressor, but also comprehensively considers the changes in the return air temperature difference and the refrigeration temperature difference when the compressor is frosted. It can more effectively judge whether the fin evaporator is full of frost, reduce the risk of abnormal temperature increase or food spoilage in non-freezer compartments, and solve the problem of inaccurate judgment of whether the refrigerator fin evaporator is full of frost.

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

[0169] The initialization frost control strategy includes:

[0170] Determine whether the initialization frost condition is met according to the average value of the ambient temperature Th, the number of door openings and closings, and the cumulative running time of the compressor;

[0171] If the initial frost condition is met, the compressor is controlled to stop and the heater is controlled to turn on to heat the fin evaporator;

[0172] The fin evaporator temperature is obtained through the defrost sensor;

[0173] When the temperature of the fin evaporator reaches a preset evaporator temperature, controlling the heater to be turned off;

[0174] When the heater is turned off for a preset drip waiting time, the compressor is controlled to turn on again.

[0175] The temperature of the fin evaporator is obtained through the defrost sensor. When the temperature reaches the preset value, the heater is turned off to prevent the evaporator from overheating and protect the safety of the equipment. When the heater is turned off, the preset drip waiting time is used to ensure that the frost on the fin evaporator is completely melted to avoid residual frost affecting the heating effect.

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

[0177] It should be understood that for a refrigerator with a refrigeration sensor located at the bottom of the refrigeration chamber, even if the top of the refrigeration chamber is too high due to the full frost on the fin evaporator, the air outlet at the bottom of the refrigeration chamber still has enough air volume to cool down the refrigeration sensor, so that it cannot truly reflect the room temperature. To cope with this situation, the refrigeration auxiliary damper needs to be installed on the air path at the bottom of the refrigeration chamber.

[0178] The control unit is further configured to:

[0179] Calculate the refrigeration temperature difference ΔT according to the refrigeration sensor temperature Tr and the refrigeration start-up point 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, it is determined that the fin evaporator is full of frost;

[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 damper is controlled to close;

[0182] When the closing time of the refrigeration auxiliary damper reaches a third preset time, the refrigeration temperature difference ΔT is recalculated according to the refrigeration sensor temperature Tr and the refrigeration start-up point temperature Trk;

[0183] If the recalculated refrigeration temperature difference ΔT is greater than or equal to the first preset refrigeration temperature, it is determined that the fin evaporator is full of frost;

[0184] If the recalculated refrigeration temperature difference ΔT is less than the first preset refrigeration temperature and greater than the second preset refrigeration temperature, obtaining a duration during 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, it is determined that the fin evaporator is fully frosted;

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

[0187] Based on the temperature change of the return air duct, the refrigeration auxiliary damper switch on the bottom outlet of the refrigeration air duct is controlled, and then the temperature change of the refrigeration sensor is judged. It can not only understand the actual situation of the refrigeration environment in real time, and dynamically adjust the defrost control strategy based on these data. It can also more accurately judge whether the fin evaporator is full of frost, so as to decide whether defrosting operation is needed, which helps to reduce unnecessary energy consumption and equipment wear, and improve the efficiency and life of the refrigerator.

[0188] It can be seen from the above technical scheme that the embodiment of the present application provides a defrost control method and device for judging whether the refrigerator fin evaporator is full of frost, and collects the average value of the ambient temperature Th, the average temperature of the return air pipe Tc, the number of door openings and closings, and the cumulative running time of the compressor through the ambient temperature collection module, the return air pipe temperature collection module, the switch quantity collection module, and the compressor operation parameter collection module; generates an initialization frost control strategy according to the average value of the ambient temperature Th, the number of door openings and closings, and the cumulative running time of the compressor; obtains the return air temperature Tc' and the refrigeration start-up point temperature Trk when the refrigerator is loaded according to the average value of the ambient temperature Th; calculates the return air pipe average temperature Tc and the return air temperature Tc' according to the average temperature of the return air pipe 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 frost control strategy; 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 defrost control strategy; if the return air temperature difference is less than the second preset temperature value N2, collect the refrigeration sensor temperature Tr in real time through the refrigeration sensor temperature acquisition module; calculate the refrigeration temperature difference ΔT according to the refrigeration sensor temperature Tr and the refrigeration start-up point temperature Trk, and judge whether to execute the second defrost control strategy according to the refrigeration temperature difference ΔT, so as to solve the problem of inaccurate judgment of whether the refrigerator fin evaporator is full of frost.

[0189] Similar parts between the embodiments provided in this application can be referenced to each other. The specific implementation methods provided above are only a few examples under the general concept of this application and do not constitute a limitation on the protection scope of this application. For those skilled in the art, any other implementation methods expanded based on the scheme of this application without creative work belong to the protection scope of this application.

Claims

1. A defrosting control method for judging whether a refrigerator fin evaporator is fully frosted, characterized in that: The method comprises: The ambient temperature, average return air pipe temperature, door opening and closing times, and cumulative compressor operation time are collected through the ambient temperature collection module, return air pipe temperature collection module, switch quantity collection module, and compressor operation parameter collection module; Generate an initial frost control strategy according to the ambient temperature, the number of door openings and closings, and the cumulative running time of the compressor; According to the ambient temperature, the return air temperature and the refrigeration start-up point temperature of the refrigerator under load are obtained; Calculating the return air temperature difference according to the return air pipe average temperature and the return air temperature; If the return air temperature difference is greater than or equal to the first preset temperature value, executing the initialization frost control strategy; 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, executing the first defrost control strategy; 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 collection module; A refrigeration temperature difference is calculated according to the refrigeration sensor temperature and the refrigeration start-up point temperature, so as to determine whether to execute the second defrost control strategy according to the refrigeration temperature difference.

2. The defrost control method for judging whether the refrigerator fin evaporator is fully frosted according to claim 1, characterized in that: The initialization frost control strategy includes: Determining whether the initialization frost condition is met according to the ambient temperature, the number of door openings and closings, and the cumulative running time of the compressor; If the initial frost condition is met, the compressor is controlled to stop and the heater is controlled to turn on to heat the fin evaporator; The fin evaporator temperature is obtained through the defrost sensor; When the temperature of the fin evaporator reaches a preset evaporator temperature, controlling the heater to be turned off; When the heater is turned off for a preset drip waiting time, the compressor is controlled to turn on again.

3. The defrost control method for judging whether the refrigerator fin evaporator is fully frosted according to claim 1, characterized in that: The steps of obtaining the average temperature of the return air pipe by the return air pipe temperature acquisition module include: When the start time of the compressor reaches the preset compressor start time, the return air pipe temperature is collected in real time through the return air pipe temperature collection module; The average value of the return air pipe temperature in each preset compressor time period is calculated as the return air pipe average temperature.

4. The defrost control method for judging whether the refrigerator fin evaporator is fully frosted according to claim 3, characterized in that: The first defrost control strategy includes: 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, continue to obtain the average temperature of the return air pipe in the next three preset compressor time periods to calculate the return air temperature difference for the next three times; If any return air temperature difference is greater than or equal to the first preset temperature value, the initialization frost control strategy is executed; If the difference between any two return air temperatures is less than the first preset temperature value and greater than or equal to the second preset temperature value, the total defrost interval in the initial frost control strategy is reduced by 5 hours; If the difference between any two return air temperatures is less than the second preset temperature value, then continue to obtain the average temperature of the return air pipe in the next three preset compressor time periods to calculate the difference between the next three return air temperatures; If the difference between any two return air temperatures is greater than or equal to the second preset temperature value, re-judge based on the last return air temperature difference; If the difference between any two return air temperatures is less than the second preset temperature value, the refrigeration sensor temperature is collected in real time through the refrigeration sensor temperature collection module; A refrigeration temperature difference is calculated according to the refrigeration sensor temperature and the refrigeration start-up point temperature, so as to determine whether to execute the second defrost control strategy according to the refrigeration temperature difference.

5. The defrost control method for judging whether the refrigerator fin evaporator is fully frosted according to claim 4, characterized in that: Before collecting the refrigeration sensor temperature in real time through the refrigeration sensor temperature collection module, the method further includes: If the return air temperature difference is less than the second preset temperature value, continue to obtain the average temperature of the return air pipe in the next three preset compressor time periods to calculate the return air temperature difference for the next three times; If the difference between any two return air temperatures is greater than or equal to the second preset temperature value, re-judge based on the last return air temperature difference; If the 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 collection module.

6. The defrosting control method for judging whether the refrigerator fin evaporator is fully frosted according to claim 5, characterized in that: The second defrost control strategy includes: Calculating a refrigeration temperature difference according to the refrigeration sensor temperature and the refrigeration start-up point temperature; If the refrigeration temperature difference is greater than or equal to the first preset refrigeration temperature, and the duration is greater than the first preset time, it is determined 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 close; When the closing time of the refrigeration auxiliary damper reaches a third preset time, recalculating the refrigeration temperature difference according to the refrigeration sensor temperature and the refrigeration start-up point temperature; If the recalculated refrigeration temperature difference is greater than or equal to the first preset refrigeration temperature, it is determined that the fin 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, obtaining a duration during which the refrigeration temperature difference is greater than the second preset refrigeration temperature; If the duration of the refrigeration temperature difference being greater than the second preset refrigeration temperature is greater than or equal to 3 hours, it is determined that the fin evaporator is fully frosted; If the duration that the refrigeration temperature difference is greater than the second preset refrigeration temperature is less than 3 hours, continue to obtain the duration that the refrigeration temperature difference is greater than the second preset refrigeration temperature.

7. The defrost control method for judging whether the refrigerator fin evaporator is fully frosted according to claim 6, characterized in that: The second defrost control strategy also includes: 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; If the time during which the refrigeration temperature difference within the fourth preset time is less than the third preset refrigeration temperature is greater than or equal to 10 minutes, executing the initialization frost control strategy; 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; 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, recalculating the refrigeration temperature difference according to the refrigeration sensor temperature and the refrigeration start-up 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 fin evaporator is fully frosted.

8. A defrost control device for judging whether a refrigerator fin evaporator is fully frosted, characterized in that: The defrost control method for judging whether the refrigerator fin evaporator is fully frosted is applicable to any one of claims 1 to 7, wherein the device comprises: a control unit, an ambient temperature acquisition module, a return air pipe temperature acquisition module, a refrigeration sensor temperature acquisition module, a switch quantity acquisition module, and a compressor operation parameter acquisition module; the control unit is electrically connected to the ambient temperature acquisition module, the return air pipe temperature acquisition module, the refrigeration sensor temperature acquisition module, the switch quantity acquisition module, and the compressor operation parameter acquisition module respectively; the control unit is configured as follows: The ambient temperature, the average temperature of the return air pipe, the number of door openings and closings, and the cumulative running time of the compressor are obtained through the ambient temperature acquisition module, the return air pipe temperature acquisition module, the switch quantity acquisition module, and the compressor operation parameter acquisition module; Generate an initial frost control strategy according to the ambient temperature, the number of door openings and closings, and the cumulative running time of the compressor; According to the ambient temperature, the return air temperature and the refrigeration start-up point temperature of the refrigerator under load are obtained; Calculating the return air temperature difference according to the return air pipe average temperature and the return air temperature; If the return air temperature difference is greater than or equal to the first preset temperature value, executing the initialization frost control strategy; 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, executing the first defrost control strategy; 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 collection module; A refrigeration temperature difference is calculated according to the refrigeration sensor temperature and the refrigeration start-up point temperature, so as to determine whether to execute the second defrost control strategy according to the refrigeration temperature difference.

9. The defrost control device for judging whether the refrigerator fin evaporator is fully frosted according to claim 8, characterized in that: It also includes a defrost sensor, which is arranged on the surface of the fin evaporator, and the control unit is electrically connected to the defrost sensor to collect the temperature of the fin evaporator in real time; The initialization frost control strategy includes: Determining whether the initialization frost condition is met according to the ambient temperature, the number of door openings and closings, and the cumulative running time of the compressor; If the initial frost condition is met, the compressor is controlled to stop and the heater is controlled to turn on to heat the fin evaporator; The fin evaporator temperature is obtained through the defrost sensor; When the temperature of the fin evaporator reaches a preset evaporator temperature, controlling the heater to be turned off; When the heater is turned off for a preset drip waiting time, the compressor is controlled to turn on again.

10. The defrost control device for judging whether the refrigerator fin evaporator is fully frosted according to claim 8, characterized in that: The refrigerator further comprises a refrigeration auxiliary damper, which is arranged on an air outlet wind path at the bottom of the refrigeration air duct of the refrigerator; the control unit is electrically connected to the refrigeration auxiliary damper; and the control unit is further configured as follows: Calculating a refrigeration temperature difference according to the refrigeration sensor temperature and the refrigeration start-up point temperature; If the refrigeration temperature difference is greater than or equal to the first preset refrigeration temperature, and the duration is greater than the first preset time, it is determined 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 close; When the closing time of the refrigeration auxiliary damper reaches a third preset time, recalculating the refrigeration temperature difference according to the refrigeration sensor temperature and the refrigeration start-up point temperature; If the recalculated refrigeration temperature difference is greater than or equal to the first preset refrigeration temperature, it is determined that the fin 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, obtaining a duration during which the refrigeration temperature difference is greater than the second preset refrigeration temperature; If the duration of the refrigeration temperature difference being greater than the second preset refrigeration temperature is greater than or equal to 3 hours, it is determined that the fin evaporator is fully frosted; If the duration that the refrigeration temperature difference is greater than the second preset refrigeration temperature is less than 3 hours, continue to obtain the duration that the refrigeration temperature difference is greater than the second preset refrigeration temperature.

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