Defrosting control methods and refrigeration equipment

Abstract

This invention provides a defrosting control method and refrigeration equipment. The method includes: preset defrosting conditions; if the defrosting conditions are met, calculating a first return gas pipe temperature difference, where the first return gas pipe temperature difference is the difference between the average temperature of the return gas pipe and the return gas temperature before the defrosting conditions are met; if the first return gas pipe temperature difference is less than a first temperature difference threshold and greater than or equal to a second temperature difference threshold, executing a first defrosting command; if the first return gas pipe temperature difference is less than the second temperature difference threshold and greater than or equal to a third temperature difference threshold, executing a second defrosting command; if the first return gas pipe temperature difference is less than the third temperature difference threshold, executing a third defrosting command. This method, by calculating the return gas pipe temperature difference and dynamically adjusting the defrosting command based on changes in the return gas pipe temperature difference, can more accurately determine the frosting status of the finned evaporator, reduce unnecessary defrosting cycles, and lower energy consumption.

Description

Technical Field

[0001] This application relates to the field of defrosting control technology, and in particular to a defrosting control method and refrigeration equipment. Background Technology

[0002] During the operation of refrigeration equipment, when cold air passes through the finned evaporator, the water vapor in it will condense on the low-temperature surface and gradually form a frost or ice layer. The frost layer will hinder the heat exchange between the refrigerant and the outside air, resulting in a decrease in heat transfer efficiency. When the finned evaporator is covered with frost, its ability to absorb heat is weakened, causing the refrigeration equipment to be unable to effectively lower the temperature.

[0003] To improve cooling efficiency, defrosting can be achieved through defrosting control methods. For example, the frost condition of the refrigerator fin evaporator can be determined by factors such as ambient temperature, cumulative compressor running time, and number of door openings and closings, thereby adjusting the defrosting control strategy for effective defrosting.

[0004] However, based on the above-mentioned jump, it can only detect the frosting situation of the finned evaporator. When the preset conditions are met, the finned evaporator will only be partially frosted. At this time, defrosting will be started, resulting in energy waste. Summary of the Invention

[0005] This application provides a defrosting control method and a refrigeration device to solve the problem of energy waste during the defrosting process.

[0006] In a first aspect, this application provides a defrosting control method, comprising:

[0007] Preset defrosting conditions;

[0008] If the defrosting conditions are met, calculate the temperature difference of the first return pipe. The temperature difference of the first return pipe is the difference between the average temperature of the return pipe and the return gas temperature before the defrosting conditions are met.

[0009] If the temperature difference of the first return gas pipe is less than the first temperature difference threshold and greater than or equal to the second temperature difference threshold, execute the first defrosting command;

[0010] If the temperature difference of the first return gas pipe is less than the second temperature difference threshold and greater than or equal to the third temperature difference threshold, execute the second defrosting command;

[0011] If the temperature difference of the first return gas pipe is less than the third temperature difference threshold, execute the third defrosting command.

[0012] In some feasible embodiments, the defrosting conditions include at least the ambient temperature, the cumulative operating time of the compressor, and the number of times the door is opened and closed;

[0013] If the defrosting conditions are met, the calculation of the temperature difference in the first return gas pipe includes:

[0014] Acquire ambient temperature, cumulative compressor running time, and number of door openings and closings;

[0015] If the ambient temperature is less than the ambient temperature threshold, or the compressor's cumulative running time is greater than the time threshold, or the number of door openings and closings is greater than the number of openings and closings threshold, obtain the average temperature of the return gas pipe.

[0016] Calculate the average value of the ambient temperature and match the return air temperature based on the average value;

[0017] The temperature difference of the first return gas pipe is calculated by using the average temperature of the return gas pipe and the return gas temperature.

[0018] In some feasible embodiments, matching the return gas temperature based on the average value includes:

[0019] If the average value is less than or equal to the first temperature, a first return gas temperature is matched, where the first return gas temperature is the difference between the average temperature of the return gas pipe and a first preset value.

[0020] If the average value is greater than the first temperature and less than or equal to the second temperature, a second return gas temperature is matched. The second return gas temperature is the difference between the average temperature of the return gas pipe and a second preset value, and the second preset value is greater than the first preset value.

[0021] If the average value is greater than the second temperature, a third return gas temperature is matched. The third return gas temperature is the difference between the average temperature of the return gas pipe and a third preset value, and the third preset value is greater than the second preset value.

[0022] In some feasible embodiments, the step of executing a first defrosting command if the temperature difference of the first return gas pipe is less than a first temperature difference threshold and greater than or equal to a second temperature difference threshold includes:

[0023] If the temperature difference of the first return gas pipe is less than the first temperature difference threshold and greater than or equal to the second temperature difference threshold, a first preset number of second return gas pipe temperature differences are obtained. The second return gas pipe temperature difference is the return gas pipe temperature difference obtained after obtaining the first return gas pipe temperature difference.

[0024] If a preset proportion of the second return gas pipe temperature difference in the first preset quantity is less than the first temperature difference threshold, but greater than or equal to the second temperature difference threshold, the first defrosting instruction is set to execute defrosting after the defrosting interval time is increased by the first time.

[0025] If a preset proportion of the second return gas pipe temperature difference in the first preset quantity is less than the second temperature difference threshold and greater than or equal to the third temperature difference threshold, execute the second defrosting command.

[0026] If the temperature difference of the second return gas pipe in the first preset quantity is less than the third temperature difference threshold, execute the third defrosting command.

[0027] In some feasible embodiments, the step of executing a second defrosting command if the temperature difference of the first return gas pipe is less than a second temperature difference threshold and greater than or equal to a third temperature difference threshold includes:

[0028] If the temperature difference of the first return gas pipe is less than the second temperature difference threshold and greater than or equal to the third temperature difference threshold, a second preset number of third return gas pipe temperature differences are obtained, wherein the third return gas pipe temperature difference is the return gas pipe temperature difference before the first return gas pipe temperature difference is obtained.

[0029] The cumulative duration during which the temperature difference of the third return air pipe is less than the second temperature difference threshold is obtained (for a second preset number of times).

[0030] If the cumulative duration is less than the first duration, a second defrost command is set to add a second time to the defrost interval, where the second time is less than the first time.

[0031] In some feasible embodiments, the step of executing a second defrosting command if the temperature difference of the first return gas pipe is less than a second temperature difference threshold and greater than or equal to a third temperature difference threshold further includes:

[0032] If the cumulative duration is greater than or equal to the first duration and less than the second duration, obtain the cumulative duration for which the temperature difference of the third return air pipe is less than the second temperature difference threshold, which is a first preset number.

[0033] If the cumulative duration is greater than or equal to the second duration, calculate the defrosting time, where the defrosting time is the time since the last defrosting was completed.

[0034] If the defrosting time is greater than or equal to the first time, the second defrosting command is set to execute defrosting.

[0035] In some feasible embodiments, the step of executing a third defrosting command if the temperature difference of the first return gas pipe is less than a third temperature difference threshold includes:

[0036] If the temperature difference of the first return gas pipe is less than the third temperature difference threshold, the temperature difference of the fourth return gas pipe is obtained. The fourth return gas pipe temperature difference is the return gas pipe temperature difference before the first return gas pipe temperature difference is obtained.

[0037] If a preset proportion of the fourth return air pipe temperature difference in the first preset quantity is less than the third temperature difference threshold, the defrosting time is calculated, where the defrosting time is the time since the last defrosting was completed.

[0038] If the defrosting time is greater than or equal to the first time, the third defrosting command is set to execute defrosting.

[0039] In some feasible embodiments, the method further includes:

[0040] If the temperature difference of the fourth return air pipe in the first preset quantity is greater than or equal to the third temperature difference threshold and less than the second temperature difference threshold, execute the second defrosting command.

[0041] If there is no fourth return pipe temperature difference less than the third temperature difference threshold in the first preset quantity, or if there is no fourth return pipe temperature difference greater than or equal to the third temperature difference threshold in the first preset quantity and less than the second temperature difference threshold, the fifth return pipe temperature difference of the third preset quantity is obtained. The fifth return pipe temperature difference is the return pipe temperature difference obtained after obtaining the first return pipe temperature difference.

[0042] Based on the fifth return pipe temperature difference of a third preset number, the sixth return pipe temperature difference of a first preset number is obtained, so as to obtain a defrosting command through the sixth return pipe temperature difference. The sixth return pipe temperature difference is the return pipe temperature difference obtained after obtaining the fifth return pipe temperature difference. The defrosting command includes a first defrosting command, a second defrosting command, and a third defrosting command.

[0043] In some feasible embodiments, the method further includes:

[0044] If the temperature difference of the first return air pipe is greater than or equal to the first temperature difference threshold, the defrosting command is not executed.

[0045] Secondly, this application provides a refrigeration device, comprising:

[0046] The control unit is configured to preset defrost conditions;

[0047] The temperature acquisition module is configured to calculate the first return gas pipe temperature difference if the defrosting conditions are met. The first return gas pipe temperature difference is the difference between the average temperature of the return gas pipe and the return gas temperature before the defrosting conditions are met.

[0048] The control unit is also configured to:

[0049] If the temperature difference of the first return gas pipe is less than the first temperature difference threshold and greater than or equal to the second temperature difference threshold, execute the first defrosting command;

[0050] If the temperature difference of the first return gas pipe is less than the second temperature difference threshold and greater than or equal to the third temperature difference threshold, execute the second defrosting command;

[0051] If the temperature difference of the first return gas pipe is less than the third temperature difference threshold, execute the third defrosting command.

[0052] As can be seen from the above technical solutions, this application provides a defrosting control method and refrigeration equipment. The method includes: preset defrosting conditions; if the defrosting conditions are met, calculating a first return gas pipe temperature difference, where the first return gas pipe temperature difference is the difference between the average temperature of the return gas pipe and the return gas temperature before the defrosting conditions are met; if the first return gas pipe temperature difference is less than a first temperature difference threshold and greater than or equal to a second temperature difference threshold, executing a first defrosting command; if the first return gas pipe temperature difference is less than the second temperature difference threshold and greater than or equal to a third temperature difference threshold, executing a second defrosting command; if the first return gas pipe temperature difference is less than the third temperature difference threshold, executing a third defrosting command. This method, by calculating the return gas pipe temperature difference and dynamically adjusting the defrosting command based on changes in the return gas pipe temperature difference, can more accurately determine the frosting status of the finned evaporator, reduce unnecessary defrosting cycles, and reduce energy consumption. Attached Figure Description

[0053] 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.

[0054] Figure 1 A schematic diagram illustrating the process of controlling defrosting through preset conditions, provided for an embodiment of this application;

[0055] Figure 2 This is a schematic diagram of the defrosting control method provided in the embodiments of this application;

[0056] Figure 3 This is a schematic diagram of the second return gas pipe temperature difference processing provided in an embodiment of this application;

[0057] Figure 4 This is a schematic diagram of the third return gas pipe temperature difference processing provided in the embodiments of this application. Detailed Implementation

[0058] 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 as detailed in the claims.

[0059] Defrosting is a maintenance operation performed on refrigeration equipment, such as refrigerators and air conditioners, to remove frost or ice that forms on the surface of the finned evaporator.

[0060] Over time, as cold air passes through the finned evaporator, water vapor condenses on the low-temperature surface, gradually forming a frost or ice layer. This frost layer hinders heat exchange between the refrigerant and the outside air, leading to a decrease in heat transfer efficiency. If this frost layer is not removed in time, the effective heat exchange area of ​​the finned evaporator will be reduced, thus affecting the overall cooling effect of the refrigeration equipment.

[0061] When the finned evaporator is covered in frost, its ability to absorb heat is reduced, causing refrigerators or air conditioners to be unable to effectively lower the temperature. In refrigerators, food may not be sufficiently cooled or frozen; in air conditioners, the room temperature cools down more slowly, or may not even reach the set temperature. Defrosting restores the finned evaporator's efficiency, ensuring the refrigeration system functions properly and maintains the required temperature level.

[0062] A finned evaporator is a component in a refrigeration system that increases heat exchange efficiency by increasing surface area. In some embodiments, a finned evaporator includes tubes, fins, a frame, and connectors.

[0063] The refrigerant flowing inside the tubes is low-temperature and low-pressure. The finned evaporator is composed of a series of parallel, slender metal tubes. Each tube is covered with thin and dense metal fins. The fins increase the effective surface area in contact with the surrounding air, thereby improving the heat exchange efficiency.

[0064] To support the finned evaporator and ensure smooth airflow, the finned evaporator is mounted in a robust frame, and connectors are used to connect the refrigerant inlet and outlet to other parts of the system, such as the compressor, condenser, etc.

[0065] When refrigerant flows through a finned evaporator, it changes from a liquid to a gaseous state, absorbing a large amount of heat in the process. This process occurs inside the tubes, while the heat comes from the surrounding air or liquid medium. The function of the fins is to increase the heat exchange area, allowing more heat to be transferred from the surrounding air to the refrigerant. As the refrigerant temperature rises, it begins to evaporate, carrying away a significant amount of heat in the process, thus cooling the air or liquid passing through the finned evaporator.

[0066] To ensure optimal heat exchange, finned evaporators can also be used in conjunction with fans or other devices to guide airflow through the gaps between the fins, thereby maximizing heat transfer efficiency.

[0067] The finned evaporator in a refrigerator is located inside or near the freezer compartment. Because the internal environment of a refrigerator is relatively enclosed and the temperature is low, frost is easily formed. Therefore, the finned evaporator of a refrigerator needs to be specially designed to delay frost formation and should be used in conjunction with timed defrosting or frost-free technology.

[0068] Air conditioner finned evaporators need to be able to handle a wider range of temperature and humidity variations, especially under high temperature and humidity conditions in summer. Air conditioners may also produce frost under certain conditions, but their defrosting mechanism is automated and can be completed without affecting user comfort. To achieve rapid cooling and energy-saving operation, the design of air conditioner finned evaporators places greater emphasis on optimized airflow, corrosion resistance, and ease of cleaning and maintenance.

[0069] The presence of frost not only reduces cooling efficiency, but also forces compressors and other components to increase power or work in other ways to compensate for the lost energy, thereby increasing energy consumption. Regular defrosting helps maintain the system in optimal operating condition, avoids unnecessary power waste, and reduces operating costs.

[0070] Excessive frost buildup can cause physical damage to internal components of refrigeration equipment, such as increasing mechanical stress, causing fan blade imbalance, or short-circuiting electrical connections due to moisture. A proper defrosting procedure can help protect these sensitive components from damage and extend the overall lifespan of the equipment.

[0071] In air conditioners, a thick layer of frost can block air ducts, restrict airflow, and affect indoor air quality and cooling / heating efficiency. Removing the frost layer ensures normal air circulation, allowing the air conditioner to regulate room temperature more evenly and helping to maintain good indoor environmental quality.

[0072] In summary, defrosting ensures that refrigeration equipment can operate efficiently and reliably, while saving energy and protecting the equipment from damage.

[0073] Defrosting mechanisms can include various methods, such as defrosting by regular periods, defrosting by cumulative operating time, defrosting based on temperature and humidity conditions, defrosting based on the number of times the door is opened and closed, and comprehensive defrosting control.

[0074] In some embodiments, the defrosting process is automatically triggered at fixed time intervals. For example, a refrigerator or air conditioner may be programmed to defrost every 6 hours, 12 hours, or 24 hours. No additional sensors are required, making it suitable for everyday use. However, it cannot adapt to changes in actual frost conditions, potentially leading to unnecessary defrosting operations and wasted energy.

[0075] Defrosting based on cumulative operating time involves recording the compressor's cumulative operating time. When a preset threshold is reached, the defrosting process is initiated. This method assumes that the frost layer on the evaporator will gradually thicken as the compressor's operating time increases. While considering the actual workload of the equipment, the lack of direct measurement of specific frost conditions may lead to premature or delayed defrosting during low-load operation.

[0076] Temperature and humidity condition defrosting combines ambient temperature and humidity levels to predict the likelihood of frost formation. For example, frost is more likely to form under low temperature and high humidity conditions, thus allowing for adjustments to the defrosting frequency. This method better reflects the impact of the external environment on frost formation and improves the accuracy of defrosting decisions. However, it requires additional sensor support, increasing complexity and cost.

[0077] For refrigerators, frequent door openings allow more moisture to enter, accelerating the frost buildup process. Therefore, the rate of frost formation can be estimated by counting the number of door openings and closings, and the defrosting cycle can be adjusted accordingly. This directly correlates user behavior with frost rate, making defrosting more closely aligned with actual needs. However, this method only applies to refrigerators and other devices with a defined door opening mechanism and cannot be used as a sole criterion; it needs to be used in conjunction with other factors.

[0078] Comprehensive defrosting control combines these factors into an algorithm to determine the optimal defrosting time. For example, some refrigerators consider factors such as compressor running time, ambient temperature, humidity, and the number of times the door is opened and closed, using built-in logic or artificial intelligence algorithms to make intelligent decisions.

[0079] like Figure 1 As shown, in some embodiments, when the refrigeration equipment is in a refrigeration state, the number of times the door is opened and closed and the cumulative working time of the compressor are recorded. The ambient temperature is detected by an ambient temperature sensor, and preset conditions are set. The preset conditions can be an ambient temperature threshold, a door opening and closing number threshold, a compressor cumulative working time threshold, etc. If the threshold is exceeded, refrigeration is stopped, and the heater is controlled to start and continue heating. If the temperature detected by the defrost sensor reaches the preset temperature, the heater is controlled to stop running and wait for defrosting. If the threshold is not exceeded, the number of door opening and closing and the compressor cumulative working time are obtained again.

[0080] In summary, relying on preset conditions, such as ambient temperature, cumulative compressor running time, and number of door openings and closings, to infer the degree of frost on the evaporator and arrange the defrosting cycle accordingly has certain limitations, because it is impossible to accurately determine the actual frost situation.

[0081] When only part of the refrigerator's finned evaporator is frosted, if the defrosting process is initiated according to the fixed defrosting strategy described above, the defrosting heater will require energy to melt the frost layer, even when it is not needed. Unnecessary defrosting consumes extra electricity. Furthermore, after each defrosting, the set cooling temperature needs to be re-established, which prolongs the freezing and refrigeration time. Overuse of the defrosting heater and other components may cause these parts to wear out faster, thereby shortening their lifespan and increasing energy consumption.

[0082] To address the aforementioned issues, some embodiments of this application provide a defrosting control method. This method calculates the temperature difference in the return gas pipe and then dynamically adjusts the defrosting command based on changes in the temperature difference in the return gas pipe. This allows for a more accurate assessment of the frosting condition of the finned evaporator, reducing unnecessary defrosting cycles and lowering energy consumption.

[0083] like Figure 2 As shown, the method includes the following steps:

[0084] S100: Preset defrosting conditions.

[0085] In this embodiment, defrosting conditions are first preset, and then further judgments are made based on these conditions. Defrosting conditions refer to a set of parameters or logic rules pre-set in the control system of the refrigeration equipment. When these conditions are met, the control system can start the defrosting program. However, in this embodiment, if the defrosting conditions are met, other parameters are further judged instead of directly starting the defrosting program. The defrosting conditions include at least the ambient temperature, the cumulative operating time of the compressor, and the number of times the door has been opened and closed.

[0086] Ambient temperature refers to the temperature of the air in the environment where the refrigeration equipment is located. It can be measured by a temperature sensor installed inside or outside the equipment. Ambient temperature affects the workload of the refrigeration equipment and the frosting speed on the evaporator. Lower ambient temperatures will lead to faster frosting, while higher temperatures may slow down the frosting process.

[0087] Ambient temperature is part of the defrosting conditions, and the defrosting frequency can be adjusted based on the current ambient temperature. For example, in cold seasons, even if the compressor runs for a shorter period of time, more frequent defrosting may be required.

[0088] The compressor's cumulative running time is the total duration of continuous operation since the last defrost, which can be recorded by a built-in timer and stored in the equipment control system. Compressor running time is related to the accumulation of cold energy on the evaporator surface; a longer running time means more cold energy is transferred to the evaporator, increasing the likelihood of frosting.

[0089] The thickness of the frost layer that may form on the evaporator can be predicted based on the cumulative operating time of the compressor, and the defrosting cycle can be set accordingly. If the compressor has been running for an extended period, defrosting may be triggered even if other conditions are not met.

[0090] In refrigeration equipment, for refrigerators, the number of door openings and closings refers to the number of times the refrigerator door is opened and closed within a certain period of time, which can be calculated by a switch sensor or infrared sensor installed on the door. Every time the user opens the door, outside moisture enters the refrigerator, increasing the risk of frost buildup on the evaporator. Frequent door opening and closing can accelerate frost formation.

[0091] The defrosting strategy can be dynamically adjusted based on the number of door openings and closings. If a large number of door opening and closing events are detected in a short period of time, defrosting can be started in advance to prevent excessive frost accumulation, even if the compressor running time and ambient temperature have not reached the preset threshold.

[0092] S200: If the defrosting conditions are met, calculate the temperature difference of the first return gas pipe.

[0093] In this embodiment, the defrosting condition can be met simultaneously by ambient temperature, compressor cumulative running time, and number of door openings and closings, or by a single condition. For example, when the ambient temperature is greater than the ambient temperature threshold, the temperature difference of the first return gas pipe is calculated; or when the ambient temperature is greater than the ambient temperature threshold, the compressor cumulative running time is greater than the time threshold, and the number of door openings and closings is greater than the number threshold, the temperature difference of the first return gas pipe is calculated. No limitation is imposed here.

[0094] In some embodiments, ambient temperature, cumulative compressor running time, and number of door openings and closings are acquired;

[0095] If the ambient temperature is greater than the ambient temperature threshold, or the cumulative running time of the compressor is greater than the time threshold, or the number of door openings and closings is greater than the number threshold, obtain the average temperature of the return gas pipe.

[0096] Calculate the average value of the ambient temperature and match the return air temperature based on the average value;

[0097] The temperature difference of the first return gas pipe is calculated by using the average temperature of the return gas pipe and the return gas temperature.

[0098] The ambient temperature threshold is a preset temperature threshold used to determine whether the current ambient temperature is low enough to potentially cause evaporator frosting. The ambient temperature threshold serves as the condition for triggering the acquisition of the average temperature of the return pipe. Frosting is only further confirmed when the ambient temperature is low, for example, when the ambient temperature is below the ambient temperature threshold. By setting the ambient temperature threshold, the risk of frosting in low-temperature environments can be responded to more accurately, avoiding unnecessary defrosting operations.

[0099] The time threshold is a preset time limit, representing the time after which the compressor may continuously operate for a sufficient amount of time to form a sufficient frost layer on the evaporator. The time threshold serves as the condition for triggering the acquisition of the average temperature of the return line. Further evaluation of frost formation is only considered after the compressor has been running for an extended period, such as when the cumulative compressor operating time exceeds the time threshold. By clearly defining the limits of compressor operating time, it is helpful to accurately predict frost formation caused by prolonged cooling, thereby initiating the defrosting procedure in a timely manner.

[0100] The number of times threshold is a preset limit on the number of times the door is opened, representing the degree to which frequent opening of the refrigerator door may cause rapid frost formation on the evaporator. The number of times threshold serves as a condition for triggering the acquisition of the average temperature of the return pipe. Only after the door is frequently opened and closed in a short period of time will further evaluation of the frost situation be considered. For example, if the number of door openings exceeds the number of times threshold, by setting the number of times door opening is possible to adapt to user habits and promptly address the frost problem caused by frequent door opening.

[0101] The return pipe is a pipe that connects the finned evaporator and the compressor, and is used to bring the refrigerant that has absorbed heat and evaporated into gas in the finned evaporator back to the compressor.

[0102] When the evaporator pipes and fins are covered with frost or ice, the heat exchange will decrease, the amount of liquid refrigerant (i.e., the amount of refrigerant evaporating will decrease, and the amount of liquid refrigerant returning to the compressor will increase, resulting in a decrease in the temperature of the return gas pipe. The return gas temperature will also change accordingly depending on the proportion of frost on the finned evaporator.

[0103] During the refrigeration process, after the compressor is turned on for a preset time, the average temperature of the return pipe is obtained. The preset time can be 10 minutes, that is, the average temperature Tc of the return pipe is obtained every 10 minutes, and then the average temperature Th of the ambient temperature is calculated.

[0104] The return gas temperature is matched according to the average ambient temperature. This return gas temperature is the return gas temperature when the refrigeration equipment is under light load. The return gas temperature includes a first return gas temperature, a second return gas temperature, and a third return gas temperature. In some embodiments, if the average value is less than or equal to the first temperature, the first return gas temperature is matched. The first return gas temperature is the difference between the average temperature of the return gas pipe and a first preset value.

[0105] If the average value is greater than the first temperature and less than or equal to the second temperature, a second return gas temperature is matched. The second return gas temperature is the difference between the average temperature of the return gas pipe and a second preset value, and the second preset value is greater than the first preset value.

[0106] If the average value is greater than the second temperature, a third return gas temperature is matched. The third return gas temperature is the difference between the average temperature of the return gas pipe and a third preset value, and the third preset value is greater than the second preset value.

[0107] The first temperature is 28℃, the first preset value is 1.5, the second temperature is 35℃, the second preset value is 2, and the third preset value is 2.5.

[0108] The average ambient temperature can be further differentiated to better match the return gas temperature, as shown in the table below:

[0109]

[0110] For example, if the average temperature is 25°C, then the second return gas temperature is 23°C.

[0111] After matching the return gas temperature, the first return gas pipe temperature difference ΔT is calculated. The first return gas pipe temperature difference is the difference between the average temperature of the return gas pipe and the return gas temperature before the defrosting condition is reached. During the refrigeration process, after the compressor is turned on for 10 minutes, the average temperature of the return gas pipe is obtained every 10 minutes. By matching the return gas temperature, the first return gas pipe temperature difference can be calculated.

[0112] The first return pipe temperature difference refers to the difference between the average temperature of the return pipe and the current return pipe temperature. The refrigerant in the return pipe has just absorbed heat from the evaporator and flowed out. Therefore, its temperature directly reflects the working state of the evaporator. Since the return pipe temperature difference is closely related to the actual performance of the evaporator, it can provide the most direct and accurate information about the degree of frost on the evaporator.

[0113] When the evaporator begins to frost, heat exchange efficiency decreases, causing the return gas temperature to drop. This change can be detected by the temperature difference in the return gas line. Other temperature differences, such as the difference between ambient temperature and set temperature, may be affected by more external factors.

[0114] Furthermore, the return pipe is located inside the refrigeration system, which is relatively enclosed and less affected by the external environment. This means that the measurement results are more stable and reliable, and less susceptible to interference from factors such as room temperature fluctuations and the number of times the door is opened. For example, if the ambient temperature is used as a reference point, the temperature reading may fluctuate due to user behavior or seasonal changes, thus affecting the accuracy of the judgment.

[0115] As the frost layer thickens, the heat exchange efficiency of the evaporator gradually decreases, and the return gas temperature also drops accordingly. By monitoring the changing trend of the temperature difference in the return gas pipe, the degree of frost formation can be assessed relatively accurately. Other types of temperature differences may not reflect this change process in such detail, especially when the frost layer has just begun to form, the change may not be obvious.

[0116] S300: If the temperature difference of the first return gas pipe is less than the first temperature difference threshold and greater than or equal to the second temperature difference threshold, execute the first defrosting command.

[0117] The first temperature difference threshold is 0℃, and the second temperature difference threshold is -0.5℃. In some embodiments, if the temperature difference of the first return pipe is greater than or equal to the first temperature difference threshold, the defrosting command is not executed. When the temperature difference of the first return pipe is large, the heat exchange efficiency of the evaporator is still high, and sufficient frost may not form to significantly affect the cooling effect. By setting a higher first temperature difference threshold, it can be ensured that the defrosting program is only activated when truly needed, avoiding frequent defrosting due to slight frost formation, thereby reducing energy waste.

[0118] Frequent defrosting operations can place an additional burden on the compressor and other components, increasing the risk of mechanical stress or electrical failure. By setting reasonable defrosting trigger conditions—that is, only performing defrosting when the temperature difference in the return gas line is less than a specific threshold—the equipment can be effectively protected and its service life extended.

[0119] like Figure 3 As shown, in some embodiments, if the temperature difference of the first return gas pipe is less than the first temperature difference threshold and greater than or equal to the second temperature difference threshold, a first preset number of second return gas pipe temperatures are obtained, wherein the second return gas pipe temperature difference is the return gas pipe temperature difference obtained after obtaining the first return gas pipe temperature difference.

[0120] If a preset proportion of the second return gas pipe temperature difference in the first preset quantity is less than the first temperature difference threshold, but greater than or equal to the second temperature difference threshold, the first defrosting instruction is set to execute defrosting after the defrosting interval time is increased by the first time.

[0121] If a preset proportion of the second return gas pipe temperature difference in the first preset quantity is less than the second temperature difference threshold and greater than or equal to the third temperature difference threshold, execute the second defrosting command.

[0122] If the temperature difference of the second return gas pipe in the first preset quantity is less than the third temperature difference threshold, execute the third defrosting command.

[0123] For the second return airway temperature difference, the decision to immediately perform defrosting is made by observing the trend over a future period. When the first return airway temperature difference is in a relatively mild range (less than the first temperature difference threshold and greater than or equal to the second temperature difference threshold), it is necessary to further confirm whether the frosting situation will continue to worsen. Therefore, new temperature difference data, i.e., the second return airway temperature difference, is continuously collected over the next period to determine whether there is sufficient evidence to support immediate defrosting.

[0124] Unnecessary defrosting operations can be delayed without affecting the cooling effect, saving energy. By dynamically monitoring subsequent changes, the defrosting strategy can be adjusted more flexibly to ensure that the defrosting program is only activated when needed.

[0125] In this embodiment, the first temperature difference threshold is 0℃, the second temperature difference threshold is -0.5℃, the third temperature difference threshold is -1℃, the first preset quantity is the number of continuously acquired return gas pipe temperature differences, the first preset quantity can be 3, the preset ratio is two-thirds, and the first time is 6h.

[0126] It is understandable that the temperature difference ΔT2 of the second return gas pipe of the first preset number can be multiple values, and the three ΔT2 can be ΔT... 21 ΔT 22 ΔT 23For a preset ratio where the temperature difference in the second return gas pipe is less than the first temperature difference threshold but greater than or equal to the second temperature difference threshold, several cases can be identified, such as -0.5℃ < ΔT. 21 ≤0℃ and -0.5℃<ΔT 22 ≤0℃; for example, -0.5℃<ΔT 21 ≤0℃ and -0.5℃<ΔT 23 ≤0℃; for example, -0.5℃<ΔT 22 ≤0℃ and -0.5℃<ΔT 23 ≤0℃. For other elements in this embodiment that have preset ratios, please refer to this example; the principle is the same.

[0127] The first temperature difference threshold is the upper limit of the temperature difference in the return pipe. When the temperature difference in the return pipe is greater than or equal to the first temperature difference threshold, the defrosting command is not executed, ensuring that the defrosting program is only started when defrosting is truly necessary, thus avoiding unnecessary energy waste.

[0128] The second temperature difference threshold is an intermediate threshold between the first and third temperature difference thresholds, used to distinguish different degrees of frost and guide the system to select an appropriate defrosting strategy.

[0129] The third temperature difference threshold is the lower limit of the return pipe temperature difference. When the return pipe temperature difference is less than this value, it indicates that a thicker frost layer has formed on the evaporator, triggering a more urgent defrosting operation to prevent a significant decrease in cooling efficiency.

[0130] If the temperature difference of the first return pipe is less than 0℃ and greater than or equal to -0.5℃, the temperature difference of the second return pipe is acquired. This second return pipe temperature difference is then acquired continuously at the next three time points, forming a data set. If two or more of the second return pipe temperature differences are less than 0℃ and greater than or equal to -0.5℃ at these three time points, the first defrosting command is set to execute defrosting after the defrosting interval is increased by 6 hours. This indicates that although there is slight frost, it is not enough for immediate defrosting; therefore, the defrosting time is delayed to save energy.

[0131] If the temperature difference of the second return pipe is less than -0.5℃ and greater than or equal to -1℃ at two or more of these three time points, the second defrost command is executed. This means that there is a certain amount of frost layer, and defrosting needs to be performed in time to maintain the cooling effect. If the temperature difference of the second return pipe is less than -1℃ at two or more of these three time points, the third defrost command is executed. This indicates that a thick frost layer has formed on the evaporator, and defrosting must be performed immediately to restore the cooling performance.

[0132] The second and third defrost commands are detailed in S400 and S500.

[0133] By setting temperature difference thresholds and preset ratios, the accuracy and reliability of defrosting decisions can be improved. This not only reduces unnecessary full-cycle defrosting due to partial frost, thus reducing energy waste, but also better adapts to different usage scenarios and maintains optimal cooling performance.

[0134] S400: If the temperature difference of the first return gas pipe is less than the second temperature difference threshold and greater than or equal to the third temperature difference threshold, execute the second defrosting command.

[0135] like Figure 4 As shown, in some embodiments, if the temperature difference of the first return gas pipe is less than the second temperature difference threshold and greater than or equal to the third temperature difference threshold, a second preset number of third return gas pipe temperature differences are obtained, wherein the third return gas pipe temperature difference is the return gas pipe temperature difference before the first return gas pipe temperature difference is obtained.

[0136] The cumulative duration during which the temperature difference of the third return air pipe is less than the second temperature difference threshold is obtained (for a second preset number of times).

[0137] If the cumulative duration is less than the first duration, a second defrost command is set to add a second time to the defrost interval, where the second time is less than the first time.

[0138] The temperature difference ΔT3 of the third return pipe for the second preset number can also be 15 different values, similar to the temperature difference of the second return pipe, which will not be elaborated here.

[0139] The second preset quantity is 15, the first duration is 90 minutes, and the second time is 3 hours.

[0140] For example, the temperature difference of the first return pipe is -0.7℃, which meets the condition of being less than the second temperature difference threshold (-0.5℃) and greater than or equal to the third temperature difference threshold (-1℃). 15 third return pipe temperature differences are obtained, that is, the return pipe temperature differences before obtaining the first return pipe temperature difference. 10 of the 15 temperature differences are less than -0.5℃, with a cumulative duration of 80 minutes (less than the first duration of 90 minutes). The second defrosting command is set to execute defrosting after the defrosting interval is increased by 3 hours to adapt to the current lighter frost condition, thus saving energy and ensuring the cooling effect.

[0141] For the third return vent temperature difference, historical data is reviewed to verify whether the current frosting situation shows a persistent trend. When the first return vent temperature difference already shows a low value (less than the second temperature difference threshold and greater than or equal to the third temperature difference threshold), it is necessary to confirm whether this is a one-off fluctuation or a long-term trend. Therefore, by obtaining temperature difference data over a period of time prior, i.e., the third return vent temperature difference, it is possible to ensure that the current low temperature difference is not a random phenomenon, which helps avoid making incorrect defrosting decisions due to short-term fluctuations and improves the reliability of defrosting instructions. At the same time, by analyzing historical data, future frosting trends can be predicted more accurately, thereby optimizing the defrosting interval.

[0142] In this embodiment, the second defrosting command can be either to increase the defrosting interval or to execute defrosting immediately. If a preset proportion of the second return gas pipe temperature difference in the first preset quantity is less than the second temperature difference threshold and greater than or equal to the third temperature difference threshold, the cumulative duration can be further determined to ascertain the specific content of the second defrosting command.

[0143] In some embodiments, if the cumulative duration is greater than or equal to the first duration and less than the second duration, the cumulative duration for which the temperature difference of the third return air pipe is less than the second temperature difference threshold is obtained for a first preset number of such durations.

[0144] If the cumulative duration is greater than or equal to the second duration, calculate the defrosting time, where the defrosting time is the time since the last defrosting was completed.

[0145] If the defrosting time is greater than or equal to the first time, the second defrosting command is set to execute defrosting.

[0146] The second duration is 120 minutes. For example, the first return pipe temperature difference is -0.7℃, which meets the condition of being less than -0.5℃ and greater than or equal to -1℃. The system then reviews 15 third return pipe temperature differences, i.e., the return pipe temperature differences before acquiring the first return pipe temperature difference. Of these 15 temperature differences, 12 are less than -0.5℃, with a cumulative duration of 110 minutes (greater than the first duration of 90 minutes and less than the second duration of 120 minutes). The system continues to acquire the cumulative duration of 15 third return pipe temperature differences. If this cumulative duration reaches or exceeds 120 minutes, the defrosting time is calculated. If the defrosting time exceeds 6 hours, the second defrosting command is set to execute defrosting immediately to ensure timely removal of frost and restoration of cooling performance.

[0147] S500: If the temperature difference of the first return gas pipe is less than the third temperature difference threshold, execute the third defrosting command.

[0148] The third instruction is to immediately perform defrosting. If the temperature difference of the second return air pipe in the first preset quantity is less than the third temperature difference threshold, defrosting can be performed immediately.

[0149] In some embodiments, if the temperature difference of the first return pipe is less than the third temperature difference threshold, the temperature difference of the fourth return pipe is obtained, and the temperature difference of the fourth return pipe is the return pipe temperature difference before the first return pipe temperature difference is obtained.

[0150] If a preset proportion of the fourth return air pipe temperature difference in the first preset quantity is less than the third temperature difference threshold, the defrosting time is calculated, where the defrosting time is the time since the last defrosting was completed.

[0151] If the defrosting time is greater than or equal to the first time, the third defrosting command is set to execute defrosting.

[0152] For example, the temperature difference of the first return pipe is -1.2℃, which meets the condition of being less than -1℃. Reviewing the temperature differences of the previous three fourth return pipes, two of these three temperature differences are less than -1℃, which meets the preset ratio. The defrosting time, i.e., the time since the last defrosting was completed, is calculated, and the result is 7 hours. Based on the above results, the third defrosting command is set to execute defrosting immediately to ensure timely removal of frost and restoration of cooling performance.

[0153] When the temperature difference of the first return pipe is significantly lower than the third temperature difference threshold, it indicates that the frost layer on the evaporator is already quite thick, affecting heat exchange efficiency. In this case, continuing to collect a large amount of historical data, such as 15 times, may not be necessary, because the current low temperature difference already indicates a serious frosting problem. By only acquiring the temperature difference of the fourth return pipe from the first three times, it is possible to confirm whether the frosting trend continues, thus making a defrosting decision more quickly and avoiding affecting the cooling effect due to delays.

[0154] In some embodiments, the method further includes:

[0155] If the temperature difference of the fourth return air pipe in the first preset quantity is greater than or equal to the third temperature difference threshold and less than the second temperature difference threshold, execute the second defrosting command.

[0156] If there is no fourth return pipe temperature difference less than the third temperature difference threshold in the first preset quantity, or if there is no fourth return pipe temperature difference greater than or equal to the third temperature difference threshold in the first preset quantity and less than the second temperature difference threshold, the fifth return pipe temperature difference of the third preset quantity is obtained. The fifth return pipe temperature difference is the return pipe temperature difference obtained after obtaining the first return pipe temperature difference.

[0157] Based on the fifth return pipe temperature difference of a third preset number, the sixth return pipe temperature difference of a first preset number is obtained, so as to obtain a defrosting command through the sixth return pipe temperature difference. The sixth return pipe temperature difference is the return pipe temperature difference obtained after obtaining the fifth return pipe temperature difference. The defrosting command includes a first defrosting command, a second defrosting command, and a third defrosting command.

[0158] If two-thirds of the fourth return pipes in the first preset quantity have a temperature difference of less than -1℃, calculate the defrosting time. If the defrosting time is greater than or equal to 6 hours, set the third defrosting command to execute defrosting immediately. This indicates that the frosting situation is relatively serious and defrosting needs to be performed immediately to restore the cooling performance.

[0159] If, for example, two-thirds of the fourth return gas pipes in the first preset quantity have a temperature difference greater than or equal to -1℃ and less than -0.5℃, execute the second defrosting command. This indicates that the frosting situation is relatively mild and a lighter defrosting measure is required to avoid starting defrosting too early and to save energy.

[0160] The third preset quantity is 2. For the fourth return gas pipe temperature difference ΔT4, there are three situations. The first situation is that ΔT4 < -1℃ for any two times, and the defrosting command is executed immediately after the time since the last defrosting is ≥ 6h. The second situation is that -1℃ ≤ ΔT < -0.5℃ for any two times, and the judgment is continued by S400. If the first and second situations are not met, the third situation is adopted, and the return gas pipe temperature difference is monitored for two more times, which is the fifth return gas pipe temperature difference.

[0161] Combining these two return pipe temperature differences, the final three return pipe temperature differences, i.e., the sixth return pipe temperature difference, are obtained. A defrosting command is then generated based on these final three return pipe temperature differences. For example, if any two temperature differences between the last three return pipe temperature differences are less than or equal to 1°C and the sixth return pipe temperature difference is less than -0.5°C, the S400 system continues to make a judgment. This ensures that defrosting control is based on the latest data, improving the flexibility and accuracy of decision-making and avoiding incorrect defrosting decisions due to short-term fluctuations.

[0162] Based on the above-described defrosting control method, some embodiments of this application also provide a refrigeration device, including:

[0163] The control unit is configured to preset defrost conditions;

[0164] The temperature acquisition module is configured to calculate the first return gas pipe temperature difference if the defrosting conditions are met. The first return gas pipe temperature difference is the difference between the average temperature of the return gas pipe and the return gas temperature before the defrosting conditions are met.

[0165] The control unit is also configured to:

[0166] If the temperature difference of the first return gas pipe is less than the first temperature difference threshold and greater than or equal to the second temperature difference threshold, execute the first defrosting command;

[0167] If the temperature difference of the first return gas pipe is less than the second temperature difference threshold and greater than or equal to the third temperature difference threshold, execute the second defrosting command;

[0168] If the temperature difference of the first return gas pipe is less than the third temperature difference threshold, execute the third defrosting command.

[0169] The refrigeration equipment provided in this application embodiment can be a refrigerator, air conditioner, etc. Taking a refrigerator as an example, to achieve refrigeration and operation, it includes at least a refrigeration system, a cooling system, a control system, and a cabinet. The refrigeration system is used to generate a refrigeration effect, the cooling system is used to maintain a low-temperature environment, the control system is used to control the temperature and humidity inside the refrigerator, and the cabinet is used to provide storage space. It is understood that the refrigeration system, cooling system, and control system include specific components capable of achieving the above functions.

[0170] In some embodiments, the refrigeration system includes a compressor, a condenser, an evaporator, and a throttling device. The compressor compresses the refrigerant gas, increasing its pressure and temperature, thereby propelling the refrigerant through the system. During compression, the refrigerant changes from a low-pressure, high-temperature gas to a high-pressure, high-temperature gas, thus producing a cooling effect. The condenser cools the high-temperature, high-pressure gas discharged from the compressor into a liquid state. Heat is released through heat sinks, and the refrigerant gas transforms into a liquid state, ready to enter the next step of the refrigeration cycle. The evaporator absorbs heat in the refrigeration system. The refrigerant evaporates from a liquid state to a gaseous state in the evaporator, absorbing heat from the surrounding environment, thereby lowering the internal temperature of the refrigerator. The throttling device may include an expansion valve and a capillary tube, used to regulate the refrigerant flow rate and reduce its pressure, making it a low-temperature, low-pressure gas-liquid mixture, ready to enter the evaporator.

[0171] In some embodiments, the cooling system includes a fan connected to the evaporator. The fan circulates air within compartments, such as the freezer and refrigerator compartments, transferring heat to the evaporator to help maintain a low-temperature environment inside the refrigerator.

[0172] It should be noted that the above examples are merely a simple division of refrigerator functions and do not limit the specific structural configuration of the refrigerator in the embodiments of this application.

[0173] 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 characterized by, The method comprises: a preset defrosting condition; if the defrosting condition is reached, calculating a first return air pipe temperature difference, the first return air pipe temperature difference being a difference between a return air pipe average temperature before the defrosting condition is reached and a return air temperature; if the first return air pipe temperature difference is less than a first temperature difference threshold and greater than or equal to a second temperature difference threshold, executing a first defrosting instruction; if the first return air pipe temperature difference is less than the second temperature difference threshold and greater than or equal to a third temperature difference threshold, executing a second defrosting instruction; if the first return air pipe temperature difference is less than the third temperature difference threshold, executing a third defrosting instruction; the defrosting condition at least comprises an ambient temperature, a compressor cumulative running time and a door opening and closing frequency; if the first return air pipe temperature difference is less than the first temperature difference threshold and greater than or equal to the second temperature difference threshold, the first defrosting instruction is executed, which comprises: if the first return air pipe temperature difference is less than the first temperature difference threshold and greater than or equal to the second temperature difference threshold, a first preset number of second return air pipe temperature differences is obtained, the second return air pipe temperature difference being a return air pipe temperature difference obtained after the first return air pipe temperature difference is obtained; if a preset proportion of the second return air pipe temperature differences in the first preset number is less than the first temperature difference threshold and greater than or equal to the second temperature difference threshold, the first defrosting instruction is set to execute defrosting after a first time interval is increased by a first time; if a preset proportion of the second return air pipe temperature differences in the first preset number is less than the second temperature difference threshold and greater than or equal to the third temperature difference threshold, the second defrosting instruction is executed; if a preset proportion of the second return air pipe temperature differences in the first preset number is less than the third temperature difference threshold, the third defrosting instruction is executed; if the first return air pipe temperature difference is less than the second temperature difference threshold and greater than or equal to the third temperature difference threshold, the second defrosting instruction is executed, which comprises: if the first return air pipe temperature difference is less than the second temperature difference threshold and greater than or equal to the third temperature difference threshold, a second preset number of third return air pipe temperature differences is obtained, the third return air pipe temperature difference being a return air pipe temperature difference before the first return air pipe temperature difference is obtained; an accumulated time length of the third return air pipe temperature differences in the second preset number being less than the second temperature difference threshold is obtained; if the accumulated time length is less than a first time length, the second defrosting instruction is set to increase a second time interval by a second time, the second time being less than the first time; if the first return air pipe temperature difference is less than the third temperature difference threshold, the third defrosting instruction is executed, which comprises: if the first return air pipe temperature difference is less than the third temperature difference threshold, a fourth return air pipe temperature difference is obtained, the fourth return air pipe temperature difference being a return air pipe temperature difference before the first return air pipe temperature difference is obtained; if a preset proportion of the fourth return air pipe temperature differences in the first preset number is less than the third temperature difference threshold, a defrosting time is calculated, the defrosting time being a time from completion of last defrosting; if the defrosting time is greater than or equal to the first time, the third defrosting instruction is set to execute defrosting.

2. The defrosting control method according to claim 1, wherein if the defrosting condition is reached, the first return air pipe temperature difference is calculated, which comprises: the ambient temperature, the compressor cumulative running time and the door opening and closing frequency are obtained; if the ambient temperature is less than an ambient temperature threshold, or, a compressor cumulative running time is greater than a time threshold, or, a door opening times is greater than a times threshold, obtaining a return air pipe average temperature; calculating an average value of the ambient temperature, and matching a return air temperature based on the average value; calculating a first return air pipe temperature difference by the return air pipe average temperature and the return air temperature.

3. The defrosting control method according to claim 2, characterized by, The matching the return air temperature based on the average value comprises: if the average value is less than or equal to a first temperature, matching a first return air temperature, the first return air temperature being a difference between the return air pipe average temperature and a first preset value; if the average value is greater than the first temperature and less than or equal to a second temperature, matching a second return air temperature, the second return air temperature being a difference between the return air pipe average temperature and a second preset value, the second preset value being greater than the first preset value; if the average value is greater than the second temperature, matching a third return air temperature, the third return air temperature being a difference between the return air pipe average temperature and a third preset value, the third preset value being greater than the second preset value.

4. The defrosting control method according to claim 1, characterized by, The executing the second defrosting instruction if the first return air pipe temperature difference is less than a second temperature difference threshold and greater than or equal to a third temperature difference threshold further comprises: if the cumulative duration is greater than or equal to a first duration and less than a second duration, obtaining a first preset number of cumulative durations of the third return air pipe temperature difference being less than the second temperature difference threshold; if the cumulative duration is greater than or equal to the second duration, calculating a defrosting time, the defrosting time being a time from a last defrosting completion; if the defrosting time is greater than or equal to a first time, setting the second defrosting instruction as executing defrosting.

5. The defrosting control method according to claim 1, wherein The method further comprises: if a preset proportion of the fourth return air pipe temperature difference in the first preset number is greater than or equal to the third temperature difference threshold and less than the second temperature difference threshold, executing the second defrosting instruction; if a preset proportion of the fourth return air pipe temperature difference in the first preset number is less than the third temperature difference threshold, or a preset proportion of the fourth return air pipe temperature difference in the first preset number is greater than or equal to the third temperature difference threshold and less than the second temperature difference threshold, obtaining a third preset number of fifth return air pipe temperature differences, the fifth return air pipe temperature difference being a return air pipe temperature difference obtained after obtaining the first return air pipe temperature difference; obtaining a first preset number of sixth return air pipe temperature differences based on the third preset number of the fifth return air pipe temperature differences, to obtain a defrosting instruction by the sixth return air pipe temperature difference, the sixth return air pipe temperature difference being a return air pipe temperature difference obtained after obtaining the fifth return air pipe temperature difference, the defrosting instruction comprising a first defrosting instruction, a second defrosting instruction and a third defrosting instruction.

6. The defrosting control method according to claim 1, characterized by, The method further comprises: if the first return air pipe temperature difference is greater than or equal to a first temperature difference threshold, not executing the defrosting instruction.

7. A refrigeration appliance characterized in that, The refrigeration equipment is configured with the defrosting control method of claim 1, and the refrigeration equipment comprises: a control unit configured to preset a defrosting condition; a temperature acquisition module configured to calculate a first return air pipe temperature difference if the defrosting condition is reached, the first return air pipe temperature difference being a difference between a return air pipe average temperature before the defrosting condition is reached and a return air temperature; the control unit is further configured to: if the first return gas pipe temperature difference is less than a first temperature difference threshold value and greater than or equal to a second temperature difference threshold value, a first defrosting instruction is executed; if the first return gas pipe temperature difference is less than the second temperature difference threshold value and greater than or equal to a third temperature difference threshold value, a second defrosting instruction is executed; if the first return gas pipe temperature difference is less than the third temperature difference threshold value, a third defrosting instruction is executed.

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