Refrigerator and control method thereof

Abstract

This invention discloses a refrigerator and its control method. The refrigerator includes: a front cover plate of the air duct, a rear cover plate of the air duct, a refrigerator liner, a refrigeration circuit, a first fan, a first temperature sensor, a defrost heater, a second fan, and a controller. The controller is configured to: acquire the temperature of the storage compartment when the defrost heater is turned on; determine the temperature change of the storage compartment based on the temperature of the storage compartment; and control the second fan to turn on when the determined temperature change reaches the condition used to indicate that the temperature of the storage compartment is rising too quickly. This allows for precise control of the timing of the second fan's activation based on the temperature of the storage compartment during the defrosting process, thereby effectively preventing hot air from escaping into the storage compartment during defrosting and solving the problem of temperature rise in the storage compartment caused by defrosting.

Description

Technical Field

[0001] This invention relates to the field of refrigerator technology, and in particular to a refrigerator and its control method. Background Technology

[0002] In related technologies, to prevent heat from spreading from the evaporator compartment to the storage compartment during defrosting via electric heating in the refrigerator, some solutions add a fan lifting mechanism or air outlet baffle at the freezer compartment air duct to physically block the outflow of hot air. While this method can suppress temperature rise, it is structurally complex, costly, easily affects the cooling airflow, and has insufficient long-term reliability; moreover, completely blocking the air inlet will hinder the circulation of hot air into the air duct, causing residual moisture to freeze. Another type of solution uses a reverse-rotating cooling fan to blow hot air back to the evaporator compartment, but its reversal timing depends only on the evaporator temperature and does not take into account the freezer compartment temperature, making it difficult to match the actual heat migration requirements, resulting in insufficient control precision for the fan's entry and exit timing. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, the object of the present invention is to provide a refrigerator.

[0004] The present invention provides a refrigerator comprising: The refrigerator includes a front cover plate, a rear cover plate, and an inner liner. The front cover plate and the rear cover plate form an air duct. The rear cover plate and the inner liner form an evaporator compartment. The rear cover plate has an air inlet. A refrigeration circuit, comprising a compressor, an evaporator, a throttling device, and a condenser, wherein the evaporator is located in the evaporator compartment; A first fan is located in the air duct and is disposed at the air inlet. It is used to rotate in a first rotation direction in the cooling mode to transfer the cooling capacity of the evaporator to the storage room through the air inlet and the air duct. The first temperature sensor is used to detect the temperature of the storage room. A defrosting heater, located inside the evaporator compartment, is used to heat and defrost the evaporator when it is turned on; The second fan is located in the evaporator compartment and is disposed at the air inlet. When turned on, it rotates in a second rotation direction opposite to the first rotation direction to prevent hot air from the evaporator compartment from entering the air duct through the air inlet. The controller is configured to: The temperature of the storage compartment is obtained when the defrosting heater is turned on; The temperature change of the storage room is determined based on the temperature of the storage room. When it is determined that the temperature change reaches the condition used to indicate that the storage room is heating up too quickly, the second fan is controlled to start.

[0005] According to an embodiment of the present invention, the refrigerator obtains the temperature of the storage compartment when the defrost heater is turned on, determines the temperature change of the storage compartment based on the evaporator temperature, and then determines whether the condition of excessively rapid temperature rise in the storage compartment has been met based on the temperature change. After determining that the condition of excessively rapid temperature rise in the storage compartment has been met, the second fan is controlled to turn on. This allows for precise control of the timing of the second fan's activation based on the storage compartment temperature during the defrosting process, thereby effectively preventing hot air from escaping into the storage compartment during defrosting and solving the problem of temperature rise in the storage compartment caused by defrosting.

[0006] In addition, the refrigerator according to embodiments of the present invention may also have the following additional technical features: Furthermore, the controller is configured to: when the temperature change exceeds a first preset temperature threshold, confirm that the conditions for indicating that the storage room is heating up too quickly have been met.

[0007] The above-mentioned technical solution has the following advantages or beneficial effects: it can form a directional airflow barrier at the air outlet or air inlet, effectively blocking the backflow of hot air, thereby promptly suppressing further increases in the storage room temperature and ensuring the quality of food storage. This judgment mechanism is based on the actual temperature rise dynamics of the storage room, responding promptly and logically, avoiding the lag or misjudgment caused by relying solely on evaporator-side parameters, and achieving precise control over the timing of the second fan's intervention.

[0008] Furthermore, the controller is configured to determine the temperature change based on a first temperature difference between the storage room temperature sampled at the current sampling time and the storage room temperature sampled at the previous sampling time.

[0009] The above technical solution has the following advantages or beneficial effects: it can more sensitively reflect whether hot air has begun to invade the storage room, thereby providing a basis for the precise entry of the second fan and improving the accuracy of determining the entry timing of the second fan.

[0010] Furthermore, when controlling the second fan to start, the controller is configured to control the second fan to operate at a constant speed of a first preset speed.

[0011] The above technical solution has the following advantages or beneficial effects: it not only simplifies the control logic and improves the reliability of system operation, but also achieves a balance between rapid response and energy-saving operation while ensuring the thermal barrier effect.

[0012] Furthermore, when controlling the second fan to start, the controller is configured to dynamically control the speed of the second fan according to a preset speed control strategy.

[0013] The above technical solution has the following advantages or beneficial effects: it enables the rotation speed of the second fan to adapt to the heat changes in the air duct, matching the heat changes in the air duct, and achieving more precise control of the heat circulation in the evaporator chamber. This not only improves defrosting efficiency but also effectively prevents hot air from entering the storage room through the air outlet.

[0014] Furthermore, the refrigerator also includes a second temperature sensor for detecting the evaporator temperature; the preset speed control strategy includes: the second fan starts operating at a second preset speed, and after starting operation, the speed of the second fan is calculated in real time through a preset speed algorithm; wherein, the speed algorithm includes a calculation relationship for calculating the speed of the second fan based on the current evaporator temperature, and the evaporator temperature is directly proportional to the speed of the second fan; or, the speed algorithm includes a calculation relationship for calculating the speed of the second fan based on a second temperature difference and the heating time of the defrost heater, and the speed of the second fan is directly proportional to the second temperature difference and / or the heating time, wherein the second temperature difference is the temperature difference between the evaporator temperature sampled at the current sampling time and the storage compartment temperature sampled at the current sampling time; or, the speed algorithm includes a calculation relationship for calculating the speed of the second fan based on the second preset speed and the operating time of the second fan, and the speed of the second fan is directly proportional to the operating time.

[0015] The above technical solution has the following advantages or beneficial effects: it enables the rotation speed of the second fan to adapt to the heat changes in the air duct, matching the heat changes in the air duct, and achieving more precise control of the heat circulation in the evaporator chamber. This not only improves defrosting efficiency but also effectively prevents hot air from entering the storage room through the air outlet.

[0016] Furthermore, the refrigerator also includes a second temperature sensor for detecting the evaporator temperature; after controlling the second fan to turn on, the controller is further configured to: when it is determined that the conditions for the second fan to turn off are met, control the second fan to turn off, wherein the conditions for the second fan to turn off include: after the defrost heater stops operating, a third temperature difference between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time is less than or equal to a second preset temperature threshold; or, after the defrost heater stops operating, the evaporator temperature is greater than or equal to a third preset temperature threshold, wherein the third preset temperature threshold is greater than or equal to the second preset temperature threshold; or, a fourth temperature difference is less than a fifth temperature difference, wherein the fourth temperature difference is the temperature difference between the storage compartment temperature sampled at the current sampling time and the storage compartment temperature sampled at the previous sampling time, and the fifth temperature difference is the temperature difference between the storage compartment temperature sampled at the previous sampling time and the storage compartment temperature sampled at the time before that.

[0017] The above technical solution has the following advantages or beneficial effects: improving the accuracy of the timing of the second fan cut-out, and achieving energy-saving optimization while ensuring temperature control.

[0018] Furthermore, before the defrost heater is turned on, the controller is also configured to: control the refrigerator to stop in response to a defrost command; and control the defrost heater to turn on when the evaporator temperature reaches a fourth preset temperature threshold, or when the shutdown time reaches a preset time.

[0019] The above technical solution has the following advantages or beneficial effects: it can take into account the accuracy of defrosting and ensure that the defrosting process is started in a timely manner under safe and controllable conditions.

[0020] Furthermore, the rated operating power of the second fan is less than that of the first fan.

[0021] The above-mentioned technical solution has the following advantages or beneficial effects: it not only effectively reduces the additional energy consumption during the defrosting stage, but also reduces noise generation and avoids interference with the natural heat convection in the evaporator compartment or affecting the subsequent cooling recovery process due to excessive air volume. Thus, while ensuring the defrosting thermal management effect, it also takes into account the overall energy efficiency, quietness and system stability.

[0022] To address the aforementioned problems, the present invention also proposes a control method for the refrigerator, comprising: acquiring the temperature of the storage compartment when the defrosting heater is turned on; determining the temperature change of the storage compartment based on the temperature of the storage compartment; and controlling the second fan to turn on when the temperature change reaches a condition indicating that the storage compartment is heating up too quickly, so as to prevent hot air from the evaporator compartment from entering the air duct through the air inlet.

[0023] According to the refrigerator control method of this invention, when the defrost heater is turned on, the temperature of the storage compartment is acquired, and the temperature change of the storage compartment is determined based on the evaporator temperature. Then, based on the temperature change, it is determined whether the condition for excessively rapid temperature rise in the storage compartment has been met. If the condition for excessively rapid temperature rise is determined, the second fan is turned on. This allows for precise control of the timing of the second fan's activation during defrosting based on the storage compartment temperature, effectively preventing hot air from escaping into the storage compartment during defrosting and solving the problem of temperature rise in the storage compartment caused by defrosting. Furthermore, based on this, the rotation speed of the second fan is dynamically adjusted in conjunction with the timing of its on / off, so that the fan speed can adapt to the heat changes within the air duct, matching the heat changes within the air duct. This achieves more precise control of heat circulation within the evaporator cavity, not only improving defrosting efficiency but also effectively preventing hot air from entering the storage compartment through the air outlet.

[0024] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0025] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of a refrigerator according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a micro fan structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of a duct assembly according to an embodiment of the present invention; Figure 4 This is a schematic diagram of a refrigerator according to an embodiment of the present invention; Figure 5 This is a block diagram of a refrigerator according to an embodiment of the present invention; Figure 6 This is a structural block diagram of a refrigerator according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the rotational speed change of a second fan according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the evaporator defrosting process according to an embodiment of the present invention; Figure 9 This is a flowchart of a refrigerator control method according to an embodiment of the present invention. Detailed Implementation

[0026] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present invention are described in detail below.

[0027] The first aspect of the present invention provides a refrigerator.

[0028] Figure 1 This is a schematic diagram of a refrigerator structure according to an embodiment of the present invention, as shown below. Figure 1 As shown, the refrigerator 100 includes: a front cover plate 01 for the air duct, a rear cover plate 02 for the air duct, and an inner liner 03.

[0029] The front cover plate 01 and the rear cover plate 02 of the air duct form an air duct. The rear cover plate 02 of the air duct and the inner liner 03 of the refrigerator form an evaporator compartment. The rear cover plate 02 of the air duct has an air inlet.

[0030] like Figure 1 The illustrated air duct includes a space constructed by a front cover plate 01 and a rear cover plate 02, as well as a refrigerator inner liner 03. The rear cover plate 02 has an air inlet, and a cooling fan 1 is installed in the air duct. A miniature fan 2 (i.e., a second fan) is installed at the air inlet of the rear cover plate 02. The miniature fan 2 is mounted on the rear cover plate 02, with its center directly aligned with the center of the air guide ring at the air inlet of the air duct. The gap between the lowest point of the blades of the miniature fan 2 and the air guide ring is 5mm. Figure 2 The diagram shows the structure of the miniature fan 2. The blades of the miniature fan 2 are fixed to the fan bracket, which has screw fixing structures on both sides. The final assembly diagram of the air duct is shown below. Figure 3 As shown.

[0031] like Figure 4 As shown, the refrigeration circuit in the refrigerator 100 includes a condenser 3, a throttling device 6, an evaporator 8, and a compressor 9, wherein the evaporator 8 is located in the evaporator compartment.

[0032] The refrigeration process of refrigerator 100 includes compression, condensation, throttling, and evaporation. The compression process is as follows: When the refrigerator power cord is plugged in and the thermostat contacts are closed, compressor 9 starts working. Low-temperature, low-pressure refrigerant is drawn into compressor 9 and compressed into high-temperature, high-pressure superheated gas in the compressor 9 cylinder before being discharged into condenser 3. The condensation process is as follows: The high-temperature, high-pressure refrigerant gas dissipates heat through condenser 3, its temperature continuously decreasing until it is gradually cooled into room-temperature, high-pressure saturated vapor, and further cooled into saturated liquid. The temperature at this point no longer decreases; this temperature is called the condensation temperature. The pressure of the refrigerant remains almost constant throughout the condensation process. The throttling process is as follows: After condensation, the saturated refrigerant liquid is filtered through the receiver to remove moisture and impurities before flowing into throttling device 6, where it is throttled and depressurized, thus achieving refrigeration. The refrigerant is converted into room temperature, low pressure wet vapor. The evaporation process is as follows: the room temperature, low pressure wet vapor begins to absorb heat and vaporize in the evaporator 8, which not only lowers the temperature of the evaporator 8 and its surroundings, but also turns the refrigerant into a low temperature, low pressure gas. The refrigerant coming out of the evaporator 8 passes through the gas-liquid separator and returns to the compressor 9. The above process is repeated to transfer the heat inside the refrigerator to the air outside the refrigerator, thus achieving the purpose of refrigeration. While the refrigerator is refrigerating, the refrigeration fan 1 forces air to flow, evenly distributing the cold air generated by the evaporator 8 to all areas of the refrigerator, avoiding uneven temperature, accelerating the heat exchange process, reducing the running time of the compressor 9, reducing energy consumption, helping the condenser 3 and the compressor 9 to dissipate heat, and extending the equipment life.

[0033] The refrigerator 100 also includes a first fan 1 and a second fan 2 (i.e., a micro fan). The first fan 1 is located in the air duct and is set at the air inlet. It is used to rotate in a first rotation direction in the cooling mode to transfer the cold energy of the evaporator 8 to the storage compartment through the air inlet and the air duct. The second fan 2 is located in the evaporator compartment and is set at the air inlet. It is used to rotate in a second rotation direction opposite to the first rotation direction when the refrigerator is turned on to prevent hot air from the evaporator compartment from entering the air duct through the air inlet.

[0034] like Figure 5 As shown, the refrigerator 100 includes a cabinet 110, which is configured to have at least one compartment 111.

[0035] The multiple compartments 111 can be divided into refrigerator and freezer compartments. The temperature of the refrigerator compartment is usually maintained at 0-10℃, and the temperature is evenly distributed through corresponding evaporators and air circulation. The refrigerator compartment is suitable for storing frequently accessed items such as beverages and sauces, where the temperature fluctuation is relatively large. The temperature of the freezer compartment is consistently stable below -18℃. A corresponding evaporator is used to ensure a low-temperature environment. The freezer compartment can be equipped with pull-out drawers for easy access to bottom-layer foods. The freezer compartment is also equipped with tiered trays to prevent frozen foods from piling up and obstructing cold air circulation, and to prevent upper-layer foods from crushing lower layers during thawing.

[0036] like Figure 6 As shown, the refrigerator 100 also includes a first temperature sensor 120 and a defrost heater 130, wherein the first temperature sensor 120 is used to detect the evaporator temperature; the defrost heater 130 is located in the evaporator compartment and is used to heat the evaporator for defrosting when the refrigerator is turned on.

[0037] In some embodiments, as shown in FIG6, the refrigerator 100 further includes a controller 71, wherein the controller 71 is configured to: acquire the storage compartment temperature when the defrost heater 130 is turned on; determine the temperature change of the storage compartment based on the storage compartment temperature; and control the second fan to turn on when the temperature change reaches the condition used to indicate that the storage compartment is heating up too quickly.

[0038] In this embodiment, when the controller 71 receives a defrosting command and controls the defrosting heater 130 to start working, it begins dynamic monitoring of the storage compartment temperature. The controller determines the temperature change in the storage compartment based on the temperature. For example, the controller collects the storage compartment temperature every minute and calculates the temperature change based on the temperatures of multiple consecutive sampling points. This temperature change is used to determine if the storage compartment is experiencing an abnormally rapid temperature rise. If the temperature change reaches the condition of excessively rapid temperature rise, it is considered that hot air has begun to permeate from the evaporator chamber into the storage compartment through the air duct. At this point, the second fan is immediately triggered to start running, forming an airflow barrier at the air duct to effectively inhibit further intrusion of hot air and prevent the storage compartment temperature from rising further. If the temperature change does not reach the condition of excessively rapid temperature rise, it is determined that the second fan's activation time has not been reached, and the second fan remains stationary. This method of determining the activation timing of the second fan by monitoring the actual temperature rise dynamics of the storage compartment offers higher response sensitivity and control precision compared to methods that rely on indirect inference based on evaporator-side temperature. It not only effectively prevents hot air from escaping into the storage compartment during defrosting, resolving the temperature rise issue caused by defrosting, but also avoids premature or unnecessary fan activation, balancing energy efficiency and food preservation performance, and achieving precise, efficient, and intelligent control of thermal management during the defrosting process.

[0039] According to an embodiment of the present invention, the refrigerator obtains the temperature of the storage compartment when the defrost heater is turned on, determines the temperature change of the storage compartment based on the evaporator temperature, and then determines whether the condition of excessively rapid temperature rise in the storage compartment has been met based on the temperature change. After determining that the condition of excessively rapid temperature rise in the storage compartment has been met, the second fan is controlled to turn on. This allows for precise control of the timing of the second fan's activation based on the storage compartment temperature during the defrosting process, thereby effectively preventing hot air from escaping into the storage compartment during defrosting and solving the problem of temperature rise in the storage compartment caused by defrosting.

[0040] In one embodiment of the present invention, the controller 71 is configured to: when the temperature change exceeds a first preset temperature threshold, confirm that the conditions for indicating that the storage room is heating up too quickly have been met.

[0041] In this embodiment, when the temperature change in the storage compartment exceeds a first preset temperature threshold, for example, exceeding 0.2°C, it indicates that the heat generated by the defrosting heater has significantly affected the thermal environment of the storage compartment, causing its temperature to rise abnormally rapidly. This temperature change serves as a key criterion to identify whether hot air has begun to permeate from the evaporator chamber into the storage compartment through the air duct. Once this temperature change reaches or exceeds the first preset temperature threshold, the controller 71 determines that the condition of excessively rapid temperature rise in the storage compartment is met, confirms that the timing for the second fan to engage has arrived, and immediately controls the second fan to start. Activating the second fan at this time creates a directional airflow barrier at the air outlet or inlet, effectively blocking the backflow of hot air, thereby promptly suppressing further temperature increases in the storage compartment and ensuring the quality of food storage. This judgment mechanism is based on the actual dynamic temperature rise of the storage compartment, responding promptly and logically, avoiding the lag or misjudgment caused by relying solely on evaporator-side parameters, and achieving precise control over the timing of the second fan's intervention.

[0042] In one embodiment of the invention, the controller 71 is configured to determine the amount of temperature change based on a first temperature difference between the storage room temperature sampled at the current sampling time and the storage room temperature sampled at the previous sampling time.

[0043] The temperature of the storage room sampled at the current sampling time is denoted as Tf. n The temperature of the storage room sampled at the previous sampling time is denoted as Tf. n-1 The temperature of the storage room sampled at the time two sampling moments ago is denoted as Tf. n-2 The first temperature difference is denoted as Xn. In this embodiment, the temperature change is determined based on the difference between two consecutive first temperature differences. Specifically, the temperature Tf of the storage room sampled at the current sampling time is calculated. n The storage room temperature Tf compared to the previous sampling time n-1 The first temperature difference between them is Xn, i.e., Xn = Tf n -T fn-1 Calculate the storage room temperature Tf sampled at the previous sampling time. n-1 The storage room temperature Tf sampled at the time two before last n-2The first temperature difference between the two, for example denoted as Xn-1, is used to determine the temperature change, i.e., Xn-Xn-1, based on the difference between the first temperature difference Xn and the first temperature difference Xn-1. This temperature change is used to characterize the changing trend of the temperature rise rate (i.e., the temperature acceleration) of the storage room. This temperature change can more sensitively reflect whether hot air has begun to invade the storage room, thus providing a basis for the precise entry of the second fan and improving the accuracy of determining the timing of the second fan's entry.

[0044] In one embodiment of the present invention, when the second fan is turned on, the controller 71 is configured to control the second fan to operate at a constant speed of a first preset speed.

[0045] In this embodiment, when the controller 71 determines that the conditions for starting the second fan are met, it controls the second fan to operate at a constant speed of a first preset speed. This speed is a fixed value pre-calibrated based on a large amount of experimental data and the characteristics of the overall air duct, aiming to provide stable and appropriate airflow intervention in the initial stage of defrosting or the initial stage of heat migration: on the one hand, it is sufficient to form an effective airflow barrier at the air outlet or air inlet, effectively suppressing the diffusion of hot air from the evaporator compartment to the storage compartment; on the other hand, it avoids increased energy consumption, increased noise, or interference with subsequent refrigeration cycles due to excessively high speed. The constant speed control strategy not only simplifies the control logic and improves the reliability of system operation, but also achieves a balance between rapid response and energy-saving operation while ensuring the thermal barrier effect.

[0046] In one embodiment of the present invention, when the second fan is turned on, the controller 71 is configured to dynamically control the speed of the second fan according to a preset speed control strategy.

[0047] In this embodiment, when the controller 71 determines that the conditions for starting the second fan are met, it dynamically adjusts the fan speed according to a preset speed control strategy. This strategy adaptively adjusts the second fan speed based on real-time parameters during the defrosting process (such as evaporator temperature, storage compartment temperature, defrosting heater heating time, and second fan start-up time). For example, a lower speed is used in the early stages of defrosting when the heat load is low to save energy and reduce noise, while the speed is increased to enhance the thermal barrier effect when a large amount of frost melts and hot air increases significantly. Through this dynamic speed regulation mechanism, the speed of the second fan can adapt to the heat changes in the duct, matching the evaporator cavity heat circulation more precisely. This not only improves defrosting efficiency but also effectively prevents hot air from entering the storage compartment through the air outlet.

[0048] In one embodiment of the present invention, such as Figure 6As shown, the refrigerator 100 also includes a second temperature sensor 140 for detecting the evaporator temperature; the preset speed control strategy includes: the second fan starts operating at a second preset speed, and after starting operation, the speed of the second fan is calculated in real time through a preset speed algorithm; wherein, the speed algorithm includes a calculation relationship for calculating the speed of the second fan based on the current evaporator temperature, and the evaporator temperature is directly proportional to the speed of the second fan; or, the speed algorithm includes a calculation relationship for calculating the speed of the second fan based on a second temperature difference and the heating time of the defrost heater, and the speed of the second fan is directly proportional to the second temperature difference and / or the heating time, wherein the second temperature difference is the temperature difference between the evaporator temperature sampled at the current sampling time and the storage compartment temperature sampled at the current sampling time; or, the speed algorithm includes a calculation relationship for calculating the speed of the second fan based on the second preset speed and the operating time of the second fan, and the speed of the second fan is directly proportional to the operating time.

[0049] For example, the rotational speed of the second fan is denoted as R, the evaporator temperature as Ts, the heating time of the defrosting heater as t, the second preset rotational speed as r1, and the start-up time as Time.

[0050] In this embodiment, the rotational speed of the second fan is dynamically adjusted according to the evaporator temperature Ts detected by the defrosting sensor (i.e., the second temperature sensor 140), and the evaporator temperature is directly proportional to the rotational speed of the second fan.

[0051] Specifically, in the early stages of defrosting, the evaporator temperature Ts is usually in a low negative temperature range, indicating that the heat generated by the defrosting heater is mainly used to melt the frost layer, and hot air has not yet been generated in large quantities. At this time, the demand for air volume is small. Therefore, after the second fan is started, it runs at a lower second preset speed, which effectively reduces energy consumption and noise while maintaining the basic airflow barrier.

[0052] As the defrosting heater continues to operate, the frost layer on the evaporator gradually melts away, and the heat begins to directly heat the evaporator pipes and surrounding air, causing the evaporator temperature Ts to rise rapidly and the amount of hot air to increase significantly. To effectively prevent hot air from entering the storage compartment through the air duct, the system needs to increase the speed of the second fan to enhance airflow obstruction. Therefore, the controller 71 dynamically calculates the speed R of the second fan based on the real-time evaporator temperature Ts, i.e., R = 10 × Ts + 400 (unit: rpm). For example, when Ts = 3℃, R = 430 rpm is calculated. The controller 71 controls the second fan to operate at 430 rpm accordingly, ensuring that the fan speed adapts to the heat changes within the air duct, matching the temperature changes in the air duct. This achieves more precise control of heat circulation within the evaporator chamber, not only improving defrosting efficiency but also effectively preventing hot air from entering the storage compartment through the air outlet. This ensures the stability of the freezer compartment temperature while also considering energy efficiency, noise levels, and user experience.

[0053] In a specific embodiment, the second temperature difference is the temperature difference between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time. For example, referring to Table 1, the evaporator temperature collected at the 10th minute is -5℃, and the storage room temperature collected at the 10th minute is -18℃. Therefore, the temperature difference between the evaporator temperature collected at the 10th minute and the storage room temperature collected at the 10th minute is 13℃. Thus, the second temperature difference is calculated to be 13℃.

[0054] Furthermore, if the rotational speed R of the second fan is determined solely based on the evaporator temperature Ts, the fan speed adjustment may become overly sensitive or even random due to the small fluctuations or measurement variations in Ts at certain stages. This makes it difficult to achieve precise and stable control of the storage compartment temperature. In reality, the rotational speed of the second fan should be strongly correlated with the heating time t of the defrosting heater and the second temperature difference to achieve more precise temperature control. This can be verified in the experimental data in Table 2. For example, if the evaporator temperature is measured at -5℃ at the 10th minute and the storage compartment temperature is collected at -18℃ at the 10th minute, the second temperature difference is 13℃, indicating that the frost layer has significantly melted and the heat transfer efficiency has greatly improved.

[0055] Therefore, the rotational speed of the second fan is calculated by integrating multiple parameters. Specifically, after the second fan starts, its rotational speed is determined by the second temperature difference (e.g., denoted as T2) and the heating time t of the defrosting heater, i.e., R = 10 × T2 + 15 × t = 10 × (Ts - Tf) + 15 × t. From this, the rotational speed of the second fan in the 10th minute can be calculated to be 280 rpm, and the operation of the second fan is controlled according to the rotational speed of 280 rpm.

[0056] refer to Figure 7 At the 8th minute, when the first temperature difference meets the start-up conditions of the second fan, the second fan starts and runs at the second preset speed of 180 rpm. Subsequently, as the evaporator temperature, storage room temperature and heating time continue to rise, in order to effectively suppress and offset the influence of the hot air generated during the defrosting process on the temperature control of the freezer room, the speed of the second fan needs to be gradually increased, showing an obvious phased increasing trend.

[0057]

[0058] Table 1 Furthermore, the speed of the second fan is adjusted in stages based on its operating duration. The second fan's speed R starts from an initial preset value r1 (i.e., the second preset speed) and gradually increases with the operating duration Time (in minutes, rounded to the nearest integer, such as 1 min, 2 min, 3 min, etc.) according to the formula R = r1 + 8 × Time. As the operating duration extends, the second fan's speed R continues to increase until it reaches the second fan's maximum allowable speed. This control method ensures that the second fan can dynamically match changes in heat load during defrosting, achieving more precise temperature control.

[0059] In one embodiment of the present invention, such as Figure 6 As shown, the refrigerator 100 also includes a second temperature sensor 140 for detecting the evaporator temperature. After controlling the second fan to turn on, the controller 71 is further configured to: control the second fan to turn off when it is determined that the conditions for turning off the second fan are met, wherein the conditions for turning off the second fan include: after the defrost heater stops operating, a third temperature difference between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time is less than or equal to a second preset temperature threshold; or, after the defrost heater stops operating, the evaporator temperature is greater than or equal to a third preset temperature threshold, wherein the third preset temperature threshold is greater than or equal to the second preset temperature threshold; or, a fourth temperature difference is less than a fifth temperature difference, wherein the fourth temperature difference is the temperature difference between the storage compartment temperature sampled at the current sampling time and the storage compartment temperature sampled at the previous sampling time, and the fifth temperature difference is the temperature difference between the storage compartment temperature sampled at the previous sampling time and the storage compartment temperature sampled at the time before that.

[0060] In this embodiment, after the defrosting heater stops, the second fan is started at a first preset speed, and its shutdown timing is dynamically determined based on the evaporator temperature. Specifically, while the second fan is running at the first preset speed, a third temperature difference is calculated between the evaporator temperature at the current sampling time and the evaporator temperature at the previous sampling time. When this third temperature difference is less than or equal to a second preset temperature threshold, it indicates that the residual heat after the defrosting heater stops has been largely dissipated, and the second fan can be turned off. The second preset temperature threshold is also determined based on actual operating data and experiments, and its value ranges from -10℃ to 10℃, for example, it can be set to 0℃. For instance, if the evaporator temperature at the current sampling time is 10℃, and the evaporator temperature at the previous sampling time is also 10℃, then the third temperature difference is 0℃, which is equal to the second preset temperature threshold of 0℃, satisfying the shutdown condition for the second fan. At this time, the system will control the second fan to stop running.

[0061] Alternatively, after the defrosting heater stops operating, if the speed of the second fan is jointly controlled by the first temperature difference and the heating time of the defrosting heater, the evaporator temperature can be used as the criterion for cutting off the second fan: when the evaporator temperature is greater than or equal to the third preset temperature threshold, it indicates that the residual heat after the defrosting heater stops has been basically dissipated, and the second fan can be turned off at this time. The third preset temperature threshold can be determined based on actual operating data and experiments, and its value ranges from -5℃ to -30℃, and this third preset temperature threshold is higher than the second preset temperature threshold. For example, the third preset temperature threshold can be set to 10℃.

[0062] Alternatively, after the defrosting heater stops operating, the residual heat from the heating element, still at a high temperature, will continue to dissipate into the evaporator area. If the second fan is immediately shut off at this point, the hot air generated during defrosting may flow back into the storage compartment through the air inlet, causing an abnormal rise in the compartment temperature and affecting the cooling effect and food preservation performance.

[0063] To avoid the above problems, the second fan needs to continue running for a period of time after the defrosting heater stops. Its speed can be dynamically adjusted according to the second preset speed and the duration that the second fan has been running, so as to form an effective airflow barrier and prevent hot air from entering the storage room.

[0064] However, the continuous operation time of the second fan should not be extended indefinitely, otherwise it will cause unnecessary energy consumption. Nor should a fixed delay be simply adopted, as the actual rate of waste heat dissipation is affected by various factors such as ambient temperature and load, making it difficult to balance effectiveness and energy efficiency with a fixed time. Therefore, a better approach is to dynamically determine the optimal shutdown time based on the temperature change trend of the storage room. Refer to Table 2 for details to determine the optimal cut-off time for the second fan.

[0065]

[0066] Table 2 Specifically, during the operation of the second fan, the temperature of the storage room is continuously collected. The temperature difference between the storage room temperature sampled at the current sampling time and the temperature sampled at the previous sampling time is calculated and recorded as the fourth temperature difference. Simultaneously, the temperature difference between the storage room temperature sampled at the previous sampling time and the temperature sampled at the time before that is calculated and recorded as the fifth temperature difference. When the fourth temperature difference is less than the fifth temperature difference, it indicates that the rate of temperature rise in the storage room has significantly slowed down or even stabilized, indicating that the impact of defrosting residual heat on the room has been basically eliminated. At this point, the optimal shutdown point for the second fan can be determined, and the system immediately controls it to stop operating, thereby achieving energy-saving optimization while ensuring temperature control effectiveness.

[0067] Referring to Table 2, if the second fan is set to run for a fixed 8 minutes, the additional daily energy consumption is approximately 0.016 kW·h / 24h. However, based on the comparison between the fourth and fifth differences (e.g., the fourth difference is X4 = 0.5℃ and the fifth difference is X3 = 1℃), the fourth difference is less than the fifth difference, indicating that the temperature rise trend has significantly slowed and the thermal disturbance has essentially ended. In this case, the second fan only needs to run for 4 minutes before shutting down, and the energy consumed by the second fan running for 4 minutes is approximately 0.008 kW·h / 24h. Therefore, this strategy not only meets thermal management requirements but also reduces the average daily energy consumption to approximately 0.008 kW·h / 24h, demonstrating significant energy savings of up to 50%. It achieves precise control and energy efficiency optimization of the timing of the second fan's shutdown.

[0068] In one embodiment of the present invention, before the defrost heater is turned on, the controller 71 is further configured to: control the refrigerator to stop in response to a defrost command; and control the defrost heater to turn on when the evaporator temperature reaches a fourth preset temperature threshold, or when the shutdown time reaches a preset time.

[0069] In this embodiment, before the defrosting heater is turned on, the controller 71 executes a complete pre-control process to ensure that the defrosting process starts safely and efficiently. Specifically, when the controller 71 receives the defrosting command, the controller 71 first controls the entire refrigerator to stop, thereby cutting off the refrigeration cycle, avoiding mutual interference between hot and cold airflows during the defrosting process, and preventing high temperatures from causing thermal shock to the refrigeration system.

[0070] Subsequently, controller 71 enters the defrost start-up judgment stage: on the one hand, it monitors the evaporator temperature collected by the defrost sensor in real time, and on the other hand, it records the downtime simultaneously. When any of the following conditions are met, controller 71 determines that the defrost start-up conditions have been met and controls the defrost heater to start: real-time acquisition of evaporator temperature Ts, when the evaporator temperature Ts reaches the fourth preset temperature threshold, for example, when the evaporator temperature drops to... At 25℃, the defrosting heater stops operating, indicating that the evaporator has cooled sufficiently and the frost structure is stable, making it suitable to begin defrosting. The fourth preset temperature threshold can be a specific temperature value within a range determined by actual operating data and experiments, and can be any specific temperature value from 0℃ to 50℃. If the shutdown duration reaches the preset time, such as 30 minutes, defrosting will be forcibly initiated even if the evaporator temperature has not yet dropped to the target threshold. This prevents severe defrosting delays caused by sensor drift, extreme environments, or abnormal operating conditions, which could affect cooling performance or user experience. This ensures both defrosting accuracy and timely initiation of the defrosting process under safe and controllable conditions.

[0071] In one embodiment of the present invention, the rated operating power of the second fan is less than the rated operating power of the first fan.

[0072] In this embodiment, the first fan is primarily used during the refrigeration cycle, requiring a large air volume to achieve efficient distribution of cold air between the freezer and refrigerator compartments. Therefore, it has high power, strong air pressure, and high air volume capacity. The second fan, however, is dedicated to defrosting, forming a local airflow barrier at the air outlet or inlet to prevent hot air from diffusing from the evaporator compartment to the storage compartment. Its core objective is not high-volume air delivery, but rather precise and low-disturbance control of the local airflow direction and speed. Therefore, the second fan does not require high-power operation; a lower rated power is sufficient to meet the thermal barrier requirements. This design not only effectively reduces additional energy consumption during the defrosting stage but also reduces noise generation and avoids interference with natural thermal convection within the evaporator compartment or affecting subsequent refrigeration recovery due to excessive airflow. Thus, while ensuring effective defrosting thermal management, it also considers overall energy efficiency, quiet operation, and system stability.

[0073] In a specific embodiment, the activation timing of the second fan can also be determined based on the evaporator temperature and the storage compartment temperature. Specifically, the difference T1 between the evaporator temperature Ts and the storage compartment temperature Tf is calculated, i.e., T1 = Ts - Tf. When this difference T1 is greater than a preset temperature threshold (e.g., denoted as X1), i.e., T1 > X1, it is confirmed that the conditions for the second fan to be turned on are met, thereby triggering its activation action. Here, the preset temperature threshold X1 is an empirical setting value determined based on experiments and actual operating data, and its value range is 0~10℃. For example, the first preset temperature threshold X1 is 0℃.

[0074] For example, the evaporator temperature Ts is -10℃ and the storage room temperature is -15℃. At this time, the first temperature difference T1 is 5℃, which satisfies the condition that the difference T1 is greater than the preset temperature threshold X1. This achieves the timing for the second fan to start, satisfies the start-up conditions of the second fan, and thus the controller 71 controls the second fan to start.

[0075] Furthermore, during operation, the defrosting heater 140 can also use the temperature difference between the evaporator and the evaporator as a criterion for determining when the second fan should activate. Specifically, the controller 71 monitors the temperature difference T2 between the evaporator temperature at the current sampling moment and the evaporator temperature at the previous sampling moment, as well as the evaporator temperature itself. When the temperature difference T2 is greater than the preset temperature threshold X2 (i.e., T2 > X2), it indicates that the defrosting process has entered the middle to late stage, the evaporator temperature rises at a faster rate, and the defrosting degree is high. When the evaporator temperature sampled at the current sampling moment is greater than the preset temperature threshold X3, it further confirms that defrosting has progressed to the active heat release stage, thereby improving the accuracy of the judgment. When both conditions are met simultaneously, such as T2 being greater than 3°C and the evaporator temperature at the current sampling moment being greater than -13°C, it is determined that the activation time for the second fan has been reached, and the second fan is controlled to start. X2 and X3 are determined based on actual operating data and experimental experience.

[0076] Specifically, theoretically, the defrosting process and the control of the second fan can be determined solely by the evaporator temperature Ts. However, there are significant limitations in practical applications: the temperature rise of the evaporator Ts is highly nonlinear. For example... Figure 8 As shown, in the initial stage of defrosting, due to the thick frost layer at the bottom of the evaporator, the heat from the defrosting heater is mainly used for defrosting, and the evaporator temperature Ts rises slowly. After the bottom frost has basically melted, the thermal resistance decreases, and the heat is rapidly conducted to the sensor location, significantly accelerating the rate of temperature rise of the evaporator temperature Ts. This characteristic makes it difficult to accurately reflect whether hot air has begun to migrate into the storage compartment based solely on the evaporator temperature Ts.

[0077] What this solution truly needs to protect is the temperature control environment of the storage compartment, and the ideal criterion should be the change in the storage compartment temperature Tf. However, because there is usually a plastic duct wall between the first temperature sensor and the evaporator heater, the heat conduction path is long and the response is delayed, resulting in the storage compartment temperature Tf being insensitive to defrosting thermal disturbances and making it difficult to capture early signals of hot air intrusion in a timely manner.

[0078] Therefore, by combining the advantages of evaporator temperature Ts and storage compartment temperature Tf, a temperature difference T1 or T2 between the two is constructed as a composite entry criterion. During defrosting, both evaporator temperature Ts and storage compartment temperature Tf show an upward trend, but evaporator temperature Ts responds faster due to its direct contact with the piping. When the temperature difference between the two increases significantly, it indicates that sufficient heat has accumulated in the evaporator area, and the hot air tends to diffuse into the air duct. At this time, starting the second fan can precisely intervene in the heat migration process, suppressing the rise in freezer temperature while avoiding energy waste caused by premature start-up and shutdown, thus achieving more reliable and efficient defrosting thermal management.

[0079] Whether the above methods are based on the difference T1 between the evaporator temperature Ts and the storage compartment temperature Tf, the temperature difference T2 between the evaporator temperature at the current sampling time and the evaporator temperature at the previous sampling time, or the evaporator temperature itself, or on the temperature change of the storage compartment to determine the timing of the second fan's entry, they are essentially all "predicting" whether hot air is about to enter the storage compartment through evaporator-side parameters. However, these parameters reflect the heat conducted from the heater to the sensor through the aluminum plate and aluminum pipe, not the actual hot air that has entered the storage compartment. Especially in the first half of defrosting, when the frost layer is still relatively thick, the rise in evaporator temperature Ts is mainly due to heat conduction rather than convection. At this time, even if the evaporator temperature Ts reaches -13℃, the hot air has not yet truly diffused.

[0080] Therefore, utilizing the refrigerator's excellent insulation properties, during defrosting when the refrigerator is off, if there is no external thermal disturbance, the foam layer allows the storage compartment temperature to rise slowly and evenly. Once the temperature change in the storage compartment exceeds the first preset temperature threshold, it indicates that the defrost heater has broken through the critical frost layer, and hot air begins to enter the air duct through convection, affecting the internal environment. This is physically consistent with the accelerated temperature rise phenomenon observed by the defrost sensor after the frost melts, but the temperature change in the storage compartment more directly reflects the "risk of temperature rise in the storage compartment" that users are most concerned about. Referring to Table 1, when the temperature change in the storage compartment per unit time exceeds the first preset temperature threshold (e.g., 0.5℃), the temperature change in the storage compartment is significantly measurable. At the same time, the corresponding evaporator temperature Ts has usually risen to approximately -9℃, and its temperature rise slope also changes abruptly, with the two corroborating each other. Therefore, using a temperature change exceeding the first preset temperature threshold as the condition for the second fan to activate is not only logically sound and has precise response timing, but also effectively avoids energy waste caused by premature startup, demonstrating high feasibility and practicality.

[0081]

[0082] Table 3 Among them, the evaporator temperature difference is the difference between the evaporator temperature at the current sampling time and the evaporator temperature at the previous sampling time, and the storage room temperature difference is the difference between the storage room temperature at the current sampling time and the storage room temperature at the previous sampling time.

[0083] According to an embodiment of the refrigerator of the present invention, when the defrost heater is turned on, the temperature of the storage compartment is obtained, and the temperature change of the storage compartment is determined based on the evaporator temperature. Then, based on the temperature change, it is determined whether the condition for excessively rapid temperature rise in the storage compartment has been met. If the condition for excessively rapid temperature rise in the storage compartment is determined, the second fan is controlled to turn on. This allows for precise control of the timing of the second fan's activation during the defrosting process based on the storage compartment temperature, effectively preventing hot air from escaping into the storage compartment during defrosting and solving the problem of temperature rise in the storage compartment caused by defrosting. Furthermore, based on this, the rotation speed of the second fan is dynamically adjusted in conjunction with the timing of its on / off, so that the rotation speed of the second fan can adapt to the heat changes in the air duct, matching the heat changes within the air duct. This achieves more precise control of heat circulation within the evaporator cavity, not only improving defrosting efficiency but also effectively preventing hot air from entering the storage compartment through the air outlet.

[0084] The following is for reference. Figure 9 A method for controlling a refrigerator according to an embodiment of the present invention is described.

[0085] like Figure 9 As shown, the refrigerator control method of this embodiment includes at least steps S1-S3.

[0086] Step S1: Obtain the temperature of the storage room when the defrosting heater is turned on.

[0087] Step S2: Determine the temperature change of the storage room based on the storage room temperature.

[0088] Step S3: When it is determined that the temperature change reaches the condition used to indicate that the storage room is heating up too fast, control the second fan to turn on to prevent hot air from the evaporator compartment from entering the air duct through the air inlet.

[0089] In one embodiment of the present invention, the refrigerator control method includes: when the temperature change exceeds a first preset temperature threshold, confirming that the conditions for indicating that the storage compartment is heating up too quickly have been met.

[0090] In one embodiment of the present invention, the refrigerator control method further includes: determining the temperature change based on a first temperature difference between the storage compartment temperature sampled at the current sampling time and the storage compartment temperature sampled at the previous sampling time.

[0091] In one embodiment of the present invention, when the second fan is turned on, the controller is configured to control the second fan to operate at a constant speed of a first preset speed.

[0092] In one embodiment of the present invention, when the second fan is turned on, the controller is configured to dynamically control the speed of the second fan according to a preset speed control strategy.

[0093] In one embodiment of the present invention, the preset speed control strategy includes: the second fan is started and operated at a second preset speed, and after starting operation, the speed of the second fan is calculated in real time through a preset speed algorithm; wherein, the speed algorithm includes a calculation relationship for calculating the speed of the second fan based on the current evaporator temperature, and the evaporator temperature is proportional to the speed of the second fan; or, the speed algorithm includes a calculation relationship for calculating the speed of the second fan based on a second temperature difference and the heating time of the defrosting heater, and the speed of the second fan is proportional to the second temperature difference and / or the heating time, wherein the second temperature difference is the temperature difference between the evaporator temperature sampled at the current sampling time and the storage room temperature sampled at the current sampling time; or, the speed algorithm includes a calculation relationship for calculating the speed of the second fan based on the second preset speed and the operating time of the second fan, and the speed of the second fan is proportional to the operating time.

[0094] In one embodiment of the present invention, after controlling the second fan to turn on, the method includes: when it is determined that the conditions for turning off the second fan are met, controlling the second fan to turn off, wherein the conditions for turning off the second fan include: after the defrost heater stops operating, a third temperature difference between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time is less than or equal to a second preset temperature threshold; or, after the defrost heater stops operating, the evaporator temperature is greater than or equal to a third preset temperature threshold, wherein the third preset temperature threshold is greater than or equal to the second preset temperature threshold; or, a fourth temperature difference is less than a fifth temperature difference, wherein the fourth temperature difference is the temperature difference between the storage room temperature sampled at the current sampling time and the storage room temperature sampled at the previous sampling time, and the fifth temperature difference is the temperature difference between the storage room temperature sampled at the previous sampling time and the storage room temperature sampled at the time before that.

[0095] In one embodiment of the present invention, before the defrost heater is turned on, the process includes: controlling the refrigerator to stop in response to a defrost command; and controlling the defrost heater to turn on when the evaporator temperature reaches a fourth preset temperature threshold, or when the shutdown time reaches a preset time.

[0096] In one embodiment of the present invention, the rated operating power of the second fan is less than the rated operating power of the first fan.

[0097] According to the refrigerator control method of this invention, when the defrost heater is turned on, the temperature of the storage compartment is acquired, and the temperature change of the storage compartment is determined based on the evaporator temperature. Then, based on the temperature change, it is determined whether the condition for excessively rapid temperature rise in the storage compartment has been met. If the condition for excessively rapid temperature rise is determined, the second fan is turned on. This allows for precise control of the timing of the second fan's activation during defrosting based on the storage compartment temperature, effectively preventing hot air from escaping into the storage compartment during defrosting and solving the problem of temperature rise in the storage compartment caused by defrosting. Furthermore, based on this, the rotation speed of the second fan is dynamically adjusted in conjunction with the timing of its on / off, so that the fan speed can adapt to the heat changes within the air duct, matching the heat changes within the air duct. This achieves more precise control of heat circulation within the evaporator cavity, not only improving defrosting efficiency but also effectively preventing hot air from entering the storage compartment through the air outlet.

[0098] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0099] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A refrigerator, characterized in that, include: The refrigerator includes a front cover plate, a rear cover plate, and an inner liner. The front cover plate and the rear cover plate form an air duct. The rear cover plate and the inner liner form an evaporator compartment. The rear cover plate has an air inlet. A refrigeration circuit, comprising a compressor, an evaporator, a throttling device, and a condenser, wherein the evaporator is located in the evaporator compartment; A first fan is located in the air duct and is disposed at the air inlet. It is used to rotate in a first rotation direction in the cooling mode to transfer the cooling capacity of the evaporator to the storage room through the air inlet and the air duct. The first temperature sensor is used to detect the temperature of the storage room. A defrosting heater, located inside the evaporator compartment, is used to heat and defrost the evaporator when it is turned on; The second fan is located in the evaporator compartment and is disposed at the air inlet. When turned on, it rotates in a second rotation direction opposite to the first rotation direction to prevent hot air from the evaporator compartment from entering the air duct through the air inlet. The controller is configured to: The temperature of the storage compartment is obtained when the defrosting heater is turned on; The temperature change of the storage room is determined based on the temperature of the storage room. When it is determined that the temperature change reaches the condition used to indicate that the storage room is heating up too quickly, the second fan is controlled to start.

2. The refrigerator according to claim 1, characterized in that, The controller is configured to: When the temperature change exceeds a first preset temperature threshold, it is confirmed that the conditions for indicating that the storage room is heating up too quickly have been met.

3. The refrigerator according to claim 1, characterized in that, The controller is configured to: The temperature change is determined based on a first temperature difference between the storage room temperature sampled at the current sampling time and the storage room temperature sampled at the previous sampling time.

4. The refrigerator according to claim 1, characterized in that, When controlling the second fan to start, the controller is configured to: The second fan is controlled to operate at a constant speed of the first preset speed.

5. The refrigerator according to claim 1, characterized in that, When controlling the second fan to start, the controller is configured to: The speed of the second fan is dynamically controlled according to a preset speed control strategy.

6. The refrigerator according to claim 5, characterized in that, The refrigerator also includes a second temperature sensor for detecting the evaporator temperature; The preset speed control strategy includes: the second fan starts operating at a second preset speed, and after starting operation, the speed of the second fan is calculated in real time through a preset speed algorithm; The speed calculation algorithm includes a computational relationship for calculating the speed of the second fan based on the current evaporator temperature, wherein the evaporator temperature is directly proportional to the speed of the second fan; or... The rotational speed algorithm includes a calculation relationship between the second temperature difference and the heating time of the defrosting heater to determine the rotational speed of the second fan. The rotational speed of the second fan is proportional to the second temperature difference and / or the heating time. The second temperature difference is the temperature difference between the evaporator temperature sampled at the current sampling time and the storage room temperature sampled at the current sampling time; or... The rotational speed algorithm includes a calculation relationship between the second preset rotational speed and the operating duration of the second fan to calculate the rotational speed of the second fan, wherein the rotational speed of the second fan is directly proportional to the operating duration.

7. The refrigerator according to claim 1, characterized in that, The refrigerator also includes a second temperature sensor for detecting the evaporator temperature; After controlling the second fan to start, the controller is also configured to: When it is determined that the conditions for shutting down the second fan are met, the second fan is controlled to shut down, wherein the conditions for shutting down the second fan include: After the defrosting heater stops operating, the third temperature difference between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time is less than or equal to the second preset temperature threshold; or... After the defrosting heater stops operating, the evaporator temperature is greater than or equal to a third preset temperature threshold, wherein the third preset temperature threshold is greater than or equal to a second preset temperature threshold. Alternatively, the fourth temperature difference is less than the fifth temperature difference, wherein the fourth temperature difference is the temperature difference between the storage room temperature sampled at the current sampling time and the storage room temperature sampled at the previous sampling time, and the fifth temperature difference is the temperature difference between the storage room temperature sampled at the previous sampling time and the storage room temperature sampled at the time before that.

8. The refrigerator according to claim 1, characterized in that, Before the defrosting heater is turned on, the controller is also configured to: In response to a defrost command, the refrigerator is controlled to stop. When the evaporator temperature reaches the fourth preset temperature threshold, or when the shutdown time reaches a preset time, the defrosting heater is controlled to turn on.

9. The refrigerator according to claim 1, characterized in that, The rated operating power of the second fan is less than that of the first fan.

10. A control method for a refrigerator as described in any one of claims 1-9, characterized in that, include: The temperature of the storage compartment is obtained when the defrosting heater is turned on; The temperature change of the storage room is determined based on the temperature of the storage room. When it is determined that the temperature change reaches the condition used to indicate that the storage room is heating up too quickly, the second fan is controlled to turn on to prevent hot air from the evaporator compartment from entering the air duct through the air inlet.

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