Refrigerator and control method thereof

Abstract

This invention discloses a refrigerator and its control method. The refrigerator includes a controller configured to: acquire the evaporator temperature and the storage compartment temperature when the defrosting heater is turned on; determine whether the conditions for turning on the second fan are met based on a first temperature difference between the evaporator temperature and the storage compartment temperature; and / or determine whether the conditions for turning on the second fan are met based on a second temperature difference between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time; if the conditions for turning on the second fan are met, control the second fan to turn on. This allows for precise control of the timing of the second fan's activation during defrosting based on the storage compartment temperature and the evaporator temperature, thereby effectively preventing hot air from escaping into the storage compartment during defrosting, solving the temperature rise problem in the storage compartment caused by defrosting, and fully utilizing the residual cold energy of the evaporator to form an airflow barrier to block the backflow of hot air.

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] Refrigerators typically employ finned evaporators in their design, requiring periodic defrosting to maintain cooling efficiency, usually achieved through an electric heater. However, during defrosting, the generated hot air can easily seep into the freezer compartment through the air ducts, causing the freezer temperature to rise. This can lead to partial melting or even spoilage of temperature-sensitive foods such as ice cream and fish, severely impacting user experience and food preservation.

[0003] To address this issue, some related technologies employ a lifting mechanism with a floating fan at the freezer compartment air duct, or install openable and closable baffles at the air outlet to physically block the outflow of hot air during defrosting. While this method can suppress temperature rise, it is structurally complex, costly, and can easily affect the airflow during normal cooling, resulting in insufficient long-term operational reliability. Furthermore, completely blocking the air inlet of the duct prevents hot air from entering and circulating within the duct, causing residual moisture to remain and form stubborn ice particles. Another approach involves controlling the refrigeration fan to reverse, blowing the defrosting hot air back into the evaporator compartment to prevent it from entering the storage compartment. However, the timing of this reversal relies primarily on the real-time temperature of the evaporator, failing to comprehensively consider the freezer compartment temperature and the dynamic thermal state during the defrosting process. This results in limited control precision and difficulty in accurately matching actual heat migration requirements. Summary of the Invention

[0004] 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.

[0005] 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 evaporator temperature; The second 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: When the defrosting heater is turned on, the evaporator temperature and the storage compartment temperature are obtained; The condition for the second fan to be turned on is determined based on the first temperature difference between the evaporator temperature and the storage room temperature, and / or the condition for the second fan to be turned on is determined based on the second temperature difference between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time. If it is determined that the conditions for starting the second fan are met, then the second fan is controlled to start.

[0006] According to an embodiment of the refrigerator of the present invention, when the defrosting heater is turned on, the evaporator temperature and the storage compartment temperature are acquired, and a first temperature difference between the two is calculated based on the evaporator temperature and the storage compartment temperature, and / or a second temperature difference is calculated between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time. Then, it is determined whether the conditions for turning on the second fan are met based on the first temperature difference and / or the second temperature difference. After determining that the conditions for turning on the second fan are met, the second fan is controlled to turn on. Compared with the method of controlling only a single temperature threshold, using the first temperature difference can make the starting time of the second fan more in line with the actual heat migration requirements. Since the first temperature difference takes into account the temperature states of the evaporator temperature and the storage compartment temperature, it can avoid misjudgment caused by ambient temperature fluctuations or changes in refrigerator load. It can effectively suppress unnecessary early operation or response lag of the second fan, thereby improving the control accuracy of the second fan's entry timing. At the same time, the second temperature difference can realize the forward intervention of thermal disturbances, effectively avoiding the temperature rise in the storage compartment caused by response lag. By integrating the dual criteria of static temperature difference and dynamic temperature rise trend, the real-time status of the storage compartment temperature and evaporator temperature can be considered during the defrosting process. This avoids the possibility of false or missed start-ups of the second fan under single parameter control, thereby achieving precise control over the timing of the second fan's activation. This effectively prevents hot air from escaping into the storage compartment during defrosting, solving the problem of temperature rise in the storage compartment caused by defrosting. It can also make full use of the residual cold energy of the evaporator to form an airflow barrier, blocking the backflow of hot air. Thus, while improving food preservation performance, it also takes into account the overall energy consumption and system reliability.

[0007] 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: confirm that the conditions for turning on the second fan are met when the first temperature difference is greater than a first preset temperature threshold and / or the second temperature difference is greater than a second preset temperature threshold.

[0008] The above technical solution has the following advantages or beneficial effects: By comprehensively considering the temperature states of the evaporator and the storage compartment, it avoids misjudgments caused by fluctuations in ambient temperature or changes in refrigerator load. It can effectively suppress unnecessary premature operation or delayed response of the second fan, thereby improving the control accuracy of the second fan's activation timing. At the same time, dynamic judgment can achieve forward-looking intervention, avoid response delay, ensure that the second fan starts at the critical moment, improve the accuracy of the second fan's activation timing, effectively prevent sudden temperature rise in the storage compartment, and thus enable precise control of the second fan's activation timing. This effectively prevents hot air from escaping into the storage compartment during defrosting, solves the problem of temperature rise in the storage compartment caused by defrosting, and can also make full use of the residual cold energy of the evaporator to form an airflow barrier, blocking hot air backflow, improving defrosting efficiency, and reducing energy consumption.

[0009] Furthermore, the controller is configured to: when the second temperature difference is greater than the second preset temperature threshold, and the evaporator temperature sampled at the current sampling time is greater than the third preset temperature threshold, confirm that the conditions for turning on the second fan are met.

[0010] The above technical solution has the following advantages or beneficial effects: it can accurately identify the key nodes where hot air is about to be generated on a large scale and diffuse into the air duct, making the intervention of the second fan more targeted and timely, avoiding energy waste, effectively ensuring the temperature stability of the freezer, and better matching the dynamic characteristics of the actual defrosting process.

[0011] Furthermore, the controller is configured to: when the first temperature difference is greater than a first preset temperature threshold, and the second temperature difference is greater than a second preset temperature threshold, and the evaporator temperature sampled at the current sampling time is greater than a third preset temperature threshold, confirm that the conditions for turning on the second fan are met, wherein the second preset temperature threshold is greater than the third preset temperature threshold.

[0012] The above technical solution has the following advantages or beneficial effects: it improves the accuracy of the timing of intervention, effectively avoids false start-ups or response delays that may be caused by single parameter control, and minimizes the rise in the freezer temperature while ensuring defrosting efficiency.

[0013] 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.

[0014] The above technical solution has the following advantages or beneficial effects: it can simplify the control logic, improve the system reliability, and at the same time achieve a fast, stable and energy-saving thermal barrier effect.

[0015] 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.

[0016] The above technical solution has the following advantages or beneficial effects: it enables the second fan to adapt to changes in heat distribution and airflow characteristics during the defrosting process, effectively suppressing the rise in the freezer temperature while taking into account energy efficiency, noise and system stability, and achieving refined thermal management control.

[0017] Furthermore, 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 using 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 the first temperature difference and the heating time of the defrosting heater, and the speed of the second fan is directly proportional to the first temperature difference and / or the heating 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.

[0018] The above technical solution has the following advantages or beneficial effects: it ensures that the second fan can dynamically match the changes in heat load during the defrosting process, thereby achieving more precise temperature control.

[0019] Furthermore, when the indoor ambient temperature is less than or equal to the preset coil temperature threshold, after controlling the air conditioner to maintain the anti-cold air control mode, the controller is configured to: control the compressor to operate at the second preset frequency and control the indoor fan to stop operating. After controlling the second fan to turn on, the controller is also 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, the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time are... The third temperature difference is less than or equal to the fourth preset temperature threshold; or, after the defrosting heater stops operating, the evaporator temperature is greater than or equal to the fifth preset temperature threshold, wherein the fifth preset temperature threshold is greater than or equal to the fourth preset temperature threshold; or, 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.

[0020] 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.

[0021] 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 sixth preset temperature threshold, or when the shutdown time reaches a preset time.

[0022] The above technical solution has the following advantages or beneficial effects: it ensures that the defrosting process is started in a timely manner under safe and controllable conditions.

[0023] To address the aforementioned problems, this invention also proposes a control method for the refrigerator, comprising: acquiring the evaporator temperature and the storage compartment temperature when the defrosting heater is turned on; determining whether the conditions for turning on the second fan are met based on a first temperature difference between the evaporator temperature and the storage compartment temperature, or determining whether the conditions for turning on the second fan are met based on a second temperature difference between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time; if it is determined that the conditions for turning on the second fan are met, controlling the second fan to turn on to prevent hot air from the evaporator compartment from entering the air duct through the air inlet.

[0024] According to the refrigerator control method of the present invention, when the defrosting heater is turned on, the evaporator temperature and the storage compartment temperature are acquired, and a first temperature difference between the two is calculated based on the evaporator temperature and the storage compartment temperature, and / or a second temperature difference is calculated between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time. Then, it is determined whether the conditions for the second fan to be turned on are met based on the first temperature difference and / or the second temperature difference. After determining that the conditions for the second fan to be turned on are met, the second fan is controlled to be turned on. Compared with the method that relies solely on a single temperature threshold for control, using the first temperature difference allows the start-up timing of the second fan to be more in line with the actual heat migration requirements. Since the first temperature difference takes into account the temperature states of the evaporator temperature and the storage compartment temperature, it can avoid misjudgments caused by ambient temperature fluctuations or changes in refrigerator load, and can effectively suppress unnecessary early operation or response lag of the second fan, thereby improving the control accuracy of the second fan's entry timing. At the same time, the second temperature difference can achieve proactive intervention in thermal disturbances, effectively avoiding temperature rise in the storage compartment caused by response lag. By integrating both static temperature difference and dynamic temperature rise trend as dual criteria, the system can consider the real-time status of the storage compartment temperature and evaporator temperature during defrosting. This avoids potential false starts or missed starts of the second fan under single-parameter control, enabling precise control of the second fan's activation timing. This effectively prevents hot air from escaping into the storage compartment during defrosting, resolving the temperature rise issue caused by defrosting. Furthermore, it fully utilizes the residual cold energy of the evaporator to form an airflow barrier, blocking hot air recirculation. This improves food preservation performance while balancing overall energy consumption and system reliability. In addition, by dynamically adjusting the second fan's speed based on its on / off timing, the fan's speed adapts to the heat changes within the duct, achieving more precise control of heat circulation within the evaporator chamber. This not only improves defrosting efficiency but also effectively prevents hot air from entering the storage compartment through the air outlet.

[0025] 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

[0026] 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 block diagram of a refrigerator according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a refrigerator according to another embodiment of the present invention; Figure 3 This is a schematic diagram of a micro fan structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of a duct assembly according to an embodiment of the present invention; Figure 5 This is a schematic diagram of a refrigerator according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure inside the box according to an embodiment of the present invention; Figure 7 This is a structural block diagram of a refrigerator 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 schematic diagram of the rotational speed change of a second fan according to an embodiment of the present invention; Figure 10 This is a flowchart of a refrigerator control method according to an embodiment of the present invention.

[0027] Explanation of reference numerals in the attached figures: 100 - Refrigerator; 110 - Box body; 111 - Storage room; 01-Front cover of the air duct; 02-Rear cover of the air duct; 03-Inner liner of the refrigerator; 1-First fan; 2-Second fan; 3-Condenser; 6-Throttling device; 8-Evaporator; 9-Compressor; 120 - First temperature sensor; 130 - Second temperature sensor; 140 - Defrosting heater; 71-Controller; 21-Evaporator compartment; 212-Air inlet; 22-Air duct; 221-First air inlet; 222-Second air inlet; 223-First air duct shell; 224-Second air duct shell. Detailed Implementation

[0028] 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.

[0029] The first aspect of the present invention provides a refrigerator.

[0030] Figure 1 This is a block diagram of a refrigerator according to an embodiment of the present invention. The refrigerator 100 includes a cabinet 110 and a door (not shown in the figure). The cabinet 110 can be configured as the outer shell of the refrigerator. The cabinet 110 can typically have a hollow cuboid structure. It should be noted that in other embodiments, the external shape of the cabinet 110 can be designed as needed, and is not limited here. The interior of the cabinet 110 can be used to provide installation space.

[0031] like Figure 1As shown, the housing 110 is constructed with at least one storage compartment 111.

[0032] The multiple storage compartments 111 can include refrigerator and freezer compartments to meet different storage needs, such as refrigeration and freezing, depending on the type of stored items. The temperature in the refrigerator compartment is typically maintained between 0-10℃, with uniform temperature distribution achieved through corresponding evaporator cooling and air circulation. The refrigerator compartment is suitable for storing frequently accessed items such as beverages and sauces, where temperature fluctuations are relatively large. The temperature in the freezer compartment is consistently maintained below -18℃, using a corresponding evaporator to ensure a low-temperature environment. The freezer compartment can be equipped with pull-out drawers for easy access to bottom-layer foods, and also features tiered trays to prevent frozen foods from piling up and obstructing cold air circulation, and to avoid crushing lower layers of food during thawing.

[0033] In some embodiments, a plurality of storage compartments 111 may be provided inside the housing 110. The plurality of storage compartments 111 may be arranged vertically or horizontally within the housing 110.

[0034] In some embodiments, the front side of the cabinet 110 may be provided with a door. The door can be used to open and close the storage compartment 111. The door and the cabinet 110 may be connected by a hinge, so that the refrigerator door can rotate around the axis of the hinge, thereby opening and closing the refrigerator door and thus opening and closing the corresponding storage compartment 111.

[0035] In some embodiments, multiple doors may be provided. These multiple doors may correspond one-to-one with multiple storage compartments 111. It should be noted that in other embodiments, multiple doors may be able to open and close a single storage compartment 111 simultaneously.

[0036] refer to Figure 2 The refrigerator 100 also includes: front cover plate 01 for the air duct, rear cover plate 02 for the air duct, and inner liner 03.

[0037] 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.

[0038] like Figure 2 As shown, the air duct includes a space constructed by a front cover plate 01 and a rear cover plate 02, and a refrigerator inner liner 03. The rear cover plate 02 has an air inlet. A cooling fan 1 (i.e., the first fan) is installed in the air duct. A miniature fan 2 (i.e., the 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 3The 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 4 As shown.

[0039] like Figure 5 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.

[0040] 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.

[0041] 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.

[0042] Further, refer to Figure 6The diagram shows the internal structure of the cabinet, which may contain a refrigerator liner 03. Storage compartments 111 may be formed within the refrigerator liner 03. Multiple refrigerator liners 03 may be installed within the cabinet. These multiple refrigerator liners 03 may be arranged vertically or horizontally within the cabinet. Each refrigerator liner 03 may form one or more storage compartments 111.

[0043] In some embodiments, the refrigerator 100 may include a cooling duct. The cooling duct may be provided with an air inlet 212. The air inlet 212 may connect the interior of the cooling duct and the storage compartment 111. In this way, air in the storage compartment 111 can enter the interior of the cooling duct for cooling to form cold air.

[0044] In some embodiments, the evaporator 8 may be located within a cooling duct. When air from the storage compartment 111 enters the cooling duct, it flows through the evaporator 8, where it exchanges heat with the evaporator 8. The evaporator 8 absorbs heat from the air, thereby cooling and condensing the air to form a large amount of cold air.

[0045] In some embodiments, the cooling duct may be equipped with an exhaust vent. The exhaust vent may connect the interior of the cooling duct and the storage compartment 111. When air in the storage compartment 111 enters the cooling duct through the air inlet 212, the cold air generated by the cooling duct can be delivered to the interior of the storage compartment 111 through the exhaust vent, cooling the interior of the storage compartment 111 and realizing the cooling function of the storage compartment 111. In this way, a cooling air circulation can be formed between the storage compartment 111 and the interior of the cooling duct through the air inlet 212 and the exhaust vent.

[0046] Please see Figure 6 As shown, in some embodiments, the refrigerator 100 may include an evaporator compartment 21. The evaporator compartment 21 may be located in the rear region of the storage compartment 111. The air inlet 212 of the cooling air duct may be located on the side wall of the evaporator compartment 21. The air inlet 212 of the cooling air duct may connect the interior of the evaporator compartment 21 and the storage compartment 111. In this way, air in the storage compartment 111 can enter the evaporator compartment 21 through the air inlet 212 of the cooling air duct for cooling.

[0047] In some embodiments, the refrigerator 100 may include a first air duct housing 223. The first air duct housing 223 may cover the back side of the storage compartment 111. The evaporator compartment 21 may be formed between the first air duct housing 223 and the rear wall of the refrigerator inner liner 03. The air inlet 212 may be formed on the bottom wall of the first air duct housing 223.

[0048] Please see Figure 6As shown, in some embodiments, the refrigerator 100 may include an air duct 22. The air duct 22 may be disposed between the storage compartment 111 and the evaporator compartment 21. The back of the air duct 22 is connected to the evaporator compartment 21. The exhaust port of the cooling air duct may be disposed on the side wall of the air duct 22. In this way, air in the evaporator compartment 21 can enter the air duct 22, and then deliver cold air to the storage compartment 111 through the exhaust port of the cooling air duct, thereby achieving cooling in the storage compartment 111.

[0049] In some embodiments, the refrigerator 100 may include a second air duct housing 224. The second air duct housing 224 may cover the front side of the first air duct housing 223, thereby forming an air duct 22 between the first air duct housing 223 and the second air duct housing 224. The exhaust port of the refrigeration air duct may be opened on the front wall or other side wall of the second air duct housing 224.

[0050] Please see Figure 7 As shown, in some embodiments, a first air inlet 221 may be provided on the side wall of the air duct 22. The first air inlet 221 may be provided on the side wall of the first air duct shell 223. The first air inlet 221 may connect the evaporator chamber 21 and the air duct 22, so that the cold air in the evaporator chamber 21 can enter the air duct 22 through the first air inlet 221.

[0051] Please see Figure 6 As shown, in some embodiments, a second air inlet 222 may be provided on the side wall of the air duct 22, the second air inlet 222 corresponding to Figure 3 The first air inlet is the air inlet of the storage compartment 111. The second air inlet 222 can be opened on the side wall of the second air duct shell 224. The second air inlet 222 can serve as the exhaust outlet of the cooling air duct. The second air inlet 222 can connect the ventilation duct 22 and the storage compartment 111, so that the cold air in the evaporator chamber 21 can enter the air duct 22 through the first air inlet 221 and be discharged into the storage compartment 111 through the second air inlet 222 of the air duct 22, thereby achieving cooling in the storage compartment 111. In other words, the second air inlet 222 is the cold air inlet of the storage room 111, used to receive cold air from the air duct 22 to achieve cooling; at the same time, it is also the air outlet of the airflow inside the air duct 22, which discharges the cold air that has been drawn in through the first air inlet 221 and transported in the air duct 22 to the storage room 111, thereby completing the cold air circulation path from the evaporator chamber 21 to the storage room 111.

[0052] In some embodiments, the air duct 22 may be provided with a plurality of second air inlets 222. The plurality of second air inlets 222 may be arranged at intervals on the air duct 22. The plurality of second air inlets 222 may be arranged at intervals on the rear wall of the storage compartment 111. The plurality of second air inlets 222 may be arranged vertically at intervals. The plurality of second air inlets 222 may also be arranged horizontally at intervals. Thus, the cold air entering the air duct 22 from the evaporator compartment 21 can be delivered to different areas of the storage compartment 111 through the plurality of second air inlets 222, thereby improving the uniformity of temperature distribution within the storage compartment 111.

[0053] It should be noted that the number and position of the second air inlet 222 on the air duct 22 can be adjusted as needed, and no restrictions are imposed here.

[0054] Further, refer to Figure 6 As shown, in some embodiments, the side of the first fan 1 closest to the first air inlet 221 can be the air intake side of the first fan 1, so that the first fan 1 can draw cold air from the evaporator chamber 21 through the air inlet 221. In this way, the first fan 1 can draw air from the evaporator chamber 21 more efficiently, thereby improving the extraction efficiency of the first fan 1.

[0055] In some embodiments, the first fan 1 can blow air to its periphery. As a result, the cold air in the evaporator chamber 21 passes through the first air inlet 221 and is blown from the periphery of the first fan 1 into the air duct 22, and then enters the storage compartment 111 through the second air inlet 222 on the second air duct shell 224, thereby achieving cooling of the storage compartment 111.

[0056] In some embodiments, the second fan 2 may be located at the first air inlet 221. The second fan 2 may be used to draw air from the air duct 22 through the first air inlet 221 and deliver the drawn air to the evaporator chamber 21 through the first air inlet 221.

[0057] like Figure 7 As shown, the refrigerator 100 also includes a first temperature sensor 120, a second temperature sensor 130, and a defrost heater 140. The first temperature sensor 120 can be installed on the surface of the evaporator or close to the evaporator pipes to detect the evaporator temperature. The second temperature sensor 130 can be located inside the storage compartment (such as the freezer compartment) to detect the storage compartment temperature. The defrost heater 140 is located inside the evaporator compartment, for example, installed at the bottom of the evaporator or close to the evaporator coils, to heat the evaporator for defrosting when the refrigerator is turned on.

[0058] In some embodiments, such as Figure 7As shown, the refrigerator 100 also includes a controller 71, wherein the controller 71 is configured to: acquire the evaporator temperature and the storage compartment temperature when the defrosting heater 140 is turned on; determine whether the conditions for turning on the second fan are met based on a first temperature difference between the evaporator temperature and the storage compartment temperature, and / or determine whether the conditions for turning on the second fan are met based on a second temperature difference between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time; if it is determined that the conditions for turning on the second fan are met, then control the second fan to turn on.

[0059] For example, the evaporator temperature is denoted as Ts, the storage room temperature is denoted as Tf, and the first temperature difference is denoted as T1.

[0060] In this embodiment, when the defrosting heater 140 is started, the controller 71 acquires the evaporator temperature and the temperature of the storage compartment (such as the freezer compartment) in real time, and calculates the first temperature difference, i.e., T1=Ts-Tf. The first temperature difference T1 is the cut-off temperature for the second fan to start, and is used as the condition for the second fan to start. Compared with the method of controlling only a single temperature threshold, using the first temperature difference T1 can make the start-up timing of the second fan more in line with the actual heat transfer requirements. Since the first temperature difference T1 takes into account the temperature states of the evaporator temperature Ts and the storage compartment temperature Tf, it can avoid misjudgments caused by ambient temperature fluctuations or changes in refrigerator load, and can effectively suppress unnecessary early operation or response lag of the second fan, thereby improving the control accuracy of the second fan's start-up timing.

[0061] In addition, the controller 71 will also detect the dynamic changes of the evaporator temperature in real time, so as to obtain the evaporator temperature collected at the current sampling time and record it as Ts1, and the evaporator temperature collected at the previous sampling time and record it as Ts2. Then, it calculates the second temperature difference between the evaporator temperature collected at the current sampling time and the evaporator temperature collected at the previous sampling time. For example, if the second temperature difference is recorded as T2, then T2=Ts1-Ts2. The second temperature difference T2 essentially represents the rate of increase of the evaporator temperature during the defrosting process. Then, the controller 71 can determine whether the conditions for the second fan to be turned on are met based on the second temperature difference T2, and determine whether the timing for the second fan to be turned on has been reached. This can realize the proactive intervention of thermal disturbances, effectively avoid the room temperature rise caused by response lag, and thus improve the temperature control accuracy and food preservation performance.

[0062] When the logical condition based on the first temperature difference T1, the second temperature difference T2, or a combination of both is met, the system determines that the activation timing for the second fan has been reached and issues a command to start the second fan. If the activation conditions for the second fan are not met, the system will keep the second fan stationary. By integrating the dual criteria of static temperature difference and dynamic temperature rise trend, the system can consider the real-time status of the storage compartment temperature and the evaporator temperature during defrosting, avoiding the possibility of false or missed starts of the second fan under single-parameter control. This achieves precise control over the activation timing of the second fan, effectively preventing hot air from escaping into the storage compartment during defrosting, solving the temperature rise problem in the storage compartment caused by defrosting, and fully utilizing the residual cold energy of the evaporator to form an airflow barrier, blocking the backflow of hot air. Thus, while improving food preservation performance, the system also considers overall energy consumption and system reliability.

[0063] The function of the second fan is to actively intervene in the airflow direction or velocity within the duct during defrosting, effectively preventing hot air from escaping from the evaporator compartment through the duct into the storage compartment, thereby alleviating the temperature rise problem in the storage compartment caused by defrosting. The entire control logic revolves around the defrosting cycle: once the defrosting heater starts, the second fan can start synchronously or asynchronously according to preset logic; as the defrosting process progresses, when the defrosting heater reaches the set temperature or the defrosting program is completed and stops working, the second fan also stops synchronously or asynchronously according to the strategy. The timing of the second fan's activation directly determines whether hot air can be effectively confined within the evaporator area. If it activates too early, it may interfere with the normal refrigeration cycle; if it activates too late, it cannot prevent hot air from entering the freezer compartment. Therefore, by fusing and judging multi-dimensional temperature information, precise and adaptive control of the second fan's activation is achieved, which not only effectively suppresses the temperature rise in the storage compartment and ensures the quality of food storage, but also improves the overall defrosting efficiency and system energy efficiency.

[0064] According to an embodiment of the refrigerator of the present invention, when the defrosting heater is turned on, the evaporator temperature and the storage compartment temperature are acquired, and a first temperature difference between the two is calculated based on the evaporator temperature and the storage compartment temperature, and / or a second temperature difference is calculated between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time. Then, it is determined whether the conditions for turning on the second fan are met based on the first temperature difference and / or the second temperature difference. After determining that the conditions for turning on the second fan are met, the second fan is controlled to turn on. Compared with the method of controlling only a single temperature threshold, using the first temperature difference can make the starting time of the second fan more in line with the actual heat migration requirements. Since the first temperature difference takes into account the temperature states of the evaporator temperature and the storage compartment temperature, it can avoid misjudgment caused by ambient temperature fluctuations or changes in refrigerator load. It can effectively suppress unnecessary early operation or response lag of the second fan, thereby improving the control accuracy of the second fan's entry timing. At the same time, the second temperature difference can realize the forward intervention of thermal disturbances, effectively avoiding the temperature rise in the storage compartment caused by response lag. By integrating the dual criteria of static temperature difference and dynamic temperature rise trend, the real-time status of the storage compartment temperature and evaporator temperature can be considered during the defrosting process. This avoids the possibility of false or missed start-ups of the second fan under single parameter control, thereby achieving precise control over the timing of the second fan's activation. This effectively prevents hot air from escaping into the storage compartment during defrosting, solving the problem of temperature rise in the storage compartment caused by defrosting. It can also make full use of the residual cold energy of the evaporator to form an airflow barrier, blocking the backflow of hot air. Thus, while improving food preservation performance, it also takes into account the overall energy consumption and system reliability.

[0065] In one embodiment of the present invention, the controller 71 is configured to: confirm that the conditions for starting the second fan are met when the first temperature difference is greater than the first preset temperature threshold and / or the second temperature difference is greater than the second preset temperature threshold.

[0066] The first preset temperature threshold is denoted as X1, and the second preset temperature threshold is denoted as X2.

[0067] In this embodiment, when the first temperature difference T1 is greater than the first preset temperature threshold X1 (i.e., T1>X1), it indicates that there is a significant thermal potential difference between the evaporator and the storage compartment, and the hot air has the driving force to migrate towards the storage compartment. This confirms that the conditions for the second fan to start are met, thus triggering its activation. This comprehensive consideration of the temperature states of both the evaporator and the storage compartment avoids misjudgments caused by ambient temperature fluctuations or changes in refrigerator load, effectively suppressing unnecessary premature operation or delayed response of the second fan, thereby improving the control accuracy of the second fan's activation timing. The first preset temperature threshold X1 is an empirically set value determined based on experiments and actual operating data, with a range of 0~10℃, for example, the first preset temperature threshold X1 is 0℃.

[0068] For example, the evaporator temperature Ts is -15℃ and the storage room temperature is -20℃. At this time, the first temperature difference T1 is 5℃, which satisfies the condition that the first temperature difference T1 is greater than the first 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.

[0069] Specifically, theoretically, the defrosting process and triggering of the second fan can be determined solely based on the evaporator temperature Ts. However, practical applications show that this method has significant limitations: firstly, the temperature rise of the evaporator Ts is not linear. For example... Figure 8 As shown, in the initial stage of defrosting, due to the thicker frost layer at the bottom of the evaporator, the heat generated by the defrosting heater is mainly used to melt the bottom frost layer, resulting in a slow rise in evaporator temperature Ts. However, once the bottom frost has mostly melted, heat is more easily conducted to the upper part of the evaporator, and the rate of temperature rise of evaporator temperature Ts accelerates significantly. This nonlinear characteristic makes it difficult to accurately reflect whether hot air has begun to migrate into the freezer compartment by simply relying on the evaporator temperature Ts.

[0070] On the other hand, the core object to be protected is the storage environment of food in the storage room, that is, the stability of the storage room temperature Tf should be the control target. Ideally, the change in storage room temperature Tf should be directly used as the key criterion for the second fan to start. However, there are technical obstacles in practice: there is usually a plastic duct wall between the second temperature sensor 130 and the evaporator heater 140, resulting in a long heat conduction path and a delayed response. This makes the storage room temperature Tf insensitive to defrosting thermal disturbances and slow to change, making it difficult to promptly reflect whether hot air has entered the duct or is about to enter the storage room.

[0071] To address the aforementioned technical challenges, by combining the advantages of both the evaporator temperature Ts and the storage compartment temperature Tf, a first temperature difference T1=Ts between the two is constructed. Tf serves as a composite criterion for the second fan's entry. During defrosting, the defrosting heater 140 causes both the evaporator temperature Ts and the storage compartment temperature Tf to rise. However, because the evaporator temperature Ts is in direct contact with the evaporator piping, its response speed is much faster than that of the storage compartment temperature Tf, which is affected by the duct isolation. Therefore, when a significant temperature difference appears between the two, it indicates that sufficient heat has accumulated in the evaporator area, and the hot air has a tendency to diffuse downstream into the duct.

[0072] Table 1 is a reference table for when the second fan should be activated. As shown in Table 1, when the first temperature difference T1 reaches approximately 5°C, the second fan is activated, resulting in the smallest increase in room temperature and the best preservation effect. Although the activation time of the second fan is relatively late (e.g., about 45 minutes after defrosting begins), the overall energy consumption increase is limited due to the lower power of the second fan, achieving an optimal balance between energy efficiency and temperature control performance. Therefore, the first preset temperature threshold X1 is determined as the preferred threshold for when the second fan should be activated.

[0073]

[0074] Table 1 Furthermore, when the second temperature difference T1 is greater than the second preset temperature threshold X2, it indicates that the defrosting process has entered the middle and late stages, the evaporator temperature rises at a faster rate, and the degree of defrosting is high. At this time, the controller 71 determines that the conditions for the second fan to start have been met and controls the second fan to start. This dynamic judgment can achieve proactive intervention, avoid response lag, ensure that the second fan starts at a critical moment, improve the accuracy of the second fan's start-up timing, and effectively prevent a sudden rise in the temperature of the storage room. The second preset temperature threshold X2 is an empirically set value, for example, 3°C, used to characterize the critical node of accelerated defrosting heat release, thereby intervening in a timely manner before a large amount of hot air is generated and diffuses into the air duct.

[0075] In one embodiment of the present invention, the controller 71 is configured to: when the second temperature difference is greater than the second preset temperature threshold and the evaporator temperature sampled at the current sampling time is greater than the third preset temperature threshold, confirm that the condition for the second fan to be turned on is met.

[0076] In this embodiment, during the operation of the defrosting heater 140, the controller 71 detects the second temperature difference T2 and the evaporator temperature in real time. When the second temperature difference T2 is detected to be greater than the second preset temperature threshold X2, i.e., T2>X2, it indicates that the defrosting process has entered the middle and late stages, the evaporator temperature rises at a faster rate, and the degree of defrosting is high. When the evaporator temperature sampled at the current sampling time is greater than the third preset temperature threshold, it is used to further confirm that the defrosting has progressed to the active heat release stage, thereby improving the accuracy of the judgment. When both conditions are met at the same time, such as the second temperature difference T2 being greater than 3°C and the evaporator temperature at the current sampling time being greater than -13°C, it is determined that the second fan has reached the activation time, and the second fan is controlled to start.

[0077] The second preset temperature threshold X2 and the third preset temperature threshold are determined based on actual operating data and experimental experience.

[0078] Specifically, theoretically, the evaporator temperature Ts alone can be used as the basis for controlling the activation of the second fan. However, in practical applications, this method has significant limitations: the heating process of the evaporator temperature Ts is not linear. (Reference) Figure 7 As shown, in the initial stage of defrosting, due to the thick frost layer at the bottom of the evaporator, the heat generated by the defrost heater is mainly used to melt the bottom frost, making it difficult to effectively transfer heat to the defrost sensor installed at the top or middle of the evaporator. Therefore, the evaporator temperature Ts rises slowly. However, once the bottom frost layer has mostly melted, the thermal resistance decreases significantly, and heat is rapidly conducted upwards, causing the evaporator temperature Ts to rise sharply in the middle and later stages of defrosting. This non-linear temperature response characteristic makes it difficult to accurately determine whether hot air has the risk of migrating into the freezer compartment simply by relying on the evaporator temperature Ts.

[0079] To address this issue, the evaporator temperature change rate (i.e., the heating rate) will be introduced as a key control parameter. Specifically, the controller 71 continuously calculates the second temperature difference T2=Ts1 between the evaporator temperature at the current sampling moment and the evaporator temperature at the previous sampling moment. Ts2 is used as a dynamic indicator to reflect the activity of the defrosting process. When the second temperature difference T2 exceeds the second preset temperature threshold X2, for example, X2=3℃, it indicates that the frost layer has melted in large quantities, the heat conduction efficiency has been significantly improved, and a large amount of hot air is about to be generated and diffused into the air duct. At this time, the second fan should be started to intervene.

[0080] Table 2 shows the evaporator temperature and the second temperature difference at different time points after defrosting. Referring to Table 2: In the first 1-5 minutes after defrosting begins, the evaporator temperature Ts rises very slowly (less than 1°C per minute). This is because the bottom of the evaporator is still covered by thick frost, and a large amount of heat is consumed in defrosting, making it difficult to effectively transfer to the sensor location. In the 6th-10th minute, as the frost layer at the bottom gradually melts, the heat conduction path improves, and the rate of temperature rise of the evaporator temperature Ts increases significantly. By the 8th minute, the system detects that the second temperature difference T2 reaches 3°C (i.e., T2>X2), and the current evaporator temperature has risen to -13°C.

[0081] When both of the above conditions are met, the controller 71 determines that the peak heat release period has been reached and immediately starts the second fan to prevent hot air from escaping into the freezer compartment.

[0082] However, triggering the second fan based solely on a single temperature threshold (such as a fixed evaporator temperature) can easily lead to premature activation, unnecessarily increasing energy consumption and potentially disrupting the normal refrigeration cycle. By combining the rate of temperature change with its own temperature variation for dual assessment, the system accurately identifies critical points where large-scale hot air generation and diffusion into the air duct are imminent. This makes the intervention of the second fan more targeted and timely, avoiding energy waste, effectively ensuring the temperature stability of the freezer compartment, and better reflecting the dynamic characteristics of the actual defrosting process.

[0083]

[0084] Table 2 In one embodiment of the present invention, the controller 71 is configured to: confirm that the conditions for starting the second fan are met when the first temperature difference is greater than the first preset temperature threshold, the second temperature difference is greater than the second preset temperature threshold, and the evaporator temperature sampled at the current sampling time is greater than the third preset temperature threshold, wherein the second preset temperature threshold is greater than the third preset temperature threshold.

[0085] In this embodiment, the controller 71 is configured to use a triple temperature criterion to collaboratively determine the start-up timing of the second fan: the first temperature difference T1 is greater than the first preset temperature threshold X1, i.e., T1>X1; the second temperature difference T2 is greater than the second preset temperature threshold X2, i.e., T2>X2; and the evaporator temperature measured at the current sampling time is greater than the third preset temperature threshold. Only when all three conditions are met simultaneously is it confirmed that the start-up condition of the second fan has been met and its start-up controlled.

[0086] For example, the first preset temperature threshold X1 is 5℃, the second preset temperature threshold X2 is 3℃, and the third preset temperature threshold is -13℃. When T1 > 5℃ and T2 > 3℃, and the evaporator temperature sampled at the current sampling time is greater than -13℃, the system confirms that the conditions for starting the second fan have been met and controls the second fan to start. This system comprehensively considers the thermal potential difference, temperature rise dynamics, and absolute temperature status: only when a significant temperature difference has formed between the evaporator and the storage compartment (indicating the presence of a heat migration driving force), the evaporator temperature is rising rapidly (indicating that a large amount of frost has melted and heat transfer efficiency has improved), and the evaporator temperature itself has risen to the typical range of the mid-to-late defrosting stage, does the system determine that hot air is about to or has already begun to diffuse into the air duct. Starting the second fan at this time achieves the most timely and efficient thermal isolation. This multi-dimensional integrated judgment mechanism significantly improves the accuracy of the timing of the intervention, effectively avoiding false starts or response delays that may be caused by single-parameter control, and minimizing the rise in the freezer room temperature while ensuring defrosting efficiency.

[0087] In addition, in a specific embodiment, the start-up conditions of the second fan can be determined based on the temperature difference caused by the rise in the storage room temperature.

[0088] Specifically, the system acquires the storage room temperature at the current moment, the storage room temperature at the previous moment, and the storage room temperature at the moment before that. For example, the storage room temperature can be acquired every minute. The system calculates the first temperature difference between the storage room temperature acquired at the current moment and the storage room temperature acquired at the previous moment, and the second temperature difference between the storage room temperature acquired at the previous moment and the storage room temperature at the moment before that. Then, the system calculates the change between the first temperature difference and the second temperature difference. When the change is greater than a preset change (e.g., 0.2℃), it indicates that the storage room temperature is showing an accelerating upward trend, which may be affected by the intrusion of defrosting heat. At this time, the system determines that the timing for the second fan to be activated has been reached and controls it to start. If the condition is not met, the second fan remains in the off state. This method, by monitoring changes in the temperature of the storage compartment, can more sensitively capture early signals that hot air is beginning to seep into the freezer compartment. This allows for timely intervention when the temperature rise is not yet significant but the trend has already emerged, thereby enhancing the protection of the food storage environment and avoiding response lag caused by relying solely on evaporator-side parameters.

[0089] 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.

[0090] 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 first preset speed is a fixed value pre-calibrated based on extensive experimental data and the characteristics of the system's air duct, designed to provide stable and moderate airflow intervention during the initial defrosting or heat migration phase. On one hand, this first preset speed is sufficient to form an effective airflow barrier at the air outlet or inlet, inhibiting the diffusion of hot air from the evaporator chamber towards the storage compartment; on the other hand, it avoids unnecessary increases in energy consumption, noise, or disturbances to the refrigeration cycle caused by excessively high speeds. Adopting a constant speed control strategy also simplifies the control logic, improves system reliability, and achieves a rapid, stable, and energy-efficient heat barrier effect.

[0091] 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.

[0092] In this embodiment, when the controller 71 determines that the conditions for starting the second fan are met, it dynamically adjusts the speed of the second fan according to a preset speed control strategy. This control strategy adjusts the speed of the second fan in real time based on multi-dimensional parameters during the defrosting process. For example, it combines information such as evaporator temperature, defrosting heater heating time, and second fan start-up time to generate a target speed that matches the current heat load state. This allows the second fan to adapt to changes in heat distribution and airflow characteristics during the defrosting process, effectively suppressing the rise in freezer temperature while taking into account energy efficiency, noise, and system stability, thus achieving refined thermal management control.

[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 first temperature difference and the heating time of the defrosting heater, and the speed of the second fan is proportional to the first temperature difference and / or the heating 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] 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.

[0095] In this embodiment, the rotational speed of the second fan is dynamically adjusted as the evaporator temperature Ts detected by the defrost sensor (i.e., the first temperature sensor 120) increases. This is because in the initial stage of defrosting, the evaporator temperature Ts is low (e.g., still in the negative temperature range), indicating that the heat generated by the defrost heater is mainly used to melt the frost layer, and a large amount of hot air has not yet been generated. At this time, the demand for airflow is small, and there is no need for the second fan to operate at high speed. Therefore, after the second fan starts, it operates at a lower second preset speed in the initial stage to balance energy consumption and basic airflow barrier effect.

[0096] As the defrosting heater continues to operate, the frost layer on the evaporator gradually melts away. The heat released by the defrosting heater begins to directly heat the evaporator pipes and the surrounding air, causing the evaporator temperature Ts to rise rapidly and the amount of hot air to increase significantly. At this point, in order to effectively prevent hot air from entering the freezer compartment through the air duct, the speed of the second fan needs to be increased to enhance the airflow barrier capability.

[0097] To this end, the controller 71 dynamically determines the target speed R of the second fan based on the real-time evaporator temperature Ts using a preset algorithm, i.e., R = 10 × Ts + 400. For example, when the current evaporator temperature Ts = 2℃ is detected, the calculated speed of the second fan is R = 10 × 2 + 400 = 420 rpm, and the controller 71 controls the second fan to operate at a speed of 420 rpm accordingly. This achieves precise matching between the speed of the second fan and the defrosting process: low-speed operation to save energy and reduce noise when the heat load is low, and automatic increase in speed to enhance the thermal insulation effect during peak heat release periods, thereby optimizing the overall energy efficiency and user experience while ensuring the stability of the freezer compartment temperature.

[0098] Furthermore, due to the small range of variables, determining the second fan speed R solely based on the evaporator temperature Ts would result in overly random speed variations, making precise temperature control difficult. In reality, the second fan speed should be determined by the defrosting heater's heating time t and the first temperature difference T1, i.e., Ts. A strong correlation between Tf and temperature parameters was found to enable more precise temperature control, which can be verified in the experimental data in Table 3. Table 3 shows the correlation data between heating time, temperature parameters, and second fan speed during the defrosting process.

[0099]

[0100] Table 3 Specifically, when calculating the rotational speed R of the second fan using the first temperature difference T1 and the heating time t of the defrosting heater, R = 10 × T1 + 15 × t = 10 × (Ts - Tf) + 15 × t. For example, if the evaporator temperature is measured to be -13℃ at the 9th minute and the storage room temperature is measured to be -19℃ at the 9th minute, then the first temperature difference is 6℃. From this, the rotational speed of the second fan at the 9th minute can be calculated to be 230 rpm, and the second fan is then controlled to operate at a speed of 230 rpm.

[0101] refer to Figure 9 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.

[0102] 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.

[0103] In one embodiment of the present invention, 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 fourth preset temperature threshold; or, after the defrost heater stops operating, the evaporator temperature is greater than or equal to a fifth preset temperature threshold, wherein the fifth preset temperature threshold is greater than or equal to the fourth preset temperature threshold; or, 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.

[0104] In this embodiment, after the defrosting heater stops, the second fan starts running 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 fourth 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 fourth 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℃.

[0105] For example, 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 preset cut-out threshold (i.e., the fourth preset temperature threshold of 0℃), satisfying the shutdown condition of the second fan. At this time, the system will control the second fan to stop running.

[0106] 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 fifth 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 fifth preset temperature threshold can be determined based on actual operating data and experiments, and its value ranges from -5℃ to -30℃, and this fifth preset temperature threshold is higher than the fourth preset temperature threshold. For example, the fifth preset temperature threshold can be set to 10℃.

[0107] 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.

[0108] 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.

[0109] 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 (because the actual rate of waste heat dissipation is affected by various factors such as ambient temperature and load, and a fixed time is difficult to balance effect and energy efficiency). Therefore, a better approach is to dynamically determine the optimal shutdown time based on the temperature change trend of the storage room.

[0110] 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.

[0111] In one embodiment of the present invention, before the defrost heater is turned on, the controller 71 is further configured to: control the refrigerator 100 to stop in response to a defrost command; and control the defrost heater to turn on when the evaporator temperature reaches a sixth preset temperature threshold, or when the shutdown time reaches a preset time.

[0112] In this embodiment, when a defrosting command is received, the refrigerator 100 is first shut down to avoid interference with the defrosting process caused by the operation of the refrigeration system; then, the evaporator temperature is monitored in real time, and it is determined whether the start-up conditions of the defrosting heater are met.

[0113] Specifically, when the evaporator temperature drops to the sixth 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 layer structure is stable, making it suitable to start 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℃; or if the refrigerator shutdown time has reached the preset maximum waiting time (to prevent defrosting from failing to start due to abnormal temperature sensors, etc.), the controller 71 will immediately control the defrosting heater to start, thereby ensuring that the defrosting process starts in a timely manner under safe and controllable conditions.

[0114] According to an embodiment of the refrigerator of the present invention, when the defrosting heater is turned on, the evaporator temperature and the storage compartment temperature are obtained, and a first temperature difference between the two is calculated based on the evaporator temperature and the storage compartment temperature, and / or a second temperature difference is calculated between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time. Then, based on the first temperature difference and / or the second temperature difference, it is determined whether the conditions for turning on the second fan are met. After determining that the conditions for turning on the second fan are met, 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 and the evaporator temperature, 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. Furthermore, based on this, the speed of the second fan is dynamically adjusted in conjunction with the timing of its opening or closing, so that the speed of the second fan can adapt to the heat changes in the air duct and match them with the heat changes in the air duct. This achieves more precise control of the heat circulation in the evaporator chamber, which not only improves defrosting efficiency but also effectively prevents hot air from entering the storage room through the air outlet.

[0115] The following is for reference. Figure 10 A method for controlling a refrigerator according to an embodiment of the present invention is described.

[0116] like Figure 10 As shown, the refrigerator control method of this embodiment includes at least steps S1-S3.

[0117] Step S1: When the defrosting heater is turned on, obtain the evaporator temperature and the storage room temperature.

[0118] Step S2: Determine whether the conditions for turning on the second fan are met based on the first temperature difference between the evaporator temperature and the storage room temperature, or determine whether the conditions for turning on the second fan are met based on the second temperature difference between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time.

[0119] Step S3: If it is determined that the conditions for the second fan to be turned on are met, then the second fan is turned on to prevent hot air from the evaporator compartment from entering the air duct through the air inlet.

[0120] In one embodiment of the present invention, the refrigerator control method includes: when a first temperature difference is greater than a first preset temperature threshold, and / or a second temperature difference is greater than a second preset temperature threshold, confirming that the conditions for turning on the second fan are met.

[0121] In one embodiment of the present invention, the refrigerator control method further includes: when the second temperature difference is greater than the second preset temperature threshold and the evaporator temperature sampled at the current sampling time is greater than the third preset temperature threshold, confirming that the condition for the second fan to be turned on is met.

[0122] In one embodiment of the present invention, the refrigerator control method further includes: when the first temperature difference is greater than the first preset temperature threshold, the second temperature difference is greater than the second preset temperature threshold, and the evaporator temperature sampled at the current sampling time is greater than the third preset temperature threshold, confirming that the condition for the second fan to be turned on is met, wherein the second preset temperature threshold is greater than the third preset temperature threshold.

[0123] In one embodiment of the present invention, controlling the second fan to start includes: controlling the second fan to operate at a constant speed of a first preset speed.

[0124] In one embodiment of the present invention, when controlling the second fan to start, the method includes: dynamically controlling the speed of the second fan according to a preset speed control strategy.

[0125] 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 first temperature difference and the heating time of the defrosting heater, and the speed of the second fan is proportional to the first temperature difference and / or the heating 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.

[0126] 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 fourth preset temperature threshold; or, after the defrost heater stops operating, the evaporator temperature is greater than or equal to a fifth preset temperature threshold, wherein the fifth preset temperature threshold is greater than or equal to the fourth preset temperature threshold; or, 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.

[0127] In one embodiment of the present invention, before the defrost heater is turned on, the method 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 sixth preset temperature threshold, or when the shutdown time reaches a preset time.

[0128] According to the refrigerator control method of the present invention, when the defrosting heater is turned on, the evaporator temperature and the storage compartment temperature are acquired, and a first temperature difference between the two is calculated based on the evaporator temperature and the storage compartment temperature, and / or a second temperature difference is calculated between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time. Then, based on the first temperature difference and / or the second temperature difference, it is determined whether the conditions for turning on the second fan are met. After determining that the conditions for turning on the second fan are met, the second fan is controlled to turn on. This method can precisely control the timing of the second fan's activation based on the storage compartment temperature and the evaporator 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. Furthermore, based on this, the speed of the second fan is dynamically adjusted in conjunction with the timing of its opening or closing, so that the speed of the second fan can adapt to the heat changes in the air duct and match them with the heat changes in the air duct. This achieves more precise control of the heat circulation in the evaporator chamber, which not only improves defrosting efficiency but also effectively prevents hot air from entering the storage room through the air outlet.

[0129] 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.

[0130] 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 evaporator temperature; The second 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: When the defrosting heater is turned on, the evaporator temperature and the storage compartment temperature are obtained; The condition for the second fan to be turned on is determined based on the first temperature difference between the evaporator temperature and the storage room temperature, and / or the condition for the second fan to be turned on is determined based on the second temperature difference between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time. If it is determined that the conditions for starting the second fan are met, then the second fan is controlled to start.

2. The refrigerator according to claim 1, characterized in that, The controller is configured to: When the first temperature difference is greater than the first preset temperature threshold, and / or the second temperature difference is greater than the second preset temperature threshold, the condition for the second fan to be turned on is confirmed to be met.

3. The refrigerator according to claim 1, characterized in that, The controller is configured to: When the second temperature difference is greater than the second preset temperature threshold, and the evaporator temperature sampled at the current sampling time is greater than the third preset temperature threshold, it is confirmed that the conditions for the second fan to be turned on are met.

4. The refrigerator according to claim 1, characterized in that, The controller is configured to: When the first temperature difference is greater than the first preset temperature threshold, the second temperature difference is greater than the second preset temperature threshold, and the evaporator temperature sampled at the current sampling time is greater than the third preset temperature threshold, it is confirmed that the condition for the second fan to be turned on is met, wherein the second preset temperature threshold is greater than the third preset temperature threshold.

5. 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.

6. 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.

7. The refrigerator according to claim 6, characterized in that, 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 first temperature difference and the heating time of the defrosting heater to determine the rotational speed of the second fan, wherein the rotational speed of the second fan is directly proportional to the first temperature difference and / or the heating 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.

8. The refrigerator according to claim 1, characterized in that, 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 fourth preset temperature threshold; or... After the defrosting heater stops operating, the evaporator temperature is greater than or equal to the fifth preset temperature threshold, wherein the fifth preset temperature threshold is greater than or equal to the fourth 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.

9. 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 sixth preset temperature threshold, or when the shutdown time reaches a preset time, the defrosting heater is controlled to turn on.

10. A control method for a refrigerator as described in any one of claims 1-9, characterized in that, include: When the defrosting heater is turned on, the evaporator temperature and the storage compartment temperature are obtained; The condition for the second fan to be turned on is determined based on the first temperature difference between the evaporator temperature and the storage room temperature, or based on the second temperature difference between the evaporator temperature sampled at the current sampling time and the evaporator temperature sampled at the previous sampling time. If it is determined that the conditions for the second fan to be turned on are met, then the second fan is controlled to be turned on to prevent hot air from the evaporator compartment from entering the air duct through the air inlet.

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