Refrigerator and defrosting control method thereof

Abstract

The application relates to the technical field of refrigerators, and provides a refrigerator and a defrosting control method thereof. The refrigerator comprises a cabinet, an exhaust assembly, a double air door assembly, an evaporator assembly and a fan. An air duct cavity is formed with an upper air duct and a lower air duct. A partition plate is arranged in the cabinet. The exhaust assembly comprises first and second exhaust holes arranged on the partition plate, an exhaust channel for connecting the first exhaust hole and the lower air duct, and an air inlet valve assembly arranged between the second exhaust hole and the lower air duct. The double air door assembly comprises a first air door arranged between the upper air duct and the lower air duct, and a second air door arranged between the exhaust channel and the lower air duct. The refrigerator has a first defrosting mode and a second defrosting mode. In the second defrosting mode, only hot air in the external environment is used to continuously defrost the frost layer accumulated on the evaporator, and a defrosting heater does not need to be turned on, so that defrosting energy consumption is reduced. In the defrosting process, the hot air does not enter a storage compartment, temperature fluctuation in the storage compartment is reduced, and the preservation quality of food materials is improved.

Description

Technical Field

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

[0002] In conventional refrigerators, the airflow within the refrigeration duct is a closed loop, without any exchange with the outside air. When the fan is running, the air blown out enters the compartment through the refrigeration duct outlet, then passes through the return air vent and the evaporator before being drawn back in by the fan, completing the refrigeration cycle. After the refrigerator has been running for a period of time, frost will gradually build up on the evaporator surface, affecting refrigeration efficiency. When the frost layer reaches a certain level, the refrigerator needs to activate the defrost mode to defrost.

[0003] Current refrigerator defrosting rules are typically based solely on evaporator temperature and the number of times the refrigerator door is opened. Each defrost cycle consumes electricity to melt the frost on the evaporator, and the defrosting cycle is relatively short, placing a significant burden on the refrigerator's overall energy consumption. Furthermore, during defrosting, the frost layer on the evaporator melts as the temperature rises. During this process, hot air gradually rises and enters the freezer compartment through the air vents, causing a significant increase in the freezer temperature. This repeated freezing and thawing of food results in even more wasted energy in the defrosting mode. Summary of the Invention

[0004] The purpose of this application is to provide a refrigerator and its defrosting control method, which aims to solve the problems of existing refrigerators having short defrosting cycles and high energy consumption, and the fact that defrosting heat enters the compartment, causing temperature fluctuations in the compartment.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0006] In a first aspect, embodiments of this application provide a refrigerator, including a cabinet, an exhaust assembly, a dual-door assembly, an evaporator assembly, and a fan; the cabinet is provided with an air duct panel, and storage compartments and air duct cavities are formed on both sides of the air duct panel; the air duct cavity forms an upper air duct and a lower air duct, and the upper air duct and the lower air duct are respectively connected to the storage compartments; the cabinet is provided with a partition, the exhaust assembly includes a first exhaust hole and a second exhaust hole provided on the partition, an exhaust channel for connecting the first exhaust hole and the lower air duct, and an intake valve assembly provided between the second exhaust hole and the lower air duct; the dual-door assembly includes a first air duct provided between the upper air duct and the lower air duct, and a second air duct provided between the exhaust channel and the lower air duct; the evaporator assembly is provided in the lower air duct; the evaporator assembly includes an evaporator and a defrost heater for heating the evaporator; the fan is provided in the lower air duct and is used for airflow guidance.

[0007] In some embodiments, the exhaust assembly includes an air guide connector connected to the second damper and the partition, wherein the exhaust passage is formed within the air guide connector.

[0008] In some embodiments, the air guide connector is provided with a reinforcing rib structure within the exhaust channel.

[0009] In some embodiments, the first exhaust port is located diagonally above the second damper, the exhaust channel has an arc-shaped cross-section, the upper end of the exhaust channel is connected to the first exhaust port, and the lower end of the exhaust channel is connected to the second damper.

[0010] In some embodiments, the intake valve assembly includes an air guide pipe connecting the downdraft duct and the second exhaust port, and an intake valve disposed within the air guide pipe.

[0011] In some embodiments, the housing has an air supply vent between the upper end of the storage compartment and the upper air duct, and an air return vent between the lower end of the storage compartment and the lower air duct.

[0012] Secondly, this application provides a defrosting control method for the refrigerator, wherein in cooling mode, the first air damper is open, the second air damper is closed, and the air intake valve assembly is closed; the defrosting control method for the refrigerator includes the following steps:

[0013] Obtain the evaporator temperature T1 and determine whether the evaporator temperature T1 is higher than the first set temperature T0;

[0014] If T1 > T0, the refrigerator starts the first defrosting mode, the defrosting heater starts, the fan starts, the first air damper closes, the second air damper opens, and the air intake valve assembly opens;

[0015] If T1 < T0, the frost thickness D0 of the evaporator is obtained. According to the set first frost thickness D1, if D0 > D1, the refrigerator starts the second defrosting mode, the defrosting heater is not started, the first air damper is closed, the second air damper is opened, and the air intake valve assembly is opened; if D0 < D1, the refrigerator maintains the cooling mode.

[0016] In some embodiments, the step of the refrigerator starting the first defrosting mode when T1 > T0 includes: after the refrigerator starts the first defrosting mode, at a set interval t0, the frost layer thickness D0 of the evaporator is obtained, and it is determined whether the frost layer thickness is higher than the first frost layer thickness D1; ​​if D0 > D1, the first defrosting mode continues to run; if D0 < D1, the first defrosting mode ends and the refrigerator enters the cooling mode.

[0017] In some embodiments, after the refrigerator activates the second defrost mode for a preset working time t1 each time, the second defrost mode ends and the refrigerator enters the cooling mode.

[0018] In some embodiments, the step of the refrigerator activating the second defrosting mode when T1 < T0, D0 > D1 includes: determining whether the frost layer thickness D0 of the evaporator is lower than the second frost layer thickness D2 according to the set second frost layer thickness D2, D2 > D1; if D2 > D0 > D1, the refrigerator activates the second defrosting mode; if D0 > D2, the refrigerator activates the first defrosting mode.

[0019] The beneficial effects of the refrigerator and its defrosting control method of this application are as follows: The refrigerator has a first defrosting mode and a second defrosting mode; in the first defrosting mode, the defrosting heater heats the evaporator to defrost; and the fan can draw in air with a higher outside temperature, and the gas flowing through the evaporator can accelerate the dissolution of the frost layer, shorten the defrosting time, and effectively defrost the evaporator; in the second defrosting mode, the frost layer accumulated on the evaporator can be continuously defrosted using only the hot air from the outside, without turning on the defrosting heater; the frequency of starting the first defrosting mode of the refrigerator can be reduced, the usage time of the defrosting heater can be reduced, and the defrosting energy consumption can be greatly reduced.

[0020] Furthermore, in both the first and second defrosting modes, the first air damper is closed to isolate the upper and lower air ducts. The hot air from defrosting in the lower air duct will not enter the upper air duct, and therefore will not enter the storage room. This keeps the storage room at a low temperature, effectively preventing the hot air from the defrosting process from entering the storage room, reducing temperature fluctuations inside the storage room, and improving the freshness of the food. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A three-dimensional structural diagram of a refrigerator provided in an embodiment of this application;

[0023] Figure 2 A cross-sectional structural diagram of a refrigerator provided in an embodiment of this application;

[0024] Figure 3 A three-dimensional structural diagram showing the partition inside the refrigerator body according to an embodiment of this application;

[0025] Figure 4 for Figure 2A magnified view of part A in the middle;

[0026] Figure 5 for Figure 2 A magnified view of part B in the middle;

[0027] Figure 6 A three-dimensional structural diagram of the air guide connector and the double damper assembly provided in an embodiment of this application;

[0028] Figure 7 A flowchart illustrating the defrosting process of a refrigerator according to an embodiment of this application.

[0029] The following are the labeling elements in the figure:

[0030] 100. Box body;

[0031] 10. Storage room;

[0032] 20. Air duct cavity; 210. Upper air duct; 220. Lower air duct;

[0033] 30. Double damper assembly; 40. Evaporator; 50. Fan; 51. Fan shroud;

[0034] 1. Air duct panel; 2. Exhaust assembly; 3. Baffle; 4. First exhaust port; 5. Exhaust passage;

[0035] 6. First damper; 7. Second damper; 8. Air guide connector; 9. Reinforcing rib structure;

[0036] 11. Intake valve assembly; 111. Air guide pipe fittings; 112. Intake valve;

[0037] 12. Air supply vent; 13. Air return vent; 14. Second exhaust vent. Detailed Implementation

[0038] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0039] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0041] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0042] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0043] For ease of description, unless otherwise specified, the directions of up, down, left, right, front, and back in this article are based on the state of the refrigerator when it is in use. The refrigerator door is the front, the opposite direction is the back, and the vertical direction is the up and down direction.

[0044] Currently, refrigerator defrosting rules are typically determined simply by the evaporator temperature and the number of times the refrigerator door is opened. Each defrosting cycle consumes electricity to melt the frost on the evaporator, and the defrosting cycle is relatively short, placing a significant burden on the refrigerator's overall energy consumption. Furthermore, during defrosting, the frost layer on the evaporator melts as the temperature rises. During this process, hot air gradually rises and enters the freezer compartment through the air vents, causing a significant increase in the freezer temperature. This repeated freezing and thawing of food results in even more wasted energy in the defrosting mode.

[0045] Based on this, to solve the above problems, this application designs a refrigerator and its defrosting control method. The refrigerator has a first defrosting mode and a second defrosting mode. In the first defrosting mode, the defrosting heater heats the evaporator to defrost, and the fan can draw in high-temperature outside air. The air flowing through the evaporator can accelerate the dissolution of the frost layer. In the second defrosting mode, only the outside heat air is used to continuously defrost the frost layer accumulated on the evaporator, without turning on the defrosting heater. This reduces the frequency of starting the first defrosting mode, reduces the usage time of the defrosting heater, and greatly reduces defrosting energy consumption. Furthermore, in both the first and second defrosting modes, the hot air defrosting in the lower air duct will not enter the storage compartment, keeping the storage compartment at a low temperature, reducing temperature fluctuations inside the storage compartment, and improving the preservation quality of food.

[0046] refer to Figure 1 , Figure 2 and Figure 3 This application provides a refrigerator, including a cabinet 100, an air duct panel 1 inside the cabinet 100, and storage compartments 10 and air duct cavities 20 formed on both sides of the air duct panel 1. The air duct cavity 20 forms an upper air duct 210 and a lower air duct 220, and the upper air duct 210 and the lower air duct 220 are respectively connected to the storage compartments 10; an exhaust assembly 2, a partition 3 inside the cabinet 100, the exhaust assembly 2 including a first exhaust hole 4 and a second exhaust hole 14 provided on the partition 3, and a connection for communicating with the first exhaust hole. 4 and the exhaust passage 5 of the lower air duct 220; the intake valve assembly 11 located between the second exhaust port 14 and the lower air duct 220; the double damper assembly 30, including a first damper 6 located between the upper air duct 210 and the lower air duct 220, and a second damper 7 located between the exhaust passage 5 and the lower air duct 220; the evaporator assembly located in the lower air duct 220, the evaporator assembly including an evaporator 40 and a defrosting heater for heating the evaporator 40; and the fan 50 located in the lower air duct 220 and used for airflow guidance.

[0047] Understandably, the storage compartment 10 includes at least a refrigerator compartment and a freezer compartment, and some refrigerators also include a variable temperature compartment. In general, the refrigerator compartment, variable temperature compartment and freezer compartment are distributed from top to bottom. In this embodiment, they are uniformly referred to as storage compartment 10.

[0048] Specifically, when the refrigerator is turned on normally, it is in cooling mode. The evaporator 40 is used to cool the air in the lower air duct 220. The first air door 6 is in the open state to connect the upper air duct 210 and the lower air duct 220. The second air door 7 and the air intake valve assembly 11 are both in the closed state. The fan 50 is turned on and used to guide the cooled air from the lower air duct 220 to the upper air duct 210 and deliver it to the storage compartment 10 to cool down the storage compartment 10 and keep the food in the storage compartment 10 cool and fresh.

[0049] For example, refer to Figure 3 The partition 3 can be the back panel of the refrigerator, and the air duct cavity 20 is located behind the storage compartment 10, that is, between the refrigerator liner and the back panel; or the air duct cavity 20 can also be located on the left or right side of the storage compartment 10. This application embodiment does not specifically limit this.

[0050] In some embodiments, the evaporator 40 is part of the refrigerator's refrigeration system, which also includes the evaporator 40, a compressor, refrigerant, etc., for cooling the air inside the refrigerator body 100. The refrigerator also includes a control module (not shown), which is electrically connected to the refrigeration system, the dual-door assembly 30, the fan 50, and other components. The control module can control the refrigeration system and the fan 50 to operate, and the control system can also control the opening and closing of either the first door 6 or the second door 7.

[0051] In some embodiments, after the refrigerator has been running in cooling mode for a period of time, frost will form on the evaporator 40, causing frost to gradually form on the surface of the evaporator 40, which in turn affects the cooling efficiency; the air conditioner also has a defrosting mode to defrost the evaporator 40.

[0052] The refrigerator has a first defrosting mode. The control module opens the air intake valve assembly 11, closes the first air damper 6, and opens the second air damper 7. Subsequently, the upper air duct 210 and lower air duct 220 are not connected, and external air connects to the lower air duct 220 through the first exhaust port 4 and the second exhaust port 14. The control fan 50 and defrost heater (not shown) are turned on, and the defrost heater heats the evaporator 40 for defrosting. The fan 50 can draw in warmer outside air, which, after flowing through the evaporator 40, accelerates the dissolution of the frost layer, shortens the defrosting time, and effectively defrosts the evaporator 40. Simultaneously, the hot defrosting air is discharged into the lower air duct 220 through the exhaust channel 5 and the first exhaust port 4.

[0053] Understandably, in defrost mode, the first air door 6 is closed to isolate the upper air duct 210 from the lower air duct 220. The defrosting heat in the lower air duct 220 will not enter the upper air duct 210, and therefore will not enter the storage compartment 10, keeping the storage compartment 10 at a low temperature. This effectively prevents the heat from the defrosting process from entering the storage compartment 10, reduces temperature fluctuations inside the storage compartment 10, and improves the preservation quality of food.

[0054] refer to Figure 4 and Figure 6 In some embodiments, the exhaust assembly 2 includes an air guide connector 8 connected to the second damper 7 and the partition 3, and an exhaust passage 5 is formed in the air guide connector 8.

[0055] Understandably, the air guide connector 8 is disposed in the gap between the partition 3 and the air duct panel 1. One end of the air guide connector 8 is connected to the partition 3 and communicates with the first exhaust port 4 for air intake, while the other end of the air guide connector 8 is connected to the second damper 7. The air guide connector 8 has a hollow structure with open ends, thus forming an exhaust channel 5. When the second damper 7 is in the open state, the gas in the lower air duct 220 can flow through the exhaust channel 5 and be discharged through the first exhaust port 4.

[0056] Then, the exhaust channel 5 is formed by using the air guide connector 8, making reasonable use of the internal gap of the box 100, and the structural layout is reasonable and compact.

[0057] In some embodiments, the first exhaust port 4 is located diagonally above the second damper 7, the exhaust channel 5 has an arc-shaped cross-section, the upper end of the exhaust channel 5 is connected to the first exhaust port 4, and the lower end of the exhaust channel 5 is connected to the second damper 7.

[0058] Understandably, the gas in the downdraft duct 220 can be discharged through the exhaust channel 5 and the first exhaust port 4. The exhaust channel 5 is designed in an arc shape to reduce wind resistance and make the gas flow more smoothly. Moreover, the shape of the exhaust channel 5 matches the internal space of the housing 100, making the assembly structure more compact and stable.

[0059] refer to Figure 6 In some embodiments, the air guide connector 8 is provided with a reinforcing rib structure 9 in the exhaust channel 5.

[0060] Understandably, the foam layer of the refrigerator expands and fills the interior of the cabinet 100 during the foaming process, causing the air guide connector 8 to be subjected to stress. The air guide connector 8 is provided with a reinforcing rib structure 9, which can enhance the structural strength of the air guide connector 8 and prevent the air guide connector 8 from deforming under stress during the foaming process.

[0061] refer to Figure 2 In some embodiments, an air supply vent 12 is formed between the upper end of the storage compartment 10 and the upper air duct 210, and an air return vent 13 is formed between the lower end of the storage compartment 10 and the lower air duct 220.

[0062] Specifically, the upper end of the upper air duct 210 is connected to the storage compartment 10 through the air outlet 12, and the lower end of the lower air duct 220 is connected to the storage compartment 10 through the return air outlet 13. In the cooling mode, the cold air forms a circulating air duct between the lower air duct 220, the upper air duct 210, and the storage compartment 10, thus maintaining the cooling capacity of the storage compartment 10 and sustaining the cooling performance of the refrigerator.

[0063] refer to Figure 2 , Figure 3 and Figure 5Understandably, the second exhaust port 14 is located at the bottom of the partition 3 and below the first exhaust port 4; the second exhaust port 14 is used to allow outside air to enter the downdraft duct 220.

[0064] In some embodiments, the intake valve assembly 11 includes an air guide pipe 111 communicating between the downdraft 220 and the second exhaust port 14, and an intake valve 112 disposed within the air guide pipe 111.

[0065] Specifically, the air guide pipe 111 is disposed between the partition 3 and the lower air duct 220 to enable air intake communication between the second exhaust port 14 and the lower air duct 220; by controlling the opening or closing of the air intake valve 112, the air intake communication between the second exhaust port 14 and the lower air duct 220 can be controlled. The control module is electrically connected to the air intake valve 112 and can control the opening or closing of the air intake valve 112.

[0066] When the frost layer on the evaporator 40 reaches a certain level, the refrigerator starts the defrosting mode. The control module controls the air intake valve 112 to open, the first air damper 6 to close, and the second air damper 7 to open. Then, the upper air duct 210 and the lower air duct 220 are no longer connected. The outside air is connected to the lower air duct 220 through the first exhaust port 4 and the second exhaust port 14. The control fan 50 is turned on, and the fan 50 can draw in the outside air with a higher temperature. The gas flows through the second exhaust port 14 and the air guide pipe 111 into the lower air duct 220, which can accelerate the dissolution of the frost layer on the evaporator 40 and effectively defrost the evaporator 40. At the same time, the defrosting hot air is discharged from the lower air duct 220 through the exhaust channel 5 and the first exhaust port 4.

[0067] refer to Figure 2 In some embodiments, the fan 50 is positioned above the evaporator 40 in the downdraft duct 220.

[0068] Specifically, the fan 50 and the evaporator 40 are arranged from top to bottom in the lower air duct 220, making the overall assembly structure in the lower air duct 220 more compact and stable.

[0069] Furthermore, the fan 50 is also provided with a fan cover 51, which covers the fan 50. The lower end and the upper end of the fan cover 51 are respectively formed with an air inlet and an air outlet. The gas in the lower air duct 220 can flow through the fan through the air inlet of the fan cover 51 and out through the air outlet. In addition, the fan cover 51 not only protects the fan 50, but also guides the hot air entering the lower air duct 220, so that the gas can flow from bottom to top along the fan cover 51, thereby improving the flow stability of the hot air in the lower air duct 220.

[0070] In some embodiments, the defrosting heater may be located at the bottom or side of the evaporator, as long as it can defrost the frost layer on the evaporator.

[0071] This application provides a defrosting control method for a refrigerator. Figure 7 This is a schematic flowchart of an embodiment of the defrosting control method for a refrigerator provided in this application.

[0072] Based on the refrigerator described above, in one embodiment of this application, the defrosting control method for the refrigerator includes:

[0073] Get the evaporator temperature T1, and determine whether the evaporator temperature T1 is higher than the first set temperature T0. If T1>T0, control the refrigerator to start the first defrosting mode.

[0074] The first defrosting mode is activated as follows: the fan 50 is turned on normally, the control module controls the first damper 6 to close, the second damper 7 to open, the air inlet valve 112 to open, and the defrosting heater to start.

[0075] Specifically, the refrigerator has a temperature sensor at the evaporator 40, which can obtain the evaporator temperature T1 in real time.

[0076] Understandably, when excessive frost forms on the surface of the evaporator 40, the frost layer will form an insulating layer, hindering the heat exchange process of the evaporator 40 and impeding the flow and heat exchange of the refrigerant within the evaporator 40, causing the temperature of the evaporator 40 to rise. When the detected evaporator temperature T1 is greater than the first set temperature T0, it indicates that the temperature of the evaporator 40 is abnormal, and the frost layer will directly affect the operation of the evaporator 40, requiring defrosting of the evaporator 40; subsequently, the control module will receive a defrosting command to control the refrigerator to start the first defrosting mode.

[0077] The defrosting heater is energized to heat the evaporator 40 to achieve a defrosting effect. Furthermore, under the action of the fan 50, warmer outside air is drawn into the lower air duct 220 through the second exhaust port 14. The air flowing through the evaporator 40 accelerates the dissolution of the frost layer, effectively defrosting the evaporator 40, further shortening the defrosting cycle and achieving energy savings. The defrosting heat is discharged into the lower air duct 220 through the exhaust channel 5 and the first exhaust port 4, preventing the heat from entering the upper air duct 210 and the storage compartment 10. This keeps the storage compartment 10 at a low temperature even in the first defrosting mode, preventing the internal temperature of the storage compartment 10 from rising. This improves the preservation quality of food and further reduces energy consumption during the refrigerator's defrosting recovery process.

[0078] In some embodiments, after the refrigerator starts the first defrosting mode, it acquires the frost layer thickness D0 of the evaporator 40 at set intervals t0, and determines whether the frost layer thickness is lower than the preset first frost layer thickness D1; ​​if D1>D0, the first defrosting mode continues to be started; if D1<D0, the first defrosting mode ends, and the refrigerator resumes normal cooling mode.

[0079] Understandably, at each set interval t0, the frost thickness D0 of the evaporator 40 is detected and compared with the first frost thickness D1 to determine the defrosting process in real time. When the frost thickness D0 of the evaporator 40 is less than the first frost thickness D1, it indicates that the frost on the surface of the evaporator 40 has little impact on the cooling efficiency. Then, it is determined that the defrosting of the evaporator 40 is complete, thus ending the first defrosting mode. The control module then controls the refrigerator to start the cooling mode again, and controls the defrosting heater to stop, the first air damper 6 to open, the second air damper 7 to close, and the air inlet valve 112 to close, so that the air duct cavity 20 and the storage compartment 10 start the internal cooling circulation, providing normal cooling capacity to the storage compartment 10 and maintaining normal cooling performance.

[0080] Specifically, a thickness sensor for detecting the thickness of the evaporator 40 is provided in the downdraft duct 220; for example, the thickness sensor can be, but is not limited to, an ultrasonic thickness sensor, a laser thickness sensor, etc.

[0081] In some embodiments, the thickness of the first frost layer D1 ranges from 0.5 mm to 1.5 mm, and preferably, the thickness of the first frost layer D1 is set to 1 mm.

[0082] In the above embodiment, if the evaporator temperature T1 is less than the first set temperature T0, i.e., T1 < T0; the frost layer thickness D0 of the evaporator 40 is obtained, and according to the set first frost layer thickness D1, when D0 > D1, the refrigerator starts the second defrosting mode, the defrosting heater is not started, the first air door is closed, the second air door is opened, and the air intake valve assembly is opened.

[0083] Understandably, when T1 < T0 and the frost thickness D0 is greater than the set first frost thickness D1, it indicates that the frost thickness on the evaporator 40 has accumulated to a certain extent over time but has not reached the level required to activate the first defrosting mode. In this state, the defrosting heater is not activated, the lower air duct 220 is isolated from the upper air duct 210, and the lower air duct 220 is connected to the outside air. The fan 50 operates normally.

[0084] Understandably, in the second defrosting mode, only external heat is used to defrost the frost layer accumulated on the evaporator 40, achieving defrosting using natural heat sources without turning on the defrosting heater, thus achieving energy saving. At the same time, due to the design of the dual damper assembly 30, while allowing external air to defrost the evaporator 40, the lower air duct 220 and the upper air duct 210 are isolated from each other, avoiding the problem of the internal temperature of the storage compartment 10 rising.

[0085] In some embodiments, after the refrigerator has activated the second defrosting mode for a preset working time t1 each time, the second defrosting mode ends and the refrigerator enters the cooling mode.

[0086] Specifically, in the second defrosting mode, the refrigerator only runs for the set time t1. After the set time is reached, the refrigerator returns to the normal cooling mode. The first air door 6 opens, the second air door 7 closes, and the air inlet valve 112 closes, so that the air duct cavity 20 and the storage compartment 10 start the internal cooling circulation, providing normal cooling capacity to the storage compartment 10 and maintaining normal cooling performance.

[0087] In some embodiments, the preset working time t1 ranges from 2 to 8 minutes, and preferably, t1 is set to 5 minutes.

[0088] Specifically, the second defrost mode has a shorter runtime, minimizing the impact on the refrigerator's cooling performance while defrosting. Therefore, by repeatedly activating the second defrost mode, the refrigerator can continuously defrost the frost accumulated on the evaporator 40 without needing to activate the defrost heater, thus achieving energy savings. Furthermore, the second defrost mode reduces the thickness of the frost buildup on the evaporator 40, thereby extending the operating cycle of the first defrost mode. Through the second defrost mode, the refrigerator reduces the frequency of activating the first defrost mode and the duration of the defrost heater's operation, significantly reducing defrosting energy consumption and making the refrigerator more energy-efficient.

[0089] In some embodiments, based on the set second frost layer thickness D2, where D2 > D1; such as D0 > D2, the refrigerator activates the first defrosting mode.

[0090] Understandably, the second frost layer thickness D2 is greater than the first frost layer thickness D1. When the frost layer thickness D0 of the evaporator 40 accumulates to a larger thickness D2 over time, it indicates that the defrosting effect of the refrigerator in the second defrosting mode is insufficient. Therefore, the first defrosting mode is activated, the defrosting heater is started, and the evaporator 40 can be effectively defrosted, increasing the defrosting intensity.

[0091] In some embodiments, the thickness of the second frost layer, D2, ranges from 15 to 25 mm; preferably, D2 is set to 20 mm.

[0092] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A refrigerator, characterized in that, include: The box body has an air duct panel inside, and storage compartments and air duct cavities are formed on both sides of the air duct panel; the air duct cavity forms an upper air duct and a lower air duct, and the upper air duct and the lower air duct are respectively connected to the storage compartments; An exhaust assembly is provided inside the housing, the exhaust assembly includes a first exhaust port and a second exhaust port provided on the partition, an exhaust channel for connecting the first exhaust port and the downdraft duct, and an intake valve assembly provided between the second exhaust port and the downdraft duct; A dual damper assembly includes a first damper disposed between the upper air duct and the lower air duct, and a second damper disposed between the exhaust passage and the lower air duct; An evaporator assembly is located within the lower air duct; the evaporator assembly includes an evaporator and a defrost heater for heating the evaporator; A fan is installed in the downdraft duct and is used for airflow guidance.

2. The refrigerator according to claim 1, characterized in that, The exhaust assembly includes an air guide connector connected to the second damper and the partition, and the exhaust passage is formed within the air guide connector.

3. The refrigerator according to claim 2, characterized in that, The air guide connector has a reinforcing rib structure inside the exhaust channel.

4. The refrigerator according to any one of claims 1-3, characterized in that, The first exhaust port is located diagonally above the second damper. The exhaust channel has an arc-shaped cross-section. The upper end of the exhaust channel is connected to the first exhaust port, and the lower end of the exhaust channel is connected to the second damper.

5. The refrigerator according to claim 1, characterized in that, The intake valve assembly includes an air guide pipe connecting the lower air duct and the second exhaust port, and an intake valve disposed within the air guide pipe.

6. The refrigerator according to claim 1, characterized in that, An air inlet is formed between the upper end of the storage compartment and the upper air duct of the housing, and an air return inlet is formed between the lower end of the storage compartment and the lower air duct of the housing.

7. A defrosting control method for a refrigerator, based on the refrigerator according to any one of claims 1 to 6, characterized in that, In cooling mode, the first air damper is open, the second air damper is closed, and the air intake valve assembly is closed; the defrosting control method of the refrigerator includes the following steps: Obtain the evaporator temperature T1 and determine whether the evaporator temperature T1 is higher than the first set temperature T0; If T1 > T0, the refrigerator starts the first defrosting mode, the defrosting heater is activated, the first air damper is closed, the second air damper is opened, and the air intake valve assembly is opened; If T1 < T0, the frost thickness D0 of the evaporator is obtained. According to the set first frost thickness D1, if D0 > D1, the refrigerator starts the second defrosting mode, the defrosting heater is not started, the first air damper is closed, the second air damper is opened, and the air intake valve assembly is opened; if D0 < D1, the refrigerator maintains the cooling mode.

8. The defrosting control method for a refrigerator according to claim 7, characterized in that, In the step where T1 > T0, the refrigerator activates the first defrost mode, including: After the refrigerator starts the first defrosting mode, it acquires the frost thickness D0 of the evaporator at set intervals t0 and determines whether the frost thickness is higher than the first frost thickness D1. If D0 > D1, the first defrosting mode continues to run; if D0 < D1, the first defrosting mode ends and the refrigerator enters the cooling mode.

9. The defrosting control method for a refrigerator according to claim 7, characterized in that, After each time the refrigerator activates the second defrosting mode and reaches the preset working time t1, the second defrosting mode ends, and the refrigerator enters the cooling mode.

10. The defrosting control method for a refrigerator according to claim 7, characterized in that, In the step of starting the second defrost mode of the refrigerator, where T1 < T0 and D0 > D1, the following steps are included: Based on the set second frost layer thickness D2, where D2 > D1; determine whether the frost layer thickness D0 of the evaporator is lower than the second frost layer thickness D2; if D2 > D0 > D1, the refrigerator starts the second defrosting mode; if D0 > D2, the refrigerator starts the first defrosting mode.

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