Refrigerator and control method of heat blocking mechanism thereof

Abstract

This application discloses a refrigerator and its heat-blocking mechanism control method. A heat-blocking mechanism is installed outside the refrigeration compartment. This mechanism generates an airflow barrier by rotating to prevent the defrosting heat generated by the defrosting heater from entering the refrigeration compartment. Simultaneously, a vibration sensor is placed in the defrosting water discharge path of the evaporator to detect the vibration signal generated by the falling defrosting water droplets. The rate of defrosting water generation is quantified by the pulse change rate, thus reflecting the melting speed of the frost layer on the evaporator surface. Based on this, the start / stop and rotation speed of the heat-blocking mechanism are controlled. By detecting defrosting water, a direct product of the defrosting process, the real-time defrosting progress of the entire evaporator can be comprehensively and accurately determined. This achieves real-time precise matching between the rotation speed of the heat-blocking mechanism and the defrosting heat, effectively reducing room temperature rise and energy consumption. Furthermore, the vibration sensor's water flow detection has the characteristics of fast response and is not easily affected by airflow interference, which can improve the reliability and robustness of the controller's judgment.

Description

Technical Field

[0001] This application relates to the field of refrigeration equipment technology, and in particular to a refrigerator and a method for controlling its heat-insulating mechanism. Background Technology

[0002] When a refrigerator defrosts, the defrost heater heats the evaporator, melting the frost layer on its surface. However, the heat generated during defrosting can easily diffuse upwards into the freezer compartment and other cooling zones, causing the temperature in these zones to rise, affecting food storage quality and increasing subsequent cooling energy consumption. To prevent defrosting heat from entering the cooling zones, a heat-insulating mechanism is installed between the evaporator and the cooling zones to prevent this heat from entering.

[0003] In related technologies, the control of the heat-resistant mechanism mainly relies on temperature sensors. These sensors detect the temperature above the evaporator or inside the cooling room to determine the degree of defrosting, thereby controlling the start and stop of the heat-resistant mechanism. However, temperature sensors can only monitor the local temperature near their installation point and cannot accurately reflect the overall defrosting degree of the evaporator. This leads to inaccurate control of the start and stop timing of the heat-resistant mechanism, resulting in problems such as premature start-up causing energy waste or delayed shutdown causing defrosting heat to enter the cooling room. Furthermore, temperature sensors are susceptible to airflow interference and exhibit response lag, and the fixed settings of the heat-resistant mechanism cannot match the dynamic changes in defrosting heat during the defrosting process, making precise control difficult.

[0004] Therefore, it is necessary to optimize the control scheme of the refrigerator's heat insulation mechanism. Summary of the Invention

[0005] To address the aforementioned problems, this application provides a refrigerator, including a cabinet, an evaporator, a defrost heater, a heat-insulating mechanism, a vibration sensor, and a controller. The cabinet interior defines a cooling compartment. The evaporator is disposed outside the cooling compartment and provides cold air to it. The defrost heater is disposed on one side of the evaporator and provides defrosting heat to melt the frost layer on its surface. The heat-insulating mechanism is disposed between the evaporator and the cooling compartment and generates an airflow barrier by rotation to prevent the defrosting heat generated by the defrost heater from entering the cooling compartment. The vibration sensor is disposed in the defrost water discharge path of the evaporator and detects vibration signals generated by falling defrost water droplets. The vibration signal is a discrete pulse signal generated by the falling defrost water droplets impacting the vibration sensor.

[0006] The controller is electrically connected to the vibration sensor and the heat-resistant mechanism and is configured to perform the following: when the defrosting heater is started, the controller acquires the vibration signal detected by the vibration sensor and determines the pulse change rate based on the vibration signal. The pulse change rate is used to reflect the melting speed of the frost layer on the evaporator surface. The controller controls the start-up, shutdown, and rotation speed of the heat-resistant mechanism based on the pulse change rate, so that the rotation speed of the heat-resistant mechanism matches the melting speed of the frost layer on the evaporator surface.

[0007] Thus, in the above technical solution, by placing a vibration sensor in the defrost water discharge path of the evaporator, the vibration signal generated by the falling defrost water droplets is detected. The rate of defrost water generation is quantified by the pulse change rate, thereby reflecting the melting speed of the frost layer on the evaporator surface. Based on this, the start / stop and rotation speed of the heat-resistant mechanism are controlled. By detecting defrost water, a direct product of the defrosting process, the real-time defrosting progress of the entire evaporator can be comprehensively and accurately judged, achieving real-time precise matching between the rotation speed of the heat-resistant mechanism and the defrosting heat, thereby effectively reducing room temperature rise and energy consumption. Furthermore, the vibration sensor's water flow detection has the characteristics of fast response and is not easily affected by airflow interference, which can improve the reliability and robustness of the controller's judgment.

[0008] In some embodiments of this application, controlling the start-up, shutdown, and rotation speed of the heat-resistant mechanism according to the pulse change rate, so that the rotation speed of the heat-resistant mechanism matches the melting speed of the frost layer on the evaporator surface, includes: performing frequency conversion control on the heat-resistant mechanism according to the changing trend of the pulse change rate and a set threshold, so that the rotation speed of the heat-resistant mechanism increases as the melting speed of the frost layer on the evaporator surface increases and decreases as the melting speed of the frost layer on the evaporator surface decreases.

[0009] In the above technical solution, the heat-insulating mechanism is frequency-controlled according to the trend of pulse change rate and the set threshold, so that the rotation speed increases as the frost melting speed increases and decreases as the frost melting speed decreases, realizing real-time linkage between rotation speed and frost melting speed, so that the blocking effect provided by the heat-insulating mechanism is precisely matched with the current heat generation.

[0010] In some embodiments of this application, frequency conversion control of the heat-resistant mechanism is performed based on the changing trend of the pulse change rate and a set threshold, including: when the pulse change rate rises above a first threshold, starting the heat-resistant mechanism and controlling the rotation speed of the heat-resistant mechanism to increase at a constant rate of change; when the pulse change rate rises above a second threshold, controlling the rotation speed of the heat-resistant mechanism to increase non-uniformly based on the pulse change rate, wherein the second threshold is greater than the first threshold; when the pulse change rate falls below a third threshold, controlling the rotation speed of the heat-resistant mechanism to decrease exponentially based on an attenuation coefficient, wherein the third threshold is less than the second threshold; and when the pulse change rate falls below a fourth threshold, shutting down the heat-resistant mechanism, wherein the fourth threshold is less than the third threshold.

[0011] In the above technical solution, the defrosting stage is divided into four thresholds, and differentiated control is adopted for the physical characteristics of different defrosting stages. This allows the heat-insulating mechanism to start smoothly at the beginning of defrosting, produce a greater barrier effect at the peak stage, and smoothly transition to stop at the final stage, thus achieving precise adaptation to the dynamic changes in defrosting heat throughout the entire process.

[0012] In some embodiments of this application, controlling the rotational speed of the heat-resistant mechanism based on the non-uniform increase of the pulse change rate includes: taking the rotational speed of the heat-resistant mechanism when the pulse change rate rises to the second threshold as a first reference rotational speed, and controlling the rotational speed of the heat-resistant mechanism to be superimposed with a first adjustment amount on the basis of the first reference rotational speed, wherein the first adjustment amount increases non-uniformly with the increase of the pulse change rate.

[0013] In the above technical solution, considering that the defrosting heater power reaches its maximum during the peak defrosting period, the core of the frost layer melts extremely rapidly, and the defrosting water generation rate increases sharply, the defrosting heat generation reaches its peak and changes drastically. If a constant rate of change is used for frequency increase, the rotation speed will lag behind the heat generation, resulting in insufficient blocking effect. By using the real-time pulse rate of change as the variable for rotation speed adjustment, the increase in rotation speed is made proportional to the increase in the defrosting water generation rate. That is, the faster the frost layer melts and the more heat is generated, the faster the rotation speed of the heat-insulating mechanism increases, achieving a real-time dynamic and precise match between the blocking effect and the heat generation.

[0014] In some embodiments of this application, controlling the rotational speed of the heat-resistant mechanism to decrease exponentially based on an attenuation coefficient includes: taking the rotational speed of the heat-resistant mechanism when the pulse change rate decreases to the third threshold as a second reference rotational speed, and controlling the rotational speed of the heat-resistant mechanism to decrease exponentially over time from the second reference rotational speed.

[0015] In the above technical solution, considering that the defrosting heater has gradually stopped working at the end of the defrosting stage, the frost layer gradually thins until it is basically melted, and the defrost water production rate approaches zero, but at this time the temperature of the heat-blocking mechanism and the refrigeration compartment will still slowly rise. If the heat-blocking mechanism is stopped immediately, residual heat may sneak into the refrigeration compartment. If the high speed is maintained during the peak defrosting stage, it will cause unnecessary energy consumption. By adopting an exponential decay method to reduce the speed, the speed is reduced more quickly in the early stage to respond quickly to the trend of defrost water reduction and avoid excessive blocking. The speed is gradually reduced in the later stage to maintain a certain residual blocking effect and prevent residual heat from flowing back at the end of the defrosting stage. This achieves a smooth transition from effective blocking to complete shutdown, which not only ensures the stability of the refrigeration compartment temperature at the end of the defrosting stage, but also avoids temperature fluctuations and energy waste caused by sudden shutdown or linear speed reduction.

[0016] In some embodiments of this application, the method further includes: before the pulse change rate rises to the first threshold, if the start-up duration of the defrosting heater reaches a first duration or more, then activating the heat-resistant mechanism and controlling the rotation speed of the heat-resistant mechanism to increase at a constant rate of change; before the pulse change rate rises to the second threshold, if the start-up duration of the defrosting heater reaches a second duration or more, then controlling the rotation speed of the heat-resistant mechanism to increase non-uniformly based on the pulse change rate, wherein the second duration is longer than the first duration; before the pulse change rate falls to the third threshold, if the start-up duration of the defrosting heater reaches a third duration or more, then controlling the rotation speed of the heat-resistant mechanism to decrease exponentially based on an attenuation coefficient, wherein the third duration is longer than the second duration; before the pulse change rate falls to the fourth threshold, if the start-up duration of the defrosting heater reaches a fourth duration or more, then shutting down the heat-resistant mechanism, wherein the fourth duration is longer than the third duration.

[0017] In the above technical solution, by setting a time protection mechanism, the defrosting time is used as a backup judgment criterion when the vibration sensor is abnormal, ensuring that the controller can still complete the control function in the event of vibration sensor failure, which significantly improves the reliability and robustness of the system and avoids the loss of control of defrosting heat blockage caused by the failure of a single detection method.

[0018] In some embodiments of this application, the heat-resistant mechanism is a fan; controlling the start-up, shutdown, and rotation speed of the heat-resistant mechanism according to the pulse change rate, so that the rotation speed of the heat-resistant mechanism matches the melting speed of the frost layer on the evaporator surface, includes: controlling the upper limit of the rotation speed of the heat-resistant mechanism to be below 80% of its rated rotation speed.

[0019] In the above technical solution, by setting an upper limit of 80% of the rated speed, a 20% safety margin is reserved for the heat insulation mechanism. This not only meets the need for a large barrier effect during the peak defrosting period, but also avoids long-term overload operation of the motor, extends the service life of the heat insulation mechanism, and prevents the problems of sudden drop in efficiency and surge in noise at the limit speed.

[0020] In some embodiments of this application, a drainage system is also included, which includes a defrost water receiving part, a drain pipe, and a drainage collection structure. The defrost water receiving part is located at the bottom of the evaporator; the drain pipe is connected to the defrost water receiving part; the drainage collection structure is connected to the defrost water receiving part through the drain pipe, and the drainage collection structure is located above or inside the evaporating dish; wherein, the bottom of the drainage collection structure has an opening, and the vibration sensor is installed at a downward tilt at the opening and fixed to the bottom of the drainage collection structure.

[0021] In the above technical solution, considering that all the defrosting water generated by the evaporator needs to flow through the vibration sensor to ensure the integrity and accuracy of the detection, all the defrosting water at the bottom of the evaporator is collected through the defrosting water receiving part and introduced into the drainage collection structure through the drain pipe to be concentrated at the bottom opening, so that all the defrosting water drips down to impact the vibration sensor; at the same time, the vibration sensor is installed at a downward tilt so that the water droplets slide down the slope naturally after impact, avoiding water accumulation that would affect the accuracy of subsequent detection.

[0022] In some embodiments of this application, the drainage collection structure is funnel-shaped, wider at the top and narrower at the bottom, with its sidewalls extending upward from the edge of the opening to form an inner cavity for receiving defrost water. The bottom surface of the drainage collection structure is inclined relative to the horizontal plane. The vibration sensor is sealed at the opening and is sealed to the bottom surface of the drainage collection structure. The sidewall of the drainage collection structure has a drain outlet for discharging the defrost water flowing over the surface of the vibration sensor to the evaporation dish.

[0023] In the above technical solution, the funnel-shaped structure, wider at the top and narrower at the bottom, utilizes gravity to naturally collect defrost water, concentrating the water flow to the vibration sensor at the bottom opening, ensuring that all water droplets can be detected. The inclined bottom surface, combined with the side wall drain outlet, allows defrost water flowing over the vibration sensor surface to be promptly discharged to the evaporation dish under gravity, preventing water accumulation from interfering with detection. Furthermore, the vibration sensor is sealed to the bottom surface, preventing defrost water leakage from the opening, thus ensuring detection integrity and avoiding damage to electrical components from leakage.

[0024] In some embodiments of this application, the vibration sensor is a piezoelectric vibration sensor, including a piezoelectric wafer, an electrode layer, a base, and leads. The piezoelectric wafer is used to deform under the impact of defrosting water droplets. The electrode layer is disposed on the surface of the piezoelectric wafer and is used to draw out piezoelectric charges. The base is used to support and fix the piezoelectric wafer. The leads are connected to the electrode layer and are used to output the vibration signal. An inclined groove is provided on the outside of the evaporating dish, the groove extends upward at an incline, and the leads pass through the evaporating dish and through the groove.

[0025] In the above technical solution, an electrical signal is directly output based on the piezoelectric effect, requiring no external power supply. It features fast response speed, high sensitivity, and accurate capture of discrete water droplet impacts. Furthermore, the upward tilt of the cable tray utilizes the height difference and tilt angle to prevent defrosting water from flowing back along the lead wires to the electrical connection points, avoiding electrical faults such as short circuits and corrosion, while also standardizing the lead wire routing.

[0026] This application also provides a control method for a heat-blocking mechanism in a refrigerator. The heat-blocking mechanism generates an airflow barrier by rotating to prevent defrosting heat from entering the refrigeration compartment. The refrigerator includes a vibration sensor disposed in the defrosting water discharge path of the evaporator to detect vibration signals generated by falling defrosting water droplets. The vibration signal is a discrete pulse signal generated by the falling defrosting water droplets impacting the vibration sensor. The control method includes: when the defrosting heater is activated, acquiring the vibration signal detected by the vibration sensor and determining a pulse change rate based on the vibration signal. The pulse change rate reflects the melting speed of the frost layer on the evaporator surface. The starting, stopping, and rotation speed of the heat-blocking mechanism are controlled according to the pulse change rate to match the rotation speed of the heat-blocking mechanism with the melting speed of the frost layer on the evaporator surface.

[0027] In the above technical solution, a vibration sensor is placed in the defrost water discharge path of the evaporator to detect the vibration signal generated by the falling defrost water droplets. The rate of defrost water generation is quantified by the pulse change rate, thus reflecting the melting speed of the frost layer on the evaporator surface. Based on this, the start / stop and rotation speed of the heat-resistant mechanism are controlled. By detecting defrost water, a direct product of the defrosting process, the real-time defrosting progress of the entire evaporator can be comprehensively and accurately judged, achieving real-time precise matching between the rotation speed of the heat-resistant mechanism and the defrosting heat, thereby effectively reducing room temperature rise and energy consumption. Furthermore, the vibration sensor's water flow detection has the characteristics of fast response and is not easily affected by airflow interference, which can improve the reliability and robustness of the controller's judgment.

[0028] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0029] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the specification, serve to explain the principles of this application.

[0030] Figure 1 A schematic diagram of a refrigerator defrosting system according to an embodiment of this application is shown.

[0031] Figure 2 A schematic diagram of the structure of a piezoelectric vibration sensor according to an embodiment of this application is shown.

[0032] Figure 3 A schematic diagram of a refrigerator drainage system according to an embodiment of this application is shown.

[0033] Figure 4 It shows Figure 2 The diagram shows a sectional view of the refrigerator's drainage system.

[0034] Figure 5 It shows Figure 2 The diagram shows an exploded view of the refrigerator's drainage system.

[0035] Figure 6 A partial structural block diagram of a refrigerator according to an embodiment of this application is shown.

[0036] Figure 7 A control flowchart of a heat-insulating mechanism according to an embodiment of this application is shown.

[0037] Figure 8 It shows Figure 7 The flowchart showing a detailed embodiment of step S720 is shown.

[0038] Figure 9 It shows Figure 7 A detailed flowchart of another embodiment of step S720 is shown.

[0039] Figure 10 A control flowchart of a heat-insulating mechanism according to another embodiment of this application is shown.

[0040] The annotations in the attached figures are explained as follows: 1. Evaporator; 2. Defrosting heater; 3. Heat insulation mechanism; 31. Motor; 32. Impeller; 4. Vibration sensor; 41. Piezoelectric crystal; 42. Electrode layer; 43. Base; 44. Lead wire; 5. Controller; 6. Drainage system; 61. Defrosting water inlet; 62. Drain pipe; 63. Drainage collection structure; 631. Side wall; 632. Bottom surface; 633. Opening; 634. Inner cavity; 635. Drain outlet; 64. Evaporating dish; 65. Cable tray. Detailed Implementation

[0041] To make the objectives, implementation methods and advantages of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the described exemplary embodiments are only some embodiments of this application, and not all embodiments.

[0042] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0043] In the description of this application, it should be understood that the terms "inner", "outer", "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this application.

[0044] The terms "first," "second," "third," and "fourth" 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. Therefore, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0045] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0046] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0047] In related technologies, refrigerators suffer from inaccurate control of the start and stop timing of the heat-resistant mechanism. This is because the degree of defrosting is determined by detecting the temperature above the evaporator or inside the cooling compartment using a temperature sensor, which then controls the start and stop of the heat-resistant mechanism. However, the temperature sensor can only monitor the local temperature near its installation point and cannot accurately reflect the overall defrosting degree of the evaporator. Furthermore, the temperature sensor is susceptible to airflow interference and exhibits a response lag.

[0048] In view of this, this application designs a novel control logic for the heat-resistant mechanism. By placing a vibration sensor in the defrost water discharge path of the evaporator, it detects the vibration signal generated by the falling defrost water droplets. The rate of defrost water generation is quantified using the pulse change rate, thus reflecting the melting speed of the frost layer on the evaporator surface. Based on this, the start / stop and rotation speed of the heat-resistant mechanism are controlled. By detecting defrost water, a direct product of the defrosting process, the real-time defrosting progress of the entire evaporator can be comprehensively and accurately determined, achieving real-time precise matching between the rotation speed of the heat-resistant mechanism and the defrosting heat, thereby effectively reducing room temperature rise and energy consumption. Furthermore, the vibration sensor's water flow detection has the characteristics of fast response and is not easily affected by airflow interference, which can improve the reliability and robustness of the controller's judgment.

[0049] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0050] Figure 1 A schematic diagram of a refrigerator defrosting system according to an embodiment of this application is shown.

[0051] The refrigerator of this embodiment includes a cabinet (not shown in the figure), which serves as the supporting structure of the refrigerator and has an internal accommodating space (not shown in the figure). The accommodating space of the cabinet may house other components of the refrigerator, such as a refrigeration system, a defrosting system, a drainage system, and a circuit structure. The external shape of the cabinet can be designed as needed; for example, it can be a hollow cuboid shape.

[0052] The interior of the cabinet defines a refrigeration compartment, which provides space for storing items. The refrigeration compartment can be a freezer, a refrigerator, or a variable temperature compartment.

[0053] There can be multiple refrigeration compartments, which may include freezer and refrigerator compartments, and may further include a variable temperature compartment. Multiple refrigeration compartments allow for partitioned storage of items within the refrigerator, improving the user experience. These compartments can be arranged along the height of the refrigerator body or along its width.

[0054] The refrigerator of this embodiment also includes a refrigeration system for providing cold air to the refrigeration compartment. The refrigeration system includes a compressor, a condenser, a throttling device, an evaporator, and refrigeration piping. The compressor, condenser, throttling device, and evaporator are connected via the refrigeration piping. When the compressor operates, low-temperature, low-pressure refrigerant is drawn into the compressor and compressed into high-temperature, high-pressure superheated gas within the compressor cylinder before being discharged into the condenser. The high-temperature, high-pressure refrigerant gas dissipates heat through the condenser, its temperature continuously decreasing until it is gradually cooled into room-temperature, high-pressure saturated vapor, and further cooled into a saturated liquid. The pressure of the refrigerant remains almost constant throughout the condensation process. The throttling device throttles the high-pressure room-temperature liquid into low-temperature, low-pressure wet vapor, creating conditions for efficient heat absorption in the evaporator. The low-temperature, low-pressure refrigerant returns to the compressor after passing through the evaporator. This process is repeated, allowing the evaporator to continuously provide cold air to the refrigeration compartment, thereby maintaining the refrigeration compartment at the set temperature.

[0055] Evaporator 1 is located outside the refrigeration compartment, either inside an evaporator chamber at the back or top of the freezer compartment. Evaporator 1 includes fins and piping for refrigerant flow. The refrigerant evaporates and absorbs heat within the piping, supplying cool air to the refrigeration compartment through the fins, thus cooling the compartment. During operation, frost will gradually condense on the surface of evaporator 1. The accumulation of frost reduces heat exchange efficiency, therefore periodic defrosting is necessary.

[0056] To achieve defrosting of the evaporator 1, the refrigerator of this embodiment further includes a defrosting heater 2. The defrosting heater 2 is disposed on one side of the evaporator 1, for example, arranged at the bottom of the evaporator 1 or between the fins, and is thermally coupled to the pipes or fins of the evaporator 1.

[0057] The defrost heater 2 can be an electric heating wire. During defrosting, the defrost heater 2 is energized and generates heat, which is transferred to the surface of the evaporator 1, raising the temperature of the frost layer on the evaporator 1 above its melting point, causing the frost layer to melt and produce defrost water. The power of the defrost heater 2 can be set according to the refrigerator model and the size of the evaporator 1.

[0058] To prevent the heat generated by the defrost heater 2 from diffusing into the cooling compartment, the refrigerator of this embodiment further includes a heat-insulating mechanism 3. The heat-insulating mechanism 3 is disposed outside the cooling compartment, for example, above the evaporator 1, between the evaporator 1 and the air duct of the cooling compartment. The heat-insulating mechanism 3 is used to generate an airflow barrier by rotating to prevent the defrosting heat generated by the defrost heater 2 from entering the cooling compartment.

[0059] In some embodiments, such as Figure 1As shown, the heat-blocking mechanism 3 is a fan, which includes a motor 31 and an impeller 32. The motor 31 drives the impeller 32 to rotate, generating a downward airflow barrier to prevent the defrosting heat generated by the defrosting heater 2 from diffusing upward into the refrigeration compartment. The rotation speed of the heat-blocking mechanism 3 can be adjusted by the refrigerator controller 5. The higher the rotation speed of the heat-blocking mechanism 3, the greater the pressure of the generated airflow barrier, and the stronger the blocking effect on defrosting heat.

[0060] In some embodiments, the heat-insulating mechanism 3 employs a centrifugal fan, including a motor, an impeller, and a volute.

[0061] In some embodiments, the heat-insulating mechanism 3 employs an axial flow fan, including a motor, an impeller, and a guide vane. The impeller has axial blades that generate axial airflow when rotating, with the airflow direction perpendicular to the impeller plane. The guide vane is disposed around the impeller to guide the airflow downwards, forming an air curtain. The controller 5 achieves stepless adjustment of the axial flow fan speed by regulating the motor power supply frequency or voltage, thereby dynamically matching the blocking effect according to the pulse change rate.

[0062] To detect the melting rate of the frost layer on the surface of the evaporator 1, the refrigerator in this embodiment of the application further includes a vibration sensor 4. The vibration sensor 4 is disposed in the defrost water drainage path of the evaporator 1 and is used to detect the vibration signal generated by the falling defrost water droplets. The vibration signal is a discrete pulse signal generated by the falling defrost water droplets impacting the vibration sensor.

[0063] Figure 2 A schematic diagram of the structure of a piezoelectric vibration sensor according to an embodiment of this application is shown.

[0064] In some embodiments, such as Figure 2 As shown, the vibration sensor 4 is a piezoelectric vibration sensor, which includes a piezoelectric wafer 41, an electrode layer 42, a base 43, and leads 44. The piezoelectric wafer 41 can be made of piezoelectric ceramic material (such as PZT-5H) or quartz crystal, exhibiting a positive piezoelectric effect and generating charge under mechanical stress. The electrode layer 42 can be a conductive layer coated with silver paste or conductive adhesive on the surface of the piezoelectric wafer 41, used to draw out the piezoelectric charge. The base 43 can be a support structure made of metal or engineering plastic, used to fix the piezoelectric wafer 41 and install it in the drainage system 6. The leads 44 can be shielded wires, electrically connected to the electrode layer 42, transmitting the electrical signal generated by the piezoelectric wafer 41, i.e., the vibration signal, to the controller 5.

[0065] When defrost water droplets impact the piezoelectric wafer 41, the wafer 41 undergoes instantaneous deformation. Due to the piezoelectric effect, an electric charge is generated inside the piezoelectric wafer 41. The electrode layer 42 draws out the charge to form a transient voltage pulse, i.e., a vibration signal. The number of voltage pulses per unit time reflects the frequency of defrost water droplet falling, and the pulse change rate reflects the changing trend of the defrost water generation rate, i.e., the melting rate of the frost layer on the evaporator surface.

[0066] In some embodiments, the piezoelectric wafer 41 may also be made of PVDF (polyvinylidene fluoride) film. When the PVDF film is deformed by the impact of water droplets, the electrodes on the upper and lower surfaces generate charges to form a pulse signal. PVDF film has flexibility, water resistance and a high piezoelectric constant. It is highly impact-resistant and not easily broken, making it suitable for scenarios with severe vibration or limited installation space. It can be fitted to curved bases for installation.

[0067] The piezoelectric chip 41 deforms when impacted by water droplets and directly outputs an electrical signal based on the piezoelectric effect. It does not require external power supply, has a fast response speed and high sensitivity, and can accurately capture discrete water droplet impacts.

[0068] Figure 3 A schematic diagram of a refrigerator drainage system according to an embodiment of this application is shown. Figure 4 It shows Figure 2 The diagram shows a sectional view of a portion of the refrigerator's drainage system. Figure 5 It shows Figure 2 The diagram shows an exploded view of the refrigerator's drainage system.

[0069] In some embodiments, such as Figure 3 As shown, the refrigerator also includes a drainage system 6. The drainage system 6 includes a defrost water collection part 61, a drain pipe 62, a drain collection structure 63, and an evaporation dish 64.

[0070] The defrosting water collection part 61 is located at the bottom of the evaporator 1. It can be a water collection tray or water collection trough installed along the bottom edge of the evaporator 1 to collect defrosting water dripping from the surface of the evaporator 1 fins. The width of the defrosting water collection part 61 covers the entire bottom area of ​​the evaporator 1 to ensure that all defrosting water is collected and to avoid leakage.

[0071] The drain pipe 62 can be a plastic hose or a metal conduit, with its upper end connected to the outlet of the defrost water inlet 61 and its lower end connected to the drain collection structure 63. The drain pipe 62 can be flexible to adapt to the internal space layout of the refrigerator while ensuring smooth flow of defrost water.

[0072] The drainage collection structure 63 is connected to the defrosting water receiving part 61 via the drain pipe 62 and is located above or inside the evaporating dish 64.

[0073] In some embodiments, the drainage collection structure 63 is funnel-shaped, wider at the top and narrower at the bottom. This funnel-shaped structure utilizes gravity to naturally collect defrost water, concentrating the water flow to the bottom and helping to ensure that all water droplets are detected. The drainage collection structure 63 can be made of plastic or thin metal sheet.

[0074] In some embodiments, the drainage collection structure 63 is a straight cylindrical shape that runs vertically through the structure. The upper part is connected to the drain pipe 62, and the lower part is equipped with a vibration sensor 4. The inner wall of the straight cylindrical structure is smooth, which can reduce defrost water residue on the wall.

[0075] like Figures 3 to 5 As shown, the drainage collection structure 63 includes a sidewall 631, a bottom surface 632, and an opening 633. The sidewall 631 extends upward from the edge of the opening 633 to form an inner cavity 634 for receiving defrost water. The bottom of the sidewall 631 forms the bottom surface 632, which is inclined relative to the horizontal plane at an angle of, for example, 10° to 30°, so that the defrost water flows downward under the action of gravity.

[0076] In some embodiments, with Figure 4 Taking the angle shown as an example, the left side of the self-drainage collection structure 63 on the bottom surface 632 is inclined to the lower right side.

[0077] like Figure 4 As shown, the vibration sensor 4 is installed at a downward angle at the opening 633, sealingly fitting with the bottom surface 632. The upper surface of the piezoelectric wafer 41 faces the inner cavity 634 of the drainage collection structure 63, and is used to receive dripping defrost water. The base 43 is fixedly connected to the bottom surface 632 of the drainage collection structure 63, and can be installed by snap-fit, thread, or adhesive.

[0078] In some embodiments, with Figure 4 Taking the angle shown as an example, the left side of the self-drainage collection structure 63 on the bottom surface 632 is inclined to the lower right. Correspondingly, the vibration sensor 4 is inclined from the left side to the lower right.

[0079] In some embodiments, the size of the opening 633 may be slightly smaller than the size of the vibration sensor 4, so that the edge of the vibration sensor 4 overlaps the edge of the opening 633 to form a support structure.

[0080] In some embodiments, the sidewall 631 of the drainage collection structure 63 is provided with a drain outlet 635, which is located on one side of the bottom surface 632 in the inclined direction, and is used to guide the defrosting water flowing through the surface of the vibration sensor 4 to the evaporation dish 64.

[0081] In some embodiments, the position of the drain outlet 635 can be set to be higher than the opening 633 but lower than the upper edge of the drain collection structure 63, so as to ensure that the defrost water is discharged in time after a brief accumulation in the drain collection structure 63, while avoiding defrost water that has not contacted the vibration sensor 4 from overflowing directly from the drain outlet 635.

[0082] In some embodiments, such as Figure 3As shown, the drain outlet 635 extends upward through the upper edge of the drain collection structure 63 and downward through the lower edge of the drain collection structure 63. The vibration sensor 4 is installed at the lower edge of the drain collection structure 63 and covers the lower part of the drain outlet 635. After the defrosting water droplets entering the drain collection structure 63 fall onto the upper surface of the vibration sensor 4, they are discharged along the drain outlet 635 to the evaporating dish 64.

[0083] In some embodiments, with Figure 4 Taking the angle shown as an example, the bottom surface 632 is inclined from the left side to the lower right side of the drainage collection structure 63. Correspondingly, the vibration sensor 4 is inclined from the left side to the lower right side, and a drain outlet 635 is opened on the right side of the drainage collection structure 63 to facilitate the discharge of defrost water.

[0084] The evaporating dish 64 is used to receive defrost water discharged from the drain collection structure 63. The evaporating dish 64 can be a disc-shaped container made of metal or plastic. In some embodiments, the evaporating dish 64 is disposed in the compressor compartment at the bottom of the refrigerator, and the heat generated by the operation of the compressor is used to evaporate the defrost water, thereby achieving frost-free drainage.

[0085] In some embodiments, an inclined groove 65 is provided on the outside of the evaporating dish 64, extending upward at an angle. The groove 65 is a recess or an independent conduit used to accommodate the lead wire 44 of the vibration sensor 4. The lead wire 44 extends out of the evaporating dish 64 and passes through the groove 65, connecting to the controller 5.

[0086] The cable tray 65 is inclined upwards, and the height difference and inclination angle prevent defrosting water from flowing along the lead wire to the electrical connection part, avoiding electrical faults such as short circuits and corrosion, while also standardizing the routing of the lead wire 44.

[0087] Figure 6 A partial structural block diagram of a refrigerator according to an embodiment of this application is shown.

[0088] Controller 5 is the refrigerator's main control board or independent control module, including a processor, memory, and signal conditioning circuitry. For example... Figure 6As shown, controller 5 is electrically connected to vibration sensor 4. It can acquire the vibration signal detected by vibration sensor 4, amplify and filter it after signal conditioning circuitry, count the number of pulses per unit time, and calculate the pulse change rate. Controller 5 is electrically connected to heat-resistant mechanism 3. It can send control signals to heat-resistant mechanism 3 according to the calculated pulse change rate to control the start, stop, and speed of heat-resistant mechanism 3. Controller 5 can also be electrically connected to defrost heater 2. It can send control signals to defrost heater 2 to control the start, stop, and heating power of defrost heater 2. Controller 5 can also be electrically connected to compressor. It can send control signals to compressor to control compressor start-up or compressor stop-up, thereby maintaining the temperature inside the refrigeration compartment at the set temperature through compressor start-up and stop-up. Controller 5 can also be connected to other electronic control devices in the refrigerator to realize a series of control processes of the refrigerator.

[0089] Controller 5 is configured to execute the heat-resistant mechanism control program, such as Figure 7 As shown, the heat-insulating mechanism control program includes at least steps S710 to S720, which are described in detail below.

[0090] In step S710, after the defrosting heater is started, the vibration signal detected by the vibration sensor is acquired, and the pulse change rate is determined based on the vibration signal.

[0091] The pulse change rate is used to reflect the melting speed of the frost layer on the evaporator surface. Specifically, defrost water droplets impact the piezoelectric crystal of the piezoelectric vibration sensor, causing the crystal to deform and output discrete voltage pulse signals under the piezoelectric effect. The controller acquires this signal at a fixed sampling frequency, amplifies, filters, and performs threshold comparison to identify valid pulses, and counts the number of pulses within a unit time period. Then, it calculates the ratio of the difference in the number of pulses between adjacent time periods to the time period length, which yields the pulse change rate. This pulse change rate reflects the rate of defrost water generation, and thus the melting speed of the frost layer on the evaporator surface.

[0092] In step S720, the start-up, shutdown and rotation speed of the heat-resistant mechanism are controlled according to the pulse change rate, so that the rotation speed of the heat-resistant mechanism matches the melting speed of the frost layer on the evaporator surface.

[0093] The pulse change rate directly reflects the melting speed of the frost layer on the evaporator surface. The faster the melting speed, the greater the amount of defrosting heat generated. Based on this, the controller controls the start and stop of the heat-blocking mechanism and adjusts the speed of the heat-blocking mechanism in real time. When the frost layer melts rapidly, the heat-blocking mechanism operates at high speed to generate a stronger airflow barrier to prevent defrosting heat from entering the refrigeration compartment. When the frost layer melts slowly, it operates at low speed or stops to avoid energy waste caused by excessive barrier. This achieves a dynamic balance between the barrier effect and the amount of defrosting heat generated.

[0094] In some embodiments, controlling the start-up, shutdown, and rotation speed of the heat-resistant mechanism according to the pulse change rate, so that the rotation speed of the heat-resistant mechanism matches the melting speed of the frost layer on the evaporator surface, includes: performing frequency conversion control on the heat-resistant mechanism according to the changing trend of the pulse change rate and a set threshold, so that the rotation speed of the heat-resistant mechanism increases as the melting speed of the frost layer on the evaporator surface increases and decreases as the melting speed of the frost layer on the evaporator surface decreases.

[0095] By monitoring the rising or falling trend of the pulse change rate, the direction of change in the frost melting rate on the evaporator surface is determined. Based on this, and according to the relationship between the pulse change rate and a set threshold, the speed of the heat-resistant mechanism is continuously adjusted. The rotation speed of the heat-resistant mechanism increases as the frost melting rate increases and decreases as the frost melting rate decreases. This achieves real-time linkage between the rotation speed of the heat-resistant mechanism and the frost melting rate, ensuring that the barrier effect provided by the heat-resistant mechanism is precisely matched with the current defrosting heat. This avoids both the increased fan energy consumption due to "excessive barrier" and the heat intrusion into the cooling compartment caused by "insufficient barrier," significantly improving control accuracy and energy efficiency.

[0096] In some embodiments, setting the threshold includes a first threshold, a second threshold, a third threshold, and a fourth threshold. For example... Figure 8 As shown, according to the changing trend of the pulse change rate and the set threshold, the frequency conversion control of the heat insulation mechanism includes at least the following steps S810 to S880, which are described in detail below.

[0097] In step S810, it is determined whether the pulse change rate has risen above the first threshold. If so, step S820 is executed.

[0098] In step S820, the heat-insulating mechanism is activated, and the rotation speed of the heat-insulating mechanism is controlled to increase at a constant rate of change.

[0099] In some embodiments, when the pulse change rate rises above a first threshold, the heat-resistant mechanism is activated and operates at an initial speed R0. Subsequently, the speed of the heat-resistant mechanism is controlled to increase uniformly over time at a constant change rate m. Specifically, the speed R0 during the t-th time period at the beginning of the defrosting phase... t The initial rotational speed R0, constant rate of change m, and time period number t are jointly determined. The time period number t is an integer count within the defrosting start stage (such as 0, 1, 2, etc.). The rotational speed increases linearly with the time period until the pulse rate of change rises to the second threshold, at which point it switches to the next stage.

[0100] For example, according to relation R t =R0+m×t 0-a Determine the fan speed during the t-th time period at the beginning of the defrosting phase; where R tLet R0 be the initial fan speed during the t-th time interval of the defrosting phase, m be a positive constant, and a be the time interval (integer, e.g., 1 min, 2 min, 3 min, ...). 0-a This is the t-th time period in the initial stage of defrosting, i.e., the time period number, which is an integer, such as 0, 1, 2, ...

[0101] In the initial stage of defrosting, the bonding layer between the frost layer and the pipe wall melts first, and the overall thickness of the frost layer decreases very slowly. The defrosting water generation rate is low and changes gradually. At this time, a constant rate of change m is used to uniformly increase the rotation speed, so that the heat-insulating mechanism can start smoothly from a static state and gradually establish an airflow barrier, avoiding motor impact and airflow disturbance caused by sudden changes in rotation speed. At the same time, the linearly increasing rotation speed is adapted to the slow and uniform frost melting characteristics in the initial stage of defrosting. This not only establishes an effective barrier in advance as the defrosting heat generation gradually increases, preventing heat intrusion, but also avoids energy waste caused by high-speed operation in the initial stage of defrosting, thus achieving a balance between barrier effect and energy consumption control.

[0102] In step S830, it is determined whether the pulse change rate has risen above the second threshold. If so, step S840 is executed.

[0103] The second threshold is greater than the first threshold.

[0104] In step S840, the rotational speed of the heat-insulating mechanism is controlled based on the non-uniform increase of the pulse change rate.

[0105] In some embodiments, when the pulse change rate rises above a second threshold, the rotational speed of the heat-insulating mechanism is controlled to increase non-uniformly based on the pulse change rate, including: taking the rotational speed of the heat-insulating mechanism when the pulse change rate rises to the second threshold as a first reference rotational speed, and controlling the rotational speed of the heat-insulating mechanism to be superimposed on the first reference rotational speed. The first adjustment amount increases non-uniformly with the increase of the pulse change rate, that is, the larger the pulse change rate, the faster the rotational speed increases.

[0106] Specifically, the rotation speed of the t-th time period during the peak defrosting phase is determined by the first reference rotation speed, the real-time pulse change rate, and the time period number. The time period number t is an integer count within the peak defrosting phase. The rotation speed is adjusted in real time according to the dynamic change of the pulse change rate until the pulse change rate drops to the third threshold, at which point the system switches to the next phase.

[0107] For example, according to relation R t =R t1 +K t ×t a-b Determine the fan speed during the t-th time period of the peak defrosting phase; where R t R represents the fan speed during the t-th time period of the peak defrosting phase. t1t is the rotational speed of the heat-resistant mechanism when the pulse rate of change rises to the second threshold. a-b This refers to the t-th time period during the peak defrosting phase, i.e., the time period number, which is an integer, such as 0, 1, 2, ... During peak defrosting periods, the defrost heater reaches its maximum power, causing rapid melting of the frost core and a sharp increase in defrost water generation. At this point, defrost heat generation reaches its peak and fluctuates dramatically. Continuing to use a constant rate of change for frequency increase would result in the rotational speed lagging behind heat generation, leading to insufficient insulation. By using the real-time pulse rate of change as the variable for rotational speed adjustment, the increase in rotational speed is made proportional to the increase in defrost water generation rate. That is, the faster the frost melts and the more heat is generated, the more rapidly the rotational speed of the heat-insulating mechanism increases, achieving a real-time, dynamic, and precise match between insulation effect and heat generation.

[0108] In step S850, it is determined whether the pulse change rate has dropped below the third threshold. If so, step S860 is executed.

[0109] The third threshold is less than the second threshold.

[0110] In step S860, the rotational speed of the heat-insulating mechanism is reduced exponentially based on the attenuation coefficient.

[0111] In some embodiments, when the pulse rate of change drops below a third threshold, the rotational speed of the heat-resistant mechanism is controlled to decrease exponentially based on an attenuation coefficient. This includes: using the rotational speed of the heat-resistant mechanism when the pulse rate of change drops to the third threshold as a second reference rotational speed, and controlling the rotational speed of the heat-resistant mechanism to decrease exponentially over time from the second reference rotational speed. That is, the rotational speed decreases rapidly in the early stage and gradually slows down in the later stage.

[0112] Specifically, the rotational speed of the t-th time period at the end of the defrosting stage is determined by the second reference rotational speed, the attenuation coefficient, and the time period number. The attenuation coefficient is a positive constant used to limit the rate of exponential decay. The time period number t is an integer count within the end of the defrosting stage, until the pulse change rate drops to the fourth threshold and the heat-resistant mechanism is shut down.

[0113] For example, according to relation R t = R t2 ×e^(-p×t b-c Determine the fan speed during the t-th time period at the end of the defrosting phase; where R t R represents the fan speed during the t-th time period at the end of the defrosting phase. t2 t represents the rotational speed of the heat-resistant mechanism when the pulse rate of change drops to the third threshold, p is the attenuation coefficient, which is a positive constant; b-c Let t be the t-th time period in the end stage of defrosting, and take an integer value, such as 0, 1, 2, ...

[0114] During the final stage of defrosting, the defrosting heater gradually stops working, the frost layer gradually thins until it is almost completely melted, and the defrost water production rate approaches zero. However, at this time, the temperature of the heat-insulating mechanism and the cooling compartment will still slowly rise. If the heat-insulating mechanism is stopped immediately, residual heat may sneak into the cooling compartment. If the high speed during the peak defrosting stage is maintained, unnecessary energy consumption will occur. An exponential decay method is used to reduce the speed. The speed is reduced more quickly in the early stage to respond quickly to the trend of decreasing defrost water and avoid excessive blocking. The speed is gradually reduced in the later stage to maintain a certain residual blocking effect and prevent residual heat from flowing back in the final stage of defrosting. This achieves a smooth transition from effective blocking to complete shutdown, which not only ensures the stability of the cooling compartment temperature during the final stage of defrosting but also avoids temperature fluctuations and energy waste caused by sudden shutdown or linear speed reduction.

[0115] In step S870, it is determined whether the pulse change rate has dropped below the fourth threshold. If so, step S880 is executed.

[0116] The fourth threshold is less than the third threshold.

[0117] In step S880, the heat-insulating mechanism is shut down.

[0118] During defrosting, the rate of frost melting is not linear. In the initial stage of defrosting, the layer of frost in contact with the evaporator tube wall melts slowly. During this period, the defrosting heater power gradually increases, and the amount of defrost water produced gradually increases. At the peak of defrosting, the defrosting heater power reaches its maximum, the core of the frost begins to melt, and the frost thickness decreases rapidly. At this point, a large amount of heat accumulates around the heat-resistant mechanism, requiring the mechanism to rotate at a higher speed to create a greater barrier effect and prevent heat from entering the refrigerated compartment. In the final stage of defrosting, the defrosting heater gradually resumes operation, the frost layer thins, and the amount of defrost water produced gradually decreases.

[0119] After defrosting is initiated, when the pulse rate of change rises above the first threshold, the heat-blocking mechanism is activated, and its rotation speed is increased at a constant rate. When the pulse rate of change further rises above the second threshold, the rotation speed of the heat-blocking mechanism is increased non-uniformly based on the pulse rate of change. When the pulse rate of change decreases and falls below the third threshold, the rotation speed of the heat-blocking mechanism is reduced exponentially based on the attenuation coefficient. When the pulse rate of change further decreases below the fourth threshold, the heat-blocking mechanism is shut down. By dividing the defrosting stages into four thresholds, differentiated control is adopted for the physical characteristics of different defrosting stages. This ensures that the heat-blocking mechanism starts smoothly at the beginning of defrosting, produces a greater blocking effect during the peak stage, and smoothly transitions to a stop in the final stage, achieving precise adaptation to the dynamic changes in defrosting heat throughout the entire process.

[0120] Understandably, the first threshold, second threshold, third threshold, and fourth threshold can be preset pulse change rate values. Their specific values ​​are comprehensively calibrated based on factors such as the structural dimensions of the evaporator, the power of the defrost heater, the rated speed of the heat insulation mechanism, and the ambient temperature and humidity of the refrigerator, so as to ensure that the switching timing of each defrost stage matches the actual situation of the defrost physical process.

[0121] To prevent malfunctions of the piezoelectric vibration sensor from affecting the precise control of the heat-resistant mechanism, a time protection mechanism is implemented in some embodiments. If the defrosting heater's startup duration exceeds a first duration before the pulse change rate rises to a first threshold, the heat-resistant mechanism is activated, and its rotational speed is increased at a constant rate. If the defrosting heater's startup duration exceeds a second duration before the pulse change rate rises to a second threshold, the heat-resistant mechanism's rotational speed is increased non-uniformly based on the pulse change rate, with the second duration exceeding the first duration. If the defrosting heater's startup duration exceeds a third duration before the pulse change rate falls to a third threshold, the heat-resistant mechanism's rotational speed is decreased exponentially based on an attenuation coefficient, with the third duration exceeding the second duration. If the defrosting heater's startup duration exceeds a fourth duration before the pulse change rate falls to a fourth threshold, the heat-resistant mechanism is shut down, with the fourth duration exceeding the third duration.

[0122] If the pulse change rate does not reach the set threshold but the defrosting heater continues to operate for the corresponding duration, the defrosting stage will be forcibly switched or the heat-blocking mechanism will be shut down. Vibration sensors may fail to detect faults due to malfunctions, icing, or abnormal water droplet distribution. If control is solely based on the pulse change rate, the heat-blocking mechanism may fail to start, the defrosting stage may fail to switch, or the system may continue operating after defrosting has ended. By setting a time protection mechanism, the defrosting duration is used as a backup criterion when the vibration sensor malfunctions. This ensures that the controller can still perform its control functions even if the vibration sensor fails, significantly improving the system's reliability and robustness, and preventing uncontrolled defrosting heat blockage due to a single detection method failure.

[0123] Understandably, the first, second, third, and fourth durations can be preset duration values. Their specific values ​​are comprehensively calibrated based on factors such as the structural dimensions of the evaporator, the power of the defrosting heater, the distribution pattern of the frost layer thickness, and historical defrosting data. This ensures that when the vibration sensor detects an abnormality or the pulse change rate does not reach the threshold, the heat-resistant mechanism can still complete the stage switching or safely shut down according to the preset sequence, thus avoiding the defrosting process from getting out of control.

[0124] In some embodiments, such as Figure 9 As shown, according to the changing trend of the pulse change rate and the set threshold, the frequency conversion control of the heat insulation mechanism includes at least the following steps S910 to S9120, which are described in detail below.

[0125] In step S910, it is determined whether the pulse change rate has risen above the first threshold. If so, step S930 is executed; otherwise, step S920 is executed.

[0126] In step S920, it is determined whether the start-up duration of the defrosting heater has reached or exceeded the first duration. If so, step S930 is executed; otherwise, step S910 is returned.

[0127] In step S930, the heat-insulating mechanism is activated, and its rotation speed is controlled to increase at a constant rate of change. Then, step S940 is executed.

[0128] In step S940, it is determined whether the pulse change rate has risen above the second threshold. If so, step S960 is executed; otherwise, step S950 is executed.

[0129] The second threshold is greater than the first threshold.

[0130] In step S950, it is determined whether the start-up duration of the defrosting heater has reached or exceeded the second duration. If so, step S960 is executed; otherwise, step S940 is returned.

[0131] The second duration is longer than the first duration.

[0132] In step S960, the rotational speed of the heat-insulating mechanism is controlled by a non-uniform increase in the pulse rate of change. Then, step S970 is executed.

[0133] In step S970, it is determined whether the pulse change rate has dropped below the third threshold. If so, step S990 is executed; otherwise, step S980 is executed.

[0134] The third threshold is less than the second threshold.

[0135] In step S980, it is determined whether the start-up duration of the defrosting heater has reached more than the third duration. If so, step S990 is executed; otherwise, step S970 is returned.

[0136] The third duration is longer than the second duration.

[0137] In step S990, the rotational speed of the heat-insulating mechanism is reduced exponentially based on the attenuation coefficient. Then, step S9100 is executed.

[0138] In step S9100, it is determined whether the pulse change rate has dropped below the fourth threshold. If so, step S9120 is executed; otherwise, step S9110 is executed.

[0139] The fourth threshold is less than the third threshold.

[0140] In step S9110, it is determined whether the start-up duration of the defrosting heater has reached the fourth duration or more. If so, step S9120 is executed; otherwise, step S9100 is returned.

[0141] The fourth duration is longer than the third duration.

[0142] In step S9120, the heat-insulating mechanism is shut down.

[0143] In some embodiments, controlling the start-up, shutdown, and rotation speed of the heat-resistant mechanism based on the pulse change rate to match the melting rate of the frost layer on the evaporator surface includes controlling the upper limit of the rotation speed of the heat-resistant mechanism to be below 80% of its rated speed. That is, regardless of the amount of defrosting heat generated as indicated by the pulse change rate, the heat-resistant mechanism operates at a safe speed not exceeding 80% of its rated speed.

[0144] During peak defrosting periods, the frost layer melts rapidly, and the pulse rate of change may remain consistently high. If the rotational speed is increased without limit based solely on the pulse rate of change, the heat-resistant mechanism will operate under extreme conditions for an extended period, leading to motor overheating, accelerated bearing wear, and increased mechanical vibration. In severe cases, this could result in motor burnout or impeller breakage. By setting an upper limit of 80% of the rated speed, a 20% safety margin is provided for the heat-resistant mechanism. This satisfies the need for high insulation during peak defrosting periods while preventing prolonged motor overload, extending the service life of the heat-resistant mechanism, and preventing sudden efficiency drops and noise spikes at extreme speeds.

[0145] Figure 10 A control flowchart of a heat-insulating mechanism according to another embodiment of this application is shown. Figure 10 As shown, the heat-insulating mechanism control program includes at least steps S1010 to S1070, which are described in detail below.

[0146] In step S1010, defrosting is initiated.

[0147] In other words, the controller receives a defrost command and initiates the defrost program. The defrost command can be determined based on factors such as the evaporator's running time, the thickness of the frost layer on the evaporator, or the specific operating conditions of the refrigerator.

[0148] In step S1020, the defrosting heater starts working.

[0149] That is, the controller starts the defrosting heater, and the power of the defrosting heater gradually increases, providing defrosting heat to the evaporator to melt the frost layer on its surface.

[0150] In step S1030, the defrosting begins.

[0151] During the initial defrosting stage, the power of the defrosting heater gradually increases. At this time, the layer of frost that is in contact with the evaporator tube wall melts first, and the overall thickness of the frost layer decreases very slowly. The defrosting water generated drips down the surface of the evaporator fins, collects in the defrosting water collection part, and flows into the drainage collection structure through the drain pipe, impacting the vibration sensor and generating a vibration signal.

[0152] The controller acquires the vibration signal detected by the vibration sensor, records the pulse signal and corresponding time, and simultaneously counts the total number of pulses P generated by the vibration sensor at each time interval 'a'. The pulse change rate K at the t-th time interval is used as the input. t This reflects the rate of frost melting during the t-th time period. During this stage, there are fewer water droplets, lower pressure, and slower changes in pressure. K t Low and tending to a constant.

[0153] Pulse change rate K t The calculation formula is: K t =(P t -P t-1 ) / a; where P t Let P be the total number of pulses in the t-th time period. t-1 Let be the total number of pulses in the (t-1)th time period, and 'a' be the time interval.

[0154] When K t When the speed rises above the first threshold C0, the controller activates the heat-resistant mechanism with an initial speed of R0. To prevent the activation of the heat-resistant mechanism from being affected by a malfunctioning vibration sensor, the controller simultaneously records the activation duration Time of the defrosting heater. If K... t If the temperature does not rise to C0 but the time reaches or exceeds the first duration L0, the heat-blocking mechanism will be forcibly activated.

[0155] During this stage, the frost melts slowly and evenly, and the controller regulates the rotation speed of the heat-insulating mechanism at a constant rate of change m with uniform frequency adjustment. The rotation speed R in the t-th time period... t For: R t =R0+m×t 0-a Where m is a positive constant, R0 is the initial rotational speed of the heat-resistant mechanism, a is the time interval (rounded to an integer, such as 1 min, 2 min, 3 min, etc.), and t is the rotational speed of the heat-resistant mechanism. 0-a This refers to the t-th time period in the initial stage of defrosting (take an integer, such as 0, 1, 2, etc.).

[0156] When K t When the temperature rises above the second threshold C1, the defrosting initiation phase ends, and the heat-insulating mechanism reaches its maximum rotational speed R during this phase. t1 To avoid affecting the control of the heat insulation mechanism if the vibration sensor malfunctions, if K t If the time does not rise to C1 but reaches the second duration L1 or higher, then a forced switch to the next stage will be initiated.

[0157] In step S1040, the peak defrosting stage.

[0158] During peak defrosting, the defrost heater reaches its maximum power, the core of the frost layer begins to melt, and the frost layer thickness decreases rapidly. At this time, a large amount of heat accumulates around the heat-insulating mechanism, which needs to generate greater pressure through faster rotation to prevent heat from entering the cooling compartment.

[0159] During this stage, the frost layer melts rapidly, and the controller controls the rotation speed of the heat-resistant mechanism at a pulse change rate K. t Non-uniform frequency ramping is used to regulate the change. The rotational speed R in the t-th time period... t For: R t =R t1 +K t ×t a-b Among them, R t1 For K t The rotational speed of the heat-resistant mechanism when it rises to the second threshold C1, t a-b This refers to the t-th time period during the peak defrosting phase (take an integer, such as 0, 1, 2, etc.).

[0160] When K t When the temperature drops below the third threshold C2, the peak defrosting phase ends, and the heat-insulating mechanism reaches its maximum rotational speed R during this phase. t2 To avoid affecting the control of the heat insulation mechanism if the vibration sensor malfunctions, if K t If the time does not drop to C2 but reaches the third duration L2 or higher, then a forced switch to the next stage will be initiated.

[0161] In step S1050, the defrosting process ends.

[0162] At this point, the defrosting heater stops working, the frost layer becomes thinner and thinner, and the number of water droplets in the drain pipe decreases. t The temperature approaches zero. However, at this point, the temperature of the heat-insulating mechanism and the cooling chamber will slowly rise, and the controller will control the heat-insulating mechanism to reduce its speed exponentially.

[0163] The rotational speed R during the t-th time period t For: R t = R t2 ×e^(-p×t b-c ); where R t2 For K t The rotational speed of the heat-resistant mechanism when it drops to the third threshold C2, p is the attenuation coefficient (a positive constant), t b-c This refers to the t-th time period in the defrosting process (take an integer, such as 0, 1, 2, etc.).

[0164] In step S1060, the heat-insulating mechanism is shut down.

[0165] When K t When Kt drops below the fourth threshold C3, the controller shuts down the heat-resistant mechanism. If Kt does not drop to C3 during this stage but Time reaches the fourth duration L3 or more, the heat-resistant mechanism is forcibly shut down.

[0166] In step S1070, defrosting is complete.

[0167] The controller confirms that the defrosting process is complete, exits defrosting mode, and waits for the next defrosting command.

[0168] In summary, this application, by installing a vibration sensor in the defrost water discharge path below the evaporator, directly detects the vibration signal generated by the falling defrost water droplets. The defrost water generation rate is quantified using the pulse change rate, thus reflecting the overall frost melting speed of the evaporator. Based on this, the heat-resistant mechanism is controlled by frequency conversion. Compared to existing technologies that use temperature sensors to monitor only local air temperature and cannot accurately determine the overall defrosting degree of the evaporator, this application overcomes the localization and lag problems of temperature detection by detecting defrost water, a direct product of the defrosting process. It is unaffected by airflow interference, has a fast response speed, and can more comprehensively and accurately determine the real-time defrosting progress of the entire evaporator. This achieves real-time and precise matching between the rotation speed of the heat-resistant mechanism and the amount of defrosting heat generated, avoiding energy waste caused by premature start-up or heat intrusion caused by late shutdown, effectively reducing room temperature rise and energy consumption in the cooling room.

[0169] Furthermore, based on the changing trend of the pulse change rate and the set threshold, the defrosting process is divided into different stages and a differentiated speed adjustment strategy is adopted for each stage: in the initial stage of defrosting, the frequency is uniformly increased with a constant change rate to adapt to the low heat generation state of the frost layer melting slowly and uniformly; in the peak stage of defrosting, the frequency is non-uniformly increased with a pulse change rate to quickly respond to the large amount of heat accumulation caused by the rapid melting of the core of the frost layer; in the final stage of defrosting, the speed is reduced exponentially with an attenuation coefficient to achieve a smooth transition from effective blocking to complete stop.

[0170] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of this application is limited only by the appended claims.

Claims

1. A refrigerator characterized by comprising: include: The enclosure defines a refrigeration chamber. An evaporator, located outside the refrigeration chamber, is used to supply cold air to the refrigeration chamber; A defrosting heater is provided on one side of the evaporator to provide defrosting heat to melt the frost layer on its surface. A heat-insulating mechanism, located outside the refrigeration chamber, is used to generate an airflow barrier by rotating to prevent the defrosting heat generated by the defrosting heater from entering the refrigeration chamber; A vibration sensor is installed in the defrost water discharge path of the evaporator to detect the vibration signal generated by the falling defrost water droplets. The vibration signal is a discrete pulse signal generated by the falling defrost water droplets impacting the vibration sensor. The controller, electrically connected to the vibration sensor and the heat-resistant mechanism, is configured to perform: When the defrosting heater is started, the vibration signal detected by the vibration sensor is acquired, and the pulse change rate is determined based on the vibration signal. The pulse change rate is used to reflect the melting speed of the frost layer on the evaporator surface. The start-up, shutdown, and rotation speed of the heat-resistant mechanism are controlled according to the pulse change rate, so that the rotation speed of the heat-resistant mechanism matches the melting speed of the frost layer on the evaporator surface.

2. The refrigerator according to claim 1, characterized in that, Controlling the start / stop and rotation speed of the heat-resistant mechanism based on the pulse change rate, so that the rotation speed of the heat-resistant mechanism matches the melting speed of the frost layer on the evaporator surface, includes: Based on the trend of the pulse change rate and the set threshold, the heat-resistant mechanism is frequency-controlled so that the rotation speed of the heat-resistant mechanism increases as the melting speed of the frost layer on the evaporator surface increases and decreases as the melting speed of the frost layer on the evaporator surface decreases.

3. The refrigerator according to claim 2, characterized in that, Based on the changing trend of the pulse rate of change and a set threshold, frequency conversion control is performed on the heat-resistant mechanism, including: When the pulse change rate rises above the first threshold, the heat-blocking mechanism is activated, and the rotation speed of the heat-blocking mechanism is controlled to increase at a constant change rate. When the pulse change rate rises above the second threshold, the rotation speed of the heat-insulating mechanism is controlled to increase non-uniformly based on the pulse change rate, wherein the second threshold is greater than the first threshold. When the pulse change rate drops below the third threshold, the rotation speed of the heat-insulating mechanism is controlled to decrease exponentially based on the attenuation coefficient, and the third threshold is less than the second threshold. When the pulse change rate drops below the fourth threshold, the heat-blocking mechanism is shut down, where the fourth threshold is less than the third threshold.

4. The refrigerator according to claim 3, characterized in that, Controlling the rotational speed of the heat-resistant mechanism based on the non-uniform increase of the pulse change rate includes: using the rotational speed of the heat-resistant mechanism when the pulse change rate rises to the second threshold as a first reference rotational speed, controlling the rotational speed of the heat-resistant mechanism to be superimposed with a first adjustment amount on the first reference rotational speed, wherein the first adjustment amount increases non-uniformly with the increase of the pulse change rate; or Controlling the rotation speed of the heat-resistant mechanism to decrease exponentially based on the attenuation coefficient includes: taking the rotation speed of the heat-resistant mechanism when the pulse change rate decreases to the third threshold as the second reference rotation speed, and controlling the rotation speed of the heat-resistant mechanism to decrease exponentially over time from the second reference rotation speed.

5. The refrigerator according to claim 3, characterized in that, Also includes: If the defrosting heater's start-up duration exceeds a first duration before the pulse change rate rises to the first threshold, the heat-blocking mechanism is activated, and the rotation speed of the heat-blocking mechanism is controlled to increase at a constant rate of change. If the start-up duration of the defrosting heater reaches a second duration or more before the pulse change rate rises to the second threshold, the rotation speed of the heat-resistant mechanism is controlled to increase non-uniformly based on the pulse change rate, where the second duration is greater than the first duration. If the start-up duration of the defrosting heater reaches more than the third duration before the pulse change rate drops to the third threshold, the rotation speed of the heat-resistant mechanism is controlled to decrease exponentially based on the attenuation coefficient, and the third duration is greater than the second duration. If the duration of the defrosting heater's operation reaches or exceeds the fourth duration before the pulse change rate drops to the fourth threshold, the heat-blocking mechanism is shut down, where the fourth duration is longer than the third duration.

6. The refrigerator according to claim 2, characterized in that, The heat-resistant mechanism is a fan; the start-up, shutdown, and rotation speed of the heat-resistant mechanism are controlled according to the pulse change rate, so that the rotation speed of the heat-resistant mechanism matches the melting rate of the frost layer on the evaporator surface, including: The upper limit of the rotational speed of the heat-insulating mechanism is controlled to be below 80% of its rated rotational speed.

7. The refrigerator according to any one of claims 1 to 6, characterized in that, It also includes a drainage system, which comprises: The defrosting water inlet is located at the bottom of the evaporator; The drain pipe is connected to the defrost water inlet. A drainage collection structure is connected to the defrost water receiving part through the drain pipe, and the drainage collection structure is located above or inside the evaporating dish; The bottom of the drainage collection structure has an opening, and the vibration sensor is installed at a downward angle at the opening and fixed to the bottom of the drainage collection structure.

8. The refrigerator according to claim 7, characterized in that, The drainage collection structure is funnel-shaped, wider at the top and narrower at the bottom. Its sidewalls extend upward from the edge of the opening to form an inner cavity for receiving defrost water. The bottom surface of the drainage collection structure is inclined relative to the horizontal plane. The vibration sensor is sealed at the opening and is sealed to the bottom surface of the drainage collection structure. The sidewalls of the drainage collection structure have drainage outlets for guiding the defrost water flowing over the surface of the vibration sensor to the evaporation dish.

9. The refrigerator according to claim 8, characterized in that The vibration sensor is a piezoelectric vibration sensor, comprising a piezoelectric wafer, an electrode layer, a base, and leads. The piezoelectric wafer is used to deform under the impact of defrosting water droplets. The electrode layer is disposed on the surface of the piezoelectric wafer and is used to draw out piezoelectric charges. The base is used to support and fix the piezoelectric wafer; the lead wire is connected to the electrode layer and is used to output the vibration signal; the outside of the evaporation dish is provided with an inclined groove, the groove extends upward, and the lead wire passes through the evaporation dish and passes through the groove.

10. A control method of a heat-blocking mechanism for a refrigerator, characterized by, The heat-blocking mechanism generates an airflow barrier by rotating to prevent defrosting heat from entering the refrigeration compartment. The refrigerator includes a vibration sensor located in the defrosting water drainage path of the evaporator to detect vibration signals generated by falling defrosting water droplets. The vibration signal is a discrete pulse signal generated by the falling defrosting water droplets impacting the vibration sensor. The control method includes: When the defrosting heater is started, the vibration signal detected by the vibration sensor is acquired, and the pulse change rate is determined based on the vibration signal. The pulse change rate is used to reflect the melting speed of the frost layer on the evaporator surface. The start-up, shutdown, and rotation speed of the heat-resistant mechanism are controlled according to the pulse change rate, so that the rotation speed of the heat-resistant mechanism matches the melting speed of the frost layer on the evaporator surface.

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