Refrigerator system and method based on condensation heat recovery and asynchronous collaborative defrosting

Abstract

The invention provides a refrigerator system and method based on condensation heat recovery and asynchronous cooperative defrosting, and the method comprises the steps: when the frosting thickness detected by a frost layer thickness sensor is greater than or equal to 3mm, or the accumulated compressor operation time recorded by a main control board is greater than or equal to a preset operation threshold value, and a compressor is in an operation state, a defrosting instruction is sent; after a defrosting instruction is received, the three-way electromagnetic valve is controlled to be switched to the second outlet to be conducted and the first outlet to be closed, and the compressor is kept running continuously; when the instant temperature of the evaporator is 0 DEG C, the compressor stops running; the main control board starts the steel pipe heater and adjusts the power of the steel pipe heater according to the evaporator instant temperature detected by the temperature sensor; and when the evaporator instant temperature detected by the temperature sensor reaches the temperature threshold value, the steel pipe heater is closed, and the defrosting instruction is ended. Heat in the condenser is continuously conveyed to the evaporator for defrosting by means of continuous operation of the compressor and change of an outlet of the electromagnetic valve, and energy consumption of the refrigerator is reduced.

Description

Technical Field

[0001] This application relates to the field of refrigerator technology, and in particular to a refrigerator system and method based on condensation heat recovery and asynchronous collaborative defrosting. Background Technology

[0002] In the field of refrigerator refrigeration technology, frost-free refrigerators are widely used in household and similar applications due to their efficient forced air circulation for heat exchange. Their core refrigeration component is the finned evaporator. During normal operation, the refrigerant temperature inside the evaporator remains below 0°C. During this process, moisture in the air inside the refrigerator compartment gradually condenses on the evaporator fins, accumulating over time to form a frost layer. This frost layer significantly increases airflow resistance and reduces the evaporator's heat exchange efficiency, thus affecting the overall refrigeration performance of the refrigerator. Therefore, frost-free refrigerators require periodic defrosting to remove the frost from the evaporator surface and ensure stable operation of the refrigeration system. This is an indispensable and crucial aspect of daily use for frost-free refrigerators.

[0003] Currently, the mainstream defrosting method for existing air-cooled refrigerators is electric heating defrosting. Specifically, a steel pipe heater is usually suspended below the finned evaporator. When the refrigerator meets the preset defrosting trigger conditions (such as the cumulative running time reaching a set value, the frost thickness reaching a threshold, etc.), the refrigerator's main control system activates the steel pipe heater. The heat generated by the heater directly heats and melts the frost condensed on the evaporator surface, thus achieving the purpose of removing the frost. This defrosting method can complete the defrosting operation with a single electric heating component, has a relatively simple structure, and has become a mature application in the refrigerator industry.

[0004] However, the existing defrosting methods described above have significant drawbacks in practical applications, specifically in the following two aspects: First, high energy consumption. The electric defrosting process requires continuous electrical energy consumption. According to industry standards, the energy increase from the defrosting stage accounts for 10%-20% of the total power consumption of the refrigerator, significantly increasing the operating costs and energy consumption. Second, large temperature fluctuations in the compartments. With a single electric heating method, the heat generated by the heater easily leaks into the refrigerator compartments during defrosting, causing significant temperature fluctuations, especially in the temperature-sensitive freezer compartment, where temperature fluctuations during defrosting often exceed 6°C. Such temperature fluctuations disrupt the stable low-temperature environment of the freezer compartment, shorten the shelf life of food, and may even lead to a decline in food quality, posing a risk to food preservation. Summary of the Invention

[0005] This application provides a refrigerator system and method based on condensation heat recovery and asynchronous collaborative defrosting to solve the problem that the defrosting technology of refrigerators in the prior art causes abnormal temperature fluctuations and even unstable defrosting effect, which affects the energy efficiency and heat preservation performance of the refrigerator.

[0006] In a first aspect, this application provides a refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting, including a refrigeration system and a defrosting system;

[0007] The refrigeration system consists of a compressor, condenser, filter, three-way solenoid valve, anti-condensation tube, capillary tube, evaporator, and a defrosting bypass pipeline. The outlet of the condenser is connected to the inlet of the filter, the outlet of the filter is connected to the inlet of the three-way solenoid valve, the first outlet of the three-way solenoid valve is connected to the inlet of the capillary tube, the outlet of the capillary tube is connected to the inlet of the evaporator, the second outlet of the three-way solenoid valve is connected to the inlet of the defrosting bypass pipeline, the outlet of the defrosting bypass pipeline is connected to the inlet of the evaporator, and the anti-condensation tube is integrated into the refrigerant flow path of the refrigeration system.

[0008] The defrosting system includes a main control board, a temperature sensor, a frost thickness sensor, and a steel pipe heater. The main control board is equipped with a control module for controlling the operation of the compressor, a three-way solenoid valve, and the steel pipe heater. The temperature sensor is installed at the inlet or outlet of the evaporator to detect the instantaneous temperature of the evaporator. The frost thickness sensor is installed on the surface of the evaporator to detect the frost thickness. The steel pipe heater is located at the bottom of the evaporator to assist in defrosting.

[0009] In some possible implementations, the three-way solenoid valve is an electric rotary valve or a bistable solenoid valve, and the three-way solenoid valve includes an inlet, a first outlet and a second outlet, and the solenoid valve is used to select the outlet through which the refrigerant flows as needed.

[0010] In some possible implementations, the refrigerant flow path of the refrigeration system has two conduction states:

[0011] The first conduction state is from the compressor, condenser, filter, three-way solenoid valve, capillary tube to evaporator;

[0012] The second conduction state is from the compressor, condenser, filter, three-way solenoid valve, and defrost-specific bypass line to the evaporator.

[0013] In some possible implementations, the control module is configured as follows:

[0014] When the frost thickness detected by the frost thickness sensor is ≥3mm, or the cumulative compressor running time recorded by the main control board is ≥ the preset running threshold, and the compressor is in operation, a defrosting command is sent.

[0015] Upon receiving a defrost command, the three-way solenoid valve is switched to open the second outlet and close the first outlet, allowing refrigerant to flow into the evaporator through the dedicated defrost bypass line, and keeping the compressor running continuously.

[0016] The compressor stops operating when the instantaneous temperature of the evaporator reaches 0°C.

[0017] The main control board starts the steel pipe heater and adjusts the power of the steel pipe heater according to the real-time temperature of the evaporator detected by the temperature sensor.

[0018] When the evaporator temperature detected by the temperature sensor reaches the temperature threshold, the steel pipe heater is turned off, the defrosting command ends, and the refrigerator returns to normal cooling mode.

[0019] In some possible implementations, after the refrigerant flows into the evaporator via a dedicated defrosting bypass line, the control module is further configured to:

[0020] The base runtime and corrected runtime of the compressor are calculated based on the frost layer thickness.

[0021] When the compressor's operating time equals the corrected operating time, the compressor stops operating; if the evaporator's instantaneous temperature reaches 0°C first, the compressor stops operating immediately regardless of whether the corrected operating time has been reached.

[0022] In some possible implementations, the control module is further configured as follows:

[0023] After the defrosting command ends, the refrigerator enters the dripping time. After the dripping time ends, the main control board controls the three-way solenoid valve to switch to the first outlet open and the second outlet closed, starts the compressor and evaporator fan, and the refrigerator returns to normal cooling mode.

[0024] In some possible implementations, the control module is further configured as follows:

[0025] The compressor's exhaust temperature is collected in real time. If the exhaust temperature is ≥90℃, the three-way solenoid valve is controlled to switch to the first outlet. After the exhaust temperature drops to 80℃, it is switched back to the second outlet.

[0026] In some possible implementations, the control module is further configured as follows:

[0027] Obtain the external ambient temperature of the refrigerator as detected by the ambient temperature sensor;

[0028] When the external ambient temperature of the refrigerator is ≥30℃, the cumulative compressor running time threshold will be lowered by 10%-15%; when the external ambient temperature of the refrigerator is ≤5℃, the cumulative compressor running time threshold will be raised by 10%-15%.

[0029] In some possible implementations, the control module is further configured as follows:

[0030] If the temperature sensor detects that the evaporator temperature does not rise or rises by ≤1℃ within 5 minutes after starting the steel pipe heater on the main control board, it is determined to be a defrosting abnormality. The power of the steel pipe heater is adjusted to the rated power, and a fault prompt signal is sent to the refrigerator display panel.

[0031] Secondly, this application provides a defrosting control method based on condensation heat recovery and asynchronous collaborative defrosting, the method being applied to the refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting described in the first aspect;

[0032] The method includes:

[0033] When the frost thickness detected by the frost thickness sensor is ≥3mm, or the cumulative compressor running time recorded by the main control board is ≥ the preset running threshold, and the compressor is in operation, a defrosting command is sent.

[0034] Upon receiving a defrost command, the three-way solenoid valve is switched to open the second outlet and close the first outlet, allowing refrigerant to flow into the evaporator through the dedicated defrost bypass line, and keeping the compressor running continuously.

[0035] The compressor stops operating when the instantaneous temperature of the evaporator reaches 0°C.

[0036] The main control board starts the steel pipe heater and adjusts the power of the steel pipe heater according to the real-time temperature of the evaporator detected by the temperature sensor.

[0037] When the evaporator temperature detected by the temperature sensor reaches the temperature threshold, the steel pipe heater is turned off, the defrosting command ends, and the refrigerator returns to normal cooling mode.

[0038] As can be seen from the above, this application provides a refrigerator system and method based on condensation heat recovery and asynchronous collaborative defrosting. The method includes sending a defrosting command when the frost thickness detected by the frost thickness sensor is ≥3mm, or the cumulative compressor running time recorded by the main control board is ≥ a preset operating threshold, and the compressor is in operation; after receiving the defrosting command, controlling the three-way solenoid valve to switch to the second outlet open and the first outlet closed, so that the refrigerant flows into the evaporator through the defrosting bypass pipeline, and keeping the compressor running continuously; when the instantaneous temperature of the evaporator is 0℃, stopping the compressor operation; the main control board starts the steel pipe heater and adjusts the power of the steel pipe heater according to the instantaneous temperature of the evaporator detected by the temperature sensor; when the instantaneous temperature of the evaporator detected by the temperature sensor reaches the temperature threshold, turning off the steel pipe heater, ending the defrosting command, and the refrigerator returns to normal cooling mode. This application adds a one-in-two-out solenoid valve to the refrigerator's refrigeration system. During defrosting, the continuous operation of the compressor and the change in the solenoid valve outlet allow heat from the condenser to be continuously transferred to the evaporator for defrosting, reducing the heating energy of the electric heater and achieving the goal of reducing refrigerator energy consumption while ensuring defrosting reliability. Attached Figure Description

[0039] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 A refrigerator system diagram based on condensation heat recovery and asynchronous collaborative defrosting provided for this application;

[0041] Figure 2 This application provides a scenario diagram of a refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting. Detailed Implementation

[0042] The embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described below do not represent all embodiments consistent with this application. They are merely examples of systems and methods consistent with some aspects of this application as detailed in the claims.

[0043] In the field of refrigerator refrigeration technology, frost-free refrigerators are widely used in household and similar applications due to their efficient forced air circulation for heat exchange. Their core refrigeration component is the finned evaporator. During normal operation, the refrigerant temperature inside the evaporator remains below 0°C. During this process, moisture in the air inside the refrigerator compartment gradually condenses on the evaporator fins, accumulating over time to form a frost layer. This frost layer significantly increases airflow resistance and reduces the evaporator's heat exchange efficiency, thus affecting the overall refrigeration performance of the refrigerator. Therefore, frost-free refrigerators require periodic defrosting to remove the frost from the evaporator surface and ensure stable operation of the refrigeration system. This is an indispensable and crucial aspect of daily use for frost-free refrigerators.

[0044] Currently, the mainstream defrosting method for existing air-cooled refrigerators is electric heating defrosting. Specifically, a steel pipe heater is usually suspended below the finned evaporator. When the refrigerator meets the preset defrosting trigger conditions (such as the cumulative running time reaching a set value, the frost thickness reaching a threshold, etc.), the refrigerator's main control system activates the steel pipe heater. The heat generated by the heater directly heats and melts the frost condensed on the evaporator surface, thus achieving the purpose of removing the frost. This defrosting method can complete the defrosting operation with a single electric heating component, has a relatively simple structure, and has become a mature application in the refrigerator industry.

[0045] However, the existing defrosting methods described above have significant drawbacks in practical applications, specifically in the following two aspects: First, high energy consumption. The electric defrosting process requires continuous electrical energy consumption. According to industry standards, the energy increase from the defrosting stage accounts for 10%-20% of the total power consumption of the refrigerator, significantly increasing the operating costs and energy consumption. Second, large temperature fluctuations in the compartments. With a single electric heating method, the heat generated by the heater easily leaks into the refrigerator compartments during defrosting, causing significant temperature fluctuations, especially in the temperature-sensitive freezer compartment, where temperature fluctuations during defrosting often exceed 6°C. Such temperature fluctuations disrupt the stable low-temperature environment of the freezer compartment, shorten the shelf life of food, and may even lead to a decline in food quality, posing a risk to food preservation.

[0046] Based on this, such as Figure 1 As shown, this application provides a refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting, including a refrigeration system and a defrosting system;

[0047] The refrigeration system consists of a compressor, condenser, filter, three-way solenoid valve, anti-condensation tube, capillary tube, evaporator, and a defrosting bypass pipeline. The outlet of the condenser is connected to the inlet of the filter, the outlet of the filter is connected to the inlet of the three-way solenoid valve, the first outlet of the three-way solenoid valve is connected to the inlet of the capillary tube, the outlet of the capillary tube is connected to the inlet of the evaporator, the second outlet of the three-way solenoid valve is connected to the inlet of the defrosting bypass pipeline, the outlet of the defrosting bypass pipeline is connected to the inlet of the evaporator, and the anti-condensation tube is integrated into the refrigerant flow path of the refrigeration system.

[0048] The defrosting system includes a main control board, a temperature sensor, a frost thickness sensor, and a steel pipe heater. The main control board is equipped with a control module for controlling the operation of the compressor, a three-way solenoid valve, and the steel pipe heater. The temperature sensor is installed at the inlet or outlet of the evaporator to detect the instantaneous temperature of the evaporator. The frost thickness sensor is installed on the surface of the evaporator to detect the frost thickness. The steel pipe heater is located at the bottom of the evaporator to assist in defrosting.

[0049] By adding a three-way solenoid valve and a dedicated defrosting bypass pipeline to the refrigeration system, the refrigerant flow direction can be switched during defrosting, allowing the high-temperature gaseous refrigerant in the condenser to directly enter the evaporator for hot gas defrosting. This prioritizes the use of waste heat from condensation to melt the frost layer on the main body of the evaporator, reducing reliance on the steel pipe heater. Combined with dynamic power adjustment during the electric heating synergy stage (adapting the output power according to the formula to avoid continuous operation at rated power), compared to traditional single electric heating defrosting, defrosting energy consumption can be reduced by more than 25%, and the defrosting increment (W·h) is reduced from the traditional 100-160 to 60-120, lowering the proportion of total refrigerator energy consumption.

[0050] Optimizing defrosting efficiency and reliability: During the hot gas defrosting stage, a dynamic time calculation model (Tactual = Tbase × (1 + (-18 - tevp) / 18)) based on a "base time combined with evaporator temperature correction" can precisely control the defrosting time according to the frost thickness and the real-time evaporator temperature, ensuring rapid melting of the main frost layer. In the subsequent electric heating stage, the evaporator temperature is precisely tracked to the threshold (5℃ or 8℃), thoroughly removing residual frost and preventing a decrease in cooling efficiency due to incomplete defrosting. Simultaneously, the total defrosting time is reduced from the traditional 20-30 minutes to 15-25 minutes, improving defrosting efficiency.

[0051] In some embodiments, the three-way solenoid valve is an electric rotary valve or a bistable solenoid valve. The three-way solenoid valve includes an inlet, a first outlet, and a second outlet. The solenoid valve is used to select the outlet through which the refrigerant flows as needed.

[0052] The "one inlet, two outlets" structure of the three-way solenoid valve (electric rotary valve or bistable solenoid valve) can accurately respond to the refrigerant flow requirements of different refrigerator operating modes. During normal cooling, it connects the first outlet to the capillary tube to ensure that the refrigerant completes the refrigeration cycle according to the conventional flow path of "compressor → condenser → capillary tube → evaporator". During defrosting, it switches to the second outlet and connects to the defrosting bypass pipeline, allowing the high-temperature gaseous refrigerant in the condenser to directly enter the evaporator to achieve hot gas defrosting. It provides key flow path control support for the core function of "condensation heat recovery defrosting combined with electric heating for coordinated defrosting" and is the core component for the smooth switching between the two operating modes.

[0053] When choosing an electric rotary valve, its valve opening adjustment is flexible and its flow path switching response is fast, which can quickly adapt to the immediate need for refrigerant flow direction switching during defrosting startup and reduce defrosting efficiency loss caused by flow path switching delay. When choosing a bistable solenoid valve, it has low power consumption characteristics (power is only required when switching, and no power is required to maintain the state), which can further reduce the overall energy consumption of the refrigerator. It also has high structural reliability and long service life, which can reduce the impact of valve failure on system operation. The two valve types are suitable for different design requirements, improving the overall design flexibility of the system.

[0054] In some embodiments, the refrigerant flow path of the refrigeration system has two conduction states:

[0055] The first conduction state is compressor → condenser → filter → three-way solenoid valve → capillary tube → evaporator;

[0056] The second conduction state is compressor → condenser → filter → three-way solenoid valve → defrost bypass line → evaporator.

[0057] The two refrigerant flow path states correspond to the refrigerator's normal cooling mode and defrost mode, respectively, providing a key flow path foundation for "condensation heat recovery defrosting". Under normal conditions, the first flow path state (throttling through the capillary tube) ensures that the refrigerant completes heat absorption and release according to the standard refrigeration cycle, achieving compartment cooling. During defrosting, switching to the second flow path state (through a dedicated defrost bypass line) bypasses the throttling effect of the capillary tube, allowing the high-temperature gaseous refrigerant output from the condenser to directly enter the evaporator. The condensation heat is used for hot gas defrosting, eliminating the need for an additional independent defrost heat source circuit and achieving a smooth switch between "cooling" and "defrosting" functions.

[0058] In the second conduction state, the flow path design where high-temperature refrigerant directly enters the evaporator can directly recover the "waste heat" (heat of high-temperature gaseous refrigerant) generated by the condenser during the refrigeration process, which would otherwise be dissipated through heat dissipation components in traditional systems, and prioritize its use for defrosting the frost layer. Compared to traditional single-electric defrosting that relies entirely on electrical energy for heat generation, this flow path can replace part of the electric heating load. Combined with dynamic power adjustment in the subsequent electric heating coordination stage, it can reduce defrosting energy consumption by more than 25%, and the defrosting increment (W·h) is reduced from the traditional 100-160 to 60-120, effectively reducing the proportion of total energy consumption of the refrigerator.

[0059] In some embodiments, the control module is configured to:

[0060] When the frost thickness detected by the frost thickness sensor is ≥3mm, or the cumulative compressor running time recorded by the main control board is ≥ the preset running threshold, and the compressor is in operation, a defrosting command is sent.

[0061] Upon receiving a defrost command, the three-way solenoid valve is switched to open the second outlet and close the first outlet, allowing refrigerant to flow into the evaporator through the dedicated defrost bypass line, and keeping the compressor running continuously.

[0062] The compressor stops operating when the instantaneous temperature of the evaporator reaches 0°C.

[0063] The main control board starts the steel pipe heater and adjusts the power of the steel pipe heater according to the real-time temperature of the evaporator detected by the temperature sensor.

[0064] When the evaporator temperature detected by the temperature sensor reaches the temperature threshold, the steel pipe heater is turned off, the defrosting command ends, and the refrigerator returns to normal cooling mode.

[0065] In some embodiments, the defrosting process of this application is divided into the following parts: hot gas defrosting monitoring stage, hot gas defrosting execution stage, and electric heating coordination stage.

[0066] The hot gas defrosting monitoring phase is as follows: when the frost thickness detected by the frost thickness sensor is ≥3mm, or the cumulative compressor running time recorded by the main control board is ≥ the preset running threshold, and the compressor is in operation, a defrosting command is sent.

[0067] The hot gas defrosting execution phase is as follows: after receiving the defrosting command, the three-way solenoid valve is controlled to switch to the second outlet being open and the first outlet being closed, so that the refrigerant flows into the evaporator through the defrosting bypass pipeline, and the compressor is kept running continuously;

[0068] When the instantaneous temperature of the evaporator reaches 0°C, the compressor stops operating.

[0069] After the hot defrosting process is complete, the electric heater should be started at this time.

[0070] The main control board starts the steel pipe heater and adjusts the power of the steel pipe heater according to the real-time temperature of the evaporator detected by the temperature sensor.

[0071] When the instantaneous temperature of the evaporator detected by the temperature sensor reaches the temperature threshold t max Turn off the steel pipe heater; the temperature threshold is usually set at 5 or 8°C.

[0072] The power of the electric heater is adjusted according to the temperature of the evaporator sensor. After the electric defrosting begins, the power is adjusted every minute until the electric defrosting process is completed.

[0073] P heater =P 额定 ×(t max -t evp +k) / t max ;

[0074] Where: k is the adjustment coefficient, which can usually be 1 or 2;

[0075] If P heater Calculation result ≥ P 额定 Then P heater =P 额定 .

[0076] In some embodiments, after the refrigerant flows into the evaporator through a dedicated defrosting bypass line, the control module is further configured to:

[0077] The base runtime and corrected runtime of the compressor are calculated based on the frost layer thickness.

[0078] When the compressor's operating time equals the corrected operating time, the compressor stops operating; if the evaporator's instantaneous temperature reaches 0°C first, the compressor stops operating immediately regardless of whether the corrected operating time has been reached.

[0079] Base duration T base =Df ×2min / mm, and corrected according to the real-time temperature of the evaporator:

[0080] D f Frost layer thickness, mm; Hot air defrosting correction runtime:

[0081] T actual =T base ×(1+(-18-t evp ) / 18);

[0082] t evp : Evaporator instantaneous temperature, °C;

[0083] Hot defrosting complete sign:

[0084] T actual Reach or T evp =0℃, take the first one reached; at this time the compressor stops and enters the electric heating defrosting stage.

[0085] By employing a dual-parameter calculation logic that combines a base duration with a corrected runtime, the compressor runtime can be dynamically determined based on the actual frost thickness (Df) and instantaneous temperature (tevp) of the evaporator. The thicker the frost, the longer the base duration, ensuring sufficient heat for melting the main frost layer; conversely, the lower the evaporator temperature, the longer the corrected runtime, compensating for the extra heat required for frost melting in low-temperature environments. Compared to traditional fixed-duration hot gas defrosting control, this avoids energy waste caused by excessive operation when frost is thin or incomplete defrosting due to insufficient operation when frost is thick, achieving a precise match between defrosting energy and actual demand.

[0086] By setting a trigger mechanism that "stops the compressor immediately when the evaporator temperature reaches 0°C," the system can directly switch to the subsequent electric heating stage when the frost layer has melted ahead of schedule, without waiting for the correction running time to end. This design can fully utilize the defrosting effect of condensation heat and avoid ineffective compressor operation. For example, when the frost layer is thin or the initial evaporator temperature is high (close to 0°C), hot gas defrosting can be completed quickly, reducing the compressor's extra running time in the defrosting stage, thereby shortening the overall defrosting cycle and improving the refrigerator's cooling and defrosting cycle efficiency.

[0087] In some embodiments, the control module is further configured to:

[0088] After the defrosting command ends, the refrigerator enters the dripping time. After the dripping time ends, the main control board controls the three-way solenoid valve to switch to the first outlet open and the second outlet closed, starts the compressor and evaporator fan, and the refrigerator returns to normal cooling mode.

[0089] After the defrost command ends, the dripping time begins, allowing residual defrost water on the evaporator surface (especially water accumulated in the fin gaps and pipe connections) to drip fully into the drip tray. This prevents a sudden drop in evaporator temperature caused by directly starting the cooling mode, which could lead to refreezing of the residual water and the formation of a new frost layer. This process thoroughly removes residual defrost water, prevents "rapid re-frost" issues, ensures the evaporator's heat exchange efficiency during subsequent cooling processes, and avoids additional energy consumption due to secondary frosting.

[0090] After the dripping time ends, the main control board first controls the three-way solenoid valve to switch to the first outlet (conventional refrigeration flow path) and closes the second outlet (defrost bypass line). Then, it starts the compressor and evaporator fan. This sequence ensures that the refrigerant flow path first returns to the conventional refrigeration state before refrigerant is introduced and airflow circulation begins. Compared to "starting the compressor first and then switching the valve path," this avoids localized high pressure or unstable flow of refrigerant when the flow path is not fully open, reduces the load impact during compressor startup, lowers system pipeline pressure fluctuations, extends the service life of core components such as the compressor and solenoid valve, and improves system operational stability.

[0091] In some embodiments, the control module is further configured to:

[0092] The compressor's exhaust temperature is collected in real time. If the exhaust temperature is ≥90℃, the three-way solenoid valve is controlled to switch to the first outlet. After the exhaust temperature drops to 80℃, it is switched back to the second outlet.

[0093] During the hot gas defrosting stage (when refrigerant enters the evaporator via a bypass line), the compressor continuously runs and outputs high-temperature gaseous refrigerant. If the exhaust temperature continues to rise to ≥90℃, it can easily trigger the compressor's own high-temperature protection mechanism (shutdown protection), causing the hot gas defrosting to be interrupted, resulting in incomplete defrosting and prolonged defrosting time. By real-time acquisition of the exhaust temperature and triggering the solenoid valve to switch, the first outlet (conventional refrigeration flow path) is opened when the temperature is high, allowing the refrigerant to enter the evaporator after being throttled through the capillary tube, which can quickly reduce the compressor's exhaust pressure and temperature. Once the temperature drops below 80℃ (outside the high-temperature risk range), it switches back to the second outlet, which can avoid compressor shutdown, ensure the continuous hot gas defrosting process, guarantee defrosting efficiency and reliability, and meet the invention objective of "considering defrosting reliability" in the technical disclosure.

[0094] When the compressor discharge temperature is too high (≥90℃), it will cause the viscosity of the lubricating oil inside the compressor to decrease, weakening the lubrication effect and accelerating the wear of moving parts such as pistons and cylinders. At the same time, high temperature may also accelerate the aging of the motor insulation layer, shortening the compressor's service life. The above control steps, by timely switching the flow path to cool down, can control the compressor discharge temperature within a safe range (≤80℃), avoiding lubricating oil failure and overheating damage to components, reducing the risk of compressor failure, extending its service life, and ensuring the long-term stable operation of the refrigerator system.

[0095] In some embodiments, the control module is further configured to:

[0096] Obtain the external ambient temperature of the refrigerator as detected by the ambient temperature sensor;

[0097] When the external ambient temperature of the refrigerator is ≥30℃, the cumulative compressor running time threshold will be lowered by 10%-15%; when the external ambient temperature of the refrigerator is ≤5℃, the cumulative compressor running time threshold will be raised by 10%-15%.

[0098] The external ambient temperature directly affects the frost formation rate of the evaporator. When the ambient temperature is ≥30℃, the water vapor content in the air is higher, and the temperature difference between the compartment and the evaporator easily causes water vapor to condense on the evaporator more quickly, accelerating the frost formation rate. In this case, lowering the cumulative compressor running time threshold (10%-15%) can trigger the defrosting action earlier, avoiding a decrease in cooling efficiency due to excessively thick frost (more than 3mm). When the ambient temperature is ≤5℃, the air humidity is low and the water vapor content is low, slowing down the evaporator frost formation rate. In this case, raising the threshold (10%-15%) can avoid frequent defrosting when the frost amount is insufficient, reducing unnecessary defrosting energy consumption and compartment temperature fluctuations, achieving a precise match between the defrosting trigger timing and the actual frost formation situation.

[0099] In some embodiments, the control module is further configured to:

[0100] If the temperature sensor detects that the evaporator temperature does not rise or rises by ≤1℃ within 5 minutes after starting the steel pipe heater on the main control board, it is determined to be a defrosting abnormality. The power of the steel pipe heater is adjusted to the rated power, and a fault prompt signal is sent to the refrigerator display panel.

[0101] In some embodiments, this application provides a method for controlling condensation heat recovery and asynchronous collaborative defrosting, which is applied to the refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting described in the above embodiments;

[0102] The method includes:

[0103] When the frost thickness detected by the frost thickness sensor is ≥3mm, or the cumulative compressor running time recorded by the main control board is ≥ the preset running threshold, and the compressor is in operation, a defrosting command is sent.

[0104] Upon receiving a defrost command, the three-way solenoid valve is switched to open the second outlet and close the first outlet, allowing refrigerant to flow into the evaporator through the dedicated defrost bypass line, and keeping the compressor running continuously.

[0105] The compressor stops operating when the instantaneous temperature of the evaporator reaches 0°C.

[0106] The main control board starts the steel pipe heater and adjusts the power of the steel pipe heater according to the real-time temperature of the evaporator detected by the temperature sensor.

[0107] When the evaporator temperature detected by the temperature sensor reaches the temperature threshold, the steel pipe heater is turned off, the defrosting command ends, and the refrigerator returns to normal cooling mode.

[0108] Example

[0109] like Figure 1 The present application provides a refrigerator system diagram based on condensation heat recovery and asynchronous collaborative defrosting. The system includes a refrigeration system and a defrosting system, consisting of a compressor 11, an anti-condensation pipe 21, a condenser 31, a filter 41, a solenoid valve 51, a capillary tube 61, an evaporator 71, and a bypass pipe 81. The inlet of the solenoid valve 51 is connected to the outlet of the condenser 31. The first outlet 511 of the solenoid valve is connected to the capillary tube 61, and the second outlet 512 is connected to the inlet of the bypass pipe 81. The solenoid valve 51 can be an electric rotary valve or a bistable solenoid valve, which have one inlet and two outlets. The solenoid valve can select the outlet through which the refrigerant flows as needed. Figure 2 This application provides a scenario diagram of a refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting.

[0110] In addition, to control the refrigeration operation of the refrigerator, this embodiment is equipped with a main control board to control the operation of components such as the refrigerator compressor and solenoid valves; the main control board is equipped with control modules for the opening and closing of various temperature sensors, compressor, and solenoid valve outlets; the operating control status of various components during evaporator defrosting is shown in Table 1:

[0111] Table 1

[0112]

[0113] The laboratory energy consumption test conditions were as follows: the refrigerator was tested according to the standard GB / T8059 "Household and Similar Refrigeration Appliances". During the process, the defrosting increment was calculated. Based on the actual test results, hot gas defrosting combined with electric heating was used for evaporator defrosting. The defrosting effect is shown in Table 2.

[0114] Table 2

[0115]

[0116]

[0117] The air-cooled refrigerator / freezer operates at 25℃ (the ambient temperature in this example is only for illustrative purposes). Based on the control board's pre-stored threshold of 12 hours for cumulative compressor operation time, when this condition is met to trigger evaporator defrosting:

[0118] Keep the compressor running, switch the solenoid valve to the bypass line, and let the high-temperature gaseous refrigerant directly rush to the evaporator;

[0119] We can assume that the frost thickness detected by the frost thickness sensor at the start of hot gas defrosting is 2.5 mm, and the instantaneous evaporator temperature is -24℃. Therefore, the basic hot gas defrosting time = 2.5 mm × 2 min / mm = 5 min. During hot gas defrosting, the real-time evaporator temperature slowly rises due to the impact of the heat from the cooling air in the condenser. The corrected hot gas defrosting time is: T actual =T base ×(1+(-18-t evp ) / 18)=5×(1+(-18-(-24)) / 18);

[0120] ≈5×1.33≈6.7min (rounded to one decimal place);

[0121] The 6.7 minutes calculated using the above formula is the maximum time for hot air defrosting. Combining this with the temperature data obtained from the evaporator temperature sensor, the following situation will occur:

[0122] T actual It reached 6.7 minutes, while T evp <0℃;

[0123] or T evp Reaching 0℃, while T actual <6.7min;

[0124] T actual Reaching 6.7 minutes or T evp =0℃, at which point the compressor stops and enters the electric heating defrosting stage, at which point the compressor stops and the electric heater starts;

[0125] Refrigerator evaporator heaters are typically 120-250W, and operate before reaching the temperature threshold. max Before reaching 8℃, variable power heating is used. Assuming the rated power of the refrigerator evaporator is 180W, and K is empirically chosen as 2, then:

[0126] P heater =P 额定 ×(t max -t evp +k) / t max = 180 × (8 - +2) / 8;

[0127] =180×(10-t) evp ) / 8;

[0128] After each temperature is detected, the power is calculated and maintained for 1 minute. The 0th minute is defined as the starting time of electric heating. At the start of heating, tevp = 0. The power change during the heating process is shown in Table 3.

[0129] Table 3

[0130]

[0131] Heating is performed at 67.5W at the 8th minute. When the running time is less than 1 minute, the TEVP reaches the threshold of 8℃, the electric heating stops, the dripping time begins, and then the normal cooling process begins.

[0132] As can be seen from the above embodiments, this application provides a refrigerator system and method based on condensation heat recovery and asynchronous collaborative defrosting. The method includes sending a defrosting command when the frost thickness detected by the frost thickness sensor is ≥3mm, or the cumulative compressor running time recorded by the main control board is ≥ a preset running threshold, and the compressor is in operation; after receiving the defrosting command, controlling the three-way solenoid valve to switch to the second outlet open and the first outlet closed, so that the refrigerant flows into the evaporator through the defrosting bypass pipeline, and keeping the compressor running continuously; when the instantaneous temperature of the evaporator is 0℃, stopping the compressor operation; the main control board starts the steel pipe heater and adjusts the power of the steel pipe heater according to the instantaneous temperature of the evaporator detected by the temperature sensor; when the instantaneous temperature of the evaporator detected by the temperature sensor reaches the temperature threshold, turning off the steel pipe heater, ending the defrosting command, and the refrigerator returns to normal cooling mode. This application adds a one-in-two-out solenoid valve to the refrigerator's refrigeration system. During defrosting, the continuous operation of the compressor and the change in the solenoid valve outlet allow heat from the condenser to be continuously transferred to the evaporator for defrosting, reducing the heating energy of the electric heater and achieving the goal of reducing refrigerator energy consumption while ensuring defrosting reliability.

[0133] Similar parts between the embodiments provided in this application can be referred to mutually. The specific implementation methods provided above are only a few examples under the overall concept of this application and do not constitute a limitation on the scope of protection of this application. For those skilled in the art, any other implementation methods extended from the solution of this application without creative effort shall fall within the scope of protection of this application.

Claims

1. A refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting, characterized in that, Including the refrigeration system and the defrosting system; The refrigeration system consists of a compressor, condenser, filter, three-way solenoid valve, anti-condensation tube, capillary tube, evaporator, and a defrosting bypass pipeline. The outlet of the condenser is connected to the inlet of the filter, the outlet of the filter is connected to the inlet of the three-way solenoid valve, the first outlet of the three-way solenoid valve is connected to the inlet of the capillary tube, the outlet of the capillary tube is connected to the inlet of the evaporator, the second outlet of the three-way solenoid valve is connected to the inlet of the defrosting bypass pipeline, the outlet of the defrosting bypass pipeline is connected to the inlet of the evaporator, and the anti-condensation tube is integrated into the refrigerant flow path of the refrigeration system. The defrosting system includes a main control board, a temperature sensor, a frost thickness sensor, and a steel pipe heater. The main control board is equipped with a control module for controlling the operation of the compressor, a three-way solenoid valve, and the steel pipe heater. The temperature sensor is installed at the inlet or outlet of the evaporator to detect the instantaneous temperature of the evaporator. The frost thickness sensor is installed on the surface of the evaporator to detect the frost thickness. The steel pipe heater is located at the bottom of the evaporator to assist in defrosting.

2. The refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting according to claim 1, characterized in that, The three-way solenoid valve is an electric rotary valve or a bistable solenoid valve. The three-way solenoid valve includes an inlet, a first outlet, and a second outlet. The solenoid valve is used to select the outlet through which the refrigerant flows according to requirements.

3. The refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting according to claim 2, characterized in that, The refrigerant flow path of the refrigeration system has two conduction states: The first conduction state is from the compressor, condenser, filter, three-way solenoid valve, capillary tube to evaporator; The second conduction state is from the compressor, condenser, filter, three-way solenoid valve, and defrost-specific bypass line to the evaporator.

4. The refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting according to claim 3, characterized in that, The control module is configured as follows: When the frost thickness detected by the frost thickness sensor is ≥3mm, or the cumulative compressor running time recorded by the main control board is ≥ the preset running threshold, and the compressor is in operation, a defrosting command is sent. Upon receiving a defrost command, the three-way solenoid valve is switched to open the second outlet and close the first outlet, allowing refrigerant to flow into the evaporator through the dedicated defrost bypass line, and keeping the compressor running continuously. The compressor stops operating when the instantaneous temperature of the evaporator reaches 0°C. The main control board starts the steel pipe heater and adjusts the power of the steel pipe heater according to the real-time temperature of the evaporator detected by the temperature sensor. When the evaporator temperature detected by the temperature sensor reaches the temperature threshold, the steel pipe heater is turned off, the defrosting command ends, and the refrigerator returns to normal cooling mode.

5. The refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting according to claim 4, characterized in that, After the refrigerant flows into the evaporator through the dedicated defrosting bypass line, the control module is further configured to: The base runtime and corrected runtime of the compressor are calculated based on the frost layer thickness. When the compressor's operating time equals the corrected operating time, the compressor operation is stopped. If the evaporator temperature reaches 0°C first, the compressor will stop running immediately, regardless of whether the corrected operating time has been reached.

6. The refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting according to claim 4, characterized in that, The control module is also configured to: After the defrosting command ends, the refrigerator enters the dripping time. After the dripping time ends, the main control board controls the three-way solenoid valve to switch to the first outlet open and the second outlet closed, starts the compressor and evaporator fan, and the refrigerator returns to normal cooling mode.

7. The refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting according to claim 4, characterized in that, The control module is also configured to: The compressor's exhaust temperature is collected in real time. If the exhaust temperature is ≥90℃, the three-way solenoid valve is controlled to switch to the first outlet. After the exhaust temperature drops to 80℃, it is switched back to the second outlet.

8. The refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting according to claim 4, characterized in that, The control module is also configured to: Obtain the external ambient temperature of the refrigerator as detected by the ambient temperature sensor; When the external ambient temperature of the refrigerator is ≥30℃, the cumulative compressor running time threshold will be lowered by 10%-15%; when the external ambient temperature of the refrigerator is ≤5℃, the cumulative compressor running time threshold will be raised by 10%-15%.

9. The refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting according to claim 4, characterized in that, The control module is also configured to: If the temperature sensor detects that the evaporator temperature does not rise or rises by ≤1℃ within 5 minutes after starting the steel pipe heater on the main control board, it is determined to be a defrosting abnormality. The power of the steel pipe heater is adjusted to the rated power, and a fault prompt signal is sent to the refrigerator display panel.

10. A method for controlling condensation heat recovery and asynchronous collaborative defrosting, characterized in that, The method is applied to the refrigerator system based on condensation heat recovery and asynchronous collaborative defrosting as described in any one of claims 1-9; The method includes: When the frost thickness detected by the frost thickness sensor is ≥3mm, or the cumulative compressor running time recorded by the main control board is ≥ the preset running threshold, and the compressor is in operation, a defrosting command is sent. Upon receiving a defrost command, the three-way solenoid valve is switched to open the second outlet and close the first outlet, allowing refrigerant to flow into the evaporator through the dedicated defrost bypass line, and keeping the compressor running continuously. The compressor stops operating when the instantaneous temperature of the evaporator reaches 0°C. The main control board starts the steel pipe heater and adjusts the power of the steel pipe heater according to the real-time temperature of the evaporator detected by the temperature sensor. When the evaporator temperature detected by the temperature sensor reaches the temperature threshold, the steel pipe heater is turned off, the defrosting command ends, and the refrigerator returns to normal cooling mode.

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