Defrosting method, device, equipment, medium and product based on three-medium heat exchanger

Abstract

The application discloses a defrosting method, device, equipment, medium and product based on a three-medium heat exchanger. The method comprises the following steps: obtaining the operation mode of a heat pump system based on a three-medium heat exchanger, the motor loop water temperature, the compressor suction temperature and the ambient temperature; when the above parameters meet the first preset condition, determining the frosting condition of the three-medium heat exchanger according to the ambient temperature, the motor loop water temperature and the compressor suction temperature; if it is determined that the three-medium heat exchanger is frosted, controlling the three-medium heat exchanger to enter the defrosting mode and recording the defrosting duration; and when the motor loop water temperature and the defrosting duration meet the second preset condition, exiting the defrosting mode. According to the technical scheme, the temperature comparison is carried out on the three mediums, i.e. the refrigerant, the cooling liquid and the air in the multiple flow channels of the three-medium heat exchanger, the early accurate determination of the frosting of the heat exchanger and the intelligent control of the defrosting are realized, and the low-temperature adaptability, the heat exchange efficiency and the operation reliability of the heat pump system are improved.

Description

Technical Field

[0001] This application relates to the field of heat pump technology, and in particular to a defrosting method, apparatus, equipment, medium and product based on a three-medium heat exchanger. Background Technology

[0002] In new energy vehicles, heat pump systems are seeing increasing adoption rates due to their advantages such as wide temperature range, high integration, and reduced energy consumption. The outdoor heat exchanger is a key component of the heat pump system. Under low-temperature and high-humidity conditions, when the outdoor heat exchanger operates as an evaporator, its surface temperature easily falls below the air dew point and even below 0°C. Water vapor in the air condenses on the fins and flow channels, forming a frost layer. This frost layer significantly increases airflow resistance, reduces the heat transfer coefficient, leads to a decrease in the heat pump system's heating capacity, and increases compressor power consumption. In severe cases, it can even trigger high-pressure protection and system shutdown, directly impacting vehicle comfort and driving safety.

[0003] Current mainstream frosting detection and defrosting control solutions in the industry generally employ the addition of differential pressure sensors at the air inlet and outlet of the outdoor heat exchanger. By monitoring the changes in differential pressure as air flows through the heat exchanger in real time, the degree of airflow attenuation is indirectly calculated, thereby determining the degree of frosting and triggering the defrosting logic. Although this solution has been implemented in engineering applications, it has significant limitations in the complex driving scenarios of new energy vehicles: fluctuations in vehicle wind speed, fan speed disturbances, high-altitude and low-pressure environments, and dust / debris blockage on the fins can all cause distortion of the differential pressure signal, making it impossible to accurately distinguish between "real frosting" and "disturbing differential pressure changes." At the same time, the differential pressure sensor is an additional component, increasing the complexity of pipeline layout, cost, and potential failure points, and its long-term reliability is insufficient under vehicle vibration and alternating temperature and humidity environments.

[0004] As new energy vehicles upgrade towards lightweighting, integration, and intelligence, three-medium heat exchangers, which integrate refrigerant, coolant, and air heat exchange channels, are gradually becoming the core heat exchange component of vehicle heat pump systems due to their advantages of compact structure, high heat exchange efficiency, and flexible coupling of motor thermal management, battery thermal management, and cabin heating. Traditional frosting and defrosting control methods based on outdoor heat exchanger differential pressure detection cannot adapt to the multi-channel coupling and strong heat exchange correlation of three-medium heat exchangers. This makes it difficult to achieve early and accurate identification of frosting and efficient control of the defrosting process, thus restricting the performance and reliability of vehicle heat pump systems in low-temperature environments. Therefore, there is an urgent need for a frosting and defrosting control method that is compatible with three-medium heat exchangers, eliminates reliance on differential pressure sensors, and provides accurate and robust detection. Summary of the Invention

[0005] This application provides a defrosting method, apparatus, equipment, and medium based on a three-medium heat exchanger. This method achieves early and accurate detection of the frosting state and intelligent control of the defrosting process by modeling and identifying the multi-medium temperature parameters of the three-medium heat exchanger itself, without relying on differential pressure sensors. It fundamentally solves the defects of the prior art and improves the low-temperature adaptability, heat exchange efficiency, and operational reliability of the heat pump system of new energy vehicles.

[0006] According to one aspect of this application, a defrosting method based on a three-medium heat exchanger is provided, the method comprising: To obtain the operating mode, motor circuit water temperature, compressor suction temperature, and ambient temperature of a heat pump system based on a three-medium heat exchanger; When the ambient temperature, the motor circuit water temperature, the compressor suction temperature, and the operating mode meet the first preset conditions, the frosting condition of the three-medium heat exchanger is determined based on the ambient temperature, the motor circuit water temperature, and the compressor suction temperature. If it is determined that the three-medium heat exchanger is frosted, the heat pump system is controlled to enter defrost mode, and the defrost duration is recorded. When the water temperature in the motor circuit and the defrosting time meet the second preset conditions, the defrosting mode is exited.

[0007] According to another aspect of this application, a defrosting device based on a three-medium heat exchanger is provided, characterized in that the device comprises: The parameter acquisition module is used to acquire the operating mode, motor circuit water temperature, compressor suction temperature and ambient temperature of the heat pump system based on the three-medium heat exchanger. The frosting determination module is used to determine the frosting status of the three-medium heat exchanger based on the ambient temperature, the motor circuit water temperature, the compressor suction temperature, and the operating mode when the ambient temperature, the motor circuit water temperature, the compressor suction temperature, and the operating mode meet the first preset conditions. The defrosting control module is used to control the heat pump system to enter defrosting mode if it is determined that the three-medium heat exchanger is frosted, and to record the defrosting duration. The defrost exit module is used to exit the defrost mode when the water temperature in the motor circuit and the defrost duration meet the second preset conditions.

[0008] According to another aspect of this application, an electronic device is provided, the device comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the defrosting method based on a three-medium heat exchanger as described in any embodiment of this application.

[0009] According to another aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium storing computer instructions for causing a processor to execute and implement the defrosting method based on a three-medium heat exchanger as described in any embodiment of this application.

[0010] According to another aspect of this application, a computer program product is provided, the computer program product comprising a computer program that, when executed by a processor, implements the defrosting method based on a three-medium heat exchanger as described in any embodiment of this application.

[0011] The technical solution provided in this application acquires the operating mode, motor circuit water temperature, compressor suction temperature, and ambient temperature of a heat pump system based on a three-medium heat exchanger. When the above parameters meet a first preset condition, the frosting status of the three-medium heat exchanger is determined based on the ambient temperature, motor circuit water temperature, and compressor suction temperature. If frosting is determined, the three-medium heat exchanger is controlled to enter defrosting mode and the defrosting duration is recorded. When the motor circuit water temperature and defrosting duration meet a second preset condition, the defrosting mode is exited. This technical solution achieves early and accurate determination of heat exchanger frosting and intelligent defrosting control by comparing the temperatures of the refrigerant, coolant, and air in the multi-channel system of the three-medium heat exchanger, thereby improving the low-temperature adaptability, heat exchange efficiency, and operational reliability of the heat pump system.

[0012] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a flowchart of a defrosting method based on a three-medium heat exchanger, provided in Embodiment 1 of this application.

[0015] Figure 2 This is a flowchart of a defrosting method based on a three-medium heat exchanger, provided in Embodiment 2 of this application.

[0016] Figure 3 This is a schematic diagram of a defrosting device based on a three-medium heat exchanger provided in Embodiment 3 of the present invention.

[0017] Figure 4 This is a schematic diagram of the structure of a device for implementing a defrosting method based on a three-medium heat exchanger according to an embodiment of this application. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0019] It should be noted that the terms "first," "second," "third," "calibrated," "preset," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0020] It should also be noted that the acquisition, storage, use, and processing of data in the technical solution of this application all comply with the relevant provisions of national laws and regulations.

[0021] Example 1 Figure 1 This is a flowchart illustrating a defrosting method based on a three-medium heat exchanger, provided in Embodiment 1 of this application. This embodiment is applicable to defrosting heat pump systems based on three-medium heat exchangers. The method can be executed by a defrosting device based on a three-medium heat exchanger, which can be implemented in hardware and / or software. This defrosting device can be configured in a device with data processing capabilities. Figure 1 As shown, the method includes the following steps.

[0022] S110. Obtain the operating mode, motor circuit water temperature, compressor suction temperature, and ambient temperature of the heat pump system based on the three-medium heat exchanger.

[0023] A three-medium heat exchanger is a heat exchanger consisting of three independent channels through which different media flow, enabling complex heat exchange through three media at different temperatures to achieve multiple operating modes. In this application, the three-medium heat exchanger integrates three heat exchange channels for refrigerant, coolant, and air.

[0024] A heat pump system based on a three-medium heat exchanger refers to a system consisting of a three-medium heat exchanger, an evaporator / condenser, an expansion valve, a water pump, and other components. Its operating modes include heating mode, cooling mode, defrosting mode, and hot gas bypass mode.

[0025] In heating mode, the three-medium heat exchanger operates as an evaporator, where the low-temperature, low-pressure refrigerant evaporates in the flow channel, and heat exchange with the higher-temperature medium can be intelligently regulated. When the motor does not generate sufficient waste heat, the three-medium heat exchanger acts as a refrigerant-air heat exchanger; when the motor generates sufficient waste heat, it acts as a refrigerant-coolant heat exchanger. In defrosting mode, the three-medium heat exchanger can be the object being heated. The system bypasses hot gas, directly introducing some of the high-temperature, high-pressure gas discharged from the compressor to the compressor suction side, raising the compressor suction temperature (i.e., the refrigerant temperature) to above 0°C. At this point, the tube wall temperature of the three-medium heat exchanger is determined by the refrigerant temperature. When the tube wall temperature rises above 0°C, the frost layer melts into water from the bottom; alternatively, the motor actively heats the coolant, which then heats the heat exchanger core through the coolant flow channel. In cooling mode, the three-medium heat exchanger can operate as part of a condenser or subcooler, where the high-temperature, high-pressure refrigerant releases heat to the coolant or air, achieving a refrigeration cycle. In hot gas bypass mode, the three-medium heat exchanger still acts as an evaporator. The compressor exhaust is directly short-circuited back to the suction side through the bypass valve, which will rapidly increase the compressor's suction pressure and suction temperature. When the compressor suction temperature is above 0°C, the three-medium heat exchanger itself no longer has the temperature conditions for frosting.

[0026] This application primarily addresses the situation where, during vehicle heating in winter, the three-medium heat exchanger in the heat pump system operates as an evaporator. When the surface temperature of the three-medium heat exchanger is lower than the air dew point temperature and below 0°C, water vapor in the air condenses on the fins and flow channel surfaces, forming a frost layer. Therefore, frost detection and defrosting control should only begin when the heat pump system is in heating mode.

[0027] Therefore, the operating mode of the heat pump system, the water temperature in the motor circuit, the suction temperature of the compressor, and the ambient temperature can be collected periodically according to the preset collection cycle.

[0028] The operating mode can be determined by instructions received by the heat pump controller from the vehicle controller, air conditioning panel, battery management system, etc. For example, in response to the operation of the passenger on the air conditioning panel, the operation command is sent to the heat pump controller to trigger the corresponding operating mode.

[0029] Ambient temperature refers to the temperature of the air flowing outside the fins of the three-medium heat exchanger when the heat pump system is operating; that is, the air temperature inside the three-medium heat exchanger. It represents the temperature of the low-temperature heat source from which the heat pump system attempts to extract heat. A temperature sensor is installed near the windward side of the three-medium heat exchanger inside the vehicle's front compartment (usually behind the front bumper grille) to obtain the ambient temperature.

[0030] The motor circuit coolant temperature refers to the temperature of the motor coolant flowing through the internal coolant channels of the three-medium heat exchanger; that is, the coolant temperature within the three-medium heat exchanger. In heat pump heating mode, the motor coolant acts as an intermediate medium, absorbing heat from the air in the three-medium heat exchanger and then releasing that heat to the passenger compartment at the vehicle's condenser. This temperature reflects the actual state of the coolant side after heat exchange with the air. Specifically, a temperature sensor can be installed in the motor cooling circuit, immediately adjacent to the coolant inlet or outlet pipe of the three-medium heat exchanger, to obtain the motor circuit coolant temperature.

[0031] The compressor suction temperature refers to the temperature of the refrigerant when it enters the compressor suction port, i.e., the refrigerant in the three-medium heat exchanger. When the three-medium heat exchanger operates as an evaporator, this temperature is approximately equal to the temperature at which the refrigerant has completely evaporated inside the heat exchanger. It directly reflects the heat absorption state and superheat of the refrigerant in the heat exchanger. Specifically, a temperature sensor can be installed on the refrigerant line near the compressor suction port to obtain the compressor suction temperature.

[0032] The three physical quantities—motor circuit water temperature, compressor suction temperature, and ambient temperature—correspond to the three media involved in heat exchange in the three-medium heat exchanger: coolant, refrigerant, and air. This application uses continuous monitoring and analysis of the dynamic relationship between these three parameters to accurately determine whether frost has formed on the surface of the three-medium heat exchanger.

[0033] S120. When the ambient temperature, the motor circuit water temperature, the compressor suction temperature, and the operating mode meet the first preset conditions, determine the frosting status of the three-medium heat exchanger based on the ambient temperature, the motor circuit water temperature, and the compressor suction temperature.

[0034] The first preset condition is the prerequisite for determining whether to perform a frosting assessment. Specifically, a threshold can be initially set based on thermodynamic principles; then, different temperatures and humidity levels can be simulated in an environmental chamber to observe the frosting conditions of the three-medium heat exchanger; finally, the frosting conditions can be optimized through full-vehicle road testing, such as collecting a large amount of actual driving data.

[0035] In some embodiments, optionally, the first preset conditions include: the water temperature in the motor circuit is less than or equal to a first preset temperature, the water temperature in the motor circuit is less than the ambient temperature, the air intake temperature of the compressor is less than the ambient temperature, the operating mode is a heating mode and not a hot gas bypass mode, and the heat pump system is not in a defrosting mode.

[0036] It is understandable that water vapor in the air can only condense and frost on the surface of a three-medium heat exchanger when the temperature of the coolant flowing through the heat exchanger is lower than the air dew point temperature and close to the freezing point. The water temperature in the motor circuit is less than or equal to a first preset temperature to eliminate high-temperature operating conditions. In this application, the first preset temperature can be 0°C.

[0037] According to basic thermodynamic principles, heat can only be transferred from the air to the coolant if the coolant temperature in the three-medium heat exchanger is lower than the air temperature; that is, the motor circuit water temperature must be lower than the ambient temperature. If the motor circuit water temperature is greater than or equal to the ambient temperature, there is no risk of frost formation.

[0038] According to basic thermodynamic principles, heat can only be transferred from the air to the refrigerant if the refrigerant evaporation temperature is lower than the air temperature, meaning the compressor suction temperature is lower than the ambient temperature. This is a prerequisite for the heat pump to function properly. If the compressor suction temperature is greater than or equal to the ambient temperature, it indicates that the heat pump system may not be operating at its optimal heating capacity.

[0039] In a heat pump system, the three-medium heat exchanger only operates as an evaporator in heating mode, absorbing heat from the air, thus providing the physical basis for frost formation. The non-hot gas bypass mode and non-defrost mode are used to prevent repeated defrosting cycles and are a state interlock mechanism.

[0040] The aforementioned limitations on the first preset condition can quickly eliminate most operating conditions that are unlikely to frost, providing reliable data support for the subsequent frost determination algorithm.

[0041] When the first preset condition is met, the frosting determination logic is initiated. Specifically, the relationship between ambient temperature, motor circuit water temperature, and compressor suction temperature is compared to determine whether the three-medium heat exchanger is frosted.

[0042] S130. If it is determined that the three-medium heat exchanger is frosted, the heat pump system is controlled to enter the defrosting mode, and the defrosting time is recorded.

[0043] Defrosting mode refers to a combination of preset control actions. Its purpose is to quickly and efficiently remove the frost layer on the surface of the heat exchanger, restore its heat exchange capacity, and at the same time minimize the impact on the comfort of the passenger cabin.

[0044] In this application, the defrosting mode can be determined based on the configuration features of the actual vehicle. For example, if the vehicle is equipped with a hot gas bypass valve, the defrosting mode may include hot gas bypass circulation, which guides the high-temperature refrigerant discharged from the compressor through the three-medium heat exchanger for defrosting, and usually needs to be combined with the air heater to maintain the heating inside the vehicle. If the vehicle integrates a motor waste heat recovery system, the defrosting mode can be upgraded to a combination of hot gas bypass and active motor heating. During defrosting, the system can control the motor to operate in the inefficient zone to generate additional heat. This heat is absorbed by the coolant and can be used to help increase the temperature of the three-medium heat exchanger or directly heat the passenger compartment, thereby reducing dependence on the air heater and improving energy efficiency. If the vehicle has a more advanced thermal management architecture, such as integrating a battery thermal management circuit and a multi-way valve, the defrosting mode can be expanded to a multi-heat source intelligent coupling mode. The system can dynamically distribute and deliver heat to the three-medium heat exchanger through valve adjustment according to the real-time heat source status and heat demand, achieving globally optimal defrosting and thermal management.

[0045] Defrosting time refers to the cumulative time elapsed from the moment a heat pump system enters defrosting mode until the exit conditions are met and the system exits. Defrosting time can be used to determine if defrosting is sufficient and to prevent the defrosting process from going on indefinitely due to sensor malfunctions or logic errors.

[0046] In some embodiments, optionally, controlling the heat pump system to enter defrost mode includes: if there is an active motor heating function, controlling the heat pump system to turn on active motor heating and setting the target temperature of the motor circuit water temperature to a third preset temperature; and if there is a hot air bypass function, controlling the heat pump system to switch to hot air bypass mode; and if there is an active air intake grille, controlling the heat pump system to close the active air intake grille; and controlling the heat pump system to stop the cooling fan.

[0047] The motor active heating function means that when the motor is running, it operates in a slightly less efficient mode, thereby generating additional heat, which is carried away by the motor's coolant.

[0048] The third preset temperature is the target temperature of the motor circuit water, i.e., the coolant temperature of the three-medium heat exchanger, used to assist defrosting and maintain basic heating. In this application, the third preset temperature can be set to 10℃ to balance defrosting efficiency and system energy consumption. When the 10℃ coolant flows through the coolant channels inside the three-medium heat exchanger, it can effectively transfer heat to the metal wall of the heat exchanger to assist defrosting; at the same time, the 10℃ coolant does not require the motor to consume a large amount of electrical energy to continuously generate a high heat load, thus avoiding increasing the overall energy consumption of the defrosting process.

[0049] When the vehicle has an active motor heating function, a command is sent to the motor controller to activate the active motor heating function.

[0050] Hot gas bypass function refers to bypassing the high-temperature gaseous refrigerant at the high-pressure end to the low-pressure end of the system, ensuring that the system always maintains stable operation at a preset minimum return gas pressure.

[0051] When the vehicle has a hot gas bypass function, the control heat pump system switches to hot gas bypass mode. The hot gas bypass valve opens, and some of the high-temperature and high-pressure gas discharged from the compressor is directly introduced into the compressor suction side, so that the compressor suction temperature, i.e. the refrigerant temperature, rises to above 0°C. At this time, the tube wall temperature of the three-medium heat exchanger is determined by the refrigerant temperature. When the tube wall temperature rises to above 0°C, the frost layer melts into water from the bottom.

[0052] An active grille shutter refers to a grille at the front of a vehicle that can automatically adjust its opening and closing angle. When the grille is closed, the amount of cold air entering the engine compartment from the front of the vehicle and flowing across the surface of the three-medium heat exchanger is significantly reduced, allowing the heat provided by the motor and compressor to be more concentrated for defrosting, thereby significantly improving defrosting efficiency.

[0053] When a vehicle is equipped with an active grille shutter, the system sends a command to the drive motor of the active grille shutter to adjust its blades to a fully or nearly fully closed state.

[0054] A cooling fan is a fan assembly driven by an electric motor installed in the front engine compartment of a vehicle. It is used to generate forced airflow according to control commands to provide forced ventilation and cooling for radiator modules (such as radiators, condensers, and three-medium heat exchangers).

[0055] Under normal cooling or heat dissipation conditions, the system adjusts the fan speed based on signals such as refrigerant pressure and coolant temperature to control the airflow across the heat exchanger surface and ensure heat dissipation efficiency. In defrost mode, the system stops the fan to minimize the flow of cold air and prevent the heat used for defrosting from being carried away by forced convection, thereby achieving heat preservation and improving defrosting efficiency.

[0056] It should be noted that after the heat pump system enters defrost mode, the above actions are performed simultaneously to improve defrost efficiency.

[0057] S140. When the water temperature in the motor circuit and the defrosting time meet the second preset conditions, exit the defrosting mode.

[0058] Understandably, defrosting is an energy-consuming process that temporarily sacrifices heating capacity. If defrosting is insufficient, the remaining frost layer will continue to hinder heat exchange, reduce heating efficiency, and increase energy consumption. On the other hand, excessive defrosting means unnecessary energy waste and a longer interruption of heating in the vehicle, affecting comfort. Therefore, the control strategy needs to find the optimal balance between insufficient and excessive defrosting.

[0059] The second preset condition refers to the logical judgment rule used during the defrosting process of the heat pump system to determine whether defrosting is complete, thereby controlling the system to exit the defrosting mode and resume normal operation. In this application, it can be triggered by comparing the motor circuit water temperature and defrosting duration with the second preset condition.

[0060] In defrost mode, the heat generated by the motor and the heat from the refrigerant hot gas bypass are used together to heat the three-medium heat exchanger. Once the frost layer on the surface of the three-medium heat exchanger has largely melted, the input heat will be used more to raise the temperature of the three-medium heat exchanger itself and its internal coolant. Therefore, the significant and stable rise in the motor circuit water temperature is direct evidence that the frost layer on the three-medium heat exchanger has melted and the thermal resistance has decreased.

[0061] As a time measure of the process, the defrosting time ensures that even if the water temperature signal rises slowly due to the extremely cold environment, the minimum defrosting time is guaranteed to prevent instantaneous shutdown. On the other hand, it also prevents the system from being in defrosting mode indefinitely due to a water temperature sensor malfunction.

[0062] Specifically, the defrosting mode can be exited when the water temperature in the motor circuit reaches a certain temperature and the defrosting time reaches a certain duration.

[0063] In some embodiments, the second preset condition may optionally include: the water temperature in the motor circuit reaches a second preset temperature and remains there for a first preset duration, or the defrosting duration reaches a second preset duration.

[0064] In this application, the second preset temperature can be 5°C, the first preset duration can be 5 minutes, and the second preset duration can be 10 minutes. Defrosting will stop when the water temperature in the motor circuit reaches 5°C and remains there for 5 minutes, or when the defrosting duration reaches 10 minutes.

[0065] Under normal circumstances, the defrosting mode will be precisely exited when the motor circuit water temperature reaches 5°C and remains there for 5 minutes. Only in rare abnormal situations, when the defrosting duration reaches 10 minutes, will the system act as a safety valve to ensure it returns to a controllable state.

[0066] The above technical solution balances efficiency, comfort, and reliability, aiming to complete defrosting quickly and energy-efficiently under normal conditions, while providing solid protection for all possible abnormal situations.

[0067] This invention provides a defrosting method based on a three-medium heat exchanger. The method acquires the operating mode of the heat pump system based on the three-medium heat exchanger, the motor circuit water temperature, the compressor suction temperature, and the ambient temperature. When the above parameters meet a first preset condition, the frosting status of the three-medium heat exchanger is determined based on the ambient temperature, motor circuit water temperature, and compressor suction temperature. If frosting is determined, the three-medium heat exchanger is controlled to enter defrosting mode and the defrosting duration is recorded. When the motor circuit water temperature and defrosting duration meet a second preset condition, the defrosting mode is exited. This technical solution, by comparing the temperatures of the refrigerant, coolant, and air in the multi-channel system of the three-medium heat exchanger, achieves early and accurate determination of heat exchanger frosting and intelligent defrosting control, improving the low-temperature adaptability, heat exchange efficiency, and operational reliability of the heat pump system.

[0068] Example 2 Figure 2 This is a flowchart of a defrosting method based on a three-medium heat exchanger provided in Embodiment 2 of this application. This embodiment is an optimization based on the above embodiment, specifically optimizing the frosting determination process. Figure 2 As shown, the method in this embodiment specifically includes the following steps.

[0069] S210. Obtain the operating mode, motor circuit water temperature, compressor suction temperature, and ambient temperature of the heat pump system based on the three-medium heat exchanger.

[0070] S220. When the ambient temperature, the motor circuit water temperature, the compressor suction temperature, and the operating mode meet the first preset conditions, determine the first difference based on the ambient temperature and the motor circuit water temperature.

[0071] Specifically, the first difference can be expressed by the following formula: ; In the formula, Indicates the first difference. Indicates ambient temperature. This indicates the water temperature in the motor circuit.

[0072] The first difference reflects the temperature difference between the ambient temperature and the motor circuit water temperature. In a low temperature and high humidity environment, the first difference gradually increases, indicating that the three-medium heat exchanger may absorb less heat from the air and more heat from the coolant due to slight frost.

[0073] S230. Determine the second difference based on the ambient temperature and the compressor suction temperature.

[0074] Specifically, the second difference can be expressed by the following formula: ; In the formula, Indicates the second difference. This indicates the compressor's suction temperature.

[0075] The second difference reflects the temperature difference between the ambient and the refrigerant. Under normal circumstances, the evaporator exchanges heat efficiently, and the refrigerant temperature is close to the ambient temperature. However, when frost forms, the frost layer hinders the heat exchange between the air and the evaporator, resulting in a reduction in the heat absorbed by the three-medium heat exchanger from the air, and the refrigerant temperature gradually decreases.

[0076] S240. When the ratio of the first difference to the second difference is greater than the calibration parameter, start timing to determine the warning duration.

[0077] It is understandable that the ratio of the first difference to the second difference, i.e. The ratio reflects the proportion of heat exchanged from the coolant in a three-medium heat exchanger. When frosting begins, the frost layer hinders heat exchange between the air and the heat exchanger, resulting in less heat absorption by the refrigerant from the air and more heat absorption from the coolant. The coolant temperature gradually decreases, and the refrigerant temperature changes slowly, thus the ratio gradually increases. When frosting is severe, the refrigerant can hardly absorb heat from the air and only absorbs heat from the coolant. At this time, the refrigerant temperature and the coolant temperature are close and much lower than the ambient temperature, so the ratio gradually approaches 1.

[0078] To avoid single misjudgments caused by interference such as instantaneous fluctuations in the sensor or the vehicle briefly passing through a high-humidity area, the ratio of the first difference to the second difference must be greater than the calibration parameter for a certain period of time to ensure that the detected performance degradation is a continuous and stable trend rather than accidental interference, thereby greatly improving the reliability of the judgment.

[0079] In some embodiments, the calibration parameter may optionally range from 0.3 to 1.0.

[0080] This application, through testing on numerous different vehicle models, determined that the calibration parameter values ​​should ideally range from 0.3 to 1.0. For example, a calibration parameter range of 0.3 to 0.5 results in a more sensitive frosting detection response, better preventing excessive frost accumulation from affecting performance. However, it may also trigger unnecessary defrosting due to short-term load fluctuations or sensor noise, reducing energy efficiency and comfort. A calibration parameter range of 0.7 to 1.0 provides a more conservative frosting detection response, effectively avoiding unnecessary defrosting. However, it may also lead to delayed defrosting, excessively thick frost layers, resulting in longer defrosting times and higher energy consumption.

[0081] In actual use, due to the differences in the sensor placement on different vehicle models, the values ​​of their calibration parameters will vary slightly. The calibration parameters should be determined by testing and verification based on the actual vehicle model.

[0082] S250. If the warning duration exceeds the target duration, then it is determined that the three-medium heat exchanger is frosted.

[0083] In this application, the target duration can be 2 minutes. When the ratio of the first difference to the second difference remains greater than the calibration parameter for more than 2 minutes, frosting of the three-medium heat exchanger is determined.

[0084] S260. If it is determined that the three-medium heat exchanger is frosted, the heat pump system is controlled to enter the defrosting mode, and the defrosting time is recorded.

[0085] S270. When the water temperature in the motor circuit and the defrosting time meet the second preset conditions, exit the defrosting mode.

[0086] This invention provides a defrosting method based on a three-medium heat exchanger. This method calculates and monitors in real-time the first difference between the ambient temperature and the motor circuit water temperature, the second difference between the ambient temperature and the compressor suction temperature, and the changes in their ratios. This allows for the sensitive detection of heat exchanger performance degradation trends in the early stages of frosting. Furthermore, by introducing a comparison mechanism between the warning duration and the target duration, instantaneous interference is effectively filtered out, avoiding misjudgments. This method achieves accurate and reliable determination of the early frosting state of the three-medium heat exchanger, providing a crucial basis for timely defrosting and preventing a severe decrease in heating efficiency due to excessive frost thickness. This ensures the energy efficiency, heating stability, and overall reliability of the heat pump system in low-temperature environments.

[0087] Example 3 Figure 3 This is a schematic diagram of a defrosting device based on a three-medium heat exchanger provided in Embodiment 3 of the present invention. Figure 3 As shown, the device includes: The parameter acquisition module 310 is used to acquire the operating mode, motor circuit water temperature, compressor suction temperature and ambient temperature of the heat pump system based on the three-medium heat exchanger. The frosting determination module 320 is used to determine the frosting status of the three-medium heat exchanger based on the ambient temperature, the motor circuit water temperature, the compressor suction temperature, and the operating mode when the ambient temperature, the motor circuit water temperature, the compressor suction temperature, and the operating mode meet the first preset conditions. The defrosting control module 330 is used to control the heat pump system to enter the defrosting mode if it is determined that the three-medium heat exchanger is frosted, and to record the defrosting time. The defrosting exit module 340 is used to exit the defrosting mode when the water temperature in the motor circuit and the defrosting duration meet the second preset conditions.

[0088] The defrosting device based on a three-medium heat exchanger provided in this invention acquires the operating mode of the heat pump system based on the three-medium heat exchanger, the motor circuit water temperature, the compressor suction temperature, and the ambient temperature. When the above parameters meet a first preset condition, the frosting status of the three-medium heat exchanger is determined based on the ambient temperature, the motor circuit water temperature, and the compressor suction temperature. If frosting is determined, the three-medium heat exchanger is controlled to enter defrosting mode and the defrosting duration is recorded. When the motor circuit water temperature and the defrosting duration meet a second preset condition, the defrosting mode is exited. This technical solution achieves early and accurate determination of heat exchanger frosting and intelligent defrosting control by comparing the temperatures of the refrigerant, coolant, and air in the multi-channel of the three-medium heat exchanger, thereby improving the low-temperature adaptability, heat exchange efficiency, and operational reliability of the heat pump system.

[0089] Furthermore, the first preset conditions include: the water temperature in the motor circuit is less than or equal to the first preset temperature, the water temperature in the motor circuit is less than the ambient temperature, the air intake temperature of the compressor is less than the ambient temperature, the operating mode is heating mode and not hot gas bypass mode, and the heat pump system is not in defrosting mode.

[0090] Furthermore, the frosting determination module 320 includes: The first difference determination unit is used to determine the first difference based on the ambient temperature and the water temperature in the motor circuit; The second difference determination unit is used to determine a second difference based on the ambient temperature and the compressor suction temperature. The warning duration determination unit is used to start timing when the ratio of the first difference and the second difference is greater than the calibration parameter, and to determine the warning duration; The frosting determination unit is used to determine that the three-medium heat exchanger is frosted if the warning duration exceeds the target duration.

[0091] Furthermore, the calibration parameter has a value range of 0.3 to 1.0.

[0092] Furthermore, the second preset condition includes: the water temperature in the motor circuit reaches a second preset temperature and remains at a first preset time, or the defrosting time reaches a second preset time.

[0093] Furthermore, the defrosting control module 330 includes: The motor heating activation unit is used to control the heat pump system to activate the motor active heating function if the motor active heating function is available, and to set the target temperature of the water temperature in the motor circuit to a third preset temperature. A hot gas bypass activation unit is used to control the heat pump system to switch to hot gas bypass mode if a hot gas bypass function is available. An air intake grille closing unit is used to control the heat pump system to close the active air intake grille if an active air intake grille is present. A cooling fan stop unit is used to control the cooling fan of the heat pump system to stop.

[0094] The defrosting device based on a three-medium heat exchanger provided in this embodiment of the invention can execute the defrosting method based on a three-medium heat exchanger provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method.

[0095] Example 4 Figure 4 A schematic diagram of the structure of a device 10 that can be used to implement embodiments of this application is shown. The device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The device may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the application described and / or claimed herein.

[0096] like Figure 4 As shown, device 10 includes at least one processor 11 and a memory, such as read-only memory (ROM) 12, random access memory (RAM) 13, etc., communicatively connected to at least one processor 11. The memory stores computer programs executable by at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded into the RAM 13 from storage unit 18. The RAM 13 may also store various programs and data required for the operation of device 10. The processor 11, ROM 12, and RAM 13 are interconnected via bus 14. Input / output (I / O) interface 15 is also connected to bus 14.

[0097] Multiple components in device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of monitors, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0098] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as a defrosting method based on a three-medium heat exchanger.

[0099] In some embodiments, the defrosting method based on a three-medium heat exchanger can be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the defrosting method based on a three-medium heat exchanger described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to perform the defrosting method based on a three-medium heat exchanger by any other suitable means (e.g., by means of firmware).

[0100] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0101] Computer programs used to implement the methods of this application may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0102] In the context of this application, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium can be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0103] To provide interaction with a user, the systems and techniques described herein can be implemented on a device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0104] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or middleware components (e.g., application servers), or frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0105] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0106] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication unit 19, or installed from storage unit 18, or installed from ROM 12. When the computer program is executed by processor 11, it performs the functions defined in the methods of the embodiments of the present invention.

[0107] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this application can be achieved, and this is not limited herein.

[0108] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A defrosting method based on a three-medium heat exchanger, characterized in that, The method includes: To obtain the operating mode, motor circuit water temperature, compressor suction temperature, and ambient temperature of a heat pump system based on a three-medium heat exchanger; When the ambient temperature, the motor circuit water temperature, the compressor suction temperature, and the operating mode meet the first preset conditions, the frosting condition of the three-medium heat exchanger is determined based on the ambient temperature, the motor circuit water temperature, and the compressor suction temperature. If it is determined that the three-medium heat exchanger is frosted, the heat pump system is controlled to enter defrost mode, and the defrost duration is recorded. When the water temperature in the motor circuit and the defrosting time meet the second preset conditions, the defrosting mode is exited.

2. The method according to claim 1, characterized in that, The first preset conditions include: the water temperature in the motor circuit is less than or equal to the first preset temperature; the water temperature in the motor circuit is less than the ambient temperature; the air intake temperature of the compressor is less than the ambient temperature; the operating mode is heating mode and not hot gas bypass mode; and the heat pump system is not in defrosting mode.

3. The method according to claim 1, characterized in that, The frosting condition of the three-medium heat exchanger is determined based on the ambient temperature, the water temperature in the motor circuit, and the suction temperature of the compressor, including: The first difference is determined based on the ambient temperature and the water temperature in the motor circuit; The second difference is determined based on the ambient temperature and the compressor suction temperature; Timing begins when the ratio of the first difference to the second difference is greater than the calibration parameter, thus determining the warning duration. If the warning duration exceeds the target duration, then the three-medium heat exchanger is confirmed to be frosted.

4. The method according to claim 3, characterized in that, The calibration parameters range from 0.3 to 1.

0.

5. The method according to claim 1, characterized in that, The second preset condition includes: the water temperature in the motor circuit reaches the second preset temperature and remains at the first preset time, or the defrosting time reaches the second preset time.

6. The method according to claim 1, characterized in that, The control of the heat pump system to enter defrost mode includes: If the motor has an active heating function, the heat pump system is controlled to start the active heating of the motor, and the target temperature of the water temperature in the motor circuit is set to the third preset temperature. In addition, if there is a hot gas bypass function, the heat pump system is controlled to switch to hot gas bypass mode; And, if there is an active air intake grille, the heat pump system is controlled to close the active air intake grille; And, control the heat pump system to stop the cooling fan.

7. A defrosting device based on a three-medium heat exchanger, characterized in that, The device includes: The parameter acquisition module is used to acquire the operating mode, motor circuit water temperature, compressor suction temperature and ambient temperature of the heat pump system based on the three-medium heat exchanger. The frosting determination module is used to determine the frosting status of the three-medium heat exchanger based on the ambient temperature, the motor circuit water temperature, the compressor suction temperature, and the operating mode when the ambient temperature, the motor circuit water temperature, the compressor suction temperature, and the operating mode meet the first preset conditions. The defrosting control module is used to control the heat pump system to enter defrosting mode if it is determined that the three-medium heat exchanger is frosted, and to record the defrosting duration. The defrost exit module is used to exit the defrost mode when the water temperature in the motor circuit and the defrost duration meet the second preset conditions.

8. An electronic device, characterized in that, The device includes: At least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the defrosting method based on a three-medium heat exchanger as described in any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that, when executed by a processor, implement the defrosting method based on a three-medium heat exchanger as described in any one of claims 1-6.

10. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the defrosting method based on a three-medium heat exchanger according to any one of claims 1-6.

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