Battery thermal management system with natural cooling function, control method and automobile

Abstract

The invention discloses a battery thermal management system with a natural cooling function, a control method, an automobile and a battery cooling liquid loop, which are used for performing thermal management on a battery pack. The radiator cooling liquid loop is used for exchanging heat with ambient air; a refrigerant circulation loop for providing active cooling when activated; the mode switching device has two working states: in the first working state, the battery cooling liquid loop and the radiator cooling liquid loop are connected in parallel, and the refrigerant circulation loop is enabled or disabled to form a compressor refrigeration mode or a battery heating mode; and in a second working state, the battery cooling liquid loop and the radiator cooling liquid loop are connected in series, and the refrigerant circulation loop is forbidden, so that a natural cooling mode is formed. Different working modes are realized through the mode switching device, a natural cooling mode is used at low temperature, the battery can be efficiently cooled in a low-temperature environment, the energy consumption is reduced, and the endurance mileage is improved.

Description

Technical Field

[0001] This invention belongs to the field of battery thermal management technology, specifically relating to a battery thermal management system with natural cooling, a control method, and an automobile. Background Technology

[0002] In the application of new energy commercial vehicles, the battery thermal management system plays a crucial role in ensuring battery performance and vehicle reliability. Current mainstream systems employ independent battery cooling systems, which rely on electric compressors for active cooling. In low-temperature winter conditions, due to the large capacity and high output power of commercial vehicle batteries, driving the compressor consumes a significant amount of battery power, resulting in a substantial reduction in the vehicle's driving range. This is especially pronounced in cold seasons, where the battery's energy efficiency is suppressed by temperature, and the added energy consumption of the compressor exacerbates the range reduction problem. Furthermore, when the ambient temperature drops below -20°C, the compressor in conventional cooling units often fails to start normally due to the limitations of the working fluid. If the battery requires cooling at this time, the vehicle is forced to operate at reduced power, which not only degrades driving performance but may also cause abnormal wear and tear on core components such as the battery and motor, shortening their lifespan.

[0003] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the aforementioned background technology and provide a battery thermal management system, control method, and automobile with natural cooling. This system can efficiently cool the battery in low-temperature environments, reducing energy consumption, increasing driving range, while avoiding the problem of compressor failure to start, and simplifying the system structure.

[0005] The technical solution adopted in this invention is: a battery thermal management system with natural cooling, comprising... Battery coolant circuit, used for thermal management of the battery pack; The radiator coolant circuit is used for heat exchange with ambient air; A refrigerant circulation loop is used to provide active cooling when activated; The mode switching device has two operating states: In the first operating state, the battery coolant circuit is connected in parallel with the radiator coolant circuit, and the refrigerant circulation circuit is enabled or disabled to form a compressor cooling mode or a battery heating mode. In the second operating state, the battery coolant circuit and the radiator coolant circuit are connected in series to form a single liquid cooling circulation path, and the refrigerant circulation circuit is disabled to form a natural cooling mode.

[0006] A control method for a battery thermal management system with natural cooling as described in any of the preceding claims, comprising the following steps: Determine whether the battery pack requires cooling or heating. If cooling is required, the ambient temperature is acquired. When the ambient temperature is greater than a first threshold, the battery thermal management system with natural cooling is controlled to enter the compressor cooling mode; when the ambient temperature is less than or equal to the first threshold, the battery thermal management system with natural cooling is controlled to enter the natural cooling mode. If heating is required, the battery thermal management system with natural cooling is controlled to enter battery heating mode.

[0007] An automobile includes a battery thermal management system with natural cooling as described in any of the preceding claims.

[0008] The beneficial effects of this invention are as follows: This invention incorporates a battery cooling fluid circuit and a mode switching device to achieve different operating modes. When the low-temperature compressor cannot be started, a natural cooling mode is used to cool the battery. This enables efficient cooling of the battery in low-temperature environments, reducing energy consumption and improving driving range, energy efficiency, and the lifespan of components such as the battery and electric drive.

[0009] This invention, a thermal management system with a natural cooling module, features simple installation and easy maintenance. Maintenance can be performed without disassembling the entire unit. It meets the needs of various modes of vehicle thermal management systems while being simple to operate, convenient to maintain, time-saving, efficient, and cost-effective. Furthermore, this system integrates core functional components and control management, reducing the space required for each system and significantly improving the overall vehicle space layout efficiency. Attached Figure Description

[0010] Figure 1 This is a system architecture diagram of the present invention (also a diagram of the operating architecture in compressor refrigeration mode).

[0011] Figure 2 This is a diagram of the operating architecture under the battery heating mode of the present invention.

[0012] Figure 3 This is a diagram of the operating architecture under the natural cooling mode of the present invention.

[0013] Figure 4 A schematic diagram of the integrated unit structure for the invention.

[0014] In the diagram, 101-low temperature radiator; 102-electric fan; 103-second electric water pump; 104-water-cooled condenser; 105-liquid storage and drying tank; 106-four-way valve; 107-battery heater; 108-compressor; 109-high pressure and temperature sensor; 110-low pressure and temperature sensor; 111-battery heat exchanger; 112-electronic expansion valve; 113-first electric water pump; 114-first temperature sensor; 115-second temperature sensor; 116-battery pack; 117-integrated frame. Detailed Implementation

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments to facilitate a clear understanding of the present invention, but these descriptions do not constitute a limitation on the present invention.

[0016] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0017] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. References to "one embodiment" or "some embodiments" in this application mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized.

[0018] like Figure 1 As shown, this application proposes a battery thermal management system with natural cooling, including... The battery coolant circuit is used for thermal management of the battery pack to maintain its operation within a suitable temperature range. The radiator coolant circuit is used for heat exchange with ambient air to dissipate heat. The refrigerant circulation loop is used to provide active cooling when activated. It absorbs heat from the system through the phase change process of the refrigerant and releases it to the outside, providing a powerful cooling capacity. The mode switching device is used to change the connection method of the coolant circuit and the operating state of the refrigerant circulation circuit according to different thermal management requirements and environmental conditions, so as to realize the switching of multiple operating modes. It is configured to have at least two operating states: In the first working state, the battery coolant circuit is connected in parallel with the radiator coolant circuit, and the refrigerant circulation circuit is enabled or disabled to form a compressor cooling mode or a battery heating mode to meet high-intensity cooling or heating demands. In the second operating state, the battery coolant circuit and the radiator coolant circuit are connected in series to form a single liquid cooling circulation path, and the refrigerant circulation circuit is disabled to form a natural cooling mode. The battery pack is passively cooled mainly by heat exchange between the radiator coolant circuit and the ambient air, without the need to start the refrigerant circulation circuit.

[0019] The battery thermal management system with natural cooling proposed in this embodiment integrates multiple loops and introduces a flexible mode switching mechanism. When the ambient temperature is suitable, the system can switch to natural cooling mode, utilizing ambient air for heat dissipation and avoiding compressor activation, thereby reducing energy consumption. This system, while meeting battery thermal management requirements, improves the vehicle's driving range and ensures the service life of key components such as the battery and motor.

[0020] In one embodiment, this application further proposes a battery thermal management system with natural cooling, wherein the battery coolant circuit includes a first electronic water pump 113, a battery heat exchanger 111, a four-way valve 106, a battery heater 107, and a battery pack 116 connected in series via pipelines; the radiator coolant circuit includes a second electronic water pump 103, a low-temperature radiator 101, a four-way valve 106, and a water-cooled condenser 104 connected in series via pipelines; the refrigerant circulation circuit includes a compressor 108, a water-cooled condenser 104, a liquid storage dryer 105, an electronic expansion valve 112, and a battery heat exchanger 111 connected in series via pipelines; and the mode switching device is the four-way valve.

[0021] Specifically, the first electronic water pump 113 in the battery coolant circuit is a device that drives an impeller to rotate via electricity, thereby generating a pressure difference to flow the liquid. Its function is to drive the battery coolant to circulate in the battery coolant circuit. The battery heat exchanger 111 is a device for transferring heat between two fluids, and its function is to exchange heat between the battery coolant and the refrigerant. The four-way valve 106 is a valve with four fluid ports. By changing the position of the valve core, the flow direction can be switched and combined. Its function is to act as a mode switching device to control the connection mode of the fluid circuit. The four-way valve can be a single valve body or a combination valve body formed by multiple two-way valves or three-way valves. The battery heater 107 is a device that converts electrical energy into heat energy to heat the flowing coolant. Its function is to heat the battery coolant when needed. The inlet and outlet of the battery pack are respectively equipped with a first temperature sensor 114 and a second temperature sensor 115, which are used to detect the temperature of the inlet and outlet of the battery pack, respectively.

[0022] The second electronic water pump 103 in the radiator coolant circuit is similar to the first electronic water pump; it is also a device that uses electricity to drive the impeller to rotate and flow the liquid. Its function is to provide power in the radiator coolant circuit to drive the coolant circulation. The low-temperature radiator 101 is a device that uses ambient air as a cooling medium to dissipate the heat in the coolant to the external environment through convection and radiation. It is equipped with a matching electronic fan 102, which dissipates the heat in the coolant to the outside air. The water-cooled condenser 104 is a heat exchanger that uses coolant as a cooling medium to condense refrigerant vapor into liquid. Its function is to transfer the heat of the high-temperature, high-pressure refrigerant vapor discharged from the compressor to the coolant in the radiator coolant circuit, causing it to condense.

[0023] The compressor 108 in the refrigerant circulation loop is the core component of the loop. It compresses low-temperature, low-pressure refrigerant vapor into high-temperature, high-pressure vapor by consuming mechanical energy. Its function is to provide the power for the refrigerant circulation and to increase the pressure and temperature of the refrigerant. A low-pressure temperature sensor 110 and a high-pressure temperature sensor 109 are respectively installed at the compressor inlet and outlet. The liquid receiver-drier 105 is an auxiliary component in the refrigerant circulation loop, used to store liquid refrigerant and absorb moisture and impurities from it. Its function is to ensure that the refrigerant entering the electronic expansion valve is a pure liquid and to compensate for fluctuations in the system's refrigerant dosage. The electronic expansion valve 112 is a throttling device that precisely regulates the refrigerant flow rate through electronic control. Its function is to throttle and reduce the pressure of the high-pressure liquid refrigerant and precisely control the refrigerant flow rate according to the system load.

[0024] Through the above technical solution, this application clearly defines the key components and their series connection relationships in the battery coolant circuit, radiator coolant circuit and refrigerant circulation circuit. It not only realizes the efficient switching and precise control of the battery thermal management system in different working modes, but also improves the system integration, optimizes the cooling capacity in low-temperature environments, and reduces the system size and cost while ensuring performance. It provides a more reliable and economical thermal management solution for new energy commercial vehicles.

[0025] In one embodiment, such as Figure 1 As shown, this application further proposes a compressor cooling mode for the conventional cooling needs of the battery, for both high-temperature and normal-temperature operating conditions of the system. The specific working circuit state is as follows: compressor 108, first electronic water pump 113 and second electronic water pump 103 are turned on, and battery heater 107 is turned off.

[0026] The refrigerant circulation loop is open, and the refrigerant exchanges heat with the flowing battery coolant in the battery heat exchanger 111; The coolant in the radiator coolant circuit exchanges heat with the refrigerant in the water-cooled condenser 104, and dissipates the heat to the outside air side in the low-temperature radiator 101.

[0027] Understandably, in summer, the refrigerant circulation loop within the system involves isentropic compression of the refrigerant by an electric compressor. The refrigerant, after passing through a water-cooled condenser, exchanges heat with the radiator coolant circuit to heat the coolant. This heat is then transferred to the low-temperature radiator via an electric fan, where it is carried away by the heat to the outside air. After heat exchange, the refrigerant flows to the four-way valve, then back to the water pump to complete the cycle, passing through the water-cooled condenser to remove heat from the system. After passing through the water-cooled condenser, the refrigerant expands through an electronic expansion valve and enters the battery heat exchanger to evaporate and absorb heat. The battery heat exchanger then circulates the low-temperature coolant to the battery through the battery pack coolant circuit for cooling. After the battery heat exchanger, the refrigerant returns to the compressor for the next cycle.

[0028] The simplified circuit layout for refrigerant and coolant is as follows: Refrigerant: Compressor 108 → High-pressure temperature sensor 109 → Water-cooled condenser 104 → Liquid receiver dryer 105 → Electronic expansion valve 112 → Battery heat exchanger 111 → Low-pressure temperature sensor 110 → Return to compressor 108.

[0029] Battery coolant: First electronic water pump 113 → Battery heat exchanger 111 → Four-way valve 106 → Battery heater 107 → Battery pack 116 → Return to first electronic water pump 113.

[0030] Radiator coolant: Second electronic water pump 103 → Low temperature radiator 102 → Four-way valve 106 → Water-cooled condenser 104 → Return to second electronic water pump 103.

[0031] This application, by clearly defining the on / off states of the compressor, the first electronic water pump, and the second electronic water pump, as well as the off state of the battery heater, ensures that the system can concentrate energy for active cooling in compressor cooling mode, avoiding unnecessary energy loss and thus improving the system's energy efficiency ratio. The above technical solution, through precise control of the operating states of each component and clear heat exchange paths, provides stable, efficient, and reliable active cooling capabilities for the large-capacity battery packs of new energy commercial vehicles, thereby ensuring the vehicle's driving range and the long-term reliable operation of the battery system.

[0032] In one embodiment, such as Figure 2 As shown, this application further proposes that the circuit state in the battery heating mode is as follows: the compressor 108 and the second electronic water pump 103 are off, and the first electronic water pump 113 and the battery heater 107 are on; the battery coolant circuit circulates independently, the battery heater heats the circulating coolant, and the heated coolant flows through the battery pack to heat the battery.

[0033] In this mode, the compressor in the refrigerant circulation loop inside the unit does not start during winter, and the battery coolant loop circulates independently. A four-way valve isolates the battery coolant loop from the radiator coolant loop, preventing heat loss to the outside of the system or non-target areas and ensuring energy efficiency during battery heating. The battery water pump drives the coolant circulation flow through the battery heat exchanger and the four-way valve, then through the battery heater, where the coolant is heated. The heated coolant then returns to the battery water pump after heat exchange through the battery pack.

[0034] The simplified circuit for the battery coolant is as follows: First electronic water pump 113 → Battery heat exchanger 111 → Four-way valve 106 → Battery heater 107 → Battery pack 116 → Back to first electronic water pump 113.

[0035] Through the above technical solution, this system achieves a highly efficient and energy-saving battery heating process in battery heating mode by shutting down unnecessary energy-consuming components and concentrating energy on the battery heater and the first electronic water pump. The independent circulation design of the battery coolant circuit further reduces heat loss and ensures effective utilization of thermal energy. This optimization not only significantly reduces energy consumption during the heating process and improves the driving range of new energy commercial vehicles, but also ensures the normal operating performance and lifespan of the battery pack in low-temperature environments through precise control of the heating process, while maintaining the system's simplicity and reliability.

[0036] In one embodiment, such as Figure 3As shown, this application further proposes the following circuit state under natural cooling mode: compressor 108 and battery heater 107 are off, and first electronic water pump 113 and second electronic water pump 103 are on; coolant flows in the liquid cooling circulation path formed by the battery coolant circuit and the radiator coolant circuit connected in series, and dissipates heat to the outside air side through the low temperature radiator.

[0037] Specifically, in natural cooling mode, the compressor in the refrigerant circulation loop inside the system does not start in winter. The second electronic water pump drives the coolant into the low-temperature radiator, where it exchanges heat with the outside air through the electric fan. Then, it passes through the battery heater and battery pack in series through the four-way valve. After passing through the battery pack, the coolant carries away the battery heat. After being pressurized by the first electronic water pump, the coolant flows through the battery heat exchanger, the four-way valve, and the water-cooled condenser before returning to the second electronic water pump to complete the circulation.

[0038] The simplified circuit for the coolant is as follows: First electronic water pump 113 → Battery heat exchanger 111 → Four-way valve 106 → Water-cooled condenser 104 → Second electronic water pump 103 → Low-temperature radiator 101 → Four-way valve 106 → Battery heater 107 → Battery pack 116 → Back to first electronic water pump 113.

[0039] Through the above technical solution, in natural cooling mode, the system avoids unnecessary power consumption by shutting down the compressor and battery heater, reducing vehicle energy consumption and helping to improve the driving range of new energy commercial vehicles. Simultaneously, the activation of the first and second electronic water pumps ensures continuous flow of coolant in a single liquid-cooled circulation path formed by the series connection of the battery coolant circuit and the radiator coolant circuit, allowing the heat generated by the battery pack to be carried away by the coolant. Subsequently, this heat is directly dissipated to the outside air through the low-temperature radiator, fully utilizing the natural cooling capacity in low-temperature environments. This compressor-free cooling operation not only solves the problem of reduced driving range in low-temperature winter conditions, but more importantly, it can still provide effective cooling for the battery pack in ultra-low temperature environments, avoiding power reduction operation due to battery overheating, thereby ensuring the service life of key components such as the battery and motor. Overall, this solution achieves significant energy-saving effects and environmental adaptability while ensuring battery thermal management performance.

[0040] In one embodiment, this application further proposes to include a control module, which is configured to: adjust the rotation speed of the first electronic water pump according to the temperature difference between the inlet temperature and the outlet temperature of the battery pack, and control the flow rate of the coolant flowing through the battery pack. In the compressor cooling mode, the opening of the electronic expansion valve is adjusted according to the outlet superheat of the battery heat exchanger to control the refrigerant flow rate; the speed of the compressor is adjusted according to the difference between the target cooling temperature of the battery pack and the inlet water temperature; and the speed of the condenser fan associated with the water-cooled condenser is controlled according to the discharge pressure of the compressor. In the natural cooling mode, the speed of the electric fan associated with the low-temperature heat sink is controlled according to the difference between the target cooling temperature of the battery pack and the inlet water temperature. In the battery heating mode, the power of the battery heater is controlled according to the difference between the target heating temperature of the battery pack and the inlet water temperature.

[0041] The control module is the central processing unit responsible for the operation of the entire thermal management system. Its function is to receive sensor data from various parts of the system, execute preset control strategies, and output corresponding control commands to each actuator.

[0042] The control module adjusts the rotation speed of the first electronic water pump based on the temperature difference between the inlet and outlet temperatures of the battery pack, thereby controlling the flow rate of coolant through the battery pack. This temperature difference is a key indicator for measuring the heat generation efficiency of the battery pack and the efficiency of heat removal by the coolant. When the temperature difference increases, it indicates that the battery pack generates a large amount of heat or the cooling efficiency is insufficient. In this case, the control module will increase the rotation speed of the first electronic water pump to increase the coolant flow rate and enhance the cooling effect. Conversely, when the temperature difference decreases, the rotation speed will be reduced to reduce energy consumption.

[0043] In the compressor refrigeration mode, the control module adjusts the opening of the electronic expansion valve based on the outlet superheat of the battery heat exchanger to control the refrigerant flow. The outlet superheat of the battery heat exchanger is a crucial parameter for assessing the extent to which the refrigerant evaporates in the evaporator. Insufficient superheat may lead to wet compression, where liquid refrigerant enters the compressor, damaging it; excessive superheat indicates insufficient heat exchange in the evaporator, reducing refrigeration efficiency. By adjusting the opening of the electronic expansion valve, the refrigerant flow into the battery heat exchanger can be precisely controlled, thereby maintaining a suitable outlet superheat, ensuring sufficient refrigerant evaporation, improving refrigeration efficiency, and protecting the compressor.

[0044] Meanwhile, in the compressor cooling mode, the control module adjusts the compressor speed based on the difference between the target cooling temperature of the battery pack and the inlet water temperature. This difference directly reflects the cooling load required by the battery pack. When the difference is large, it indicates that the battery pack temperature is high and requires stronger cooling capacity. In this case, the control module will increase the compressor speed to increase the refrigerant circulation and thus enhance the cooling capacity. Conversely, when the difference is small, the speed will be reduced to decrease energy consumption.

[0045] In the natural cooling mode, the control module controls the speed of the electric fan associated with the low-temperature radiator based on the difference between the target cooling temperature of the battery pack and the inlet temperature. In natural cooling mode, the low-temperature radiator is the primary heat dissipation component. The difference between the target cooling temperature of the battery pack and the inlet temperature reflects the cooling requirements of the battery pack. When this difference is large, it indicates that the battery pack requires stronger heat dissipation. In this case, the control module increases the speed of the electric fan to increase the airflow through the low-temperature radiator, thereby enhancing the heat dissipation effect. Conversely, when the difference is small, the fan speed is reduced to save energy.

[0046] In the battery heating mode, the control module controls the power of the battery heater based on the difference between the target heating temperature of the battery pack and the inlet water temperature. This difference reflects the heating load required by the battery pack. When the difference is large, it indicates that the battery pack temperature is low and requires stronger heating capacity. In this case, the control module will increase the power of the battery heater to accelerate the heating speed. Conversely, when the difference is small, the heating power will be reduced to avoid overheating and energy waste.

[0047] Through the above technical solution, the control module can intelligently adjust various key components in the thermal management system using a preset control strategy, achieving precise control of the battery pack temperature. Specifically, this control strategy improves the operating efficiency, response speed, and energy utilization of the entire battery thermal management system through the coordinated adjustment of multiple parameters and modes, thereby optimizing the performance and lifespan of the battery pack.

[0048] In one embodiment, this application further proposes that the battery thermal management system with natural cooling also includes an integrated frame 117. The compressor 108, water-cooled condenser 104, liquid storage dryer 105, battery heat exchanger 111, battery heater 107, first electronic water pump 113, second electronic water pump 103, four-way valve 106, electronic expansion valve 112, and other equipment are all fixedly installed within the integrated frame 117 via brackets to form an integrated unit structure. Figure 4 As shown in the figure, only some of the devices are displayed.

[0049] The integrated frame is a prefabricated, structured support structure whose main function is to house and secure multiple independent system components. This integrated frame can be implemented in various forms. For example, it can be constructed from metal profiles (such as aluminum alloy or steel) welded or bolted together to form a skeleton structure, providing sufficient strength and rigidity to withstand the weight of the internal components and vibrations that may occur during system operation. Alternatively, the integrated frame can be integrally molded or modularly assembled from high-strength engineering plastics or composite materials to form a box or shell structure, providing necessary support while also achieving lightweight design and offering some protective functions. The integrated frame is the foundation for system integration, providing a unified and centralized installation platform for the previously dispersed components.

[0050] The bracket-mounted installation refers to the secure connection of each thermal management component to the integrated frame using specially designed connectors (i.e., brackets). Specifically, standard fasteners, such as bolts, nuts, and washers, can be used to secure the components to the brackets through their own mounting holes or pre-drilled mounting bases, and then the brackets are secured to the integrated frame. This fixed installation method aims to ensure that all components remain in a stable position during system operation, effectively preventing loosening, displacement, or potential damage to components caused by external factors such as vibration and impact during vehicle operation. It also facilitates subsequent disassembly and replacement of components.

[0051] The integrated unit structure refers to the integration of multiple originally dispersed functional components into a single unit with independent functions, compact structure, and easy handling and installation through the fixed installation of the integrated frame and the bracket.

[0052] Through the aforementioned technical solution, this application integrates the core components of the battery thermal management system into a unified framework, reducing the overall physical size of the system and the required installation space, effectively solving the problem of large system size caused by component dispersion. This highly integrated design optimizes the layout between components, reduces redundant piping and wiring harnesses, thereby lowering material costs. Simultaneously, the integrated unit structure simplifies the vehicle assembly process, reduces the complexity of on-site installation and labor costs, and improves production efficiency and product consistency. Furthermore, when the system requires maintenance or fault diagnosis, the concentration of all critical components in one area makes maintenance operations more convenient, improving system maintainability. This integrated design not only improves the system's reliability and durability but also provides a superior solution for the limited installation space of new energy commercial vehicles.

[0053] In one embodiment, this application further proposes that at least one side of the integrated frame is provided with a removable maintenance panel, the removal of which provides direct access to at least one device within the integrated frame.

[0054] Specifically, the removable service panel refers to a portion of the integrated frame housing or structure designed to allow for easy removal and reinstallation when needed. This panel can be implemented in several ways. For example, it can be secured to the side of the integrated frame with bolts or screws, allowing technicians to easily remove it during maintenance by simply unscrewing the fasteners with appropriate tools. This method is structurally robust and relatively simple to operate. Another implementation uses a snap-fit ​​or sliding mechanism, enabling the panel to be quickly removed with simple pressing, sliding, or unlocking operations, requiring little or no tools. This is particularly suitable for scenarios requiring frequent inspection or maintenance. The removal of the service panel provides direct access to at least one device within the integrated frame. This means that once the service panel is removed, a clear, unobstructed path is created, allowing maintenance personnel direct access to, inspection, diagnosis, repair, or replacement of specific equipment within the integrated frame.

[0055] Through the above technical solution, this application provides a detachable maintenance panel on at least one side of the integrated frame. This eliminates the need for extensive disassembly of the entire integrated frame during maintenance; simply removing the maintenance panel quickly exposes the internal equipment, simplifying the maintenance process and reducing its complexity and time. Furthermore, the direct access provided by the detachable maintenance panel ensures that maintenance personnel can directly access and operate the internal equipment, improving maintenance efficiency and convenience. This, in turn, reduces maintenance costs and vehicle downtime, and enhances system availability and reliability.

[0056] In one embodiment, this application further proposes a control method for a battery thermal management system with natural cooling, the method comprising: Determine whether the battery pack requires cooling or heating. If cooling is required, the ambient temperature is acquired. When the ambient temperature is greater than a first threshold, the battery thermal management system with natural cooling is controlled to enter the compressor cooling mode; when the ambient temperature is less than or equal to the first threshold, the battery thermal management system with natural cooling is controlled to enter the natural cooling mode. If heating is required, the battery thermal management system with natural cooling is controlled to enter battery heating mode.

[0057] Specifically, when determining whether the battery pack requires cooling or heating, the system compares the real-time temperature of the battery pack with a preset target temperature range. Ambient temperature can be directly obtained from an external vehicle temperature sensor. Once a cooling requirement is identified, the system further compares the obtained ambient temperature with a preset first threshold. If the ambient temperature is higher than the first threshold, it indicates that natural cooling may be insufficient to meet the battery pack's cooling needs. In this case, the control module sends a command to the mode switching device (e.g., a four-way valve) to switch to the flow path configuration corresponding to the compressor cooling mode and activates the compressor, first electric water pump, and second electric water pump, among other components, to provide robust active cooling. This first threshold can be a fixed value or a dynamically adjusted variable based on the battery pack's current temperature and power requirements. Conversely, if the ambient temperature is less than or equal to the first threshold, it indicates that the ambient temperature is low and ambient air can be effectively utilized for heat dissipation. In this case, the control module sends a command to the mode switching device (e.g., a four-way valve) to switch to the flow path configuration corresponding to the natural cooling mode to achieve energy-saving cooling. If a heating requirement is detected, the control module will send a command to the mode switching device (such as a four-way valve) to switch it to the flow path configuration corresponding to the battery heating mode, so as to achieve rapid heating of the battery pack.

[0058] Through the above technical solution, the control method realizes intelligent and adaptive control of the battery thermal management system with natural cooling. Through intelligent decision-making and mode switching, it optimizes the operating efficiency and reliability of the battery thermal management system, enabling it to adapt to various environmental conditions, thereby improving the performance and service life of the battery pack.

[0059] In one embodiment, this application proposes an automobile that includes the aforementioned battery thermal management system with natural cooling. The automobile can be any type of vehicle using a power battery, such as a commercial vehicle, electric truck, logistics vehicle, mining truck, etc.

[0060] It should be noted that the descriptions of each embodiment have their own emphasis. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0061] It is understood that those skilled in the art will clearly recognize that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0062] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0063] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application. Content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims

1. A battery thermal management system with natural cooling, characterized in that: include Battery coolant circuit, used for thermal management of the battery pack; The radiator coolant circuit is used for heat exchange with ambient air; A refrigerant circulation loop is used to provide active cooling when activated; The mode switching device has two operating states: In the first operating state, the battery coolant circuit is connected in parallel with the radiator coolant circuit, and the refrigerant circulation circuit is enabled or disabled to form a compressor cooling mode or a battery heating mode. In the second operating state, the battery coolant circuit and the radiator coolant circuit are connected in series to form a single liquid cooling circulation path, and the refrigerant circulation circuit is disabled to form a natural cooling mode.

2. The battery thermal management system with natural cooling according to claim 1, characterized in that: The battery coolant circuit includes a first electronic water pump, a battery heat exchanger, a four-way valve, a battery heater, and a battery pack connected in series via pipelines. The radiator coolant circuit includes a second electronic water pump, a low-temperature radiator, the four-way valve, and a water-cooled condenser connected in series via pipelines. The refrigerant circulation loop includes a compressor, a water-cooled condenser, a liquid receiver-drier, an electronic expansion valve, and a battery heat exchanger connected in series via pipelines. The mode switching device is the four-way valve.

3. The battery thermal management system with natural cooling according to claim 2, characterized in that, The circuit state under the compressor refrigeration mode is as follows: The compressor, the first electronic water pump, and the second electronic water pump are turned on, and the battery heater is turned off. The refrigerant circulation loop is activated, and the refrigerant exchanges heat with the flowing battery coolant in the battery heat exchanger. The coolant in the radiator coolant circuit exchanges heat with the refrigerant in the water-cooled condenser, and dissipates the heat to the outside air side in the low-temperature radiator.

4. The battery thermal management system with natural cooling according to claim 2, characterized in that, The circuit state under the battery heating mode is as follows: The compressor and the second electric water pump are turned off, while the first electric water pump and the battery heater are turned on. The battery coolant circuit circulates independently, and the battery heater heats the circulating coolant. The heated coolant then flows through the battery pack to heat the battery.

5. The battery thermal management system with natural cooling according to claim 2, characterized in that, The circuit state under the natural cooling mode is as follows: The compressor and the battery heater are turned off, while the first electronic water pump and the second electronic water pump are turned on. The coolant flows in the liquid cooling circulation path formed by the battery coolant circuit and the radiator coolant circuit connected in series, and dissipates heat to the outside air side through the low-temperature radiator.

6. The battery thermal management system with natural cooling according to claim 2, characterized in that, It also includes a control module, which is configured to: The speed of the first electronic water pump is adjusted according to the temperature difference between the inlet and outlet temperatures of the battery pack. In the compressor refrigeration mode, the opening degree of the electronic expansion valve is adjusted according to the outlet superheat of the battery heat exchanger; The compressor speed is adjusted according to the difference between the target cooling temperature of the battery pack and the inlet water temperature; In the natural cooling mode, the speed of the electric fan associated with the low-temperature heat sink is controlled according to the difference between the target cooling temperature of the battery pack and the inlet water temperature. In the battery heating mode, the power of the battery heater is controlled according to the difference between the target heating temperature of the battery pack and the inlet water temperature.

7. The battery thermal management system with natural cooling according to claim 2, characterized in that: It also includes an integrated frame, in which the compressor, water-cooled condenser, liquid storage dryer, battery heat exchanger, battery heater, first electronic water pump, second electronic water pump, four-way valve and electronic expansion valve are all fixedly installed in the integrated frame by brackets to form an integrated unit structure.

8. The battery thermal management system with natural cooling according to claim 7, characterized in that: At least one side of the integrated frame is provided with a removable maintenance panel, the removal of which provides direct access to at least one device within the integrated frame.

9. A control method for a battery thermal management system with natural cooling as described in any one of claims 1-8, characterized in that: Determine whether the battery pack requires cooling or heating. If cooling is required, the ambient temperature is acquired. When the ambient temperature is greater than a first threshold, the battery thermal management system with natural cooling is controlled to enter the compressor cooling mode; when the ambient temperature is less than or equal to the first threshold, the battery thermal management system with natural cooling is controlled to enter the natural cooling mode. If heating is required, the battery thermal management system with natural cooling is controlled to enter battery heating mode.

10. A car, characterized in that: Includes a battery thermal management system with natural cooling as described in any one of claims 1-8.

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