An electric vehicle and battery thermal management system

Abstract

The application discloses an electric vehicle and a battery thermal management system, and relates to the field of power battery heat dissipation technology. The battery thermal management system comprises a water pump, a heat exchanger, at least one power battery and at least one gas-liquid separation device which are connected in series through pipelines. The water pump is suitable for driving the cooling liquid in the pipeline to circulate. The heat exchanger is suitable for cooling the cooling liquid in the pipeline. The gas-liquid separation device is suitable for separating the gas in the cooling liquid. The gas-liquid separation device comprises a shell and a movable plug. The shell is provided with a separation cavity, a water inlet and a water outlet which are connected with the separation cavity, and an exhaust hole which is connected with the top of the separation cavity. The movable plug is at least partially located in the separation cavity and is configured to float in the cooling liquid in the separation cavity and seal against the exhaust hole. The movable plug is suitable for opening the exhaust hole when the liquid level of the cooling liquid in the separation cavity drops to a preset position. The gas in the cooling circulation pipeline can be efficiently separated and automatically discharged, and the cooling effect is significantly improved.

Description

Technical Field

[0001] This utility model relates to the field of power battery heat dissipation technology, and more specifically, to an electric vehicle and battery thermal management system. Background Technology

[0002] Commercial vehicle power batteries continuously generate heat during operation. If this heat cannot be dissipated in time, the battery temperature will rise, affecting the battery's performance stability and lifespan, and potentially even posing safety risks. Therefore, the commercial vehicle sector requires specialized cooling systems to control the battery temperature, ensuring it remains within a suitable operating temperature range to meet the vehicle's normal operating needs.

[0003] Currently, commercial vehicle power batteries typically employ an integrated air conditioning cooling system for cooling. This system generally consists of an integrated air conditioning cooling module, a water pump, an expansion tank, piping, and the power battery. Its working principle is as follows: after the coolant is cooled in the integrated air conditioning cooling module, it circulates through the piping to the internal cooling structure of the power battery under the drive of the water pump, exchanging heat with the battery cells and thus carrying away the heat generated by the cells, achieving cooling of the power battery.

[0004] However, existing integrated cooling systems for commercial vehicle power batteries have significant drawbacks in practical applications. Unremoved air can easily remain inside the coolant filling lines, interfering with normal coolant circulation and reducing system efficiency. Simultaneously, during coolant circulation, dissolved gases in the water are gradually released, forming small bubbles. These bubbles, carried by the coolant to the internal cooling structure of the power battery, affect heat exchange, thus reducing the cooling efficiency of the battery cells. Utility Model Content

[0005] This invention provides a thermal management system for electric vehicles and batteries, which aims to improve at least one of the aforementioned technical problems.

[0006] To solve the above-mentioned technical problems, this utility model provides a battery thermal management system, which includes: a water pump, a heat exchanger, at least one power battery and at least one gas-liquid separation device connected in series through pipelines; The water pump is adapted to circulate the coolant in the pipeline; The heat exchanger is adapted to cool the coolant in the pipeline; The gas-liquid separation device is suitable for separating gas from coolant; The gas-liquid separator has a housing and a movable plug; the housing is provided with a separation chamber, an inlet and an outlet connecting the separation chamber, and an exhaust port connecting the top of the separation chamber; The movable plug is at least partially located in the separation chamber and is configured to float in the coolant in the separation chamber and seal against the vent hole; the movable plug is adapted to open the vent hole when the coolant level in the separation chamber drops to a preset position.

[0007] As a further optimization, the separation chamber is provided with an exhaust channel communicating with the exhaust port; the movable plug includes a movable part movably disposed in the exhaust channel and a floating part located in the separation chamber; the cross-sectional area of ​​the floating part gradually decreases from top to bottom. Preferably, the floating part is provided with a cavity for increasing buoyancy.

[0008] As a further optimization, the top of the floating part is arc-shaped; the bottom is conical; and the angle A of the cone is 80 to 100 degrees.

[0009] As a further optimization, the upper part of the separation chamber is hemispherical; the lower part of the separation chamber is cylindrical; the inlet and the outlet are tangent to the sidewalls of the cylindrical portion of the separation chamber, and the height of the inlet is higher than that of the outlet. Preferably, the arc shape of the top of the floating part is the same as the hemispherical arc shape of the upper part of the separation chamber; As a further optimization, we define: the height of the cylindrical part of the separation chamber is B, the diameter of the cylindrical part of the separation chamber is C, the height difference between the inlet and the outlet is D, and the diameter of the inlet and the outlet are the same as Φ; then C > 4Φ; D > B / 2.

[0010] As a further optimization, the heat exchanger is connected to the water pump; the water pump is connected to the power battery; the power battery is connected to the heat exchanger; the gas-liquid separation device is connected between the heat exchanger and the water pump, and / or the gas-liquid separation device is connected between the water pump and the power battery, and / or the gas-liquid separation device is connected between the power battery and the heat exchanger.

[0011] As a further optimization, the heat exchanger is an air conditioning plate heat exchanger, an air conditioning tube heat exchanger, or an air conditioning brazed plate heat exchanger.

[0012] As a further optimization, there are multiple power batteries; the multiple power batteries are connected by a series and parallel connection in the water circuit.

[0013] This application also provides an electric vehicle that includes the battery thermal management system described in any paragraph of the first aspect.

[0014] By adopting the above technical solution, the present invention can achieve the following technical effects: This utility model's battery thermal management system is equipped with a gas-liquid separation device, which can efficiently separate and automatically discharge gas from the cooling circulation pipeline, significantly improving the cooling effect. This design effectively reduces the interference of residual air bubbles in the system on the cooling effect, thereby enhancing the heat dissipation performance of the power battery, ensuring that the battery operates within the optimal temperature range, and reducing system operating energy consumption.

[0015] The structural design of the gas-liquid separator, especially the combination of the movable plug and the specially shaped separation chamber, achieves reliable gas separation and sealing. Its flexibility for multi-position installation facilitates its placement and maintenance on commercial vehicles. The entire system does not rely on complex vacuum filling equipment, simplifying the operation process, improving reliability, and reducing costs. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the specific embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the piping connection of the battery thermal management system.

[0018] Figure 2 This is an isometric view of the bubble separation component.

[0019] Figure 3 This is a partial cross-sectional view of the bubble separation component.

[0020] Figure 4 This is a first-view half-section view of the bubble separation component.

[0021] Figure 5 This is a half-section view of the bubble separation component from a second perspective.

[0022] The markings in the diagram are: 1-Gas-liquid separation device, 2-Outer shell, 3-Separation chamber, 4-Inlet, 5-Floating part, 6-Modible plug, 7-Modible part, 8-Exhaust hole, 9-Exhaust channel, 10-Outlet, 11-Water pump. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0024] Example 1: In the prior art, commercial vehicle power battery cooling systems generally adopt a circulation structure consisting of an integrated air conditioning cooling module, a water pump 11, and an expansion tank. Such systems suffer from difficulties in venting the pipelines during coolant filling, resulting in residual air bubbles that reduce circulation efficiency. Simultaneously, tiny air bubbles adhering to the cell surface affect heat exchange. Traditional venting methods in the production process require multiple manual interventions, are time-consuming, and rely on specialized equipment, severely impacting assembly efficiency.

[0025] To address the aforementioned problems, the inventors discovered that the root cause of gas residue in the pipeline lies in the lack of an effective automatic separation mechanism. Through observation of the cooling system's operation, it was found that gas tends to accumulate at specific locations during coolant circulation. Based on fluid mechanics principles, a separation device with a buoyancy control structure was proposed to be installed in the circulation loop. This device triggers the venting action through changes in liquid level, achieving a dynamic balance between automatic gas separation and a sealed state.

[0026] Therefore, by Figures 1 to 5 As shown, this utility model embodiment provides a battery thermal management system, which includes: a water pump 11, a heat exchanger, at least one power battery and at least one gas-liquid separation device 1 connected in series through pipelines; wherein, each component is connected in series through pipelines to form a closed loop.

[0027] The water pump 11 is adapted to circulate the coolant in the pipeline; The heat exchanger is suitable for cooling the coolant in the pipeline; in this embodiment, the heat exchanger is an air conditioning plate heat exchanger, an air conditioning tube heat exchanger, or an air conditioning brazed plate heat exchanger. Specifically, the heat exchanger is existing technology and this invention does not specifically limit it.

[0028] The gas-liquid separation device 1 is suitable for separating gas from coolant; The gas-liquid separator 1 has a housing 2 and a movable plug 6; the housing 2 is provided with a separation chamber 3, an inlet 4 and an outlet 10 connecting the separation chamber 3, and an exhaust hole 8 connecting the top of the separation chamber 3; Separation chamber 3 refers to a container with a tangential water inlet structure, which can be implemented by connecting a cylindrical cavity to a tangential pipe, promoting gas-liquid stratification through the swirling effect. Movable plug 6 refers to a sealing component with buoyancy adjustment function, which can be implemented by a conical structure with an internal cavity. The cavity volume and material density work together to create a predetermined buoyancy, ensuring displacement when the liquid level changes.

[0029] The movable plug 6 is at least partially located in the separation chamber 3 and is configured to float in the coolant within the separation chamber 3 and seal against the vent hole 8. The movable plug 6 is adapted to open the vent hole 8 when the coolant level in the separation chamber 3 drops to a preset position. Specifically, when the liquid level reaches a preset height, buoyancy pushes the plug to seal the vent hole 8; when gas accumulates in the upper part of the separation chamber 3, causing the liquid level to drop, the plug disengages from the vent hole 8 to release the gas.

[0030] Specifically, the coolant, driven by the water pump 11, flows through the heat exchanger to cool down before entering the power battery. After absorbing heat, it returns to the heat exchanger to complete the cycle. The gas-liquid separation device 1 is arranged in the circulation loop. The gas-containing coolant enters the separation chamber 3 from the tangential inlet 4, forming a swirling flow. Under the action of centrifugal force, the gas accumulates at the top of the chamber. When the liquid level rises, the movable plug 6 floats up and seals the vent 8; the accumulation of gas causes the liquid level to drop. When it drops to a certain position, the plug falls due to gravity, opening the vent passage 9 to release the gas. This process requires no external control and automatically maintains the balance between the system's airtightness and venting function.

[0031] Compared to existing technologies, current systems rely on passive venting from an expansion tank, where gas can easily stagnate at pipe bends. This solution utilizes an active gas-liquid separation device 1 to achieve directional bubble aggregation and automatic venting, eliminating manual intervention. Traditional normally open vent holes 8 suffer from coolant evaporation losses; this design achieves dynamic sealing through buoyancy control, ensuring continuous venting while preventing liquid leakage.

[0032] Through the above technical solution, this application achieves rapid automatic venting of the cooling system, shortening the refueling operation time. It effectively reduces the air bubble content in the circulation pipeline, avoiding localized overheating caused by air bubbles adhering to the battery cells. The integrated design of the separation device and pipeline reduces maintenance complexity and is suitable for space-constrained commercial vehicle chassis layouts.

[0033] Based on the above embodiments, in an optional embodiment of the present invention, such as Figure 3 As shown, the separation chamber 3 is provided with an exhaust channel 9 communicating with the exhaust port 8; the movable plug 6 includes a movable part 7 movably disposed in the exhaust channel 9, and a floating part 5 located in the separation chamber 3; the cross-sectional area of ​​the floating part 5 gradually decreases from top to bottom. Preferably, the floating part 5 is provided with a cavity for increasing buoyancy.

[0034] The exhaust channel 9 refers to a tubular structure located at the top of the separation chamber 3 and communicating with the exhaust port 8. It can be implemented using a vertically or inclined cylindrical pipe, used to guide the gas out in a directional manner. The movable part 7 refers to a columnar component that slides against the inner wall of the exhaust channel 9. It can be implemented using a metal rod wrapped with a PTFE sealing ring, used to control the opening and closing of the exhaust channel 9. The floating part 5 refers to a buoyancy structure with a gradually changing cross-section and an internal cavity. It can be implemented using a conical shell with a closed air cavity inside, increasing the buoyancy response speed by increasing the drainage volume.

[0035] When coolant enters the separation chamber 3, the liquid level gradually rises, pushing the float 5 to the surface. The buoyancy generated by the cavity structure causes the movable part 7 to move upwards until the exhaust channel 9 is sealed. At this point, gas accumulates at the top of the separation chamber 3 under centrifugal force. When the accumulated gas causes the liquid level to drop to a preset position, the float 5, due to gravity, causes the movable part 7 to move downwards, opening the exhaust channel 9, and the accumulated gas is discharged along the exhaust channel 9. The float 5 adopts a gradually decreasing cross-section design, which reduces liquid flow resistance. At the same time, the cavity structure increases the buoyancy output per unit volume, ensuring that the movable part 7 can quickly respond to changes in liquid level.

[0036] Based on the above embodiments, in an optional embodiment of the present invention, such as Figures 3 to 5 As shown, the top of the floating part 5 is arc-shaped; the bottom is conical; and the angle A of the cone is 80 to 100 degrees.

[0037] An arc-shaped top refers to the continuously curved surface of the floating body's upper surface. A conical bottom refers to the cone-shaped structure formed on the lower surface of the floating body. A cone angle of 80 to 100 degrees refers to the range of angles formed by the generatrices on both sides of the cone; this angle range balances structural strength and displacement sensitivity.

[0038] Based on the above embodiments, in an optional embodiment of the present invention, such as Figures 3 to 5 As shown, the upper part of the separation chamber 3 is hemispherical; the lower part of the separation chamber 3 is cylindrical; the inlet 4 and the outlet 10 are tangent to the sidewalls of the cylindrical portion of the separation chamber 3, and the height of the inlet 4 is higher than that of the outlet 10. Preferably, the arc shape of the top of the floating part 5 is the same as the hemispherical arc shape of the upper part of the separation chamber 3; The hemispherical upper part of the separation chamber 3 refers to the top being a semi-circular curved surface structure, the curvature of which matches the shape of the top of the floating part 5, used to guide bubbles to gather at the top. The cylindrical lower part refers to the bottom being a cylindrical structure of equal diameter, which can be achieved through machining or casting processes, used to maintain the stability of fluid flow.

[0039] The tangentially aligned inlet 4 and outlet 10 refer to the pipe inlet being tangentially aligned with the outer circumference of the cylindrical section, used to create a swirling flow within the separation chamber 3. The inlet 4 being higher than the outlet 10 means that the centerline of the inlet pipe is higher than the outlet pipe, used to extend the coolant residence time.

[0040] When the coolant enters the cylindrical separation chamber 3 tangentially, it creates a swirling flow. Centrifugal force causes the bubbles to move towards the center of the chamber. The hemispherical top mates with the arc surface of the floating part 5, causing the rising bubbles to gather at the top and form an air chamber. As the liquid level drops, the floating part 5 moves downwards accordingly, and the top vent 8 opens to release the gas.

[0041] The high-position arrangement of inlet 4 allows the liquid to slowly sink under gravity, giving the bubbles ample time to rise, while the low-position arrangement of outlet 10 avoids disturbing the top air chamber. The centrifugal force generated by the swirling flow accelerates gas-liquid stratification, and the hemispherical structure reduces turbulence interference, achieving highly efficient gas separation.

[0042] Based on the above embodiments, in an optional embodiment of the present invention, such as Figures 4 to 5 As shown, the following definitions apply: the height of the cylindrical portion of the separation chamber 3 is B; the diameter of the cylindrical portion of the separation chamber 3 is C; the height difference between the inlet 4 and the outlet 10 is D; and the diameters of the inlet 4 and the outlet 10 are the same, denoted as Φ. Therefore, C > 4Φ; D > B / 2. Preferably, Φ = 20mm, C = 90mm, B = 150mm, and D = 120mm.

[0043] After the coolant enters the separation chamber 3, the flow rate decreases due to the significantly larger diameter of the chamber compared to the pipe diameter, allowing the bubbles sufficient time to rise. The inlet 4 is located in the upper region of the chamber, and the outlet 10 is located in the lower region. The pressure difference created by the height difference between the two drives the fluid downwards, preventing bubbles from flowing back with the outlet water. The upper space of the chamber provides a buffer zone for bubble aggregation, while the lower region maintains a stable liquid level. The movable plug 6 automatically opens and closes the vent 8 according to changes in the liquid level, achieving continuous gas-liquid separation.

[0044] The existing commercial vehicle cooling system does not optimize the structural parameters of the gas-liquid separator 1, resulting in insufficient coolant residence time and incomplete separation of air bubbles before they enter the circulation system. This solution extends the gas-liquid contact time by limiting the ratio of the cavity diameter to the pipe diameter, and simultaneously establishes directional flow by controlling the height difference between the inlet and outlet 10, effectively preventing the separated gas from re-entering the circulation pipeline.

[0045] Based on the above embodiments, in an optional embodiment of the present invention, such as Figure 1As shown, the heat exchanger is connected to the water pump 11; the water pump 11 is connected to the power battery; the power battery is connected to the heat exchanger; the gas-liquid separation device 1 is connected between the heat exchanger and the water pump 11, and / or the gas-liquid separation device 1 is connected between the water pump 11 and the power battery, and / or the gas-liquid separation device 1 is connected between the power battery and the heat exchanger.

[0046] Specifically, the gas-liquid separator 1 can be provided as a single unit or in multiple units. Preferably, only one gas-liquid separator 1 is provided and installed between the power battery and the heat exchanger. In an optional embodiment, multiple gas-liquid separators 1 can be connected in series or in parallel to improve the gas-liquid separation effect.

[0047] The connection position of the gas-liquid separator 1 refers to the installation of the gas-liquid separator 1 at least one of the three key nodes in the coolant circulation path. Specifically, it can be achieved by flange connection or clamp connection. This arrangement can cover different sections after the coolant flows through the heat exchanger for cooling, after it flows through the water pump 11 for pressurization, and after it flows through the power battery for heat absorption.

[0048] Based on the above embodiments, in an optional embodiment of the present invention, such as Figure 1 As shown, there are multiple power batteries; these power batteries are connected in series and parallel via a water circuit. Preferably, the inlet and outlet ports 10 of the power batteries are connected using water pipes with an inner diameter of 16 mm. The inlet and outlet ports 10 of the water pump 11 and the gas-liquid separator 1 are connected using water pipes with an inner diameter of 25 mm. The 16 mm and 25 mm water pipes are connected via an adapter.

[0049] The series-parallel water circuit connection method refers to the partial series connection and partial parallel connection of water circuits between multiple power batteries. Specifically, it can be achieved by using a combination of a three-way connector and a water distributor. This method can balance the coolant flow distribution of different power battery units.

[0050] Example 2: This application also provides an electric vehicle that includes the battery thermal management system described in any paragraph of Example 1.

[0051] Obviously, the above detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to describe preferred embodiments, not all embodiments, and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Based on the embodiments of the present invention, any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art to all other embodiments obtained without inventive effort are within the scope of protection of the present invention.

Claims

1. A battery thermal management system, characterized in that, It includes: a water pump (11) connected in series via pipelines, a heat exchanger, at least one power battery and at least one gas-liquid separation device (1). The water pump (11) is adapted to circulate the coolant in the pipeline; The heat exchanger is adapted to cool the coolant in the pipeline; The gas-liquid separation device (1) is suitable for separating gas from coolant; The gas-liquid separator (1) has a housing (2) and a movable plug (6); the housing (2) is provided with a separation chamber (3), an inlet (4) and an outlet (10) connecting the separation chamber (3), and an exhaust hole (8) connecting the top of the separation chamber (3); The movable plug (6) is at least partially located in the separation chamber (3) and is configured to float in the coolant in the separation chamber (3) and seal against the vent hole (8); the movable plug (6) is adapted to open the vent hole (8) when the coolant level in the separation chamber (3) drops to a preset position.

2. The battery thermal management system according to claim 1, characterized in that, The separation chamber (3) is provided with an exhaust channel (9) that connects to the exhaust port (8); The movable plug (6) includes a movable part (7) that is movably disposed in the exhaust channel (9) and a floating part (5) located in the separation chamber (3); the cross-sectional area of ​​the floating part (5) gradually decreases from top to bottom.

3. A battery thermal management system according to claim 2, characterized in that, The top of the floating part (5) is arc-shaped; the bottom is conical; and the angle A of the cone is 80 to 100 degrees.

4. A battery thermal management system according to claim 3, characterized in that, The upper part of the separation cavity (3) is hemispherical; the lower part of the separation cavity (3) is cylindrical. The inlet (4) and the outlet (10) are respectively tangent to the side wall of the cylindrical part of the separation chamber (3), and the height of the inlet (4) is higher than that of the outlet (10).

5. A battery thermal management system according to claim 4, characterized in that, The top arc of the floating part (5) is the same as the hemispherical arc of the upper part of the separation cavity (3); Definition: The height of the cylindrical part of the separation chamber (3) is B, the diameter of the cylindrical part of the separation chamber (3) is C, the height difference between the inlet (4) and the outlet (10) is D, and the diameter of the inlet (4) and the outlet (10) are the same as Φ; then C > 4Φ; D > B / 2.

6. A battery thermal management system according to claim 2, characterized in that, The floating part (5) is provided with a cavity to increase buoyancy.

7. A battery thermal management system according to any one of claims 1 to 6, characterized in that, The heat exchanger is connected to the water pump (11); the water pump (11) is connected to the power battery; the power battery is connected to the heat exchanger; The gas-liquid separation device (1) is connected between the heat exchanger and the water pump (11), and / or the gas-liquid separation device (1) is connected between the water pump (11) and the power battery, and / or the gas-liquid separation device (1) is connected between the power battery and the heat exchanger.

8. A battery thermal management system according to any one of claims 1 to 6, characterized in that, The heat exchanger is an air conditioning plate heat exchanger, an air conditioning tube heat exchanger, or an air conditioning brazed plate heat exchanger.

9. A battery thermal management system according to any one of claims 1 to 6, characterized in that, There are multiple power batteries; the multiple power batteries are connected by a series and parallel connection in the water circuit.

10. An electric vehicle, characterized in that, It includes a battery thermal management system as described in any one of claims 1 to 9.

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