Novel heating system applied to power battery

Abstract

The invention relates to the technical field of power batteries, in particular to a novel heating system applied to a power battery. Comprising a shell and a shell cover. The shell cover is fixedly connected with the shell; a liquid cooling plate is mounted at the bottom of the shell; the temperature equalizing pipe is attached to the surface of the battery cell, and in winter, the heater firstly heats the cooling liquid conveyed into the temperature equalizing pipe by the micro water pump, so that when the heated cooling liquid flows through the temperature equalizing pipe, the hot cooling liquid can transfer heat to the battery cell through the pipe wall of the temperature equalizing pipe, and the battery cell is heated by the temperature equalizing pipe; in summer, cooling liquid is directly conveyed to the uniform-temperature pipe by controlling the micro water pump, heat generated by the battery cell is rapidly taken away by utilizing the heat exchange effect of the pipe wall, accurate cooling is realized, the risk of thermal runaway caused by overheating of the battery is effectively avoided, and the service life of the battery cell is prolonged. And reliable guarantee is provided for safe and stable operation of the power battery.

Description

Technical Field

[0001] This invention relates to the field of power battery technology, specifically a novel heating system for power batteries. Background Technology

[0002] With the rapid development of the new energy industry, the transportation market, including passenger cars, commercial vehicles, and two-wheeled vehicles, has undergone tremendous changes. In the past, lead-acid batteries were commonly used in low-speed household two-wheeled vehicles, but now lithium batteries have been replaced by series batteries. The commonly used 48V series battery packs have been replaced by series-parallel lithium batteries. From basic display configurations to intelligent configurations such as infrared, Bluetooth, and WiFi modules, these intelligent configurations have driven the rapid rise of the intelligent two-wheeled vehicle market. Technological iteration has not only significantly improved the user's travel experience but also accelerated the overall upgrading of the industry.

[0003] However, the new energy battery industry still faces many technical bottlenecks, among which the range reduction problem in low-temperature environments is particularly prominent and has become a consensus pain point in the industry. Taking mainstream 48V electric vehicles as an example, the range can reach about 30 kilometers on a full charge in summer, but in low-temperature winter environments, the range often drops sharply to 20 kilometers, and in extreme cases, it can even be reduced by half. This seriously affects the user's daily experience. This problem not only restricts the popularization of new energy vehicles, but also causes a significant decrease in battery working efficiency and energy conversion efficiency, directly leading to the degradation of battery charging and discharging performance, and thus accelerating the battery aging process. This chain reaction not only shortens the lifespan of the battery itself, but also poses a serious challenge to the overall lifespan of the vehicle. In view of this, in order to overcome the above-mentioned technical problems, the present invention proposes a novel heating system for power batteries, which solves the above-mentioned technical problems. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention proposes a novel heating system for power batteries. This invention involves attaching a heat spreader to the surface of the battery cell. In winter, a heater first heats the coolant delivered to the heat spreader by a micro-pump. As the heated coolant flows through the heat spreader, the heat is transferred to the battery cell via the tube wall, thus heating the cell and reducing electrolyte viscosity. This improves battery cell discharge efficiency and effectively alleviates the problem of reduced range in winter. In summer, the micro-pump directly delivers coolant to the heat spreader, utilizing the heat exchange effect of the tube wall to quickly remove the heat generated by the battery cell, achieving precise cooling and effectively avoiding the risk of thermal runaway due to overheating. This provides a reliable guarantee for the safe and stable operation of the power battery.

[0005] The technical solution adopted by this invention to solve its technical problem is as follows: A novel heating system for power batteries, comprising a housing and a cover; the cover is fixedly connected to the housing; a liquid cooling plate is installed at the bottom of the housing; a battery cell assembly is installed inside the cover; the battery cell assembly is located between the liquid cooling plate and the cover; the battery cell assembly includes a battery cell and a heat spreader; multiple sets of battery cells are arranged; the heat spreader is installed between two adjacent sets of battery cells; the heat spreader is corrugated; the contoured surface of the heat spreader is in contact with the surface of the battery cell; a strip groove is formed on the inner wall of the housing; both ends of the heat spreader are slidably connected within the strip groove; a connector is installed at both ends of the heat spreader; a water inlet pipe is provided on one side of the housing; the water inlet pipe is connected to the connector at one end of the heat spreader; a heater is connected to the end of the water inlet pipe away from the heat spreader; a miniature water pump is installed on the side wall of the housing; one end of the miniature water pump is connected to the outlet of the liquid cooling plate, and the other end is connected to the heater; the connector at the other end of the heat spreader is connected to the inlet of the liquid cooling plate.

[0006] Furthermore, the heater includes a heating tube; the surface of the heating tube is covered with a heating film; the heating film has two layers; a heating resistance wire is wrapped between the two layers of the heating film; the two ends of the heating resistance wire are connected to the positive and negative poles of the heating film; the heating film is connected to a power source via a wiring harness.

[0007] Furthermore, a temperature control switch connected to the heating film is attached to the surface of the heating tube; the heating tube is made of aluminum alloy material.

[0008] Furthermore, a liquid storage chamber is provided inside the housing; the water outlet of the liquid cooling plate is connected to the liquid storage chamber; the liquid storage chamber is connected to a micro water pump; and the water outlet of the micro water pump is connected to a heater via a hose.

[0009] Furthermore, a partition is fixedly installed inside the liquid storage chamber; the partition divides the liquid storage chamber into a first liquid storage chamber and a second liquid storage chamber; the micro water pump is connected to the second liquid storage chamber; the water outlet of the liquid cooling plate is connected to the first liquid storage chamber; a connecting hole is opened on the surface of the partition; a solenoid valve is installed in the connecting hole; a traction unit is installed in the second liquid storage chamber; the traction unit is used to pull the temperature equalization tube to slide within the shell.

[0010] Furthermore, the traction unit includes a sealing plate and a steel wire rope; the sealing plate is slidably and sealingly connected to the second liquid storage chamber; one end of the steel wire rope is fixedly connected to the sealing plate, and the other end is connected to the temperature equalization pipe.

[0011] Furthermore, two sets of hanging ears are fixedly connected to the side of the heat-equalizing tube near the shell cover; a connecting spring connected to the hanging ears is fixedly connected to the side of the shell cover near the heat-equalizing tube; and the end of the steel wire rope away from the sealing plate is connected to the hanging ears.

[0012] Furthermore, the surface of the heat exchanger tube is coated with a graphene coating.

[0013] Furthermore, the surface of the temperature distribution tube 132 is coated with an epoxy resin insulating coating; the thickness of the epoxy resin insulating coating is set to 0.2 mm.

[0014] Furthermore, the surface of the temperature equalization tube has two through grooves; the connecting nozzle is installed in the through groove; the connecting nozzle is rotatably and sealingly connected to the inner wall of the through groove; the connecting nozzle includes a round cap and a connecting tube; the round cap and the connecting tube are distributed on both sides of the through groove; the round cap is threadedly connected to the connecting tube; and a round hole is formed on the surface of the connecting tube.

[0015] The beneficial effects of this invention are as follows: This invention involves attaching a heat spreader to the surface of the battery cell. In winter, a heater first heats the coolant delivered to the heat spreader by a micro-pump. As the heated coolant flows through the heat spreader, the heat is transferred to the battery cell through the tube wall, thus heating the battery cell. This reduces the viscosity of the electrolyte, improves the discharge efficiency of the battery cell, and effectively alleviates the problem of range reduction in winter. In summer, the micro-pump directly delivers coolant to the heat spreader, utilizing the heat exchange effect of the tube wall to quickly remove the heat generated by the battery cell, achieving precise cooling and effectively avoiding the risk of thermal runaway due to overheating. This provides a reliable guarantee for the safe and stable operation of the power battery.

[0016] This invention incorporates a traction unit that allows the heat exchanger tube to slide up and down within a strip groove. This ensures that the effective contact area of ​​the sliding heat exchanger tube covers the entire height range of the battery cell, guaranteeing sufficient heat exchange and achieving comprehensive cooling of the battery cell. Simultaneously, during the sliding process, the relative movement between the heat exchanger tube and the battery cell surface increases, thereby increasing the contact area between them, reducing contact thermal resistance, improving the heat transfer rate, and further enhancing the cooling effect on the battery cell. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a partial cross-sectional view of the present invention; Figure 2 This is a partial cross-sectional view of the housing used in this invention; Figure 3 This is a bottom view of the housing used in this invention; Figure 4 This is a three-dimensional view of the heat exchanger used in this invention; Figure 5 yes Figure 4 Enlarged view of point A in the middle; Figure 6 yes Figure 4 Enlarged view of point B in the middle; In the diagram: 1. Shell; 11. Shell cover; 111. Connecting spring; 12. Liquid cooling plate; 13. Battery cell assembly; 131. Battery cell; 132. Heat distribution tube; 133. Water inlet pipe; 134. Through groove; 135. Hanging ear; 14. Strip groove; 15. Connecting nozzle; 151. Round cover; 152. Connecting pipe; 153. Round hole; 16. Liquid storage chamber; 161. Partition plate; 162. Liquid storage chamber No. 1; 163. Liquid storage chamber No. 2; 164. Connecting hole; 165. Solenoid valve; 17. Sealing plate; 171. Steel wire rope; 2. Heater; 21. Heating tube; 22. Heating film; 23. Heating resistance wire; 24. Temperature control switch; 3. Miniature water pump; 31. Hose. Detailed Implementation

[0019] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0020] like Figures 1 to 6 As shown, the present invention includes the following embodiments: Example 1: A novel heating system for power batteries includes a housing 1 and a cover 11; the cover 11 is fixedly connected to the housing 1; a liquid cooling plate 12 is installed at the bottom of the housing 1; a battery cell assembly 13 is installed inside the cover 11; the battery cell assembly 13 is located between the liquid cooling plate 12 and the cover 11; the battery cell assembly 13 includes battery cells 131 and a heat spreader 132; multiple sets of battery cells 131 are arranged; the heat spreader 132 is installed between two adjacent sets of battery cells 131; the heat spreader 132 is wavy; the contoured surface of the heat spreader 132 is in contact with the surface of the battery cell 131; the housing 1... The inner wall is provided with a strip groove 14; both ends of the temperature equalization tube 132 are slidably connected in the strip groove 14; both ends of the temperature equalization tube 132 are equipped with a connecting nozzle 15; a water inlet pipe 133 is provided on one side of the housing 1; the water inlet pipe 133 is connected to the connecting nozzle 15 at one end of the temperature equalization tube 132; a heater 2 is connected to the end of the water inlet pipe 133 away from the temperature equalization tube 132; a micro water pump 3 is installed on the side wall of the housing 1; one end of the micro water pump 3 is connected to the water outlet of the liquid cooling plate 12, and the other end is connected to the heater 2; the connecting nozzle 15 at the other end of the temperature equalization tube 132 is connected to the water inlet of the liquid cooling plate 12.

[0021] In this embodiment, the heater 2 includes a heating tube 21; the surface of the heating tube 21 is covered with a heating film 22; the heating film 22 is provided with two layers; a heating resistance wire 23 is wrapped between the two layers of the heating film 22; the two ends of the heating resistance wire 23 are connected to the positive and negative poles of the heating film 22; the heating film 22 is connected to a power source through a wire harness.

[0022] In this embodiment, a temperature control switch 24 connected to the heating film 22 is attached to the surface of the heating tube 21; the heating tube 21 is made of aluminum alloy material.

[0023] When in operation, existing electric vehicles (taking mainstream 48V electric vehicles as an example) can achieve a range of about 30 kilometers when fully charged in summer. However, in the low-temperature environment of winter, the range often drops sharply to 20 kilometers, and in extreme cases, it can even be reduced by half, which seriously affects the user's daily experience. The reason for this problem is that the low temperature causes the electrolyte viscosity to increase, the internal resistance of the 131 cell to increase, and the migration speed of lithium ions between the positive and negative electrode materials to slow down. As a result, more electrical energy is converted into heat energy loss during the transmission process, which greatly improves the battery discharge efficiency.

[0024] To address this issue, the present invention attaches a heat spreader 132 to the surface of the battery cell 131. In winter, the heater 2 first heats the coolant delivered to the heat spreader 132 by the micro water pump 3. As the heated coolant flows through the heat spreader 132, the hot coolant can transfer heat to the battery cell 131 through the pipe wall of the heat spreader 132, thereby heating the battery cell 131. This reduces the viscosity of the electrolyte, improves the discharge efficiency of the battery cell 131, and effectively alleviates the problem of range reduction in winter. In summer, the micro water pump 3 is controlled to directly deliver coolant to the heat spreader 132. Utilizing the heat exchange effect of the pipe wall, the heat generated by the battery cell 131 is quickly removed, achieving precise cooling and effectively avoiding the risk of thermal runaway caused by overheating of the battery. This provides a reliable guarantee for the safe and stable operation of the power battery.

[0025] When driving in winter, if the ambient temperature is -10℃, the electrolyte in cell 131 has a high viscosity. In this case, the operator needs to send a command to heater 2 via the vehicle's controller before driving. Since the positive and negative terminals of heater 2 are connected to the power supply via wiring harnesses, the heating resistance wire 23 of heater 2 is energized, causing it to heat up. Because the heating resistance wire 23 is wrapped between two heating films 22, and the heating films 22 are tightly attached to the outer surface of the heating tube 21, the heating resistance wire 23 can transfer heat through the inner heating film 22 to the outer surface of the heating tube 21, and then evenly transfer the heat to the coolant inside the heating tube 21 through heat conduction. Furthermore, the heating film 22 also has insulating properties, ensuring heating efficiency and electrical safety. When the temperature control switch 24 detects that the temperature of the outer heating film 22 exceeds the set threshold, the temperature control switch 24 disconnects. At this time, when the coolant temperature reaches 40℃, the temperature control switch 24 is forcibly disconnected to prevent the coolant temperature from becoming too high. Heating the battery cell 131 with liquid cooling can cause thermal runaway. Subsequently, the micro water pump 3 operates, delivering the coolant from the liquid cooling plate 12 to the heating tube 21. The heated coolant in the heating tube 21 is then pushed through the inlet pipe 133 and the connector 15 into the heat spreader 132. The hot coolant flowing into the heat spreader 132 heats the battery cell 131 through the tube wall, causing the temperature of the battery cell 131 to rise slowly. With the influence of external environmental radiation and the temperature of the battery cell 131... As the heat is absorbed by cell 31, the temperature of the coolant in the heat exchanger 132 gradually decreases. When it drops to 25°C, the vehicle sends a new command to heater 2. At this time, heater 2 restarts to heat the coolant in heating tube 21. This process is repeated until cell 131 is heated to the optimal working environment. At this time, heater 2 stops working. Because cell 131 is heated to the optimal working environment, not only is the winter range of cell 131 effectively improved, but the aging process of cell 131 is also reduced, thereby improving the service life of the battery itself.

[0026] During summer driving, the battery cell 131 generates heat through discharge. Due to heat accumulation, the temperature of the battery cell 131 gradually rises. When the temperature of the battery cell 131 reaches 45°C, the vehicle temperature triggers a command to start the micro water pump 3, enabling it to deliver coolant to the heating pipe 21. Because the heater 2 is in a stopped state, the coolant flowing through the heating pipe 21 is not heated. At this time, the coolant flowing into the heating pipe 21 flows into the heat exchanger 132 through the inlet pipe 133 and the connector 15. Since the heat exchanger 132 is in contact with the surface of the battery cell 131, the battery cell 131 generates heat through discharge. The generated heat is transferred through the wall of the heat spreader 132 to the coolant inside the heat spreader 132, allowing the coolant to absorb the heat generated by the battery cell 131. As the micro water pump 3 continues to deliver coolant into the heat spreader 132, the coolant that has absorbed heat is returned to the liquid cooling plate 12 through the connector 15 at the other end of the heat spreader 132. This allows the coolant in the liquid cooling plate 12 to continuously and rapidly cool the battery cell 131, and also enables the circulation of the coolant, accelerating the heat dissipation of the coolant in the liquid cooling plate 12, thereby improving the cooling effect on the battery cell 131.

[0027] The heating tube 21 is made of aluminum alloy, which effectively improves the heating tube 21 in terms of thermal conductivity, lightweight and corrosion resistance. In terms of thermal conductivity, aluminum has better thermal conductivity than steel. After the heating tube 21 is powered on, the aluminum alloy can transfer the heat of the heating film 22 to the internal coolant more quickly, and the thermal response speed is faster than that of the steel heating tube 21. In terms of lightweighting, aluminum has a lower density than copper, so aluminum heating tubes 21 can significantly reduce the total weight of the power battery system, indirectly improving the driving range or load capacity. In addition, aluminum is cheaper, easier to extrude and stamp, and has high processing efficiency, so its overall cost is lower than that of copper. In terms of corrosion resistance, aluminum easily forms a dense oxide film in the air, which can effectively resist the corrosion of coolant and humid air. Furthermore, the corrosion resistance of the aluminum alloy heating tube 21 can be further improved by anodizing.

[0028] The difference between Example 2 and Example 1 is as follows: The housing 1 has a liquid storage chamber 16 inside; the water outlet of the liquid cooling plate 12 is connected to the liquid storage chamber 16; the liquid storage chamber 16 is connected to the micro water pump 3; the water outlet of the micro water pump 3 is connected to the heater 2 through a hose 31.

[0029] In this embodiment, a partition 161 is fixedly installed inside the liquid storage chamber 16; the partition 161 divides the liquid storage chamber 16 into a first liquid storage chamber 162 and a second liquid storage chamber 163; the micro water pump 3 is connected to the second liquid storage chamber 163; the water outlet of the liquid cooling plate 12 is connected to the first liquid storage chamber 162; a connecting hole 164 is opened on the surface of the partition 161; a solenoid valve 165 is installed in the connecting hole 164; a traction unit is installed in the second liquid storage chamber 163; the traction unit is used to pull the temperature equalization tube 132 to slide inside the housing 1.

[0030] In this embodiment, the traction unit includes a sealing plate 17 and a steel wire rope 171; the sealing plate 17 is slidably and sealingly connected to the second liquid storage chamber 163; one end of the steel wire rope 171 is fixedly connected to the sealing plate 17, and the other end is connected to the temperature equalization pipe 132.

[0031] In this embodiment, two sets of lugs 135 are fixedly connected to the side of the heat equalization tube 132 near the shell cover 11; a connecting spring 111 connected to the lugs 135 is fixedly connected to the side of the shell cover 11 near the heat equalization tube 132; and the end of the wire rope 171 away from the sealing plate 17 is connected to the lugs 135.

[0032] In this embodiment, the surface of the heat exchanger 132 is coated with a graphene coating.

[0033] In this embodiment, the surface of the temperature distribution tube 132 is coated with an epoxy resin insulating coating; the thickness of the epoxy resin insulating coating is set to 0.2 mm.

[0034] During operation, the vehicle will generate continuous vibration. Since the heat exchanger tube 132 needs to be embedded in the narrow gap between the two rows of battery cells 131, the vibration will cause the battery cells 131 to squeeze the heat exchanger tube 132. If the heat exchanger tube 132 is too wide, it will be too rigid and will be prone to elastic bending under load. In order to consider the structural strength of the heat exchanger tube 132, the width of the heat exchanger tube 132 is set to be smaller than the height of the battery cells 131. However, the heat exchanger tube 132 with a smaller width cannot cool the battery cells 131 completely.

[0035] To address this, the present invention incorporates a traction unit that allows the heat exchanger tube 132 to slide up and down within the strip groove 14. This ensures that the effective contact area of ​​the sliding heat exchanger tube 132 covers the entire height range of the battery cell 131, guaranteeing sufficient heat exchange and achieving comprehensive cooling of the battery cell 131. Simultaneously, during the sliding process, the relative motion between the heat exchanger tube 132 and the surface of the battery cell 131 increases, thereby increasing the contact area between them, reducing contact thermal resistance, improving the heat transfer rate, and further enhancing the cooling effect on the battery cell 131.

[0036] In the initial state, the height of the strip groove 14 is greater than the width of the heat exchanger tube 132. The housing 1 includes an outer shell and a base plate. An installation pipe is installed at the water inlet end of the liquid cooling plate 12. A water inlet hole is opened at the lower end of the first liquid storage chamber 162. A solenoid valve is also installed in the water inlet hole and the installation pipe. The second liquid storage chamber 163 is filled with coolant. First, the liquid cooling plate 12 is embedded in the bottom of the base plate. Then, the outer shell is inverted to facilitate the installation of the base plate at the lower end of the outer shell. At this time, the installation pipe at the upper end of the liquid cooling plate 12 is aligned with the water inlet hole, so that the installation pipe can be sealed and inserted into the water inlet hole. Then, bolts are used to fix the outer shell and the base plate together, so that the liquid cooling plate 12... 2 is connected to the first liquid storage chamber 162. After the installation of the housing 1 is completed, the heat equalization pipe 132 is first connected to the cell 131 to form the cell assembly 13. Then the heater 2 and the water inlet pipe 133 are connected to the heat equalization pipe 132. Subsequently, the heater 2 is connected to the hose 31. Finally, the cell assembly 13 is placed into the housing. At this time, the end of the steel wire rope 171 away from the sealing plate 17 is tied to the hanging ear 135. The housing cover 11 is placed on top of the housing 1. The lower end of the connecting spring 111 at the lower end of the housing cover 11 is connected to the hanging ear 135. Finally, the housing cover 11 is placed on the upper end of the housing 1 to complete the assembly of the power battery.

[0037] During summer charging and discharging, battery cell 131 generates heat. Due to heat accumulation, the temperature of battery cell 131 gradually rises. At this time, the micro water pump 3 is activated, causing it to pump the coolant from the connected second storage chamber 163 to the heating tube 21. This allows the coolant entering the heating tube 21 to flow into the heat exchanger 132 via the inlet pipe 133. Meanwhile, the solenoid valve 165 in the connecting hole 164 is closed, preventing the coolant in the first storage chamber 162 from flowing into the second storage chamber 163, thus preventing the coolant in the second storage chamber from flowing into the second storage chamber 163. The increased negative pressure in the liquid chamber 163 causes the sealing plate 17 to move downward under the pull of the negative pressure. This causes the sealing plate 17 to pull the heat exchanger tube 132 upward through the lug 135 connected by the wire rope 171. The heat exchanger tube 132 then rises along the strip groove 14, making the rising heat exchanger tube 132 slide into contact with the outer surface of the battery cell 131. The coolant in the second liquid storage chamber 163 flows through the heat exchanger tube 132 and then into the liquid cooling plate 12 through the connector 15. The coolant in the liquid cooling plate 12 then flows into the first liquid storage chamber 162 through the water inlet and the installation pipe.

[0038] During the process of the sealing plate 17 pulling the heat exchanger tube 132 upward, the heat exchanger tube 132 will also squeeze the connecting spring 111 above, causing the connecting spring 111 to be compressed until the heat exchanger tube 132 is at the top of the strip groove 14. At this time, the solenoid valve 165 in the connecting hole 164 opens, and the solenoid valve in the water inlet and the mounting pipe opens, allowing the coolant in the liquid cooling plate 12 to flow into the first liquid storage chamber 162, which compresses the air in the first liquid storage chamber 162. The compressed air is above the liquid surface of the coolant in the first liquid storage chamber 162. When the first liquid storage chamber 162 and the second liquid storage chamber 16... When connected, the air pressure will push the coolant in the first liquid storage chamber 162 into the second liquid storage chamber 163 and push the sealing plate 17 to rise. At the same time, the weight of the heat exchanger tube 132, combined with the restoring force of the connecting spring 111, pushes the heat exchanger tube 132 to fall, so that the heat exchanger tube 132 pulls the sealing plate 17 to rise through the steel wire rope 171, so that the second liquid storage chamber 163 is continuously filled with coolant, so as to facilitate the injection of coolant into the heat exchanger tube 132 next time. At the same time, the heat exchanger tube 132 can slide up and down repeatedly in the strip groove 14, thereby increasing the cooling range of the surface of the battery cell 131 by the heat exchanger tube 132.

[0039] By coating the surface of the heat spreader 132 with a graphene coating, the surface of the heat spreader 132 becomes smooth, thereby reducing the friction between the heat spreader 132 and the battery cell 131, thus avoiding wear caused by the heat spreader 132 to the battery cell 131. At the same time, the graphene coating has high thermal conductivity, which not only does not increase the contact thermal resistance between the heat spreader 132 and the battery cell 131, but also improves the heat transfer efficiency between the heat spreader 132 and the battery cell 131, improving the heating or cooling effect of the heat spreader 132 on the battery cell 131. The graphene coating is usually a multi-layer structure, and the interlayer slippage can release stress. When the heat spreader 132 undergoes thermal expansion and contraction, the graphene coating releases stress by relying on interlayer slippage. In addition, the thickness of the graphene coating is set to 0.1 mm. The thinner graphene coating has less restriction on the expansion and contraction of the metal substrate and is less likely to generate internal stress, further reducing the impact of metal thermal expansion and contraction on the graphene coating.

[0040] By coating the surface of the heat exchanger 132 with an epoxy resin insulating coating, two advantages are achieved. First, the epoxy resin insulating coating has excellent insulation properties, allowing it to form a reliable electrical isolation barrier between the heat exchanger 132 and the battery cell 131, completely avoiding the risk of short circuits. Second, the epoxy resin insulating coating has excellent chemical corrosion resistance and wear resistance. Power battery electrolytes typically contain carbonate organic solvents and lithium salts, which are highly corrosive. Therefore, the epoxy resin insulating coating not only prevents electrolyte penetration and erosion but also reduces the risk of short circuits between the heat exchanger 132 and the battery cell 131. The wear between them greatly reduces the problem of electrolyte leakage in the power battery and improves the service life of the heat spreader 132 and the battery cell 131. In addition, epoxy resin has low thermal conductivity, so the thickness of the epoxy resin insulating coating is set to 0.2mm. This allows the 0.2mm thick epoxy resin insulating coating to retain insulation and chemical corrosion resistance while ensuring the heat conduction effect between the heat spreader 132 and the battery cell 131. Moreover, the epoxy resin insulating coating is flexible and has a certain deformation capacity. When the heat spreader 132 experiences thermal expansion and contraction, it can adapt to the expansion and contraction of the metal substrate.

[0041] Because the temperature rise of the battery cell 131 will trigger a thermal expansion effect, resulting in tiny and irregular local protrusions on the surface of the battery cell 131, if the heat spreader 132 is fixedly installed, the fixed heat spreader 132 can only fit with the initial contact area of ​​the battery cell 131. The uncontacted expansion area will create gaps, leading to air filling and thus increasing the contact thermal resistance between the heat spreader 132 and the battery cell 131. Therefore, the heat spreader 132 is designed to slide up and down in the narrow gap between the two rows of battery cells 131. Driven by vehicle vibration, the sliding heat spreader 132 actively squeezes and fits into the uncontacted expansion area, so that the microscopic depressions of the expansion area of ​​the heat spreader 132 and the battery cell 131 form a dynamic fit, squeezing out the original gaps and thus expanding the direct contact area between the heat spreader 132 and the battery cell 131. At the same time, the squeezing action of the heat spreader 132 completely squeezes out the air in the gap, reducing the thermal resistance of the air layer, thereby significantly reducing the contact thermal resistance and ensuring heat exchange efficiency.

[0042] In Example 3, two through grooves 134 are formed on the surface of the temperature equalization tube 132; the connecting nozzle 15 is installed in the through groove 134; the connecting nozzle 15 is rotatably and sealingly connected to the inner wall of the through groove 134; the connecting nozzle 15 includes a round cap 151 and a connecting tube 152; the round cap 151 and the connecting tube 152 are distributed on both sides of the through groove 134; the round cap 151 is threadedly connected to the connecting tube 152; a round hole 153 is formed on the surface of the connecting tube 152.

[0043] During operation, when installing the connector 15, simply insert the external threaded end of the connecting tube 152 of the connector 15 into one side of the through groove 134, and insert the internal threaded end of the round cover 151 into the other side of the through groove 134, so that the external threaded end of the connecting tube 152 contacts the internal threaded end of the round cover 151. Rotate the connecting tube 152 and the round cover 151 in opposite directions so that the connecting tube 152 and the round cover 151 are threadedly connected and combined to form the connector 15. At this time, the connector 15 is fixed in the through groove 134, and the round hole 153 on the surface of the connecting tube 152 is located in the through groove 134, so that the connector 15 communicates with the through groove 134 through the round hole 153. By setting the connector 15 for flexible installation, it is easy to adjust the orientation of the connector 15, which is convenient for connecting multiple sets of parallel heat exchange tubes 132, thus making it suitable for power battery packs of different capacities. It can also realize the rapid expansion of power battery packs, further improving the adaptability and convenience of the invention.

[0044] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A new type of heating system applied to power batteries, comprising a shell (1) and a shell cover (11); the shell cover (11) is fixedly connected with the shell (1); a liquid cooling plate (12) is installed at the bottom of the shell (1); an electric core assembly (13) is installed inside the shell cover (11); the electric core assembly (13) is located between the liquid cooling plate (12) and the shell cover (11); characterized in that: The battery cell assembly (13) includes a battery cell (131) and a heat spreader (132); multiple sets of battery cells (131) are provided; the heat spreader (132) is installed between two adjacent sets of battery cells (131); the heat spreader (132) is wavy; the contoured surface of the heat spreader (132) is in contact with the surface of the battery cell (131); a strip groove (14) is provided on the inner wall of the housing (1); both ends of the heat spreader (132) are slidably connected in the strip groove (14); and both ends of the heat spreader (132) are equipped with connectors (1). 5); A water inlet pipe (133) is provided on one side of the housing (1); The water inlet pipe (133) is connected to the connector (15) at one end of the temperature equalization pipe (132); A heater (2) is connected to the end of the water inlet pipe (133) away from the temperature equalization pipe (132); A miniature water pump (3) is installed on the side wall of the housing (1); One end of the miniature water pump (3) is connected to the water outlet of the liquid cooling plate (12), and the other end is connected to the heater (2); The connector (15) at the other end of the temperature equalization pipe (132) is connected to the water inlet of the liquid cooling plate (12). ​ 2. The novel heating system for power batteries according to claim 1, characterized in that: The heater (2) includes a heating tube (21); the surface of the heating tube (21) is covered with a heating film (22); the heating film (22) has two layers; a heating resistance wire (23) is wrapped between the two layers of the heating film (22); the two ends of the heating resistance wire (23) are connected to the positive and negative poles of the heating film (22); the heating film (22) is connected to a power source through a wire harness.

3. The novel heating system for power batteries according to claim 2, characterized in that: The surface of the heating tube (21) is fitted with a temperature control switch (24) connected to the heating film (22); the heating tube (21) is made of aluminum alloy material.

4. A novel heating system for power batteries according to claim 3, characterized in that: The housing (1) has a liquid storage chamber (16) inside; the water outlet of the liquid cooling plate (12) is connected to the liquid storage chamber (16); the liquid storage chamber (16) is connected to the micro water pump (3); the water outlet of the micro water pump (3) is connected to the heater (2) through a hose (31).

5. A novel heating system for power batteries according to claim 4, characterized in that: A partition (161) is fixedly installed inside the liquid storage chamber (16); the partition (161) divides the liquid storage chamber (16) into a first liquid storage chamber (162) and a second liquid storage chamber (163); the micro water pump (3) is connected to the second liquid storage chamber (163); the water outlet of the liquid cooling plate (12) is connected to the first liquid storage chamber (162); a connecting hole (164) is opened on the surface of the partition (161); a solenoid valve (165) is installed in the connecting hole (164); a traction unit is installed in the second liquid storage chamber (163); the traction unit is used to pull the temperature equalization tube (132) to slide inside the shell (1).

6. A novel heating system for power batteries according to claim 5, characterized in that: The traction unit includes a sealing plate (17) and a steel wire rope (171); the sealing plate (17) is slidably and sealingly connected in the second liquid storage chamber (163); one end of the steel wire rope (171) is fixedly connected to the sealing plate (17), and the other end is connected to the temperature equalization pipe (132).

7. A novel heating system for power batteries according to claim 6, characterized in that: Two sets of lugs (135) are fixedly connected to the side of the heat exchanger tube (132) near the shell cover (11); a connecting spring (111) connected to the lugs (135) is fixedly connected to the side of the shell cover (11) near the heat exchanger tube (132); the end of the wire rope (171) away from the sealing plate (17) is connected to the lugs (135).

8. A novel heating system for power batteries according to claim 7, characterized in that: The surface of the heat exchanger (132) is coated with a graphene coating.

9. A novel heating system for power batteries according to claim 7, characterized in that: The surface of the heat exchanger (132) is coated with an epoxy resin insulating coating; the thickness of the epoxy resin insulating coating is set to 0.2 mm.

10. A novel heating system for power batteries according to claim 9, characterized in that: The surface of the temperature equalization tube (132) has two through grooves (134); the connecting nozzle (15) is installed in the through groove (134); the connecting nozzle (15) is rotatably sealed to the inner wall of the through groove (134); the connecting nozzle (15) includes a round cap (151) and a connecting tube (152); the round cap (151) and the connecting tube (152) are distributed on both sides of the through groove (134); the round cap (151) and the connecting tube (152) are threadedly connected; the surface of the connecting tube (152) has a round hole (153).

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