Parallel-series flow channel stamping liquid cooling plate structure

Abstract

The invention relates to the technical field of liquid cooling plates, and discloses a parallel-series flow channel stamping liquid cooling plate structure which comprises a liquid cooling plate, a stamping flow channel plate is arranged in the liquid cooling plate, an upper plate is arranged in the liquid cooling plate, a liquid inlet is formed in the upper plate, a two-section part is arranged in the liquid inlet, and a two-section part is arranged in the two-section part. And four runners, namely a left three-runner and a right three-runner, are symmetrically arranged in the stamping runner plate and the upper plate, and two convex runners are arranged on the path of the left three-runner. According to the liquid cooling plate, the four flow channels, the three left flow channels, the three right flow channels, the protruding flow channels and other structures are arranged and connected in series, so that the single-path flowing path is shortened, the flowing resistance of cooling liquid is reduced, meanwhile, the problem that local heat dissipation of a traditional liquid cooling plate is insufficient is solved, good cold and heat uniformity and temperature uniformity of liquid cooling can be achieved, and the service life of the liquid cooling plate is prolonged. Therefore, the service life of the battery cell is prolonged.

Description

Technical Field

[0001] This invention relates to the field of liquid cooling plate technology, specifically to a parallel and series flow channel stamped liquid cooling plate structure. Background Technology

[0002] Liquid cooling plates are key components for heat dissipation in multi-cell battery systems. Their working principle is based on heat conduction and convection heat transfer mechanisms. When a battery cell generates heat during operation, the heat is first transferred to the internal flow channel walls via the liquid cooling plate substrate made of highly thermally conductive material. Simultaneously, driven by an external circulation pump, the coolant circulates within the flow channels at a certain flow rate. The coolant and the flow channel walls undergo convective heat transfer, thereby carrying away the heat dissipated by the battery cell and achieving the purpose of heat dissipation.

[0003] Currently, liquid cooling plates use a single series flow channel layout, resulting in a long heat dissipation path for the coolant. This increases flow resistance, requiring a high-power circulation pump to overcome this high resistance, thus increasing costs. Furthermore, the heat-generating areas of the battery cells are concentrated, making precise localized heat dissipation difficult and leading to significant localized heat accumulation. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a parallel-series flow channel stamped liquid cooling plate structure. This solves the problem that when a liquid cooling plate uses a single series flow channel layout, the coolant has a long heat dissipation path, which increases flow resistance. To overcome this high flow resistance, the system needs to be equipped with a high-power circulating pump, thus increasing the purchase cost. Furthermore, the heat-generating areas of the battery cell are concentrated, making it difficult to achieve precise local heat dissipation, resulting in significant local heat accumulation.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a parallel and series flow channel stamped liquid cooling plate structure, comprising a liquid cooling plate, a stamped flow channel plate disposed inside the liquid cooling plate, an upper plate disposed inside the liquid cooling plate, an inlet disposed inside the upper plate, and a bifurcation point disposed inside the inlet for the coolant to be diverted to the upper and lower sides of the liquid cooling plate at this point. The stamped flow channel plate and the upper plate are symmetrically provided with four flow channels, three left flow channels, and three right flow channels inside the plate. Two raised flow channels are disposed on the path of the left three flow channels, and three raised flow channels are disposed on the path of the right three flow channels. The four flow channels, the left three flow channels, and the right three flow channels are connected in series, so that the coolant flows into the serpentine flow channels after being diverted at the bifurcation point and then into the outlet to form a loop. A miniature electromagnetic regulating valve is disposed in each of the four flow channels, the left three flow channels, and the right three flow channels.

[0006] Preferably, the upper plate has a liquid outlet inside.

[0007] Preferably, the stamped flow channel plate has symmetrically arranged outlet single flow channels inside, and the side surface of the outlet single flow channel is connected to the liquid outlet.

[0008] Preferably, the four flow channels are connected to the outlet single flow channel.

[0009] Preferably, the upper surface of the liquid cooling plate is provided with 52 battery cell modules for simulating charging and discharging under condition 0.5.

[0010] Preferably, the bisection is located below the liquid inlet and consists of two 45° symmetrical guide slopes.

[0011] Preferably, the side surface at the bisection is connected to the four flow channels.

[0012] Preferably, the four flow channels, the left three flow channels, and the right three flow channels are symmetrically arranged on the stamping flow channel plate and the upper plate.

[0013] Preferably, a PLC controller is provided on the liquid cooling plate.

[0014] Working Principle: The coolant supplied by the external circulation system enters the liquid cooling plate through the inlet on the upper plate. Below the inlet, the coolant is divided into two streams, flowing to the upper and lower sides of the liquid cooling plate respectively. The coolant flowing to one side then enters the four channels symmetrically arranged on the upper plate and the stamped flow channel plate. After being further divided and refined by the left and right three channels, the coolant entering the left and right three channels flows along a serpentine path formed by 90° bends. This serpentine channel design extends the residence time of the coolant within the channels, allowing the coolant to interact more effectively with the channel walls. Sufficient contact allows for continuous heat removal from the battery cells through convection heat transfer. For areas with concentrated heat generation within the battery cells, two raised channels on the left third flow path and three raised channels on the right third flow path work simultaneously. The cross-sectional area of ​​the raised channels is larger than the main water channel, increasing the local coolant flow rate and simultaneously increasing the contact area with the heat-generating region, thus quickly removing concentrated heat and avoiding the problem of localized high-temperature accumulation in traditional liquid cooling plates. The PLC controller pre-stores the heating characteristic parameters of different specifications of battery cell modules; when a battery cell module is replaced, the PLC automatically calls up the corresponding parameters.

[0015] This invention provides a parallel-connected series flow channel stamped liquid cooling plate structure. It has the following beneficial effects:

[0016] 1. This invention optimizes coolant flow resistance from the source by setting up a structure with four flow channels, three left flow channels, three right flow channels, and raised flow channels in series. After the coolant is split at the inlet, it is split in parallel through the four flow channels, which shortens the single flow path. The left and right three flow channels cover the cell area in a serpentine series manner. The parallel and series flow channel layout reduces coolant flow resistance. There is no need to equip it with a high-power circulation pump during use. This structure saves energy and reduces the cost of adding or purchasing equipment.

[0017] 2. The present invention uses raised flow channels to target the concentrated heat-generating areas of the battery cell. The positions of these channels precisely correspond to the high-heat areas of the battery cell module, thereby enhancing convective heat transfer, solving the problem of insufficient local heat dissipation of traditional liquid cooling plates, and avoiding diaphragm shrinkage and electrolyte decomposition caused by high temperatures.

[0018] 3. The present invention features a double-sided four-channel system that evenly distributes coolant, with a serpentine flow path that fully covers the cell area. The maximum temperature of the 52 cells is 27.6-28.3℃, with a temperature difference of only 0.7℃. This avoids temperature differences caused by local over- or under-flow, ensuring cell consistency and achieving good thermal uniformity and temperature uniformity in liquid cooling, thereby improving the lifespan of the cells.

[0019] 4. This invention can be adapted to various specifications of battery cell modules and different charging and discharging conditions. By adjusting the flow rate, it can meet different heat dissipation requirements without replacing the liquid cooling plate, avoiding redundant energy consumption caused by fixed flow rate. In scenarios such as low temperature slow charging, it can reduce unnecessary flow rate and further reduce system energy consumption. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 This is a structural diagram of the stamped flow channel plate of the present invention;

[0022] Figure 3 This is a partial structural schematic diagram of the present invention;

[0023] Figure 4 These are diagrams 1 to 52 representing the battery cell module of the present invention;

[0024] Figure 5 This is a partial cross-sectional view of the flow channel of the present invention;

[0025] Figure 6 This is a graph showing the highest temperature data of the battery cell of the present invention.

[0026] The components include: 1. Liquid cooling plate; 2. 52 battery cell modules; 3. Stamped flow channel plate; 4. Liquid inlet; 5. Liquid outlet; 6. Top plate; 7. Four flow channels; 8. Left three flow channels; 9. Right three flow channels; 10. Raised flow channel; 11. Single flow channel at the outlet; 12. Two-way junction; 13. Flow channel height; and 14. Miniature electromagnetic regulating valve. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1:

[0029] Please see the appendix Figure 1 - Appendix Figure 4 This invention provides a parallel and series flow channel stamped liquid cooling plate structure, including a liquid cooling plate 1, a stamped flow channel plate 3 inside the liquid cooling plate 1, an upper plate 6 inside the liquid cooling plate 1, a liquid inlet 4 inside the upper plate 6, and a bifurcation point 12 inside the liquid inlet 4 for the coolant to be diverted to the upper and lower sides of the liquid cooling plate 1. The bifurcation point 12 is located below the liquid inlet 4 and consists of two 45° symmetrical guide slopes.

[0030] The liquid cooling plate 1 adopts a double-layer composite structure, which includes a stamped flow channel plate 3 and an upper plate 6, and is equipped with an inlet 4 and an outlet 5 for coolant entry and exit. To ensure structural sealing, thermal conductivity, and connection strength, the stamped flow channel plate 3, upper plate 6, inlet 4, and outlet 5 are fixedly connected by a vacuum brazing process. The vacuum brazing process uses Al-Si based brazing filler metal (Si content 12%), the welding temperature is controlled at 580℃-600℃, the holding time is 15-20 minutes, and the vacuum degree is ≤5×10⁻⁶. -3 Pa, the tensile strength of the welded joint is ≥120MPa, and the sealing performance meets the requirement of a leakage rate ≤1×10 Pa. -9 Pa·m 3 / s, the thermal conductivity of the connection part is ≥180W / (m·K), which avoids the risk of coolant leakage and ensures efficient heat transfer, laying the structural foundation for subsequent heat dissipation performance. The stamped flow channel plate 3 is made of 6061 aluminum alloy with a thermal conductivity of 201W / (m·K), formed by CNC stamping, with a plate thickness of 5mm. The overall size is adapted to the installation requirements of 52 battery cell modules and is used to open the flow channel system. The upper plate 6 is made of 5052 aluminum alloy with a plate thickness of 2mm. It is attached to the upper surface of the stamped flow channel plate 3 to form a closed flow channel cavity, and at the same time assists in conducting the heat of the battery cell to the coolant.

[0031] The interior of the stamped flow channel plate 3 and the upper plate 6 are symmetrically arranged with four flow channels 7, three left flow channels 8 and three right flow channels 9. Two raised flow channels 10 are arranged on the path of the three left flow channels 8, and three raised flow channels 10 are arranged on the path of the three right flow channels 9. The four flow channels 7, three left flow channels 8 and three right flow channels 9 are connected in series, so that the coolant flows into the serpentine flow channel after being divided at the bifurcation point 12 and then into the outlet 5 to form a loop. The four flow channels 7, three left flow channels 8 and three right flow channels 9 are symmetrically arranged on the stamped flow channel plate 3 and the upper plate 6.

[0032] Both the stamped flow channel plate 3 and the upper plate 6 are symmetrically equipped with four flow channels 7, three left flow channels 8, and three right flow channels 9. The three are arranged in parallel and series to form a complete serpentine flow channel loop. The four flow channels 7 serve as the primary distribution channel, and their inlet is connected to the side surface of the second-division 12. This allows the coolant after the second-division 12 to be distributed evenly to the three left flow channels 8 and three right flow channels 9. The three left flow channels 8 and three right flow channels 9 are symmetrically distributed on the liquid cooling plate 1. This structure is formed into a serpentine structure by a 90° bend, which extends the residence time of the coolant in the flow channel and ensures sufficient heat exchange with the battery cell. At the same time, two raised flow channels 10 are set on the path of the three left flow channels 8, and three raised flow channels 10 are set on the path of the three right flow channels 9. All raised flow channels 10 are integrally stamped with the main water channel. The position of the raised flow channels 10 corresponds to the concentrated heat generation area of ​​the battery cell. By increasing the local flow channel cross-sectional area, the coolant flow rate in the corresponding area is increased, thereby achieving localized and precise heat dissipation.

[0033] The side surface of the two-part section 12 is connected to the four-channel 7, and the four-channel 7 is connected to the outlet single-channel 11.

[0034] The stamped flow channel plate 3 has a symmetrically arranged outlet single flow channel 11, which is connected to the left three flow channel 8 and the right three flow channel 9. The outlet single flow channel 11 is used to collect the coolant that has completed heat exchange in the left three flow channel 8 and the right three flow channel 9.

[0035] The upper plate 6 has an outlet 5 inside, and the stamping flow channel plate 3 has symmetrical outlet single flow channels 11 inside, with the side surface of the outlet single flow channel 11 connected to the outlet 5.

[0036] The liquid outlet 5 inside the upper plate 6 extends to the outside of the upper plate 6 to connect to the external heat dissipation system, which is existing technology. The other end is connected to the side surface of the outlet single flow channel 11, which can lead the high-temperature coolant after the outlet single flow channel 11 to the liquid cooling plate 1, forming a complete cooling circuit of inlet 4, bisection 12, four flow channels 7, left three flow channels 8, right three flow channels 9, outlet single flow channel 11, and outlet 5, ensuring the coolant circulation and continuously removing the heat from the battery cell. In this application, the flow channel height 13 is 4.5mm, and the depth of the flow channel groove opened on the stamped flow channel plate 3 is 4.5mm. There is no local height difference when this height is set.

[0037] The upper surface of the liquid cooling plate 1 is provided with 52 battery cell modules 2 for simulating charging and discharging under condition 0.5.

[0038] Fifty-two battery cell modules 2 are mounted on the upper surface of the liquid cooling plate 1. These 52 cells are attached and fixed to the upper surface of the liquid cooling plate 1 using thermally conductive silicone for heat dissipation performance simulation testing. The simulation test conditions were set as follows: the 52 battery cell modules 2 were charged and discharged at a rate of 0.5C; the coolant was a 50% ethylene glycol-water solution with a flow rate of 6.5 L / min; and the initial temperature was 20℃. The test results showed that the flow resistance of the liquid cooling plate 1 was only 14.3 kPa, far lower than that of a traditional single-channel liquid cooling plate 1 (which typically has a flow resistance > 25 kPa). Simultaneously, the highest temperature data for each battery cell was extracted, with a maximum of 28.3℃ and a minimum of 27.6℃, and the temperature difference between the highest temperatures of the cells was only 0.7℃. This parallel and series flow channel stamped liquid cooling plate 1 structure with raised flow channels 10 enables efficient local heat dissipation of the coolant in the cell area of ​​the liquid cooling plate 1, avoiding excessively high temperatures in concentrated heat-generating areas. The parallel structure formed by the bisection 12 and the four flow channels 7 significantly shortens the length of a single flow channel, reduces the flow resistance of the liquid cooling plate 1, and improves heat dissipation capacity. Through the symmetrical layout and uniform distribution of the flow channel system, the coolant flow deviation in each area of ​​the liquid cooling plate 1 is ≤5%, effectively reducing the temperature difference of the cells and enabling the liquid cooling to achieve good heat and cold uniformity and temperature uniformity. Ultimately, the cycle life of the 52-cell module 2 can be increased from 1200 cycles with traditional liquid cooling plates to more than 1560 cycles, significantly improving the service life of the cells.

[0039] Miniature electromagnetic regulating valves 14 are installed in the four-channel 7, the left three-channel 8, and the right three-channel 9, and a PLC controller is installed on the liquid cooling plate 1.

[0040] The miniature electromagnetic regulating valve 14 has a 316L stainless steel body, which is resistant to coolant corrosion and compatible with 50% ethylene glycol-water solution. The valve core has a conical structure (adjustment accuracy ±0.5% opening), a response time ≤100ms, and a working pressure range of 0.1-0.5MPa. Its diameter matches the width of the four-channel 7, the left three-channel 8, and the right three-channel 9, ensuring no additional flow resistance changes during flow regulation. The miniature electromagnetic regulating valve 14 receives signals from the PLC controller and adjusts the valve core opening to change the flow area of ​​the sub-channels, achieving precise control of the flow rate in a single channel. This design is adaptable to various battery cell modules and different charging and discharging conditions. By adjusting the flow rate, it meets different heat dissipation requirements without replacing the liquid cooling plate 1, avoiding redundant energy consumption caused by fixed flow rates. In scenarios such as low-temperature slow charging, it reduces unnecessary flow. Combined with the original low flow resistance of 14.3kPa, it further reduces system energy consumption and extends the battery cell cycle life. The PLC controller pre-stores the heating characteristic parameters of different specifications of battery cell modules. When a battery cell module is replaced, the PLC automatically calls up the corresponding parameters after the sensor identifies the module model. For small-volume battery cells, the micro electromagnetic regulating valve 14 of the corresponding area can be adjusted individually without replacing the liquid cooling plate 1. During use, when replacing a small-volume battery cell module, the radio frequency identification (RFID) sensor installed on the upper surface of the liquid cooling plate 1 reads the electronic tag on the module shell to complete the model identification and transmits it to the PLC controller. The PLC automatically matches the database parameters and generates targeted adjustment instructions without manual input or replacement of the liquid cooling plate 1 hardware.

[0041] Example 2:

[0042] Please see the appendix Figure 5 - Appendix Figure 6 The following tests were conducted on the heat dissipation performance of the 52 battery cell modules 2 and the flow resistance control performance of the liquid cooling plate 1 in this application to verify and connect the technical effectiveness of the flow channel stamping liquid cooling plate 1 structure in terms of low flow resistance and high temperature uniformity.

[0043] Experimental objective:

[0044] This experiment revolves around Figure 6 The performance verification of the 52-cell module cell 2, based on the highest temperature data, is carried out. The core objective is to comprehensively verify and demonstrate the technical effectiveness of the series flow channel stamping liquid cooling plate 1 structure by simulating the actual working scenario of a multi-cell module.

[0045] Experimental preparation:

[0046] Battery testing system: Model CT-4008-5V100A, used to apply 0.5C constant current charge and discharge cycle to 52 cell modules, and precisely control the charging current (26A), discharging current (26A) and cutoff voltage (charging to 4.2V, discharging to 2.75V);

[0047] Coolant circulation system: including circulation pump (adjustable power, minimum 30W), constant temperature water tank (temperature control accuracy ±0.5℃), flow meter (range 0-10L / min, accuracy ±0.1L / min), used to provide 6.5L / min, 20℃ 50% ethylene glycol-water solution coolant;

[0048] Pressure testing system: includes a high-precision pressure sensor (range 0-50kPa, accuracy ±0.1kPa), which is installed at the inlet 4 and outlet 5 of the liquid cooling plate 1 respectively, for measuring flow resistance;

[0049] Temperature acquisition system: includes 52 K-type thermocouples (temperature measurement accuracy ±0.1℃) and a data acquisition instrument (sampling frequency 10Hz), used to synchronously acquire the highest temperature of each cell;

[0050] Helium mass spectrometer leak detector: Model H2000, leak detection accuracy ≤1×10⁻⁶ -9 Pa·m 3 / s, used to test the sealing performance of liquid cooling plates.

[0051] Experiment content:

[0052] The test uses a battery testing system to apply a 0.5C constant current charge-discharge cycle (charging current 26A, charging to 4.2V cutoff; discharging current 26A, discharging to 2.75V cutoff) to 52 cell modules.

[0053] The test used a 50% ethylene glycol-water solution as the coolant, with an initial temperature of 20°C. The flow rate was controlled at 6.5 L / min by a circulating pump. The flow path of the coolant in the liquid cooling plate 1 was as follows: inlet 4, bisection 12, four-channel 7, left three-channel 8 (via raised channel 10), right three-channel 9 (via raised channel 10), outlet single channel 11, and outlet 5.

[0054] Temperature data was collected during the process, using K-type thermocouples (temperature measurement accuracy ±0.1℃) attached to the top center of each of the 52 battery cells (corresponding to...). Figure 6 The highest temperature data of the cells (numbered 1-52) is collected every 10 seconds for three consecutive charge-discharge cycles. The temperature data of the stable cycle (the second cycle) is taken as the final result.

[0055] Test results:

[0056] The highest temperature of cells 1-52 fluctuated between 27.6℃ and 28.3℃. Among them, the highest temperature of the edge cells (cells 1, 7, 13, 25, 37, and 49) was 27.6℃-27.8℃, while the highest temperature of the central area cells (cells 26, 38, and 50, corresponding to the area covered by the raised flow channel 10) was 28.0℃-28.3℃, with no localized overheating points. The maximum temperature of the 52 cells was 28.3℃, and the minimum temperature was 27.6℃, with a maximum temperature difference of 0.7℃ between cells, which is better than that of traditional single-channel liquid cooling plates (temperature difference is usually >2℃). Under the above test conditions, the flow resistance of the liquid cooling plate 1 was measured by pressure sensors (accuracy ±0.1kPa) at the inlet and outlet 5, and the result was 14.3kPa, proving that the parallel flow splitting structure effectively reduces flow resistance and can maintain stable coolant circulation without the need for a high-power circulating pump. This application achieves good thermal uniformity and temperature uniformity by using uniform current distribution at the bisection 12 and local enhanced heat dissipation at the raised flow channel 10 to control the maximum temperature difference of the battery cell to 0.7℃. At the same time, the low flow resistance characteristic of 14.3kPa reduces system energy consumption and ultimately extends the cycle life of the 52 battery cell modules 2, meeting the long-term stable operation requirements of multi-cell systems in the new energy field.

Claims

1. A parallel-connected flow channel stamped liquid cooling plate structure, comprising a liquid cooling plate (1), wherein a stamped flow channel plate (3) is disposed inside the liquid cooling plate (1), an upper plate (6) is disposed inside the liquid cooling plate (1), and a liquid inlet (4) is disposed inside the upper plate (6), characterized in that, The inlet (4) is provided with a split point (12) for the coolant to be diverted to the upper and lower sides of the liquid cooling plate (1). The stamped flow channel plate (3) and the upper plate (6) are symmetrically provided with four flow channels (7), three left flow channels (8) and three right flow channels (9). Two raised flow channels (10) are provided on the path of the three left flow channels (8), and three raised flow channels (10) are provided on the path of the three right flow channels (9). The four flow channels (7), three left flow channels (8) and three right flow channels (9) are connected in series for the coolant to flow into the serpentine flow channel after being diverted at the split point (12) and then to the outlet to form a loop. Each of the four flow channels (7), three left flow channels (8) and three right flow channels (9) is provided with a miniature electromagnetic regulating valve (14).

2. The parallel-connected flow channel stamped liquid cooling plate structure according to claim 1, characterized in that, The upper plate (6) is provided with a liquid outlet (5).

3. The parallel-connected flow channel stamped liquid cooling plate structure according to claim 2, characterized in that, The stamping flow channel plate (3) is symmetrically provided with an outlet single flow channel (11), and the side surface of the outlet single flow channel (11) is connected to the liquid outlet (5).

4. The parallel-connected flow channel stamped liquid cooling plate structure according to claim 3, characterized in that, The four-channel (7) is connected to the single-channel outlet (11).

5. The parallel-connected flow channel stamped liquid cooling plate structure according to claim 1, characterized in that, The upper surface of the liquid cooling plate (1) is provided with 52 battery cell modules (2) for simulating charging and discharging under 0.5 conditions.

6. The parallel-connected flow channel stamped liquid cooling plate structure according to claim 1, characterized in that, The bisection (12) is located below the liquid inlet (4) and consists of two 45° symmetrical guide slopes.

7. The parallel-connected flow channel stamped liquid cooling plate structure according to claim 1, characterized in that, The side surface of the bisection (12) is connected to the four-channel (7).

8. The parallel-connected flow channel stamped liquid cooling plate structure according to claim 1, characterized in that, The four flow channels (7), the left three flow channels (8), and the right three flow channels (9) are symmetrically arranged on the stamping flow channel plate (3) and the upper plate (6).

9. The parallel-connected flow channel stamped liquid cooling plate structure according to claim 1, characterized in that, A PLC controller is installed on the liquid cooling plate (1).

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