Battery pack thin sheet micro-channel liquid cooling plate heat dissipation system

Abstract

The utility model belongs to industrial and electronic equipment heat dissipation technical field discloses a kind of battery pack sheet microchannel liquid cooling plate heat dissipation system, it includes: water system, liquid cooling plate, battery pack;Battery pack is stacked into group by multiple electric core (1), and the outer side surface of two end electric core (1) and between two adjacent electric core (1) respectively arrange liquid cooling plate, and liquid cooling plate connects water system, provides liquid cooling heat dissipation for electric core (1).The utility model sheet microchannel liquid cooling plate heat dissipation system heat dissipation effect is good, and heat dissipation rate is not less than 2.18 DEG C / min;More direct heat dissipation arrangement, compared with conventional liquid cooling arrangement, larger heat dissipation contact surface, shorter heat transfer path;Battery pack overall temperature difference is small, and the temperature difference of single electric core is small, and maximum temperature difference is ≤1 DEG C, with better thermal equilibrium;Adopt microchannel sheet liquid cooling plate, heat dissipation effect is good, compact structure is applicable to high energy density, large rate discharge battery pack heat dissipation, supports 10C large rate discharge scene.

Description

Technical Field

[0001] This utility model belongs to the field of heat dissipation technology of industrial and electronic equipment, and relates to liquid cooling heat dissipation of energy storage battery packs. It is a liquid cooling system that uses thin-film microchannel liquid cooling plates for heat dissipation, and has the characteristics of direct heat transfer, compact space, and ensuring the heat dissipation uniformity of the battery pack. Background Technology

[0002] With the increasing demand for regulation capabilities in power systems and the continuous expansion of new energy development and consumption, the demand for high-power applications is also increasing, such as laser anti-drone systems and electric mining trucks. These applications require energy storage systems to provide higher power density to accommodate more compact installation spaces. Higher operating power also leads to greater heat generation in the energy storage battery system itself. Temperature is a key factor affecting lithium battery performance, and high temperatures have a dual impact on power batteries. On the one hand, as temperature rises, electrolyte activity increases, ion diffusion accelerates, and battery internal resistance decreases, improving battery performance. On the other hand, higher temperatures can lead to harmful reactions such as electrode degradation and electrolyte decomposition, affecting battery life and even causing permanent damage to the battery's internal structure. Studies show that chemical reaction rates are exponentially related to temperature; for every 10°C increase in temperature, the chemical reaction rate doubles. At an ambient temperature of +45°C, the cycle life of lithium batteries decreases by approximately 60%. During high-rate charging, a 5°C increase in temperature results in a significant reduction in battery life. In addition, battery systems often suffer from uneven internal heat generation during operation. Since the internal resistance of the battery body, battery tabs, and current collectors connecting the batteries are all different, the difference in heat generation is particularly noticeable when operating at high power. All of these factors can lead to a reduction in the lifespan of the battery energy storage system.

[0003] With the development of the energy storage industry, miniaturization and lightweighting are also required, which places dual demands on both size and output power. Battery packs are further developing towards higher energy density and miniaturization, inevitably leading to increasingly higher heat flux density per unit volume. In terms of heat dissipation methods, air cooling requires sufficient space for airflow design, which is contrary to the development trend. In contrast, liquid cooling is easier to integrate, tends towards miniaturization and lightweighting, and is developing towards microchannels. Liquid cooling uses coolant as a medium, relying on the principle of convection heat transfer to remove heat through fluid flow. To further improve heat dissipation efficiency and thermal balance during the heat dissipation process...

[0004] In conclusion, a suitable operating temperature is a prerequisite for optimal battery performance. Therefore, developing an effective liquid cooling system that can stably and efficiently control battery pack temperature and ensure the overall normal operation of the battery pack is of great significance. Utility Model Content

[0005] (I) Purpose of the utility model

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a liquid cooling system for battery packs with good heat dissipation effect and balanced heat dissipation.

[0007] (II) Technical Solution

[0008] To solve the above-mentioned technical problems, this utility model provides a battery pack thin-film microchannel liquid cooling plate heat dissipation system, which includes: a water circuit system, a liquid cooling plate, and a battery pack; the battery pack is composed of multiple battery cells 1 stacked together, and liquid cooling plates are arranged on the outer sides of the battery cells 1 at both ends and between two adjacent battery cells 1, and the liquid cooling plates are connected to the water circuit system to provide liquid cooling heat dissipation for the battery cells 1.

[0009] Furthermore, the battery pack also includes a connecting copper busbar 3 and an end copper busbar 4. Multiple battery cells 1 are stacked in a horizontal plane along the thickness direction and connected in series through the connecting copper busbar 3. Energy is then output through the end copper busbar 4 located at both ends of the electromagnetic group.

[0010] Furthermore, a limiting end plate 2 is provided on the outer side of the battery cell 1 at both ends of the battery pack, and the limiting end plate 2 limits the position; the limiting end plate 2 is provided with a reserved hole, and is connected to the external bottom fixing structure by screws.

[0011] Furthermore, the battery pack and the outer periphery of the liquid cooling plate are fixed by a limiting plastic steel strap 5.

[0012] Furthermore, the battery pack uses square lithium-ion cells arranged horizontally in groups along the thickness direction.

[0013] Furthermore, the water system includes an inflow water system unit and an outflow water system unit. The inflow water system unit is connected to the inlet of each liquid cooling plate, and the outflow water system unit is connected to the outlet of each liquid cooling plate.

[0014] Furthermore, the inflow water channel unit includes a primary inflow water channel 6 and a secondary inflow water channel 7. The primary inflow water channel 6 and the secondary inflow water channel 7 are connected to form a whole. The fluid first flows in through the inlet of the primary inflow water channel 6, and then is diverted through the primary inflow water channel 6 to enter each of the secondary inflow water channels 7. Each secondary inflow water channel 7 is connected to the inlet of the corresponding liquid cooling plate.

[0015] Furthermore, the outflow water path unit includes a primary outflow water path 8 and a secondary outflow water path 9. The primary outflow water path 8 and the secondary outflow water path 9 are connected to form a whole. Each secondary outflow water path 9 is connected to the outlet of the corresponding liquid cooling plate. The fluid flows out from each secondary outflow water path 9 and finally flows out of the system for circulation after converging in the primary outflow water path 8.

[0016] Furthermore, the liquid cooling plate includes an end liquid cooling plate 10 and a middle liquid cooling plate 11. The two end liquid cooling plates 10 are arranged at the end of the battery pack, with only one surface in contact with the side of the cell. The middle liquid cooling plate 11 is arranged at intervals with the cell 1 and forms a whole by being fixed by the limiting end plate 2.

[0017] Furthermore, flow channels 12 are provided on both the end liquid cooling plate 10 and the middle liquid cooling plate 11. The inlet of the flow channel is connected to the secondary inflow water path 7, and the outlet of the flow channel is connected to the secondary outflow water path 9.

[0018] In the thin-film microchannel liquid cooling plate heat dissipation system, fluid enters the entire system through a primary inflow channel. After being diverted, it enters various secondary inflow channels and then flows into the channels of each liquid cooling plate. The liquid cooling plates are arranged on the side of the battery pack. When the battery pack discharges and heats up, the internal heat is transferred to the surface from the inside out through thermal conduction. Through contact with the liquid cooling plates, the fluid flow directly carries away the generated heat in the form of convective heat transfer. The fluid, having received heat and gradually heated, flows out of the outlet of the liquid cooling plate through the channels and enters the connected secondary outflow channel. The fluid in each secondary outflow channel finally converges through the primary outflow channel and flows out of the entire liquid cooling system, entering the refrigeration cycle.

[0019] (III) Beneficial Effects

[0020] The battery pack thin-film microchannel liquid cooling plate heat dissipation system provided by the above technical solution has the following beneficial effects:

[0021] (1) The thin-film microchannel liquid cooling plate heat dissipation system has good heat dissipation effect and a heat dissipation rate of not less than 2.18℃ / min.

[0022] (2) The heat dissipation arrangement is more direct, with a larger heat dissipation contact surface and a shorter heat transfer path compared to conventional liquid cooling arrangements.

[0023] (3) The overall temperature difference of the battery pack is small, the temperature difference of a single cell is small, and the maximum temperature difference is ≤1℃, which has better thermal balance.

[0024] (4) It adopts a microchannel thin-film liquid cooling plate, which has good heat dissipation effect and compact structure. It is suitable for heat dissipation of battery packs with high energy density and high discharge rate, and supports 10C high discharge rate scenarios. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0026] Figure 2 This is a top view of the present invention;

[0027] Figure 3 This is a diagram of the liquid cooling path system of this utility model;

[0028] Figure 4 This is a schematic diagram of the thin-film microchannel liquid cooling plate structure of this utility model. Detailed Implementation

[0029] To make the objectives, contents, and advantages of this utility model clearer, the specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples.

[0030] like Figures 1 to 4 As shown, a battery pack thin-film microchannel liquid cooling plate heat dissipation system includes a water circuit system, a liquid cooling plate, and a battery pack. The battery pack consists of multiple battery cells 1 stacked together. Liquid cooling plates are arranged on the outer sides of the battery cells 1 at both ends and between two adjacent battery cells 1. The liquid cooling plates are connected to the water circuit system to provide liquid cooling heat dissipation for the battery cells 1.

[0031] Furthermore, the battery pack also includes a limiting end plate 2, a connecting copper busbar 3, an end copper busbar 4, and a limiting plastic steel strip 5.

[0032] Multiple battery cells 1 are stacked in a horizontal plane along the thickness direction, connected in series by connecting copper busbars 3, and then output through the end copper busbars 4 located at both ends of the electromagnetic group.

[0033] Limiting end plates 2 are provided on the outer side of the cells 1 at both ends of the battery pack, and the cells are limited by the limiting end plates 2; the limiting end plates 2 are provided with reserved holes, and are connected to the external bottom fixing structure by M8 and M5 screws.

[0034] The entire battery pack and liquid cooling plate are secured by limiting plastic steel straps 5, ensuring the overall stability of the battery pack.

[0035] The battery pack uses square lithium-ion cells arranged horizontally along the thickness direction. Cell 1 and the liquid cooling plate are arranged in a "sandwich" configuration, with multiple fluid regions present.

[0036] The water system comprises a primary inflow channel 6, a primary outflow channel 8, a secondary inflow channel 7, and a secondary outflow channel 9. The primary inflow channel 6 and the secondary inflow channel 7 are connected to form a single unit, as are the primary outflow channel 8 and the secondary outflow channel 9. Fluid first flows in through the inlet of the primary inflow channel 6, then is diverted through the primary inflow channel 6 into each of the secondary inflow channels 7. The fluid then flows out through each of the secondary outflow channels 9, finally converging at the primary outflow channel 8 before exiting the system for circulation.

[0037] The liquid cooling plate comprises end liquid cooling plates 10, middle liquid cooling plates 11, and flow channels 12. Each liquid cooling plate is spaced apart and directly contacts the side of each cell 1. Two end liquid cooling plates 10 are located at the end of the battery pack, with only one surface in contact with the side of the cell. The middle liquid cooling plate 11 is spaced apart from the cell 1 and forms a whole by being fixed by a limiting end plate 2. The inlet of each liquid cooling plate is connected to the secondary inflow channel 7, and the outlet is connected to the secondary outflow channel 9. Fluid flows into each liquid cooling plate and enters the flow channel within each liquid cooling plate. There are three alternative flow channels, flowing in from the inlet and out from the outlet.

[0038] Heat dissipation principle explanation: During discharge, cell 1 generates heat at different temperatures at its body and the connection point with the electrodes. This heat is transferred from the inside out to the surface via thermal conduction. The end liquid cooling plates 10 and the central liquid cooling plate 11 are in contact with the surface of cell 1. These have a large contact area, meaning a large heat dissipation area. Fluid flows into the liquid cooling plates and along the flow channels, carrying away heat from the surface of cell 1 according to the principle of convection heat transfer. Cell 1 is a square lithium battery, and its heat transfer path is shorter in the thickness direction, resulting in more direct heat transfer. Therefore, the liquid cooling plates are arranged on the sides of cell 1. The central liquid cooling plate 11 has cells 1 on both sides, receiving double heating, while the end liquid cooling plates 10 only contact one cell 1 on their sides, resulting in better heat exchange but a smaller temperature difference. A 50% ethylene glycol solution is used as the fluid, which has advantages such as high thermal conductivity, low viscosity, and resistance to freezing at low temperatures. It can quickly carry away heat through the flow channels and can also cope with extreme low or high temperatures. The fluid first flows into the primary inlet channel 6. Within this channel, the fluid maintains a uniform temperature throughout, as it has not yet come into contact with the battery cells. It then flows through the secondary inlet channels 7, again maintaining a consistent temperature. This ensures that the fluid temperature remains constant until it reaches each liquid-cooled plate to dissipate heat from each battery cell 1, a crucial guarantee for thermal balance. Once in the liquid-cooled plates, the microchannel design with its small diameter and high flow rate allows for rapid heat removal, with a temperature difference of ≤1℃, ensuring excellent thermal balance. This guarantees consistent heat exchange for each battery cell 1, preventing the fluid from gradually heating up and reducing its subsequent heat exchange capacity. After cooling each battery cell 1, the fluid exits through the secondary outlet channel 9 and then flows out of the system again through the primary outlet channel 8 for further circulation.

[0039] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A battery pack thin-film microchannel liquid cooling plate heat dissipation system, characterized in that, include: Water system, liquid cooling plate, battery pack; the battery pack consists of multiple cells (1) stacked together. Liquid cooling plates are arranged on the outer side of the cells (1) at both ends and between two adjacent cells (1). The liquid cooling plates are connected to the water system to provide liquid cooling for the cells (1).

2. The battery pack thin-film microchannel liquid cooling plate heat dissipation system as described in claim 1, characterized in that, The battery pack also includes connecting copper busbars (3) and end copper busbars (4). Multiple cells (1) are stacked in a horizontal plane along the thickness direction and connected in series through connecting copper busbars (3). Energy is then output through the end copper busbars (4) located at both ends of the electromagnetic group.

3. The battery pack thin-film microchannel liquid cooling plate heat dissipation system as described in claim 2, characterized in that, Limiting end plates (2) are provided on the outer side of the cells (1) at both ends of the battery pack, and the cells are limited by the limiting end plates (2); the limiting end plates (2) are provided with reserved holes, and are connected to the external bottom fixing structure by screws.

4. The battery pack thin-film microchannel liquid cooling plate heat dissipation system as described in claim 3, characterized in that, The battery pack and the outer periphery of the liquid cooling plate are fixed by a limiting plastic steel strap (5).

5. The battery pack thin-film microchannel liquid cooling plate heat dissipation system as described in claim 4, characterized in that, The battery pack uses square lithium-ion cells arranged horizontally along the thickness direction.

6. The battery pack thin-film microchannel liquid cooling plate heat dissipation system as described in claim 5, characterized in that, The water system includes an inflow water system unit and an outflow water system unit. The inflow water system unit is connected to the inlet of each liquid cooling plate, and the outflow water system unit is connected to the outlet of each liquid cooling plate.

7. The battery pack thin-film microchannel liquid cooling plate heat dissipation system as described in claim 6, characterized in that, The inflow water channel unit includes a primary inflow water channel (6) and a secondary inflow water channel (7). The primary inflow water channel (6) and the secondary inflow water channel (7) are connected to form a whole. The fluid first flows in through the inlet of the primary inflow water channel (6), and then is diverted through the primary inflow water channel (6) to enter each secondary inflow water channel (7). Each secondary inflow water channel (7) is connected to the inlet of the corresponding liquid cooling plate.

8. The battery pack thin-film microchannel liquid cooling plate heat dissipation system as described in claim 7, characterized in that, The outflow water path unit includes a primary outflow water path (8) and a secondary outflow water path (9). The primary outflow water path (8) and the secondary outflow water path (9) are connected to form a whole. Each secondary outflow water path (9) is connected to the outlet of the corresponding liquid cooling plate. The fluid flows out from each secondary outflow water path (9) and finally flows out of the system after converging in the primary outflow water path (8) for circulation.

9. The battery pack thin-film microchannel liquid cooling plate heat dissipation system as described in claim 8, characterized in that, The liquid cooling plate includes an end liquid cooling plate (10) and a middle liquid cooling plate (11). The two end liquid cooling plates (10) are arranged at the end of the battery pack, with only one surface in contact with the side of the cell. The middle liquid cooling plate (11) is arranged at intervals with the cell (1) and is fixed as a whole by the limiting end plate (2).

10. The battery pack thin-film microchannel liquid cooling plate heat dissipation system as described in claim 9, characterized in that, Both the end liquid cooling plate (10) and the middle liquid cooling plate (11) are provided with flow channels (12), the inlet of the flow channel is connected to the secondary inflow channel (7), and the outlet of the flow channel is connected to the secondary outflow channel (9).

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