CN110880631A - Be applied to curved type variable structure cooling plate of power battery module - Google Patents

Abstract

The invention discloses a curved variable-structure cooling plate applied to a power battery module, which comprises two parallel runners, wherein the runners are continuous curved runners, and the cross section area of the runners is changed in a non-equal gradual manner along the flowing direction of heat-conducting liquid in the runners; meanwhile, outer end flow guide ports for inputting and outputting heat conducting liquid are respectively arranged at two ends of the cooling plate corresponding to the flow channel; the invention also discloses a power battery module with the liquid cooling assembly, which comprises battery monomers, insulating heat-conducting fins, a cooling plate, a busbar and a battery mounting plate, wherein the battery monomers are arranged in parallel and are provided with certain intervals, the busbar is buckled at the position of a lug, the outer side of the busbar is limited and fixed by the battery mounting plate, and the insulating heat-conducting fins and the cooling plate are sequentially arranged at the two sides. The invention can control the temperature of the battery within a reasonable range and further reduce the temperature difference in the battery module.

Description

A curved variable structure cooling plate applied to power battery modules

technical field

The invention relates to the field of power battery heat dissipation, in particular to a curvilinear variable structure cooling plate with a plug-in structure and applied to a power battery module.

Background technique

Lithium-ion batteries have become the first choice for clean energy to replace fossil fuels due to their high single-cell voltage, large specific energy, wide suitable operating temperature range, and long service life. They are widely used in new energy electric vehicles as power batteries.

The power battery is the heart of an electric vehicle. The internal temperature rise and temperature uniformity of the battery module are important indicators to measure the power supply performance, safety performance and stable performance of the battery. If the temperature is too high, the side reactions of the battery will be accelerated, resulting in the attenuation of battery capacity, working voltage, and charge-discharge efficiency. It will be significantly reduced and even cause irreversible decay of battery capacity. For electric vehicles, each battery cell is connected in series or in parallel to form a group. If individual battery cells fail in advance, the performance of the entire battery pack will be affected, and the electric vehicle will not be able to operate normally. Therefore, it is undoubtedly of great significance to use a reasonable and efficient thermal management system to control the temperature and consistency of the battery within a reasonable range, improve the performance of the battery and prolong its service life, so as to ensure the safe and reliable operation of electric vehicles. The channel structure research has a more critical impact on temperature control and temperature consistency.

At present, according to different heat transfer media, the cooling methods of the power battery thermal management system can be divided into three categories: air cooling, liquid cooling, and phase change cooling. Among them, due to its own heat dissipation limitations, air cooling is difficult to meet the heat dissipation requirements of batteries under high load conditions; liquid cooling is widely used due to its high cooling efficiency and reliability; phase change material cooling can be well maintained. The temperature of the battery pack is uniform and the heat dissipation effect is good, but the phase change material has high requirements and is expensive, which is greatly limited by materials and costs. Therefore, the use of liquid-cooled thermal management structure for power battery heat dissipation is considered to be the primary choice for the structural design of the vehicle thermal management system.

The cooling plate flow channel design of the current power battery liquid cooling system mainly includes curved, straight channel, single-cavity structure, etc., and on this basis, the distribution positions of different cooling liquid inlet and outlet, the number of shunt channels, and the cooling plate flow are derived. other runner types such as the number of channels. Because the curved asymmetric channel cooling plate design has better structural integrity and support than the single-cavity structure, it can reduce the channel area and coolant consumption compared with the straight channel, and the temperature uniformity is better compared with the curved symmetrical channel design , therefore, it can be used as a preferred solution and its structure can be optimized to obtain better liquid cooling and heat dissipation effect of the battery module.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a cooling plate with variable structure of curved shape applied to a power battery module. The cooling plate has a variable structure of the flow channel made according to the distribution law of the temperature field of the battery on the basis of the traditional curved flow channel. The asymmetric distribution design of the flow channel can improve the cooling effect of the liquid cooling system of the battery module, further improve the consistency of the battery temperature, and prolong the cycle life of the power battery. Cooling effect is not strong problem.

The technical problem solved by the present invention adopts the following technical solutions to realize:

A curved variable structure cooling plate applied to a power battery module, installed on both sides of the power battery module to perform liquid cooling or heat conduction preheating for the power battery module, comprising two flow channels arranged in parallel, the The flow channel structure and size are the same, all of which are continuous curved structure flow channels, and the cross-sectional area of the flow channel changes gradually along the flow direction of the heat transfer fluid in the flow channel. The two flow channels are distributed on the center line of the cooling plate. At the same time, the two ends of the cooling plate corresponding to the position of the flow channel are also provided with outer end guide ports for the input and output of the thermal fluid.

With the above structure, when the heat transfer fluid flows through the entire cooling plate along the flow channel with a gradual change in the cross section of the flow channel, the heat transfer capacity of the cooling plate caused by the temperature rise of the heat transfer fluid in the traditional curved flow channel can be greatly improved, and the cooling effect of the battery module is not good. In the best case, the heat exchange capacity of each part of the battery cooling plate can be better balanced, and the temperature difference between the battery cells can be reduced.

As a further limitation, the heat transfer fluid may be a preheated hot heat transfer fluid or a cold heat transfer fluid, that is, the cooling plate can be used for cooling and heat dissipation when the battery temperature is too high, or for preheating when the temperature is too low. hot.

As a further limitation, the flow channels are distributed asymmetrically to reduce the temperature difference between the individual cells and further improve the temperature uniformity of the battery module.

As a further limitation, the cross-section of the flow channel is a rectangular cross-section with a variable aspect ratio, and the variable-section rectangular cross-section flow channel can make the heat exchange capacity of each part of the cooling plate more uniform and the temperature difference smaller.

As a further limitation, in the unequal gradient section of the flow channel, the gradient value of the flow channel section at the center of the battery is larger than the value at both ends. This section change fully takes into account the high center temperature of the single battery when the heat is released. phenomenon, and thus more in line with the actual cooling requirements.

A power battery module with a liquid cooling component includes a power battery module and a cooling component, the power battery module includes a plurality of battery cells arranged in parallel, and there are gaps between the battery cells and adjacent to each other. The distances between the battery cells are equal, the battery cells are packaged and fixed by a battery mounting plate, and a battery module is formed in series or in parallel through bus bars at the pole tabs of the battery cells; and the cooling assembly is installed On both sides of the battery mounting plate of the power battery module, there are insulating heat-conducting sheets and a curvilinear variable-structure cooling plate with the above-mentioned structural features. Fitted on both sides.

As a further limitation, the battery cell preferably adopts a square power lithium battery, so as to facilitate the fit of the insulating and heat-conducting sheet on both sides of the battery, and ensure good thermal conductivity and ease of installation.

As a further limitation, the cooling plate can be detachably replaced by means of plugging and unplugging.

As a further limitation, the battery mounting plate is provided with a plug-in connector for connecting and fixing the cooling plate of the curved deformation structure, so as to realize the fixing of the outer end of the battery module and facilitate the plug-and-replacement of the cooling plate.

Beneficial effects: The curved variable structure cooling plate disclosed by the present invention has a novel structure and an ingenious design. The structure is redesigned on the basis of the original curved flow channel, and two curved asymmetric flow channels are set. This cooling plate structure can make the battery The working temperature of the module is stably controlled within 20 to 45 °C for a long time, and the temperature difference is stable between 2 to 3 °C, which improves the cooling effect of the liquid cooling system of the battery module and the consistency of the battery temperature, which is conducive to prolonging the battery pack. At the same time, through the replacement of thermal fluid, it can realize the heat dissipation of the battery module under complex working conditions and the preheating of the battery in cold weather, reduce the number of parts and components of new energy vehicles, and simplify the control logic.

Description of drawings

FIG. 1 is an assembly schematic diagram of a preferred embodiment of a power battery module with a liquid cooling component of the present invention.

FIG. 2 is an exploded view of the components of the preferred embodiment of FIG. 1 .

FIG. 3 is a schematic diagram of the contour curve of the center line of the cooling plate flow channel according to the preferred embodiment of the present invention.

4 is a schematic cross-sectional view of the interior of the cooling plate according to the preferred embodiment of the present invention.

Wherein: 1. The first cooling plate; 2. The second cooling plate; 3. The first insulating heat-conducting sheet; 4. The second insulating and heat-conducting sheet; 5. The battery mounting plate; 6. The bus bar; 7. The battery cell; 8 , liquid inlet diversion port; 9, liquid outlet diversion port.

Detailed ways

In order to make the technical means, creation features, achievement goals and effects of the present invention easy to understand and understand, the present invention will be further described below with reference to specific illustrations and embodiments.

In the following examples, those skilled in the art will understand that unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art and, unless defined as herein, are not to be taken in an idealized or overly formal sense. explain.

Referring to the embodiment of a power battery module with a liquid cooling component in FIG. 1 and FIG. 2, in this embodiment, the power battery module includes five battery cells 7, a first insulating heat-conducting sheet 3, a second insulating The thermal conductive sheet 4, the first cooling plate 1, the second cooling plate 2, the bus bar 6 and the battery mounting plate 5; the relevant size parameters are:

The simplified size of the battery cells is 120mm×66mm×18mm, and the spacing between the battery cells is 5mm. The size of the cooling plate is 120mm x 110mm x 4mm, the thickness of the flow channel is 2mm, the length of the channel section is 8mm at the inlet and 15mm at the outlet.

The battery cell 7 adopts a square power lithium battery, such as lithium iron phosphate, ternary and so on. The bus bar 6 is mainly a carrier of current, and is made of copper, nickel-plated copper or aluminum and other conductive metals. In this embodiment, the bus bar 6 is a copper bar; the first insulating and heat-conducting sheet 3 and the second insulating and heat-conducting sheet 4 require Good thermal conductivity, light weight, softness, insulation and good moisture-proof effect are made of silicone sheet material; the materials of the first cooling plate 1 and the second cooling plate 2 require good thermal conductivity, light weight, high strength, and good toughness aluminum alloy Made of materials; the thermal fluid adopts a 50% water-50% ethylene glycol mixed solution with high thermal conductivity.

A gap of the same distance is left between the five battery cells 7 for natural air convection. The tabs of the battery cells 7 are connected into groups by the bus bar 6, and are packaged in the battery mounting plate 5 and installed in the first cooling system. Between plate 1 and second cooling plate 2.

The first insulating and heat-conducting sheet 3 and the second insulating and heat-conducting sheet 4 are installed on both sides of the battery module 7 respectively between the first cooling plate 1 and the second cooling plate 2 and the battery module 7, and the three are closely attached to each other. In order to isolate the battery cells 7 from the first cooling plate 1 and the second cooling plate 2, the effects of insulation and moisture resistance are achieved.

The battery mounting plate 5 is installed on the outer end of the battery module composed of the battery cells 7, which improves the sealing performance of the battery module, ensures that the battery module is fastened, and makes the battery module and the cooling plate have a better fit effect, improving the At the same time, a plug opening is provided at the outer end of the battery mounting plate 5 so that the first cooling plate 1 and the second cooling plate 2 can be plugged and replaced better. The externally input heat transfer liquid is introduced from the liquid inlet to the cooling plate flow channel through the flow guide 8, and then flows to the liquid outlet guide port 9 through the cooling plate flow channel to complete the heat exchange for the entire cooling plate and balance the various parts of the cooling plate. heat transfer capacity.

When the power battery module of this embodiment is working, the heat generated by the battery cells 7 is taken away by the natural convection of air between the cell gaps and the circulating liquid cooling system, thereby reducing the temperature and temperature difference of the battery module and controlling the battery The module works within a certain temperature range to improve the consistency of battery temperature and effectively improve the life of the battery pack.

Figure 3 and Figure 4 show the internal cross-sectional views of the cooling plate. The two curved variable-structure flow channels are distributed asymmetrically up and down along the center line of the cooling plate, where a, b, c, d, and e represent the points on the flow channel contour line, respectively. , where the curves f and g represent the contour lines corresponding to the runners, that is, the lines connecting the center points of the cross-sections of the inlet and outlet of the runners, all fall on the centerlines of the respective half-planes. The center line of the flow channel is formed by outlining five curved channel vertices and connecting them with a non-uniform rational basis spline structure, where the vertices corresponding to point a and point e are the center points of the rectangular flow channel section at the inlet and outlet, respectively. , the vertex of point c is on the vertical centerline of the cooling plate, and the vertexes of points b and d are symmetrical about the vertical centerline. In addition, the variable structure of the cooling plate runner section is designed to have a rectangular aspect ratio of unequal gradient, wherein the gradient of the curve peak corresponding to the vertex of point b and point d is 2mm, and the gradient value of the curve valley corresponding to the vertex of point c is 3mm , which is more in line with the actual cooling needs of the battery.

In the embodiment, after a curved variable structure flow channel is obtained by cutting and lofting, another asymmetrical curved variable structure flow channel can be obtained through a linear array.

In the internal cross-sectional view of the cooling plate shown in FIG. 4 , two curved asymmetric variable-structure flow channels are distributed up and down along the centerline of the cooling plate, and the cross-section of the flow channels is a rectangular cross-section. In addition, during the variable structure design of the runner, the width of the rectangular section remains unchanged, and only the length of the runner section is changed to control the aspect ratio of the runner section, and the aspect ratio is controlled within the optimal cooling effect range.

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 by the above-mentioned embodiments, and the descriptions in the above-mentioned embodiments and the description are only to illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have Various changes and modifications fall within the scope of the claimed invention. The claimed scope of the present invention is defined by the appended claims and their equivalents.

Claims (10)

1. A curve type variable structure cooling plate applied to a power battery module is characterized by comprising two runners which are arranged in parallel, wherein the runners are continuous curve structure runners with consistent structures and sizes, the cross-sectional areas of the runners are changed in a non-equal gradual change mode along the flowing direction of heat conducting liquid in the runners, and the two runners are distributed on the upper portion and the lower portion of the center line of the cooling plate; and the two ends of the cooling plate corresponding to the flow passage are respectively provided with an outer end flow guide port for inputting and outputting heat-conducting liquid.

2. The curved variable-structure cooling plate applied to the power battery module as claimed in claim 1, wherein the heat conducting liquid is a heat conducting liquid for cooling and heat dissipation when the temperature of the battery is too high or a heat conducting liquid for preheating when the temperature of the battery is too low.

3. The curved variable structure cooling plate applied to the power battery module as claimed in claim 1, wherein the flow channels are distributed asymmetrically.

4. The curved variable-structure cooling plate applied to the power battery module as claimed in claim 1, wherein the flow channel section is a rectangular section with a variable length-width ratio.

5. The cooling plate with the curved variable structure applied to the power battery module as claimed in claim 1, wherein in the non-uniform and gradually-changed cross section of the flow channel, the gradually-changed value of the cross section of the flow channel at the central part of the battery is greater than the values at the two ends of the battery.

6. A power battery module with a liquid cooling component is characterized in that a curve type variable structure cooling plate applied to the power battery module and provided with any one of claims 1-5 is used as a cooling plate, the power battery module comprises the power battery module and the cooling component, the power battery module comprises a plurality of battery monomers which are arranged in parallel, gaps are reserved among the battery monomers, the intervals among the adjacent battery monomers are equal, the battery monomers are packaged and fixed through a battery mounting plate, and the battery module is formed at the lug positions of the battery monomers in a serial or parallel mode through a busbar; the cooling assembly is arranged on two sides of the battery mounting plate of the power battery module and comprises insulating heat-conducting fins and a cooling plate, and the insulating heat-conducting fins are abutted against the inner side of the cooling plate and are attached to the side faces of two sides of the battery module.

7. The curved variable structure cooling plate applied to the power battery module as claimed in claim 6, wherein the battery cells are square power lithium batteries.

8. The cooling plate with the curved variable structure applied to the power battery module as claimed in claim 6, wherein the cooling plate is detachably replaced by plugging.

9. The cooling plate with the curved variable structure applied to the power battery module as claimed in claim 6, wherein the battery mounting plate is provided with a plug-in connector for fixedly connecting the cooling plate with the curved variable structure.

10. The curved variable-structure cooling plate applied to the power battery module as claimed in claim 6, wherein the bus bar is formed by copper, copper nickel plating or aluminum molding.

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