CN205646065U - Air -cooled power battery heat abstractor - Google Patents

Abstract

The utility model provides an air -cooled power battery heat abstractor, interval arrangement a plurality of cylindricality battery in the ascending battery of the opening package box, an at least thermal diffusion plate of configuration in the battery package box between battery top and bottom, the thermal diffusion plate passes through the inseparable overcoat of sleeve on the battery, the space is left with battery package box both sides lateral wall in the thermal diffusion plate both ends, sets up air intake and air exit on the lateral wall of above -mentioned both sides respectively to, dispose the fan on air intake and/or the air exit, set up or do not set up the ventilation hole on the thermal diffusion plate, if offer the ventilation hole, the battery package box space of below on the intercommunication thermal diffusion plate of ventilation hole. This device radiating effect is good, and the distribution of temperature is more even, and the appearance is compact, and simple structure is applicable to power battery system.

Description

An air-cooled power battery cooling device

technical field

The utility model relates to the technical field of power battery cooling, in particular to an air-cooled power battery cooling device.

Background technique

Power batteries such as lithium-ion batteries have high energy density, small size, and long cycle life. They have great potential for application in electric passenger cars and commercial vehicles. However, since the temperature rise of the lithium-ion battery during charging and discharging affects its performance and cycle life, too high temperature may even cause thermal runaway, resulting in accidents such as spontaneous combustion and explosion. The temperature of the conventional lithium cobaltate cathode material battery needs to be controlled at 50 degrees Celsius. Within, to avoid thermal runaway and fire explosion, improve safety. With the advancement of battery materials and processes, although the operating temperature of batteries using lithium iron phosphate as the positive electrode material can be raised to 60 degrees Celsius or higher, as the temperature rises further, the battery capacity decays significantly, and thermal runaway will still occur at high temperatures and fire phenomena. Therefore, the research and implementation of power lithium-ion battery heat dissipation technology is particularly urgent.

The power lithium-ion battery heat dissipation system usually adopts air cooling to cool the battery channel. The conventional air cooling heat dissipation system is small in size, but the heat dissipation effect is limited, and the battery temperature uniformity is poor. The use of latent heat absorption of phase change materials is another battery thermal management method. Phase change materials such as paraffin materials have the advantages of high latent heat absorption during the phase change process, small temperature rise, good chemical stability, small size, simple structure, and low price. Applied to power lithium-ion batteries, it can reduce the temperature rise rate of the battery, alleviate thermal shock, and improve battery life and stability. However, phase change materials also have disadvantages such as low thermal conductivity and inability to conduct heat quickly and uniformly.

Patent 201210399617.6 discloses a battery module comprising: a plurality of prismatic battery cells; and corrugated fins defining a generally meandering shape, the corrugated fins have alternating straight segments and top segments, such that the multiple groups At least one of the battery cells is disposed in a region of the corrugated fin defined between adjacent straight segments. Although this patent has a certain heat dissipation effect, there is no special fastening mechanism for heat transfer from the power battery to the fins, resulting in large contact gaps and contact thermal resistance, and a large temperature difference in heat transfer from the center to the outside, which is not suitable for high-power power. type battery.

Patent 200910039125.4 discloses a power battery device with a phase change material cooling system, which includes screws, several battery cells, vent holes in the case cover, electrode connecting shafts, top cover of the case body, side vent holes, and a frame; The above-mentioned battery cell uses the battery as the base body, and a shell is installed on the outside; the phase change material is filled between the battery and the shell and sealed with insulating rubber; the battery box is provided with ventilation holes for heat dissipation. Although the patent alleviates the thermal impact of the battery by filling the phase change material, it does not solve the shortcomings of slow heat dissipation and insufficient temperature control caused by the low thermal conductivity of the phase change material. When the phase change material is completely melted, the latent heat absorption ends, and the low thermal conductivity actually blocks the heat dissipation speed to the battery case.

Patent 201110345442.6 discloses a solar flower radiator for LED lamps, which includes a circular heat sink and a number of heat sink fins. The heat sink fins are arranged on the outer circle of the circular heat sink. It is characterized in that it also includes heat sink ribs. A heat dissipation rib is connected between two adjacent heat dissipation fins, and the heat dissipation rib is arc-shaped. The heat sink is made of copper material. The heat dissipation fins of this patent are prepared by an extrusion process, which is relatively complicated and time-consuming, and the heat dissipation fins produced are too heavy and bulky, and cannot be used for power plants that require high weight and volume, such as automobiles. battery system.

Utility model content

The technical problem to be solved by the utility model is to provide an air-cooled power battery cooling device. The device forms an excellent heat conduction path through a thermal diffusion plate, and is equipped with a fan to form an active cooling method of forced convection. On the one hand, it improves the heat dissipation speed and reduces the maximum Temperature, on the other hand, the battery has good temperature uniformity during use, and the device has a compact structure and a relatively small volume, which is conducive to arrangement in a limited space.

The utility model is achieved through the following technical solutions:

An air-cooled power battery cooling device, characterized in that:

Several cylindrical batteries are arranged at intervals in the battery pack box with the opening upward, and at least one thermal diffusion plate is arranged in the battery pack box between the top and bottom of the battery. The thermal diffusion plate is provided with through holes corresponding to the batteries, and the inner edge of the through hole is Tightly cover the battery through the sleeve;

There are gaps between the two ends of the thermal diffusion plate and the side walls on both sides of the battery pack box, and air inlets and air outlets are respectively set on the side walls on both sides, and fans are arranged on the air inlets and/or air outlets to heat the air. Ventilation holes may or may not be provided on the diffuser plate. If ventilated holes are provided, the vent holes are connected to the space of the battery pack box below the thermal diffuser plate.

The battery pack box has an air inlet and an air outlet, and several fans are arranged on the air inlet and/or the air outlet to form an active air-cooled heat dissipation structure with forced convection; on the one hand, the thermal diffusion plate can increase the convective heat transfer area, thereby Reduce the maximum temperature difference. On the other hand, the thermal diffusion plate is generally made of materials with high thermal conductivity such as aluminum, copper, titanium, etc., which have reverse thermal conductivity, thereby reducing the temperature difference between the upstream and downstream of the battery and improving the temperature uniformity of the battery. The inner edge of the through hole on the thermal diffusion plate is formed by a stamping process or other processing methods to form a sleeve structure, which can increase the heat conduction area between the thermal diffusion plate and the battery, improve mechanical stability and heat conduction efficiency; the thermal diffusion plate can be opened A number of ventilation holes reduce wind resistance and balance the air volume on the upper and lower sides of the thermal diffusion plate, thereby further improving fan efficiency and wind speed, and reducing the maximum temperature of the battery.

Further, the through holes are arranged in a fork row or in a row on the heat diffusion plate. This arrangement method not only makes full use of the internal space of the battery pack box, arranges as many batteries as possible in a limited space, and has a compact structure, and the evenly spaced arrangement of the batteries is also conducive to improving the heat dissipation efficiency.

Still further, an interface thermally conductive material layer is filled between the sleeve and the battery; the interface thermally conductive material layer is a thermally conductive bond with polyurethane, silicone, epoxy resin or acrylic as the matrix, and the thermal conductivity is not less than 0.2W/mK glue layer. The interface thermally conductive material layer has two functions: one is to ensure that the thermally conductive contact surface between the sleeve and the battery is sufficient, and to avoid the thermally conductive hollow belt caused by the gap formed in the local area due to processing, assembly, etc., and the other is that the interface thermally conductive material layer can also Play a fixed role to avoid loose contact interface.

Still further, the heat diffusion plate is multi-layer arranged at intervals above and below, so as to increase the heat exchange area and further reduce the temperature rise and temperature gradient of the battery.

Still further, the through hole on the thermal diffusion plate is punched and formed, and the sleeve is a 70-90 degree right angle or nearly right angle folded surface formed on the inner edge of the through hole during punching, and the sleeve can face up or down , The sleeve is naturally formed by turning the four sides into straight sides when the through hole is stamped. The structure is simple and easy to process.

Furthermore, the thermal diffusion plate is a metal plate with high thermal conductivity such as aluminum, copper, titanium, iron, etc., and the thickness is 0.1-5mm; the heat conduction column is a metal cylinder with high thermal conductivity such as aluminum or copper. The material selection of the heat spreading plate and the heat conduction column not only has high heat conduction efficiency, but also is easy to process.

Still further, the thermal diffusion plate is an aluminum plate or an aluminum alloy plate, and its outer surface is covered with an oxide film layer with medium-voltage electrical insulation strength after anodic oxidation passivation treatment. The anodized aluminum or its alloys have improved hardness and wear resistance. The melting point of the hard anodized film is as high as 2320K, the breakdown voltage is as high as 2000V, and it has excellent electrical insulation.

Still further, the fan arranged on the air inlet is a centrifugal blower fan, and the fan arranged on the air outlet is an axial flow exhaust fan, so as to enhance the effect of air convection.

Still further, an upper insulating positioning plate is arranged in the battery pack case, and the upper insulating positioning plate is tightly fitted on the top of the battery and is located above the thermal diffusion plate; the battery pack case is cooled by air or liquid, and the material of the battery case is metal aluminum , and with reinforcing ribs. The ribs not only increase the mechanical strength and impact resistance of the battery pack box, but also increase the surface area of the battery box and accelerate the heat transfer on the surface of the battery pack box.

The beneficial effects of the utility model are:

1. Excellent heat transfer enhancement effect. Due to the limited surface area of the battery and the large thermal resistance, the utility model adopts the thermal diffusion plate and the sleeve made of high thermal conductivity metal materials, which can greatly increase the heat exchange area, strengthen the air-cooled heat exchange, and reduce the heat dissipation thermal resistance of the battery, thereby greatly reducing The maximum temperature of the battery. At the same time, the high thermal conductivity of the thermal diffusion plate also reduces the unevenness of the battery temperature, and has an excellent effect of enhancing heat transfer and temperature uniformity.

2. Good impact buffering effect and low cost: The thermal diffusion plate structure is easy to process, low in cost, has good toughness and lower hardness. In extreme cases such as external impact, it can be bent and deformed by impact, absorbing stress and thus Buffer the impact strength of heat-generating devices;

3. Forced convection enhances the heat dissipation effect. The forced convection air duct is formed by opening air inlets and exhaust outlets to dissipate heat from the thermal diffusion plate and the battery itself, further enhancing the heat dissipation effect.

Description of drawings

Fig. 1 is a schematic diagram of a perspective front view structure of a preferred solution of the device.

Fig. 2 is a sectional view taken along line A-A of Fig. 1 .

Fig. 3 is a sectional view taken along line B-B of Fig. 2 .

4-5 are schematic diagrams of cooperation between two different sleeve structures and the thermal diffusion plate.

Fig. 6 is a cross-sectional view of a heat sink with three layers of thermal diffusion plates.

Figures 7 to 9 show the calculation and simulation results of fan cooling for 18650 cylindrical batteries (18 means diameter, 65 means length, all in mm) in an 8X8 parallel array, where:

Figure 7 Simulation results: the temperature cloud map of the battery without the thermal diffusion plate (unit: ℃);

Figure 8 Simulation results: the temperature cloud diagram of a battery with a thermal diffusion plate installed in the middle of the battery (unit: ℃);

Fig. 9 Simulation results: temperature cloud map (unit: ℃) of the battery with three thermal diffusion plates installed on the upper, middle and lower parts of the battery respectively.

Among them: 1 is the battery, 2 is the thermal diffusion plate, 4 is the ventilation hole, 6 is the fan, 7 is the interface heat conduction material layer, 8 is the sleeve, 9 is the connecting circuit, 10 is the upper insulation positioning plate, 11 is the battery box body side wall.

detailed description

Below in conjunction with accompanying drawing, the utility model is further described.

As shown in Figures 1 to 3 and Figure 6, several cylindrical batteries 1 are vertically arranged at intervals in the battery pack box with the opening upward. Near the top of the battery 1 , an upper insulating plate 10 is disposed in the battery pack box, and the upper insulating positioning plate 10 is tightly sleeved on the battery 1 .

As shown in Figure 6, three thermal diffusion plates 2 are arranged in the battery pack box between the top and bottom of the battery. plate 2. The thermal diffusion plate 2 is a metal plate with high thermal conductivity such as aluminum, copper, titanium, iron, etc., with a thickness of 0.1-5mm. The outer surface of the thermal diffusion plate 2 has an oxide film layer with electrical insulation strength after anodic oxidation passivation treatment. .

As shown in Figures 1 to 3 and Figure 6, there are gaps between the two ends of the thermal diffusion plate 2 and the side walls 11 on both sides of the battery pack box body, and air inlets and air outlets are respectively set on the side walls on both sides, and A fan is arranged on the air inlet and/or the air outlet, and a number of ventilation holes 4 are opened on the thermal diffusion plate 2 to communicate with the space of the battery pack box above and below the thermal diffusion plate 2 .

As shown in FIGS. 4-5 , through holes corresponding to the battery 1 are punched out on the thermal diffusion plate 2 , and the upward and downward 90-degree right-angled surfaces formed on the inner edge of the through hole during punching are the sleeves 8 . The sleeve 8 is tightly sheathed at the middle and upper height positions of the battery 1 . The heat diffusion plate 2 may have a one-way sleeve or a two-way sleeve. One method of forming a two-way sleeve is to bond two heat diffusion plates 2 with the same one-way sleeve in a mirror image.

As shown in Figure 3, the interface thermally conductive material layer 7 is filled between the sleeve 8 and the battery 1, and the interface thermally conductive material layer 7 is based on polyurethane, silicone, epoxy resin or acrylic acid, and the thermal conductivity is not less than 0.2W/mK. Thermally conductive adhesive layer.

As shown in FIGS. 1-3 , several fans 6 are arranged at the air outlet of the battery pack box, with some gaps away from the thermal diffusion plate 2 , which can reduce the backflow effect at the tail end of the thermal diffusion plate 2 . The fan can also be arranged at the air inlet of the battery pack case, wherein it is advisable to arrange the fan 6 at the air outlet of the battery pack case, so as to prevent the cold wind from directly blowing the battery 1 and reduce the temperature unevenness of the battery 1 .

As shown in Figure 6, the positive electrodes of the battery 1 are grouped upwards. In order to further reduce the temperature rise and temperature gradient, multi-layer thermal diffusion plates can be installed, which are respectively located at the lower, middle and upper positions of the battery 1.

As shown in Figures 7 to 9, during the computer numerical simulation process, the material of the thermal diffusion plate 2 and the bottom 6 of the battery pack box are all aluminum alloy 6063, the thickness of the thermal diffusion plate 2 is 1.8mm, and the battery model is 18650 lithium battery (where 18 means the diameter is 18mm, 65 means the length is 65mm, and 0 means cylindrical battery), the heating power simulates the heating condition under ordinary rate discharge, the heating value is 1W, and the air temperature at the air inlet is set at a constant temperature of 30°C.

As shown in Figure 7, when there is no thermal diffusion plate 2, its heat dissipation mainly depends on the forced convection of the battery. Due to the heat capacity effect of the air, the temperature of the air rises with the flow direction, resulting in a large temperature difference between the upstream and downstream of the battery, close to the air outlet The highest temperature is 53°C, and the temperature difference between upstream and downstream batteries exceeds 13°C.

As shown in Figure 8, when the thermal diffusion plate 2 is used, the heat of the battery cells can be directly exchanged to the air through the extended surface of the thermal diffusion plate, thereby reducing the thermal resistance of the battery and avoiding excessive battery temperature. At the same time, due to the heat conduction effect of the thermal diffusion plate 2, the temperature uniformity of the battery is good, which avoids the rapid attenuation of the capacity of some batteries caused by the temperature gradient, thereby improving the overall life and service life of the battery. When three thermal diffusion plates are used, the maximum temperature of the battery is further reduced, and the temperature difference between the batteries is further reduced, as shown in Fig. 9 .

Claims (8)

1. An air-cooled power battery cooling device, characterized in that: A number of cylindrical batteries (1) are arranged at intervals in the battery pack box with the opening upward, and at least one thermal diffusion plate (2) is arranged in the battery pack box between the top and bottom of the battery. (1) The corresponding through hole, the inner edge of the through hole is tightly covered on the battery (1) through the sleeve (8); There are gaps between the two ends of the thermal diffusion plate (2) and the side walls (11) on both sides of the battery pack box body, and an air inlet and an air outlet are respectively set on the side walls on both sides, and the air inlet and/or the air outlet A fan is arranged on the tuyere, and the ventilation hole (4) is provided or not provided on the thermal diffusion plate (2). If the ventilation hole (4) is provided, the ventilation hole (4) is connected to the space of the battery pack box above and below the thermal diffusion plate (2) . 2. The air-cooled power battery cooling device according to claim 1, characterized in that: the through holes are arranged in a fork or in a row on the thermal diffusion plate (2). 3. The air-cooled power battery cooling device according to claim 1, characterized in that: An interface thermally conductive material layer (7) is filled between the sleeve (8) and the battery (1); The interface thermally conductive material layer (7) is a thermally conductive adhesive layer with a matrix of polyurethane, silicone, epoxy resin or acrylic, and a thermal conductivity of not less than 0.2W/mK. 4. The air-cooled power battery cooling device according to claim 1, characterized in that: the through hole on the thermal diffusion plate (2) is formed by stamping, and the sleeve (8) is in the through hole when stamping The 70-90 degree turning surface formed by the edge. 5. The air-cooled power battery cooling device according to claim 1, characterized in that: the thermal diffusion plate (2) is a high thermal conductivity metal plate with a thickness of 0.1-5 mm. 6. The air-cooled power battery cooling device according to claim 1, characterized in that: the thermal diffusion plate (2) is an aluminum plate or an aluminum alloy plate, and its outer surface is covered with a layer after anodic oxidation passivation treatment, Oxide film layer with medium voltage electrical insulation strength. 7. The air-cooled power battery cooling device according to claim 1, wherein the fan disposed on the air inlet is a centrifugal blower fan, and the fan disposed on the air exhaust port is an axial flow exhaust fan. 8. The air-cooled power battery cooling device according to claim 1, characterized in that: The upper insulating positioning plate (10) is arranged in the battery pack box, and the upper insulating positioning plate (10) is tightly sleeved on the top of the battery (1) and located above the thermal diffusion plate (2); the battery pack box is cooled by air or liquid Cooling, the material of the battery box is metal aluminum with reinforcing ribs.