蜘蛛网流道冷板冷却液对向流锂离子电池散热分析

Analysis of Lithium-ion Battery Heat Dissipation with Coolant Counter Current in Spider Web Channel Cooling Plate

锂离子电池工作温度过高或温差过大将导致其容量降低和寿命缩短。为了降低其工作温度及温差,设计了一款蜘蛛网流道冷板,采用数值方法对其冷却液对向流锂离子电池散热进行了计算。比较了蜘蛛网流道冷板冷却液对向流与同向流锂离子电池的散热情况,分析了冷却液流量以及冷板内流道夹角、槽深、壁厚对电池散热的影响。结果表明:与冷却液同向流电池相比,冷却液对向流电池最高温度、温差都降低,电池温度分布更加均匀。在0.02~0.06 kg/s区间,随着冷却液流量增大,电池最高温度和温差快速降低,而冷却液压降缓慢增大;当冷却液流量大于0.06 kg/s时,随着冷却液流量增大,电池最高温度和温差缓慢降低,而冷却液压降快速增大。增大流道夹角可使流道在冷板内分布更加均匀,提高冷板散热能力。当冷却液质量流量恒定时,增大流道槽深可使冷却液压降显著减小,但会引起电池最高温度和温差略微升高。随着流道壁厚增大,电池最高温度和温差均呈下降趋势。蜘蛛网流道冷板在流道夹角80°、槽深1 mm、壁厚2 mm、冷却液流量0.06 kg/s对向流冷却条件下,可使锂离子电池3C放电最高温度和温差降至31.02℃和4.54℃。

High operating temperature or large temperature difference of lithium-ion battery will reduce its capacity and lifetime.In order to reduce the operating temperature and temperature difference,a spider web channel cooling plate was designed.And the heat dissipation of lithium-ion battery was calculated with the coolant counter current in the channel of the cooling plate by numerical method.The heat dissipation of lithium-ion battery with the coolant in counter current was compared with its heat dissipation with the coolant in co-current.And the effects of flow rate,channel angle,groove depth and wall thickness on the battery heat dissipation were analyzed.The results show that the maximum temperature and temperature difference of the battery cooled with the coolant in counter current are lower than those with the coolant in co-current,and the tempe-rature distribution of the battery is more uniform.In the range of 0.02—0.06 kg/s,with the increase of coolant flow rate,the maximum temperature and temperature difference of the battery decrease rapidly,while the cooling hydraulic drop increases slowly.However,when the coolant flow rate is greater than 0.06 kg/s,with the increase of coolant flow rate,the maximum temperature and temperature difference of the battery decrease slowly,while the cooling hydraulic drop increases rapidly.Increasing the channel angle can make the channel distribution more uniform in the cooling plate and improve the cooling capacity of the cooling plate.Under the condition of the constant of the mass flow rate of coolant,increasing the channel groove depth can greatly reduce the cooling hydraulic drop,but it will cause the maximum temperature and temperature difference of the battery to increase slightly.With the increase of the wall thickness of the flow channel,the maximum temperature and temperature difference of the battery show a downward trend.The maximum temperature and temperature difference of 3C discharge of lithium-ion battery can be reduced to 31.02℃and 4.54℃under the conditions of channel angle 80°,groove depth 1 mm,wall thickness 2 mm and coolant flow rate 0.06 kg/s.