纯电动汽车电池箱的热特性

首先利用实验和计算求得纯电动汽车动力电池的热物性参数,然后通过ANSYS有限元仿真软件,对电池组生热和散热温度场进行仿真分析,完成了电池组的散热系统设计;通过对电池箱加热和保温结构进行仿真分析,完成了加热设计和保温设计。最后,通过实验验证了电池箱散热、加热和保温设计的有效性。     

相变材料/导热翅片复合热管理系统应用于三元体系锂离子动力电池模组实验研究

以三元动力电池模组为研究对象,通过研究自然对流、相变材料（Phase Change Materials,PCM）、相变材料/导热翅片3种不同散热技术,分析3种不同热管理系统（Battery Thermal Management System,BTMS）在室温（25℃）和高温（45℃）工况下不同恒定倍率放电及充放电循环过程中的温度变化规律、产热速率及温升速率,测试整个电化学反应进程中的最大温度及最大温差技术指标,深入研究不同散热介质对于电池组安全性能的影响机理。结果表明,无论室温/高温环境条件恒定倍率放电和大电流充放电循环工况,相变材料/导热翅片电池组通过对电池组侧面和正负极处进行强化传热,具有明显有效的降温和均衡温度的能力,可以实现电池组最高温度的快速降低,并维持电池模组最高温差在5℃以内,满足动力电池模组的散热需求。     

基于Ansys Workbench12.0的磷酸铁锂动力电池温度场特性研究

针对电动汽车用磷酸铁锂动力电池温度场分布的均匀性问题,本文以某厂家生产的磷酸铁锂电池IFP36230218为例,依据仿真计算所涉及的理论,基于Ansys Work-bench 12.0软件,提出了一种通用的仿真计算过程,并分别对电池单体及模块在不同冷却条件下的温度场特性进行仿真研究,仿真结果表明,散热情况越好,电池内部温度的一致性就越好,电池寿命和稳定性越高。该研究为实际工程中测定电池温度场分布和设计、优化电池组热管理系统提供了理论依据。     

电动汽车锂离子电池散热加热设计

锂离子电池热管理已成为制约电动汽车商业化的瓶颈,为解决此问题,将微热管阵列应用于锂离子电池散热和加热系统.通过测量布置热管前后电池表面温度可知:在1C充放电倍率下,散热系统能有效降低电池模组的温度及电池间温度差异,将温度和温度差值分别控制在40℃与5℃之内;通过加热片加热热管,有效提高电池低温放电性能,从而提高电池持续充放电过程的稳定性和安全性.     

基于多物理场耦合的动力电池组热性能分析

为使某自主品牌电动汽车动力电池的热管理性能满足设计和安全要求,通过实验标定单体电池生热参数,对单体电池进行基于不同变量的热流实时耦合仿真,找到各变量对散热性能贡献度。调控风冷系统参数,通过热流实时耦合仿真考察此时电池热管理性能。结果表明:1C放电率下,当冷却空气温度为6℃,流速为13.6m~3/h时,电池热管理性能满足安全要求且在实际路试中散热性表现良好。此分析方法可有效指导动力电池的开发,对正向设计具备一定参考意义。     

车用动力电池模组风冷散热分析

为了降低车用动力电池模组的最高温度、提高其温度分布一致性,以4×8等间距排列18650锂离子电池模组为分析对象,运用ANSYS Fluent软件对圆形进风口,圆形、半圆形及矩形出风口三种不同散热结构及尺寸电池模组温度场进行了计算。结果表明:矩形出风口散热结构电池模组的最高温度和温度变异系数比相同工况下圆形与半圆形出风口散热结构都小。当进口风速为1~3m/s,矩形出风口为40mm×50mm时,电池模组的最高温度和温度变异系数最小;当进口风速3m/s、矩形出风口为40mm×70mm时,电池模组的最高温度和温度变异系数最小。     

圆柱电池模组的热电制冷与温控性能分析

基于帕尔贴效应提出一种通过热电装置（Thermoelectric Device,TED）实时控制电池温度的方法.该方法集TED的制冷与加热功能于一体，控温效果良好，可以满足电池模组热管理需求.电池模组由3×5排列的圆柱电池组成，填充泡沫金属复合相变材料，热电装置布置在电池模组外壳正对大面处.与液冷试验相比，热电制冷可以在1～5 W单电池产热功率下显著降低电池模组的温度，将模组温差控制在5℃内.温控试验进一步表明，采用温控器实时控制的TED可以有效稳定模组温度，将温度波动控制在2～3℃.此外，建立一维热阻网络，基于稳态理论对TED热性能分析.结果表明，在制冷工况下，TED的冷端温度随其电流的增大呈先减后增的趋势，热端温度与TED电流成正比.     

液冷系统中冷板的设计及网络建模优化研究

通过分析现有散热系统的优缺点,设计了一种S型通道冷板和多支路并联的液冷系统,以使芯片数量多、位置分散、功率各不相同且对空间尺寸要求严格的电子设备满足均衡有效散热的需求。利用Fluent软件对S型通道冷板进行换热和流动特性数值分析,利用MacroFlow软件对整个液冷系统进行流体网络模拟和加阻优化分析。仿真结果表明,优化后的液冷系统能够使分散式散热的电子元器件实现有效散热。     

基于微通道液冷板的动力电池热管理性能分析

为了保证锂离子动力电池的安全性能并延长电池的循环使用寿命,设计了一种基于微通道液冷板的电池热管理系统,对锂离子棱柱形电池进行冷却。建立了电池冷却系统的三维热模型,研究高放电倍率、冷却液温度和进口质量流量对电池放电过程中最高温度和最大温差的影响。结果表明：锂离子电池组在5C高倍率放电工况下,电池最高温度为301.942 K,温差为1.942 K,达到预期冷却效果;随着冷却液温度降低和进口质量流量增加,电池最高温度降低;随着进口质量流量增加,电池冷却性能改善,但趋势逐渐变小。当冷却液温度为296 K时,电池最高温度为297.662 K;当质量流量为15×10-7 kg/s时,温差为4.407 K。     

动力电池组扁管束液流热管理增效

针对电动汽车动力电池组热管理需求,设计了一种扁管束叠层液流换热结构,并通过CFD计算对比分析了添加高导热石墨膜前、后电池组冷却过程中的温变性、温度一致性和温均性等。仿真计算结果表明:未添加石墨前电池片间扁管束和单片电池表面扁管间换热一致性较好,但相同电池片上不同特征点间温度差异较大;此外,电池表面铺垫柔性石墨后电池温降速率明显增大,同时单片电池温均性得到显著提升。这表明本文设计的管束叠层液流换热结构能够保障电池组较佳的热管理效果,与整板式液体换热电池包相比进一步实现了轻量化。     

导热硅胶/相变材料复合组件在电池热管理中的应用

一种低温导热硅胶/相变材料复合组件在电池模组中的使用,有效地解决了相变材料由于液化而发生的析出问题,同时保持相变材料高导热与高潜热值.由于导热硅胶片具有一定的弹性与黏性,使得整个系统具有一定缓冲作用,减少了相变材料与电池之间的接触热阻,进一步提高了整个系统的散热性能.在3C放电倍率下,相比自然冷却方式的66.63 ℃,...     

Design and parametric optimization of thermal management of lithium-ion battery module with reciprocating air-flow

Single cell temperature difference of lithium-ion battery(LIB) module will significantly affect the safety and cycle life of the battery. The reciprocating air-flow module created by a periodic reversal of the air flow was investigated in an effort to mitigate the inherent temperature gradient problem of the conventional battery system with a unidirectional coolant flow with computational fluid dynamics(CFD). Orthogonal experiment and optimization design method based on computational fluid dynamics virtual experiments were developed. A set of optimized design factors for the cooling of reciprocating air flow of LIB thermal management was determined. The simulation experiments show that the reciprocating flow can achieve good heat dissipation, reduce the temperature difference, improve the temperature homogeneity and effectively lower the maximal temperature of the modular battery. The reciprocating flow improves the safety, long-term performance and life span of LIB.     

新型管状相变材料热管理系统的数值仿真与实验研究

设计了一种新型的管状复合相变材料(tubular Composite PCM,t-CPCM)结构,用以替代传统的块状复合相变材料(block-shaped Composite PCM,b-CPCM)结构,将其耦合强制对流换热后应用于电池热管理。仿真结果表明,相比于b-CPCM电池仿真模型,t-CPCM电池仿真模型不仅流道分布更加均匀,而且对流换热面积更大,理论计算得出的对流换热热阻仅为0.8 K·W⁻¹,是b-CPCM电池仿真模型的1/20。实验结果表明,t-CPCM电池模组优异的散热性能可以有效地控制电池温度,t-CPCM电池模组的最高温度仅为46.9 ℃,温差为0.8 ℃;而b-CPCM电池模组的最高温度高达51 ℃,温差均为5 ℃。所设计的管状复合相变材料在电池热管理方面具有良好的应用价值。     

基于CFD分析的电动汽车电池包加热方法

锂离子电池对温度环境要求严苛,在低温下常出现失效、寿命衰退等现象. 因此,为电池包设计高效、均匀且节能的加热方案,成为电动汽车在北方环境下发展的关键. 引入计算流体动力学（CFD）的仿真计算方法,并采用多孔介质理论对电池包中电池模块进行简化分析,对电动汽车电池包在加热过程中的温升特性进行仿真分析计算,将仿真计算结果与实测数据进行对比验证,证明所采用的仿真方法及多孔介质简化模型可有效应用于电动汽车电池包的加热方案评估. 根据分析结果对加热方案提出修正,并设计分块化的加热方案,即对局部加热功率进行控制. 计算结果显示,优化后的分块加热方案,在总体功率降低167 W（约7%）的情况下,仍然可在50 min内将电池包从?13 °C加热到5 °C,并且将电池包中电池区域最大温差控制在5 °C以内.     

电动汽车电池热管理系统设计与分析

针对高功率、高比能的动力电池散热问题,提出结构紧凑、换热高效的制冷剂直接热传输的电池热管理系统（简称直冷式系统）. 以整车系统为背景,利用AMESim搭建空调制冷与电池热管理的耦合模型,从系统的温度响应和能耗角度,分析电池组及电池单体平均温降、温均、系统COP以及?效率. 结果表明,直冷式系统具有较快的温度响应特性,在高温高速的稳态和动态工况下都可以对电池进行快速降温,实现了较好的温均性. 在针对某一稳定工况进行能耗分析时,得出COP为4.19的较高的系统能效比,但系统的?效率为46.17%,存在进一步提升系统?效率的空间.     

Electrically driven chip cooling device using hybrid coolants of liquid metal and aqueous solution

Heat dissipation of electronic devices keeps as a tough issue for decades. As the most classical coolant in a convective heat transfer process, water has been widely adopted which however inherits with limited thermal conductivity and relies heavily on mechanical pump. As an alternative, the room temperature liquid metal was increasingly emerging as an important coolant to realize much stronger enhanced heat transfer. However, its thermal capacity is somewhat lower than that of water, which may restrict the overall cooling performance. In addition, the high cost by taking too much amount of liquid metal into the device also turns out to be a big concern for practical purpose. Here, through combining the individual merits from both the liquid metal with high conductivity and water with large heat capacity, we proposed and demonstrated a new conceptual cooling device that integrated hybrid coolants, radiator and annular channel together for chip thermal management. Particularly, the electrically induced actuation effect of liquid metal was introduced as the only flow driving strategy, which significantly simplified the whole system design. This enables the liquid metal sphere and its surrounding aqueous solution to be quickly accelerated to a large speed under only a very low electric voltage. Further experiments demonstrated that the cooling device could effectively maintain the temperature of a hotpot (3.15 W/cm²) below 55ºC with an extremely small power consumption rate (0.8 W). Several situations to simulate the practical working of the device were experimentally explored and a theoretical thermal resistance model was established to evaluate its heat transfer performance. The present work suggests an important way to make highly compact chip cooling device, which can be flexibly extended into a wide variety of engineering areas.     

Modeling and Optimization of Heat Dissipation Structure of EV Battery Pack

In order to solve the problems of high temperature and inconsistency in the operation of electric vehicle (EV) battery pack,computational fluid dynamics (CFD) simulation method is used to simulate and optimize the heat dissipation of battery pack.The heat generation rate at different discharge magnifications is identified by establishing the heat generation model of the battery.In the forced air cooling mode,the Fluent software is used to compare the effects of different inlet and outlet directions,inlet angles,outlet angles,outlet sizes and inlet air speeds on heat dissipation.The simulation results show that the heat dissipation effect of the structure with the inlet and outlet on the same side is better than that on the different sides;the appropriate inlet angle and outlet width can improve the uniformity of temperature field;the increase of the inlet speed can improve the heat dissipation effect significantly.Compared with the steady temperature field of the initial structure,the average temperature after structure optimization is reduced by 4.8℃ and the temperature difference is reduced by 15.8℃,so that the battery can work under reasonable temperature and temperature difference.     

Modeling and Optimization of Heat Dissipation Structure of EV Battery Pack

In order to solve the problems of high temperature and inconsistency in the operation of electric vehicle (EV) battery pack,computational fluid dynamics (CFD) simulation method is used to simulate and optimize the heat dissipation of battery pack.The heat generation rate at different discharge magnifications is identified by establishing the heat generation model of the battery.In the forced air cooling mode,the Fluent software is used to compare the effects of different inlet and out-let directions,inlet angles,outlet angles,outlet sizes and inlet air speeds on heat dissipation.The simulation results show that the heat dissipation effect of the structure with the inlet and outlet on the same side is better than that on the different sides;the appropriate inlet angle and outlet width can improve the uniformity of temperature field;the increase of the inlet speed can improve the heat dissipation effect significantly.Compared with the steady temperature field of the initial structure, the average temperature after structure optimization is reduced by 4.8益and the temperature difference is reduced by 15.8℃,so that the battery can work under reasonable temperature and temperature difference.