混合动力公交客车锂离子动力电池舱的热特性研究

发布时间：2018-05-04 18:46

本文选题：混合动力公交客车 + 磷酸铁锂电池　；参考：《华南理工大学》2014年硕士论文

【摘要】：由于具有良好的充放电性能和安全性能，锂离子动力电池已在混合动力电动公交客车（Hybrid Electric Bus，HEB）上得到了广泛地应用。针对在广州市公交行驶工况条件下，HEB锂离子动力电池出现的工作温度差异大、电池舱产热量大和散热差的难题，以广州某款HEB的磷酸铁锂（LiFePO4/C）动力电池舱为研究对象，以提高电池舱中LiFePO4/C动力电池组的散热性能为目的，采用实验和计算流体动力学（ComputationalFluid Dynamics，CFD）的方法，研究LiFePO4/C动力电池，电池箱及其电池舱的产热及传热特性，提出基于散热性能的电池箱散热结构设计方法。首先，以LiFePO4/C电池单体为对象，通过电池充放电实验和电池热效应的理论分析和计算，研究温度与电池容量，内阻，开路电压与荷电状态的关系，探讨LiFePO4/C动力电池充放电时的产热和传热机理，以及对流换热系数和空气来流温度对电池散热性能的影响。然后，以HEB的LiFePO4/C电池舱为对象，根据流体动力学及传热学理论，研究电池舱内空气的流动与传热原理，建立电池舱及其内部的LiFePO4/C电池箱和电池组的几何模型，，网格模型，以及空气流动与传热数学模型，结合电池舱实车测试实验和电池热特性分析来获取CFD仿真的边界条件。在此基础上，对电池舱内空气流场和LiFePO4/C电池组的温度场进行CFD仿真计算，并分析冷却空气流动和温度分布与电池组散热的关系；以此为向导，提出风道热阻模型，并以此来探讨电池箱内电池散热风道的传热机理。其次，进行了HEB实车测试实验，分析了HEB在实际公交客车行驶工况下，电池组的散热性能；并通过对HEB电池箱的充放电试验，验证了CFD仿真计算的结果。最后，在热特性分析的基础上，提出了在电池箱中增设泄风口和可交替改变冷却空气流动方向的散热方法，并通过CFD仿真实验对其散热效果进行验证。
[Abstract]:Because of its good charge-discharge performance and safety performance, lithium-ion power battery has been widely used in Hybrid Electric bus HEB. In order to solve the problems of large difference of working temperature, large heat production and heat dissipation of LiFePO _ 4 / C _ (C) battery in Guangzhou, a LiFePO _ 4 / C _ 3 battery tank of HEB was used as the research object, in order to solve the problem of the difference in operating temperature, heat production and heat dissipation of the LiFePO _ 4 / C _ (C) battery in Guangzhou. In order to improve the heat dissipation performance of the LiFePO4/C power battery pack in the battery tank, the heat production and heat transfer characteristics of the LiFePO4/C power cell, the battery box and the battery tank are studied by using the method of experimental and computational fluid dynamics (CFD). The design method of heat dissipation structure of battery box based on heat dissipation performance is proposed. First of all, the relationship between temperature and battery capacity, internal resistance, open circuit voltage and charged state is studied through battery charge and discharge experiments and theoretical analysis and calculation of the thermal effect of LiFePO4/C cells. The mechanism of heat production and heat transfer during charge and discharge of LiFePO4/C power cell and the effects of convection heat transfer coefficient and air temperature on the heat dissipation performance of the cell are discussed. Then, based on the theory of fluid dynamics and heat transfer, the flow and heat transfer principle of air in HEB's LiFePO4/C battery tank is studied, and the geometry model and grid model of LiFePO4/C battery tank and battery pack are established. The mathematical model of air flow and heat transfer and the boundary conditions of CFD simulation are obtained by combining the test experiment of the battery cabin and the analysis of the thermal characteristics of the battery. On this basis, the air flow field and the temperature field of the LiFePO4/C battery pack are simulated by CFD, and the relationship between the cooling air flow and temperature distribution and the heat dissipation of the battery pack is analyzed. The heat transfer mechanism of the air channel in the battery box is discussed. Secondly, the HEB real vehicle test experiment is carried out, and the heat dissipation performance of HEB battery pack under the actual bus driving condition is analyzed, and the results of CFD simulation calculation are verified by charging and discharging test of HEB battery box. Finally, based on the analysis of thermal characteristics, a new method of heat dissipation is proposed, which can alternately change the flow direction of cooling air by adding a vent to the battery box, and the heat dissipation effect is verified by CFD simulation experiment.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U469.7;TM912

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