换热器结构对氢燃料电池冷起动性能影响的仿真分析

刘洋洋¹，崔万鑫²，鲍尊俊¹，张黍涵¹，孔祥安¹，吕承举³，陈忠言⁴，李新海^1*

1.山东建筑大学机电工程学院，山东 济南  250101；2.中国重型汽车集团有限公司，山东 济南  250101；

3.山东省交通科学研究院，山东 济南  250031； 4.山东氢探新能源科技有限公司，山东 济南  250109

摘要：为解决质子交换膜燃料电池（proton exchange membrane fuel cell，PEMFC）在超低温环境下起动困难的问题，提出解决氢燃料电池冷起动困难问题的方案，通过氢燃烧器产生高温燃气，经换热器加热冷却液，由冷却液小循环提高电堆温度，以缩短冷起动时间，提高燃料电池冷起动性能。采用计算流体动力学（computational fluid dynamics，CFD）方法，基于AVL_FIRE软件建立管壳式换热器三维仿真模型，对换热器换热性能进行数值分析与迭代优化；针对初始模型换热效率低、冷却液温度分布不均等问题，提出缩短换热器进出口长度并调整铜管分布、增设挡板改变气流路径、增大流体进口管径、减小换热器长度削除尾部低效换热区域等4种优化方案。仿真结果显示：第4种优化方案使冷却液出口温度较进口温度提高36 K，满足冷起动系统对冷却液温升的要求，为最佳选择方案。

关键词：质子交换膜燃料电池；低温冷起动；换热器；数值仿真

Simulation analysis of hydrogen fuel cell heat exchanger structure on cold start performance

LIU Yangyang¹, CUI Wanxin², BAO Zunjun¹, ZHANG Shuhan¹, KONG Xiang′an¹, LÜ Chengju³, CHEN Zhongyan⁴, LI Xinhai^1*

1.School of Mechanical and Electronic Engineering, Shandong Jianzhu University, Jinan 250101, China；

2.China National Heavy Duty Truck Group, Co., Ltd., Jinan 250101, China；

3.Shandong Transportation Research Institute, Jinan 250031, China；

4. Shandong Fuel Cell Power in Technology Co., Ltd., Jinan 250109, China

Abstract: To solve the problem of difficult start of proton exchange membrane fuel cell (PEMFC) in ultra-low temperature environment, a solution to the difficult cold startup of hydrogen cells is proposed. By generating high-temperature gas with a hydrogen burner, the coolant is heated by a heat exchanger, and the stack temperature is improved by a small cycle coolant to reduce the cold startup time and improve the cold startup performance of fuel cells. The computational fluid dynamics（CFD）method is used to establish a three-dimensional model of the shell-and-tube heat exchanger based on AVL_FIRE software, and the heat exchange performance of the heat exchanger is numerically analyzed. In view of the low heat exchange efficiency and uneven temperature distribution of the initial model, four optimization schemes are proposed, including shortening the length of the heat exchanger inlet and and adjusting the distribution of copper tubes, setting baffles to change the airflow path，increasing the diameter of the fluid inlet pipe, and reducing the length of the heat exchanger to eliminate the low-efficiency heat exchange area at the tail. The simulation results show that the fourth optimization scheme increases the temperature of outlet cooling water by 36 K compared with the inlet temperature, which meets the requirements of the cold start system for the temperature rise of the cooling water and is the best option.

Keywords: proton exchange membrane fuel cell (PEMFC); low-temperature cold start; heat exchanger; numerical simulation