Abstract:

The poor working conditions of EGR cooler often is due to excessive thermal load and the emergence of structure crack problem, which influences seriously its actual performance. The fluid field, the temperature and thermal stress distribution of cooler were calculated by using computational fluid dynamics and finite element analysis software with fluid-solid coupling thermal analysis technique. The results of calculation well agree with test data and it is concluded that the cracks on EGR cooler are caused by high thermal stress. Accordingly the cooler structure was improved, the outer surface increased turbulence slots. The cooler with that configuration has obviously lower thermal stress and cracks no longer happen again, indicating fluid-solid coupling thermal analysis being an effective way for solving the crack problem of EGR cooler.

Key words: exhaust gas recirculation(EGR) cooler, thermal stress, fluid-solid coupling, turbulence slots

摘要：

废气再循环(EGR)冷却器的工作条件恶劣，经常由于热负荷过高而出现结构开裂问题，严重影响实际使用性能。针对某型EGR冷却器，采用流固耦合热分析方法，用计算流体力学和有限元软件计算分析了EGR冷却器的流场、温度场和热应力分布，其数值模拟结果与测试结果吻合;验证了EGR冷却器的开裂现象系工作时所受热应力过高导致。据此，通过在外表面增加扰流槽对EGR冷却器结构进行了一定的改进，试验结果表明，改进后的EGR冷却器不再出现开裂现象，研究结果表明流固耦合分析是解决EGR冷却器开裂问题的有效方法。

关键词: 废气再循环冷却器, 热应力, 流固耦合, 扰流槽