柴油机废气再循环冷却器翅片断裂分析及优化

Fracture Analysis and Optimization of Fin of ECR Cooler of Diesel Engine

针对某柴油机废气再循环冷却器进气口直齿翅片出现断裂问题,进行分析与优化。基于热流固耦合仿真方法,对废气再循环冷却器进行温度场与应变分析,结合翅片断裂处扫描电镜图像,确定断裂原因为热疲劳。为了解决热疲劳问题,设计三种方案,进行温度和应变仿真分析。三种方案分别为采用SUS444不锈钢材料,翅片厚度增大,将翅片向内缩进。将三种方案结合,采用综合方案完成优化,有效降低了翅片温度,减小了应变,并且通过冷热循环试验验证。

Aiming at the fracture problem of the spur fin of the air inlet of the exhaust gas recirculation cooler of a diesel engine,analysis and optimization were carried out.Based on the thermal fluid-structure interaction simulation method,the temperature field analysis and strain analysis of the exhaust gas recirculation cooler were carried out,and the scanning electron microscope image of the fin fracture was combined to determine that the cause of the fracture was thermal fatigue.In order to solve the problem of thermal fatigue,three schemes were designed to carry out temperature and strain simulation analysis.The three solutions are made of SUS444 stainless steel,and the thickness of the fin is increased and the fin is indented.The combination of the three schemes was carried out,and the comprehensive scheme was used to complete the optimization,which effectively reduced the fin temperature and strain,and was verified by the cold and hot cycle test.