CRH2型动车组用干燥装置后冷却器密封垫优化改进

Optimization of the Rear Cooler Sealing Gasket of the Drying Unit for CRH2 EMU

目前CRH2型动车组用干燥装置后冷却器使用华尔卡6501无石棉密封垫进行密封,该密封垫为高级修必换件,早期CRH2型动车组高级修里程为90万km,2011年检修修程延长至120万km,随着检修修程延长,因密封垫性能下降,在接近高级修里程时(100万至120万km)批量出现泄漏故障。通过故障分析,该密封垫随着使用时间增加,在接近高级修时,耐温性能、安装面压等方面出现无法满足使用要求现象,结合轨道交通及其他行业经验,优化密封垫材质及结构,将无石棉垫更改为金属覆胶密封垫,提高了密封面压及耐温性,避免长期使用后因密封垫老化导致的泄漏问题。优化后的密封垫通过地面试验验证及小批量装车验证,效果良好,可以彻底解决CRH2型平台动车组用干燥装置后冷却器密封垫泄漏问题。

At present,the rear cooler of the drying unit for the CRH2 EMU is sealed with a Valqua 6501 non-asbestos sealing gasket.This sealing gasket is a part that must be replaced during advanced maintenance.In the early phase,the advanced maintenance cycle of the CRH2 EMU was 900000 km,but in 2011,this maintenance cycle was extended to 1200000 km.With the extension of the maintenance cycle,as the performance of sealing gaskets degrades,leakage failures occur in large quantity when approaching the end of the advanced maintenance cycle(1000000~ 1200000 km).It turns out from fault analysis that as the time of utilization goes on,when approaching the end of the advanced maintenance cycle,this sealing gasket can't meet the requirements of service in terms of temperature resistance and pressure on the installation surface.This article combines the experiences of rail transit and other industries and optimizes the material and structure of the sealing gasket.It replaces the non-asbestos gasket with a metallic gasket coated with rubber so as to improve the pressure on the installation surface and the temperature resistance and avoid the leakage caused by the aging of the sealing gasket after long use.The optimized sealing gasket has been verified by the ground test and the test on the car in small quantity with a good effect,so it can thoroughly solve the leakage problem of the rear cooler sealing gasket of the drying unit for CRH2 EMU.