液氧-甲烷发动机点火器接口过度烧蚀问题研究

Study on Excessive Ablation of the Ignitor Interface of Liquid Oxygen-Methane Engine

针对某液氧-甲烷发动机试车中出现的点火器与管路接口过度烧蚀问题,进行了原因分析及试验验证,提出改进措施并对其进行试验验证。结果表明:接口倒台阶和缝隙过大是造成过度烧蚀的原因。采用“突变式”变径结构代替“斜面过度”变径结构,可避免点火器与管路内径公差设计不合理及装配不对位造成的倒台阶问题;并且,将石墨垫圈厚度由4.0~4.5 mm调整为2.6~3.0 mm,可使压紧后接口缝隙小于0.1 mm。试验表明改进措施有效。

Aimed at the issue of excessive ablation of the interface between the ignitor and the pipeline during the test run of some liquidoxygen-methane engine,cause analysis and experimental verification were conducted,and the improvement measures were proposed and verified by test.The results show that the excessive ablation is caused by the inverted step and oversizedgap at the interface.By using a"sudden change"variable diameter structure instead of a"excessive slope"variable diameter structure,the problem of the inverted step caused by unreasonable tolerance design of the ignitor and pipeline inner diameter and misaligned assembly can be avoided;And adjusting the thickness of the graphite washer from 4.0~4.5 mm to 2.6~3.0 mm can make the interface gapafter compression less than 0.1 mm.The test indicates that the improvement measures are effective.