摘要
岭澳核电站应急柴油机进气阀导管裂纹、断裂缺陷将导致柴油机拉缸,直至柴油发电机组不可用。根据气阀导管结构、材料、运行受力、翻新检修过程分析,结合外部反馈信息,发现缸头进气阀导管较排气阀导管长约12 mm,且支撑距离短;材料为高磷铸铁,易产生裂纹。指出柴油机缸头翻新过程中,气阀修磨工具定位杆锥面与导管口接触,可能造成初始裂纹。根据分析,提出采用行车配合缓降器和无损检测相结合的处理措施。
Fracture or crack of emergency diesel engine intake valve guides will cause the pistons scraping, until the emergency diesel-generator set unavailable in Ling Ao nuclear power plant. According to the analysis of intake valve guide structure, material, operating stress, requalification process and external experience feedback, it was found that the intake valve guides are 12 mm longer than exhaust valve guides and supports are shorter, the material is high phosphorus cast iron and easy to crack. It was pointed out that the locating rod cone of the valve seat grinding machine was contact with the end of the intake valve guide during the requalification, and that is the possible root-cause of the initial cracks. The treatment is to adopt the descent control device to lift the grinding machine, and valve guides NDT inspection after valve seats grinding.
出处
《机械》
2008年第11期76-80,共5页
Machinery
关键词
柴油机
进气阀导管
断裂
裂纹
diesel engine
intake valve guide
fracture
crack
