汽轮机中分面漏汽的现场处理技术与应用

On-site Treatment of Steam Leakage at Turbine Casing Split

分析了可能导致大功率汽轮机汽缸中分面漏汽的原因,基于镍基金属密封条高温下发生膨胀的特性及密封原理,将镍基金属密封条配合相应尺寸的密封槽共同应用于汽缸中分面漏汽位置,以此实现对蒸汽的密封。设计了一种大型汽缸中分面开槽专用设备,通过对加工工艺的摸索以及工程实践检验,得到了整套开槽工艺。结果表明:通过合理计算并预留密封条的预压量,可保证密封条在高温下发生膨胀,贴紧密封面,进而起到密封的效果,达到有效阻止蒸汽泄漏的目的;现场铣削加工密封槽工艺可靠。

Considering the high-temperature expansion property of Ni-based metallic seal and its sealing principle, causes that may lead to steam leakage at casing split of large capacity steam turbines were analyzed, based on which an on-site treatment measure was proposed by simultaneously adopting both the Ni-based metallic seal and the seal groove at the leaking position. Specific groove cutting machine was designed and a complete set of groove cutting procedure was worked out through trial practice. Results show that the steam leakage can be prevented by reasonably setting the seal preload so as to guarantee enough expansion of the sealing strip and to make it contact with the sealing surface tightly.