350 MW机组汽封间隙调整及通流改造方案

Seal Clearance Adjustment and Flow Path Improvement in 350 MW Unit

在华能大连电厂3号机组A级检修过程中,发现高压外缸上抬量很大,且在未紧螺栓的情况下高压外缸间隙严重超标。通过计算半缸与全实缸洼窝中心的差值、测量各级隔板的椭圆度、改变螺栓热紧角度等措施,调整了轴系中心和汽封间隙。从启机过程和最后效率实验结果来看,这种方法是可行的。研究成果可为类似机组检修提供借鉴。

During the overhaul of No.3 turbine unit in Huaneng Dalian Power Plant,it was observed that the high pressure outer cylinder was excessively lifted and the clearance of the high pressure outer cylinder seriously exceeded standard while the bolts were not tightened.The differential value between the cavity center of semi cylinder and whole cylinder was calculated,the ellipticity of every stage of diaphragm was measured,and the bolt hot tightening angle was changed,so that the shafting center and seal clearance were adjusted.This method was proved to be feasible by the start-up process and the final efficiency experiment.The research result can provide reference for maintenance in similar turbine units.