超超临界1000 MW空冷机组汽轮机安装要点与消振措施

Installation characteristics and anti vibration measures of a 1 000MW ultra-supercritical air-cooled steam turbine

介绍了超超临界1 000 MW空冷机组汽轮机的安装要点,对其在调试过程中发生的汽流激振进行了分析,并提出了以下处理方案:(1)通过改变轴承标高增大轴承预载荷,进而提高轴承的动态比压;(2)增加系统阻尼,提高了系统稳定裕度;(3)调整隔板汽封间隙,使上半缸小于下半缸0.06～0.10mm,喷嘴至调节级动叶的轴向距离减少0.20～0.25 mm;调节阀顺序由原来的1,2、3,4改为2,1、4,3.按照该方案处理后,机组启动过程顺利,运行稳定.

Main problems that should be paid attention during installation of the ultra-supercritical1000MW air-cooled unit steam turbine were presented.Moreover,the steam flow excited vibration(SFEV)occurred during the debugging process was analyzed and several countermeasures were proposed.The bearing preload was increased to improve its dynamic specific pressure by changing its elevation.The system damping was increased to enhance the stability margin.Keep gap width of the diaphragm gland of the upper cylinder be about 0.06mm to 0.10mm smaller than that of the lower cylinder,the axial distance between the nozzle and the governing stage blade was shortened by about 0.20mm to 0.25mm.The original sequence of the control valve 1,2,3,4was changed into 2,1,4,3.After the improvement,the unit can start up successfully and run stably.