蒸汽轮机高转速条件下饱和蒸汽在线清垢

On-line fouling cleaning by saturated steam for steam turbine running at a high speed

蒸汽轮机是催化裂化装置机组中最易结垢的关键设备,介绍某催化裂化装置蒸汽轮机结垢后产生的转速下降、压缩机负荷降低、汽轮机蒸汽耗量上升、入口蒸汽阀门全开、汽轮机轴位移由正向变为负向、汽轮机室压力上升等现象,并在研究其他企业汽轮机在线清洗的相关文献和饱和蒸汽压力温度曲线后,决定在高转速条件下用湿饱和蒸汽对蒸汽轮机进行在线清洗。清洗结束后,汽轮机轴位移由-80 mm(负向)变为200 mm(正向),转速由4 900 r/min恢复到接近5 300 r/min,入口蒸汽调节阀门开度由100%下降到60%,汽轮机室压力由3. 1 MPa下降到1. 8 MPa,3. 5 MPa中压蒸汽耗量由52 t/h下降到45 t/h,取得了显著的效果,保证了装置的经济效益。通过对蒸汽轮机出口低压蒸汽排凝液化验数据分析得知结垢的主要成分为钠盐。

Steam turbine is the key equipment which is most prone to fouling in the fluid catalytic cracking unit. Here introduced are the phenomenons of steam turbine speed slowing,compressor load reducing,steam consumption increasing,inlet steam valve fully opening,axial translation of steam turbine changing from positive to negative,the pressure in steam turbine chamber increasing,etc after fouling of steam turbine. After study of related literature of other companies about steam turbine online cleaning and pressure & temperature curves of saturated steam,it was decided to conduct on-line cleaning for steam turbine with wet saturated steam at high-speed condition. After cleaning,axial translation of steam turbine was changed from-80 mm to200 mm,steam turbine speed was restored from 4 900 r/min to 5 300 r/min,opening of inlet steam valve went down from 100% to 60%,the pressure in steam turbine chamber dropped from 3. 1 MPa to 1. 8 MPa,3. 5 MPa medium pressure steam consumption dropped from 52 t/h to 45 t/h. Good results have been achieved and satisfactory economic benefits have been obtained. The analysis of the condensate of low-pressure steam from the outlet of steam turbine showed that the dirt of steam turbine was mainly sodium salt.