华电技术 ›› 2017, Vol. 39 ›› Issue (5): 32-35.

• 技术交流 • 上一篇    下一篇

670MW超临界机组切阀失败原因分析与处理

  

  1. 辽宁东科电力有限公司,沈阳〓110006
  • 出版日期:2017-05-25

670MW supercritical unit valve switching failure cause analysis and treatment

  1. Liaoning Dongke Electrical Power Company Limited, Shenyang 110006, China
  • Published:2017-05-25

摘要:

某电厂670MW超临界机组启动阶段,汽轮机转速达2900r/min时高压主汽阀(TV)-高压调节汽阀(GV)切阀过程中TV无法全开,导致切阀失败。通过分析高中压缸联合启动转速和切阀控制逻辑,剖析主汽阀内部结构及动作原理,对比切阀前后参数并分析主汽阀开启时的受力,得出主蒸汽压力和再热蒸汽压力过低导致切阀失败的结论。提出在切阀前调整主蒸汽压力和再热蒸汽压力,尽可能减小GV开度,以降低阀前后差压,确保了切阀成功并缩短了切阀时间。

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Abstract:

In a power plant’s 670MW supercritical unit startup stage, valve switching of total valve (TV) and governing valve (GV) failed. After analyzing HPIP cylinder unite startup speed and valve switching logic, and comparing the stress of main stop valve before and after opening, the failure cause was indicated that main steam pressure and reheat steam pressure are too low. Authors claimed that by adjusting the pressure of main steam and reheat steam would reduce the opening and pressure difference of GV. This will ensure the success of valve switching and reduce the valve switching time.

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