300MW汽轮机高压缸上下缸温差大原因分析

Cause Analysis and Discussion on Large Temperature Difference Between Upper and Lower Cylinders of High Pressure Cylinder of 300MW Steam Turbine

以某电厂出现的汽轮机高压缸上下缸温差大问题作为切入点,从设计和操作等方面,分析问题的原因为高压旁路阀、高压旁路减温水、高压旁路逆止阀门存在泄漏,导致停机过程中高压缸内温差出现异常,提出设计安装阶段,合理布置机组疏水系统,机组启动中,上下缸出现温度差时,要时刻关注温差值、变化率,及时查找原因,根据不同蒸汽参数选择相应启机方式,严格遵守机组运行规程。

Taking the problem of large temperature difference between the upper and lower cylinders of steam turbine high-pressure cylinder in a power plant as the starting point,it is analyzed from the aspects of design and operation that the cause of the problem is the leakage of the high-pressure bypass valve,the desuperheating water of the high-pressure bypass and the check valve of the high-pressure bypass,resulting in abnormal temperature difference in the high-pressure cylinder during shutdown.It is proposed to reasonably arrange the unit drainage system in the design and installation stage.During unit startup,in case of temperature difference between upper and lower cylinders,always pay attention to the temperature difference value and change rate,find out the cause in time,select the corresponding startup mode according to different steam parameters,and strictly abide by the unit operation rules.