补汽阀投用对1000MW机组夏季运行工况的影响

Influence of overload valve on 1 000 MW unit operation condition in summer

阐述了采用西门子补汽阀技术的1 000 MW机组夏季工况下补汽阀投用与否对机组的功率响应、中间点汽温、主汽压力等参数的影响,对投用补汽阀后机组的经济性作了评估说明。夏季工况下不投用补汽阀,1 000 MW机组在额定参数下无法达到额定功率,并且在AGC(自动发电控制)方式下机组主要参数波动较大,不利于机组稳定运行。投用补汽阀运行,则增大汽轮机的节流损失,降低机组运行效率。如果提高蒸汽参数运行,锅炉金属受热面所能承受的温度上限将下降,金属管壁将更容易超温。因此建议在夏季工况下,对该类型的1 000 MW机组负荷调度采用AGC模式下的人工输入方式,由调度员在线设定机组的目标功率。

The influence of overload valve provided by Siemens, on the power response, middle point temperature, main steam pressure and economic performance in 1 000 MW unit in summer condition was discussed. Rated power can not be achieved for such 1 000 MW units with rated parameters in summer condition without overload valve. The main parameters change greatly in AGC Auto marie Generation Control mode, which militates against stable operation. Once overload valve was put into use, the throttle lose of main steam must be increased and the efficiency of unit was decreased. If the main steam pressure was raised, the temperature that boiler metal can withstand will be dropped, and overheating of the tube wall must be very common. So load dispatch should be run in manual manner of AGC mode in summer condition, and the object power should be set by dispatcher on line.