Improved Reheat Steam Temperature Control Strategy For A 600MW Coal-fired Power Plant

At present,the reheater is an essential part of the boiler in the large coal-fired power plant,so it is very important to improve the control quality of the reheat steam temperature control system.The purpose of the reheat steam temperature control is to follow up the setpoint value,protect the reheater from over temperature and keep the steam temperature stable,so as to ensure the operation of the power plant safely and economically.This article is based on the 600 MW coal-fired power plant at Shanghai Wujing No.2 Power Generation Co.Ltd..The current reheat steam temperature control system is characterized with burner tilting angle of burner as main control and desuperheating water as auxiliary control,however,it encounters daily problems such as time delay and overshooting.In this article,theoretical analysis is performed at first.Based on the daily operation data mining,the burner tilting and water desuperheating is optimized,and a state-variable control strategy is proposed.The logic of the reheat steam control system is also optimized.The control strategy is tested and the parameters are adjusted in real operation.Compared to the current reheat steam control method,the improved control strategy has achieved better control performance,which increases the speed of load responses under AGC and ensures the safe operation of the two units.