Automatic restart control for a power plant boiler

摘要

An automatic control is provided for fast restarts of a hot power plant. Boiler fuel demand is increased to reach a target load based on measured turbine metal temperature and throttle pressure. Fine tuning of the fuel demand is performed to achieve an actual match between the turbine and steam temperatures. Turbine bypass valves are operated during boiler firing the control steam pressure to a programmed pressure setpoint. Boiler firing rate is high limited by total boiler outlet steam to avoid flow overheating and bypass valve position is low limited in accordance with steam flow and throttle pressure to avoid excessively low steam flow. Reheater controls are operated to match intermediate turbine temperature and reheat steam temperature.