Automatic restart control for a power plant boiler
AssigneeWestinghouse Electric Corp.
InventorsMorton H. Binstock, Robert C. Lehmer, Steven J. Johnson, John J. Topolosky, Thomas E. Smith
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AssigneeWestinghouse Electric Corp.
InventorsMorton H. Binstock, Robert C. Lehmer, Steven J. Johnson, John J. Topolosky, Thomas E. Smith
Estimating the term…
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.
A hot restart control for a power plant having a boiler and a steam turbine with steam admission valve means for turbine steam flow and bypass valve means for bypass steam from the boiler to the plant condenser, said control comprising means for generating a turbine metal temperature signal, means for generating a boiler steam temperature signal, means for generating a boiler throttle pressure signal, computer means for generating a target boiler load and pressure for a turbine and steam temperature match in response to the turbine metal temperature and throttle pressure, means for controlling the boiler combustion to increase the boiler firing rate after a boiler shutdown with the turbine admission valve means closed so as to increase the boiler steam pressure and temperature with continuously adequate boiler steam flow, means for operating said bypass valve means to control the steam throttle pressure to a pressure setpoint based on the target pressure with the turbine admission valves remaining closed, means for detecting when boiler steam and turbine temperature match conditions exist and for holding said combustion controlling means when such match conditions are achieved, and means for controlling the opening movement of the turbine admission valves to transfer steam flow to the turbine from said bypass valve means so as to accelerate, synchronize and load the turbine as said bypass valve operating means provides steam throttle pressure control with closing bypass valve movement.
Dependencies are inferred from the claim text.