Abstract: In a combined cycle electrical power generator plant, the shut-down process includes a cooldown control period which is minimized before shutting down the gas turbine by detecting first whether a non-steaming condition has been reached and whether the gas turbine has been reduced to minimum load.

Abstract: A coupling controller opens a dump valve at the outlet of a heat recovery steam generator when such generator is to be coupled to another generator being in operation with a steam turbine on a common header. The controller gradually permits pressure build-up until the pressure at the outlet of the new generator matches the pressure behind the header. The controller also responds to critical conditions in the superheater as well as in the high pressure drum of the generator in the operation.

Abstract: Boiler feedpump net positive suction head (NPSH) control is performed in a heat recovery steam generator including a deaerator inserted between steam turbine condensate and steam boiler. To this effect apparatus is provided responsive to temperature at the output of the deaerator, to fluid flow therefrom, and to temperature at the input of the boiler feedpump for providing a signal representative of the anticipated suction head pressure, and the NPSH margin is derived by comparison with actual pressure to control the pegging valve, or other heat source control to the deaerator.