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AssigneeWestinghouse Electric Corp.
InventorsLyle F. Martz, Jack R. Smith, Francis A. Lebonette, Robert A. Putnam, Paul A. Berman
Estimating the term…
A combined cycle electric power generating plant includes gas and steam turbines and a heat recovery steam generator recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. The gas turbine includes a plurality of variably set guide vanes whose position may be set to determine the inlet flow to the gas turbine. Guide vane control apparatus is provided to limit the inlet guide vane position as a function of gas turbine compressor inlet temperature in accordance with a desired gas turbine exhaust flow, and to match the gas turbine exhaust flow to the steam requirements of the steam generator as in turn determined by the load placed upon its steam turbine. In addition, an afterburner is provided to supplementally heat the exhaust gas turbine gases before they are directed to the steam generator. During the startup, the afterburners are operated to supply supplemental heating to the gas turbine exhaust gases supplied to the steam generator whereby the temperature of the steam passed to the steam turbine is maintained at a minimum level. Further, the afterburners are fired to permit additional loading to be placed upon the steam turbine.
A load control system for a combined cycle electric power plant including a gas turbine having an exit through which heated exhaust gases pass, a variable inlet guide vane assembly for controlling the flow of air to said gas turbine and actuating means therefor, means for generating steam coupled to said gas turbine exit for transferring heat from the exhaust gases to a fluid passing through said steam generating means, a steam turbine coupled to said steam generating means and driven by the steam by the steam supplied thereby, means for generating electric power by the driving power of each of said turbines, an afterburner for supplying additional heat to the exhaust gases passing from said gas turbine to said steam generating means, and valve means for controlling the fuel flow to said afterburner, said load control system comprising means for controlling the fuel flow to said gas turbine in response to inputs including a plant load demand to provide for plant load changes between gas turbine minimum load and gas turbine base load at a relatively fast rate limited by gas turbine limitations until minimum afterburner firing occurs and at a slower rate limited by steam turbine limitations after minimum afterburner firing, means for controlling the position of said afterburner fuel valve means to provide steam under predetermined temperature conditions as the gas turbine loading is increased at the gas turbine limited rate between the gas turbine minumum load and a first higher gas turbine load at and above which minimum afterburner firing occurs, means for controlling the position of the gas turbine inlet guide vanes, and means for controlling the flow of steam to said steam turbine in a follow mode.
Dependencies are inferred from the claim text.