GB822824A - A steam generating system comprising a supercharged boiler - Google Patents

Abstract

822,824. Steam superheaters. ELLIOTT CO. Aug. 8, 1956, No. 24279/56. Class 123(3) [Also in Group XII] A steam power plant comprises a pressure-fired boiler 1 having an evaporator 2 from which steam-water mixture flows to a separator drum 9, steam flowing from the drum through a superheater 3 to a turbine 14. The boiler is fired by a burner 7 fed with oil or gas through a pipe 17 provided with a valve 18 and supplied with combustion air at a rate sufficient to maintain a pressure of from four to eight atmospheres in the furnace from a compressor 21 driven by a gas turbine 22. The gas turbine receives the exhaust gases from the boiler at a temperature which, under steady load conditions, is just high enough to allow the turbine to drive the compressor at the speed required for the delivery of the amount of air required at the particular load. A superheater by-pass 25 controlled by a damper 26 is provided in the boiler. Under steady load conditions the damper 26 is closed. When it is desired to increase the load rapidly, the fuel valve 18 is opened further whereupon the increased flow is sensed by a meter 29, the signal passing via a controller 28 to an operator 27 which opens the damper 26 sufficiently to cause such an increase in the gas turbine speed by virtue of the increase in exhaust gas temperature due to a proportion of the gas by-passing the superheater, that the compressor delivers to the burners the amount of air corresponding to the increased fuel rate. The opening of the damper 26 during periods of increasing load also protects the superheater from overheating by the suddenly increased flow of hot gases.