METHOD AND DEVICE FOR OPERATING COMBINED-CYCLE PLANT (OPTIONS) Russian patent published in 1998 - IPC

FIELD: power plants burning solid fuels such as lignites. SUBSTANCE: hot compressed air is heated in heat exchanger boiler charged with stack gases, indirectly heated to high temperature by means of separate auxiliary furnace, and supplied to gas turbine. Combined-cycle plant may be optionally provided with supercharged boiler wherein solid fuel such as lignite is burned to form boiler stack gases which are heated to high temperature in separate auxiliary furnace and fed to gas turbine. Auxiliary furnace solid fuel and has slagging bottom. Auxiliary-furnace stack gases are used separately or together with exit air of gas turbine for power generation in combined cycle or in separate process. Device implementing this method has auxiliary furnace 18 placed between boiler 1 provided with heat exchangers 7, 8 and gas turbine 28; it has section of air heater 19. Entrance end 26 of section of air heater 19 is connected to boiler 1 and exit end 27, to gas turbine 28. Stack gas outlet 25 and liquid ash outlet of auxiliary furnace burning solid fuel are connected separately or together with gas-turbine exit gas outlet 29 to boiler 1 and/or to fuel pulverizing unit 3, and/or to waste-heat unit. EFFECT: improved efficiency. 26 cl, 7 dwg