Combined gas- and steam-turbine power station having coal gasification

摘要

In a combined gas- and steam-turbine power station having an integrated coal gasification system, the problem arises of incorporating the sensible waste heat from the coal gasification, which results during the cooling of the raw gas, into the power-station process in such a manner that as high as possible an efficiency for the entire process results. The novel method functions with a combined gas- and steam-turbine process, the fuel gas for the gas turbine being generated in a coal-gasification system (50-56). The carbon-containing gasification residue (63) is burned in an atmospheric fluidised-bed combustion system (8) which is arranged in the exhaust gas flow of the gas turbine (2). Optimal utilisation of the waste heat from the coal gasification is achieved in that the said heat (52) is incorporated, with the aid of a heat-transfer circuit (20) having a liquid heat carrier, such as sodium, into the steam process and is used there for superheating (23) or reheating (24) of steam. Furthermore, the heat-transfer circuit is used to preheat (22) compressed air from the gas turbine to approximately 600@C. The method is used for generating electrical energy from solid fuel with a high degree of conversion. <IMAGE>