INTEGRATED GASIFICATION COMBINED CYCLE AND METHOD FOR OPERATING INTEGRATED GASIFICATION COMBINED CYCLE

摘要

Provided is an integrated coal gasification combined cycle equipped with: a gasifier that generates combustible gas from pulverized coal; a gas cooler; gas turbine equipment; an auxiliary fuel supply unit that supplies an auxiliary fuel to the gas turbine equipment; a heat recovery steam generator; steam turbine equipment; generators; and a circulation line unit that circulates cooling water. The heat recovery steam generator has a first medium-pressure coal economizer and a second medium-pressure coal economizer. When the combustible gas generated from the pulverized coal is burned, a serial heat exchange line is formed wherein cooling water passes through the first medium-pressure coal economizer, the second medium-pressure coal economizer, and the gas cooler. When the auxiliary fuel is burned, separate heat exchange lines are formed, wherein the cooling water separately passes through the first medium-pressure coal economizer and the second medium-pressure coal economizer.