Combined cycle power plant and method for operating such a combined cycle power plant

• Main Authors: LI HONGTAO, PEDRETTI CAMILLE, RUCHTI CHRISTOPH, NUGROHO TJIPTADY
• Format: Patent
• Language: English
• Published: 14.10.2015
• Subjects: AIR INTAKES FOR JET-PROPULSION PLANTS; BLASTING; COMBUSTION ENGINES; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS; ENGINE PLANTS IN GENERAL; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES; GAS-TURBINE PLANTS; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; STEAM ACCUMULATORS; STEAM ENGINE PLANTS; STEAM ENGINES; WEAPONS

The invention relates to a combined cycle power plant (10a) comprising a gas turbine (11a,b) the exhaust gas outlet of which is connected to a heat recovery steam generator (19), which is part of a water/steam cycle (35), whereby, for having a large power reserve and at the same time a higher design performance when operated at base load, the gas turbine (11a) is designed with a steam injection capability (26) for power augmentation. For having a large power reserve at improved and optimized design performance when the plant is being operated at base load, the gas turbine (11a) comprises at least one combustor (15, 16), and a compressor (12) for providing cooling air for that gas turbine (11a,b), which is extracted from the compressor (12) and cooled down in at least one cooling air cooler (17, 18). The steam for steam injection is generated in said cooling air cooler (17, 18), whereby said steam is injected into an air side inlet or outlet of said cooling air cooler (17, 18) and/or directly into said at least one combustor (15, 16). The heat recovery steam generator (19) is equipped with a supplementary firing (22, 22'), which is at least a single stage supplementary firing (22) to increase the high pressure steam production and providing augmentation power as power reserve to a grid when required.