Combined cycle power plant and method for operation same

• Main Authors: LI HONGTAO, MAHIEUX CELINE, NAGEL HOLGER, NUGROHO TJIPTADY
• Format: Patent
• Language: English
• Published: 25.02.2015
• Subjects: BLASTING; ENGINE PLANTS IN GENERAL; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; STEAM ACCUMULATORS; STEAM ENGINE PLANTS; STEAM ENGINES; WEAPONS

Since CO2 is identified as a main greenhouse gas, its capture and storage is essential to control global warming. Flexible operation of CCPPs (combined cycle power plants) with CO2 capture system (18) will increase the competitiveness of CCPPs designed for CO2 capture and will allow earlier introduction of this kind of plants. The main objective of the present invention is to increase the CCPP net power and improve the operating characteristics by taking advantage of the additional power and flexibility, which can be obtained with supplementary firing (10) in CCPPs with flue gas recirculation and CO2 capture systems (18). One particular aim is to minimize the impact of CO2 capture on the capacity of a power plant, i.e. to maximize the electric power the plant can deliver to the power grid. To this end an operating method, in which the power consumption of CO2 capture system is at least partly compensated by the operation of supplementary firing (10) in a HRSG (9) with low residual oxygen concentration in the flue gases (8), which is due to flue gas recirculation, is proposed. Further, additional ambient air and/or oxygen (11) injection into the supplementary firing (10) with corresponding operating methods are proposed. Besides the method a CCPP designed to operate according to this method is subject of the present invention.