High-Temperature-Turbine Technology Program: Phase II. Technology Test and Support Studies. Update of Overall Plant-Design Description-Combined-Cycle Electric-Power Plant with Integrated Low-Btu-Gas Plant

摘要

Changes made to the preliminary design of a commercial combined cycle electric powerplant operating on low Btu gas fuel are described. Major elements changed were: gas turbine configuration; gas desulfurization system; gas cleanup system; and the steam system operating parameters. The net power output of this base load station was increased from 750 MW to 1032 MW, by increasing the size of the four gas turbines. The gas turbine configuration was changed from a 2-spool, annular burner arrangement to a single shaft engine with can-type combustors. Firing temperature is revised from 3000 to 2750 exp 0 F. The free power turbine arrangement of the original powerplant concept which permits double-ending the electrical generators was retained. The steam system configuration is changed from an 1800/1000 single level system to a 2400/1000/1000 single reheat configuration which utilizes heat extraction from the hot flue gas down to 280 exp 0 F, delivers gasifier steam and jacket water and provides fuel gas preheat. The steam system produces 376.MW of electrical power. The high temperature gas desulfurization and cleanup system of the original powerplant design is replaced by a cold water wash and a commercial Selexol desulfurization unit. This change produced a substantial reduction in overall powerplant efficiency, but was necessary because the previously-used developmental hot gas cleanup system has not advanced to commercial status. The Lurgi fixed bed gasifier utilized in the original powerplant concept was retained. The modular arrangement of the original powerplant design was retained. The overall powerplant coal pile to bus bar efficiency is 40.5%, conservatively based on demonstrated performance of individual commercial or near-commercial components utilized in the design. (ERA citation 07:046575)