New Humidification Concept for Evaporative Gas Turbine Cycles Applied to a Modern Aeroderivative Gas Turbine

Abstract A new humidification concept in evaporative gas turbine cycles is presented. This involves a humidfication column with multiple sections of counter-current humidification with different water flows in each section. The advantages of multiple sections are analyzed in combination with part-flow humidification, where less than 50% of the compressed air from the air compressor is led through the humidification column and the rest is passed on directly to the recuperator. The part flow humidification is a concept that noticeably reduces mass and heat transfer equipment costs in the EvGT cycle. It is shown that, for a part flow configuration, a more efficient cycle can be attained than in a system with customary single-section humidification. In this paper an EvGT system is modeled in the GATE/CYCLE gas turbine simulation program. The simulations are based on the modem aeroderivative gas turbine Rolls Royce Trent in non-intercooled mode. The results include performance data as well as dimensions and design considerations of the humidification column and the heat exchangers.