Development of semiclosed cycle gas turbine for highly-efficient oxy-fuel IGCC power generation with CO2 capture -combustion promotion by split supply of recirculated exhaust for oxy-fueled combustors

Oxy-fuel IGCC (integrated coal gasification combined cycle) power generation employing the oxygen-fired, semiclosed cycle gas turbine with exhaust recirculation enables the realization of highly efficient, zero-emission power generation. In order to realize the oxy-fuel IGCC, we have to develop the combustion promotion technologies of the CO-rich gasified fuel/oxygen-fired stoichiometric combustion with recirculated exhaust. In this study, the effects of the recirculated exhaust split supply in gas turbine combustors on the emission characteristics have been examined through numerical analyses based on reaction kinetics with multistage reactor models of combustors. It was clarified that the fuel oxidation reaction rates increased and the chain initiation reaction in the primary combustion zone was hastened by the recirculated exhaust split supply, and then combustion efficiency improved.