Thermodynamic analysis of a partial gasification pressurized combustion and supercritical steam combined cycle

The aim of this paper is to study the thermodynamic performance of a new combination of a partial gasification pressurized combustion gas cycle and a supercritical steam cycle as a means of advanced 'clean coal' power generation. Energy and exergy analyses of the proposed power cycle are presented. The effects of pressure ratio of the gas cycle, the turbine inlet temperature (TIT) and amount of coal gasification on the thermodynamic performance of the combined cycle are discussed. The optimum pressure ratio has to be determined on the basis of a judicious compromise between the net power and the overall efficiency. Overall efficiency is the maximum for an optimum TIT. The relative coal feeds for partial gasification and pressurized combustion may be adjusted with a compromise between net power and overall efficiency. The power output of the cycle can be increased by more coal gasification. However, this yields a lower overall efficiency.