抄録
The reduction of the CO_2 exhaust is now important problem all over the world. Improving the thermal efficiency of the internal combustion engine becomes one of the solutions for that. Separating CO_2 and N_2 in the low-calorie fuel will improve the thermal efficiency of the engine. In this study the numerical simulation model of the gas turbine combined cycle is constructed with the Brayton cycle, the Rankine cycle and the heat exchange steam boiler and the thermal efficiency was quantitatively evaluated in the various fuel cases. Both thermal efficiencies have improved 2.0% and 3.4% by separating N_2 and CO_2. It is concluded that separating CO_2 whose specific heat ratio is smaller than N_2, improves the thermal efficiency better because it makes combustion temperature higher and compression load lower.
