A high-parameter gas turbine and supercritical carbon dioxide(S-CO_2) combined cycle model was constructed

and thermal performance analysis was carried out. The top cycle uses a high-parameter gas turbine with a combustion chamber exhaust temperature of 1 800 ℃

and the bottom cycle adopts S-CO_2 Rankine double turbine cycle

while using three-stage flue gas heating and two-stage turbine exhaust gas recovery. The parameters and thermal performance under the optimized combined cycle operating conditions are obtained by the penalty function method. The influences of the main parameters of the high-parameter gas turbine top cycle and S-CO_2 Rankine bottom cycle on the combined cycle performance is analyzed. The results show that the combined cycle thermal efficiency can reach 68.61% at the gas turbine pressure ratio of 35.5 and the combustion chamber outlet temperature of 1 800 ℃

and the efficiency of the combined cycle of the gas turbine and S-CO_2 is 2.3 percentage points higher than that of the combined cycle of the gas turbine and steam.