Turbine cooling system is one of the cores of modern heavy-duty gas turbines. How to consider the influence of cold gas admixture is one of the first problems to be solved in gas turbine thermodynamic modeling and analysis of the influence of key parameters. With the continuous deepening of overall design of the gas turbine

a more detailed thermal performance calculation model is required to coordinate and match key components and the whole and ensure the final realization of the design performance. A calculation method of step-by-step blending and overall thermal performance of gas turbine based on one-dimensional aerodynamic analysis of turbine is proposed

and a thermal performance model of heavy-duty gas turbine is established. Moreover

the influence and key parameters and thermodynamic performance scheme of G/H class gas turbine is investigated. The analysis shows that

the turbine initial temperature

pressure ratio and cooling air volume are the key parameters affecting the overall thermal performance of the gas turbine

and the three should be coordinated in the overall design. While improving the turbine initial temperature

the minimum cooling air amount required to reach the temperature level should be studied

the optimal pressure ratio should be analyzed

and the iterative calculation and thorough research should be confirmed after combining the component design. The research results can provide a reference for the overall performance design of autonomous heavy-duty gas turbines.