Influence of the Cooling Technology on the Efficiency of Gas-Turbine Power Plants

Along with improving the cooling technology, increasing the combustor outlet temperature is currently one of the main ways to raise the efficiency of both gas-turbine and combined-cycle power plants. The efficiency of the cooling technology is determined by four main parameters: internal cooling efficiency, film cooling effectiveness, Biot numbers for the blade metal and thermal barrier coating. This paper presents comprehensive calculations of gas turbine performance with varying combustor outlet temperature, compressor pressure ratio, and cooling efficiency. With modern cooling systems, an increase in the inlet gas temperature by 100°C leads to an increase in the efficiency of the combined-cycle plant by 0.5 – 0.8%. An increase in the inlet gas temperature to 1600°C with simultaneous improvement of the cooling technology will increase the efficiency of combined-cycle power plants to 62 – 63% and higher. The calculations provide an overview and lead to conclusions that are of importance for gas turbine designers. © 2023, Springer Science+Business Media, LLC, part of Springer Nature.