Performance study of reheat gas turbine matched with supercritical once-through HRSG

In order to improve the efficiency and power output of combined cycle gas turbine (CCGT) power plants, a new design of combined cycle with reheat gas turbine (RGT) matched with supercritical Rankine cycle is proposed. Steam cycle is composed of supercritical single pressure level once-through with reheat Heat Recover Steam Generator (SCHRSG). Aspen plus software has been used to calculate the process and to study the performances at different design conditions. The optimization of combined cycle parameters is based on maximizing combined cycle efficiency and has been done using a genetic algorithm (GA). The results are compared with those combined cycles where the gas turbine are not reheated and the HRSG has subcritical three pressure levels with reheat (3HRSG); dramatically advantages in efficiency are highlighted.