Multi-criteria performance comparison between a novel and two conventional configurations of natural gas – driven combined cycle power plant based on a hybrid multi-objective optimization

Abstract

The performances of three various configurations of combined cycle power plant including gas turbine cycle and steam Rankine cycle (SRC) driven by natural gas are studied and compared from energy, exergy, exergoeconomic, and environmental viewpoints. The first, the second, and the third configurations are respectively combination of simple gas turbine cycle and SRC, single expansion recuperated gas turbine cycle and SRC, and double expansion recuperated gas turbine cycle and SRC. First, the effects of change in two influential parameters consisting of gas turbine inlet temperature and compressor pressure ratio on each system performance are assessed and then, the performances of three studied configurations are compared at the optimal point by employing genetic-fgoalattain hybrid three-objective optimization and considering exergy efficiency, total cost rate, and unit cost of electricity production as objective functions. At the optimal point, the most net power output (249.2 MW) and exergy efficiency (49.6%) are obtained by using configuration 1, while at this point, configuration 1 has the highest total cost rate (10.81 $/S). The best environmental performance and the least total cost rate (6.83 $/S) are related to configuration 3, and using configuration 2 leads to the least unit cost of electricity production (22.66 $/GJ).