Multi-Objective Optimization of an Inlet Air-Cooled Combined Cycle Power Plant

Abstract

The present work aims to investigate the effect of inlet air cooling in conjunction with other input parameters on the exergetic performance of combined cycle power plants (CCPP). To mitigate the adverse effects of high ambient temperature on performance, the CCPP has been equipped with an inlet air cooler, which lowers the air temperature at the inlet of the compressor. Under a specific combination of input parameters, the analysis revealed a maximum increase in net specific work, efficiency, and exergetic efficiency of 14.16%, 3.93%, and 5.65%, respectively. Moreover, the effects of multiple input parameters were analyzed individually and in combination. This was done in order to identify the most influential exergy-affecting parameters for the CCPP, which turned out to be the degree of cooling, pressure ratio, and turbine inlet temperature. The simulated model is then subjected to two sets of multi-objective optimization using a genetic algorithm, considering the above parameters as design variables. According to the Pareto set of optimal solutions, cooling the inlet air by 16.5 K results in the highest net-specific work output and increased exergy destruction. Increased exergy destruction, on the other hand, is undesirable. However, if the cost of power per unit is high, this could be economically advantageous.