Exergy and exergoeconimic analysis and multi-criteria optimization of 1 MW installed CCHP system (a case study in Kashan University)

Abstract

The present study deals with exergy and exergo-economic evaluation of a 1 MW combined cooling, heat and power (CCHP) system, composed of a natural gas prime mover internal combustion engine located in the main campus of the University of Kashan, Kashan, Iran. Using appropriate linking between engineering equation solver (EES) and MATLAB software, thermal and economic modelling and multi-criteria optimisation (MCO) have been performed. The optimisation results showed that the minimum total exergy destruction rate occurs for the exhaust gas extraction factor of 0.68, which causes $33.52/h total cost rate. For this case, among all of the system components the highest exergy destruction rate of 1,700 kW belongs to the engine. In addition, the results of the genetic algorithm-based multi-objective optimisation represented that the optimisation causes $2.68/h decrease in total cost rate and reduction of 4512 kW in exergy destruction rate.