4E modeling and multi-criteria optimization of CCHPW gas turbine plant with inlet air cooling and steam injection

An integrated plant for production of combined cooling, heating, power and water (CCHPW) has been investigated here. The plant included a gas turbine (with steam injection in combustion chamber), an HRSG producing steam (with reheat and dual drum pressures) and absorption refrigeration system (for both space and inlet air cooling). Four E (Energy, Exergy, Environmental, and Economic) modeling and optimization of an integrated CCHPW plant was performed to evaluate the optimum values of nine design parameters. Multi-objective optimization of CCHPW plant using genetic algorithm method with exergy efficiency and total annual cost (TAC) of system as two objective functions was applied. Results showed that at the optimum design point, compressor inlet air temperature was 18.5 °C and steam injection into combustion chamber of gas turbine was 1.8%. The exergetic efficiency and TAC of integrated CCHPW plant at the selected optimum point was 30.7% and 28.545 million dollars, respectively. The payback period of about 4.38 years was estimated for the analyzed plant at the optimum design point. Finally, the sensitivity analysis of change in capital investment and fuel costs on the optimal values of design parameters was also performed and presented.