Keywords: exergy analysis, optimisation, decision variables, genetic algorithms, thermoeconomics, exergy destruction, thermodynamic modelling, exergoeconomics, optimisation, gas turbines, absorption chiller, thermodynamics, design parameters, unit cost of fuel, turbine output power
Modelling and exergoeconomic optimisation of a gas turbine with absorption chiller using evolutionary algorithm
In this paper, thermodynamic modelling of a gas turbine cycle with absorption chiller is performed. A thermoeconomic approach is utilised to find the most optimal values of design parameters for practical applications. Some design parameters considered are compressor pressure ratio, compressor isentropic efficiency, gas turbine isentropic efficiency, gas turbine inlet temperature, HRSG pressure, pinch point temperature, absorption generator temperature, absorption evaporator temperature and absorption condenser temperature. The objective function considered for the optimisation purpose is the summation of the fuel cost, purchase cost of each component and the total cost rate of exergy destruction. A sensitivity analysis of the changes in the design parameters with respect to the unit cost of fuel and gas turbine output power is also performed. The results show that increase in the unit cost of fuel tends to decrease in other term of objective function. Moreover, increase of the unit cost of fuel leads to elect the equipment in the way their cost of exergy destruction reduces.