Keywords: thermoeconomics, optimisation, combined cycle, CGAM problem, exergy analysis, modelling, optimal design, combined power plants, steam turbines, compressors, sequential quadratic programming, SQP
Modelling and exergoeconomic based design optimisation of combined power plants
In this research a combined cycle power plant (CCPP) which can provide 80 MW of electrical power has been studied. The design parameters of the plant were chosen as: compressor pressure ratio, compressor isentropic efficiency, gas turbine isentropic efficiency, and turbine inlet temperature, pinch difference temperature, steam turbine inlet temperature, steam turbine isentropic efficiency, condenser pressure, and pump isentropic efficiency. In order to optimally find the design parameters a thermoeconomic approach has been followed. An objective function representing the total cost of the plant in terms of dollar per second was defined as the sum of the operating cost related to the fuel consumption, and the capital investment for equipment purchase and maintenance costs. Finally, the optimal values of decision variables were obtained by minimising the objective function using sequential quadratic programming (SQP) for, 50, 60, 70, and 80 MW of net power output.