Exergoeconomic evaluation of a two-pressure level fired combined-cycle power plant

The application of the exergy and exergoeconomic analysis for energy conversion systems is growing steadily. This analysis is particularly useful for energy conversion systems such as the combined-cycle power plant (CCPP). This paper deals with exergy and exergoeconomic analysis of a combined-cycle power plant with supplementary firing. A process simulation program, IPSE Pro, is used to model the combined-cycle power plant. Exergy and exergoeconomic analysis is carried out by developing a Matlab code. Three configurations of the combined-cycle power plant are investigated and the effect of the configurations of a heat recovery steam generator (HRSG) and performance parameters such as fuel mass flow rate of duct burner and pressure ratio of compressor on combined-cycle performance have been studied. Exergy and exergy cost destruction rates are also calculated. Finally, the cost of generated …

Exergy and exergo–economic evaluation of Isfahan steam power plant

The objective of this paper is to perform the exergy and exergo–economic analysis of Isfahan steam power plant. A simulation program is used for modelling the Isfahan steam power plant in Iran. The exergy balance is used to estimate the exergy destruction in each component of the plant. Moreover, the cost balance equations are solved to determine the cost of exergy destruction in each part of the Isfahan STPP. The highest exergy destruction has mainly occurred in boiler and preheater1&condenser by almost 360.65 MW and 38.81 MW, respectively. In addition, the cost destruction for boiler is about 15090.8 US$/h and for preheater1&condenser is 6056.57 US$/h. Furthermore, the effect of key parameters such as the main steam temperature, reheated steam temperature, condenser pressure and number of the feed water heaters on the cycle performance as well as the final cost of electricity is determined. In particular, by decreasing the condenser, pressure from 0.7 to 0.05 bar the final cost of electricity increases from 7.81 US$/GJ to 9.87 US$/GJ. Accordingly, by increasing the number of the feed water heaters from none to 6, the electricity price will decrease from 19.53 US$/GJ to 8.89 US$/GJ.

Exergy analysis of a 420 MW combined cycle power plant

Combined cycle power plants (CCPPs) have an important role in power generation. The objective of this paper is to evaluate irreversibility of each part of Neka CCPP using the exergy analysis. The results show that the combustion chamber, gas turbine, duct burner and heat recovery steam generator (HRSG) are the main sources of irreversibility representing more than 83% of the overall exergy losses. The results show that the greatest exergy loss in the gas turbine occurs in the combustion chamber due to its high irreversibility. As the second major exergy loss is in HRSG, the optimization of HRSG has an important role in reducing the exergy loss of total combined cycle. In this case, LP‐SH has the worst heat transfer process.
The first law efficiency and the exergy efficiency of CCPP are calculated. Thermal and exergy efficiencies of Neka CCPP are 47 and 45.5% without duct burner, respectively. The results …

Optimization of Combined Cycle Power Plant Using Sequential Quadratic Programming

The thermal-economic optimization of a combined cycle power plant (CCPP) which can provide 140 MW of electrical power is discussed in this paper. The CCPP is composed of a gas turbine cycle (including, air compressor, combustion chamber, gas turbine), heat recovery steam generator (HRSG), steam turbine, condenser system, and a pump. The design parameters of such a plant are compressor pressure ratio (rAC), compressor isentropic efficiency (ηAC) gas turbine isentropic efficiency (ηGT), and turbine inlet temperature (T3), pinch difference temperature (ΔTpinch), steam turbine inlet temperature (Ta), steam turbine isentropic efficiency (ηST), and pump isentropic efficiency (ηPUMP). The objective function was the total cost of the plant in terms of dollar per second, including sum of the operating cost related to the fuel consumption, and the capital investment for equipment purchase and maintenance costs …