Effect of Off-design Parameters on the Performance of the Overall Bottoming Cycle in Combined Cycle Power Plant Design

Abstract

This paper presents the thermodynamic analysis of the bottoming cycle in a triple-pressure reheat combined cycle power plant to evaluate the effects of various design parameters on the cycle performance. The important design parameters are three inlet pressures and temperatures in steam turbines, the condenser pressure, and the pinch point temperature of the heat recovery steam generator. These parameters are known to significantly affect the power output of each steam turbine, which influences the overall power output of the combined cycle power plant. The analysis showed the effect of each parameter on the bottoming cycle power output and thermal efficiency. The off-design conditions can significantly affect the cycle performance and this can be used to understand the behavior of the combined cycle plant. The better understanding of the cycle can help to achieve better bottoming cycle designs that can produce higher power outputs and efficiencies.