Dynamic simulation analysis of the bottoming cycle of a 400-MW combined cycle power plant with proportional-derivative control of the drum water level

Abstract

This paper presents the simulation in the transient condition of the bottoming cycle of a 400-MW combined cycle power plant (CCPP), which includes the heat recovery steam generator (HRSG) and triple-pressure reheat steam cycle. The CCPP operates load-following to adjust the varying electric power demand every moment. Thus, an accurate simulation program to calculate the transient behavior of CCPP with load-following operation is required because of unoptimized commercial simulating programs. The pressures, flowrates and temperatures of each heat exchanger and the power outputs of each steam turbine change in part load conditions because of the varying flue gas conditions. A proportional–derivative (PD) controller was used to analyze the water level control in the drums at each pressure with the greatest effect on the stability of the bottoming cycle of the CCPP.