Energy‐exergy performance assessment with optimization guidance for the components of the 396‐MW combined‐cycle power plant

Abstract

Abstract In this study, energy‐exergy analysis is performed for the gas‐fired combined‐cycle power plant which will be constructed in Kuantan and Kapar in the Malay Peninsula in 2020. The main objectives of this current study are first and second law evaluation of the powerplant's main components consisting of the gas turbine unit, condenser, heat recovery steam generator, and triple‐pressure steam turbines. By energy‐exergy analysis, we can not only evaluate the exact magnitude of exergy destruction and efficiency in each component separately but analyze either major or trivial effects of environment condition variations on plant components. Performance effects are also pinpointed when the pressure ratio, reference temperature, HPT and condenser pressure, reheating and stack temperature change. In the current investigation, more than 808 MW of exergy destruction to the environment mainly occurs in the gas turbine cycle with around 83.79% of total exergy destruction, followed by HRSG (11.3%), steam turbines (roughly 2.58%), and condenser (2.54%). Additionally, exhaust gas fractions from the gas turbine across the combustor are calculated as well wherein the average molar fraction of nitrogen, oxygen, carbon dioxide, and water vapor is calculated to be 76.42%, 17.57%, 1.37%, and 4.64%, respectively. In conclusion, several constructive possibilities for CCPP’s performance development based on the obtained results are introduced. With regard to the construction of this project in 2020, energy‐exergy assessment, as well as optimization guidance, can be worthwhile for better modifying some operating conditions and taking advantage of the trivial destruction rate simultaneously.

Keywords

• combined‐cycle power plant
• combustion chamber
• energy
• exergy
• gas turbine
• heat recovery steam generator