The Performance Analysis of a Combined Power Plant Implementing Technologies for Enhancing Power and Efficiency

Combined Cycle Power (CCP) plant using Liquefied Natural Gas (LNG) plays a key role in electric supply including nuclear and coal power generation systems. There is growing demand for enhancing power and efficiency of existing CCP plants. Typically, the power reduction of gas turbine during summer can be recovered if gas turbine intake cooling system can be implemented in existing LNG based CCP plants. Possible approaches for power and efficiency enhancement are being widely studied in global gas turbine society. The present study aims to investigate net benefit of implementing selected technologies for enhancing power and efficiency of an existing LNG based CCP. For a comparative study, selected technologies such as (1) gas turbine intake cooling system, (2) wet cycle (steam injection), and (3) turbine cooling air precooling are implemented to Busan LNG based CCP plant, Republic of Korea. The complete CCP plant is modeled using Gatecycle and its validation against field operation data showed the differences in the generated power and efficiency at the base load condition within 0.5% and the difference in the turbine inlet temperature value less than 3%. Among the selected technologies, the wet cycle (steam injection) showed the most promising result. Its system composition is relatively simple in comparison to the other technologies. Furthermore, it is advantageous to use within a reasonable limit when higher power is required for peak demand of electric power.