Energy and Exergy Analysis of an Enhanced Combined Cycle Power Plant With Steam Injection

With the growing global demand for electricity and the recent focus on decarbonization trends in power generation, transforming gas turbine power plants into combined cycles has become a coherent strategy to enhance the overall energy output while reducing related emissions. In this study, a comprehensive analysis based on the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1^{\text {st }}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2^{\text {nd }}$</tex> laws of thermodynamics on each component of the proposed combined cycle power plant has been conducted. The energy and exergy analysis demonstrates how injecting steam into the combustion chamber of the gas turbine cycle affects the overall performance of the power plant. By conducting this, the precise determination of exergy destruction and efficiency in each component can be obtained separately. Additionally, a sensitivity analysis has been conducted to further evaluate the influence of control variables in the Bryton cycle, such as the pressure ratio and turbine inlet temperature on the performance of the combined cycle and gas turbine cycle. The results indicate that increasing the steam injection fraction and turbine inlet temperature enhances the combined cycle total energy and exergy efficiencies while raising them to 53.06 % and 51.47 %, respectively. Also, a 3.53 % rise in the overall output of the power plant is evaluated.