Exergoeconomic Analysis of a Combined Cycle of Three Levels of Pressure
This paper presents an exergoeconomic analysis of the combined cycle power plant Tuxpan II located in Mexico. The plant is composed of two identical modules conformed by two gas turbines generating the required work and releasing the hot exhaust gases in two heat recovery steam generators. These components generate steam at three different pressure levels, used to produce additional work in one steam turbine. The productive structure of the considered system is used to visualize the cost formation process as well as the productive interaction between their components. The exergoeconomic analysis is pursued by 1) carrying out a systematic approach, based on the Fuel-Product methodology, in each component of the system; and 2) generating a set of equations, which allows compute the exergetic and exergoeconomic costs of each flow. The thermal and exergetic efficiency of the two gas turbines delivering 278.4 MW are 35.16% and 41.90% respectively. The computed thermal efficiency of the steam cycle providing 80.96 MW is 43.79%. The combined cycle power plant generates 359.36 MW with a thermal and exergetic efficiency of 47.27% and 54.10% respectively.