EXERGETIC EVALUATION OF SINGLE PRESSURE HRSG BASED COMBINED CYCLE GAS POWER PLANT

Abstract

The increasing demand of power has made the power plants of scientific interest, but most of the power plants are designed by the energetic performance criteria based on first law of thermodynamics only. The real useful energy loss cannot be justified by the fist law of thermodynamics, because it does not differentiate between the quality and quantity of energy. The exergy analysis (second law analysis) is used for providing information about the losses qualitatively as well as quantitatively along with their locations. Exergetic (thermodynamic) optimization improves the performance of a system by reducing the exergetic inefficiencies (exergy destruction and exergy losses) and increasing exergetic efficiency. In this analysis shows exergy efficiency is less at each and every point of unit equipment’s. Also presents major losses of available energy at combustor, HRSG and gas turbine. The primary objectives of this work is to analyse the system components separately and to identify and quantify the sites having largest energy and exergy losses at different load. A program code is established using MATLAB software to perform the calculations required for the exergy plant analysis considering real variation ranges of the main operating parameters such as pressure ratio, air fuel ratio and inlet temperature. The effects of theses parameters on the system performances are investigated.