Exergy analysis of the dual pressure HRSG for varying physical parameters

Abstract

Heat recovery steam generator (HRSG) is used to capture the heat of gas turbine exhaust gases for generating steam to run the steam turbine in gas/steam combined cycle power plant (CCPP). The performance of HRSG affects the steam turbine output and thus the overall combined cycle performance. The present study considers operating conditions of a 663MW, combined cycle power plant at Auraiya (U.P.), India for carrying out the exergy based investigation of a dual pressure HRSG. Different physical parameters of HRSG such as fin height, fin density and fin thickness are varied for analyzing exergy loss and exergy efficiency at different steam generation pressures. The exergy analysis shows how the exergy losses get lowered for LP evaporator and the exergy efficiency improves in LP economizer for higher fin heights and fin densities.