Boiler Parametric Study of Thermal Power Plant to Opproach to Low Irreversibility

Abstract

In this work, in order to reach to low irreversibilities, the energy and exergy have been analyzed in the boiler system of Tabriz power plant. First, it has been done to decrease the irreversibility of system. Second, flow and efficiencies of energy and exergy of the mentioned system have been studied. In the boiler, the energy efficiencies based on lower and higher heating value of fuel are 91.54% and 86.17% respectively. In other hand, the exergy efficiency is 43.98%. Comparing with Rosen and et al., it is demonstrated that, results have a logical agreement with experimental data. Accordingly, the EES used code, have been validated. Furthermore, the gas fired steam power plant efficiency has been increased by the use of irreversibilities reduction and diminution of excess combustion air and/ or the stack-gas temperature. Finally, these have been concluded, overall energy and exergy efficiencies of Tabriz power plant increase 0.497% and 0.46%, respectively when the fraction of excess combustion air decreases from 0.4 to 0.15.Also these efficiencies increase 2.196% nearly when, the stack-gas temperature decreases from 159 to 97 °C.