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

Abstract

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 stackgas temperature decreases from 159 to 97 °C.

Energy and Exergy Analysis of a Coal Fired Boiler of 250MW Thermal Power Plant

“…P. S. Hada and I. H. Shah [10] in a first law and second law analysis of a lignite fired boiler used in a 30MW thermal power plant found the two efficiencies as 85.52% and 33.73%. S. Arefdehgani and O. K. Sadaghiyani [11] in a boiler parametric study of a gas fired steam power plant found the boiler energy efficiency as 91.54% and 86.17% based on lower and higher heating values respectively which were in logical agreement with experimental data. They studied the effect of several measures and concluded that by decreasing excess air fraction from 0.4 to 0.15 energy and exergy efficiency of the plant increases by 0.497% and 0.46% respectively.…”

“…Now with reference to boiler schematic diagram shown in Fig.1 E in = m 9 h 9 + m 11 h 11 (10) And total energy of outgoing mixture, E out = m g h g (11) Where m g and h g are the mass flow rate and specific enthalpy of hot combustion product i.e. flue gas respectively.…”

Thermodynamic Evaluation Based Exergy and Energy Analysis of Existing Indramayu Coal-Fired Power Plants

“…In addition, excess air also affects the quality of combustion [13]. Arefdehgani, 2015, stated that by reducing excess air in combustion, increasing the temperature of combustion products, and decreasing the value of excess air from 0.4 to 0.15, the energy and exergy efficiencies increase 0.497% and 0.46%, respectively [18]. Rosen & Tang, 2008, reported that Energy and exergy efficiency increases by 3.5% when the stack-gas temperature decreases from 149°C to 87°C [19].…”