The Exergy Losses Analysis in Adiabatic Combustion Systems including the Exhaust Gas Exergy

• Published in: Entropy (Basel, Switzerland) Vol. 24; no. 4; p. 564
• Main Authors: Agrebi, Senda, Dreßler, Louis, Nishad, Kaushal
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 18.04.2022; MDPI
• Subjects: Adiabatic flow; Chemical reactions; Chemistry; Combustion chambers; Deformation; Destruction; Energy efficiency; entropy generation analysis; Environmental impact; Eulerian stochastic field method; Exergy; Exhaust gases; exhaust gases exergy; Exhaust systems; FGM; flames E and F; Gases; Investigations; Scalars; Simulation; Tabulation; Variables; Viscosity; entropy generation analysis; exhaust gases exergy; Eulerian stochastic field method; FGM; flames E and F
• ISSN: 1099-4300; 1099-4300
• DOI: 10.3390/e24040564

The entropy generation analysis of adiabatic combustion systems was performed to quantify the exergy losses which are mainly the exergy destroyed during combustion inside the chamber and in the exhaust gases. The purpose of the present work was therefore: (a) to extend the exergy destruction analysis by including the exhaust gas exergy while applying the hybrid filtered Eulerian stochastic field (ESF) method coupled with the FGM chemistry tabulation strategy; (b) to introduce a novel method for evaluating the exergy content of exhaust gases; and (c) to highlight a link between exhaust gas exergy and combustion emissions. In this work, the adiabatic Sandia flames E and F were chosen as application combustion systems. First, the numerical results of the flow and scalar fields were validated by comparison with the experimental data. The under-utilization of eight stochastic fields (SFs), the flow field results and the associated scalar fields for the flame E show excellent agreement contrary to flame F. Then, the different exergy losses were calculated and analyzed. The heat transfer and chemical reaction are the main factors responsible for the exergy destruction during combustion. The chemical exergy of the exhaust gases shows a strong relation between the exergy losses and combustion emission as well as the gas exhaust temperature.