Entropy generation analysis of H2/air premixed flame in micro-combustors with heat recuperation

• The thermodynamic irreversibility in micro-combustion is analyzed.
• The effects of flow velocity and H2/air equivalence ratio are investigated.
• The effect of heat recuperation on entropy generation is studied.
• 1.6% of the total exergy loss can be saved by using the heat recuperation.

A theoretical analysis on entropy generation in H2/air premixed flame is presented. The entropy transport equation is employed to evaluate the entropy generation rate caused by various irreversible processes such as chemical reaction, conduction, mass diffusion and viscous dissipation. The model is applied for premixed flames in a confined geometry under different inlet flow velocity levels and H2/air equivalence ratios. Comparisons between the combustors with and without heat recuperation are done in terms of specific and total rate of entropy generation. It is found that a higher flow velocity and higher H2/air equivalence ratio will increase the rate of entropy generation. The usage of heat recuperator decreases the rate of entropy generation which results in lower exergy loss.