Combustion performances of premixed ammonia/hydrogen/air laminar and swirling flames for a wide range of equivalence ratios

Ammonia, a carbon-free source of hydrogen has recently gained considerable attention as energy solution towards a green future. Previous works have shown that adding 30VOL.% hydrogen with ammonia can eradicate the drawbacks of pure ammonia combustion but no study in the literature has investigated this blend across a wide range of equivalence ratios. The present work investigates 70/30VOL.% NH3/H2 blend from 0.55 < Phi < 1.4 for both pre-mixed laminar spherically expanding flames and turbulent swirling flames at atmospheric conditions. A detailed chemistry analysis has been conducted in Ansys CHEMKIN-PRO platform using a chemical reactor network (CRN) model to simulate the swirling turbu-lent flames. NO and NO2 emissions have followed similar bell-shaped trends, peaking at around Phi = 0.8, while N2O emission rises at lean conditions (Phi < 0.7). The results indicate that Phi = 1.2 is the optimum equivalence ratio with reduced NOX emissions and some ammonia slip.(c) 2022 The Author(s). Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC. This is an open access article under the CC BY license (http://creativecommons.org/ licenses/by/4.0/).

Automated summary

This study investigates the combustion characteristics of a 70/30VOL.% NH3/H2 blend at different equivalence ratios and finds that Phi = 1.2 is the optimum equivalence ratio with reduced NOX emissions and some ammonia slip.