Characteristics of hydrogen-ammonia-air cloud explosion

The main task of this work is to study the hydrogen-ammonia -air cloud explosion characteristics. The flame behavior and explosion pressure are obtained experimentally by changing equivalence ratio (ER) and ammonia fraction (AF). Then the correlation between flame behavior and maximum explosion pressure is revealed. Finally, the thermal, diffusion and chemical factors affecting laminar burning velocity (LBV) are analyzed. The results indicated that averaged flame propagation velocity (AFPV) and maximum explosion pressure (MEP), become decreased continuously with increasing AF, become increased firstly and then decreased with increasing ER. Maximum value of both AFPV and MEP of AF = 0.1, AF = 0.3, AF = 0.5 and AF = 0.7 is reached at ER = 1.4, ER = 1.2, ER = 1.0 and ER = 1.0. the MEP could be underestimated and overestimated by laminar and turbulent flame model. The MEP is largely affected by LBV especially when the flame instabilities are ignored. With increasing AF, the reduction of adiabatic flame temperature and thermal diffusivilty contributes to the LBV reduction. With increasing ER, the main factor affecting LBV is the generation and consumption of H radical. (C) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.