Numerical study of the influence of particle reaction and radiative heat transfer on the flame velocity of gas/nanoparticles hybrid mixtures

A one-dimensional model was developed to determine the flame velocity of a gas mixture explosion through a two-phase media containing nanoparticles. The mass and energy balances, which take into account a semi-global reaction mechanism with 10 reactions for methane and one carbon nanoparticles combustion, were solved by the finite volume method. The flame propagation model shows a good agreement with commercial software (Premix) to estimate the final temperature, the mass fraction of burnt gases and the flame velocity. For methane/carbon black nanoparticles hybrid mixtures, the numerical model evidences that the insertion of 10 mu m particles (agglomerates diameter) does not influence significantly the flame velocity. Nevertheless, if the particle diameter of the dispersed dust is equals to 75 nm (diameter of the primary particles), a considerable increase of 23% of the flame propagation velocity is obtained when only 6 g m(-3) are added to the combustible mixture. Hence, the results of the numerical model suggest that the heat radiation contribution has a promoting effect on the flame propagation and it is consistent with the experimental increase on the explosion severity for some methane/carbon black hybrid mixtures. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.