The study of solid flame model of diffusion jet flame for the ammonia and propane mixed gas under the inclined ceiling

Abstract

In order to solve the environmental pollution and energy dilemma, the ammonia has been considered as a new fuel and a carbon-free hydrogen carrier, which can be blended into the traditional hydrocarbon fuels. In this study, the evolution of flame emissivity, view factor and radiative heat flux have been investigated under different mass flow rates of ammonia and propane, and inclined angle of ceiling. A radiation prediction model of ammonia-propane mixed gas jet flame under inclined ceiling with different inclined angles has been developed. This prediction model can accurately describe the flame morphology and simplify the calculations, and consider the influence of mixing ratio on combustion reaction. The experimental results indicated that the flame emissivity, view factor, and radiative heat flux decrease with the increase of ammonia concentration. The prediction error of the traditional model will be enlarged with the increase in the inclined angle of ceiling. The modified model added the undersurface of ceiling jet flame, which reduces the prediction error from 25 % to 14 %. These prediction models are helpful in predicting the thermal radiation of jet flame under inclined ceiling.