Study on flame stability and flame height in oxygen-enriched ammonia/N₂/O₂ laminar diffusion flame

Abstract

Ammonia is regarded as one of the alternative fuels because the physical properties of Ammonia are suitable for transportation and storage as a "hydrogen carrier". Also, a large amount of ammonia can be produced easily through the Haber-Bosch process with low price. To use ammonia as a fuel, it is necessary to get the knowledge of fundamental combustibility of ammonia. Flame stability and flame height are important factors when ammonia is used as a fuel in industry. Ammonia laminar diffusion flame is difficult to be stable under atmospheric oxidizer (O2 21%) of room temperature. In this study, therefore, the oxygenenriched combustion was applied to make the stable ammonia laminar diffusion flame. The burner lip was focused to make the more stable ammonia laminar diffusion flame and the dependences of O2 concentration and burner lip on flame stability were investigated. Flame height was also measured under the conditions that the ammonia laminar diffusion flame were formed stably. The flame height of ammonia laminar diffusion flame was compared with that of methane laminar diffusion flame. Results showed that the stability of the ammonia laminar diffusion flame was improved in thick burner lip condition. Also, the flame height of ammonia laminar diffusion flame was shorter than that of methane laminar diffusion flame.