氨/氢气湍流预混火焰传播特性实验研究

As a carrier of hydrogen, ammonia is a carbon-free fuel with great potential. Using ammonia as the main fuel, the turbu-lent flame propagation characteristics of ammonia/hydrogen mixtures were experimentally studied with a turbulent constant volume combustion bomb under various equivalence ratios, hydrogen blending ratios, and turbulence intensities. The high-speed Schlieren technique was used to study the turbulent flame propagation images based on the measurement of turbulent flame characteristics. The turbulent flame velocity was obtained and its normalized fitting formula was derived. The turbulent flame propagation characteristics of ammonia and ammonia/hydrogen were analyzed. Results show that hydrogen addition can significantly improve the stability of the ammonia/hydrogen flame. With the increase in the hydrogen blending ratio, the turbulent burning velocity was significantly increased, and the combustion intensity was enhanced. With the increase in flame radius and turbulence intensity, the flame wrinkle ratio gradually increased, and the turbulent combustion was more intensive. The Reynolds number of flame can be used to better normalize the turbulent burning velocity under different equivalence ratios and turbulence intensities, and the power exponents after fitting were all about 0.5, showing that the turbulent flame was under self-similar accelerative propagation.