NH₃/H₂ 预混合气激光点火特性实验

Based on the constant volume combustion chamber,the laser ignition experiments on NH₃/H₂ premixture were carried out under different initial pressure,equivalence ratios and hydrogen mixing ratios. The flame development and minimum ignition energy E_MI under different conditions were analyzed. It is found that with the increase of hydrogen mixing ratio,the influence of buoyancy is weakened and the flame boundary becomes clearer. Increasing pressure can lower the E_MI of mixture,but the E_MI with different equivalence ratio is affected by different pressure. The flame development of pure ammonia is extremely unstable and its E_MI is very high. With the mixing of H₂,the E_MI can be greatly lowered,which can effectively broaden the combustible range of ammonia. When the mixing ratio is 10%,the effect of lowering E_MI is most obvious.