氨氢燃料激光点火特性实验和模型研究

Based on the constant volume combustion chamber, laser ignition experiments were carried out on ammonia-hydrogen mixture with different hydrogen mixing ratio (0~20%), different equivalence ratio (0.6~1.4) and different initial pressure (0.1~0.4MPa). The flame development morphology, probability of ignition and minimum ignition energy changes under different conditions were analyzed. At the same time, a minimum ignition energy optimization model is proposed which can directly predict the energy under different working conditions. The results show that increasing the hydrogen ratio and initial pressure can significantly improve the flame stability and reduce the minimum ignition energy. The reduction effect is most obvious when the hydrogen ratio is 10% or the initial pressure is 0.2MPa, but the reduction range will gradually decrease with increasing the hydrogen ratio or pressure. The effect of equivalence ratio on flame stability and minimum ignition energy is non-monotonic. When equivalence ratio is 0.8, the minimum ignition energy reaches the minimum value. The optimized model can predict the minimum ignition energy well under all working conditions, but the accuracy of the prediction results is still affected by the function properties.