氨/氢气高温自着火特性实验和理论研究

To understand the influence of hydrogen addition on the auto-ignition characteristics of ammonia fuel, the experimental, simulation and theoretical studies on the ignition delay times of ammonia/hydrogen mixtures were carried out. The ignition delay times of stoichiometric ammonia/ hydrogen mixtures were measured in a shock tube at 1 MPa, 1124∼1695 K, and 0%, 5%, 30% and 70% hydrogen blending ratio. Based on the experimental data, the prediction performances of existing ammonia kinetic models on ignition delay times were evaluated, the chemical kinetic interaction of ammonia/hydrogen ignition was analyzed by using the Otomo model. It is found that the ignition delay of ammonia decreases nonlinearly with the increase of hydrogen blending ratio; the chemical equilibrium of NH₃ + H ⇔ NH₂ + H₂ can be reversed by 5% hydrogen doping; with the increase of hydrogen mixing ratio, the inhibition effect of ammonia -related reaction on ignition is enhanced, and the promotion effect of hydrogen addition on the ignition delay time is weakened.