Natural gas/diesel dual-fuel engine has become an urgent need to alleviate the energy crisis and reduce emissions. As an additive, reforming gas can improve the combustion process of dual-fuel engines because it improves the combustion rate and compensates for the low reactivity of natural gas. Therefore, it is of great significance to study the ignition characteristics of natural gas diesel blends by adding H₂ and syngas. Based on ANSYS Chemkin 17.0 software, the ignition delay time was solved by a closed uniform model. The effects of H₂ and syngas on the ignition performance of a natural gas/diesel engine were studied. The results showed that the ignition delay time of the methane/n-heptane mixture was prolonged after adding H₂ in the range of medium and low temperatures. This was due to the fact that reaction R3 (OH + H₂ = H + H₂O) was an endothermic reaction, which consumed OH radicals and inhibited the ignition process. In the high-temperature range, adding H₂ reduced the ignition delay time of the mixture system, which was because of the significant increase in the sensitivity coefficients of R1(H + O₂ = O + OH) and R3 and the generation of OH radicals. Therefore, the reduction in ignition delay caused by H₂ addition in the high-temperature regions was mainly attributed to R3 and R1. In syngas, CO reduced the ignition delay time of methane/syngas/n-heptane. However, the addition of CO could reduce the importance of R3 in the reaction process—resulting in the weakening of the influence of H₂ on ignition delay. This study can expand the theoretical basis of ignition characteristics of methane/n-heptane mixture with H₂ and syngas under dual-fuel engine-relevant conditions.

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双燃料发动机相关条件下重整气体对点火特性影响的数值研究

天然气/柴油双燃料发动机已成为缓解能源危机和减少排放的迫切需要。作为添加剂，重整气可以改善双燃料发动机的燃烧过程，因为它提高了燃烧速率并弥补了天然气的低反应性。_{因此，研究添加H 2}和合成气的天然气柴油混合物的着火特性具有重要意义。基于ANSYS Chemkin 17.0软件，采用封闭均匀模型求解点火延迟时间。研究了H ₂和合成气对天然气/柴油发动机点火性能的影响。结果表明，加入H _{2后，甲烷/正庚烷混合物的着火延迟时间延长。}在中低温范围内。这是因为反应 R3 (OH + H ₂  = H + H ₂ O) 是一个吸热反应，它消耗了 OH 自由基并抑制了点火过程。在高温范围内，加入H ₂降低了混合系统的着火延迟时间，这是由于R1（H + O ₂  = O + OH）和R3的灵敏度系数显着增加以及OH的生成激进分子。_{因此，H 2}引起的着火延迟减少高温区的增加主要归因于 R3 和 R1。在合成气中，CO 减少了甲烷/合成气/正庚烷的着火延迟时间。然而，添加 CO 会降低 R3 在反应过程中的重要性，从而削弱 H ₂对点火延迟的影响。该研究可以扩展双燃料发动机相关条件下甲烷/正庚烷混合物与H _{2和合成气的点火特性的理论基础。}