含水氨氢燃料燃烧特性和污染物生成机理数值模拟分析

Numerical Simulation and Analysis of Combustion Characteristics and Pollutant Generation Mechanism of Aqueous Ammonia-hydrogen Fuel

摘要:

氨氢融合燃料是交通领域实现“双碳”目标首选的可再生零碳燃料。以点火延迟时间为特征参数，优选多工况下泛用性更好的Stagni机理，探究不同温度（900~1 400K）、压力（10~60bar）、掺氢比（0~50%）、当量比（0.6~1.4）和掺水比（0~60%）对燃烧特性的影响，确定10%的掺水比为平衡燃烧和污染物生成的最佳比例。结果表明基元反应（R5、R85、R90、R91、R144）是影响燃烧的主要反应，且R5和R38、R74、R172对水的敏感性相反。NH₃→NH₂→NH→N→NO是NO生成的主要路径，水的添加抑制了NH₂等中间产物的生成，从而降低NO的生成。

Abstract:

Ammonia-hydrogen fusion fuel is the preferred renewable zero-carbon fuels for achieving the “dual-carbon” target in the transport sector.The ignition delay time was used as a characteristic parameter to select the Stagni mechanism with better general applicability under multiple operating conditions， and the effects of different temperatures （900-1 400 K）， pressures （10-60 bar）， hydrogen blending ratios （0-50%）， equivalence ratios （0.6-1.4） and water blending ratios （0-60%） on the combustion characteristics were investigated， and the optimal ratio of 10% water blending was determined to balance the combustion and the pollutants generation. It was determined that 10% water blending ratio was the optimal ratio for balanced combustion and pollutant generation. The results showed that the primitive reactions （R5， R85， R90， R91， R144） were the main reactions affecting the combustion， and the sensitivities of R5 and R38， R74， R172 were opposite to that of water. NH₃→NH₂→NH→N→NO was the main pathway of NO generation， and the addition of water suppressed the generation of intermediate products such as NH₂， thus decreasing the NO generation.