作为化石燃料的替代品,人们对在燃烧系统中使用氨越来越感兴趣,特别是在内燃机中。作为氢的有力竞争者,它有各种优点。然而,为了保持燃烧稳定性,仍然需要添加诸如氢气的点火促进剂。由于使用氨的发动机也遭受高NOx排放,在这项研究中,数值研究了添加不同气体对氨氢双燃料发动机性能和排放的影响。基础发动机是柴油发动机,其参数习惯于以氨-氢作为燃料运行。氢气在进气阶段以180度曲柄角(CAD)通过进气口喷射,并与气缸充气混合。在350-370CAD下将氨直接注入气缸中。不同的气体,包括氩气,氮,二氧化碳,和氧气,之前在不同的曲轴转角注入气缸,during,和氨注入后(330-350CAD,350-370CAD,和370-390CAD)。准备了MATLAB代码来求解控制方程,燃烧机制在Cantera实施。结果表明,在氨喷射定时之前或同时添加CO2对缸内压力峰值以及NO和NO2排放产生不利影响。O2的添加对排放有负面影响。在氨注入(350-370CAD)的同时添加N2和Ar可以减少NO和NO2排放,而不会显著影响缸内压力和温度峰值。
As an alternative to fossil fuels, there is growing interest in using ammonia in combustion systems, particularly in internal combustion engines. As a competent competitor to
hydrogen, it has various advantages. However, adding an ignition promoter such as
hydrogen is still necessary to maintain combustion stability. Since the engine using ammonia also suffers from high NOx emissions, in this study, the effects of adding different gases on the performance and emissions of an ammonia-
hydrogen dual-fuel engine were numerically investigated. The base engine was a diesel engine whose parameters were accustomed to running with ammonia-
hydrogen as fuel.
Hydrogen was injected via the port in the intake stage at 180 crank angle degrees (CAD) and mixed with the cylinder charge. Ammonia was directly injected into the cylinder at 350-370 CAD. Different gasses, including argon, nitrogen, carbon dioxide, and oxygen, were injected into the cylinder at various crank angles before, during, and after ammonia injection (330-350 CAD, 350-370 CAD, and 370-390 CAD). A MATLAB code was prepared to solve the governing equations, and the combustion mechanism was implemented in Cantera. The results showed that adding CO2 before or concurrent with the ammonia injection timing had undesirable impacts on the peak in-cylinder pressure and NO and NO2 emissions. The O2 addition had a negative on the emissions. Adding N2 and Ar concurrently with the ammonia injection (350-370 CAD) could diminish NO and NO2 emissions without drastically affecting the peak in-cylinder pressure and temperature.