Effect of Diesel-Ignited Ammonia/Hydrogen Mixture Fuel Combustion on Engine Combustion and Emission Performance

• This paper aims to study the combustion and emission performance of ammonia fuel mixed with a certain proportion of hydrogen engines under the mode of diesel ignition. • Mixing hydrogen can improve the flame propagation speed during ammonia combustion, promote the combustion reaction in the cylinder, and eliminate the ammonia escape phenomenon caused by an excessive amount of ammonia. • The research results can promote the practical application of NH3/H2 fuel in high-pressure common rail compression ignition diesel engines, and also promote the development of hydrogen in compression ignition engines, It is of great significance to achieving the zero carbon emission goal of carbon neutrality. • This paper aims to investigate the engine performance of ammonia/hydrogen mixed fuel in diesel ignition mode. The mixed hydrogen improves the flame propagation speed during ammonia combustion and eliminates the ammonia escape phenomenon caused by excessive ammonia. The research results are of great significance for achieving the goal of carbon neutrality and zero carbon emissions. To reach zero carbon emissions and meet carbon neutrality targets, ammonia is one of the most promising zero-carbon fuels. However, ammonia escapes significantly when too much ammonia is blended. Therefore, a certain percentage of hydrogen is blended with the ammonia, which can promote in-cylinder combustion reactions. This paper aims to study the effect of varying ammonia blending hydrogen ratio on in-cylinder explosion pressure, temperature, power, fuel consumption rate, CA50, ammonia escape ratio, hydrogen escape ratio, NO x , CO 2 and soot emissions under two ignition modes when the diesel engine speed of 1800 r/min at rated operating conditions in a high-pressure common rail diesel engine, and set nine groups of hydrogen blending ratios from 10% to 90% for diesel ignition. The results show that: when the hydrogen blending ratio is 30% compared to 0, the in-cylinder explosion pressure increases by 10.7%, the power increases by 1.8%, the fuel consumption rate decreases by 0.3%, the ammonia escape ratio decreases by 99.1%, the NO x emissions increase by 58.8%, the CO 2 increases by zero, the soot and HC emissions improvements, and the overall performance of the diesel engine is improved after hydrogen blending combustion. To achieve the net-zero carbon emission goal of carbon neutralization, a small amount of diesel ignition direct injection ammonia blended with 30% hydrogen is the better solution.