Simulation and Optimization Research of Reaction Kinetic Mechanism, Thermal and Combustion Process and Pollutant Generation and Aftertreatment of Ammonia–Hydrogen Engine

Focusing on efficiency and emissions, this study investigates the reaction mechanism, thermal and combustion processes, pollutant generation, and aftertreatment of ammonia–hydrogen engines. It is found that increasing hydrogen fraction, raising unburned gas temperature, reducing reaction pressure, and proper concentrated combustion can enhance laminar burning velocity and improve combustion characteristics, with hydrogen fraction exerting the most significant impact on engine performance. Within a specific range, appropriately increasing hydrogen fraction can reduce NOx emissions. The optimal hydrogen energy fraction ranges 35%–45% under medium‐high speeds (1400–1900 RPM); it can be moderately increased to 45%–50% with small spark advance angles, while decreasing to 30%–35% with large spark advance angles.