Numerical simulation of a spark ignition ammonia marine engine for future ship power applications

Given the current state of global carbon emissions, China has proposed the objectives of achieving carbon peaking by 2030 and carbon neutrality by 2060. To meet the requirement of zero -carbon and achieve the application of pure ammonia fuel in low -speed two-stroke marine engines, this paper proposes the Groove Diversion -Assist Ignition (GDAI) combustion system, which can effectively control the temperature, fuel distribution, and flow rate in the spark plug region near the top dead center and finally achieve the spark ignition of pure ammonia without any change in compression ratio and scavenging temperature. At the same time, the boundary conditions for the ignition of ammonia fuel have also been studied. The results show that enhancing the initial temperature can alleviate the requirement for spark ignition energy, and a minimum energy level of 75 mJ remains necessary for effective spark ignition of ammonia. Furthermore, the utilization of spark ignition of ammonia fuel can achieve a maximum thermal efficiency of 51.32%, representing a 2.8% increase in overall thermal efficiency compared to the diesel mode. Additionally, the application of ammonia fuel can relief the NOx emissions compare to diesel fuel, which provides a new and effective utilization way for the application of ammonia fuel on the marine engine.