Study on the effect of turbulent jet combustion chamber on combustion characteristics at different ammonia energy ratio and optimization of an ammonia-diesel dual-fuel engine

In order to investigate the impact of turbulent jet combustion chamber (TJCC) on the combustion and emission characteristics of an ammonia-diesel dual-fuel (ADDF) engine and optimize the injection strategy of TJCC to achieve efficient and clean combustion at high ammonia energy ratio (AER), this paper established a three-dimensional simulation model. The findings demonstrated that raising the AER from 50% to 90% under heavy load conditions resulted in an increase in ITEg from 47.3% to 50.6% due to more uniform fuel distribution in the cylinder. Additionally, there was a significant reduction of over 70% in greenhouse gas (GHG) emissions, along with a decrease in the amount of diesel. The turbulent jet from TJCC caused the turbulence kinetic energy to rise in both intensity and range, which improved the mixing rate of diesel-ammonia-air and the flame propagation. The ITEg increased by 3.3%, 2%, and 0.7%, respectively, under the impact of the turbulent jet when AER was 50%, 70%, and 90%, respectively, compared to not injecting diesel in the TJCC. Finally, the ITEg reached 51.9% and unburned NH3, NO, and NO2 emissions were significantly reduced when AER was 90% and 10 mg of diesel was injected at 4 degrees CA ATDC in the TJCC.