Effects of Combustion Characteristic Parameters on Emission Performance in Ammonia-hydrogen Internal Combustion Engine

Under the background of the global dual carbon target, ammonia and hydrogen as the carbon-free fuel, have become a research hotspot for internal combustion engines. The existing researches mainly focus on the combustion characteristics influenced by equivalent ratio, hydrogen jet ignition and so on, while the relationship between combustion and emission characteristics should be also paid more attention. In this paper, the impact of combustion characteristic parameters on engine emissions is investigated by GT-power software. The simulation model is based on a single cylinder active pre-chamber engine and Wiebe combustion model. Meanwhile, combustion characteristic parameters, in terms of CA10,CA50 and CA90 are set referred to the research of hydrogen jet ignition ammonia-hydrogen internal combustion engine. The results show that CA10, CA50 and CA90 could significantly affect the concentration of N2O, NH3 and NOX emissions in different ways. The concentrations of N2O, NH3 emissions are signally influenced by CA50 and CA90, both of them decrease as CA50 and CA90 are delayed. Because the generation of N2O and NH3 emission is positively related to low combustion temperature duration which is mostly decided by CA50 and CA90. Relatively, as the production of high combustion temperature duration, NOX emission shows the strong connection with CA10. The concentration of NOX emission is rapidly decreased as CA10 is delayed which reduce the combustion temperature and high temperature duration. When CA10 is -7°CA ATDC,CA50 is 5°CA ATDC and CA90 is 15°CA ATDC, the lowest concentrations of N2O, NH3 emissions are observed. When CA10 is -9°CA ATDC,CA50 is 10°CA ATDC and CA90 is 25°CA ATDC, the lowest concentration of NOX emission is observed. The above results provide a theoretical basis for the emission control of ammonia-hydrogen internal combustion engines from the perspective of combustion characteristic parameters.