The effect of multiple injection on CI engine pollutant emissions and green house gases

Abstract

Today, pollutant emissions coming from diesel engines are one of the major source of air pollution. Stringent pollutant emission regulations place limits on the emissions of diesel engines. Also the future compliance with the new EURO VII regulations is challenging. Manufacturers must come up with novel strategies to reduce ni-trogen oxides (NOx) emissions while fulfilling market demands. In this context, an experimental data were collected from 2100 engine operating point with different injection strategies. Then the results are modelled with robust neural network regression method in AVL Cameo environment. The generated model was run for new 200 test point and results are analyzed. It was observed that when compared to the only single injection strategies, the pilot + main multiple injection reduced NOx by 12 % on total average. On the other hand, the fuel con-sumption is increased by 1.3%. In comparison with the single main injection configuration, the two pilot in-jection + main injection-three stage injection strategy reduced NOx emissions by %16 on total average. However, the fuel consumption increased up by 2.9%. Additionally, based on the findings, the impact of multiple injection on the greenhouse gases (GHG) carbon dioxide (CO2) and nitrous oxide (N2O) is evaluated. Consid-ering, if a zeolite-based selective catalytic reduction (SCR) equipment used in the system it was analyzed that N2O will increase 16% compared to engine out NOx level. Also it was observed that while the GHG effect of CO2 increases with the multiple injection implementation the GHG effect of N2O decreases.