Comparison of intake and exhaust throttling for diesel particulate filter active regeneration of non-road diesel engine with mechanical fuel injection pump

Diesel particulate filter regeneration using intake and exhaust throttling is technically simple and economically efficient compared to other methods. The purpose of this study is to investigate not only the reasons for the increase in exhaust temperature during intake or exhaust throttling but also their feasibility as a diesel particulate filter regeneration technology. In this study, a non-road diesel engine having a mechanical fuel injection pump was used for experiments. The changes in exhaust temperatures were measured during intake and exhaust throttling for the no-load maximum revolutions per minute engine condition. The experimental results exhibited that both intake and exhaust throttling reduced the intake air mass flow rate and increased piston pumping, which then increased fuel consumption. These effects were the primary reasons for increasing the temperature of exhaust gases. In particular, intake throttling was more effective than exhaust throttling in terms of reducing the intake air mass flow rate. However, exhaust throttling caused larger pumping losses, resulting in higher fuel consumption. Furthermore, in case of exhaust throttling, engine combustion was possible even at high equivalence ratios because of the larger amounts of residual gases in the combustion chamber. In summary, exhaust throttling is more effective for regenerating a diesel particulate filter at a high temperature than intake throttling. In addition, this study verified the feasibility of diesel particulate filter regeneration using exhaust throttling through analyses of diesel particulate filter regeneration efficiency, fuel consumption, and exhaust concentration when regenerating the diesel particulate filter by increasing the exhaust temperature through exhaust throttling.