The effects of electrostatic precipitator in EGR system on the combustion and exhaust gas of marine diesel engines

Exhaust gas recirculation (EGR) is an effective way of reducing NOx, especially in the exhaust gas from automotive engines that has low particulate concentration, by suppressing the peak combustion temperature. Unlike automotive engines, exhaust gas from marine diesel engines that use low-grade fuel with high concentrations of sulphur and abrasive particles cannot be supplied to engine for EGR, unless the particulate is reduced. The author's previous research indicates that an electrostatic precipitator (ESP) can successfully reduce marine diesel particulate matter Hence, in this research, a combined EGR and ESP system capable of simultaneously reducing NOx and particulate matter (PM) was developed. The exhaust gas that was treated by ESP was supplied to the air intake manifold under various conditions, and the results show that a combined EGR/ESP system reduces NO and PM concentrations in exhaust gas. The combination system also improves the rate of heat release.