Effects of EGR with a Supplemental Manifold Water Injection to Control Exhaust Emissions from Heavy-Duty Diesel Powered Vehicles

Combined system with EGR and Manifold water injection was developed for trial to control exhaust NOx emissions from heavy-duty diesel powered vehicles and its effects were experimentally studied under not only steady-state but also actual driving conditions including transient.

From the experimental analyses under steady-state conditions, it was recognized that higher NOx reduction may be possible with this combined system compared with the use of each method alone under the same level of other pollutants.

Then, several control conditions of the system were chosen and their effects to exhaust emissions were investigated under actual driving conditions, and consequently, about 50% of NOx reduction was recognized without significant increase of other pollutants by the combination of EGR at light and medium load regions and limited water injection at heavy load regions where accelerator opening is 70% or over. Any control condition of EGR and water injection did not deeply affect fuel consumption.