Emission reduction with advanced two-actuator EUI for heavy-duty diesel engines

An advanced electronic unit injector has been developed with two electronically-controlled valves which provide a very flexible choice of injection characteristics. Tests on a single-cylinder engine have demonstrated the potential of this advanced EUI system. Substantial increases in injection pressure can be electronically-programmed at individual engine speed/load conditions compared with a baseline EUI system to provide much faster rates of air/fuel mixing. Simulated emissions cycle results showed that an optimised two-actuator EUI with EGR gave 30% lower NOx, 60% lower soot particulate and 6% lower BSFC compared with a baseline EUI result. A high-pressure post injection has the potential to give further soot reduction.