Development trends for heavy engines
- Magazine Feature Article
Compliance to today's emission legislations for heavy-duty (HD) diesel engines in commercial vehicles (CVs) demands a reduction of NOx and particulate matter emissions in the entire engine operating range including high load points. A very effective way to reduce the raw NOx emissions at high loads is to operate the engine with high exhaust gas recirculation (EGR) rates. At the same time, the air fuel ratio (AFR) must be kept constant to a level needed to hold the particulate emissions under the allowed limit. An increase of fuel injection pressure also aids in lowering of particulate emissions.
Meeting these and future emissions legislation requirements while maintaining or even increasing the specific torque and power output of the engine presents challenging requirements to the base engine design, according to experts at