Exhaust Gas Recirculation (EGR) has been in use for many years to control NOx emissions in commercial vehicle applications. Emissions limits are tighter with every new regulation while durability requirements continue to increase, so EGR system manufacturers must be able to provide high performance and robust designs even with high thermal loads.
The commercial vehicle market is characterized by lower production rates than passenger car programs and the same engine must cope with multiple applications that have totally different engine calibrations. In some cases it is necessary to design two or more EGR systems for an engine platform, with a consequential impact on cost and development timeline.
The optimal design of an EGR system needs to take into consideration several topics related with performance and durability: efficiency and pressure drop, fouling, boiling, thermal fatigue, vibration, pressure fatigue and corrosion among others. Furthermore, these designs must be cost effective and adaptable to different engine calibrations and duty cycles, which is a very complex process.
The presented work deals with technical solutions for solving the abovementioned issues based on the analysis of several engine specifications and duty cycles from different commercial vehicle engines. The same EGR design solution can be used across different applications and with only four EGR cooler designs it is possible to cover the full spectrum of engines from 2.2l up to 15l.