Exhaust Gas Recirculation
As already used in the X 12 SZ / X 16 SZ engine, a linear exhaust gas recirculation valve is used to decrease nitrogen oxide emissions. In principle, exhaust gas has an inert composition, i.e. it is not combustible. This exhaust gas is returned to the combustion chamber (external exhaust gas recirculation).
Nitrogen oxide formation increases dramatically as the combustion temperature increases. Exhaust gas recirculation is therefore a very effective method for lowering the temperature (decreasing peak combustion temperatures) and reducing nitrogen oxides.
The linear exhaust gas recirculation system consists of the following components
1 Exhaust gas recirculation solenoid valve (actuator)
2 Exhaust gas recirculation solenoid valve position sensor (response to control unit)
3 Control unit
An exhaust gas recirculation module for amplifying the signal between the control unit and the exhaust gas recirculation valve, as used in the X 12 SZ / X 16 SZ engines, is not required for the X 14 XE / X 16 XE engines.