Exhaust System - Mercedes-Benz OM 651 Service Manual

Exhaust system

Exhaust gas recirculation
The exhaust system of engine 651 combines two tech-
nologies for emission reduction. Exhaust gas recircu-
lation (EGR) reduces emissions of nitrogen oxide (NO
and exhaust treatment reduces the emission of hydro-
carbons (HC) and soot particles.
With exhaust gas recirculation, part of the exhaust
flow is guided back through the EGR path to the
charge air.
Exhaust gas recirculation
1 EGR pre-cooler
2 EGR cooler
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Introduction of New Generation of 4-Cylinder Inline Engines, OM 651
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– This printout will not be recorded by the update service. Status: 09 / 2008 –
The recirculated exhaust gas enters the EGR path via
a pre-cooler. There it is either cooled according to its
) temperature or fed directly to the charge air. The
x
exhaust-air mixture enters the combustion chamber
directly via the charge air manifold.
Exhaust gas recirculation reduces the oxygen (O
concentration and combustion temperature.
3 Charge air manifold
4 Exhaust manifold
)
2