To reduce the NO x content in the exhaust gas, some of the exhaust gas is mixed with the fresh air in the intake stroke via the exhaust gas recirculation valve, depending on the load state.
In the Y 25 DT engine in the Omega-B the exhaust gases are conducted through a water cooling system upstream of the exhaust gas recirculation valve.
The recirculated exhaust gas is cooled down by approx. 100 °C.
This reduction in temperature prevents the fresh air from heating up too much which would reduce the filling capacity.
This achieves a constant, optimum cylinder filling capacity.
The exhaust gas recirculation valve is seated directly on the intake manifold in the intake air path.
The coolant flow through the radiator of the exhaust gas recirculation system is thermostatically controlled and is only enabled with high exhaust gas temperatures.
The exhaust gas is conducted through the exhaust gas recirculation system from the exhaust manifold (2) via the corrugated metal pipe (1) to the exhaust gas recirculation radiator.
The temperatures are equalised in the exhaust gas recirculation radiator (9) via the coolant in accordance with the heat exchanger principle.
The exhaust gas passes via another metal pipe (7) to the exhaust gas recirculation valve (6) which is located directly on the intake manifold (5) in the intake air path.
The coolant is conducted from the large coolant circuit via a thermostat to the connection (8) for the exhaust gas recirculation coolant feed.
The coolant returns into the coolant circuit via the exhaust gas recirculation coolant return (10).
| 1 | Exhaust gas recirculation corrugated pipe | 6 | Exhaust gas recirculation valve |
|---|---|---|---|
| 2 | Exhaust manifold | 7 | Exhaust gas recirculation metal pipe |
| 3 | Engine transport shackle | 8 | Connection for exhaust gas recirculation coolant feed |
| 4 | Cylinder head | 9 | Exhaust gas recirculation radiator |
| 5 | Intake manifold | 10 | Connection for exhaust gas recirculation coolant return |