Exhaust gas recirculation should be burnt!

[Mischa]

please explain to me how EGR keeps combustion temps down.

thanks

i would also like to know

[Greg Roles]

Guys, I'm just rehashing what VW say in the 125kw engine training manual I downloaded from Erwin. Here's the guff:

Task of EGR:

The objective is to reduce nitrogen oxide emissions. This happens because:

1. Less Oxygen is available for combustion due to the recirculated exhaust gas,
2. The combustion speed and therefore increase in temperature are reduced by the exhaust gas that is introduced.

Remember that, in the later diesels at least, the exhaust goes via a cooler first.

But yeah, I too struggle with the idea of going to the trouble of intercooling the charge air, only to add hot exhaust gas post intercooler!

[gldgti]

i think its a load of baloney TBH. you put in some exhaust gas to replace the nice oxygen rich charge air that you go to all the work of comrpessing and cooling - so you reduce the efficiency of the cycle as a whole, but your instantaneous nitrous emissions are decreased a bit - whoopy doo.

i cant get over the amount of nonsense that goes on with emission control.

just make the engine as high performing and efficient as possible, then REDUCE the capacity as much as you can!