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Old 06 December 2007, 05:30   #41
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...How does Exhaust Gas Recirculating assist with emissions? Anyone knowlegable care to explain..or have I got to try and research (Google can be your friend)?
I am certainly not more knowledgeable with regards engines - but from a chemistry perspective, if I recall correctly, the aim of EGR is to reduce NOx emissions. Here is, from vague recollection, the chemical thinking:
  • NOx's are formed at high temperatures, from mixtures containing nitrogen and oxygen (e.g. air!)
  • higher proportions of oxygen cause engines to run "hotter"
  • mixing exhaust gas with the incoming mixture reduces the amount of oxygen which makes it harder for NOx to form (as less "spare" oxygen) and runs cooler so less tendency to form anyway.
  • the CO2 and H2O in the exhaust also help with "removal" of heat from the combustion chamber - as they have relatively high heat capacities (compared to air).
Now this was from some "fuel chemistry" lectures some years ago - my recollection was this being applied to Petrol combustion cycles - but I assume it is similar thinking on diesels.

Does that help?
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Old 06 December 2007, 05:34   #42
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Ah... I edited a bit sharpish...Sorry!
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Old 06 December 2007, 06:03   #43
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…anyone want to poke holes in my explanation?…
Nope. I was going to say pretty much wot you said but I remembered you told me not to argue with the Codmeister.

Mollers, I'm impressed.
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Old 06 December 2007, 06:42   #44
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In no way is this going to make the thing run more effeciently.

wel shitt a brikk. de nobbur iz rite

ifn yew wont too fuk orf de ERG vallve i av de anser att de amayzin pryce ov 15kwids

jus stikk dis hily developt peece ov enjineerin inn de vakyewm pype from de ERG valve an orl yorr problums arr sulved incloodin inncontinense

gaRf
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Old 06 December 2007, 09:54   #45
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I can't believe just how stupid some people are being regarding my remarks on the intercooler. Could it be they will just argue with ANYTHING I say??? Pathetic.....

I have poked around inside many intercoolers - not just on Land Rovers. Leaking seals - worn piston rings etc etc??? Well techinically maybe so but it even happens on new cars. Remember an exhaust pipe exits to the open air - with an intercooler the stuff just pools inside it as it has nowhere to go.

As to being worse for the environment how can an engine running more efficiently be worse??? That's the argument with a catalyst. It's like shoving a sock up your exhuast. It may reduce certain emmissions but it increases other as you are using more fuel......
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Old 06 December 2007, 11:22   #46
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Originally Posted by codprawn View Post
I can't believe just how stupid some people are being regarding my remarks on the intercooler. Could it be they will just argue with ANYTHING I say??? Pathetic.....

I have poked around inside many intercoolers - not just on Land Rovers. Leaking seals - worn piston rings etc etc??? Well techinically maybe so but it even happens on new cars. Remember an exhaust pipe exits to the open air - with an intercooler the stuff just pools inside it as it has nowhere to go.

As to being worse for the environment how can an engine running more efficiently be worse??? That's the argument with a catalyst. It's like shoving a sock up your exhuast. It may reduce certain emmissions but it increases other as you are using more fuel......

........................Brilliant.
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