Hello Joe,
in regard to the EGR lowering combustion temperature, IF I recall
some decades-old chemistry correctly, the reason has to do with
the air / fuel mix being exothermic, or heat-producing.
Normally the fuel mix has air (oxygen 20% by volume) enough to
`burn' more or less completely, and since the carb mix has been s
set to optimize power (heat) output with `normal' air, adding
oxygen-depleted exhaust into the mixture has the effect of lowering
the heat output, since there is less free O2 available to react in
relation to a mix using 100% outside air.
Since gases don't have enough mass to hold much in the way of
latent heat, the fact that hot exhaust gas is used is less impor-
tant than the drop in the efficiency of the exothermic reaction.
Hope this helps, and hope I'm correct !
Any `real' chemists, not synthetic ones, please correct as necessary.
Best regards,
Tom Tweed
GC-MS lab technician, Wright State U. Chem. dept.
SW Ohio
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