EGR ratio from exhaust gas composition

AI Thread Summary
The discussion centers on calculating the EGR (Exhaust Gas Recirculation) ratio from exhaust gas composition, specifically under the assumption of stoichiometric combustion producing only CO2, H2O, and N2. It is concluded that molar ratios of exhaust gases do not depend on the EGR ratio, and even with excess air, EGR cannot be determined using the same logic. A reference to an SAE paper suggests a potential connection between EGR and gas concentrations in exhaust, which contradicts the earlier conclusions. Attempts to apply the findings from the paper resulted in different outcomes, reinforcing the belief that mole fractions in exhaust gases are independent of the recycle ratio. The discussion highlights the complexity of accurately determining EGR from exhaust gas composition.
mrcarbon4hydrohen

Homework Statement


given:-fuel and air mass flow, measured mole ratios of exhaust composition y_i. Let's assume stoichiometric combustion so we have only CO2, H20 and N2 as products.

Homework Equations


Can EGR ratio be calculated from available data?

The Attempt at a Solution


skica zadatka (2).jpg

I get result that molar ratios don't depend on EGR ratio.
 
  • Like
Likes berkeman
Physics news on Phys.org
Your first equation already tells you this.
 
I have another question. I there is excess air, can EGR be determined? Folowing the same logic as before, it can't. This time I used a slightly different formula but result is the same.
slika_1.png


slika_2.png
but..
I found a SAE paper in which (Fresh Air+EGR)/Fuel ratio is determined by exhaust concentrations. So I think there is connection between EGR and gas concentations in exhaust. This is the paper(you can see in preview of SAE paper what I am reffering to, equation (3)): http://papers.sae.org/2010-01-1285/ .I tried to get solution as in paper, but got different result.
slika_3.png
 

Attachments

  • slika_1.png
    slika_1.png
    2.9 KB · Views: 618
  • slika_2.png
    slika_2.png
    2.3 KB · Views: 652
  • slika_3.png
    slika_3.png
    6.7 KB · Views: 630
As best I can tell, the mole fractions of the gases in the exhaust are independent of the recycle ratio.
 

Thread 'Prove that evolution is constant (Provide at least two arguments to support your position)'

I don't get how to argue it. i can prove: evolution is the ability to adapt, whether it's progression or regression from some point of view, so if evolution is not constant then animal generations couldn`t stay alive for a big amount of time because when climate is changing this generations die. but they dont. so evolution is constant. but its not an argument, right? how to fing arguments when i only prove it.. analytically, i guess it called that (this is indirectly related to biology, im...
View full post »

Similar threads

Stoichiometry-calculation of mass fraction of water in exhaust
Replies
1
Views
4K
Volumetric flow rate ratio calculation
Replies
1
Views
3K
Automotive Loss of gaseous volume because of fuel combustion
Replies
2
Views
1K
Chemistry Ideal Gas Law and Partial Pressures
Replies
16
Views
3K
As much steam as possible from engine exhaust gas + warm water?
Replies
25
Views
4K
Analyzing Oxygen Ratios in Magnesium Oxide Lab Reactions
Replies
10
Views
17K
Composition of fuel, AFR , & of air
Replies
3
Views
3K
Properties of Thiazole: Balancing Reactions, Yields & Mass Ratios
Replies
16
Views
4K
Automotive Removal of EGR system: performance gain or loss?
Replies
11
Views
165K
What Exhaust Pipe Diameter is Needed for a Given Exhaust Speed?
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top