Learning Forum

[ll00023]

I would like to calculate mixture fraction of coal combustion of a non-premixed burner.

the issue here is: I can only get volatile chemical reaction. as shown in figure below.

the formula of mixture fraction is for all the combustible substances in the coal. I didn't find any references about how to calculate mixture fraction for coal.

I just use the formulas here to estimate the stoichiometric mixture fraction (Zst) locations of volatile combustion. it coincides with the highest temperature and reaction rate.

is there any better way to estimate the Zst?

Thank you.

 

[Ren]

Hello,

From the coal ultimate analysis you can calculate the required O2 in kg for each kg of coal DAF, and then required air if air is the oxidizer. With the known stoichiometric air/fuel ratio (AFR), you can calculate the stoichiometric mixture fraction:

Zst = 1 / ( 1 + AFR)