Coal Devolatilisation

James Macphee

Firstly thankyou to anyone that responds to my question. Your help is greatly appreciated.

My question relates to the two competing rates devolatilisation model. I am modelling pulverised coal fired through an swirling burner into a furnace. I have information on the proximate and ultimate analysis and high temperature volatile yield of the coal.

I am using the two mixture fraction/PDF approach and defining the volatiles as the emperical secondary stream. When I set values for the mass fraction of each element should I take into consideration the high temperature yield or just use the values from the ultimate analysis. From what I understand my coal flame does not necessarily achieve the high temp yield but is probably more than the proximate analysis yield that is found under slow(???) heating conditions. Also should I keep the second weighting factor as 1 or set it to the high temp yield fraction that I know.

Thanks again for any help. I am stuck as to where to go with this.