Gas Radiation

[PhilOos]

Hi,

I'm trying to find the gas emissivity of flue gas in a combustion chamber of a power station. I know that there are many text books that give three graphs to determine the effects of CO2 and H2O...but I prefer to go the long way i.e. spectral analysis for I find that the tolerance on the graphs is too low.
I am currently struggling Wideband-Model section. Not so much the theory, but the MATH!!
My question is: Has anyone performed some math manipulation for the overlapping parameters of the various gasses? Help will be greatly appreciated.

Thanx and take care


Philip Oosthuizen
Company info:
SteinMuller Engineering Services

http://www.steinmuller.co.za/

 

[davefitz]

I would recommend you use the "russian normative method" as proposed by A G Blockh in "heat transfer in steam boiler furnaces". The math is developed , and condensed to a simpler correlation ,that is easily correlated and adjusted with test data from other furnaces that are already burning the same coal

Flyash dispersion in the furnace, combined with slag reflectivity, is a complex problem- a so called participating medium. The main problem is that there is no reliable database of the compelx index of refraction for suspended flyash particles, as a function of size distribution, shape, mineral matter. To add more complexity, the ash distribution , size, shape etc is changing as the char combusts. For australian coals, and US low sulphur subbit coals, the high levels of dielectric dolomites Ca and Mg act as IR scatterers- very complicated.

also, check some 1990- 2000 papers by B+W Woodrow Fiveland - he has published 3d CFD papers that include his mathematical devolution of these ash properties. What I foudn interesting was the way he managed to conform the radiation transfer equation to a form amenable to the galerkin method.