[Kummi]

Hello Foamers,
In my case, the wet coal pyrolysis model should be developed [absence of air - no combustion] involving the influence of moisture drying.

~ The influence of moisture drying is captured based on the phenomenon of boiling, condensation and convection. So, once after the moisture dried (@T=100deg) --> the pyrolysis occurs simultaneously.

~ In OpenFOAM by default, the FireFOAM is well supported for solid pyrolysis modelling. With that in mind, I managed to built my solver for a modified version of pyrolysis based on FireFOAM.

~ FireFOAM also supports surface film modelling + PhaseChangeModel --> LiquidEvaporation - but, thats not really what I m looking ahead.

PS: Guess, the moisture drying is not a kind of VOF approachable technique (or) solid melting problem, although the flow (physics) phenomenon might look related [Correct me if I'm wrong here please.]

My QUERY is:
~ Pyrolysis and moisture drying are different phenomenon. However, to make it work both phenomenon simultaneously, how and what kind of approach will be appropriate in OpenFOAM?

Although I have gone through many cases related to this study, unfortunately I'm out of ideas as how to overcome the problem of MOISTURE DRYING by implementing altogether (coupling) with PYROLYSIS.

I would really appreciate if anyone could give me a hint where to look at or point me about the implementation in OpenFOAM.

Thank you ^^

[Kummi]

Any ideas? Moisture drying during pyrolysis under regionModel in Firefoam ?

[clapointe]

Have you seen this publication? https://www.sciencedirect.com/scienc...10218017304510. Something similar would likely be your best bet.

Caelan

[Kummi]

Hello Clapointe,
Thank you for your thoughts.
Yae something similar - and in the paper attached, the radiative heat transfer and soot treatment is coupled with pyrolysis calculations. There is no solid-liquid interfaction, no combustion in my case. However, gives some insight ideas. Thank you once again.

I'm gaining more knowledge and all about the implementation of "Moisture drying phenomenon within pyrolysis" --> as drying and pyrolysis occurs simultaenously in different regions of same particle (so both phenomenon cant be modelled separately). Simplified ASSUMPTIONS --> escaping H2O vapor and volatiles are asuumed to be in thermal equilibrium and the solid volume is assumed to be constant throughout drying and pyrolysis (no shrinkage of particle in 1D modelling).


I identified 3 core papers related to my post and my query:
(1)https://www.sciencedirect.com/scienc...78382014002896
(2)https://www.researchgate.net/publica...penFoam_solver
(3)https://www.sciencedirect.com/scienc...96890415003325
All these papers modelled drying phenomenon using Arrhenius-type expression. But in my case, the moisture boiling is calculated based on mass balance (flux) and heat balance (flux) with conditions at boiling plane as follows:

T= 100 ==> alpha [moisture content) =0]
Based on it, mass and heat balances are calculated at interface as,
Mass balance (r) = rho * alpha * (dx/dt) [kg/m2.s]
Heat balance (-K dT/dx) = (r) * latent heat [W/m2]

REF - Clear details here in this MANUSCRIPT ~ https://www.sciencedirect.com/scienc...16236183902259


I read more documents and overall the basic flow physics seems to be same. But I don't find any clue about the approachable technique in OpenFOAM (or) in any kind of documents.
Keep exploring to find a way. Hoping for the best !!!