Thermal analysis of a solar-assisted pyrolysis drop tube reactor with radiation heat transfer

Fast pyrolysis of biomass is recognized as a promising method for bio-oil production which can be further utilized in the production of sustainable fuels. Numerical simulations are carried out in order to verify the discrete ordinate method (DOM) implementation in OpenFOAM open-source software. 1D and 3D test problems are investigated including conjugate and radiative heat transfer in addition to a 2D test case. The main application of interest is a 3D solar-assisted drop tube reactor, which is studied from the viewpoint of heat distribution within the reactor. The main results of the research are as follows: (1) 1D modeling indicates that the heat fluxes are correctly implemented for transient and steady state configurations. (2) 2D rectangular enclosure study indicate correct heat flux implementation in OpenFOAM for the viewFactor and fvDOM methods. (3) 3D reactor studies in OpenFOAM and STAR-CCM+ indicate that the heat distributions are highly similar within 2% deviation in peak temperature values. The final 3D results are noted to be grid independent and independent on the angular discretization number when N ϕ ≥ 16 . As a conclusion, the validated/verified numerical approach offers a general open-source framework for coupled CHT-radiation problems with applicability beyond the studied drop tube reactor.