Modeling of Radiative Heat Transfer in 2D Complex Furnace of Biomass Pyrolysis Fumes: A Study of Shadow Effect

2009 ◽  
Author(s):  
Mohamed Ammar Abbassi ◽  
Kamel Guedri ◽  
Mohamed Naceur Borjini ◽  
Kamel Halouani ◽  
Belkacem Zeghmati
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Complex Geometry ◽  
Transfer Problem ◽  
Finite Thickness ◽  
Biomass Pyrolysis ◽  
Maximum Heat ◽  
Shadow Effect ◽  
Heat Recuperator

The radiative heat transfer problem is investigated numerically for 2D complex pilot plant of biomass pyrolysis composed by two pyrolysis chambers and a heat recuperator. In order to increase gases residence time and heat transfer, the heat recuperator is provided with many inclined, vertical, horizontal, diffuse and gray baffles of finite thickness and has a complex geometry. The Finite Volume Method (FVM) is applied to study radiative heat transfer. The blocked-off region procedure is used to treat the geometrical irregularities. Seven cases are considered in order to demonstrate the effect of adding baffles on the walls of the heat recuperator and on the walls of the pyrolysis rooms then choose the best case giving the maximum heat flux transferred to the biomass in the pyrolysis chambers. Shadow effect caused by the presence of the baffles is also studied.

Analysis of Combined Conductive-Radiative Heat Transfer in a Two-Dimensional Rectangular Enclosure With a Gray Medium

1988 ◽  
Vol 110 (2) ◽  
pp. 468-474 ◽  
Author(s):  
W. W. Yuen ◽  
E. E. Takara
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Diffusion Approximation ◽  
Radiative Heat ◽  
Transfer Problem ◽  
Numerical Procedure ◽  
Numerical Data ◽  
Two Dimensional ◽  
One Dimensional ◽  
Benchmark Solutions

Combined conductive–radiative heat transfer in a two-dimensional enclosure is considered. The numerical procedure is based on a combination of two previous techniques that have been demonstrated to be successful for a two-dimensional pure radiation problem and a one-dimensional combined conductive–radiative heat transfer problem, respectively. Both temperature profile and heat transfer distributions are generated efficiently and accurately. Numerical data are presented to serve as benchmark solutions for two-dimensional combined conductive–radiative heat transfer. The accuracy of two commonly used approximation procedures for multidimensional combined conductive–radiative heat transfer is assessed. The additive solution, which is effective in generating approximation to one-dimensional combined conductive–radiative heat transfer, appears to be an acceptable empirical approach in estimating heat transfer in the present two-dimensional problem. The diffusion approximation, on the other hand, is shown to be generally inaccurate. For all optical thicknesses and conduction-radiation parameters considered (including the optically thick limit), the diffusion approximation is shown to yield significant errors in both the temperature and heat flux predictions.

scholarly journals CONVERGENCE OF THE FINITE VOLUME METHOD FOR A CONDUCTIVE-RADIATIVE HEAT TRANSFER PROBLEM

2013 ◽  
Vol 18 (2) ◽  
pp. 274-288 ◽  
Author(s):  
Karlis Birgelis ◽  
Uldis Raitums
Keyword(s):  
Heat Transfer ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Transfer Problem ◽  
Uniform Boundedness ◽  
Mesh Size ◽  
Heat Transfer Problem ◽  
Volume Method

We show that the finite volume method rigorously converges to the solution of a conductive-radiative heat transfer problem with nonlocal and nonlinear boundary conditions. To get this result, we start by proving existence of solutions for a finite volume discretization of the original problem. Then, by obtaining uniform boundedness of discrete solutions and their discrete gradients with respect to mesh size, we finally get L 2type convergence of discrete solutions.

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