COUPLED MULTI-SOLVER METHODOLOGY AND APPLICATION TO A LARGE SCALE INDUSTRIAL FURNACE
Résumé
In most large scale industrial furnaces transient heat treatments involving all modes of heat transfer occur over long periods of time. In such installations, radiation is tightly coupled with conduction and convection. Transient Computational Fluid Dynamics (CFD), extended to solve radiation and solid conduction, requires considerable computing resources and long CPU time to simulate such systems. This paper deals with the transient multi-physical multi-mesh simulation of large scale industrial thermal systems. The Component Interaction Network (CIN), which belongs to the dynamic thermal simulation methods, is used to finely resolve the 3D coupled transient conduction and radiation problem. Steady-state CFD is used to solve the air flow details including turbulence and buoyancy effects. The two modelling approaches are linked via a newly proposed coupling method that allows the incorporation of the fluid flow effects in the thermal model by field averaging. The proposed methodology takes advantage of the speed of CIN for conduction and radiation simulation while minimizing assumptions on the flow field using a certain number of CFD solutions. A large scale industrial aluminium brazing furnace during its 2 hours cool down cycle is simulated using the proposed coupling methodology and the results are experimentally validated. While classical CFD-type multi-physical transient simulation of such large scale installations over long periods of time (3 hours) is unthinkable, the proposed methodology allows the determination of the 3D transient temperature field inside the furnace for the whole cool down cycle in just under 30 hours on a regular work-station.