Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

Heat treatment of wood at relatively high temperatures (in the range of 180–240°C) is an effective method to improve the dimensional stability and to increase the biological durability of wood. During the heat treatment process, the heat and mass transfer takes place between the solid and the drying medium, and the moisture evaporation occurs within the solid due to the capillarity action and diffusion. In this article, a coupling method is presented for high temperature heat treatment of wood based on ThermoWood technology. A three-dimensional mathematical model considering the simultaneous unsteady heat and moisture transfer between a gas phase and a solid phase during heat treatment has been developed. The conservation equations for the wood part are obtained using the diffusion equation with variable diffusion coefficients, and the 3-dimensional incompressible Reynolds-averaged NavierStokes equations have been solved for the flow field. The coupling between the two parts is achieved by expressing the continuity of the state variables and their respective fluxes through the interface. A detailed discussion of the computational model and the solution algorithm is given.