COMPARISON OF THE 1D AND 3D MODELS FOR THE SIMULATION OF WOOD HEAT TREATMENT PROCESS

Wood heat treatment at high temperatures (in the range of 180–240°C) is an ecological alternative to the chemical treatment of wood for its preservation. Thermal treatment provides dimensional stability and biological durability to wood due its structural changes. The dark color attained also gives the wood an aesthetic appearance. Various mathematical models have been developed for wood heat-treatment furnaces. In this article, two models, 1D and 3D, will be described. They have been used to simulate the furnace behaviour for a number of wood species, and parametric studies have been carried out to determine the impact of various factors. Some of the results of the calculations with the two models will be presented. They will be compared and the applicability and limitations of the 1D approach will be discussed. NOMENCLATURE Symbols: C concentration (kg m -3 ) Cp heat capacity (J kg -1 K -1 ) D diffusion coefficient of water vapor in the fluid (m 2 s -1 ) DS diffusion coefficient in the wood material (m 2 s -1