University of Quebec at Chicoutimi, Department of Applied Sciences, 555, Boul. de l'Université, Chicoutimi, Quebec, Canada.
Bioresour Technol. 2010 Jun;101(12):4630-8. doi: 10.1016/j.biortech.2010.01.089. Epub 2010 Feb 18.
The present study is devoted to a numerical study with experimental validation of the high-temperature thermal treatment of three-dimensional wood pole. 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. The development of the model equations, taking into account both bulk phases and interfaces of the multiphase system is described, starting from the microscopic scale. Fundamental to this model is the ability to quantify the effects of key material and geometric properties of the pole. The three-dimensional and unsteady-state mathematical model equations are solved numerically by the commercial package FEMLAB for the temperature and moisture content histories under different treatment conditions. A detailed discussion of the computational model and the solution algorithm is given. Heat treatment was applied on the test samples in an oven for three final temperatures (180, 200 and 220 degrees C). A series of experimental tests aimed at determination of heat treatment schedules kinetics curves and the temperature and moisture profiles and there time evolution were carried out. A very good agreement between the experimental and predicted results was obtained, implying that the proposed numerical algorithm can be used as a useful tool in designing high-temperature wood pole treatment processes.
本研究致力于对三维木杆进行高温热处理的数值研究和实验验证。在热处理过程中，固体和干燥介质之间发生热质传递，由于毛细作用和扩散，固体内部发生水分蒸发。从微观尺度出发，描述了考虑多相系统的体相和界面的模型方程的发展。该模型的基础是能够量化木杆的关键材料和几何特性的影响。通过商业软件 FEMLAB 对三维非稳态数学模型方程进行数值求解，得到了不同处理条件下的温度和含湿量历史。详细讨论了计算模型和解算算法。将试件在烘箱中加热至三个最终温度（180、200 和 220°C）进行热处理。进行了一系列旨在确定热处理时间表动力学曲线以及温度和湿度分布及其时间演变的实验测试。实验结果与预测结果吻合较好，表明所提出的数值算法可作为设计高温木杆处理过程的有用工具。
