Bartłomiej Hryniewicki
supervisor: Michał Bartyś
The wood drying process has been studied for many years and actually is quite well described. Unfortunately, exact phenomenological model of this process is not available due to the very complicated physics and chemical phenomena taking place by drying. The solution to the problem of the batch version of this process is to reduce the drying speed in order to avoid wood cracking. This is performed in accordance with the operator's experience. The beneficial is that such approach typically avoids wood cracking and bending. The output of performed research is a physical model that is ready to be used for simulating wood drying process in the three-dimensional space. Later on, it was extended with autotuning capabilities which allow automated adaptation of its parameters depending on actual wood condition. Finally, the model was extended by the functionality providing approximated distribution of the internal wood mechanical stresses. This allows to develop a process control strategy that considers both moisture content and internal stress of the wood. Together with the dynamic models of heating and air exchange inside the drying chamber, the new control strategy will be helpful by optimizing entire drying process. It is expected that developed control strategy will prevent wood losses caused by bending and splitting. This will not only give an opportunity to save energy but also guarantee the final quality of the dried wood but also reduce time of the process.