Modeling and automatic control of heat energy consumption required for thermal treatment of logs

A summarized 2-dimensional mathematical model has been developed, solved, and verified for the transient non-linear heat conduction and energy consumption in frozen and non-frozen logs at arbitrary, initial and boundary conditions met in practice. For the first time the model takes into account the fiber saturation point of each wood species and the specific heat capacity of wood as well as its ice content, formed by freezing of free and hygroscopically bounded water. This paper presents solutions of the model and the simulative investigation of the impact of the processing medium temperature and the initial wood temperature (in presence and absence of ice in the wood) on the change of heat energy required by wood for reaching different temperatures in the centre of logs. The results are used for the development of the algorithm and system for optimizing automatic control of the process of thermal treatment of logs in veneer production.