Using cellular automata to simulate external heat and mass transfer in the wood drying process

Abstract

This work involves modeling the external heat and mass transfer in the wood drying chamber. One of the remarkable features of this research is to use cellular automata with variable cell sizes closely related to the geometric parameters of the considered wood materials. This approach allows for modeling and analyzing the changes in the characteristics of wood materials during the hydrothermal treatment process, taking into account their unique geometry. Such modeling provides valuable information about how different shapes and sizes of wood react to various drying conditions. This research has significant implications for industries dependent on wood drying, such as construction and furniture production, as it offers an individual approach to upgrading the drying processes of wood materials with different geometries. The modeling in this work is carried out using wood materials, primarily pine, with a standardized thickness of 25 mm and an initial moisture content of 30 %. The modeling is conducted under conditions of moderate drying, accurately mirroring real-world scenarios. Using pine as the researched material aimed to represent a widely used wood species in the industry, thereby increasing the relevance of the results. The work also explores the influence of various parameters of the wood drying agent. To achieve this, three key factors are systematically varied: temperature, relative humidity, and drying agent velocity. Temperature fluctuations are carried out within a range of ±10 °C. Similarly, relative humidity is adjusted within ±10 % of standard technological parameters. Finally, the drying agent velocity was increased to a maximum of 6 m/s. Thus, the impact of these changes on the moisture content in wood materials is investigated. The results obtained can be applied in an industrial setting. The knowledge gained from the experiments can play a crucial role in improving the wood drying process. In summary, the work investigates the hydrothermal treatment of wood materials, shedding light on the critical role of wood drying agent parameters in controlling moisture content in wood materials. The potential advantages in terms of product quality and overall production efficiency cannot be overstated, and it is expected that this work will be a valuable resource for industries dependent on wood processing.

Software tools for calculating the main parameters of the drying process of anisotropic materials

“…In previous works [4,5], a cellular automaton model was developed and studied to determine the change in moisture content in lumber during drying. The transition rules developed in these works used constant values of the initial moisture content of lumber, for example, U 0 = 0.35, which were assigned to all cells without exception.…”

“…In real drying chambers, the control of drying agent parameters is carried out on the basis of existing automated systems with parallelization of the output values of parameters to a computer communication device, which makes it possible to determine the values of moisture transfers coefficients based on the current state of the drying agent parameters. In this case, the earlier developed [4,5] cellular automaton model will be used, which makes it possible to determine the main parameters of the drying agent, which include relative humidity and temperature. One of the conditions for the adequacy of the calculated parameters of the states with the real ones is the condition that lumber with identical physical and mechanical characteristics must be placed in the drying chamber.…”