Energy Consumption in the Convective Drying of Timber Analyzed by a Multiscale Computational Model

Energy consumption during timber drying has become an increasingly important issue, alongside conventional concerns such as quality, cost, and drying time. This paper proposes a detailed analysis of the energy consumption evolution in conventional kiln drying using a sophisticated modelling approach. The formulation of energy consumption proposed by Perré et al.[ 1 ] was embedded in a multiscale computational model to consider kiln drying of a stack of boards. The drying of each board in the stack is simulated using a full version of a heat and mass transfer code (the 1-D version of TransPore), which allows all boards to be different and facilitates consideration of wood variability, in addition to the effect of position within the stack. For simple configurations, the energy consumption predicted by this complex computational tool is in agreement with the global approach.[ 1 ] Moreover, this sophisticated model is able to account for the standard deviation of the final moisture content (MC), which allows a compromise to be struck between quality, drying time, and energy consumption. In addition, this model can also be applied to test innovative, energy-saving drying strategies with an equivalent drying quality, i.e. sorting boards of similar properties before drying, or sorting boards at the end of drying to re-dry those boards that have a final MC that is still too high.

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