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

Abstract

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.

Thermal intermittent drying of apples and its effects on energy consumption

“…Thus, mass and energy balances were written in terms of the rate of dry air, which allows one to ignore the effect of air density due to the temperature and the relative humidity. [41] The environmental and heated air properties were determined by a psychrometric chart considering the altitude of São José do Rio Preto, Brazil (498 m).…”

Radial evolution of vascular elements in the oak Quercus ilex L. wood

“…Polge and Keller (1973), Klumpers (1994), Guilley (2000), Natterer et al (2004), andPerré et al (2012) showed that density decreases when the cambium is aging. R e f e r e n c e s Aussenac G. (1993) EW -vessel diameter in early wood, LW -vessel diameter in latewood, VD -vessel density, N -number of vessels, L -vessel length, INZ -internal zone, EXZ -external zone, SD -standard deviation, CV -coefficient of variation, S -significant difference, NS -non-significant difference…”

“…(i) For the importance of the vessel lumen and vessel number in the external zone and in the internal zone according to Hacke et al (2001), Meinzer (2003), Bucci et al (2004), andPerré et al (2012) suitable indicators are water storage capacity and conducting efficiency of water in the stem of Q. ilex. The surface of the lumen is 0.12 mm 2 in the internal zone, and 0.28 mm 2 in the external zone.…”

Multiscale Modeling for Food Drying: State of the Art

“…The majority of the multiscale models for drying has been conducted on timber. A series of works has been published for the various length scales for timber (Perré, Rémond, & Turner, ; Perré, Rémond, Colin, Mougel, & Almeida, ). Readers are directed to Perré () for a breakdown of the homogenization and an in‐depth description of the transport which occurs in these studies.…”