Solar drying of timber in Harbin, China

The variation in seasonal conditions causes an impact on the wood-water relations and dimensional stability like shrinkage and swelling with solar drying technology, leading to discrepancies in drying qualities. To address this processing problem, we studied the pattern of drying kinetics and dimensional changes in four seasons and Northeast China. The experimental analysis shows that the Page, the Aghbashlo et al., the two-term exponential, and the Weibull models may be applied to emulate solar drying kinetics during different seasons of poplar timber. The results also show that the diffusion coefficients fall below the range of 6.01 x 10-11 to 1.52 x 10-9 m2/s, the activation energy mean is 32.74 kJ mol-1, and the R2 is 0.84 and the wood dimensional changes during the drying are in descending order of summer, spring, winter, and fall. Conclusively, solar timber drying is seasonally affected, and related studies are needed to provide a theoretical basis to develop the numerical modeling, and a thermo-mass-mechanical multi-physics coupled model for the seasonality of solar drying. This research will eventually provide references for improving the application of solar drying technology in different regions of the world, such as the development of heat storage media in different seasons, the upgrade of drying equipment, and the standardization of solar intermittent drying schedules.

Automated summary

Variations in seasonal conditions impact the wood-water relations and dimensional stability during solar drying. Different models can be used to simulate drying kinetics during different seasons. Wood dimensional changes are most significant in summer and least in fall. Further research is needed to provide a theoretical basis and develop models to address the seasonality of solar drying.