Specific heat capacity of thermally modified wood at different levels of temperature and moisture content

Document Type : Research Paper

Author

Associate prof., Department of wood and paper science & technology, Faculty of natural resources, University of Tehran, Karaj, Iran

Abstract

The amount of specific heat capacity is important for processes that require heat transfer in wood, as well as for design of wood structures that undergo high temperature changes during day. In this research, specific heat capacity of thermally modified oak were measured in comparison with unmodified wood in the temperature range of -20 to 20 °C under dry and wet conditions using differential scanning calorimetry (DSC). Results showed that there was no significant difference between the specific heat capacities of two types of wood at dry condition, and the average values were 1.47 J.g-1K-1 at 20 °C and 0.84 J.g-1K-1 at -20 °C. In contrast, the specific heat capacity of the modified wood at -20 °C under wet condition was greater than that of unmodified wood, and more heat flux was used to melt the ice. In contrast to a linear relationship between the dry specific heat capacity and temperature in the range of 0 to 20 °C, the relationship was nonlinear for temperatures below 0 °C.

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References

[1] Thybring, E.E., 2014.  Explaining the heat capacity of wood constituents by molecular vibrations. Journal of Material Science, 49: 1317-1327. 
[2] Czajkowski, L., Olek, W., Weres, J., Guzenda, R., 2016. Thermal properties of wood-based panels: specific heat determination. Wood Science Technology, 50:537–545.
[3] Dunlop, F., 1912. The specific heat of wood. U.S. Dep. Agr., Forest Serv. Bull. 110.      
[4] Kollman, F.F.P., Cote, W.A., 1968. Principles of Wood Science and Technology, Springer-Verlag, Berlin, Germany.
[5] Koch, P., 1969: Specific Heat of Ovendry Spruce Pine Wood and Bark. Wood Science, 1(4): 203-214.
[6] Kanter, K. R., 1957. The thermal properties of wood. Nauka i Tekhnika, 6(7):17-18.
[7] Kuhlman, G., 1962. Investigation of the thermal properties of wood and particleboard in dependency from moisture content and temperature in the hygroscopic range. Holz als Roh-und Werkstoff, 20(7): 259-270.
[8] Steinhagen, H.P., 1977. Thermal conductive properties of wood, green or dry, from-40 °C to 100 °C—a literature review. General technical report FPL-9, USDA Forest Service, Madison.
[9] Gupta, M., Yang, J. and  Roy, C., 2003. Specific heat and thermal conductivity of softwood bark and softwood char particles. Fuel, 82: 919–927.
[10] Radmanović, K., Dukić, I. and Pervan, S., 2014. Specific Heat Capacity of Wood. Drvna Industrija 65 (2): 151-157.
[11] Aggrey-Smith, S., Preko, K. and Owusu, F.W., 2016. Study of Thermal Properties of Some Selected Tropical Hard Wood Species. International Journal of Materials Science and Applications, 5(3): 143-150.
[12] Li, K.Y., Fleischmann, C.M. and Spearpoint, M.J., 2013. Determining thermal physical properties of pyrolyzing New Zealand medium density fibreboard (MDF). Chemical Engineering Science, 95:211–220.
[13] Standard Test Method for Determining Specific Heat Capacity by Differential Scanning Calorimetry, Annual Book of ASTM Standard, E 1269-11, 2018.
 [14] Deliiski, N., Tumbarkova, N., Stanev, R. and Dzurenda, L., 2015. Computation of the wood temperature conductivity above the hygroscopic range during wood freezing, Annals of Warsaw University of Life Sciences – SGGW, Forestry and Wood Technology, 91: 40-45.
Iranian Journal of Wood and Paper Industries
Volume 10, Issue 2
August 2019
Pages 163-173

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