Variation of Bulk and Particle Thermal Properties of Some Selected Wood Materials for Solar Device Applications

Abstract

The study examines the variation of thermal properties of bulk and particle of three different wood species: Pterygota macrocarpa, Milicia excelsa and Celtis philippensis of the families of Sterculiaceae, Moraceae and Ulmaceae. The particle samples were moulded to appropriate disc shape using modified hydraulic press mould while the bulk samples were turn into disc shape using circular saw machine. The results showed that thermal conductivity of the selected wood materials changed with particle sizes. Bulk samples have higher thermal conductivity values than the particles for all the wood species. Among the particle sizes, 300 μm has the highest thermal conductivity value compared with 600 μm and 850 μm respectively. It was established in the research that the thermal conductivity of wood materials in the study ranged between 0.0855 -0.3150 Wm -1 K -1 for particle sizes and 0.2130-0.4298Wm -1 K -1 for bulk samples. The wood samples for the specific particle sizes exhibit low thermal conductivity that is comparable with materials used as industrial insulators. Within the limit of this research, all the particle sizes considered potent better thermal insulators compared with bulk wood materials.