Comparative Study of Thermophysical Parameters of Different Types of Upholstery Wood and the Influence of Density on Combustion Parameters at Microscale

Abstract

The fire behaviour of five types of wood was studied on a microscale. Some thermophysical parameters such as thermal conductivity, effusivity and diffusivity were also evaluated. The microscale analysis is based on the analysis of several parameters such as the assessment of heat released rates (HRR), peak heat released rates (pHRR), total heat released (THR), enthalpy variation (Δh) and residue rates with the combustion microcalorimeter (PCFC). The PF2C device was used to measure the conductivity, effusivity and diffusivity of wood, while the PCFC for the microscale study of wood behaviour in combustive situations. In terms of thermal conductivity, wood conducts heat with difficulty, while the other types, namely frake, bete, tek and red wood, more easily conduct heat and therefore cannot be considered as thermal insulators. For results, in terms of measuring effusivity, white wood has the smallest value, which means that it exchanges less thermal energy with its environment. Red and tek woods exchange much more energy with the environment compared to other types of wood. We observe that tek wood has the highest diffusivity, which means that it is the wood that reacts as quickly as possible to the change in temperature. White and frake woods have the same value of thermal diffusivity as red and bete wood which have the lowest thermal diffusivities. The fire behaviour of these materials is a very little variable on the microscale and we can conclude that at this level there is no major difference for our different types of wood. Hence, there is no influence of density on the microscale. We can say that for the white and tek wood the complete combustion begins at 700°C. By this same method of analysis, we come to the conclusion that the frake, bete and red woods tend towards a complete combustion at 675°C. At 675°C the bete and frake woods have the best combustive yields, to a lesser extent than the red and tek woods. The bete wood has the highest activation energy and the white wood the lowest.