Specific Heat Capacity of Wood

Kristijan Radmanović,Igor Đukić,Stjepan Pervan

doi:10.5552/drind.2014.1333

Abstract

Specific heat capacity is defined as the amount of heat that a kilogram of a given substance is required to absorb in order to increase its temperature by one degree. The temperature of a given substance can change either at constant pressure or at constant volume, so we differentiate between specific heat capacity at constant pressure (cp) and specific heat capacity at constant volume (cv). When doing research into the heat properties of wood, the quantity that most frequently remains constant is pressure, thus restricting our study on specific heat capacity to cp. This paper provides an overview of the research that has so far been carried out into the specific heat capacity of wood depending on the temperature and moisture content. An analytical and graphical comparison has been performed of the results published in the Wood Industry Manual (1967) (DIP), Wood Handbook (1999) (WH) and work published by Deliiski (2012) (DEL).

Highlights

This paper provides an overview of the research that has so far been carried out into the specific heat capacity of wood depending on the temperature and moisture content
This data leads to the conclusion that the specific heat capacity of wood depends on the temperature and moisture content, while the variations between different wood species were very small
Due to the difference in results obtained by many authors, a comparison was drawn between the theoretical research conducted by Deliiski (2012) (DEL) and the research mentioned in the Wood Handbook (1999) (WH) and the Wood Technology Handbook (1967) (DIP)

Summary

INTRODUCTION

The thermal properties of wood are essential physical properties, especially in the processes of drying, producing heat energy by combustion and other processes, which include the transfer of heat through wood. The thermal properties of wood are as follows: specific heat capacity (c), coefficient of thermal conductivity (k) and thermal diffusivity (α). These three properties of wood are interconnected by the expression:. Pw p0 pfw pbw where: cpw - specific heat capacity of wood, J/kg·°C, cp0 - specific heat capacity of wood of dry wood substance, J/kg·°C, cpfw - specific heat capacity of free water, J/kg·°C, cpbw - specific heat capacity of bound water, J/kg·°C. The specific heat capacity of free and bound water depends on the state of matter. Free water in wood changes its state of matter in a temperature range of -2 °C to -0.1 °C, depending on the concentration of dissolved sugar in water (Kubler et al, 1964; Chudinov, 1968), whereas bound water undergoes only a partial phase change in a wide temperature range at temperatures lower than -2 °C

SPECIFIČNI TOPLINSKI KAPACITET SUHE DRVNE TVARI

RASPRAVA

Findings

ZAKLJUČAK

LITERATURA