The investigation of thermal insulation property of the pine needle waste
摘要
In this work, we propose a preparation of two block-type samples as insulation material from organic waste of the Pinus sylvestris tree, with two different orientations to the heat flow: random for dried milled pine needles (DMPN) and perpendicular for dried raw pine needles (DRPN). To examine the performances of the two-block-type samples, the temperature evolution comparison is carried out with a commercial sandwich panel (CSP) for the same outdoor temperatures. Based upon such research findings, the experimental study is investigated at room temperature ranging from 18 to 30 °C, the outdoor temperature measured between 18 and 22 °C and relative humidity at 40%. The hygroscopic parameter of the materials is calculated by weighing them before and after drying at a temperature of 105 °C for 24 h. The moisture content obtained is respectively 52.40% for natural pine needles and decreased significantly by 3.32% for DRPN and 2.24% for DMPN. The studied materials exhibit excellent thermal conductivities of 0.0228 for DRPN with an exciting density 28.57 kg m−3 comparing to CSP with a thermal conductivity of 0.022 W m−1 K and a density of 42 kg m−3, and 0.0238 W m−1 K for DMPN, with a density of 32.72 kg m−3. In the examined temperature range, it is observed that the DRPN is more adapted as insulation material than the DMPN, because of its low mean temperature gradient 0.42 °C mm−1, comparing to DMPN 0.78 °C mm−1. The experimental results provide a thermal reference for the selected insulation materials and commonly used CSP in Algeria.