The variation of thermal conductivity of fibrous insulation materials under different levels of moisture content

2013 ◽  
Vol 43 ◽  
pp. 533-544 ◽  
Author(s):  
A. Abdou ◽  
I. Budaiwi
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Insulation Materials ◽  
Fibrous Insulation ◽  
Different Levels

scholarly journals Thermo-Insulation Properties Of Hemp-Based Products

2015 ◽  
Vol 52 (1) ◽  
pp. 38-51 ◽  
Author(s):  
V. Lekavicius ◽  
P. Shipkovs ◽  
S. Ivanovs ◽  
A. Rucins
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
New Products ◽  
Environmental Safety ◽  
Insulation Materials ◽  
Fibrous Insulation

Abstract As known, many multi-purpose plants can be used in different industries. This research is focused on the possibilities to utilize hemp as feedstock for thermal insulation products. The most advantageous features of hemp insulation are associated with health and environmental safety. The thermal conductivity of commercially available hemp insulation products is comparable with that of other fibrous insulation materials; however, it is possible to develop new products that could be more efficient in terms of cost and due to other important features.

scholarly journals Thermal Conductivity Characteristics of Thermal Insulation Materials Immersed in Water for Cold-Region Tunnels

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Youyun Li ◽  
Yongmei Sun ◽  
Yuan Zhuang ◽  
LiMin Duan ◽  
Ke Xie
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Water Sample ◽  
Pore Water ◽  
Thermal Insulation ◽  
Water Distribution ◽  
Ct Scanning ◽  
Insulation Material ◽  
Insulation Materials ◽  
The Relationship

This study investigates the distribution of pore water on the basis of the measured mass moisture content after soaking the tunnel insulation material. This study also analyzes the influence of the distribution of pore water on the thermal conductivity of the material on the basis of this mass moisture content. Scanning images of phenolic and polyurethane insulation boards are obtained by computer tomography (CT). The gray volume moisture content (Gv) is deduced based on the CT scanning images, to determine the distribution of pore water (Gv is the ratio of the volume of the water sample (represented by the gray value) to the volume of the saturated water sample (represented by the gray value) which is the gray volume moisture content of the sample). The correlation between gray volume moisture content and mass moisture content is determined by comparing different algorithms of gray volume moisture content and volume moisture content. The relationship between mass moisture content and thermal conductivity can be determined using a self-made quasi-steady-state tester, whereas the relationship between gray volume moisture content and thermal conductivity can be derived indirectly. Related experimental research can predict the thermal conductivity of thermal insulation materials by using a new perspective and shows the influence of pore water distribution on the thermal conductivity of materials.

Performance Test and Research of Ceramic Fiberboard

2014 ◽  
Vol 488-489 ◽  
pp. 36-39
Author(s):  
Ru Ji ◽  
Xi Dong Wang ◽  
Zuo Tai Zhang ◽  
Li Li Liu
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Bulk Density ◽  
Effective Thermal Conductivity ◽  
Performance Test ◽  
Influence Factors ◽  
Thermal Capacity ◽  
Ceramic Fiber ◽  
Insulation Materials ◽  
Coefficient Of Thermal Conductivity

Ceramic fiber has great refractory and insulating ability. The coefficient of thermal conductivity is a significant characteristic of the fiber insulation materials, and shows the material thermal capacity. This paper not only research basic properties of ceramic fiberboard, but also focus on the influence factors of the effective thermal conductivity which include bulk density, temperature and moisture content.

Evaluation of Thermal Properties of Fibre Insulation Materials for Inflatable Mini Cold Storage

2013 ◽  
Vol 803 ◽  
pp. 213-217 ◽  
Author(s):  
Yan Wu ◽  
Jiu Chun Han ◽  
Xi Hong Li ◽  
Zhi Li
Keyword(s):  
Thermal Conductivity ◽  
Cold Storage ◽  
Loss Rate ◽  
Radiation Heat Transfer ◽  
Far Infrared ◽  
Decomposition Temperature ◽  
Initial Decomposition Temperature ◽  
Insulation Materials ◽  
Fibrous Insulation ◽  
Heat Preservation

Fibre materials, as thermal insulation materials, will be an optimum choice for inflatable mini cold storage. The evaluation index such as infrared spectrum, thermal stability and thermal conductivity is closely related to the selection and application of fibrous insulation materials. The results showed that the transmittance of bamboo fibre tested by Fourier Transform Infrared Spectroscopy (FTIR) measurements was about 35.3% with an advantage to the heat preservation, and radiation heat transfer was analyzed in the area of far-infrared. The initial decomposition temperature of 1#, 2# and 3# measured by TGA curve was respectively 383.9°C, 372.5°Cand 315.4°C, and the total thermal weight loss rate of 1#, 2# and 3# was 64.59%, 90.16% and 80.47%. The thermal conductivity of 1# at 0°C was 0.035 W·m-1·K-1, lower than 2# and 3#, also lower in the temperature range from 0°C to 8°C, measured by hypothermia thermal instrument.

scholarly journals Influence of Temperature and Moisture Content on Thermal Performance of Green Roof Media

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2421
Author(s):  
Bohan Shao ◽  
Caterina Valeo ◽  
Phalguni Mukhopadhyaya ◽  
Jianxun He
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Green Roof ◽  
Green Roofs ◽  
Power Functions ◽  
Thick Substrate ◽  
Different Temperatures ◽  
Test Cells ◽  
Substrate Moisture ◽  
Phase Transition Zone

The influence of moisture content on substrate thermal conductivity at different temperatures was investigated for four different commercially available substrates for green roofs. In the unfrozen state, as moisture content increased, thermal conductivity increased linearly. In the phase transition zone between +5 and −10 °C, as temperature decreased, thermal conductivity increased sharply during the transition from water to ice. When the substrate was frozen, thermal conductivity varied exponentially with substrate moisture content prior to freezing. Power functions were found between thermal conductivity and temperature. Two equally sized, green roof test cells were constructed and tested to compare various roof configurations including a bare roof, varying media thickness for a green roof, and vegetation. The results show that compared with the bare roof, there is a 75% reduction in the interior temperature’s amplitude for the green roof with 150 mm thick substrate. When a sedum mat was added, there was a 20% reduction in the amplitude of the inner temperature as compared with the cell without a sedum mat.

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