Testing Study on Moisture Content Effect on Thermal Conductivity for Clay

2015 ◽  
Vol 730 ◽  
pp. 97-100
Author(s):  
Yan Duan ◽  
Hua Jin ◽  
Xu Zhao Wang
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Influence Factors ◽  
Correlation Equation ◽  
Second Phase ◽  
Key Factors ◽  
Exchange Performance ◽  
Positive Linear Correlation ◽  
Ground Coupled Heat Pump ◽  
Thermal Conductivity Probe

Thermal conductivity is one of the key factors influence the heat exchange performance of Ground-coupled heat pump systems (GCHP), which is effected significantly by soil moisture content around the ground heat exchanger system. The clay thermal conductivity under moisture content of 0, 5%, 10%, 15%, 20%, 25% and 30% were determined through thermal conductivity probe experiment. The results showed a variation with three phases of the thermal conductivity changes with clay moisture content, that firstly, the thermal conductivity increased slowly with a moisture content of 0~5%, secondly, which sharply increased with a high positive linear correlation when the moisture content was 5%~25%, then the growth tendency was slow even began to fall, as well as the correlation equation of the second phase was fitted. This study provides methodological and theoretical references for the further research on the influence factors of thermal conductivity under various situations.

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.

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.

Measuring the Thermo-Technical Parameters of Autoclaved Aerated Concrete

2016 ◽  
Vol 824 ◽  
pp. 100-107 ◽  
Author(s):  
Alena Struhárová
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Physical Properties ◽  
Bulk Density ◽  
Capillary Absorption ◽  
Measuring Device ◽  
Technical Parameters ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete ◽  
Technical Properties

Bulk density and moisture content are factors that significantly affect the physical properties of autoclaved aerated concrete (AAC) including thermal conductivity and other thermo-technical characteristics. This article shows the results of measurements of compressive strength, capillary absorption, water absorption and porosity of AAC (ash on fluidized fly ash) at different bulk density and also the results of thermal conductivity of AAC at different bulk density and variable moisture content of the material. The thermo-technical properties were measured using the Isomet 2104, a portable measuring device. Acquired results demonstrate dependence of physical properties including thermal conductivity of AAC on bulk density and moisture content. The reliability and accuracy of the method of measuring was also shown.

Testing Study on the Influence Factors to the Straw Pellet Fuel Broken Strength

2013 ◽  
Vol 448-453 ◽  
pp. 786-790
Author(s):  
Wei Gao ◽  
Rong Fei Zhao ◽  
Qing Yu Liu ◽  
Xu Wei Bai
Keyword(s):  
Moisture Content ◽  
Optimal Parameter ◽  
Influence Factors ◽  
Raw Material ◽  
Single Factor ◽  
Quadratic Regression ◽  
Corn Straw ◽  
Fermentation Time ◽  
Optimization Parameter ◽  
Single Factor Experiment

This paper take link mold pellet pelletizer to carry on the pellet fuel manufacture experiment with corn straw stalk. The influence of moisture content, material size and fermentation time impact on broken strength is studied by single factor experiment. Through quadratic regression orthogonal rotating combination experiment, establish mathematics equation of the factors and the straw pellet fuel broken strength and analyze the important degree of each experimental factor impact on the granulation rate. Through the optimized computation, definite optimization parameter of the highest broken strength is that raw material moisture content is 20%, fermentation time is 4h and particle size is 2.5mm. The result of verifying experiment indicat that the optimal parameter combination and the predict data measured were consistent.

The influence of moisture content on the thermal conductivity of external thermal mortars

2017 ◽  
Vol 135 ◽  
pp. 279-286 ◽  
Author(s):  
M. Glória Gomes ◽  
I. Flores-Colen ◽  
L.M. Manga ◽  
A. Soares ◽  
J. de Brito
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content

scholarly journals Estimation of thermal conductivity of short pastry biscuit at different baking stages

2014 ◽  
Vol 45 (2) ◽  
pp. 64 ◽  
Author(s):  
Chiara Cevoli ◽  
Angelo Fabbri ◽  
Simone Virginio Marai ◽  
Enrico Ferrari ◽  
Adriano Guarnieri
Keyword(s):  
Thermal Conductivity ◽  
Thermal Processing ◽  
Physical Property ◽  
Physical Models ◽  
Hot Wire ◽  
Line Heat Source ◽  
Food Material ◽  
Wire Method ◽  
Thermal Conductivity Probe

Thermal conductivity of a food material is an essential physical property in mathematical modelling and computer simulation of thermal processing. Effective thermal conductivity of non-homogeneous materials, such as food matrices, can be determined experimentally or mathematically. The aim of the following research was to compare the thermal conductivity of short pastry biscuits, at different baking stages (60-160 min), measured by a line heat source thermal conductivity probe and estimated through the use of thermo-physical models. The measures were carried out on whole biscuits and on powdered biscuits compressed into cylindrical cases. Thermal conductivity of the compacted material, at different baking times (and, consequently at different moisture content), was then used to feed parallel, series, Krischer and Maxwell-Eucken models. The results showed that the application of the hot wire method for the determination of thermal conductivity is not fully feasible if applied directly to whole materials due to mechanical changes applied to the structure and the high presence of fats. The method works best if applied to the biscuit component phases separately. The best model is the Krischer one for its adaptability. In this case the value of biscuit thermal conductivity, for high baking time, varies from 0.15 to 0.19 Wm<sup>–1</sup> K<sup>–1</sup>, while the minimum, for low baking time, varies from 0.11 to 0.12 Wm<sup>–1</sup> K<sup>–1</sup>. These values are close to that reported in literature for similar products.

scholarly journals Effect of Ultrasonic Treatment on Radon Exhalation from Porous Media: An Experimental Case Study

2018 ◽  
Vol 10 (9) ◽  
pp. 3005
Author(s):  
Ling-feng Xie ◽  
Shu-liang Zou ◽  
Xiang-yang Li ◽  
Chang-shou Hong ◽  
Hong Wang ◽  
...  
Keyword(s):  
Porous Media ◽  
Moisture Content ◽  
Ultrasonic Wave ◽  
Linear Correlation ◽  
Experimental Results ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Radon Exhalation ◽  
Experimental Apparatus ◽  
Positive Linear Correlation

Radon is internationally recognized as one of the seven seismic precursors. A self-assembly ultrasonic generator and experimental apparatus for radon measurement were utilized to explore the radon exhalation regularities of water-bearing porous media under different ultrasonic intensities. The experimental results showed that there was a coupling relationship among radon exhalation rate, moisture content, and ultrasonic frequency. With the increase of the frequency of the ultrasonic wave, its effect on the promotion of radon exhalation rate was found to be a more obviously positive linear correlation. The radon exhalation rate, which could climb to a maximum value of 0.179 Bq·m−2·s−1 in a naturally air-dried sample, increased at first and then decreased along with increased moisture content. Moreover, this study found that the ultrasonic wave had the most remarkable promoting effects on the radon exhalation rate of porous media with high moisture content, and there is a positive linear correlation between the growth rate of the radon exhalation rate and moisture content. The experimental results could provide a beneficial reference for the continual monitoring of radon in a seismically active belt and an explanation of radon anomalies; however, the proposed experimental model was simplified, so further insights are strictly required for a reliable correlation with the real monitoring of radon in a seismically active belt.

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