Influences of mechanical damage and water saturation on the distributed thermal conductivity of granite

Geothermics ◽  
2020 ◽  
Vol 83 ◽  
pp. 101736 ◽  
Author(s):  
Zheng-Wei Li ◽  
Yan-Jun Zhang ◽  
Yan-Hua Gong ◽  
Guo-Qiang Zhu
Geothermics ◽  
2017 ◽  
Vol 66 ◽  
pp. 1-12 ◽  
Author(s):  
Katharina Albert ◽  
Marcellus Schulze ◽  
Claudia Franz ◽  
Roland Koenigsdorff ◽  
Kai Zosseder

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 914
Author(s):  
Aleksandra Łukawska ◽  
Grzegorz Ryżyński ◽  
Mateusz Żeruń

The article presents the methodology of conducting serial laboratory measurements of thermal conductivity of recompacted samples of cohesive and non-cohesive soils. The presented research procedure has been developed for the purpose of supplementing the Engineering–Geology Database and its part–Physical and Mechanical Properties of Soils and Rocks (abbr. BDGI-WFM) with a new component regarding thermal properties of soils. The data contained in BDGI-WFM are the basis for the development of maps and plans for the assessment of geothermal potential and support for the sustainable development of low enthalpy geothermal energy. Effective thermal conductivity of soils was studied at various levels of water saturation and various degrees of compaction. Cohesive soils were tested in initial moisture content and after drying to a constant mass. Non-cohesive soils were tested in initial moisture, fully saturated with water and after drying to a constant mass. Effective thermal conductivity of non-cohesive soils was determined on samples mechanically compacted to the literature values of bulk density. Basic physical parameters were determined for each of the samples. In total, 120 measurements of thermal conductivity were carried out, for the purposes of developing the guidelines which allowed statistical analysis of the results. The results were cross-checked with different measuring equipment and with the literature data.


2018 ◽  
Vol 37 (2) ◽  
pp. 691-720 ◽  
Author(s):  
Boning Tang ◽  
Chuanqing Zhu ◽  
Ming Xu ◽  
Tiange Chen ◽  
Shengbiao Hu

The optical scanning method was adopted to measure the thermal conductivities of 418 drill-core samples from 30 boreholes in Sichuan basin. All the measured thermal conductivities mainly range from 2.00 to 4.00 W/m K with a mean of 2.85 W/m K. For clastic rocks, the mean thermal conductivities of sandstone, mudstone, and shale are 3.06 ± 0.73, 2.57 ± 0.42, and 2.48 ± 0.33 W/m K, respectively; for carbonate rocks, the mean thermal conductivities of limestone and dolomite are 2.53 ± 0.44 and 3.55 ± 0.71 W/m K, respectively; for gypsum rocks, the mean thermal conductivity is 3.60 ± 0.64 W/m K. The thermal conductivities of sandstone and mudstone increase with burial depth and stratigraphic age, but this trend is not obvious for limestone and dolomite. Compared with other basins, the thermal conductivities of sandstone and mudstone in Sichuan basin are distinctly higher, while the thermal conductivities of limestone are close to Tarim basin. The content of mineral composition such as quartz is the principal factor that results in thermal conductivity of rocks differing from normal value. In situ thermal conductivity of sandstones was corrected with the consideration of water saturation. Finally, a thermal conductivity column of sedimentary formation of the Sichuan basin was given out, which can provide thermal conductivity references for the research of deep geothermal field and lithospheric thermal structure in the basin.


2013 ◽  
Vol 291-294 ◽  
pp. 145-151 ◽  
Author(s):  
Wan Sheng Yang ◽  
Huang Huan Guo ◽  
Zhang Yuan Wang ◽  
Xu Dong Zhao

This paper studied the thermal and physical properties of a new solar solid desiccant material, including the equivalent thermal conductivity under different moisture content conditions and penetrability under different simulated solar radiation. The results showed that the equivalent thermal conductivity of the material was related to the moisture content and water saturation. In unsaturated state, the equivalent thermal conductivity increased with the increase of the moisture content and presented a linear relation in certain range. When reached saturation, the equivalent thermal conductivity decreased with the increase of the moisture content. These figures could provide the basis for the determination of the thickness of the dehumidification bed and optimization of the design of the dehumidification system.


2019 ◽  
Vol 53 (3) ◽  
pp. 1039-1051
Author(s):  
Zheng-Wei Li ◽  
Xia-Ting Feng ◽  
Yan-Jun Zhang ◽  
Yan-Hua Gong ◽  
Guo-Qiang Zhu

2014 ◽  
Vol 982 ◽  
pp. 90-93 ◽  
Author(s):  
Monika Čáchová ◽  
Dana Koňáková ◽  
Eva Vejmelková ◽  
Martin Keppert ◽  
Kirill Polozhiy ◽  
...  

Although plaster belonged to the first structural materials, they are still getting further enhancements. Nowadays different companies are producing and selling plasters that differ either in their composition or purpose. This article is comparing plasters presented on the market in the Czech Republic. Those are lightweight, renovation and even most common lime-cement plasters. Among the studied characteristics were: basic physical properties (for comparison were measurement of two methods: vacuum water saturation and helium pycnometry); they water vapor transport parameters and heat transport parameters. Lightweight and renovation plasters had shown the biggest porosity, lowest thermal conductivity and the highest diffusion resistance factor.


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