An improved steady-state apparatus for measuring thermal conductivity of soils

作者：Alrtimi A; Rouainia M^*; Manning D A C

来源：International Journal of Heat and Mass Transfer, 2014, 72: 630-636.

DOI：10.1016/j.ijheatmasstransfer.2014.01.034

• Thermal conductivity
• Soils
• Thermal cell
• Heat flow
• Thermal jacket

The thermal conductivity of soil is among the most critical parameters required to design ground heat exchangers, which are widely used as a renewable technology for providing heating and cooling for buildings. This paper describes the development of new test apparatus that can be used for soil specimens obtained from routine site investigation as well as reconstituted specimens. The design of the apparatus is based on the application of Fourier's law where one directional uniform heat flux is generated through two identical specimens, producing a measurable temperature gradient that is used to calculate the thermal conductivity of the specimen. A new concept of minimizing the radial heat losses using a thermal jacket as a heat insulation barrier was examined. It was found that the no-radial heat losses condition can be achieved with thermal jacket temperature approximately equal to the average value of the ambient temperature and average specimen temperature. All parameters that can affect the measurements have been tested and the results showed a good performance with margin of error upto 5%. An application of the new test procedures involved conducting several experimental tests on undisturbed and reconstituted soil samples highlighted the simplicity of this apparatus in measuring thermal conductivity of soil under different conditions.

• 出版日期2014-5