Thermal radiation and conduction properties of materials ranging from sand to rock-fill

This paper presents an experimental study on thermal radiation and the thermal conductivity of rock-fill materials using a 1 m × 1 m × 1 m heat transfer cell. Testing temperatures are applied by temperature-controlled fluid circulation at the top and bottom of the sample. Heat flux and temperature profiles are measured to establish the effective thermal conductivity λe, which includes contributions from both conduction and radiation heat transfer mechanisms. The materials studied had an equivalent particle size (d10) ranging from 90 to 100 mm and porosity (n) ranging from 0.37 to 0.41. The experimental results showed that thermal radiation greatly affects the effective thermal conductivity of materials with λe values ranging from 0.71 to 1.02 W·m−1·K−1, compared with a typical value of 0.36 W·m−1·K−1 for conduction alone. As expected, the effective thermal conductivity increased with particle size. An effective thermal conductivity model has been proposed, and predictions have been successfully compared w...

[1]  N. Wakao,et al.  EFFECTIVE THERMAL CONDUCTIVITY OF PACKED BEDS , 1969 .

[2]  J. Konrad,et al.  Estimating Hydraulic and Thermal Conductivities of Crushed Granite Using Porosity and Equivalent Particle Size , 2011 .

[3]  W. Woodside,et al.  Thermal Conductivity of Porous Media. I. Unconsolidated Sands , 1961 .

[4]  M. J. Laubitz.  THERMAL CONDUCTIVITY OF POWDERS , 1959 .

[5]  D. Kunii,et al.  Heat transfer characteristics of porous rocks , 1960 .

[6]  M. Kaviany.  Principles of heat transfer in porous media , 1991 .

[7]  R. Viskanta,et al.  An Experimental Evaluation of the Effective Thermal Conductivities of Packed Beds at High Temperatures , 1994 .

[8]  G. Vasseur,et al.  Mineralogy, porosity and fluid control on thermal conductivity of sedimentary rocks , 1989 .

[9]  James G. Berryman,et al.  Thermal conductivity of porous media , 2004 .

[10]  O. Johansen.  Thermal Conductivity of Soils , 1977 .

[11]  D. Goering.  Convective Cooling in Open Rock Embankments , 2002 .

[12]  J. Meseguer,et al.  Thermal radiation heat transfer , 2012 .

[13]  Ismail H. Tavman,et al.  Effective thermal conductivity of granular porous materials , 1996 .

[14]  William Schotte,et al.  Thermal conductivity of packed beds , 1960 .

[15]  Radiative heat transfer in preforms for microstructured optical fibres , 2007 .

[16]  L. Yuanming,et al.  Evaluation of fractured rock layer heights in ballast railway embankment based on cooling effect of natural convection in cold regions , 2005 .

[17]  Jangguen Lee,et al.  Loading Effects on Thermal Conductivity of Soils: Particle-Scale Study , 2011 .

[18]  E. Ratcliffe.  The thermal conductivities of ocean sediments , 1960 .

[19]  Gilbert F. Froment,et al.  Heat transfer in packed beds , 1972 .

[20]  J. Konrad,et al.  Assessment of structure effects on the thermal conductivity of two-phase porous geomaterials , 2009 .

[21]  J. Salisbury,et al.  Midinfrared spectral features of rocks and their powders , 2002 .

[22]  Li Dongqing,et al.  In Situ Test on Cooling Effectiveness of Air Convection Embankment with Crushed Rock Slope Protection in Permafrost Regions , 2005 .

[23]  J. Konrad,et al.  Thermal conductivity of base-course materials , 2005 .

[24]  C. Tien.  Thermal Radiation in Packed and Fluidized Beds , 1988 .

[25]  T. Matsunaga.  Emissivity spectra derived from TIMS data acquired over a partially vegetated area , 1993, Proceedings of IGARSS '93 - IEEE International Geoscience and Remote Sensing Symposium.

[26]  J. Konrad,et al.  A generalized thermal conductivity model for soils and construction materials , 2005 .

[27]  J. Konrad,et al.  Natural convection of compressible and incompressible gases in undeformable porous media under cold climate conditions , 2009 .

[28]  C. L. Tien,et al.  Thermal radiation in particulate media with dependent and independent scattering , 1987 .

[29]  W. O. Smith.  THE THERMAL CONDUCTIVITY OF DRY SOIL , 1942 .

[30]  D. Goering.  EXPERIMENTAL INVESTIGATION OF AIR CONVECTION EMBANKMENTS FOR PERMAFROST-RESISTANT ROADWAY DESIGN , 1998 .

[31]  Stuart W. Churchill,et al.  Radiant heat transfer in packed beds , 1963 .

[32]  H. Godbee,et al.  Thermal Conductivities of MgO, Al2O3, and ZrO2 Powders to 850°C. II. Theoretical , 1966 .

[33]  H. Fricke,et al.  A Mathematical Treatment of the Electric Conductivity and Capacity of Disperse Systems I. The Electric Conductivity of a Suspension of Homogeneous Spheroids , 1924 .

[34]  Douglas J. Goering,et al.  Passively Cooled Railway Embankments for Use in Permafrost Areas , 2003 .

[35]  D. Goering.  Air Convection Embankments for Roadway Construction in Permafrost Zones , 1996 .

[36]  D. Goering,et al.  Winter-time convection in open-graded embankments , 1996 .

[37]  Y. Lai,et al.  Laboratory investigation on cooling effect of coarse rock layer and fine rock layer in permafrost regions , 2004 .

[38]  CôtéJean,et al.  Intrinsic permeability of materials ranging from sand to rock-fill using natural air convection tests , 2011 .