Browse > Article

Predicting the Effective Thermal Conductivity of Some Sand-Water Mixtures Used for Backfilling Materials of Ground Heat Exchanger  

Sohn, Byong-Hu (Fire and Engineering Services Research Center, KICT)
Publication Information
Korean Journal of Air-Conditioning and Refrigeration Engineering / v.20, no.9, 2008 , pp. 614-623 More about this Journal
Abstract
This paper presents the results of a laboratory study on the thermal conductivity of and(silica, quartzite, limestone, sandstone, granite and two masonry sands)-water mixtures used for ground heat exchanger backfilling materials. Nearly 260 tests were performed in a thermal conductivity measuring system to characterize the relationships between the thermal conductivity of mixtures and the water content. The experimental results show hat the thermal conductivity of mixtures increases with increasing dry density and with increasing water content. The most widely used empirical prediction models for thermal conductivity of soils were found inappropriate to estimate the thermal conductivity of unsaturated sand-water mixtures. An improved model using an exponential relationship to compute the thermal conductivity of dry sands and empirical relationship to assess the normalized thermal conductivity of unsaturated sand-water mixtures is presented.
Keywords
Thermal conductivity; Sand-water mixture; Ground heat exchanger; Backfilling material; Transient hot probe method;
Citations & Related Records
Times Cited By KSCI : 5  (Citation Analysis)
연도 인용수 순위
1 Kline, S. J., 1985, The purpose of uncertainty analysis, J. Fluids Engineering, Vol. 107, pp. 153-160   DOI
2 IGSHPA, 2000, Grouting for Vertical Geothermal Heat Pump Systems : Engineering Design and Field Procedures Manual, International Ground Source Heat Pump Association, Stillwater, Oklahoma
3 Kersten, M. S., 1949, Laboratory research for the determination of the thermal properties of soils, Research Laboratory Investigations, Engineering Experiment Station, Technical Report 23, University of Minnesota, Minneapolis, MN, USA
4 Carslaw, H. S. and Jaeger, J. C., 1947, Conduction of Heat in Solids, 2nd ed., Oxford University Press
5 Sohn, B. H., 2007, Evaluation of ground effective thermal conductivity and borehole effective thermal resistance from simple linesource method, Korean Journal of Air-Conditioning and Refrigeration Engineering, Vol. 19, No. 7, pp. 512-520   과학기술학회마을
6 KSA, 2006, KS F 2324 : 2006 Method of classification of soils for engineering purposes, Korean Standards Association
7 Sohn, B. H. and Shin, H. J., 2006, Thermal conductivity measurement of grouting materials for ground heat exchanger borehole, Korean Journal of Air-Conditioning and Refrigeration Engineering, Vol. 18, No. 6, pp. 493-500   과학기술학회마을
8 Sohn, B. H., 2008, Thermal conductivity measurement of sand-water mixtures used for backfilling materials of vertical boreholes or horizontal trenches, Korean Journal of Air-Conditioning and Refrigeration Engineering, Vol. 20, No. 5, pp. 342-350   과학기술학회마을
9 Yari, M. and Javani, N., 2007, Performance assessment of a horizontal-coil geothermal heat pump, Int. J. Energy Research, Vol. 31, pp. 288-299   DOI   ScienceOn
10 KSA, 2006, KS F 2308 : 2006 Test method for density of soil particles, Korean Standards Association
11 Smith, W. O., 1942, The thermal conductivity of dry soils, Soil Science, Vol. 53, pp. 425-459
12 Sohn, B. H., Shin, H. J. and Park, S. K., 2005, Evaluation of effective thermal conductivity and thermal resistance in ground heat exchanger boreholes, Korean Journal of Air-Conditioning and Refrigeration Engineering, Vol. 17, No. 8, pp. 695-703   과학기술학회마을
13 KSA, 2000, KS F 2306 : 2000 Test method for water content of soils, Korean Standards Association
14 Leong, W. H., Tarnawaski, V. R. and Aittomaki, A., 1998, Effect of soil type and moisture content on ground heat pump performance, Int. J. Refrigeration, Vol. 21, No. 8, pp. 595-606   DOI   ScienceOn
15 Farouki, O. T., 1982, Evaluation of methods for calculating soil thermal conductivity, CRREL Report 82-8, US Army Corps of Engineers, Cold Regions Research and Engineering Laboratory, Hanover, NH, USA
16 Kavanaugh, S. P. and Allan, M. A., 1999, Testing of thermally enhanced cement ground heat exchanger grouts, ASHRAE Transactions, Vol. 105, pp. 446-450
17 Zhang, Q. and Murphy, W. E., 2000, Measurement of thermal conductivity for three borehole fill materials used for GSHP, ASHRAE Transactions, Vol. 106, pp. 434-441
18 Johansen, O., 1975, Thermal Conductivity of Soils, Ph. D. thesis, University of Trondheim, Trondheim, Norway. (CRREL Draft English Translation 637, US Army Corps of Engineers, Cold Regions Research and Engineering Laboratory, Hanover, NH, USA)
19 Rohsenow, W. M., 1973, Handbook of Heat Transfer, McGraw-Hill, New York
20 Lee, S. K., Woo, J. S., Ro, J. D. and Kim, D. K., 2006, A study on the estimation of soil formation thermal conductivities and borehole resistances with one-dimensional numerical model and in-situ field tests, Korean Journal of Air-Conditioning and Refrigeration Engineering, Vol. 18, No. 10, pp. 783-790   과학기술학회마을
21 KSA, 2002, KS F 2302 : 2002 Test method for particle size distribution of soils, Korean Standards Association