Korean Journal of Air-Conditioning and Refrigeration Engineering (설비공학논문집)

The Society of Air-Conditioning and Refrigerating Engineers of Korea (대한설비공학회)
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Predicting the Effective Thermal Conductivity of Some Sand-Water Mixtures Used for Backfilling Materials of Ground Heat Exchanger

지중열교환기 뒤채움재로 사용되는 모래-물 혼합물의 열전도도 예측

  • Sohn, Byong-Hu (Fire and Engineering Services Research Center, KICT)
  • 손병후 (한국건설기술연구원 화재 및 설비연구센터)
  • Published : 2008.09.10
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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

References

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