Journal of the Korean Society for Geothermal and Hydrothermal Energy (한국지열·수열에너지학회논문집)

Korean Society for Geothermal and Hydrothermal Energy (한국지열·수열에너지학회)
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Thermal Diffusivity Measurement of Backfilling Materials for Horizontal Ground Heat Exchanger Using Dual-Probe Method

이중탐침법을 이용한 수평형 지중열교환기 뒤채움재의 열확산계수 측정

  • Sohn, Byong-Hu (Green Building Research Division, Korea Institute of Construction Technology) ;
  • Choi, Hang-Seok (School of Civil, Environmental and Architectural Engineering, Korea University)
  • 손병후 (한국건설기술연구원 그린빌딩연구실) ;
  • 최항석 (고려대학교 건축사회환경공학과)
  • Received : 2011.11.04
  • Accepted : 2011.11.24
  • Published : 2011.12.01
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Abstract

Storage and transfer heat in soils are governed by the soil thermal properties and these properties are therefore needed in many engineering applications, including horizontal ground heat exchanger for ground-coupled heat pumps. This paper presents the measured results of the thermal diffusivity of soils(silica, quartzite, limestone, sandstone, and masonry soils) used for the trench backfilling materials of the horizontal ground heat exchanger. To assess this thermal property, we (i) measure the soil thermal conductivities and volumetric heat capacities using dual-probe method and (ii) compare the estimates from the de Vries method of summing the heat capacities of the soil constituents. The results show that the thermal diffusivity tends to increase as dry soil begins to wet, but it approaches a constant value or even decreases as the soil continues to wet. Measurements made by using the dual-probe method agreed well with independent estimates obtained using the single-probe method.

Keywords

References

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