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Analysis of Soil Thermal Conductivities, Borehole Thermal Resistances and Initial Soil Temperature with In-Situ Testing in South Korea

현지 측정에 의한 남한지역의 지중유효열전도도, 보어홀 전열저항 및 초기온도 분석

  • Ro, Jeong-Geun (School of Mechanical Eng., Chungbuk National University) ;
  • Yon, Kwangseok (Dept. of Biosystem Eng., Chungbuk National University) ;
  • Song, Heon (School of Architecture, Kwandong University)
  • 노정근 (충북대학교 기계공학부) ;
  • 연광석 (충북대학교 바이오시스템공학과) ;
  • 송헌 (관동대학교 건축학부)
  • Received : 2012.07.31
  • Accepted : 2012.10.23
  • Published : 2012.10.30

Abstract

Investigation of the effective soil thermal conductivity($k$) is the first step in designing the ground loop heat exchanger(borehole) of a geothermal heat pump system. Another important factor is the borehole thermal resistance($R_b$). Thermal response tests offer a good method to determine the ground thermal properties for the total heat transport in the ground. The first step is measured for initial soil temperature. This is done by supplying a only pump power into a borehole heat exchanger. They need to supply into water unload heat power more than 30 minutes. In this study, the initial soil temperature was found to analysis $14.1{\sim}16.0^{\circ}C$,the ratio was 68.7% represented. In this case of $k$, was 2.1~3.0 $W/m{\cdot}k$, $R_b$ was 0.11~0.20 $m{\cdot}K/W$. In this work, it is also shown that the distribution of a soil thermal conductivity and borehole thermal resistance were on the influence of initial soil temperature. And soil thermal conductivity was related with factors of equation by linear least square method, borehole thermal resistance was on the influence of composite factors.

Keywords

References

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