Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Evaluation on Thermal Performance of Thermosyphon by Numerical Analysis

열사이펀의 열성능 산정을 위한 수치해석 연구

  • Jang, Changkyu (Univ. of Science and Technology) ;
  • Choi, Changho (Geotechnical Engineering Research Division, SOC Research Institute, Korea Institute of Civil Engineering and Building Technology) ;
  • Lee, Jangguen (Geotechnical Engineering Research Division, SOC Research Institute, Korea Institute of Civil Engineering and Building Technology) ;
  • Lee, Chulho (Geotechnical Engineering Research Division, SOC Research Institute, Korea Institute of Civil Engineering and Building Technology)
  • 장창규 (과학기술연합대학원대학교) ;
  • 최창호 (한국건설기술연구원 SOC성능연구소 Geo-인프라연구실) ;
  • 이장근 (한국건설기술연구원 SOC성능연구소 Geo-인프라연구실) ;
  • 이철호 (한국건설기술연구원 SOC성능연구소 Geo-인프라연구실)
  • Received : 2014.08.19
  • Accepted : 2014.10.01
  • Published : 2014.09.30
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Abstract

The ground in cold region consists of active and permafrost layers. The active layer at the unstable state may cause ground corrosion and uplift, when the temperature of frozen ground increases due to seasonal changes. The thermosyphon is one of the stabilization methods to maintain the ground stability in the frozen ground. The thermosyphon is a closed two-phase convection device that extracts heat from the ground and discharges it into the atmosphere. In this study, ground freezing experiment using a thermosyphon and simulated ground with the isolation material was conducted to evaluate the thermal performance of the thermosyphon. In order to consider the thermal performance of the thermosyphon, commercial numerical program (TEMP/W) was adopted. Likewise, the thermal performance of thermosyphon and thermal properties of ground were applied in the numerical model. In a series of comparisons with experiment results and numerical study, thermal performance of thermosyphon can be evaluated.

동토지역에서는 계절변화에 상관없이 항시 영하상태로 동결되어 있는 영구동토층과, 그 위로 동결융해가 반복되는 활동층으로 구성되어있다. 일반적으로 대기온도 변화에 따라 동결융해가 반복되는 활동층은 얼음과 물의 상변화 작용이 반복되기 때문에 지반의 융기현상과 침하현상, 그리고 영구동토층의 온도상승을 초래할 수 있다. 열사이펀이란 구조체 내부에 충전된 냉매의 자가적인 열순환을 이용하여 지반의 온도를 영하상태로 제어하는 지반 안정화 공법 중 하나이다. 열사이펀은 대기중에 냉매의 열을 방출하는 응축부와 지중에 열을 흡수하는 증발부로 구성되어 있으며 대기의 온도가 영하의 상태일 때 지반의 온도를 영하상태로 제어한다. 본 연구에서는 열사이펀의 지반 열전달성능을 분석하기 위해 모형지반에 단열재를 배치하여 열사이펀을 통한 지반동결실험을 수행하였다. 단열재의 열차단성 및 열사이펀 길이를 고려하여 단열재 및 열사이펀의 성능실험을 수행하였으며, 실험에서 얻어진 물성치를 상용수치해석 프로그램인 TEMP/W에 반영하였다. 본 연구에서 제시된 실내실험과 수치해석 방법을 통해 열사이펀의 열성능을 산정할 수 있었다.

Keywords

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