地下钻孔换热器能量转移的数值模拟外文文献.pdfVIP

Applied Thermal Engineering 132 (2018) 697–707 Contents lists available at ScienceDirect Applied Thermal Engineering journal homepage: www.elsevi /locate/apthermeng Research Paper Numerical modeling of energy transfer in underground borehole heat exchanger within unsaturated soil Mohammad Hossein Jahangir ⇑, Hamid Sarrafha, Alibakhsh Kasaeian ⇑ Department of Renewable Energies, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran h i g h l i g h t s Numerical analysis is performed on underground heat exchangers in unsaturated soil. The heat convection of surface water, water vapor, and dry air are considered. The approximate relation of average stored energy within the medium is presented. Radial distribution of temperature and moisture content in the medium are evaluated. Energy loss becomes independent of distance from pipes after a specific time period. a r t i c l e i n f o a b s t r a c t Article history: In the current study, the heat emission and heat extraction process is numerically studied for six u- Received 5 September 2017 shaped upright underground pipes during a 10 day period. The soil medium is considered to be unsatu- Revised 24 December 2017 rated, which is the common case in most of the practical scenarios. For this purpose, the convective flows Accepted 5 January 2018 of dry air, water vapour, and surface water are simultaneously accounted for and the energy transfer Available online 6 January 2018 amounts