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http://dx.doi.org/10.7843/kgs.2013.29.8.65

Development of Thermal-Hydro Pipe Element for Ground Heat Exchange System  

Shin, Ho-Sung (Dept. of Civil & Environmental Engrg., Univ. of Ulsan)
Lee, Seung-Rae (Dept. of Civil & Environmental Engrg., KAIST)
Publication Information
Journal of the Korean Geotechnical Society / v.29, no.8, 2013 , pp. 65-73 More about this Journal
Abstract
Ground-coupled heat pump system has attracted attention as a promising renewable energy technology due to its improving energy efficiency and eco-friendly mechanism for space cooling and heating. Pipes buried in the ground play a role of direct thermal interaction between circulating fluid inside the pipe and surrounding soils in the geothermal exchange system. However, both complexities of turbulent flow coupling thermal-hydraulic phenomena and very long aspect ratio of the pipe make it difficult to model the heat exchange system directly. Energy balance for fluid flow inside the pipe was derived to model thermal-hydraulic phenomena, and one-dimensional pipe element was proposed through Galerkin formation and time integration of the equation. Developed element is combined to pre-developed FEM code for THM phenomena in porous media. Numerical results of Thermal Response Test showed that line-source model overestimates equivalent thermal conductivity of surrounding soils due to thermal interaction between adjacent pipes and finite length of the pipe. Thus, inverse analysis for the TRT simulation was conducted to present optimal transformation matrix with utmost convergence.
Keywords
Ground heat exchange system; Thermal-Hydro pipe element; FEM; Thermal response test;
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Times Cited By KSCI : 4  (Citation Analysis)
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