Considering Groundwater Advection on the Design of Borehole Heat Exchanger—A Review of Analytical Solutions

Y. Guo, J. Komar, W.V. Liu, M. Sepehri, Y. Pourrahimian

In the proceedings of: GeoEdmonton 2018: 71st Canadian Geotechnical Conference; 13th joint with IAH-CNC

Session: Shallow Geothermal Energy Exchange

ABSTRACT: The borehole heat exchanger (BHE) is a crucial component of GeoExchange systems because the efficiency of the system relies primarily on the heat transfer between BHE and its surrounding ground. When groundwater advection exists, this heat transfer can be enhanced, providing a synergistic effect on the thermal performance of BHE. As a result, this synergistic effect can shorten the design length of BHE, thereby reducing the drilling and installation costs. Although the benefit of groundwater advection is evident, most current design software have not considered the effects of groundwater advection due to its complexity and insufficient research in this area. Until now, there are only a few analytical solutions that have addressed this issue. However, these solutions were developed under different assumptions and boundary conditions, and there is little research to summarize and compare them. In the present study, the objective is to conduct a review of the analytical solutions that have accounted for the effects of groundwater advection on BHE. Firstly, a description was performed for various analytical models that involved groundwater advection and for different application conditions of these models (i.e., assumptions and boundaries). Then customized MATLAB coding was deployed to analyze the mathematical solutions for these analytical models using the same input parameters from a GeoExchange project in Edmonton (AB, Canada). After that, the results were summarized to reveal the advantage and disadvantage of these analytical solutions. Based on that, recommendations have been made for further study that includes groundwater advection in the BHE design.

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Cite this article:
Y. Guo; J. Komar; W.V. Liu; M. Sepehri; Y. Pourrahimian (2018) Considering Groundwater Advection on the Design of Borehole Heat Exchanger—A Review of Analytical Solutions in GEO2018. Ottawa, Ontario: Canadian Geotechnical Society.

@article{geo2018Paper298,author = Y. Guo; J. Komar; W.V. Liu; M. Sepehri; Y. Pourrahimian,title = Considering Groundwater Advection on the Design of Borehole Heat Exchanger—A Review of Analytical Solutions,year = 2018}