Keywords and Phrases
Borehole Heat Exchanger; Geothermal Energy; Geothermal System; Ground Source Heat Pump; Groundwater; Lithology
"Construction of large scale ground coupled heat pump (GCHP) systems that operate with hundreds or even thousands of boreholes for the borehole heat exchangers (BHE) has increased in recent years with many coming on line in the past 10 years. Many large institutions are constructing these systems because of their ability to store energy in the subsurface for indoor cooling during the warm summer months and extract that energy for heating during the cool winter months.
Despite the increase in GCHP system systems constructed, there have been few long term studies on how these large systems interact with the subsurface. The thermal response test (TRT) is the industry standard for determining the thermal properties of the rock and soil. The TRT is limited in that it can only be used to determine the effective thermal conductivity over the whole length of a single borehole at the time that it is administered. The TRT cannot account for long-term changes in the aquifer saturation, changes in groundwater flow, or characterize different rock and soil units by effectiveness for heat storage.
This study established new methods and also the need for the characterization of the subsurface for the purpose of design and long-term monitoring for GCHP systems. These new methods show that characterizing the long-term changes in aquifer saturation and groundwater flow, and characterizing different rock and soil units are an important part of the design and planning process of these systems. A greater understanding of how large-scale GCHP systems interact with the subsurface will result in designs that perform more efficiently over a longer period of time and expensive modifications due to unforeseen changes in system performance will be reduced"--Abstract, page iv.
Elmore, A. Curt
Guggenberger, Joe D., II
Maerz, Norbert H.
Cawlfield, Jeffrey D.
Geosciences and Geological and Petroleum Engineering
Ph. D. in Geological Engineering
Missouri University of Science and Technology
Journal article titles appearing in thesis/dissertation
- The effect of seasonal groundwater saturation on the effectiveness of large scale borehole heat exchangers in a karstic aquifer
- The observed effects of changes in groundwater flow on a borehole heat exchanger of a large scale ground coupled heat pump system
- Characterizing lithological effects on large scale borehole heat exchangers during cyclic heating of the subsurface
xiv, 97 pages
© 2017 David Charles Smith, All rights reserved.
Dissertation - Open Access
Electronic OCLC #
Smith, David Charles, "Characterizing long-term groundwater conditions and lithology for the design of large-scale borehole heat exchangers" (2017). Doctoral Dissertations. 2631.