Skip to Main Content
Book Chapter

Petrographic and hydrogeologic investigations for a district-scale ground-coupled heat pump—Ball State University, Indiana

By
Andrew Siliski
Andrew Siliski
Department of Geological Sciences, Ball State University, 2000 W. University Avenue, Muncie, Indiana 47306, USA
Search for other works by this author on:
Lee J. Florea
Lee J. Florea
Department of Geological Sciences, Ball State University, 2000 W. University Avenue, Muncie, Indiana 47306, USA
Search for other works by this author on:
Carolyn B. Dowling
Carolyn B. Dowling
Department of Geological Sciences, Ball State University, 2000 W. University Avenue, Muncie, Indiana 47306, USA
Search for other works by this author on:
Klaus Neumann
Klaus Neumann
Department of Geological Sciences, Ball State University, 2000 W. University Avenue, Muncie, Indiana 47306, USA
Search for other works by this author on:
Alan Samuelson
Alan Samuelson
Department of Geological Sciences, Ball State University, 2000 W. University Avenue, Muncie, Indiana 47306, USA
Search for other works by this author on:
Marsha Dunn
Marsha Dunn
Department of Geological Sciences, Ball State University, 2000 W. University Avenue, Muncie, Indiana 47306, USA
Search for other works by this author on:
Published:
March 01, 2016

Thermal response tests are the industry standard for borehole heat exchanger design in ground-coupled heat pump systems. Two previously conducted thermal response tests in phase 2 of the district-scale ground-coupled heat pump system at Ball State University (BSU) measured a bulk “formation” thermal conductivity K T between 2.6 and 3.0 W m−1 K−1. Meanwhile, K T from a core recovered near BSU averages 2.2 ± 0.006 and 3.5 ± 0.086 W m−1 K−1 for dry and water-saturated samples, respectively. The range in K T data from saturated samples (1.8–7.2 W m−1 K−1) leads to the conclusion that thermal response tests do not capture the vertical and horizontal heterogeneity of heat flux in layered sedimentary aquifers.

Characterization of the hydrogeologic environment can be one tool to tune district-scale ground-coupled heat pump systems to the specific on-site conditions that may influence the magnitude and mode of heat transfer. At BSU, temperature (T) changes in the groundwater environment at the active phase 1 field through October 2013 support this notion. After constant heat loading, a T increase of 14–18 °C was observed in the central monitoring well. The vertical structure in the T profile of this well may correlate to “thermofacies.” For example, a T spike between 14 and 19.5 m in depth may correspond to a sand and gravel zone in the surficial glacial till, and a T dip at a depth of 70 m agrees with the position of the Brainard Shale—zones of higher permeability and lower measured K T (2.0 W m−1 K−1), respectively. Higher measured K T zones, such as the low siliciclastic Silurian Salamonie Limestone and the Ordovician Whitewater Formation, may be target thermofacies for heat deposition and extraction. In contrast, sand and gravel zones within the glacial till may allow for significant thermal loading; however, groundwater advection may reduce the fraction of recoverable thermal load.

You do not currently have access to this article.

Figures & Tables

Contents

GSA Special Papers

Geothermal Energy: An Important Resource

Gordon R. Osinski
Gordon R. Osinski
Centre for Planetary Science and Exploration, Departments of Earth Sciences and Physics and Astronomy, University of Western Ontario, 1151 Richmond St., London, ON N6A 3K7, Canada
Search for other works by this author on:
David A. Kring
David A. Kring
Center for Lunar Science and Exploration, Lunar and Planetary Institute, 3600 Bay Area Boulevard, Houston, Texas 77058, USA, and National Aeronautics and Space Administration (NASA) Lunar Science Institute, and NASA Solar System Exploration Research Virtual Institute
Search for other works by this author on:
Geological Society of America
Volume
519
ISBN print:
9780813725192
Publication date:
March 01, 2016

References

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal