The Observed Effects of Changes in Groundwater Flow on a Borehole Heat Exchanger of a Large Scale Ground Coupled Heat Pump System

Abstract

A study was completed comparing the effectiveness of a borehole heat exchanger (BHE) within a large scale closed-loop geothermal system to changes in groundwater flow, as a result of periodic pumping of a large municipal well. The BHE studied consists of 144 geoexchange boreholes drilled to a depth of 122 m into karstic bedrock of the Ozark Aquifer. Estimated groundwater flows rates range from 15 to 1.1 x 10-3 m/year were measured, and the effectiveness of the BHE during pumping was calculated to understand the effects of groundwater flow on the system. Changes in the BHE effectiveness under varying flow rates were compared to estimates from previous study estimates with changes in aquifer saturation. Overall, the variations in aquifer saturation tended to have the greatest influence on the effectiveness of the BHE.

Department(s)

Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

Borehole heat exchanger; Geothermal energy; Geothermal system; Ground-coupled heat pumps; Groundwater; Groundwater flow

International Standard Serial Number (ISSN)

0375-6505

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2018 Elsevier Ltd, All rights reserved.

Publication Date

01 Jul 2018

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