Thermal response testing for ground source heat pump systems - An historical review
Review article, 2015

When designing ground heat exchangers used with ground source heat pump systems, a critical design property is the thermal conductivity of the ground. Thermal response tests are used to measure the site-specific thermal conductivity and are also used to measure the thermal resistance of a borehole heat exchanger as installed. Thermal response tests are commonly used today for design of multiple borehole ground heat exchangers, where knowledge of the ground thermal properties can help avoid undersizing of ground heat exchangers, leading to poor system performance, and oversizing of ground heat exchangers, leading to overly costly systems. This review covers the development of the mathematical and numerical analysis procedures, development of the hardware and test procedures, and validation of the results. We take a historical perspective, going as far back as Lord Kelvin's treatment of transient heat conduction problems in the 1880s, further development of which allowed analysis of conductivity measurements from transient needle probes by the 1950s. We focus on development of test rigs and test procedures in the 1980s and 1990s and validation of the measurements. More recent developments are covered throughout the review.

Thermal response tests

Ground source heat pump systems

Thermal conductivity

In situ measurements

Ground heat exchangers

Author

Jeff Spitler

Chalmers, Civil and Environmental Engineering, Building Services Engineering

Swedish Centre for Shallow Geothermal Energy

S.E.A. Gehlin

Swedish Centre for Shallow Geothermal Energy

Renewable and Sustainable Energy Reviews

1364-0321 (ISSN) 18790690 (eISSN)

Vol. 50 1125-1137

Subject Categories

Energy Engineering

DOI

10.1016/j.rser.2015.05.061

More information

Latest update

2/4/2022 2