RECOVERY TIMES AFTER THERMAL RESPONSE TESTS ON VERTICAL BOREHOLE HEAT EXCHANGERS
Paper in proceedings, 2011

The design of a ground source heat pump system requires accurate knowledge of properties, such as ground thermal conductivity and borehole thermal resistance. These properties are often determined using an in-situ thermal response test of a pilot borehole. These tests are sometimes interrupted by unexpected circumstances and occasionally a retest is required. For a retest to be conducted, the ground temperature must return to within 0.1-0.3 K of the initial undisturbed ground temperature. This paper addresses the issue of borehole retesting and reports on a systematic series of thermal response tests conducted to study the times needed for the ground temperature to return to within 0.3 K of the pre-test ground temperature. Tests were conducted using various heat injection rates and different time durations. Following a test, the development of ground temperature was studied for up to 2-3 months. A mathematical model was used to validate the experimentally measured ground temperatures and to extend the results to other testing conditions.

Author

Saqib Javed

Chalmers, Energy and Environment, Building Services Engineering

Johan Claesson

Chalmers, Civil and Environmental Engineering, Building Technology

Richard Beier

Proceedings of 23rd IIR International Congress of Refrigeration (ICR2011), Prague, Czech Republic.

Areas of Advance

Energy

Subject Categories

Building Technologies

More information

Created

10/7/2017