Freeze damage of grouting materials used for borehole heat exchangers
Dr. Selçuk Erol
Petroleum and Natural Gas Department, Middle East Technical University.
As an alternative and renewable energy source, shallow geothermal energy evolving as one of the most popular energy sources, and the ground source heat pump (GSHP) systems are the most frequent applications for extracting energy from the shallow subsurface. For the heating purposes of buildings, the closed-loop GSHP systems can be operated below the freezing point of water with an anti-freeze mixture through the installed borehole heat exchangers (BHE) in the ground. During the operations, the BHE is exposed to thermal stresses due to heat loading that triggers the freezing-induced ice pressure damaging the grouting material. In this study, the freezing impact on BHEs is investigated numerically and experimentally. According to the measurements and theoretical calculation results, the effective tangential stress induced by the frozen pore water pressure causes the crack development and agrees with the crack patterns. It is concluded that the porosity, permeability, and saturation ratio play a significant role in the grout failure upon freezing.
Selçuk Erol is a researcher of Petroleum and Natural Gas Engineering at the Middle East Technical University (METU), Ankara, Turkey. He obtained his BSc. degree in geophysics at Ankara University (Turkey) in 2006, his MSc. degree in applied geosciences at Tübingen University (Germany) in 2011, and his Ph.D. degree at Brussels University (Belgium) in 2015. Before joining METU, Selçuk Erol was a postdoc researcher affiliated both at the KU Leuven University and at the Flemish Institute for Technological Research (VITO NV) in Belgium between 2016 and 2019.
Place: MS Teams
Date: 24 March 2022; Thursday@11:00-12:00