Long-Term Thermal Performance of Group of Energy Piles in Unsaturated Soils under Cyclic Thermal Loading

Abubakar Kawuwa Sani and Rao Martand Singh
Additional contact information
Abubakar Kawuwa Sani: Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, UK
Rao Martand Singh: Department of Civil and Environmental Engineering, Norwegian University of Science & Technology, (NTNU), 7034 Trondheim, Norway

Energies, 2021, vol. 14, issue 14, 1-28

Abstract: Geothermal energy piles (GEPs) are an environmentally friendly heat exchange technology that dualizes the role of the structural foundation pile for load support and in meeting the building heating/cooling need. Energy loops made from high-density polyethylene, which allow heat carrier fluid circulation, are fitted into the pile foundation elements to extract or inject and store heat energy in the soil surrounding the pile. This paper reports the results of a numerical study investigating the long-term behaviour of a group of energy piles embedded in unsaturated soils (sand and clay) under continuous cyclic heating and cooling load. Additionally, two scenarios were investigated where: (1) the whole GEPs were heated and cooled collectively; (2) alternate piles were heated and cooled. It was found that the trend of temperature magnitude at all the observed locations decreases with time as a result of the continuous heating and cooling cycles. Furthermore, subjecting alternate GEPs to the heating and cooling cycles result in lower temperature development in comparison to thermally activating all the GEPs in the group. This is attributed to the applied thermal load, which is 0.5 times that considered in the first case. However, this might not be the case where equal thermal load is applied on the GEPs in the two cases investigated.

Keywords: ground heat exchanger; heat flux; numerical modelling; unsaturated soils; energy pile group; long-term performance; thermal performance (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2021
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.mdpi.com/1996-1073/14/14/4122/pdf (application/pdf)
https://www.mdpi.com/1996-1073/14/14/4122/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:14:y:2021:i:14:p:4122-:d:590719

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().