Geologic and thermal conductivity analysis based on geophysical test and combined modeling

Shihao Dong, Yuelong Yu, Bingxue Li and Long Ni

Energy, 2024, vol. 310, issue C

Abstract: Strata thermal conductivity (λe) influences efficiency of medium-depth ground heat exchangers. However, a systematic approach to the acquisition of λe is still lacking. Hence, stratigraphic heat conduction was analyzed using geophysical test in Shenyang, combined with composite modeling. Cenozoic strata (0–730m) exhibited an average λe of 1.32 W·m−1·K−1 due to higher porosity and mud content; Archaean (730–2500m) strata displayed a higher λe of 2.80 W·m−1·K−1, due to dense quartz sandstone with lower porosity and mud content. The CBHE in Shenyang can achieve excellent heat extraction relying on good thermal conduction. Spearman correlation revealed strong negative correlations between λe and acoustic time difference, permeability, and porosity, while positive correlations were observed with depth, resistivity, wave speed, and rock skeleton. Higher rock skeleton thermal conductivity intensified the decrement effect of mud content on λe, while higher mud content diminished the enhancement effect of rock skeleton thermal conductivity. As porosity increased, the decline in λe slowed, particularly pronounced at higher saturation levels. λe exhibited a gradual decrease with temperature, with a more notable change rate observed at lower porosity levels. Principles for enhancing thermal conduction were elucidated through a three-phase analysis. These findings provide foundation for the study and design of medium-depth boreholes.

Keywords: Ground heat exchanger; Combined model; Strata thermal conductivity; Geophysical survey (search for similar items in EconPapers)
Date: 2024
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0360544224030111
Full text for ScienceDirect subscribers only

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:eee:energy:v:310:y:2024:i:c:s0360544224030111

DOI: 10.1016/j.energy.2024.133235

Access Statistics for this article

Energy is currently edited by Henrik Lund and Mark J. Kaiser

More articles in Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().