Heat-source solutions to heat conduction in anisotropic media with application to pile and borehole ground heat exchangers

Min Li and Alvin C.K. Lai

Applied Energy, 2012, vol. 96, issue C, 458 pages

Abstract: This work analyzes influence of anisotropy of anisotropic soil on the processes of heat transfer by ground heat exchangers used in ground-coupled heat pump systems. First, this paper uses the heat-source theory to develop several explicit exact solutions for heat conduction in anisotropic infinite or semi-infinite media with internal line, cylindrical-surface, or spiral-line sources. These solutions will reduce to common heat-source solutions for isotropic media. Next, these general solutions are applied to borehole ground heat exchangers and energy piles (or pile ground heat exchangers). Then, temperature responses of borehole and pile ground heat exchangers are examined in depth. Especially, the cylindrical-surface source model and the spiral-line source model are compared when applied to energy piles with spiral coils. An interesting result of this comparison is that these two models yield the almost same average temperature at the pile wall, implying these two models should be equivalent for modeling responses of energy piles with spiral coils. However, compared to the cylindrical-surface model, spiral-line model is physically reasonable but is computation-intense. Moreover, the theoretical analysis shows that anisotropy of the medium has little effect on the short-term performance of ground heat exchangers but influences the long-term temperature responses obviously.

Keywords: Anisotropic media; Heat-source solution; Ground heat exchanger; Energy pile; Ground-coupled heat pump system (search for similar items in EconPapers)
Date: 2012
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (31)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0306261912001869
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:appene:v:96:y:2012:i:c:p:451-458

Ordering information: This journal article can be ordered from
http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/bibliographic
http://www.elsevier. ... 405891/bibliographic

DOI: 10.1016/j.apenergy.2012.02.084

Access Statistics for this article

Applied Energy is currently edited by J. Yan

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