Numerical Investigation on the Performance of Horizontal Helical-Coil-Type Backfill Heat Exchangers with Different Configurations in Mine Stopes

Bo Zhang (), Long Shi, Wenxuan Zhang, Chao Huan, Yujiao Zhao and Jingyu Wang
Additional contact information
Bo Zhang: College of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
Long Shi: College of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
Wenxuan Zhang: College of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
Chao Huan: College of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
Yujiao Zhao: College of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
Jingyu Wang: College of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, China

Mathematics, 2023, vol. 11, issue 19, 1-21

Abstract: The application of ground heat exchanger technology in backfill mines can actualize subterranean heat storage, which is one of the most effective solutions for addressing solar energy faults such as intermittence and fluctuation. This paper provides a 3D unsteady heat transfer numerical model for full-size horizontal backfill heat exchangers (BFHEs) with five configurations in a mining layer of a metal mine by using a COMSOL environment. In order to ensure the fairness of the comparative analysis, the pipes of BFHEs studied have the same heat exchange surface area. By comparing and evaluating the heat storage/release characteristics of BFHEs in continuous operation for three years, it was discovered that the helical pipe with serpentine layout may effectively enhance the performance of BFHEs. Compared with the traditional SS BFHEs, the heat storage capacity of the S-FH type is significantly increased by 21.7%, followed by the SA-FH type, which is increased by 11.1%, while the performances of U-DH and SH type are considerably lowered. Also, the impact of the critical structural factors (pitch length and pitch diameter) was further studied using the normalized parameters C 1 and C 2 based on the inner diameter of the pipe. It is discovered that BFHEs should be distributed in a pipe with a lower C 1 , and increasing C 2 encourages BFHEs to increase the storaged/released heat of BFHEs. By comparatively analysing the effect of thermal conductivity, it is found that the positive effects of thermal conductivity on the performance of SH, U-DH, SA-FH, and S-FH type BFHEs are found to decrease successively. This work proposes a strategy for improving the heat storage and release potential of BFHEs in terms of optimal pipe arrangement.

Keywords: backfill heat exchangers; horizontal helical pipe; thermal energy storage; heat storage and release performance (search for similar items in EconPapers)
JEL-codes: C (search for similar items in EconPapers)
Date: 2023
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2227-7390/11/19/4173/pdf (application/pdf)
https://www.mdpi.com/2227-7390/11/19/4173/ (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:jmathe:v:11:y:2023:i:19:p:4173-:d:1253900

Access Statistics for this article

Mathematics is currently edited by Ms. Emma He

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