Thermal Characteristics of Slinky-Coil Ground Heat Exchanger with Discrete Double Inclined Ribs

Teguh Hady Ariwibowo and Akio Miyara
Additional contact information
Teguh Hady Ariwibowo: Graduate School of Science and Engineering, Saga University, 1 Honjo-machi, Saga 840-8502, Japan
Akio Miyara: Department of Mechanical Engineering, Saga University, 1 Honjo-machi, Saga 840-8502, Japan

Resources, 2020, vol. 9, issue 9, 1-17

Abstract: The slinky ground heat exchanger (GHE) is the most widely utilized horizontal-type GHE, however, this GHE has a low curvature coil. The GHE has poor thermal mixing, especially at a low flowrate. At this flowrate, the coil heat exchanger has similar performance to a straight tube heat exchanger. Discrete double-inclined ribs (DDIR) are well known for their good thermal mixing by generating a vortex in straight tubes. In this paper, a numerical analysis of thermal performance for the plain coil and DDIR coil is discussed. It was found that the thermal performance of the DDIR coil was slightly higher than that of the plain coil in laminar flow. In turbulent flow, the DDIR coil was superior to the plain coil only in the first 149-min operation. The first 60-min analysis shows that in laminar flow, the average heat transfer rate in the plain coil is 59 W/m and in the DDIR coil is 60.1 W/m. In turbulent flow, the average heat transfer rate is 62 W/m, and the plain coil is 62.3 W/m. The copper DDIR coil material produced a better heat transfer rate than that of the composite and High-Density Polyethylene (HDPE). Sandy clay has the highest heat transfer rate. The influence of ground thermal conductivity on the performance of the GHE is more dominant than convection in the DDIR coil.

Keywords: discrete double-inclined ribs; low curvature coil; vortex generator; ground heat exchanger (search for similar items in EconPapers)
JEL-codes: Q1 Q2 Q3 Q4 Q5 (search for similar items in EconPapers)
Date: 2020
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.mdpi.com/2079-9276/9/9/105/pdf (application/pdf)
https://www.mdpi.com/2079-9276/9/9/105/ (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:jresou:v:9:y:2020:i:9:p:105-:d:406251

Access Statistics for this article

Resources is currently edited by Ms. Donchian Ma

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