Thermal performance evaluation and parametric study of a horizontal ground heat exchanger. (March 2016)

• Record Type: Journal Article
• Authors: Kim, Min-Jun; Lee, Seung-Rae; Yoon, Seok; Go, Gyu-Hyun
• Is Part Of: Geothermics. Volume 60(2016:Mar.)
• Page Start: 134
• Page End: 143
• Publication Date: 2016-03
• Subjects: Ground source heat pump -- Horizontal heat exchanger -- Horizontal spiral coil type; Hydrogeology -- Periodicals; Geothermal resources -- Periodicals; Énergie géothermique -- Périodiques; GEOTHERMAL ENGINEERING; GEOTHERMAL ENERGY; GEOTHERMAL EXPLORATION; Geothermal resources; Hydrogeology; Periodicals; Electronic journals; 621.44
• DOI: 10.1016/j.geothermics.2015.12.009
• Languages: English
• ISSNs: 0375-6505

Abstract

Highlights: A numerical model verified with the experimental data was developed. Performance of the horizontal coil-type GHE was better than that of the slinky-type GHE. Soil thermal conductivity is the main factor determining the heat exchange rate of a GHE. The pipe diameter does not have any effect on the GHE performance. Abstract: A ground-source heat pump (GSHP) system uses a relatively constant ground temperature to emit heat in summer and to obtain heat during winter for heating and cooling energy. Among diverse GSHP systems, in designing a closed horizontal system, it is important to accurately estimate the thermal performance of the horizontal ground heat exchanger (GHE). Therefore, in this study, we investigated the performance of a horizontal GHE via experiments and numerical analyses. Thermal response tests (TRTs) were conducted to evaluate heat exchange rates by using horizontal slinky- and spiral-coil-type GHEs installed in a 5 m × 1 m × 1 m steel box filled with dried Joomunjin sand. Numerical analyses were conducted for verification with experimental results and a parametric study of affecting parameters on horizontal GHE. The results of the TRTs and the numerical analyses were well matched, and coil-type GHEs were found to perform better than the horizontal slinky-type GHEs. Our results show that, among horizontal GHE design parameters, GHE type and soil thermal conductivity are the main factors to determine the heat exchange rate of a GHE, whereas the pipe diameter does not have any effect on the GHE performance.