Influence of groundwater flow on the ground heat exchanger performance and ground temperature distributions: A comprehensive review of analytical, numerical and experimental studies. (March 2022)

• Record Type: Journal Article
• Authors: Jia, G.S.; Ma, Z.D.; Xia, Z.H.; Wang, J.W.; Zhang, Y.P.; Jin, L.W.
• Is Part Of: Geothermics. Volume 100(2022)
• Publication Date: 2022-03
• Subjects: Groundwater flow -- Ground heat exchanger performance -- Ground temperature distribution -- Analytical models -- Numerical methods -- Experimental studies; 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.2021.102342
• Languages: English
• ISSNs: 0375-6505

Abstract

Highlights: Influence of groundwater flow on the ground heat exchanger is reviewed. Characteristics of analytical, numerical and experimental approaches are summarized. Groundwater flow benefits the ground temperature recovery and heat exchanger performance. The impact extent depends on the thickness, depth and flow rate of the aquifer. Ignoring the groundwater flow would cause nonnegligible prediction errors. Abstract: The performance of the ground heat exchanger (GHE) possesses a pivotal role in the geothermal exploitation. In recent years, a growing body of literature that recognizes the importance of groundwater flow has been presented. This article reviewed the literature dealing with the impact of groundwater flow on the GHE performance and ground temperature distribution, which were classified by analytical, numerical and experimental approaches. The characteristics of the three approaches were summarized respectively. Various GHE configurations, including U-tube, double U-tube, spiral tube, tunnel lining, horizontal spiral GHEs and GHE groups, were involved in the discussion. It was found that the groundwater flow is beneficial to the ground temperature recovery and improves the GHE heat exchange rate. The effective thermal conductivities of rocks and soils, and borehole resistances, are also affected by groundwater flow. The impact extent depends mainly on the thickness, depth and flow rate of the aquifer layer. The discussion on the collected literature demonstrated that ignoring the groundwater flow would cause non-negligible prediction errors in the evaluation of GHEs. Based on the analysis of the characteristics and applicabilities of the discussed models and methods, this review is expected to provide a more comprehensive reference for promoting the utilization of geothermal energy by GHEs.