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http://dx.doi.org/10.9720/kseg.2014.4.487

Numerical Simulations for Optimal Utilization of Geothermal Energy under Groundwater-bearing Conditions  

Kim, Jin-Sung (Rural Research Institute, Korea Rural Community Corporation)
Cha, Jang-Hwan (GeoGreen21 Co., Ltd.)
Song, Sung-Ho (Rural Research Institute, Korea Rural Community Corporation)
Jeong, Gyo-Cheol (Dept. of Earth and Environmental Sciences, Andong National University)
Publication Information
The Journal of Engineering Geology / v.24, no.4, 2014 , pp. 487-499 More about this Journal
Abstract
While the vertical open type of heat exchanger is more effective in areas of abundant groundwater, and is becoming more widely used, the heat exchanger most commonly used in geothermal heating and cooling systems in Korea is the vertical closed loop type. In this study, we performed numerical simulations of the optimal utilization of geothermal energy based on the hydrogeological and thermal properties to evaluate the efficiency of the vertical open type in areas of abundant groundwater supply. The first simulation indicated that the vertical open type using groundwater directly is more efficient than the vertical closed loop type in areas of abundant groundwater. Furthermore, a doublet system with separated injection and extraction wells was more efficient because the temperature difference (${\Delta}$) between the injection and extraction water generated by heat exchange with the ground is large. In the second simulation, we performed additional numerical simulations of the optimal utilization of geothermal energy that incorporated heat transfer, distance, flow rate, and groundwater hydraulic gradient targeting a single well, SCW (standing column well), and doublet. We present a flow diagram that can be used to select the optimal type of heat exchanger based on these simulation results. The results of this study indicate that it is necessary to examine the adequacy of the geothermal energy utilization system based on the hydrogeological and thermal properties of the area concerned, and also on a review of the COP (coefficient of performance) of the geothermal heating and cooling system.
Keywords
geothermal energy; geothermal heating and cooling system; type of heat exchanger; vertical open type; groundwater;
Citations & Related Records
Times Cited By KSCI : 6  (Citation Analysis)
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