3-D simulation of heat transfer rate in geothermal pile-foundation heat exchangers with spiral pipe configuration

This paper investigates a recently developed method of pipe construction with vertical Spiral-shaped configuration in geothermal pile-foundation heat exchangers for analyzing thermal performance compare to other pipe configurations such as 1-U-shaped and 1-W-shaped in cooling mode of water. Heat transfer rate and temperature distribution in pile-foundation have been simulated and computed. Three pitch sizes for spiral configuration have been considered, simulated and compared to each other for detecting the best performance in heat transfer rate. Furthermore, comparison between Spiral-shaped, 1-U-shaped and 1-W-shaped has been conducted for recognizing the best performance in heat transfer rate and efficiency. Spiral-shaped pile-foundations have been simulated in large scale plant for acquiring better performance in cooling mode with two different connections, serially and parallel. The best pipe configuration inside the pile-foundation regarding the results is spiral-shaped and the best connection is serial connection. (C) 2015 Elsevier Ltd. All rights reserved.