Experimental and Computational Performance Comparison Between Different Shallow Ground Heat Exchangers

Abstract

For ground source heat pump applications, shallow ground heat exchangers (SGHEs) are cheaper and easier to apply in comparison with the vertical borehole heat exchangers. The main disadvantage of SGHEs is the requirement for large application area. To decrease the application area and initial cost of the system, different kind of designs are developed for SGHEs. In this study, common and wide used designs (snail, slinky and helix types) are experimentally and computationally investigated and their unit heat transfer rates (HTR) as well as unit cost per HTR values are compared. Results show that snail design is the best if heat transfer rate per unit length is considered while the vertical helix design becomes the best if the application area is considered. On the other hand, if the minimization of initial cost is the target, then slinky design is the best solution. Also unit cost per HTR values of SGHEs are compared with that of vertical borehole heat exchangers. Furthermore long term unit HTR values are computationally predicted and compared.