Comparative Heat Transfer Efficiency Study of Coaxial and U-loop Boreholes

Jun Wang
April 2014
GSTF Journal of Engineering Technology;Apr2014, Vol. 2 Issue 4, p1
Academic Journal
This paper presents the results of comparative heat transfer efficiency study based on in situ full scale tests conducted on conventional U-loop borehole heat exchangers (BHE) and a coaxial BHE. The results show that the coaxial BHE has considerably higher heat transfer efficiency, while consuming less pumping power than the U-loop's. The implication of a high efficiency BHE on reducing borehole loop length and initial investment cost is also discussed. It is concluded that the higher efficiency coaxial BHE has the potential to reduce borehole length 30% to 50%.


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