A three-dimensional full-scale model for predicting the performance of deep-buried ground heat exchanger considering groundwater flow

Abstract It is critical to precisely determine the performance of deep-buried ground heat exchangers involving different geological layers in engineering projects geothermal energy utilization. Compared existing approaches solving only conduction between exchanger and surrounding based on two-dimensional model, this paper established a three-dimensional full-scale coaxial model containing both aquifer aquifuge groundwater effect. The convective transfer pipes was calculated using empirical correlation Nusselt number improve computation efficiency. velocity governing equation assumed be constant along with horizontal direction further simplify computation. developed method applied 2800 m 2600 depth conditions, validated by field test published data. relative errors are less than 6.9%. thermal influence ranges layer close asymmetric about circumferential direction. results demonstrated that necessary for accurately evaluating when there migration.