Investigation of buoyancy effects on heat transfer between a vertical borehole heat exchanger and the ground

摘要: a b s t r c In this paper, the heat transfer from vertical borehole exchanger in presence of groundwater is investigated using general convection–conduction model. The model can be used for estimating required length given constant load locations with or without groundwater. All thermal resistances involved process between and surrounding ground are taken into consideration. addition, effect surface to ambient investigated. A comparative case study presented illustrate differences based on proposed comparison other methods that conduction only mode transfer. It found natural convection arises increases flux surface. Consequently, decreases by about 50% at soil permeability 5 × 10 −9 m 2 . convective type reduces 10% compared an adiabatic assumption.