期刊名称:International Journal of Energy and Environment
印刷版ISSN:2076-2895
电子版ISSN:2076-2909
出版年度:2011
卷号:2
期号:5
页码:863-870
出版社:International Energy and Environment Foundation (IEEF)
摘要:The hydraulic permeability is a major parameter for modelling the heat transfer of borehole heat exchangers (BHEs) in an aquifer, where the groundwater advection has a significant impact on the thermal performance of BHEs. This paper presented a novel method determining the hydraulic permeability of sand layer using the theory of capillary rise (CR). In this method, based on the observation on the dynamic CR process, the equilibrium height together with the fluid velocity was determined by the steepest descent method to calculate the hydraulic permeability. Further, a laboratory experimental setup was built to measure the hydraulic permeability of screened dry sand with different grain diameters. The measured results were in a good agreement with the predictions by other theoretical models. Finally, the effects of the filling height and immersion depth of the capillary tube on the test accuracy were discussed. The present method can also be applied for other porous materials with the grain diameter of 0.1-0.6mm.