Parametric Study of the Pressure Distribution in a Confined Aquifer Employed for Seasonal Thermal Energy Storage

Authors

Center of Excellence in Energy Conversion (CEEC), School of Mechanical Engineering,‎ Sharif University of Technology, P.O. Box 11155-9567, Tehran, Iran‎

Abstract

Aquifers are underground porous formations containing water. Confined aquifers are formations surrounded by two impermeable layers. These aquifers are suitable for seasonal thermal energy storage. The objective of this research is a parametric study of the pressure distribution in an aquifer to be employed for thermal energy storage for air-conditioning of a building complex. In design of an aquifer thermal energy storage (ATES), a realistic model is needed to predict the aquifer’s behavior. Here, the effects of operating parameters on pressure distribution are investigated through a three-dimensional finite difference model. In an ATES, heat transfer occurs through both convection and conduction. The convective heat transfer in ATES occurs because of pressure gradient. Therefore, knowledge of the effects of various parameters on pressure distribution is necessary. These parameters are: groundwater natural flow, porosity and permeability of the aquifer, injection and withdrawal rates from wells, number and the arrangements (being linear, triangular or rectangular) of injection and withdrawal wells. It has been found that the variation of the pressure drop inside the aquifer with increasing permeability is very considerable in comparison with other parameters. Moreover, a validation is performed by using the Fluent software to verify the accuracy of the developed method.

Keywords