Enhanced aquifer thermal energy storage for cooling and heating of Shinshu University building using a nested well system

Abstract

An enhanced aquifer thermal energy storage (ATES) is proposed in this paper in order to provide cooling and heating energy from groundwater to an airconditioning system of a building at Shinshu University. By adopting the enhanced ATES, a nested well system composed of withdrawal and injection wells is under construction in which an upper unconfined aquifer is used to withdraw, inject and store cooling water, and an underlying confined aquifer is used for heating water. A variety of field tests including all-core boring,electrical logging, thermal logging, pumping tests and thermal and salt-water tracer tests has been performed to identify hydrogeologic and thermal properties of the aquifer. Numerical simulations were then conducted by using SWATER (Subsurface Water and Thermal Energy Resources), which is a program for simulating three-dimensional water flow and heat transport in aquifer systems. The numerical results showed that the enhanced ATES is superior to the conventional ATES in terms of recovered thermal energy. © 2011 WIT Press.