Aquifer Thermal Energy Storage: development of a simplified model for building and district simulation tools

The main goal of this master thesis is the development of a model of an Aquifer Thermal Energy Storage (ATES) for building and district simulations tools. An ATES system consists of two or more groundwater wells where the storage and recovery of thermal energy is achieved by extraction and injection of water. Usually, the performance study of an ATES requires complex fluid dynamics simulations which have limited capability of integrating energy tools. In the proposed simplified model, which was developed using a MATLAB code, the radial temperature variation of the groundwater is calculated using a finite difference method with a lumped parameters system to solve the transient heat and mass transfer equations in the porous media. The model was validated with measured data retrieved from an ATES system located in Delft (Netherlands). To demonstrate the use of the above mentioned model, a simulation-based case study was carried out by connecting the ATES model with an office building energy model. Thermal loads from the office building simulation have been integrated in the ATES model assuming that the system works with a groundwater heat pump for heating and a heat exchanger for cooling. Simulations were performed under three different climate conditions (Verona, Frankfurt, and Helsinki).