A Tool for the Optimal Design of Climate Resilient Thermal Energy Networks. Part 3: The Ground Loop Model

This paper illustrates the development of the Ground Loop module within an open-source tool aimed at designing fifth generation District Heating and Cooling Systems based on Ground Coupled Heat Pumps. The module performs the sizing of the closed loop ground heat exchanger on the basis of the ASHRAE method, turns it into a compact rectangular layout and then calculates the corresponding thermal response. The g-function of the borefield is obtained with finite line source models, differentiating between the case of null and non-null groundwater flow. To demonstrate the potential of the module, the case study of a community scale borefield is simulated, and the impact of groundwater velocity and direction is discussed.