This paper presents the analytical heat transfer models for the vertical ground heat exchangers (GHEs) and the attendant program named "GEOSTAR" developed for use in design and simulation of vertical GHEs. The program used spatial superposition for multiple boreholes and sequential temporal superposition principles to account for time-varying loads. Coupled with the models of the heat pump and building loads, the GEOSTAR can predict time-varying heat pump energy consumption, heat transfer rates of GHEs, and other variables of interest. Finally, the program is applied to design an existing GCHP project and to simulate the system performance. The results demonstrate the usefulness of the simulation model and attendant program as a tool for designing GCHP systems.
Cui, P., Sun, C., Diao, N., & Fang, Z. (2015). Simulation Modelling and Design Optimization of Vertical Ground Heat Exchanger-GEOSTAR Program. In Procedia Engineering (Vol. 121, pp. 906–914). Elsevier Ltd. https://doi.org/10.1016/j.proeng.2015.09.048