Long-term Performance of a Borehole Heat Exchanger Field Connected to a Multifunctional Office Building

Abstract

We present results of long-term numerical simulations of a large array of borehole heat exchangers (BHE) serving a multifunctional building. Automatically controlled heating and cooling operation has been monitored for a period of over two years. This data set, including groundwater flow, was used for a numerical simulation of the subsurface temperature over a period of ten years. Data from distributed optical temperature sensing (DTS) was used in some of the boreholes for calibrating the simulation results. We see different behaviours of BHEs depending on their specific position. We used the results on the variation of sub-surface temperature with time for optimizing the building’s control regarding the management of the heating and cooling operation mode . With all monitoring and measuring systems in place at the E.ON ERC multifunctional building, the BHE array provides ideal ground-truth for testing long-term numerical simulations for a sustainable and cost reducing operation of such buildings..