Master's thesis Andreas Rothe


Development of a dynamic control of a borehole heat exchanger field

Master's thesis Rothe Copyright: EBC

Subject of the thesis at hand is the development of a regulation for a close-to-surface earth probe field of the E.ON Energy Research Center in Aachen. By controlling the volume flow of each probe, it is possible to execute different operations of the probe field. The overall objective is to minimize the differential pressure by regulating the rotational speed of the circulation pump of the field. Thus, an energetic optimal operation is guaranteed.

The hydraulic properties of the probe field are analyzed based on action diagrams and transmission functions. In particular interdependences of volume flows of the single probes and the rotational speed of the circulating pump are analyzed. Based on these analyses control scenarios are developed. Various methods for the development of optimal control parameters are performed. In order to simulate the hydraulic system in a smaller scale a test-bench is constructed, which consists of three probes. The theoretically designed scenarios and control parameters are validated and verified using this test-stand. Following this thesis the control system can be applied to the probe field, because the same control technology is used. The energy flow of each probe can thus be monitored. This leads to the possibility of further research of geothermal energy use at the E.ON Energy Research Center.