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Hamburg
Rheingraben
EON ERC Den
Haag
Australia
India
References
E.ON
Energy Research Center, RWTH University
Optimizing
operations by fiber optics temperature monitoring
The
new main office of the E.ON Energy Research Center (E.ON ERC) is
targeted to test and proof innovative concepts of indoor
climatisation under real user conditions. Part of the heating and
cooling system is the ground heat exchanger field, consisting of
40 probes drilled in a small scale grid down to depths of 100 m.
All heat exchanger probes were installed with additional fibre
optics cables, allowing a continuous temperature monitoring along
the probes.
Geophysica
GmbH was ordered by RWTH university to build a geothermal 3-D
model for the subsurface with all ground heat exchangers
implemented. First, the subsurface was characterized in terms of
thermal and hydraulic properties using
data from laboratory investigations, well logging and thermal
response tests. Gamma ray logging proved to be an important tool
for thermal property prediction. The record of natural
radioactivity was transformed into synthetic thermal conductivity
profiles. Comparing these profiles with the results of the
enhanced geothermal response tests (EGRT) allowed to identify
zones of advective heat transport triggered by groundwater flow.
The
geothermal 3-D model was then calibrated by the fiber optic
records and the performed laboratory studies and well tests. It
was necessary also to consider the variation of surface
temperature during the last 500 years in order to fully describe
the undisturbed temperature field by the model. Finally, the model
was tested and delivered to the client. The model now serves as
basis for ongoing temperature monitoring, carried out n the frame
of a research project. The objective of the project is to use the
measured data of the subsurface and the building in order to
optimize the heat exchanger field operation.
Visualization: 3-D model of the
subsurface with 40 probes implemented. The arrows mark the
groundwater flow at the transition zone of the cretaceous soft
sediments and the underlying dense shales of the paleozoic
basement.
Comparison
of a synthetic thermal property profile based on gamma ray data
with the measured profile of the EGRT (right track). Both
profiles fit in depth sections of conductive heat transport.
Off-sets between the curves point to advective transport of
groundwater flow.
Please
find further information to the E.ON ERC monitoring concept under
following link:
http://www.energieagentur.nrw.de/_database/_data/datainfopool/Pechnig.pdf
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