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| Titel |
The geothermal potential of the Campania volcanic district and new heat exchanger technologies for exploitation of highly urbanised areas. |
| VerfasserIn |
S. Carlino, R. Somma, A. Troiano, M. G. Di Giuseppe, C. Troise, G. De Natale |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250068048
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| Zusammenfassung |
| The geothermal research in Campania region (Italy), started since the 1930, and continued
until the ’80 by the SAFEN, ENEL and AGIP companies. Such exploration activity
highlighted that most of the volcanic districts of the Campania Region have a very high
geothermal gradient and heat flow. In particular, inside the Campi Flegrei caldera and at
Ischia island the geothermal gradient measured inside the deep wells reaches temperatures
above 100Ë C between few tens and few hundreds of metres of depth, while the heat
flow varies between 120-160 mWm-2 at Agnano and Mofete (Campi Flegrei main
drill sites) to more than 500 mWm-2 at Ischia island (south-western sector). A
general review of the available literature data (temperature at depth, stratigraphic
sections, logs etc.) of the deep wells (down to 3 km b.s.l.) allowed us to quantify the
geothermal potential (thermal and electric) of such district. The geothermal potential
is about 6 GWy for the Campi Flegrei (Mofete and S. Vito sectors) and 11 GWy
for the Ischia island (south-western sector) showing a geothermal reservoir with
water and vapour dominant respectively. This results in strong potential interest for
economic exploitation of the geothermal resource, both in the range of low-medium
enthalpy at few hundreds of meters depth and of high enthalpy at depths of 1-2
km.
In this study we try to model the effectiveness of new technologies of boreholes heat
exchangers, which would allow to avoid fluid withdrawal, then strongly decreasing the
environmental impact. The proposed technology consists of a double-pipe placed in a
borehole heat exchange that can work coupled with an ORC. The two pipes, one inside the
other, are located in the well in order to transfer the thermal energy to the working fluid
during the descent in the external pipe and then go back through the internal pipe properly
isolated.
We propose a complete design of the borehole heat exchangers. The design activity is
performed on a theoretical basis, and mathematical/physical model are also derived. Besides
simple boreholes, heat exchange could be enhanced by fracturing rocks around the well;
theoretical simulations for this case are also presented. |
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