de
New backfilling concept for BHE's
Lead Management Subproject Leader
B.Eng. Frank Burkhardt (frank@burkhardt-bohrungen.de)
Participating Partners
Quality assurance is becoming increasingly important in the construction phase of borehole heat exchangers. The warranty and verifiability of the backfilling quality are of particular interest. Due to prominent damage events, an automatically generated grouting protocol is prescribed in the state of Baden-Württemberg (Germany). Other federal states in Germany, e.g. Hessen, are preparing similar requirements.
There are different measuring concepts, which enable an automatically generated grouting protocol. For the determination of the volume flow rate, an electromagnetic flow meter (EMF) is used in these methods. With an EMF, however, only the flow rate can be determined, but not the rheological and physical properties of the suspensions. The essential physical and rheological properties can be determined automatically with a special coriolis mass flow meter. Therefore, the use of a coriolis mass flow meter provides important additional information during construction. Due to the simultaneous recording of volume flow, density, temperature and viscosity, improper suspensions can be detected automatically probably without additional measurements. If the mixed batch is also circulated in advance via a bypass solution, characteristic values can be analysed and checked before the batch is injected into the subsoil. In this way, complete documentation is obtained without great effort and with a guarantee of the required backfilling parameters.
- Construction of the measurement concept
- Testing of the backfilling measurement concept
- Evaluation of the new backfilling measurement concept
