Concept, design and testing of an innovative geothermal heat exchanger installed at the Brenner Base Tunnel

The document briefly presents the design, installation and testing of a geoexchangers prototype, exploiting energy through drainage water of the Brenner Base Tunnel system. The prototype was developed by the joint efforts of BBT-SE and the University of Bologna, Department DICAM, employing the synergy of a Master’s thesis work (and working stage) hosted by BBT-SE during the period December 2020 – July 2021 (Spaggiari, 2021). The prototype was called “Smart Flowing” for the intrinsic type of heat exchange process occurring and for its simple design and ease of assembly. It consists in a modular horizontal closed-loop system located into the central drain formed by the invert elements of the exploratory tunnel’s lining. Modules were built outside the tunnel system and later on placed and assembled concurrently to the advancement of the Tunnel Boring Machine. Specific tests, simulating the work of a heat pump conditioning systems in heating and cooling mode, were carried out for a two-month period to prove the reliability and the efficiency of the system. The document is concluded by a preliminary economic and environmental potential assessment of the prototype and some insights about further evolution of the research.