Thermal Response Testing Results of Different Types of Borehole Heat Exchangers: An Analysis and Comparison of Interpretation Methods

Autor: Angelo Zarrella, Giuseppe Emmi, Samantha Graci, Michele De Carli, Matteo Cultrera, Giorgia Dalla Santa, Antonio Galgaro, David Bertermann, Johannes Müller, Luc Pockelé, Giulia Mezzasalma, Davide Righini, Mario Psyk, Adriana Bernardi
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Energies, Vol 10, Iss 6, p 801 (2017)
Druh dokumentu: article
ISSN: 1996-1073
DOI: 10.3390/en10060801
Popis: The design phase of ground source heat pump systems is an extremely important one as many of the decisions made at that time can affect the system’s energy performance as well as installation and operating costs. The current study examined the interpretation of thermal response testing measurements used to evaluate the equivalent ground thermal conductivity and thus to design the system. All the measurements were taken at the same geological site located in Molinella, Bologna (Italy) where a variety of borehole heat exchangers (BHEs) had been installed and investigated within the project Cheap-GSHPs (Cheap and efficient application of reliable Ground Source Heat exchangers and Pumps) of the European Union’s Horizon 2020 research and innovation program. The measurements were initially analyzed in accordance with the common interpretation based on the first-order approximation of the solution for the infinite line source model and then by utilizing the complete solutions of both the infinite line and cylinder source models. An inverse numerical approach based on a detailed model that considers the current geometry of the BHE and the axial heat transfer as well as the effect of weather on the ground surface was also used. Study findings revealed that the best result was generally obtained using the inverse numerical interpretation.
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