scholarly journals Impacts of borehole heat exchangers (BHEs) on groundwater quality: the role of heat-carrier fluid and borehole grouting

2018 ◽  
Vol 77 (5) ◽  
Author(s):  
Arianna Bucci ◽  
Alessandra Bianco Prevot ◽  
Sandro Buoso ◽  
Domenico Antonio De Luca ◽  
Manuela Lasagna ◽  
...  
Keyword(s):  
Groundwater Quality ◽  
Heat Carrier ◽  
Heat Exchangers ◽  
Carrier Fluid ◽  
Borehole Heat Exchangers

scholarly journals Nanofluid suspensions as heat carrier fluids in single U-tube borehole heat exchangers

2021 ◽  
Vol 2116 (1) ◽  
pp. 012100
Author(s):  
A Jahanbin ◽  
G Semprini ◽  
B Pulvirenti
Keyword(s):  
Thermal Resistance ◽  
Heat Carrier ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Borehole Heat Exchanger ◽  
Carrier Fluid ◽  
Improve Energy Efficiency ◽  
Ground Source ◽  
Borehole Thermal Resistance ◽  
Borehole Heat Exchangers

Abstract The borehole heat exchanger (BHE) is a critical component to improve energy efficiency and decreasing environmental impact of ground-source heat pump systems. The lower thermal resistance of the BHE results in the better thermal performance and/or in the lower required borehole length. In the present study, effects of employing a nanofluid suspension as a heat carrier fluid on the borehole thermal resistance are examined. A 3D transient finite element code is adopted to evaluate thermal comportment of nanofluids with various concentrations in single U-tube borehole heat exchangers and to compare their performance with the conventional circuit fluid. The results show, in presence of nanoparticles, the borehole thermal resistance is reduced to some extent and the BHE renders a better thermal performance. It is also revealed that employing nanoparticle fractions between 0.5% and 2 % are advantageous in order to have an optimal decrement percentage of the thermal resistance.

scholarly journals Simulation-Based Comparison Between the Thermal Behavior of Coaxial and Double U-Tube Borehole Heat Exchangers

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2321 ◽  
Author(s):  
Quaggiotto ◽  
Zarrella ◽  
Emmi ◽  
De Carli ◽  
Pockelé ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
Heat Pump ◽  
Heat Exchangers ◽  
Geothermal Heat ◽  
Pump System ◽  
Carrier Fluid ◽  
Heat Pump System ◽  
Horizon 2020 ◽  
Operating Modes ◽  
Borehole Heat Exchangers

In this study, the thermal behavior of the coaxial and double U borehole heat exchangers was investigated using numerical simulations in both the long- and short-term. As a reference for borehole heat exchanger specifications, the existing coaxial and double U probes of a geothermal heat pump installed within the Horizon 2020 research project named “Cheap GSHPs” were considered. Nine years of simulations revealed that when borehole heat exchangers are subjected to a balanced thermal load, and intermittent operating modes of the ground source heat pump system are set, the coaxial pipes’ configuration provides better thermal performance due to the higher thermal capacitance of the heat-carrier fluid and the lower borehole thermal resistance. The analysis was conducted considering two different types of ground with different thermal conductivity values. As result, the more conductive ground type highlights the higher yield of the coaxial probe.

Borehole Heat Exchangers in aquifers: simulation of the grout material impact

2016 ◽  
Vol 41 ◽  
pp. 268-271
Author(s):  
Luca Alberti ◽  
Adriana Angelotti ◽  
Matteo Antelmi ◽  
Ivana La Licata
Keyword(s):  
Heat Exchangers ◽  
Borehole Heat Exchangers

scholarly journals Low enthalpy geothermal energy: borehole heat exchangers (BHE). Geological and geothermal supervision during active construction in support of the energy certification of buildings - ESBE certification plan

2012 ◽  
Author(s):  
Lorenzo Cadrobbi ◽  
Fioroni Daniele ◽  
Alessandro Bozzoli
Keyword(s):  
Energy Conservation ◽  
Heat Exchangers ◽  
Energy Efficient ◽  
Geothermal Energy ◽  
Energy Requirements ◽  
Effective Coverage ◽  
Correct Execution ◽  
Environmental Technologies ◽  
Borehole Heat Exchangers ◽  
Ongoing Monitoring

This article draws on the experience matured while working with low-enthalpy geothermic installations both in the design and executive phase as well as ongoing monitoring, within the scope of energy conservation as it relates to building and construction. The goal is to illustrate the feasibility of adopting the ESBE certification protocol (Certification of Energy Efficient Low-Enthalpy Probes) aimed at optimizing the harnessing of local geothermic resources to satisfy the energy requirements of a building, measured against the initial investment. It is often the case, in fact, that during the course of a construction project for a given low-enthalpy installation, we verify incompa tibilities with the local geologic and geothermic models, which, if inadequate during construction, can compromise the proper functioning of the installation and its subsequent operation. To this end, the ESBE method, which adheres to the governing environmental regulations, and which takes its cue from technical statutes within the sector, permits us to validate via verification, simulations and tests, the geothermic field probes used in construction in an objective and standardized manner, thereby joining and supporting the most recent protocols for energy certification of buildings (LEED 2010, CASACLIMA 2011, UE 20120/31 Directive). ESBE certification operates through a dedicated Certifying Entity represented by the REET unit (Renewable Energies and Environmental Technologies) of FBK (Bruno Kessler Foundation) of Trento. The results obtained by applying the ESBE method to two concrete cases, relative to two complex geothermic systems, demonstrate how this protocol is able to guarantee, beyond the correct execution in the field of geothermic probes, an effective coverage of the energy requirements of the building during construction adopting the best optimization measures for the probes in keeping with the local geological and geothermic model.

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