Data di Pubblicazione:
2015
Citazione:
Influences on the thermal efficiency of energy piles / F. Cecinato, F. Loveridge. - In: ENERGY. - ISSN 0360-5442. - 82(2015), pp. 1021-1033. [10.1016/j.energy.2015.02.001]
Abstract:
Energy piles have recently emerged as a viable alternative to borehole heat exchangers, but their energy
efficiency has so far seen little research. In this work, a finite element numerical model is developed for
the accurate 3D analysis of transient diffusive and convective heat exchange phenomena taking place in
geothermal structures. The model is validated by reproducing both the outcome of a thermal response
test carried out on a test pile, and the average response of the linear heat source analytical solution. Then,
the model is employed to carry out a parametric analysis to identify the key factors in maximising the
pile energy efficiency. It is shown that the most influential design parameter is the number of pipes,
which can be more conveniently increased, within a reasonable range, compared to increasing the pile
dimensions. The influence of changing pile length, concrete conductivity, pile diameter and concrete
cover are also discussed in light of their energetic implications. Counter to engineering intuition, the fluid
flowrate does not emerge as important in energy efficiency, provided it is sufficient to ensure turbulent
flow. The model presented in this paper can be easily adapted to the detailed study of other types of
geothermal structures.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Energy piles; Geothermal; Thermal efficiency; Thermal response test; Numerical modelling; Convection-diffusion
Elenco autori:
F. Cecinato, F. Loveridge
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