Development and validation of a computationally efficient hybrid model for temporal high‐resolution simulations of geothermal bore fields

International Journal for Numerical and Analytical Methods in Geomechanics, vol. 46, pp. 2792–2813

Abstract

Abstract This paper presents a hybrid simulation approach for 1U‐, 2U‐ and coaxial single, and field of, borehole heat exchangers. We implement a novel combination of existing solutions for the simulation of heat transfer processes within the borehole and the surrounding ground. The heat transfer in the ground is modelled with a combination of analytically determined g‐functions, the borehole models utilize thermal resistance capacity models and the finite volume method. Critically, we improve the computational efficiency of long‐term simulations by sub‐dividing the time scale into multiple periods, where the influence of past periods on future periods is calculated using the fast Fourier transform (FFT). The accuracy and efficiency of the proposed method is validated against single borehole numerical models and a 40 bore field case study. The method achieves computational times reductions of over 90% in some cases, with greater improvement as the simulation time increases.

Authors 3

1. Stephan Düber corresponding Aachen Institute of Geomechanics and Underground Technology

   RWTH Aachen University · The University of Melbourne

   Affiliation as printed

   Department of Infrastructure Engineering The University of Melbourne Parkville Australia

   Institute of Geomechanics and Underground Technology RWTH Aachen University Aachen Germany

   Department of Infrastructure Engineering, The University of Melbourne, Parkville, Australia

   Institute of Geomechanics and Underground Technology, RWTH Aachen University, Aachen, Germany

2. Martin Ziegler
   Affiliation as printed

   Ziegler und Aulbach Ingenieurgesellschaft mbH Managing Director, Professor (Emeritus) Ziegler und Aulbach Ingenieurgesellschaft mbH Aschaffenburg Germany

   Ziegler und Aulbach Ingenieurgesellschaft mbH, Managing Director, Professor (Emeritus), Ziegler und Aulbach Ingenieurgesellschaft mbH, Aschaffenburg, Germany

3. Raúl Fuentes Aachen Institute of Geomechanics and Underground Technology

   RWTH Aachen University

   Affiliation as printed

   Institute of Geomechanics and Underground Technology RWTH Aachen University Aachen Germany

   Institute of Geomechanics and Underground Technology, RWTH Aachen University, Aachen, Germany