Implementing an effective finite difference formulation for borehole heat exchangers into a heat and mass transport code

Abstract

We present an effective finite difference formulation for implementing multiple ground heat exchangers (GHE) in the 3-D coupled heat and flow transport model SHEMAT (Simulator of Heat and Mass Transport, Clauser, 2003) The GHE with arbitrary length can be coaxial as well as U-shaped. The new approach does not require the fine discretization of the GHE assemblage since it considers heat transport between fluid and the soil through pipes and grout via thermal resistances. Therefore, the simulation time can be significantly reduced.