ABSTRACT
In this chapter, we establish a consistent procedure for deriving mathematical models capable of simulating transient and steady-state heat transfer in commonly utilized geothermal boreholes heat exchangers. We begin by formulating the heat equation of a multiple conductive-convective continuum. Then we generalize the procedure to establish heat equations of typical borehole heat exchangers, namely, single U-tube borehole heat exchanger (1U), double U-tube (2U), coaxial with annular (CXA) and coaxial with centered inlet (CXC).
