A computational model using the finite-difference method was established to simulate a vertical U-tube ground-coupled heat exchanger peripheral to a heat pump system. Under careful assumptions, a double two-dimensional cylindrical coordinate system was introduced in constructing the model. Thus, the problem was converted from a three-dimensional transient heat transfer problem into a two-dimensional transient heat transfer problem. Both the validity of the simulation and the economisation of the computational time were important considerations in the development of this model. An experiment was conducted to validate the model. Several simulation runs with different values of model parameters were conducted, and the results agreed with experimental data, with only about a 0.2% to 5% discrepancy for a 160-minute simulation. This new model may have practical value in aiding design tasks for a ground-coupled heat exchanger.

KEYWORDS: computers, models, calculating, soil, heat exchangers, heat flow, experiment, validating, designing, accuracy, soil heat pumps.