Numerical Analysis on the Behavior of Energy Pile using Coil Type Heat Exchanger

摘要

Conventional energy pile includes vertical closed loop U-type heat exchanger in grout body, andrnconsequently, heat exchange behavior of the energy pile becomes more complex than typical GSHPs buried in thernground, owing to existence of grout surrounding the U-tube. Moreover, when coil-type heat exchanger is used inrnthe energy pile to enhance heat exchange efficiency, current analytical methods, i.e. line-source model orrncylindrical source model, may not predict realistic heat exchange performance because of intricate geometry of therncoil-tube. Hence, in this study, a 2-dimensional axisymmetric finite element model with ABAQUS commonrnprogram was developed to simulate realistic heat exchange behavior of coil-type energy pile, where a general formrnof the heat diffusion equation applicable to the energy pile was considered. The numerical model was applied tornsimulate thermal response tests conducted in the model chamber, and its validity was investigated by comparing thernpredictions with the test measurements.