One-dimensional Lattice Boltzmann numerical simulation of a downhole heat exchanger

Abstract

A one-dimensional unsteady heat conduction simulation for downhole heat exchanger (DHE) is established in this paper, and the Lattice Boltzmann Method is used for the numerical simulation. In the model proposed, the influence factors of the temperature gradient with well depth, well pipe diameter, thermal properties of pipe, circulating water flow rate and inlet temperature on the outlet water temperature or heat output have been taken into account. According to the DHE experimental data, a comparison was made between the results of simulation and experiment. The result shows that the model can be used to predict the outlet water temperature of DHE at given conditions, but the deviation from the experiment increases with time, which is probably resulted from the natural convection occurred in the aquifer, and its intensity is gradually strengthened.