Numerical and experimental studies on the cooling performance of backfill containing phase change materials

Abstract

A novel method for deep mine cooling based on using backfill containing phase change materials (PCMs) was verified by numerical simulations and experiments. A laboratory-scale experimental system was designed to test the cooling process of backfill with ice particles as the PCM. Two boxes connected by a median clapboard were used to simulate the backfill and adjacent stope regions. A 3D numerical heat transfer model was developed in which the backfill region was modelled using an enthalpy method model and a porous medium model and the stope region was modelled using DTRM and a natural convection model. The numerical model was validated against experimental results and used to conduct a simulation study. The simulation results showed that the backfill containing the PCM produced a clear cooling effect on stope. A sensitivity analysis was performed to investigate the influence of the initial PCM liquid fraction, backfill slurry concentration, and filling strategy on the cooling performance. The analysis results showed that by decreasing the PCM initial liquid fraction enhanced the cooling performance, whereas the backfill slurry concentration had little effect on cooling performance over the recommended concentration range. Furthermore, the filling strategy was optimized.