Experimental and numerical investigations of heat transfer and phase change characteristics of cemented paste backfill with PCM

Abstract

A new cooling method with adding phase change material (PCM) to cemented paste backfill (CPB) for deep mine cooling has been proposed. The heat transfer and phase change characteristics of the new CPB have great influence on the cooling effect of deep mine. A three-dimensional transient heat transfer of the CPB with phase change and internal heat resource was investigated through numerical simulations and experimental tests. The results showed that the numerical model based on the enthalpy method model, the porous medium model and the hydration heat model can reveal the heat transfer of CPB with PCM accurately. In the cold release process, there are evident characteristics of stages in time and special distributions in space. As initial liquid fraction is the key factor of cold quantity, its influencing law on heat transfer has been investigated. With decreasing initial liquid fraction, the melting time would be prolonged, and the cold releasing time could be prolonged consequently. This study is significant for improving the understanding of the heat transfer mechanism of the new PCM backfill and is helpful to the design of the deep mine cooling by the cold load and storage (CLS) functional CPB.