Experimental and numerical research of backfill cooling based on similarity theory

Based on the similarity theory, this paper conducts a dimensionless analysis of air flow and selects Archimedes number as the similarity criterion number in order to study the cooling effect of mine cold storage backfill under ventilation environment. The similarity experimental platform has been built through collecting actual stope parameters and determining the geometric and velocity scales. The influence of different backfill cooling methods and air supply conditions on the temperature distribution of stope has been studied both by similarity experiment and CFD numerical simulation. Through model verification, it is proved that Archimedes number is suitable as the similarity simulation criterion number in this research and the similarity method is feasible to predict the parameters in prototype. The results show that ventilation alone often fails to meet the specified cooling requirements in deep mine, and cold storage backfill is an effective method to control the temperature in stopes. Compared with the upward backfill method, the downward backfill method is superior in terms of cooling temperature and cooling duration. Because the position of the air supply outlet is close to the top of the stope, the ventilation has a great influence on the cooling effect of the downward backfill, and the excessive wind flow reduces the cooling effect. Furthermore, ventilation accelerates air convection, which makes the flow field in the stope unstable, and leads to horizontal temperature difference in logistic distribution.