Study on temperature drop and cooling effect of cold wall for backfill body with embedded cold fluid tube

In recent years, the thermal damage in deep mine has become an urgent problem to be solved. A three-dimensional heat transfer model of backfill body with embedded cold fluid tube was established, the influ-ence of tube spacing, the inlet temperature and velocity of cold fluid and the thermal conductivity of backfill body on the temperature distribution and cooling capacity of cold wall were analyzed. The results show the cooling capacity at steady deceases from 11.72 kW to 4.16 kW when tube spacing increases from 0.5 m to 1.5 m, the cooling capacity increases by 2.06 kW when inlet temperature decreases by 4 degrees C. When thermal conductivity increases from 0.5 W/(m center dot degrees C) to 2.0 W/(m center dot degrees C) in 0.5 W/(m center dot degrees C) increment, the increment of cooling capacity is about 3.22 kW, 2.17 kW and 1.52 kW successively on average in 20 days-60 days. Comparison shows the wall temperature of backfill body obviously decreases and quickly forms the cold wall as cold fluid passing through tube, the cold will be released rapidly from cold wall to airflow. The research can provide the theoretical basis for the application of radiation cooling of backfill body in the control of mine thermal damage.