Performance experiment of dust removal and waste heat resources recovery of mine ventilation

Coal mining process will produce a huge amount of low temperature heat sources. It does help to achieve the purpose of environment protection and energy saving if the waste energy can be used legitimately. The waste heat recovery and purification system of mine ventilation was designed to recover sensible heat and remove the dust in the mine ventilation system by using multi-stage spray chamber. In this paper,the heat transfer efficiency and the dust re- moval efficiency at various stages were studied experimentally,and the influence factors were analyzed. The results show that after adopting two-stage spray chamber,the temperature of return water increases about 3. 4 ℃ ,and the total heat exchange efficiency is 82. 72% ,when all other parameters remain constant,namely the overall mass flow ratio of water to wind remains 0. 649 8,the single stage mass flow ratio of water to wind remains 0. 324 and environmental tem- perature is 17 ℃ . With the increase of air temperature and humidity,the heat transfer efficiency at all levels increases which is not obvious when the humidity exceeds 70% . The heat exchange efficiency decreases and the removal effi- ciency reduces with the increase of air velocity. The heat exchange efficiency reduces as the inlet water temperature of the spray chamber increases. When the air velocity is 1 m / s,the removal efficiency is 55% .