Research On The Non-stop Switching Process Of The Mine Main Fan

The regular switching process of mine ventilation system will directly cause the whole mine ventilation system to stop ventilation in a short time,which will increase the threat of mine gas accumulation.In this regard,this paper puts forward the scheme of non-stop air switching of mine main fan,and carries out prediction analysis and verification on the flow situation,fan working state,valve bearing pressure and other aspects in the process of non-stop air switching by numerical simulation and experiment.The main contents include the introduction of on-off air switching technology,optimization of on-off air scheme,flow analysis of on-off air switching process and experimental verification of the actual effect of on-off air switching.Non-stop wind switching can fundamentally solve the problems of airflow turbulence and gas accumulation caused by underground wind shutdown during the switching process,and contribute to the safe operation of mining enterprises.This paper first analyzes the gas accumulation phenomenon when the wind is stopped in the mine through numerical simulation.The results show that: during the main ventilator switching process,the underground ventilation is interrupted,the air flow is reduced,and the gas accumulation is prone to cause local gas concentration exceeding the limit.Research and analysis of the air flow conditions and the working status of fans and valves under 10%,30%,and 50% switching conditions during the non-stop wind switching process,the results show that the gas flow rate will decrease to a certain extent during the switching process,from 324.463 kg /s was reduced to 265.786kg/s,and then gradually recovered as the switching process.The feasibility,reliability and safety of the system are verified by numerical experiments.After the air shaft of Pingshuo Jinggong No.3 Mine is reconstructed,the process of non-stop air switching is analyzed by field test.The experimental results show that the scheme can operate safely and stably,and solve the problem of air cutoff in the process of switching.