Optimization Study on Double Gas Drainage System of Low Permeability Thick Seam

With the coal mining depth and intensity increased,previous one set gas drainage system in major mines could not meet the mining and excavation and the mine safety production requirements.And the previous system with the high and low negative pressure gas drainage(pre-drainage and goaf drainage) would cause the high and low content gas mixed and would not be favorable to the gas utilization.Based on the circumstances,taking Yuwu Mine as a study object,an optimization was conducted on the available one set gas drainage system of the West Ventilation Shaft fixed at the surface ground.The service scope of the gas drainage system was reduced and was only responsible for the gas drainages in South No.1 and South No.2 Mining Blocks.A new gas drainage system was established and the two pipelines were applied to build high and low negative pressure gas drainage systems individually and to realize the separated source drainage of the high and low content gas in the whole mine and the gas control of each block.The results showed that the technical measures could effectively improve the gas drainage rate and improve the gas utilization rate.The high content gas could be put in the pipeline network and the low content gas could be utilized for the power generation.Meanwhile,the gas content over limit and gas outburst problems occurred in the mine excavation and mining face in high gas and low permeability seam were effectively solved.