Study On Stability Of Multi-shaft Ventilation System In Gucheng Coal Mine

Stable and reliable ventilation system is the key to mine safety production.With the expansion of mining scale and extension of ventilation route,multi-shaft combined ventilation is more and more common,which brings about the stability problem of complex mine ventilation system.In this paper,theoretical analysis,field test and simulation methods are used to study the stability of ventilation system in Gucheng coal mine from two aspects: the influence of roadway wind resistance change on the stability of ventilation system and the influence of ventilation dynamic instability on the stability of ventilation system.(1)The underground parameter test of Gucheng coal mine was carried out,the intelligent ventilation simulation design system was established,the planning and design of the ventilation system of Gucheng coal mine was predicted and analyzed,and the relevant parameters of the ventilation system were determined.In order to solve the ventilation problems at the far end of the north second and fourth panes of Gucheng coal mine,after the Baodian inlet and return air shafts are put into operation,forecast and analyze the easy and difficult periods of ventilation.The simulation results show that the total resistance is expected to reach 4328 Pa in the difficult period of ventilation.It is predicted that the total resistance will exceed the limit during the difficult period of ventilation.The resistance reduction plan is redesigned.Finally,the method of reducing the air demand of the coal mining face is selected to reduce the resistance,and the ventilation is difficult after the resistance reduction.The total resistance of the period is 3896 Pa,the plan is feasible.(2)The "two in and two back" and "three in and three back" diagonal connection ventilation network models were established respectively to study the influence of roadway wind resistance change on ventilation system stability.By changing the equivalent wind resistance value of single edge branch,the paper qualitatively analyzes the influence law of the air volume of the diagonal connection air way in zoning.The analysis results show that the influence degree of the change of the air resistance of different edge branches on the stability of the diagonal connection air way in zoning is different,and summarizes the control measures to improve the stability of ventilation system.Through the sensitivity analysis method,the sensitivity of zoned diagonal connection air way is quantitatively analyzed,and the positive and negative correlation between zoned diagonal connection air way and its edge branches and the edge branches that have significant influence on the air volume of zoned diagonal connection air way are obtained.The stability of mine ventilation system can be improved by improving the control of highly sensitive edge branches.(3)The dynamic instability of ventilation is analyzed and the mutual interference between main fans is analyzed,the results show that there is no mutual interference between main fans in Gucheng coal mine.Aiming at the problem that the instability of ventilation power may cause the failure of ventilation power and thus the instability of ventilation system.The ventilation system after power failure of main fan in Taoyuan was predicted.According to the simulation results,Taoyuan’s return air shaft becomes an intake air shaft due to the effect of natural wind pressure after the failure of ventilation power,and there are some problems in the ventilation system,such as breeze roadway and zonal diagonal connection air way with reverse airflow.By changing the airflow volume of the air door,the airflow volume of the breeze roadway is increased,and the overall stability of the ventilation system is improved.There are 33 figures,32 tables and 66 references in this paper.