| Gas explosion occurs in the heading face,and the blast wave will destroy the damper,causing toxic and harmful airflow to pollute other working faces,and eventually causing the expansion of the disaster.Therefore,it is necessary to study the impact load and static characteristics of the damper in the process of explosion propagation,so as to provide theoretical support for the safety protection and design improvement of the damper.This paper takes the straight and branch air doors in the driving roadway as the research object,uses the fluid mechanics software Fluent,and combines the actual situation of the Yangchangwan coal mine of Ningmei Group to numerically simulate the gas explosion propagation in the driving face and analyze the different explosion conditions.The influence law of the impact load of the damper is analyzed,and the structure static analysis of the damper at the moment of the first peak of the impact load is carried out.The main research conclusions are as follows:In the process of gas explosion propagation in heading face,the impact load of straight roadway damper and branch damper has a peak value once under the action of front drive pressure wave,and a second peak value under the action of reflection shock wave.Increasing the gas accumulation range can significantly shorten the time taken for shock wave to reach the damper and increase the primary and secondary peak values of the damper impact load.Bend and fork in the branch can effectively reduce the intensity of shock wave and protect the damper to a certain extent.The ignition location is far away from the heading face,and the blast produces the damper shock wave and the working face shock wave which propagate backwards.The damper impact load has two peaks successively under the action of the two shock waves,and three peaks under the action of the reflection shock wave.As the ignition location is far away from the working face,the amount of gas bound by the blast wave in the direction of the damper decreases,and the amount of gas bound by the blast wave in the direction of the working face increases.The first peak of the damper impact load is advanced and then delayed,and the second peak of the damper impact load becomes the maximum of the load.Within the limit of the concentration of gas explosion,the impact load of the damper varies basically in different concentrations of gas explosion.When the gas concentration is 9.5%,the damper impact load reaches the maximum value in the shortest time.When the impact load of the damper reaches a peak,the equivalent stress distribution and deformation of the damper are basically the same as those of the branch damper,but the maximum equivalent stress and deformation of the damper are larger.The equivalent stress nephogram of the damper is symmetrically distributed,and the stress is mainly concentrated at the door edge and the center area,while the stress at the door corner and the transition area from the center area to the door edge is relatively small.The center area of the damper deforms seriously and attenuates to the door edge,showing regular elliptical distribution.When the shock wave acts on the damper,the damper breaks instantly but deforms less.At the first peak of the impact load of the air door,the equivalent stress distribution and deformation of the air door of the straight road and the branch road are basically the same,but the maximum equivalent stress and maximum deformation of the air door of the straight road are relatively large.The equivalent stress of the air door is symmetrically distributed,and the stress is mainly concentrated in the door edge and central area,and the stress in the transition area from the door corner and the central area to the door edge is relatively small.The center area of the air door is severely deformed and attenuates toward the door,which is distributed in a regular ellipse.When the shock wave acts on the damper,the damper is destroyed instantly but the deformation is small.35 pictures,6 tables,81 references. |
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