Research On Methane Explosionin Horizontal Pipe With Complex Shape Obstacles

Because many methane explosion accidents occurred in coal mines, more and moreresearches are conducted on the hazard of methane explosion, and there is a growing focus onthe influence of obstacles on the propagation process of methane explosion. However, due tothe varieties of obstacles in mines that may cause influence on this process, present researchesare mostly remain on small-size pipeline and obstacles with simple shape and structure. It isrecognized that the research of the influence of complex obstacles on gas explosion hassignificant social and economical meanings.Using horizontal pipe gas-dust explosion experimental appliance, this research focusedon the influence, which are imposed by factors as number of holes, blocking rate, amount ofpieces, spacing, location and space structure etc., on 10%(volume) content of methane-airexplosion process, and conduct a contrast research. Under the experimental condition, theresults are as follows:1. Obstacle has obvious influence on mixed methane-air explosion process in thepipeline, placed appropriate obstacles can significantly enhance the explosion pressure andflame propagation velocity;2. The amount of obstacles, blocking rate and space structure impose distinguishedincentive effect on explosion process in the pipeline. As the growing amount of obstacles, themaximum explosion pressure and flame propagation velocity of the mixed air growsaccordingly and when the amount reaches 7, the speed-up effect reaches certain limit; with therising blocking rate of the obstacles, the maximum explosion pressure and flame propagationvelocity of the mixed air increases accordingly and when reaches certain extent, Throttlingeffect became the dominant one. When the blocking rate is small, the incentive effect onexplosion process is more obvious with more complex space structure, with larger blockingrate, the throttling effect become more significant when the space structure is complex. 3. The spacing and location of obstacles imposed little influence on mixed-air explosionprocess, as the spacing grows, the process are basically the same, the maximum explosionpressure and flame propagation velocity do not change significantly, while with larger andlarger spacing, it has the more continuous flame acceleration; Change of the location ofobstacles changes the explosion process little, more distant from the ignition end, morecontinuous flame acceleration.