Numerical Simulation For Premixed Gas Flame Propagation Process In Bifurcation Pipeline

Combustible gas explosion occurs frequently in the industry and roadway,which can cause a large number of casualties and property losses.In the industry and roadway,what we often see is a straight pipeline that is constant section,but the bifurcation pipeline also can be seen everywhere.In the process of coal mining,the roadway is also a "pipeline" and the layout is very complex.Bifurcation pipeline is inevitable.In addition,when collecting the underground roadway gas and transporting combustible gas in the industry,we will also see the situation of bifurcation pipeline.So we can see the significance of study the bifurcation pipeline.The study of the gas explosion flame propagation at the bifurcation pipeline has important practical significance and scientific meritFirstly,depending on the experimental conditions,FLUENT software is used to simulate the premixed flame propagation process for the straight pipeline.The accuracy and validity of the choice of model and parameter setting in numerical simulation are verified through the experimental data and photographs.This provides a new method to research the contingency question.Then,the validated model and parameters are used to simulate the premixed flame propagation process for 90°?135° and 45° bifurcation pipeline.The main research contents are the change of flame shape before the bifurcation and the turbulence that the bifurcation produces exercises influence on the flame temperature,the pressure in the pipeline and the flame propagation velocity.At the straight pipeline,tulip-shaped flame forms twice.The form of tulip-shaped flame has a direct relationship with pressure wave that the right pipeline reflects.If the pipeline is long enough,tulip-shaped flame can be repeated to form.When the flame propagates the bifurcation,due to obstacle induction and area increases suddenly,turbulence will increase.Thereby combustion speed increases,which leads to that heat release rate increases,resulting that the flame temperature,the pressure and flame propagation speed of the branch pipeline increase.So the extent of the damage of branch pipeline increases.Finally,comparing with the bifurcation of three bifurcation angle at the impact on premixed flame propagation,this article gave a specific quantitative analysis from the flame temperature,the pressure inside the pipe and flame propagation speed.The result show thatthe 90° bifurcation pipeline is more severe than the 135 ° bifurcation pipe at the extent of the damage after the bifurcation when an explosion occurs.The 45° bifurcation pipeline is smaller extent of the damage.In addition,you can also get the conclusion that the extent of damage inside the branch pipe T is more obvious than inside the branch pipe R.So we should decrease or avoid the situation of bifurcation pipe in industry or when we design the mine,especially 90°pipe bifurcation situation,which has important guiding significance for practice.