Study Of Scale Effect On Gas Explosion

Researches on law of gas explosion has been the key to study safe accidents in coal mines for the reason that gas explosion is one of the most serious accident during the producing process.Most of the current studies toward explosive characteristics are done on experimental platform for the reason that gas explosion has a significant destructiveness.A lot of gas explosion conclusions were taken in different sizes and forms on experimental platforms by many researchers at home and abroad according to their experimental schemes.On the base of gas explosion's law studies on Liaoning Technical University's vessel-pipe platform and others researchers' experimental data,this thesis synthetically analyzes the explosive characteristics of pipe and vessel-pipe platform in different sizes.The scale effect and the effect of support condition toward gas explosion's characteristics were studied by the use of CFD technique.It shows that there is a similar propagation tendency in pipe system with different length and diameter.A obvious scale effect occurs in the velocity of flame propagation during the gas explosion process.A larger scale flame propagation velocity occurs in a smaller diameter which is larger than critical resistance diameter.As the size of scale increases,the flame propagation velocity declines.The propagation tendency of explosion pressure is that it hits its highest value in a short time and then declines.There is a huge difference between explosion pressure among different gas concentrations in vessel-pipe system.The difference is that the rising rate of explosion pressure increases along with growing gas concentration.Through numerical simulation,as the section size of pipeline increases,it is found that the time flame surface needs to fill with the pipeline is increasing;The concave effect of flame surface in the end of the pipeline is more obvious;The average temperature in pipeline with a large section size is higher than smaller one while the flame surface reaches the same position.The explosion pressure in support pipeline which has oscillation in it is higher than none;The maximum rate of pressure rise in pipeline with a larger support size is bigger than the one with a small one.The average temperature in a large section size pipeline declines while the flame surface reaches the same position.