Influence Of Turbulence On Explosion Limits And Flame Propagation Process Of Combustible Gas(Vapor)

With the widespread use of combustible gas(vapor),it is likely to occur combustion and explosion accidents in its actual production,storage and transportation and the process of its use,which have become one of the main forms of catastrophic accidents.Therefore,how to prevent and control explosive accidents caused by combustible gas(vapor)effectively is still a new subject,which needs to be solved in the civilian industry and military production fields.At present,domestic and foreign scholars mainly study combustible gas(vapor)explosion characteristics at the macroscopic and static state.In the actual production and life the combustion and explosion accidents often happen in the turbulent flow field.Thus,it has great theoretical value and practical value to study the influence of turbulence on the explosion limit and flame propagation process of combustible gas(vapor).In this paper,the influence of turbulence on the explosion limit and flame propagation process of combustible gas(vapor)were studied by the means of FRTA explosion limit tester and high temperature photometer.The experimental results were analyzed,compared and summarized qualitatively and quantitatively according to the relevant combustion and explosion theory.Research indicates:(1)Combustible gas(vapor)explosion range narrow at the turbulent flow state compared to the macroscopic and static state.With the increase of the relative molecular mass of combustible gas,the influence of turbulence on the explosion limit range increases.The effect of turbulence on the explosion range of flammable liquid(vapor)is more pronounce than the explosion range of combustible gas.The explosion range of combustible gas(vapor)narrow with the increase of turbulence intensity,and the increase of turbulence intensity decreases the risk of fire accidents to a certain extent.(2)Turbulence disturbances can cause the flame shape to change,that is,the front of flame produce wrinkles and the boundary is not clear.The greater the turbulence intensity,the more obviously the flame front wrinkles and the more blurred the flame boundary.Turbulence increases the speed of flame propagation rate significantly.(6)In the actual production and daily life,with the increase of turbulence intensity the combustible gas(vapor)explosion limit range narrows.But in the high turbulence intensity the flame propagation speed increase.Therefore,it should be considered synthetically and choose a safety factor reasonably.To sum up,the research results enrich the combustion and explosion theory of combustible gas(vapor)at turbulent flow state,which is very important to evaluate the risk of explosion of common combustible gas(vapor)and prevent the occurrence of explosion.