Study On The Influence Of Inert Gas On The Explosion Limits Of C₂H₆/O₂ Mixtures Under Complex Working Conditions

At present,with the advancement of science and technology,more chemical process involves the reaction and operation of flammable gases under complex conditions such as elevated temperatures and pressures.Thus,more explosion limit data and variation rules of flammable gas at elevated temperatures and pressures are required.But due to the complex initial conditions of the experiment,there are few studies on this aspect.Based on this background,the variations of explosion limits of the ethane/oxygen mixtures at elevated initial temperatures and pressures were studied.The inhibition of inert gases on explosion limits of ethane/oxygen mixtures,and how the elevated initial temperatures and pressures affect the inhibition effect were also analyzed.The main work and conclusions are as follows:?1?According to the relevant standards,an experimental platform was set up to measure the explosion characteristic parameters of flammable gas under complex conditions.A mother-child flange and ceramic core electrodes were designed to solve the sealing problem at elevated temperatures and pressures.?2?The explosion limits of the ethane/oxygen mixtures were measured at initial conditions of 0.5².6 MPa and 20²70°C.It can be concluded that the explosion limits of the ethane in oxygen increase with the increasing initial temperatures and pressures.When at the elevated initial pressures,the upper explosion limits of ethane in oxygen gradually increase with the increasing initial temperatures.When at the elevated initial temperatures,the upper explosion limits of ethane in oxygen gradually decrease with the increasing initial temperatures.And the quantitative relationships related to the explosion limits of ethane in oxygen and the elevated initial temperatures and pressures were obtained:UEL=z₀+BT^C+DP^E+FT^C P^E?0.5 MPa<P<2.6 MPa,20?<T<270??LEL=z₀+Aexp?-T/B?exp?-P/C??0.5 MPa<P<2.6 MPa,20?<T<270???3?The explosion limits of the ethane in oxygen with inert gases?nitrogen and carbon dioxide?concentrations of 0,20%,40%,60%,and 80%were measured under four initial conditions:ambient temperature and pressure,elevated temperature and ambient pressure,ambient temperature and elevated pressure,and elevated temperature and pressure.The experiments results show that the explosion limits of the ethane in oxygen gradually shrink with the increasing concentration of inert gases.The inhibition effect of inert gases was redefined:F_g=??UEL₀-UEL_g?/UEL₀?×100%The inhibition of the two inert gases is enhanced by elevated initial temperature or initial pressure.However,the coupling effect of elevated initial temperatures and the initial pressures on the inhibition of the two inert gases is less than the effect of a single factor.It is found that the inhibition effect of carbon dioxide is higher than that of nitrogen through comparison.At the same time,the ternary composition maps based on the experimental data were drawn to meet the industrial process applications.