Numerical Simulation On The Influence Of Premixed Flame Propagation In Pipe Caused By Initial Temperature

At present,the gas energy pipeline frequent accidents and serious consequences.In order to assist safety staff according to different ambient temperature conditions,formulate the corresponding measures of prevention and control the fire accident,in this paper,by using CFD software,the different conditions,the initial temperature effect of premixed flame propagation characteristics of the pipe.Rectangle pipe experimental model compared with previous experimental data is built up by using FLUENT software.After verify the accuracy of the model,the model is used to study the methane-air premixed gas and propane-air premixed gases flame propagation characteristics in the temperature range from 240 K to 320 K.And then use methane-air premixed gases for example to study the effects of initial temperature on premixed gas flame propagation characteristics for different initial pressure and different mass fraction in the temperature range from 240 K to 320 K.This paper finds that the initial temperature influence for different premixed gas flame propagation characteristics are the same.The flame speed rises when the initial temperature rises.The maximum pressure is reduced when the initial temperature rises.But at the same time the pressure rises speed inside the pipe rises with the initial temperature rises,in the Finger flame phase and Tulip flame phase.Simulation results show that under different mass fraction,the Finger flame speed and Tulip flame speed are increased when initial temperature increased.With the increase of mass fraction,the influence of initial temperature for pipe pressure rise speed is more and more small.Under the condition of different initial pressure,flame propagation speed rises when the initial temperature rises.When the initial pressure is bigger than 0.5 MPa,the maximal premixed flame temperature and Tulip flame average temperature don’t change with the initial temperature.Under the condition of different initial pressures,the maximum pressure in pipeline,and decreased with the increase of initial temperature.Can see how the advanced stage of flame rising velocity of the pipe inner pressure as the initial temperature rises,but under the condition of different pressure,Tulip flame stage of pipeline internal pressure rise speed change law is different,the initial stress in the range of 0.1 MPa to 0.5 MPa,the Tulip flame stage pipeline internal pressure rise rate increases with the increase of the initial temperature,initial pressure in the range of 0.5 MPa ~ 1 MPa,Tulip flame stage pipeline internal pressure rise rate and decreased with the increase of the initial temperature.