Study On Propagation Characteristics Of Gas Explosion Shock Wave In Gas Tank Of Integrated Pipe Gallery

Urban underground comprehensive pipe gallery is a new type of pipeline construction mode,which contains gas tank,power tank,sewage tank and other compartments.The high temperature and high pressure shock wave generated by the gas leakage explosion of the gas tank in the pipe gallery will cause serious damage to the adjacent cabins and ground structures in the underground composite pipe gallery,which will bring great economic losses and negative social influence.Therefore,it is of great practical significance and practical value to study the propagation characteristics of gas explosion shock wave in gas tank of pipe gallery for the construction and safe operation of comprehensive pipe gallery.This paper takes the gas tank of integrated pipeline gallery as the research object.Firstly,the propagation of blast wave is analyzed theoretically.Secondly,pipeline explosion test is carried out.Finally,the gas tank model of pipeline gallery is established,and Fluent software is used for numerical simulation.The main conclusions are as follows:Small size pipeline explosion experiments with different methane concentrations were carried out to analyze the change of overpressure.The results show that the overpressure increases first and then decreases with the increase of time.When the methane concentration is 9.5%,the overpressure is the largest.Based on the experimental results and literature explosion test data of large size roadway,Fluent software was used for numerical simulation,and the validity of the numerical model was verified.The full-size model of gas tank in pipeline gallery is established and numerical simulation is carried out.The results show that the overpressure and airflow velocity fluctuate repeatedly with the increase of time.With the increase of distance,the peak value of overpressure increases first,then decreases and then increases,the peak value of flow rate increases first and then decreases,and the peak value of temperature increases first and then decreases and then remains relatively stable.Flame propagation length is about 2.5 times the length of gas accumulation.The effects of gas tank height,ventilation zone length,gas accumulation length and concentration on blast wave propagation in gas tank are analyzed.With the increase of gas tank height,the peak of flow rate and overpressure decrease,the peak of temperature decreases,and the flame propagation distance decreases.Extending the ventilation zone does not increase the maximum overpressure,and the length of the ventilation zone has little influence on the peak flow rate and temperature.The longer the gas accumulation length is,the greater the peak value of overpressure and flow velocity,and the higher the peak value of temperature.However,when the gas accumulation length exceeds a certain critical length,the influence of explosion overpressure,flow velocity and temperature on the accumulation length is less.When the concentration exceeds the optimal concentration 9.5%,the overpressure peak at the same location has little difference in velocity peak.The higher the concentration,the slower the temperature peak drops and the farther the flame spreads.The velocity peak and overpressure peak meet the first function relationship.Figure [54] table [13] reference [96]...