Experimental And Numerical Simulation Study On The Damage Characteristics Of Saturated Alkane Jet Fire

Once the compressed combustible gas leaks in the pipeline,the jet fire accident caused will be more destructive,which will have a serious impact on the surrounding environment and personnel within a certain range.In order to study the influence factors of jet fire hazard properties,this paper summarizes jet fire experiments and simulation work both at home and abroad,designs the experimental site of jet fire,studies the jet pressure,nozzle diameter and different chemical reaction mechanism of methane and ethane jet fire,and analyzes the influence degree and thermal radiation range of different working conditions on j et fire through numerical simulation.It is hoped to provide some reference for reducing the harm degree of jet fire and the harm of firefighters in the process of rescue.The main conclusions are as follows.（1）Experimental researches find that the flame height,maximum temperature and thermal radiation intensity of the two kinds of gas jet fires increase with the increasing jet pressure in the pressure range of 0.01MPa-0.20MPa.The maximum temperature increases gradually,but the increasing range decreases gradually.In 30mm-50mm caliber,the flame height,maximum temperature and thermal radiation intensity increase with the increasing nozzle diameter,in which the maximum temperature increases and the growth rate decreases.Therefore,with the increase of pressure and nozzle diameter,the danger range of jet fire becomes more and more serious.（2）In the experimental conditions,the thermal radiation intensity of methane and ethane exceeds 25k W/m² at a distance of 30cm from the flame,where the personnel exposed for 10s cause significant damage,and achieve the minimum ignition energy of wood combustion without flame radiation.（3）In this paper,the standard k-εturbulence model and the Eddy-Dissipation concept（EDC）combustion model with detailed chemical reaction mechanism are used to simulate the characteristics of the combustion reaction.The simulated temperature and thermal radiation values are the same as the experimental curves,with good agreement.（4）Three different chemical reaction mechanisms are used to simulate the methane jet fire,and the results show that the 41-step reaction mechanism can better predict the temperature and radiation field;the maximum value of CO₂ mass fraction generated by methane combustion is0.135,the maximum value of CO mass fraction is 0.033;the maximum value of CO₂ mass fraction generated by ethane combustion is 0.181.Finally,by analyzing and predicting the harm range of methane and ethane jet fire,the paper obtains the influence range of people,equipment and other targets around the jet fire,which provides a certain reference for emergency rescue work in relevant places where there is the harm of combustible compressed gas jet fire.