| In the 21st century,with the increasing demand for energy from the development of industrialization,people are ushering in a new period of high consumption of fossil energy.As a major fossil energy source,petroleum is widely used in military,industrial,transportation and other fields.These oil fuels are generally characterized by being flammable,explosive,low ignition point,and high combustion calorific value.Once a fire breaks out,it will cause huge casualties and property losses.Most fuel leak fires occur under windy conditions,and it is easy to form oil pool fires.Therefore,conducting experimental research on pool fire combustion under windy conditions is of great significance for understanding the characteristics of such fires.In this paper,a diesel pool fire combustion experiment platform was built in the Key Laboratory of Urban Underground Fire,using DC low-speed wind tunnel to provide stable wind field conditions for the experiment,and using a variety of measuring instruments to measure and record parameters under different working conditions value.According to the obtained experimental results,the theoretical research on the characteristics of pool fire combustion and plume characteristics under the action of horizontal wind were carried out.Specific research work includes:Focusing on the study of the combustion characteristics of pool fire under the action of horizontal wind,it mainly focuses on the four aspects of pool fire flame length,flame inclination angle,combustion rate and heat release rate.(1)Considering the disturbance effect of horizontal wind on the pool fire,the dimensionless parameter Hr is introduced to describe the geometric characteristics of the pool fire flame.The study found that when 0<Hr<0.34,horizontal wind promotes the flame length;when Hr>0.34,it inhibits.Through fitting the experimental data,the relationship between the average flame length and the average flame inclination angle of the diesel pool fire with respect to Hr under horizontal wind is obtained,and the relationship between the average flame inclination angle and the infinite wind speed u*is obtained.(2)A comparative analysis of the change law of the pool fire burning rate with time under the conditions of no wind and wind,and the exponential function relationship between m"windy/mstill" and ua/D was obtained through data fitting formula;(3)The calculation method of the heat release rate of the fire source is determined through comparative analysis,that is,the heat release rate of the fire source is calculated based on the combustion rate of the fuel,and the indexes of Qwindy1/Qwindy2 and ua1/ua2 are obtained through data fitting Function relationship.Focusing on the study of characteristic parameters of pond fire plume under the action of horizontal wind,it mainly includes four aspects of plume shape,plume mass flow rate,temperature and vertical flow rate.(1)According to the FDS simulation results,it was found that the cross-sectional shape of the pool fire plume gradually developed from approximately circular to kidney-shaped under the action of horizontal wind,and the research idea of turbulent jet in crossflow was introduced to analyze this change process.(2)Under the premise of understanding the morphological characteristics of the pool fire plume under the action of horizontal wind and the derivation process of the ideal plume model,new conditional assumptions are made and the prediction model of the characteristics parameters of the pool fire plume under the action of horizontal wind is established.(3)Compare the calculated value of the model with the experimental value,analyze the cause of the error,and verify the accuracy of the model. |
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