Research On Tracing The Source Of Dangerous Gas Near Field Leakage

Hazardous chemicals are widely used in production and life,among which gaseous or pressurized liquid is the more common form of existence.Once they leak,they will directly threaten the life and property safety of people around them,and also cause great damage to the environment,causing social panic and other problems.The precursor of leakage is often micro leakage or escape leakage,which is difficult to find and does not cause a direct impact,and is often ignored.Leakage traceability is an important prerequisite for the treatment of chemical leakage accidents.Rapid leakage traceability and accurate location of micro-leakage or escape leakage source in the shortest time are necessary means to prevent leakage.This paper first introduces the dispersion law of dangerous gases in the atmosphere after leakage,summarizes the research methods used to study the dispersion law,and the tracing method developed based on the dispersion law.The purpose of this study is to use reasonable research methods to study the general dispersion law of light gas and neutral gas in the near field when there is micro leakage or escape leakage,fill in the experimental observation required in the field of dangerous chemical safety,and then develop a model based on the law to provide a theoretical basis for tracing the source.In this paper,a full-scale experiment and wind tunnel simulation method were designed to study the near field dispersion of neutral gas ethylene under the influence of natural wind.A full-scale wind tunnel was built indoors to control the wind speed.Under the influence of the wind vector which is not strictly continuous but the wind speed and direction remain unchanged,the dispersion law of light ammonia gas after a slight leakage in the near field was studied.In the occurrence of near-field leakage,concentration will gather downwind of the leakage source.Continuous leakage can be regarded as continuous Dispersion of Gaussian smoke clusters,which move downwind along a monotonically increasing curve,then monotonically decreasing.When monotonically increasing,it presents an "S" shaped curve.Based on the law found,a near field dispersion model describing unsteady dispersion process is studied by means of curve data analysis and fitting.In order to keep the accuracy of single wind direction model in the environment where wind vector changes constantly,a sampling method for wind vector changes was studied to optimize the tracing process and reduce the tracing cost.The experimental data of ethylene leakage under the influence of natural wind were analyzed by this method,and the smoke masses under the influence of a certain wind vector were reproduced,which proved the feasibility of this sampling method to a certain extent.