Study On The Dispersion And Migration Process Of Hazardous Chemical Materials Leakage

Hazardous chemicals,one of the most used raw material for industrial production,are considered as a vital part of the national economy.Contacted with the temperature and pressure in atmosphere environment,liquid or liquefied chemicals would be transformed into dense gas,which may cause injuries and death to human.Therefore,the release of hazardous chemicals have been the focus of research on chemical safety.In the process of hazardous chemical leakage accidents,the dispersion of gaseous poisons in the atmospheric environment behaves as called dense gas dispersion,which makes a lager the lateral influence range,and more intense short-term damage,hence,leading to severe secondary harm.The research progress in the field of heavy gas is discussed in this paper.Based on the shortages of current research,a large-scale field experiment research method is proposed,and the organization,design and operation of a series of release experiments are presented and analyzed in this paper.This paper constructs the process of selecting and constructing release equipment,including concentration transducer,environmental data transducer and data transmission network in the release experiment.The anhydrous ammonia and Freon R134a are selected as experimental chemicals,and the continuous leakage and instant leakage experiments are reported.Experiments simulating two different kinds of dense gas formation process is conducted.Under different meteorological conditions,various sets of experiments were established to maintain similar release conditions.Through the data collection of 30 sets of sensors in the experimental area,the entire dispersion process of dangerous chemicals is mathematically described,and recorded.For the anhydrous ammonia release experiment,the relationship between ammonia concentration and release time,dispersion distance at different detection sites in the experimental area is compared and analyzed.It is found that about one minute after the release,the ammonia concentration near the release point reaches a peak,and for the long distance,the concentration reaches a peak after 5 minutes;at the same mast,the average ammonia concentration detected at 2 m height is 25.62%of the concentration detected at 1 m height.A phenomenon is discussed that the gas release,migration,and dispersion processes could reduce the ambient temperature.The distance from the release point in the axial direction from 36 meters to 60 meters exceeds the dangerous concentration of ammonia(500 ppm)of ammonia.According to the results from Freon R134a release experiment,the relationship between R134a concentration and release time,dispersion distance and ground height at different sites is compared and analyzed.The duration of the release process and the high concentration region maintenance time after the release are analyzed.The appearance of multiple peaks in the concentration data is analyzed,and the maximum concentration detected at different heights of the same position are compared,and the similarities and differences of the concentration fluctuation law are discussed.For the proposed sets of Freon R134a release experiments,the maximum concentration data obtained are compared and analyzed.