Study On The Diffusion Of The Instantaneous Leakage Of Natural Gas And Its Blasting Area

Natural gas is a clean and efficient energy. It is an effective way to alleviate the increasingly prominent chemical energy; and it is widely used in various industries. There are many large storage tanks explosion accidents caused by combustible gas leakage diffusion, which would cause huge economic losses and casualties. Although there are has a lot of research and report about the combustible gas in the tank leakage and explosion, the existing studies or research on the gas diffusion mostly for continuous discharge, however, the study is less about instantaneous leakage. Or more attention to factors media pressure, weather conditions on the diffusion, paid little attention to the ground roughness and atmospheric stability of influence of parameters on the leakage. For research in the field of natural gas leaks after instantaneous combustion area is almost empty, existing research does not lead to the proliferation of instantaneous leak caused by blasting and then such incidents mode provides more effective and clear technical guidance.Based on this, the use of Matlab software and use a gas tank as an example, the regulation of diffusion of gas instantaneous leakage numerical simulation analysis for the analysis and prediction of natural gas leak diffusion distance, diffusion and diffusion area of the flare provides the basis for effective control of accidents and reduce the consequences of accidents. First, determine suitable for light gas Gauss puff model; then, based on the Gauss puff model simulation analysis, mapping and other mass concentration curve and flare blasting regional gas leak instantaneous leakage diffusion; Third, analyze leakage, atmospheric stability, surface roughness and other factors affecting the diffusion of natural gas and flare blasting area were determined under different conditions; Finally, based on the results of the numerical simulation analysis, emergency evacuation and rescue measures after the natural gas leakage. The main contents and conclusions are as follows.(1) Establish a gas tank leakage diffusion numerical simulation model. After validation, we take a more in-depth discussion about instantaneous gas leakage.(2) Study of the regulation about flammable gas instantaneous leakage, proposed the use of two parameters that cross-wind and down-wind distance to assess the scope of flammable gas cloud size quantitatively. The results showed that, when the leakage Q=1x109mg, surface roughness Zo=1m, wind speed u=5m/s, the gas leakage diffusion concentration distribution symmetrical in the horizontal direction, and the diffusion distance is of1576m and the diffusion area is472595m2.(3) Take full account of the different amount of leakage, surface roughness and atmospheric stability effects on the diffusion of natural gas leakage; determine its diffusion distance and diffusion area. The results showed that:gas diffusion distance and area increases with the increase of the amount of leakage; more stable the atmosphere is, the greater the diffusion distance and diffusion area; diffusion distance and diffusion area increasing with surface roughness decreases.(4) Analysis of the different parameters, determine the scope of the flare combustion area. The results show that it has the same regulation with the diffusion.