Study On The Law Of Multicomponent Nature Gas's Leakage And Diffusion In High Pressure Leaking Pipeline

Through the system analysis of the different gas leakage, the diffusion after gas leakageand the consequences are closely related to leakage mode, the gas characteristic, diffusionparameters and environmental parameters. Analyzing the above factors and determining theshape and size of the grid of the simulated space, then selecting the FLUENT model, andsetting the boundary conditions.Base on the analysis of numerica l simulation results, it conclusions:(1) The law of stress distribution: gas pressure is bala nced with air in the sma ll range ofdirection of X and Y directions. Gas only containing methane pressure is bala nced with the airmore easily tha n gas containing hydrogen is. Pressure decreases from the leak hole to theatmospheric with the aperture of the radia l dista nce increasing. Pressure isoline is to rightunder wind's speed 5 m/s.(2) The law of velocity distribution: the ma ximum gas velocity is on the axis of the samesection, the farther from the axis, the velocity is lower; The more sulfureted hydrogen naturalgas contains, the jet height is lower to decrease to the same velocity; The bigger leakage holearea is, the gas velocity is higher at the same location; The velocity isoline is not immed iatelyoccur leak hole after the gas lea ves, but after deflecting out long dista nce, the longer the radia ldownward direction dista nce is, the more obvious is the tilt; radia l velocity as the pressureleak hole increases the same dista nce.(3) The law of concentration distribution: gas only containing methane and containingmethane and hydrogen sulfide are different kinds of gas, for the safety region distribution inthe whole simulation space the former is more symmetrica l, the former is on the both bottomsides and in the proportion of area, safety space increases with the hydrogen sulfide concentration decreasing; Under the condition that other parameters are same, the biggerleakage hole area is, the gas density is higher at the same location; When the wind is in thespace, the safety area in simulation space deflects to right, the relative dangerous rangeincreases; the greater system pressure is, the bigger is the effective area of gas diffusion, thebigger is risk factors of the system.By analyzing the simulation results it obtains the diffusion law of souroil gas of highpressurepipeline after leakage, and it provides the theory basis for decision-making ofemergency rescue.