Research On Natural Gas Leakage And Diffusion Characteristics Under Complex Topography Based On Gaussian Plume Diffusion Model

With natural gas has been coming into thousands of homes,it is not uncommon for pipelines to be built directly near residential areas or public facilities,where tend to be crowded and densely populated.Under such a background in the event of serious leakage accident cause fire and explosion,even will lead to serious consequences,including numerous casualties and incalculable damage to property and so on.The mechanism of gas diffusion is complex and changeable.Any model has its own limitations and scope of application,and accurate prediction is quite difficult.Gaussian plume model belongs to the ideal model,greatly simplifies the turbulent and complex change of weather,not considering the Angle of leakage after the occurrence of gas injection and spread around the ups and downs of terrain changes.Considering the possible leakage conditions of natural gas pipeline in the actual situation and the important factors that affect its jet height,diffusion distance and concentration distribution.Three modifications were made to the model.By wind tunnel simulation test results verify the feasibility of the numerical simulation,through the use of Fluent software to carry on the numerical simulation,the results and improvement after the misty rain Gaussian diffusion model of rapid calculation results contrast each other,determine the results of the improved formula is accurate,effective and has better universality.Finally based on natural gas pipeline leakage at different angles,different wind speed and different obstacles exist many cases of diffusion occurs in the numerical simulation,and put forward a new fast calculation formula of the improved.The improved Gaussian plume model obviously improved its calculation results and was closer to the numerical simulation results.Compared with the classical Gaussian plume diffusion model,the error value was reduced by 12.6%.When there is an obstacle,the size of the obstacle is converted to ground roughness,so that the classical formula can be improved and improved,and the calculation result is more in line with the actual engineering requirements.Therefore,the improved Gaussian plume model has a certain practical value,which is more reliable and effective in predicting the concentration distribution of natural gas leakage.And can be fast calculation in complex terrain,rapid prediction,namely through theoretical study,and some deficiencies existing in classic Gaussian model,the further improvement for the fast calculation model of generality.