Study On Optimization Of Pipeline Transport Process In Jingxi Third Line

Natural gas is a clean and high quality energy,increase the proportion of natural gas in primary energy,to optimize the energy structure in our country,relieve the strain on China’s demand for energy and environmental pressure has important significance.In recent years,with the increase of test gas development scale and the use of scale,natural gas pipeline construction and rapid development of increasingly large and complex natural gas pipeline system,pipeline construction investment and operation cost increases accordingly,natural gas pipeline system optimization design and operation research,to increase economic benefits pipeline system and guarantee safe operation of the pipeline system has important significance.This paper discusses the research status of optimization design and dynamic numerical simulation of natural gas pipeline system at home and abroad.In jingxi three line natural gas pipeline system optimization design of specific problems,set up in gas transmission pipeline system,the objective function is minimum total cost,technical and economic model,the constraint conditions including boundary conditions,pipeline strength and hydraulics constraints,optimization variables as pipe diameter,compressor pressure ratio and compressor outbound pressure and wall thickness.By using the genetic algorithm was used to solve mathematical model analysis,through case calculation and scheme comparison,the model more reasonably reflect the pipe diameter,gas pressure and wall thickness influence on total cost,and the actual design data error is small,the reliability of the model was verified.Due to the user in the operation of the natural gas pipeline in gas along with the change of production load,pipe/points of feeder switched on or off,partly due to the start-stop of compressor station,cause system in transient conditions.According to the characteristics of the unsteady condition of gas transmission pipeline system,based on fluid continuity equation,motion equation and energy equation,respectively established the unsteady fast transient process and slow transient mathematical model,using the characteristic method and implicit central difference method,respectively,for fast transient and slow to solve the transient model,and analyzes the characteristic method and implicit central difference method to solve partial differential equations of mathematical method and processing method of boundary condition.Respectively of the proposed model was applied to gas pipeline system of fast transient condition and slow transient conditions case,the simulation results with the literature values described the pressure at the ends of pipes have the same change trend,can better reflect the unstable running condition of the gas transmission pipeline,to prove the reliability of the model,which can be used to instruct the practical operation of gas pipeline.