Network Optimization Of Gas Gathering And Transportation System In Complicated Region

Gas gathering and transportation system is multi-level network structure,and the cost of construction is high,which accounts for 60%-70% of the total ground project investment.Topology optimization of gas gathering and transportation system is an important technical measure to reduce the investment.In the past,the optimal design usually adopts the method of grading optimization,ignoring the topography fluctuation in the calculation process,simplifying the obstacle area to planar convex polygon.The result is quite different from the actual project.Aiming at the problems in the topology optimization of gathering and transportation system,this paper takes the least cost of pipeline network as the objective function,constrains the affiliation,handling capacity and spatial location of different levels as constraints and establishes a multi-level star-shaped gathering and transportation network overall optimization model.Meanwhile,the factors of three-dimensional terrain and obstacles are introduced in the model,provides a highly efficient and accurate method for pipe network topology optimization in complex areas.Using the Goody GIS to collect the data of the target area,establishing the digital elevation model,and constructing the real ground surface of the area where the gas field is located by different interpolation methods,using the convex polygons and the concave polygons to represent the obstacles,respectively establishing the planar obstacles and the three-dimensional obstacles model.The three-dimensional topography and obstacles combined with the multi-level star-shaped network to establish the overall optimization model.The model contains both discrete and continuous variables,and the constraints are nonlinear.It involves discrete topological optimization and nonlinear parameter optimization,which is a large mixed optimization design problem.The traditional optimization algorithms can not solve the problem.In this paper,we use the swarm intelligence technique which combines the ant colony algorithm and the particle swarm algorithm to solve the overall optimization model of multi-level star-shaped gathering and transportation network considering the three-dimensional topography and obstacles.This method does not need the properties of continuous,differentiable functions of optimization function,and has the advantages of global search ability and high efficiency.According to the research results,the optimization software of gas field network in complex gas field was compiled by Matlab,which provided guidance for the planning and design of gas field engineering.