Research On The Selection Of Routes And Pipe Diameters For The Layout Of Natural Gas Network

Recently, the voice of strengthening the environmental protection has accelerated the reform of the application technology of new energy sources. Natural gas gradually became an important source of energy in life for its advantages, such as cleanness, efficiency and convenience; however, many cities are faced with the layout of natural gas pipe network problems. The natural gas pipe network optimization design has gradually become one of the hot issues nowadays.As for the huge investment of natural gas pipeline network, reasonable pipe network optimization can save the costs, shorten the construction period, and bring huge economic benefits. This paper mainly discusses the selections problems of routes and pipe diameter for the layout of the natural gas pipe network.In this paper, we established a general mathematical model according to natural gas pipe network theory and actual demand, Then, we studied the problems on two sides-the selected route and the choice diameter, further discussed three problems- the simple network design, the given demand for network design and the diameter selection for network established; and designed algorithm and verified its feasibility and effectiveness.We applied the quasi ant colony optimization algorithm to resolve simple pipe network question. The algorithm incorporates traditional ant colony algorithm's characteristics, such as the pheromone, increasing evaporation and so on; it also establishes a new idea as "fix margin, then seek point", making up for the shortcomings of the traditional ant colony algorithm that can not produce banding branch of the tree of the network structure.For the given demand for network design, we applied an improved genetic algorithm which is based on the policy of map, and then designed the fitness function, a single parent of transposition operator, reversed order operator and recomposing operator, also used a discrimination matrix for feasible solution.About the third problem, we analyzed the relation between the fluxes and the diameters which are variables in the model; and then divided the variables into two parts: continuous variables and discrete variables. We used the complex algorithm to get the value of the continuous variables, and judged whether is a viable by the relationship between the flux and the diameters, and then achieved optimal solution by some principles, as reverberation, expansion and compression methods.