City Gas Pipeline Network System Optimization Design Method

Being a cleanness, highly active city gas, the use of the pipeline natural gas in city has been regarded as the great sign of modern civilized cities. However, because the city area enlarged constantly, the layout of city lagged relatively in collectivity, and that the layout time in gas's use is pressing. So it is very important to study the optimum design of city natural gas pipe network.In this paper, basing the characteristic of the optimum design of city natural gas pipe network and the theory of pipeline transportation, a multilevel optimization method has been adopted, which includes two parts: the topological optimization of pipe network and the structural parameter optimization of pipe network. First, the model about the topological optimization of pipe network is established to make network's investment expenses minimum, subsequently analyze it by graph theory, and make it out by improved Dijkstra.applying in text. Secondly, basing on the optimal topology, taking pipe's diameter, wall thick as variable and considering pipe waterpower, intension, and stability etc as constraint condition, the model about the structural parameter optimization of pipe network is established. All constraint conditions and object function are constructed nonrestraint function by using Combine Penalty Function Method. Thereinto, quadratic interpolation is uesed in undimensional search, and Powell arithmetic is used to solve unconstrained minimziation.The optimum design program of city natural gas pipe network is writed out by using Visual Basic 6.0, which is easy operation and high accuracy. Calculating examples using it, satisfactory results have been gained.