| The advantages of natural gas, compared to coal and oil, have no waste water, no residue, safer, higher calorific value and cleaner. Therefore, natural gas is welcomed in the era of the LCE(low-carbon economy). Pipeline as the main mode of transportation of natural gas, forwards long-distance, large-diameter, high pressure, and cyberization, and gradually becomes a large-scale and complex gas supply system. As natural gas system becomes more and more huge and complex,it increases the difficulty of understanding and mastering the operation rules accurately, limiting demonstrate and present a reasonable optimal operation scheme, and letting the analysis and process capacity of its emergency operating conditions becomes difficult. Moreover, it seriously impediment to the natural gas pipeline network system in rational planning and designing, safely dispatching management and accurate operating control. Therefore, in order to study the complexity of large natural gas pipeline system accurately, gas pipeline network simulation technology is emerging. As the supporting skill which helps to make decisions of the natural gas network, it reveals the flow process, heat and water distribution under the different designing, managing and operating scheme. Apart from this, it also describes the changing trend and process of water and heat under different manipulations, changes and accident conditions. Consequently, this paper has a great significance for the optimal design, effective management, reasonable dispatch and reliable operation.This paper investigates a large number of domestic and foreign literatures. It keeps in steps with the research of dynamic simulation in the natural gas pipeline network and analyses the dynamics simulation of natural gas pipeline network.At first, other papers ignore questions such as convection item, inertia item and neutral item in the process of present natural gas pipeline dynamic simulation. So, this paper constructs the natural gas pipeline dynamic simulation math model using the equation for all kinds of fluid such as continuity equation, momentum equation, energy equation combined the enthalpy equation and state equation of real gas, which it is suitable for almost all circumstances.Secondly, this paper lays a foundation for pipe network dynamic simulation using BWRS gas state equation, drawing up the gas physical properties bags,adopting parabola method iterative solution which increases the calculate speed and precision of gas state parameters significantly. Besides, this paper uses Colebrook formula which has a wide range of application and higher precision. In addition, this paper uses secant method to calculate friction coefficient. Then, the pipe flow is linked with friction coefficient that can decrease the friction coefficient errors which are produced by fixed value input.Thirdly, introducing RIEMANN INVARIANT n and m, differential operator S, M and N, the paper constructs dynamic simulation state space model in method of characteristics. Then, through the inverse step method and the linear interpolation method, the paper combines original conditions and boundary conditions to realize the solution easily.Finally, through C++ Builder XE6.0 platform, the paper uses C++ language to compile the natural gas pipeline network dynamic simulation process. The feasibility of characteristics line method dynamic simulation can be proved by natural gas network examples. The result shows that the simulation effect in method of characteristics is fine. It can provide reliable basis to planning, designing, scheduling, controlling, and managing for all kinds of levels. |
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