Under the fair and open operation mode of pipeline network,energy metering based on natural gas quality will gradually become the mainstream mode of natural gas trade.To realize the virtual prediction of real-time natural gas components at key nodes of the multi-source pipeline network,this paper establishes a dynamic component tracking model of multi-source gas pipeline network based on the transient simulation model of non-isothermal pipe flow and the gas component migration model.Firstly,the initial conditions of the pipeline network are obtained based on high-precision BWRS equation,steady state flow equation,enthalpy equation,gas mixing parameter equation,and boundary condition.Then the pipe flow control equation and the convection-diffusion equation are discretized by the implicit central difference method.Finally,the evolution laws of pressure,flow,temperature,component and other parameters at each node of the pipeline network over the entire transient time domain can be obtained by the time recursion method and the Newton-Rapshan method based on the physical property equations,mixing parameter relations and boundary conditions under different spatiotemporal conditions.The following results are obtained.First,the simulation results of the established steady-state model are basically accordant with the TGNET simulation results in methane and hydrogen mole fractions,and its maximum absolute deviation of system pressure and temperature are 0.069 MPa and 2.81 K respectively.Second,compared with the TGNET simulation results,the established dynamic model has the maximum absolute deviations of 0.078 MPa,2.22 K,1.54％and 0.55％in pressure,temperature,methane molar fraction and hydrogen molar fraction respectively at key nodes,indicating a high accuracy of the model prediction.Third,the proposed multi-source mixture model has a stronger universality,and is applicable to the dynamic simulation of operation parameters and the dynamic tracking of gas components in a topologically complex natural gas pipeline system.In conclusion,the real-time component tracking method proposed in this paper can provide a basis for the real-time gas component prediction of non-isothermal pipeline networks with multiple gas sources and lay a foundation for the energy metering of natural gas pipeline networks and the local development of pipeline simulation software.
关键词
天然气管网/能量计量/组分追踪/组分运移模型/中心差分法/瞬态仿真/时空演化规律/水力热力过程
Key words
Natural gas pipeline network/Energy metering/Component tracking/Component migration model/Central difference method/Transient simulation/Spatiotemporal evolution/Hydrothermal process
维普
万方数据