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Y. Xu et al.
1.1 Research Status of Steady-State Simulation of the Gas Gathering Pipeline
Network
Hardy Cross [1] et al. used computers to solve nonlinear equations of hydraulic calculation of pipeline network, which laid a foundation for the application of computers in
hydraulic analysis of pipeline networks; Michael A. Stoner [2] used Newton-Raphson
method to solve the mathematical model of nodal equation including non-pipe elements.
Acceleration factor was used to overcome the sensitivity to the initial value of calculation;
E. Benjimin Wylie [3] used Newton-Raphson to solve the problem of the steady-state
analysis of natural gas pipe network, and applied the method to the actual pipeline network; A. J. Osiadacz [4] proposed a steady-state simulation method that is suitable for
any pipeline network simulation. A numerical solution method was introduced to solve
the problem; M. R. Krstic [5] et al. introduced the Newton-Raphson method for solving
loop equations and the three methods for solving nodal equations respectively; Wang
Shouxi [6] et al. discussed the establishment of simulation model of steady-state simulation node pressure method and dynamic simulation characteristic line method. The
method is applied to development of simulation software GAS-FLOW; Li Changjun [7]
analyzed the flow state of natural gas in pipelines. Mathematical model was established
to describe its flow state, and also the gas static and dynamic simulation software named
EGPNS was developed; Zuo Lili [8, 9] solved the mathematical model of natural gas
pipeline network with the linear approximation method. The steady-state simulation
problem was extended to solve more complicated case. At the same time, the preprocessing subroutine of node number was programmed, which provided convenience for
steady state analysis; Dejan Brkic´ [10] improved the Hardy Cross method for solving
looped pipeline networks and changed the storage form of the Jacobian matrix, which
greatly improved the speed of solving the equation system; D.W. Abranham [11] et al.
established a simulation model for analyzing the gas pipeline network and analyzed the
characteristics of the compressor in detail. Newton-Raphson was applied to solve the
problem; M. Abeysekera [12] et al. considered the situation where other gases (hydrogen, biogas) were injected into the pipeline network at different locations and analyzed
the applicability of the simulation method through an example.
1.2 Research Status of Hydrate Prediction
Many researches have been focused on the phase equilibrium prediction of hydrates, and
proposed many hydrate prediction methods: phase equilibrium constant method, empirical formula method, graphic method, molecular thermodynamic model method, etc.
Among those prediction methods, the most widely used was the thermodynamic model
prediction method. Sloan and Koh [13] proposed the initial thermodynamic model of
hydrate; Later, Van der Waals and Platteeuw [14] proposed the Vdw-P model based on
the classical adsorption theory, which laid a foundation for the thermodynamic model of
hydrate prediction; Subsequently, Satio [15] proposed a complete model for hydrate prediction; The models mentioned above involve the calculation of gas component fugacity
and Langmuir constant. These two parameters have great influence on the accuracy of
the model, so many improved models are proposed for these two parameters: ParrishPrausnitz [16] model, Du-Guo [17] model, Ballard-Sloan [18] model and Javanmardi
Y. Xu et al.
1.1 Research Status of Steady-State Simulation of the Gas Gathering Pipeline
Network
Hardy Cross [1] et al. used computers to solve nonlinear equations of hydraulic calculation of pipeline network, which laid a foundation for the application of computers in
hydraulic analysis of pipeline networks; Michael A. Stoner [2] used Newton-Raphson
method to solve the mathematical model of nodal equation including non-pipe elements.
Acceleration factor was used to overcome the sensitivity to the initial value of calculation;
E. Benjimin Wylie [3] used Newton-Raphson to solve the problem of the steady-state
analysis of natural gas pipe network, and applied the method to the actual pipeline network; A. J. Osiadacz [4] proposed a steady-state simulation method that is suitable for
any pipeline network simulation. A numerical solution method was introduced to solve
the problem; M. R. Krstic [5] et al. introduced the Newton-Raphson method for solving
loop equations and the three methods for solving nodal equations respectively; Wang
Shouxi [6] et al. discussed the establishment of simulation model of steady-state simulation node pressure method and dynamic simulation characteristic line method. The
method is applied to development of simulation software GAS-FLOW; Li Changjun [7]
analyzed the flow state of natural gas in pipelines. Mathematical model was established
to describe its flow state, and also the gas static and dynamic simulation software named
EGPNS was developed; Zuo Lili [8, 9] solved the mathematical model of natural gas
pipeline network with the linear approximation method. The steady-state simulation
problem was extended to solve more complicated case. At the same time, the preprocessing subroutine of node number was programmed, which provided convenience for
steady state analysis; Dejan Brkic´ [10] improved the Hardy Cross method for solving
looped pipeline networks and changed the storage form of the Jacobian matrix, which
greatly improved the speed of solving the equation system; D.W. Abranham [11] et al.
established a simulation model for analyzing the gas pipeline network and analyzed the
characteristics of the compressor in detail. Newton-Raphson was applied to solve the
problem; M. Abeysekera [12] et al. considered the situation where other gases (hydrogen, biogas) were injected into the pipeline network at different locations and analyzed
the applicability of the simulation method through an example.
1.2 Research Status of Hydrate Prediction
Many researches have been focused on the phase equilibrium prediction of hydrates, and
proposed many hydrate prediction methods: phase equilibrium constant method, empirical formula method, graphic method, molecular thermodynamic model method, etc.
Among those prediction methods, the most widely used was the thermodynamic model
prediction method. Sloan and Koh [13] proposed the initial thermodynamic model of
hydrate; Later, Van der Waals and Platteeuw [14] proposed the Vdw-P model based on
the classical adsorption theory, which laid a foundation for the thermodynamic model of
hydrate prediction; Subsequently, Satio [15] proposed a complete model for hydrate prediction; The models mentioned above involve the calculation of gas component fugacity
and Langmuir constant. These two parameters have great influence on the accuracy of
the model, so many improved models are proposed for these two parameters: ParrishPrausnitz [16] model, Du-Guo [17] model, Ballard-Sloan [18] model and Javanmardi