Method and processor for determining energy pipe stock of natural gas pipeline network

Abstract

The embodiment of the invention provides a method for determining the energy pipe stock of a natural gas pipeline network, a processor, a storage medium and a processor. The method comprises the steps of determining a topological structure of the natural gas pipeline network based on a pipeline structure and boundary elements of the natural gas pipeline network; the flow velocity of the natural gas in each pipeline is determined according to the topological structure, a mathematical model corresponding to the flowing state of the natural gas in each pipeline is determined according to the flow velocity, and the mathematical model comprises a plurality of nonlinear equations; aiming at each pipe section, rewriting the plurality of nonlinear equations according to the two position points of the pipe section so as to obtain a target nonlinear equation corresponding to each nonlinear equation; according to the multiple target nonlinear equations, the physical property parameters of the natural gas in each pipe section are solved, and the energy pipe stock of the natural gas in each pipe section is calculated. Based on the dynamic hydraulic calculation of the natural gas pipeline network, the calculation precision of the natural gas energy pipe stock in the pipeline network and the safety of pipeline network operation can be improved, and the loss of natural gas in the transportation and trade process is reduced.

Description

Technical Field

[0001] The present application relates to the field of natural gas transportation, and in particular to a method, storage medium and processor for determining the energy pipeline inventory of a natural gas pipeline network. Background Art

[0002] The hydraulic calculation of the natural gas pipeline network is the basis for the stable operation, precise regulation and optimization analysis of the natural gas pipeline network system. As the main indicator of the peak-shaving effect of the natural gas pipeline, the pipeline storage of natural gas is an important standard to ensure the smooth and safe operation of the gas in the pipeline. For a certain gas pipeline, the pipeline storage refers to the gas volume of natural gas actually stored in the pipeline at a certain moment, that is, the volume under standard conditions. The pipeline storage calculation methods currently used in engineering projects are all based on steady-state hydraulic calculations. Compared with the dynamic process in the actual operation process, there are deviations in the calculation of energy pipeline storage and low measurement accuracy, which affects the economic benefits of the enterprise. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a method, storage medium and processor for determining the energy pipeline inventory of a natural gas pipeline network.

[0004] In order to achieve the above-mentioned object, the first aspect of the present application provides a method for determining the energy pipeline inventory of a natural gas pipeline network, comprising:

[0005] Determine the topological structure of the natural gas pipeline network based on the pipeline structure and boundary elements of the natural gas pipeline network, the topological structure includes multiple pipelines of the natural gas pipeline network, nodes corresponding to each pipeline, and the flow direction of natural gas in each pipeline, each pipeline includes multiple pipe segments, and a pipe segment refers to a pipeline between two adjacent location points;

[0006] Determine the flow rate of natural gas in each pipeline based on the topological structure;

[0007] For each pipeline, a mathematical model corresponding to the flow state of the natural gas in the pipeline is determined according to the flow velocity, and the mathematical model includes a plurality of nonlinear equations;

[0008] For each pipe section of each pipeline, multiple nonlinear equations are rewritten according to two position points of the pipe section to obtain a target nonlinear equation corresponding to each nonlinear equation;

[0009] Determine the physical property parameters of natural gas in each pipeline section according to multiple target nonlinear equations;

[0010] Determine the energy pipeline inventory of natural gas in each pipeline section based on physical property parameters.

[0011] In an embodiment of the present application, the node corresponding to each pipeline includes a first node and a second node, and determining the flow rate of natural gas in each pipeline according to the topological structure includes: for each pipeline, obtaining a first pressure of the first node and a second pressure of the second node; for each pipeline, determining a first pressure column vector between the first node and the second node according to the first pressure and the second pressure; determining a reduced-order association matrix corresponding to the natural gas pipeline network according to the topological structure; for each pipeline, determining a second pressure column vector corresponding to all pipelines according to the first pressure column vector and the reduced-order association matrix; determining a first flow column vector corresponding to all pipelines according to the second pressure column vector; for each pipeline, determining a second flow column vector corresponding to the pipeline according to the first flow column vector and the reduced-order association matrix; for each pipeline, determining a flow rate of natural gas in the pipeline according to the second flow column vector.

[0012] In an embodiment of the present application, the multiple nonlinear equations include a state equation, the mixture of natural gas includes multiple gas components, and the method further includes: obtaining the volume fraction of each gas component; for each pipeline, determining the density of the natural gas when it is in the pipeline based on the state equation according to the total volume fraction and the first pressure column vector.

[0013] In an embodiment of the present application, for each pipeline, determining the density of the natural gas in the pipeline based on the state equation according to the total volume fraction and the first pressure column vector includes calculating the density according to the following formula (1):

[0014]

[0015] Among them, p refers to the first pressure column vector of natural gas in each pipeline, ρ refers to the density of natural gas in each pipeline, R is the universal gas constant, T is the system temperature, A0, B0, C0, D0, a, α, b, d, γ refer to the different Viral coefficients of gas components in the natural gas mixture.

[0016] In an embodiment of the present application, the nonlinear equation includes a momentum equation. For each pipeline, a mathematical model corresponding to the flow state of natural gas in the pipeline is determined according to the flow velocity. The mathematical model includes multiple nonlinear equations including: for each pipeline, the Reynolds number of the natural gas in the pipeline is determined according to the density and flow velocity; the diameter and actual roughness of each pipeline are obtained; for each pipeline, the friction resistance coefficient of the pipeline is determined according to the Reynolds number, diameter and actual roughness; for each pipeline, the momentum equation is determined according to the friction resistance coefficient, diameter and flow velocity.

[0017] In an embodiment of the present application, the multiple target nonlinear equations include a target continuity equation, a target momentum equation, a target energy equation, and a target state equation, and the physical property parameters include multiple parameters to be determined, each pipe section corresponds to multiple parameters to be determined, and each parameter to be determined includes multiple parameter values ​​to be determined corresponding to multiple pipe sections; determining the physical property parameters of natural gas in each pipe section according to the multiple target nonlinear equations includes: for each parameter to be determined, determining the iteration matrix corresponding to the parameter to be determined according to the multiple parameter values ​​to be determined; for each parameter to be determined, performing multiple iterative calculations on the parameter to be determined according to the iteration matrix; for each iterative calculation, determining the iterative increment corresponding to the iterative calculation according to the iteration matrix, the number of iterations corresponding to the iterative calculation, and the multiple target nonlinear equations; for each parameter to be determined, determining multiple calculation results after multiple iterative calculations according to the multiple iterative increments, the multiple iterative matrices, and the multiple target nonlinear equations, and determining the multiple calculation results as multiple parameter values ​​to be determined; determining the physical property parameters of natural gas in each pipe section according to all the parameter values ​​to be determined for the multiple parameters to be determined.

[0018] In an embodiment of the present application, for each parameter to be determined, determining an iteration matrix corresponding to the parameter to be determined according to multiple parameter values ​​to be determined includes determining the iteration matrix according to the following formula (2):

[0019]

[0020] Among them, x0…x n-1 refers to the value of each parameter to be determined, f0…f n-1 Refers to multiple target nonlinear equations corresponding to each parameter value to be determined, and J refers to the iteration matrix corresponding to each parameter to be determined.

[0021] In an embodiment of the present application, for each iterative calculation, determining the iterative increment corresponding to the iterative calculation according to the iterative matrix, the number of iterations corresponding to the iterative calculation, and the multiple target nonlinear equations includes determining the iterative increment according to the following formula (3):

[0022] J k δX k =f(X k ) (3)

[0023] Among them, k refers to the number of iterations calculated in each iteration, J k refers to the iteration matrix corresponding to the kth iteration calculation, X refers to the parameter value of each parameter to be calculated corresponding to each pipeline section of natural gas, δX k It refers to the iteration increment corresponding to the iterative calculation, f(X k ) refers to the multiple non-target nonlinear equations corresponding to the k-th iteration calculation.

[0024] In an embodiment of the present application, for each pipe section of each pipeline, the target nonlinear equation corresponding to each nonlinear equation is obtained by rewriting the target nonlinear equation according to two position points of the pipe section. The target nonlinear equations include the following formulas (4)(5)(6)(7)(8):

[0025]

[0026] Where t refers to the time, i refers to the i-th position point of each pipeline, and i+1 refers to the next position point of each pipeline adjacent to the i-th position point. It refers to the density of natural gas at the i-th point in each pipeline at time t. It refers to the flow rate of natural gas at the i-th position in each pipeline at time t, Δt refers to the time step of setting calculation, and Δx refers to the spatial step of each pipe section. It refers to the pressure of natural gas at the i-th point in each pipeline at time t; It refers to the enthalpy of natural gas at the i-th position of each pipeline at time t. It refers to the mole fraction of gas component n at the i-th position in each pipeline at time t, g refers to the acceleration of gravity, θ refers to the pipeline inclination of each pipeline, λ refers to the actual roughness of each pipeline, D is the diameter of each pipeline, T0 refers to the ambient temperature, K refers to the comprehensive heat transfer coefficient, and Z refers to the compression factor.

[0027] In an embodiment of the present application, the physical property parameters include the first temperature and the second temperature, as well as the first pressure and the second pressure, of the natural gas corresponding to two position points of each pipe section respectively, and the energy pipe inventory of the natural gas in each pipe section is determined according to the physical property parameters: for each pipe section, the average temperature of the pipe section is determined according to the first temperature and the second temperature; for each pipe section, the average pressure of the pipe section is determined according to the first pressure and the second pressure; for each pipe section, the first pipe inventory of the pipe section is determined according to the average temperature and the average pressure; for each pipeline, the second pipe inventory of the pipeline is determined according to the first pipe inventory of all the pipe sections; for each pipeline, the energy pipe inventory of the pipeline is determined according to the second pipe inventory.

[0028] In an embodiment of the present application, the physical property parameters also include the molar fraction of each gas component of the natural gas in each pipe section. For each pipeline, determining the energy pipe inventory of the pipeline according to the second pipe inventory includes: for each pipe section, determining the actual high molar calorific value of the natural gas in the pipe section according to all the molar fractions, and using the actual high molar calorific value of the pipe section as the actual high molar calorific value of the natural gas in the pipeline corresponding to the pipe section; for each pipeline, determining the energy pipe inventory of the natural gas in the pipeline according to the actual high molar calorific value and the second pipe inventory.

[0029] A second aspect of the present application provides a processor configured to execute the above-mentioned method for determining the energy pipeline inventory of a natural gas pipeline network.

[0030] A third aspect of the present application provides a machine-readable storage medium having instructions stored thereon, which, when executed by a processor, configure the processor to execute the above-mentioned method for determining the energy pipe inventory of a natural gas pipeline network.

[0031] Through the above technical scheme, the topological structure of the natural gas pipeline network is determined based on the pipeline structure and boundary elements of the natural gas pipeline network. The topological structure includes multiple pipelines of the natural gas pipeline network, nodes corresponding to each pipeline, and the flow direction of natural gas in each pipeline. Each pipeline includes multiple pipe sections, and the pipe section refers to the pipeline between two adjacent position points; the flow rate of natural gas in each pipeline is determined according to the topological structure; for each pipeline, the mathematical model corresponding to the flow state of natural gas in the pipeline is determined according to the flow rate, and the mathematical model includes multiple nonlinear equations; for each pipe section of each pipeline, the multiple nonlinear equations are rewritten according to the two position points of the pipe section to obtain the target nonlinear equation corresponding to each nonlinear equation; the physical parameters of natural gas in each pipe section are determined according to the multiple target nonlinear equations; the energy pipe stock of natural gas in each pipe section is determined according to the physical parameters. Based on the dynamic hydraulic calculation of the natural gas pipeline network, the calculation accuracy of the energy pipe stock of natural gas in the pipeline network can be improved, the safety of the operation of the natural gas pipeline network can be improved, and the loss of natural gas can be reduced during transportation and trade.

[0032] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the accompanying drawings:

[0034] Figure 1 A schematic diagram of a process flow of a method for determining energy pipeline inventory of a natural gas pipeline network according to an embodiment of the present application is schematically shown;

[0035] Figure 2 The topological structure diagram of the natural gas pipeline network according to the embodiment of the present application is schematically shown;

[0036] Figure 3 The internal structure diagram of a computer device according to an embodiment of the present application is schematically shown. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific implementation methods described herein are only used to illustrate and explain the embodiments of the present application, and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0038] Figure 1 The flowchart of the method for determining the energy pipeline inventory of the natural gas pipeline network according to an embodiment of the present application is schematically shown. Figure 1 As shown, in one embodiment of the present application, a method for determining the energy pipeline inventory of a natural gas pipeline network is provided, comprising the following steps:

[0039] S102, determining the topological structure of the natural gas pipeline network based on the pipeline structure and boundary elements of the natural gas pipeline network, the topological structure includes multiple pipelines of the natural gas pipeline network, nodes corresponding to each pipeline, and the flow direction of natural gas in each pipeline, each pipeline includes multiple pipe segments, and a pipe segment refers to a pipeline between two adjacent location points.

[0040] S104, determining the flow rate of the natural gas in each pipeline according to the topological structure.

[0041] S106, for each pipeline, determining a mathematical model corresponding to the flow state of the natural gas in the pipeline according to the flow velocity, wherein the mathematical model includes a plurality of nonlinear equations.

[0042] S108, for each pipe section of each pipeline, rewrite the multiple nonlinear equations according to the two position points of the pipe section to obtain a target nonlinear equation corresponding to each nonlinear equation.

[0043] S110, determining the physical property parameters of the natural gas in each pipeline section according to a plurality of target nonlinear equations.

[0044] S112, determining the energy pipeline inventory of natural gas in each pipeline section according to the physical property parameters.

[0045] The boundary elements of the natural gas pipeline network include pressure boundaries, temperature boundaries, flow boundaries, etc. The processor can establish the topological structure of the natural gas pipeline network based on the pipeline structure of the natural gas pipeline network and the above-mentioned boundary elements. The topological structure includes multiple pipelines of the natural gas pipeline network, nodes corresponding to each pipeline, and the flow direction of natural gas in each pipeline. The nodes corresponding to each pipeline can be gas sources, users, gas storages, heat exchangers, and valves in the natural gas pipeline network. Each pipeline includes multiple pipe sections, and a pipe section refers to a pipeline between two adjacent locations. Since natural gas is dynamic in the natural gas pipeline network, the state of natural gas in each pipeline is not the same. Therefore, the processor can analyze the mutual influence between pipelines and pipelines and between pipelines and nodes according to the topological structure to determine the flow rate of natural gas in each pipeline. Then, according to the flow rate of each pipeline, a mathematical model corresponding to each pipeline can be established. The mathematical model can characterize the flow characteristics of natural gas in the pipeline. The mathematical model includes multiple nonlinear equations, namely, energy equations, state equations, continuity equations, momentum equations, and component transport equations. In order to analyze the dynamic natural gas in the natural gas pipeline network, a mathematical model can be established for the pipe sections in the pipeline. Specifically, the processor can perform differential rewriting of the energy equation, state equation, continuity equation, momentum equation and component transport equation corresponding to the pipeline where the pipe section is located through two position points of each pipe section, thereby obtaining multiple target nonlinear equations. The target nonlinear equation refers to the equation after the nonlinear equation is rewritten. The processor can perform dynamic simulation calculation on the pipe section according to the energy equation, state equation, continuity equation, momentum equation and component transport equation rewritten by the difference to obtain the physical property parameters of the pipe section. The physical property parameters include temperature, pressure, gas component, flow rate, etc. According to the above physical property parameters, the processor can calculate the energy pipe inventory of natural gas in each pipe section. Compared with the calculation results of the traditional steady-state simulation simulation to calculate the volume pipe inventory, the embodiment of the present application takes into account that the natural gas is actually dynamically operated in the pipeline network to calculate the energy pipe inventory of each small section in the pipeline, improve the calculation accuracy of the natural gas energy pipe inventory in the pipeline network, and reduce the loss of natural gas during transportation and trade.

[0046] In one embodiment, the node corresponding to each pipeline includes a first node and a second node, and determining the flow rate of natural gas in each pipeline according to the topological structure includes: for each pipeline, obtaining a first pressure of the first node and a second pressure of the second node; for each pipeline, determining a first pressure column vector between the first node and the second node according to the first pressure and the second pressure; determining a reduced-order association matrix corresponding to the natural gas pipeline network according to the topological structure; for each pipeline, determining a second pressure column vector corresponding to all pipelines according to the first pressure column vector and the reduced-order association matrix; determining a first flow column vector corresponding to all pipelines according to the second pressure column vector; for each pipeline, determining a second flow column vector corresponding to the pipeline according to the first flow column vector and the reduced-order association matrix; for each pipeline, determining a flow rate of natural gas in the pipeline according to the second flow column vector.

[0047] The first node and the second node are the beginning and the end of the pipeline. The processor can remove the first pressure of the first node of each pipeline and the second pressure of the second node to calculate the first pressure column vector between the first node and the second node. The first pressure column vector refers to the pressure difference between the first node and the second node when the natural gas flows from the first node to the second node. Figure 2 , Figure 2 A schematic diagram schematically shows a topological structure diagram of a natural gas pipeline network in an embodiment of the present application. Figure 2 The natural gas in the natural gas pipeline network flows from the gas source to the user through the natural gas pipeline network, and the nodes and line segments (pipelines) of the topological structure of the natural gas pipeline network. The processor can determine the reduced-order association matrix of the natural gas pipeline network based on the nodes and pipelines in the topological structure. The processor can calculate the second pressure column vector composed of the pressures of all pipelines in the natural gas pipeline network through the reduced-order association matrix and the first pressure column vector. Specifically, the second pressure column vector can be calculated according to the following formula (9):

[0048] A T P=Δ (9)

[0049] Among them, Δ refers to the second pressure column vector composed of the pressures of all pipelines in the natural gas pipeline network, P refers to the first pressure column vector corresponding to each pipeline, and A T It refers to the transposed matrix of the reduced-order incidence matrix of (-1)×M, N refers to the number of nodes in the natural gas pipeline network, and M refers to the number of pipelines in the natural gas pipeline network.

[0050] Furthermore, the processor may calculate a first flow column vector composed of the flows of all pipelines in the natural gas pipeline network according to the second pressure column vector. Specifically, the first flow column vector may be calculated according to the following formula (10):

[0051] Δ=S|q|q+ZH p (10)

[0052] Among them, Δ refers to the second pressure column vector composed of the pressures of all pipelines in the natural gas pipeline network, S refers to the M×M order resistance coefficient diagonal matrix, q refers to the first flow column vector composed of the flow of all pipelines in the natural gas pipeline network, |q| refers to the M×M order pipeline flow absolute value diagonal matrix, Z refers to the potential energy difference vector between two nodes in each pipeline branch, H P Refers to the lift vector of the compressor in each pipeline.

[0053] Then, the processor can determine the second flow column vector corresponding to each pipeline according to the first flow column vector and the reduced-order association matrix. The second flow column vector refers to the flow of natural gas between the first node and the second node when the natural gas flows from the first node through the second node. Specifically, the second flow column vector can be calculated according to the following formula (11):

[0054] Aq=Q (11)

[0055] Wherein, A refers to a reduced-order association matrix of (-1)×M, q refers to a first flow column vector composed of the flows of all pipelines in the natural gas pipeline network, and Q refers to a second flow column vector corresponding to each pipeline.

[0056] Then, the processor can determine the flow rate of the natural gas in each pipeline according to the second flow column vector of each pipeline. Specifically, the flow rate can be calculated according to the following formula (12):

[0057]

[0058] Wherein, Q refers to the second flow column vector corresponding to each pipeline, ω refers to the flow rate of natural gas in each pipeline, and D refers to the diameter of each pipeline.

[0059] In one embodiment, the multiple nonlinear equations include a state equation, the mixture of natural gas includes multiple gas components, and the method further includes: obtaining the volume fraction of each gas component; for each pipeline, determining the density of the natural gas when it is in the pipeline based on the state equation according to the total volume fraction and the first pressure column vector.

[0060] The mixture of natural gas includes multiple gas components, and the volume fraction of each gas component is the volume fraction of the gas component of the natural gas transported by the gas source. For each pipeline, the processor can determine the density of the natural gas in the pipeline based on the state equation according to all volume fractions and the first pressure column vector, including calculating the density according to the following formula (1):

[0061]

[0062] Among them, p refers to the first pressure column vector of natural gas in each pipeline, ρ refers to the density of natural gas in each pipeline, R is the universal gas constant, T is the system temperature, A0, B0, C0, D0, a, α, b, d, γ refer to the different Viral coefficients of gas components in the natural gas mixture. B0=∑ i y i B 0i , i refers to gas component i, j refers to gas component j, y i refers to the volume fraction of gas component i in the natural gas mixture, y j refers to the volume fraction of gas component j in the natural gas mixture, K ij is the interaction coefficient between gas component i and gas component j, a i 、b i 、c i ,d i , α i , γ i It refers to the Viral coefficient of different gas components i in the natural gas mixture. The density value is obtained by solving the equation by iteration method under given system temperature, pressure and volume fraction of gas components.

[0063] In one embodiment, the nonlinear equation includes a momentum equation. For each pipeline, a mathematical model corresponding to the flow state of natural gas in the pipeline is determined according to the flow velocity. The mathematical model includes multiple nonlinear equations including: for each pipeline, the Reynolds number of the natural gas in the pipeline is determined according to the density and flow velocity; the diameter and actual roughness of each pipeline are obtained; for each pipeline, the friction resistance coefficient of the pipeline is determined according to the Reynolds number, diameter and actual roughness; for each pipeline, the momentum equation is determined according to the friction resistance coefficient, diameter and flow velocity.

[0064] After the density of the pipeline is calculated by the above state equation, the processor can calculate the Reynolds number of the natural gas in the pipeline through the density and flow rate of the pipeline. Then the diameter and actual roughness of the pipeline are obtained, and the friction resistance coefficient of the pipeline is calculated according to the Reynolds number, diameter and actual roughness. Specifically, the processor can calculate the friction resistance coefficient according to the following formula (13):

[0065]

[0066] Among them, λ refers to the friction resistance coefficient of each pipeline, D refers to the diameter of each pipeline, ε refers to the actual roughness of each pipeline, and Re refers to the Reynolds number of natural gas in each pipeline.

[0067] In one embodiment, the multiple target nonlinear equations include a target continuity equation, a target momentum equation, a target energy equation, and a target state equation. For each pipe section of each pipeline, the multiple nonlinear equations are implicitly rewritten according to two position points of the pipe section to obtain a target nonlinear equation corresponding to each nonlinear equation. The multiple target nonlinear equations include the following formulas (4)(5)(6)(7)(8):

[0068]

[0069] Where t refers to the time, i refers to the i-th position point of each pipeline, and i+1 refers to the next position point of each pipeline adjacent to the i-th position point. It refers to the density of natural gas at the i-th point in each pipeline at time t. It refers to the flow rate of natural gas at the i-th position in each pipeline at time t, Δt refers to the time step of setting calculation, and Δx refers to the spatial step of each pipe section. It refers to the pressure of natural gas at the i-th point in each pipeline at time t; It refers to the enthalpy of natural gas at the i-th position of each pipeline at time t. It refers to the mole fraction of gas component n at the i-th position in each pipeline at time t, g refers to the acceleration of gravity, θ refers to the pipeline inclination of each pipeline, λ refers to the actual roughness of each pipeline, D is the diameter of each pipeline, T0 refers to the ambient temperature, K refers to the comprehensive heat transfer coefficient, and Z refers to the compression factor.

[0070] In one embodiment, the multiple target nonlinear equations include a target continuity equation, a target momentum equation, a target energy equation, and a target state equation, and the physical property parameters include multiple parameters to be determined, each pipe section corresponds to multiple parameters to be determined, and each parameter to be determined includes multiple parameter values ​​to be determined corresponding to multiple pipe sections; determining the physical property parameters of natural gas in each pipe section according to the multiple target nonlinear equations includes: for each parameter to be determined, determining an iteration matrix corresponding to the parameter to be determined according to multiple parameter values ​​to be determined; for each parameter to be determined, performing multiple iterative calculations on the parameter to be determined according to the iteration matrix; for each iterative calculation, determining an iteration increment corresponding to the iterative calculation according to the iteration matrix, the number of iterations corresponding to the iterative calculation, and the multiple target nonlinear equations; for each parameter to be determined, determining multiple calculation results after multiple iterative calculations according to the multiple iteration increments, the multiple iteration matrices, and the multiple target nonlinear equations, and determining the multiple calculation results as multiple parameter values ​​to be determined; determining the physical property parameters of natural gas in each pipe section according to all the parameter values ​​to be determined for the multiple parameters to be determined.

[0071] The physical property parameters include multiple parameters to be determined, such as temperature, pressure, gas composition, flow rate, etc. Since natural gas flows in the pipeline network, the physical property parameters of natural gas are different at each pipe section of each pipeline. Therefore, each parameter to be determined of natural gas has different parameter values ​​at different pipe sections. The processor can solve the parameter values ​​of each parameter to be determined of natural gas at each pipe section through multiple target nonlinear equations.

[0072] In one embodiment, for each parameter to be determined, the processor can establish an iteration matrix corresponding to the parameter to be determined based on multiple unknown parameter values ​​corresponding to different pipe sections. Specifically, the processor can determine the iteration matrix according to the following formula (2):

[0073]

[0074] Among them, x0…x n-1 refers to the value of each parameter to be determined, f0…f n-1 Refers to multiple target nonlinear equations corresponding to each parameter value to be determined, and J refers to the iteration matrix corresponding to each parameter to be determined. The iteration matrix is ​​the Jacobian matrix.

[0075] In one embodiment, multiple target nonlinear equations f i (X) represents different locations (pipe sections), and the physical parameters of different locations of the natural gas pipeline network are simulated and solved. X refers to the different locations (pipe sections) and refers to the parameter values ​​of each parameter to be determined corresponding to the natural gas in different pipe sections. The vector composed of X is X=(x0,x1,x2...x n-1 ) T . For multiple objective nonlinear equations f i (X) performs iterative calculations, assuming that the approximate value of the kth iterative calculation is X k =(x0 k ,x1 k ,x2 k ...x n-1 k ) T .

[0076] Then, according to the Newton-Raphson method, the iterative increment of each iteration calculation is δX=(δx0,x1,x2...x n-1 ). That is, X k+1 = k -X k . Where 0, 1, 2...n-1 refer to different pipe segments. Then, for each iterative calculation, the processor can determine the iterative increment corresponding to the iterative calculation according to the iterative matrix, the number of iterations corresponding to the iterative calculation, and multiple target nonlinear equations. Specifically, the processor can determine the iterative increment according to the following formula (3):

[0077] J k δX k =f(X k ) (3)

[0078] Among them, k refers to the number of iterations calculated in each iteration, J k refers to the iteration matrix corresponding to the kth iteration calculation, X refers to the parameter value of each parameter to be calculated corresponding to each pipeline section of natural gas, δX k It refers to the iteration increment corresponding to the iterative calculation, f(X k ) refers to the multiple target nonlinear equations corresponding to the k-th iteration calculation.

[0079] In one embodiment, the processor can divide the spatial grid according to the length of the pipeline to obtain the spatial step. The iteration time is determined according to the time interval of the sampling time of the measuring instrument such as the chromatograph to divide the time grid to obtain the time step. For each parameter to be determined, according to multiple iteration increments, multiple iteration matrices, and the above-mentioned target nonlinear equations (4)(5)(6)(7)(8), multiple calculation results are calculated and determined as multiple parameter values ​​to be determined. The density, flow rate, gas composition, pressure, temperature, enthalpy and other physical parameters of each spatial grid point (i.e., each pipe section and each node) in the natural gas pipeline network are determined by multiple parameter values ​​to be determined.

[0080] In one embodiment, the physical property parameters include the first temperature and the second temperature, and the first pressure and the second pressure, of the natural gas corresponding to two position points of each pipe section respectively, and the energy pipeline inventory of the natural gas in each pipe section is determined according to the physical property parameters: for each pipe section, the average temperature of the pipe section is determined according to the first temperature and the second temperature; for each pipe section, the average pressure of the pipe section is determined according to the first pressure and the second pressure; for each pipe section, the first pipeline inventory of the pipe section is determined according to the average temperature and the average pressure; for each pipeline, the second pipeline inventory of the pipeline is determined according to the first pipeline inventory of all the pipe sections; for each pipeline, the energy pipeline inventory of the pipeline is determined according to the second pipeline inventory.

[0081] The two position points of each pipe section include a first position point and a second position point, the first position point and the second position point correspond to the flow direction of natural gas in the pipeline, and the natural gas flows from the first position point to the second position point. The first temperature refers to the temperature of the natural gas at the first position point, and the second temperature refers to the temperature of the natural gas at the second position point. The processor can determine the energy pipe inventory of the natural gas in each pipe section according to the physical property parameters of the natural gas in each pipe section.

[0082] Specifically, for each pipe segment, the processor may determine the average temperature of the pipe segment according to the first temperature and the second temperature. The average temperature may be calculated according to the following formula (14):

[0083]

[0084] Where i refers to the first position point of each pipe segment, j refers to the second position point of each pipe segment, and T i Refers to the first temperature of the first position point of each pipe section, T j Refers to the second temperature of the second position point of each pipe section, T ij It refers to the average temperature of natural gas in each pipeline section.

[0085] For each pipe segment, the processor may determine an average pressure of the pipe segment according to the first pressure and the second pressure, wherein the average pressure may be calculated according to the following formula (15):

[0086]

[0087] Where i refers to the first position point of each pipe segment, j refers to the second position point of each pipe segment, and p i Refers to the first pressure at the first position of each pipe section, p j Refers to the second pressure at the second position of each pipe section, p ij The average pressure of natural gas in each pipeline section.

[0088] For each pipe segment, the first pipe storage of the pipe segment is determined according to the average temperature and the average pressure. The processor may calculate the first pipe storage according to the following formula (16):

[0089]

[0090] Where m refers to the mth pipe segment, V m refers to the first storage of natural gas in the mth pipeline section, V0 refers to the fixed volume of the mth pipeline section, p ij The average pressure of natural gas in the mth pipeline section, p0 refers to the pressure under reference conditions, T0 refers to the temperature under reference conditions, T ij It refers to the average temperature of the mth pipe section, Z1 refers to the compression factor corresponding to the mth pipe section, and Z2 refers to the compression factor under reference conditions.

[0091] For each pipeline, the second pipeline storage of the pipeline is determined according to the first pipeline storage of all pipeline sections. The first pipeline storage refers to the volume of natural gas in a certain pipeline section of the pipeline. The second pipeline storage refers to the volume of natural gas in the pipeline.

[0092] The processor may calculate the second storage according to the following formula (17):

[0093]

[0094] Where V is the second pipe storage of each pipe, V mIt refers to the first pipe storage of every m pipe sections in each pipeline.

[0095] In one embodiment, the physical property parameters also include the molar fraction of each gas component of the natural gas in each pipe section. For each pipeline, determining the energy pipe inventory of the pipeline according to the second pipe inventory includes: for each pipe section, determining the actual high molar calorific value of the natural gas in the pipe section according to all the molar fractions, and using the actual high molar calorific value of the pipe section as the actual high molar calorific value of the natural gas in the pipeline corresponding to the pipe section; for each pipeline, determining the energy pipe inventory of the natural gas in the pipeline according to the actual high molar calorific value and the second pipe inventory.

[0096] Specifically, after the natural gas is mixed in the pipeline, the gas components inside the pipeline are basically in a stable transition state. Then, the processor can determine the actual high molar calorific value of the natural gas in the pipeline section according to the total molar fractions corresponding to each pipeline section, as the actual high molar calorific value of the natural gas in the pipeline where the pipeline section is located. The processor can calculate the actual high molar calorific value of the natural gas in the pipeline according to the following formula (18):

[0097]

[0098] Among them, x i refers to the mole fraction of gas component i in each pipeline, t1 refers to the combustion reference temperature, It refers to the actual high-order molar calorific value of gas component i in each pipeline. Refers to the ideal high molar calorific value of each pipeline natural gas gas fuel, (H c ) G (t1) refers to the actual high molar calorific value of the gas fuel of each pipeline natural gas.

[0099] Furthermore, for each pipeline, the processor can calculate the energy pipe inventory of natural gas in the pipeline according to the actual high-order molar calorific value and the second pipe inventory. The processor can calculate the energy pipe inventory of natural gas in the pipeline according to the following formula (19):

[0100] H=(H c ) G (t1)V / 22.4 (19)

[0101] Where t1 refers to the combustion reference temperature, (H c ) G (t1) refers to the actual high molar calorific value of the gas fuel of each pipeline natural gas, and H refers to the energy pipeline inventory of natural gas in each pipeline.

[0102] Through the above technical scheme, the topological structure of the natural gas pipeline network is determined based on the pipeline structure and boundary elements of the natural gas pipeline network, and the mutual influence between pipelines in the pipeline network is considered, and the flow rate of natural gas in each pipeline is determined according to the topological structure. For each pipeline, the mathematical model corresponding to the flow state of natural gas in the pipeline is determined according to the flow rate. The mathematical model includes multiple nonlinear equations, such as energy equation, state equation, continuity equation, momentum equation and component transport equation. For each section of each pipeline, multiple nonlinear equations are implicitly rewritten according to two position points of the section to obtain the target nonlinear equation corresponding to each nonlinear equation. The multiple target nonlinear equations are iteratively calculated by Newton's method to determine the physical parameters of natural gas in each section and each node in the natural gas pipeline network. The energy pipe stock of natural gas in each section is determined according to the physical parameters. The dynamic hydraulic calculation based on the natural gas pipeline network has higher calculation accuracy than the steady-state calculation. At the same time, the safety of the operation of the natural gas pipeline network is improved, so that the loss of natural gas in the transportation and trade process is reduced.

[0103] Figure 1 FIG. 1 is a flow chart of a method for determining the energy pipeline inventory of a natural gas pipeline network in one embodiment. It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0104] The processor includes a kernel, and the kernel calls the corresponding program unit from the memory. One or more kernels can be set, and the method for determining the energy pipe inventory of the natural gas pipeline network is implemented by adjusting kernel parameters.

[0105] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0106] An embodiment of the present application provides a storage medium on which a program is stored. When the program is executed by a processor, the method for determining the energy pipeline inventory of a natural gas pipeline network is implemented.

[0107] An embodiment of the present application provides a processor, which is used to run a program, wherein the program executes the above-mentioned method for determining the energy pipeline inventory of a natural gas pipeline network when running.

[0108] In one embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as follows: Figure 3 As shown. The computer device includes a processor A01, a network interface A02, a memory (not shown in the figure) and a database (not shown in the figure) connected via a system bus. Among them, the processor A01 of the computer device is used to provide computing and control capabilities. The memory of the computer device includes an internal memory A03 and a non-volatile storage medium A04. The non-volatile storage medium A04 stores an operating system B01, a computer program B02 and a database (not shown in the figure). The internal memory A03 provides an environment for the operation of the operating system B01 and the computer program B02 in the non-volatile storage medium A04. The database of the computer device is used to store data for a method for determining the energy pipe inventory of a natural gas pipeline network. The network interface A02 of the computer device is used to communicate with an external terminal through a network connection. When the computer program B02 is executed by the processor A01, a method for determining the energy pipe inventory of a natural gas pipeline network is implemented.

[0109] Those skilled in the art will understand that Figure 3 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0110] An embodiment of the present application provides a device, which includes a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, the steps of a method for determining the energy pipe inventory of a natural gas pipeline network are implemented.

[0111] The present application also provides a computer program product, which, when executed on a data processing device, is suitable for executing a program that initializes the method steps for determining the energy pipeline inventory of a natural gas pipeline network.

[0112] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0113] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0114] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0115] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0116] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0117] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0118] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0119] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0120] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A method for determining the energy pipeline inventory of a natural gas pipeline network, characterized in that: The method comprises: Determine a topological structure of the natural gas pipeline network based on the pipeline structure and boundary elements of the natural gas pipeline network, wherein the topological structure includes multiple pipelines of the natural gas pipeline network, nodes corresponding to each pipeline, and a flow direction of natural gas in each pipeline, wherein each pipeline includes multiple pipe segments, and a pipe segment refers to a pipeline between two adjacent position points; determining the flow rate of natural gas in each pipeline according to the topological structure; For each pipeline, determining a mathematical model corresponding to the flow state of the natural gas in the pipeline according to the flow velocity, wherein the mathematical model includes a plurality of nonlinear equations; For each pipe section of each pipeline, rewrite the multiple nonlinear equations according to two position points of the pipe section to obtain a target nonlinear equation corresponding to each nonlinear equation; Determine the physical property parameters of natural gas in each pipeline section according to multiple target nonlinear equations; The energy pipeline inventory of natural gas in each pipeline section is determined according to the physical property parameters.

2. The method for determining the energy pipeline inventory of a natural gas pipeline network according to claim 1, characterized in that: The nodes corresponding to each pipeline include a first node and a second node, and determining the flow rate of natural gas in each pipeline according to the topological structure includes: For each pipeline, obtaining a first pressure of the first node and a second pressure of the second node; For each pipeline, determining a first pressure column vector between the first node and the second node according to the first pressure and the second pressure; Determine a reduced-order association matrix corresponding to the natural gas pipeline network according to the topological structure; For each pipeline, determining the second pressure column vectors corresponding to all pipelines according to the first pressure column vector and the reduced-order correlation matrix; Determine the first flow column vectors corresponding to all pipelines according to the second pressure column vector; For each pipeline, determining a second flow column vector corresponding to the pipeline according to the first flow column vector and the reduced-order association matrix; For each pipeline, the flow rate of the natural gas in the pipeline is determined according to the second flow column vector.

3. The method for determining the energy pipeline inventory of a natural gas pipeline network according to claim 2, characterized in that: The plurality of nonlinear equations include an equation of state, the mixture of natural gas includes a plurality of gas components, and the method further includes: Get the volume fraction of each gas component; For each pipeline, the density of the natural gas in the pipeline is determined based on the state equation according to the total volume fraction and the first pressure column vector.

4. The method for determining the energy pipeline inventory of a natural gas pipeline network according to claim 3, characterized in that: The step of determining the density of the natural gas in each pipeline based on the state equation according to the total volume fraction and the first pressure column vector comprises calculating the density according to the following formula (1): Among them, p refers to the first pressure column vector of natural gas in each pipeline, ρ refers to the density of natural gas in each pipeline, R is the universal gas constant, T is the system temperature, A0, B0, C0, D0, a, α, b, d, γ refer to the different Viral coefficients of gas components in the natural gas mixture.

5. The method for determining the energy pipeline inventory of a natural gas pipeline network according to claim 3, characterized in that: The nonlinear equation includes a momentum equation. For each pipeline, a mathematical model corresponding to the flow state of the natural gas in the pipeline is determined according to the flow velocity. The mathematical model includes a plurality of nonlinear equations including: For each pipeline, determining the Reynolds number of the natural gas in the pipeline according to the density and the flow velocity; Get the diameter and actual roughness of each pipe; For each pipeline, determining the friction resistance coefficient of the pipeline according to the Reynolds number, the diameter and the actual roughness; For each pipeline, the momentum equation is determined according to the friction resistance coefficient, the diameter, and the flow velocity.

6. The method for determining the energy pipeline inventory of a natural gas pipeline network according to claim 1, characterized in that: The multiple target nonlinear equations include a target continuity equation, a target momentum equation, a target energy equation, and a target state equation. The physical property parameters include multiple parameters to be determined. Each pipe segment corresponds to multiple parameters to be determined. Each parameter to be determined includes multiple parameter values ​​corresponding to multiple pipe segments. Determining the physical property parameters of natural gas in each pipe section according to multiple target nonlinear equations includes: For each parameter to be determined, determining an iteration matrix corresponding to the parameter to be determined according to the multiple values ​​of the parameter to be determined; For each parameter to be determined, performing multiple iterative calculations on the parameter to be determined according to the iteration matrix; For each iterative calculation, determining an iterative increment corresponding to the iterative calculation according to the iterative matrix, the number of iterations corresponding to the iterative calculation and the multiple target nonlinear equations; For each parameter to be determined, a plurality of calculation results after the plurality of iterative calculations are determined according to a plurality of iterative increments, a plurality of iterative matrices, and the plurality of target nonlinear equations, and the plurality of calculation results are determined as the plurality of parameter values ​​to be determined; The physical property parameters of the natural gas in each pipe section are determined according to all the parameter values ​​of the multiple parameters to be determined.

7. The method for determining the energy pipeline inventory of a natural gas pipeline network according to claim 6, characterized in that: For each parameter to be determined, determining the iteration matrix corresponding to the parameter to be determined according to the multiple parameter values ​​to be determined includes determining the iteration matrix according to the following formula (2): Among them, x0… n-1 Refers to the value of each parameter to be determined, f0… n-1 Refers to multiple target nonlinear equations corresponding to each parameter value to be determined, and J refers to the iteration matrix corresponding to each parameter to be determined.

8. The method for determining the energy pipeline inventory of a natural gas pipeline network according to claim 6, characterized in that: For each iterative calculation, determining the iterative increment corresponding to the iterative calculation according to the iterative matrix, the number of iterations corresponding to the iterative calculation and the multiple target nonlinear equations includes determining the iterative increment according to the following formula (3): J k δX k =f(X k ) (3) Among them, k refers to the number of iterations calculated in each iteration, J k refers to the iteration matrix corresponding to the kth iteration calculation, X refers to the parameter value of each parameter to be calculated corresponding to each pipeline section of natural gas, δX k It refers to the iteration increment corresponding to the iterative calculation, f(X k ) refers to the multiple non-target nonlinear equations corresponding to the k-th iteration calculation.

9. The method for determining the energy pipeline inventory of a natural gas pipeline network according to claim 1, characterized in that: For each pipe section of each pipeline, the multiple nonlinear equations are rewritten according to the two position points of the pipe section to obtain a target nonlinear equation corresponding to each nonlinear equation, and the multiple target nonlinear equations include the following formulas (4)(5)(6)(7)(8): Where t refers to the time, i refers to the i-th position point of each pipeline, and i+1 refers to the next position point of each pipeline adjacent to the i-th position point. It refers to the density of natural gas at the i-th point in each pipeline at time t. It refers to the flow rate of natural gas at the i-th position in each pipeline at time t, Δt refers to the time step of setting calculation, and Δx refers to the spatial step of each pipe section. It refers to the pressure of natural gas at the i-th point in each pipeline at time t; It refers to the enthalpy of natural gas at the i-th position of each pipeline at time t. It refers to the mole fraction of gas component n at the i-th position in each pipeline at time t, g refers to the acceleration of gravity, θ refers to the pipeline inclination of each pipeline, λ refers to the actual roughness of each pipeline, D is the diameter of each pipeline, T0 refers to the ambient temperature, K refers to the comprehensive heat transfer coefficient, and Z refers to the compression factor.

10. The method for determining the energy pipeline inventory of a natural gas pipeline network according to claim 1, characterized in that: The physical property parameters include the first temperature and the second temperature, and the first pressure and the second pressure of the natural gas at two position points in each pipe section, respectively. The energy pipe inventory of the natural gas in each pipe section is determined according to the physical property parameters: For each pipe section, determining an average temperature of the pipe section according to the first temperature and the second temperature; For each pipe section, determining an average pressure of the pipe section according to the first pressure and the second pressure; For each pipe segment, determining a first pipe storage of the pipe segment according to the average temperature and the average pressure; For each pipeline, determining a second pipeline inventory of the pipeline according to the first pipeline inventory of all pipeline sections; For each pipeline, the energy inventory of the pipeline is determined according to the second inventory.

11. The method for determining the energy pipeline inventory of a natural gas pipeline network according to claim 10, characterized in that: The physical property parameters also include the mole fraction of each gas component of the natural gas in each pipe section. For each pipeline, determining the energy pipeline inventory of the pipeline according to the second pipeline inventory includes: For each pipe section, determine the actual high molar calorific value of natural gas in the pipe section according to all mole fractions, and use the actual high molar calorific value of the pipe section as the actual high molar calorific value of natural gas in the pipeline corresponding to the pipe section; For each pipeline, the energy pipeline inventory of the natural gas in the pipeline is determined according to the actual high-order molar calorific value and the second pipeline inventory.

12. A processor, characterized in that: The method is configured to execute the method for determining the energy pipeline inventory of a natural gas pipeline network according to any one of claims 1 to 11.

13. A machine-readable storage medium having instructions stored thereon, characterized in that: When the instruction is executed by a processor, the processor is configured to execute the method for determining the energy pipeline inventory of a natural gas pipeline network according to any one of claims 1 to 11.

Images