Natural gas long-distance pipeline network flow calculation and voting method and system

Abstract

The present invention provides a method and system for calculating and voting the flow rate of a long-distance natural gas pipeline network, including: step 1: establishing a network topology map; step 2: setting the fluid input and output direction and flow rate data of each node and pipe section, the diameter, mileage and elevation information of each pipe section, and accessing the network topology map to generate a digitized topological model of the network; step 3: performing distributed calculation of the overall flow rate of the network; step 4: setting a voting mechanism for automatically allocating and triggering the flow rate calculation of each distributed node according to the hydraulic characteristics of different nodes and pipe sections, and triggering the voting mechanism when the results of different flow calculations are different according to the steady-state and dynamic characteristics of different algorithms; step 5: regularly checking the balance of the accumulated flow rate of the flow calculation results. The present invention grasps the real-time flow distribution of a complex network system through the hardware characteristics of existing network equipment, and provides an extremely important data basis for network energy consumption evaluation and network command and dispatch.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid simulation for long-distance natural gas transmission pipeline networks, and in particular to a method and system for calculating and voting flow rates in long-distance natural gas pipeline networks. Background Art

[0002] The long-distance natural gas pipeline network usually has a long total mileage, a large number of stations and downstream users, a variety of core energy-consuming equipment, and complex and changeable pipeline operation and scheduling plans. The accuracy of pipeline energy consumption optimization and evaluation lies in the real-time calculation of the dynamic flow of the pipeline network because there is no effective metering of pipeline trunk lines and branches. The calculation of pipeline flow should comprehensively consider factors such as pipeline operation condition data, metering data, pipeline flow characteristics, and equipment thermal balance characteristics:

[0003] 1. Data cleaning: The distributed computing model that traffic calculation relies on and the association model between each node require a large amount of real-time online data. Before data is collected and applied, data cleaning is required, and methods such as breakpoint data processing, extreme value processing, anomaly identification, automatic assignment, and noise processing should be fully considered.

[0004] 2. The input variables of the movement flow back-calculation model are the compressor inlet and outlet process conditions, operating parameters, natural gas physical properties and inherent movement data. The inherent movement data requires reliability judgment of the original movement test data. For movements that have not been factory tested, the movement design parameters can be used.

[0005] 3. The pipe resistance-flow model should be divided into sections, and the conformity of various classic pipe resistance models such as Weymouth, Panhandle A Formula, ModifiedPanhandle B Formula, AGAEquations, etc. with the actual situation should be evaluated.

[0006] 3. Use operating data to calibrate compressor inlet flowmeter, intraocular pressure difference and other devices with metering properties as auxiliary flow measurement.

[0007] 4. The flow balance model relies on the standard volume flow of a large number of flow meters for fractional user metering and internal and external transfer point metering flow meters, combined with the real-time turnover change value of the pipeline section.

[0008] 5. Since the distributed calculation model of pipeline flow involves many station nodes and the process data of pipeline sections is huge, the accuracy of data processing and the real-time calculation efficiency must be guaranteed.

[0009] At present, the algorithm flow calculation and voting mechanism of natural gas long-distance pipeline network is basically as follows: Figure 1 shown.

[0010] Patent document CN113239645A discloses a system and method for dynamic tracking and real-time calculation of natural gas components in a natural gas pipeline network, which includes: a data acquisition and monitoring system, an intermediate production database interface machine, an online chromatographic analyzer and an online transient simulation software server; the data acquisition and monitoring system is used to obtain real-time data from the on-site SCADA server interface machine of the gas transmission pipeline network control center, and send the obtained real-time data to the online transient simulation software server through the intermediate production database interface machine; the online transient simulation software server synchronously performs real-time hydraulic simulation calculation and natural gas component tracking calculation of pipeline network natural gas flow according to the obtained real-time data, and compares the calculated natural gas component tracking calculation result with the calorific value data fed back by the online chromatographic analyzer, and outputs the natural gas component tracking calculation result when the error is less than a preset threshold. The present invention can be widely used in the field of natural gas component calculation.

[0011] Patent document CN113298293A discloses a natural gas pipeline network transmission path matching method, comprising the following steps: initializing nodes and pipe sections of the natural gas pipeline network, wherein the nodes include root nodes, station nodes and child nodes; performing iterative calculations in the order of natural gas resources in the root nodes from small to large, specifying a root node, determining the child nodes closest to the root node, allocating the natural gas of the root node to the child nodes until the child nodes are saturated, and marking the child nodes; continuing to search for the unmarked child nodes closest to the root node, allocating the natural gas of the root node to the child nodes until the child nodes are saturated and marked, and repeating the operation until the natural gas of the specified root node is allocated; specifying the next root node and repeating the iterative calculations until the natural gas of all root nodes is allocated or all child nodes are marked. The present invention has the effect of more efficiently and reasonably planning and matching the natural gas transmission path.

[0012] Patent document CN113642184A discloses a method for optimizing the operation of natural gas pipelines under the goal of carbon neutrality. From the perspective of energy structure adjustment, it proposes a complete low-carbon and low-consumption optimization model for long-distance natural gas pipelines, which is used to refine the calculation of carbon emissions and energy consumption of multiple energy sources during the transportation of natural gas pipelines; for different energy structure backgrounds, the corresponding minimum carbon emission objective function is established, and the optimization algorithm is used to solve the minimum carbon emission objective function and give the optimal scheduling plan, such as compressor type selection, compressor combination mode, station pressure, and temperature along the line. The present invention can achieve energy conservation and emission reduction in pipeline transportation and provide technical support for the entire natural gas industry.

[0013] Patent document CN113221304A (application number: CN202110614058.5) discloses a calculation method and system for indirect energy assignment of a natural gas pipeline network, which is characterized by including the following contents: 1) obtaining real-time data of pressure, flow and natural gas calorific value parameters of each gas source point and download point of the natural gas pipeline network to be tested; 2) using an energy indirect assignment calculation model to calculate the calorific value parameters of each download point of the natural gas pipeline network to be tested in real time according to the received real-time data; 3) based on whether each download point of the natural gas pipeline network to be tested is equipped with a gas chromatograph, the calorific value of each download point is assigned in real time according to the calorific value parameters calculated in real time.

[0014] However, the above patent is a numerical simulation calculation method for energy consumption assessment, component calculation and transportation scheduling of natural gas pipeline networks. It does not involve the effective calculation of the operating flow of each node within the overall pipeline network, nor does it have a suitable means to verify the overall results and balance correction of the pipeline network. Summary of the invention

[0015] In view of the defects in the prior art, the object of the present invention is to provide a method and system for calculating and voting flow in a long-distance natural gas pipeline network.

[0016] The method for calculating and voting the flow rate of a long-distance natural gas pipeline network provided by the present invention comprises:

[0017] Step 1: Establish a pipeline network topology diagram, including the first station, the last station, the compressor station, the distribution station, the transfer station and the pipe sections between each node, and set the flow boundaries, geographic information and equipment attributes at each location of the topology model;

[0018] Step 2: Set the fluid input flow direction and flow data of each node and pipe segment, the diameter, mileage and elevation information of each pipe segment, and access the pipe network topology map to generate a digital topological model of the pipe network;

[0019] Step 3: Perform distributed calculation of the overall flow of the pipe network;

[0020] Step 4: According to the hydraulic characteristics of different nodes and pipe sections, set up a voting mechanism to automatically allocate and trigger the flow calculation of each distributed node. According to the steady-state and dynamic characteristics of different algorithms, the voting mechanism is triggered when the results of different flow calculations are different;

[0021] Step 5: Regularly check the balance of the accumulated flow rate of the flow calculation results. The formula is:

[0022] ∑Qin+∑Qcons+∑Qvent=∑Qsale+∑ΔQpipe

[0023] Among them, Qin is the upload and transfer volume of all nodes in the target pipeline network, Qcons is the self-consumption of production and life in the pipeline network, Qvent is the natural gas venting volume in the pipeline network, Qsale is the trade sales volume of all nodes, and ΔQpipe is the change in pipeline inventory.

[0024] Preferably, a network information model is established to characterize the interconnection relationship between the trunk lines, branch lines, tributaries and tie lines of the natural gas pipeline network. Based on the network information model, each node and pipe section is assigned with input metering point location and geographic information to generate a set of digitized topological models.

[0025] Construct a real-time flow back calculation model for the compressor unit movement data, a pipeline flow resistance-flow calculation model, a flow calculation model for resistive components, and a pipe storage-flow balance model to perform distributed calculation of the overall flow of the pipeline network, cross-validate the calculation results of the flow at each node, eliminate abnormal points that do not meet the preset conditions, and regularly adjust the pipeline network gas volume balance and pipe storage balance under different assessment windows.

[0026] Preferably, the real-time flow back-calculation model of the compressor unit movement uses the characteristic curve of compressor head-flow-speed-efficiency, calculates the variable head through the compressor inlet and outlet flow, temperature, and components, and calculates the variable head through the natural gas property model and thermodynamic polytropic process, obtains the inlet working flow through the polytropic head and the compressor speed, and further converts it into the inlet standard flow, and the formula is:

[0027]

[0028]

[0029] Qcomp=f(H pl ,ω)

[0030] Where: n is the number of flow segments; Z is the compression factor; P d is the compressor outlet pressure; P s is the compressor inlet pressure; T d is the compressor outlet temperature; T s is the compressor inlet temperature; H pl is the variable head at the compressor outlet; ω is the compressor speed; Qcomp is the compressor inlet operating flow rate.

[0031] Preferably, the pipeline flow resistance-flow calculation model uses the inlet and outlet temperature pressure of the pipe section and the geographical information of the pipe section to directly calculate the flow rate under steady-state conditions, and the formula is:

[0032]

[0033]

[0034]

[0035] Among them, Q 12 represents the flow from node 1 to node 2; C is a constant; D is the inner diameter of the pipeline; d is the relative density of natural gas; T cp is the effective temperature; Zcp is the effective compressibility factor; ε is the pipe roughness; Re is the Reynolds number; λ is the friction coefficient; R is the gas constant; g is the gravity constant; El 12i is the height of the i-th segment among the n segments between node 1 and node 2; L 12i It is the length of the i-th segment among the n segments between node 1 and node 2.

[0036] Preferably, the flow calculation model of the resistive element is realized by using a segmented flow-differential pressure formula: Q=K*(ΔP)^0.5, where K is a correction coefficient and ΔP is the differential pressure of the resistive element;

[0037] The pipe storage-flow balance model performs real-time flow balance for a fixed period based on the recursive method, and the formula is:

[0038] Q i+1 =Q i -∑Qsale+∑Qtransin-∑Qcons+∑ΔQpipe

[0039] Q i+2 =Q i+1 -∑Q i+1 sale+∑Q i+1 transin-∑Q i+1 cons+∑ΔQ i+1 pipe

[0040] Among them, i, i+1, i+2 are node numbers, Qsale is the sales volume, Qtransin is the upload and transfer volume, Qcons is the internal consumption of natural gas, and ΔQpipe is the change in pipeline inventory.

[0041] The natural gas long-distance pipeline network flow calculation and voting system provided by the present invention comprises:

[0042] Module M1: Establish the pipeline network topology diagram, including the first station, the last station, the compressor station, the distribution station, the transfer station and the pipe sections between each node, and set the flow boundary, geographic information and equipment attributes at each location of the topology model;

[0043] Module M2: Set the fluid input flow direction and flow data of each node and pipe segment, the diameter, mileage and elevation information of each pipe segment, and access the pipe network topology map to generate a digital topological model of the pipe network;

[0044] Module M3: Distributed calculation of the overall flow of the pipe network;

[0045] Module M4: According to the hydraulic characteristics of different nodes and pipe sections, a voting mechanism is set to automatically allocate and trigger the flow calculation of each distributed node. According to the steady-state and dynamic characteristics of different algorithms, the voting mechanism is triggered when the results of different flow calculations are different;

[0046] Module M5: Regularly check the balance of the accumulated flow rate of the flow calculation results. The formula is:

[0047] ∑Qin+∑Qcons+∑Qvent=∑Qsale+∑ΔQpipe

[0048] Among them, Qin is the upload and transfer volume of all nodes in the target pipeline network, Qcons is the self-consumption of production and life in the pipeline network, Qvent is the natural gas venting volume in the pipeline network, Qsale is the trade sales volume of all nodes, and ΔQpipe is the change in pipeline inventory.

[0049] Preferably, a network information model is established to characterize the interconnection relationship between the trunk lines, branch lines, tributaries and tie lines of the natural gas pipeline network. Based on the network information model, each node and pipe section is assigned with input metering point location and geographic information to generate a set of digitized topological models.

[0050] Construct a real-time flow back calculation model for the compressor unit movement data, a pipeline flow resistance-flow calculation model, a flow calculation model for resistive components, and a pipe storage-flow balance model to perform distributed calculation of the overall flow of the pipeline network, cross-validate the calculation results of the flow at each node, eliminate abnormal points that do not meet the preset conditions, and regularly adjust the pipeline network gas volume balance and pipe storage balance under different assessment windows.

[0051] Preferably, the real-time flow back-calculation model of the compressor unit movement uses the characteristic curve of compressor head-flow-speed-efficiency, calculates the variable head through the compressor inlet and outlet flow, temperature, and components, and calculates the variable head through the natural gas property model and thermodynamic polytropic process, obtains the inlet working flow through the polytropic head and the compressor speed, and further converts it into the inlet standard flow, and the formula is:

[0052]

[0053]

[0054] Qcomp=f(H pl ,ω)

[0055] Where: n is the number of flow segments; Z is the compression factor; P d is the compressor outlet pressure; P s is the compressor inlet pressure; T d is the compressor outlet temperature; Ts is the compressor inlet temperature; H pl is the variable head at the compressor outlet; ω is the compressor speed; Qcomp is the compressor inlet operating flow rate.

[0056] Preferably, the pipeline flow resistance-flow calculation model uses the inlet and outlet temperature pressure of the pipe section and the geographical information of the pipe section to directly calculate the flow rate under steady-state conditions, and the formula is:

[0057]

[0058]

[0059]

[0060] Among them, Q 12 represents the flow from node 1 to node 2; C is a constant; D is the inner diameter of the pipeline; d is the relative density of natural gas; T cp is the effective temperature; Zcp is the effective compressibility factor; ε is the pipe roughness; Re is the Reynolds number; λ is the friction coefficient; R is the gas constant; g is the gravity constant; El 12i is the height of the i-th segment among the n segments between node 1 and node 2; L 12i It is the length of the i-th segment among the n segments between node 1 and node 2.

[0061] Preferably, the flow calculation model of the resistive element is realized by using a segmented flow-differential pressure formula: Q=K*(ΔP)^0.5, where K is a correction coefficient and ΔP is the differential pressure of the resistive element;

[0062] The pipe storage-flow balance model performs real-time flow balance for a fixed period based on the recursive method, and the formula is:

[0063] Q i+1 =Q i -∑Qsale+∑Qtransin-∑Qcons+∑ΔQpipe

[0064] Q i+2 =Q i+1 -∑Q i+1 sale+∑Q i+1 transin-∑Q i+1 cons+∑ΔQ i+1 pipe

[0065] Among them, i, i+1, i+2 are node numbers, Qsale is the sales volume, Qtransin is the upload and transfer volume, Qcons is the internal consumption of natural gas, and ΔQpipe is the change in pipeline inventory.

[0066] Compared with the prior art, the present invention has the following beneficial effects:

[0067] (1) The present invention designs a comprehensive natural gas pipeline network flow calculation solution, which comprehensively applies multiple technologies such as natural gas physical property calculation, pipeline flow theory, compressor rotating equipment performance calculation and measurement and testing components. Various algorithms complement each other and have high availability.

[0068] (2) By adopting the method of the present invention, it is possible to fully simulate the dynamic characteristics of the entire natural gas pipeline network without adding new large-caliber metering hardware, thereby providing an important data basis for the calculation of natural gas transmission energy consumption indicators, economic evaluation, and command and dispatch;

[0069] (3) The method of the present invention takes into account both the steady-state and dynamic characteristics of pipeline flow, has high calculation efficiency, and a clear voting principle. Pipeline network operators can access parameter configuration and correct the accuracy of the algorithm in a timely manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0071] Figure 1 This is a flow chart of the current natural gas pipeline network flow calculation and voting mechanism algorithm;

[0072] Figure 2 This is a data anomaly recognition and valid data assignment effect diagram involved in this algorithm;

[0073] Figure 3 It is a flow calculation and voting mechanism effect diagram of all nodes of a long-distance pipeline trunk line in the pipeline network at a certain time;

[0074] Figure 4 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0075] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0076] Embodiment 1:

[0077] like Figure 4 According to the method for calculating and voting the flow rate of a long-distance natural gas pipeline network provided by the present invention, the method comprises:

[0078] Step 1: Establish a topological diagram of a complex pipeline network, including the network's first station, terminal station, compressor station, distribution station, transfer station, and pipe sections between nodes, and determine basic data information such as flow boundaries, geographic information, and equipment attributes at each location in the topological model.

[0079] Step 2: Determine the fluid input and output direction and flow data of each node and pipe section, the diameter, mileage and elevation information of each pipe section, and connect this information to the pipe network topology map created in step 1 to generate a digital topological model of the pipe network. This step requires obtaining the design parameters of the pipe network distribution, core equipment, and all flow data of the upstream and downstream of the pipe network, including all links of internal transfer, user distribution, equipment self-consumption, and station venting.

[0080] Step 3: It includes four main flow calculation methods: real-time flow back calculation model of compressor unit movement data, pipeline flow resistance-flow calculation model, flow calculation model of resistive components, and pipe storage-flow balance model, to realize the distributed calculation of the overall flow of the pipeline network. The movement flow back calculation model needs to obtain the real-time process parameters and equipment performance attribute parameters of the equipment, the resistive component flow calculation model needs to obtain the differential pressure and process parameters of the resistive component, the pipe storage-flow balance model needs to obtain the process parameters of the inlet and outlet of each pipe section and the geographical attributes of the pipe section, and the pipe storage-flow balance model needs to obtain all flow parameters.

[0081] Step 4: A voting mechanism is provided to automatically allocate and trigger the flow calculation method of each distributed node according to the hydraulic characteristics of different nodes and pipe sections.

[0082] Step 5: Regularly check the balance of the accumulated flow rate of the flow calculation results and regularly start flow correction.

[0083] The first station, the last station and the node close to the gas delivery flowmeter adopt the recursive method of flowmeter and pipe storage change, and the correction coefficient of other flow is based on the flow of the delivery flowmeter;

[0084] For all compressor station nodes equipped with compressors, the relatively accurate movement data model after flow verification can be used as the distributed flow calculation model for the intermediate key nodes;

[0085] The pipe resistance-flow model has poor dynamics and slightly poor accuracy, but it is easy to implement and can quickly calculate and verify all pipe sections. It is a general algorithm for general nodes.

[0086] A small number of nodes have uncalibrated differential pressure elements and regulating elements that are not used for metering. If their import and export process data can be obtained by the SCADA system, they will also be used for flow calculation purposes.

[0087] After the network topology model is created, the main nodes can use at least two calculation models, and each node has its own voting mechanism prefabricated, including the following principles: preferred flow, excluded flow, median, and average.

[0088] The pipe storage-flow balance model uses the recursive (pipe storage correction) method to compare the flow with the pipe resistance model and the other three schemes of the core characteristics, so as to reduce the parameter uncertainty caused by the change of pipeline working conditions (unsteady) as much as possible. It is recommended to calculate at the minute or hour level, and the grid calculation ensures that the result is as close to the actual working conditions as possible. The flow is compared by using the recursive (pipe storage correction), pipe resistance model, and core characteristics schemes to reduce the parameter uncertainty caused by the change of pipeline working conditions (unsteady) as much as possible. The flow calculation model is calculated at the minute or hour level, and the grid calculation ensures that the result is as close to the actual working conditions as possible. The core data of the unit algorithm model is preferentially selected from the ASME PTC-10 factory test data, and the expected performance data is used when there is no test data. The unit efficiency can be queried through the core data or calculated through the natural gas heat balance. If the difference between the two is not big, the average value is taken; if the difference between the two is large, the program will automatically determine the reasonable efficiency range (60-90%) and automatically eliminate the wrong results. The performance calculation reserves a correction interface to correct the efficiency calculation of long-term abnormalities. Abnormal process data are eliminated by statistical methods of process capability index CPK and threshold over-limit. The voting mechanism is to use flow recursion as much as possible when close to the flow meter side, and use pipe resistance model when far away from the flow meter side; if the model characteristics are accurate, the model characteristics can be used. It is recommended that the calculation step length is once per hour, which can meet the dynamic characteristics of the pipeline and ensure calculation efficiency.

[0089] The natural gas long-distance pipeline network flow calculation and voting system provided by the present invention comprises: module M1: establishing a network topology map, including the network head station, terminal station, compressor station, distribution station, transfer station and pipe sections between each node, setting the flow boundary, geographic information and equipment attributes at each location of the topology model; module M2: setting the fluid input and output flow direction and flow data of each node and pipe section, the diameter, mileage and elevation information of each pipe section, and accessing the network topology map to generate a digitized topology model of the network; module M3: performing distributed calculation of the overall flow of the network; module M4: setting a voting mechanism for automatically allocating and triggering the flow calculation of each distributed node according to the hydraulic characteristics of different nodes and pipe sections, and triggering the voting mechanism when the results of different flow calculations are different according to the steady-state and dynamic characteristics of different algorithms; module M5: regularly checking the balance of the accumulated flow on the flow calculation results, and the formula is:

[0090] ∑Qin+∑Qcons+∑Qvent=∑Qsale+∑ΔQpipe

[0091] Among them, Qin is the upload and transfer volume of all nodes in the target pipeline network, Qcons is the self-consumption of production and life in the pipeline network, Qvent is the natural gas venting volume in the pipeline network, Qsale is the trade sales volume of all nodes, and ΔQpipe is the change in pipeline inventory.

[0092] Establish a network information model that represents the interconnection relationship of various trunk lines, branch lines, tributaries, and connecting lines of the natural gas pipeline network. On the basis of the network information model, assign metering points and geographic information to each node and pipe section to generate a set of data-based topological models; construct a real-time flow inverse calculation model for compressor unit movement data, a pipeline flow resistance-flow calculation model, a flow calculation model for resistive components, and a pipe storage-flow balance model to perform distributed calculation of the overall flow of the pipeline network, cross-validate the calculation results of the flow of each node, eliminate abnormal points that do not meet the preset conditions, and regularly adjust the pipeline network gas volume revenue and expenditure balance and pipe storage balance under different assessment windows.

[0093] The real-time flow back-calculation model of the compressor unit movement uses the characteristic curve of compressor head-flow-speed-efficiency, calculates the variable head through the compressor inlet and outlet flow, temperature, and components, and calculates the inlet working flow through the natural gas property model and thermodynamic polymorphic process. The inlet working flow is obtained through the polymorphic head and the compressor speed, and is further converted into the inlet standard flow. The formula is:

[0094]

[0095]

[0096] Qcomp=f(H pl ,ω)

[0097] Where: n is the number of flow segments; Z is the compression factor; P d is the compressor outlet pressure; P s is the compressor inlet pressure; T d is the compressor outlet temperature; T s is the compressor inlet temperature; H pl is the variable head at the compressor outlet; ω is the compressor speed; Qcomp is the compressor inlet operating flow rate.

[0098] The pipeline flow resistance-flow calculation model uses the inlet and outlet temperature pressure of the pipe section and the geographical information of the pipe section to directly calculate the flow rate under steady-state conditions. The formula is:

[0099]

[0100]

[0101]

[0102] Among them, Q 12 represents the flow from node 1 to node 2; C is a constant; D is the inner diameter of the pipeline; d is the relative density of natural gas; T cp is the effective temperature; Zcp is the effective compressibility factor; ε is the pipe roughness; Re is the Reynolds number; λ is the friction coefficient; R is the gas constant; g is the gravity constant; El 12i is the height of the i-th segment among the n segments between node 1 and node 2; L 12i It is the length of the i-th segment among the n segments between node 1 and node 2.

[0103] The flow calculation model of the resistive element is realized by using a segmented flow-differential pressure formula: Q=K*(ΔP)^0.5, K is a correction coefficient, and ΔP is the differential pressure of the resistive element;

[0104] The pipe storage-flow balance model performs real-time flow balance for a fixed period based on the recursive method, and the formula is:

[0105] Q i+1 =Q i -∑Qsale+∑Qtransin-∑Qcons+∑ΔQpipe

[0106] Q i+2 =Q i+1 -∑Q i+1 sale+∑Q i+1 transin-∑Q i+1 cons+∑ΔQ i+1 pipe

[0107] Among them, i, i+1, i+2 are node numbers, Qsale is the sales volume, Qtransin is the upload and transfer volume, Qcons is the internal consumption of natural gas, and ΔQpipe is the change in pipeline inventory.

[0108] Embodiment 2:

[0109] Embodiment 2 is a preferred example of Embodiment 1.

[0110] like Figures 1 to 3 The domestic natural gas pipeline network has 28 main nodes, 43 core compression equipment, a total length of more than 2,000 kilometers, more than 450 effective flow metering points, 13 transfer points, and 10 connected branch lines and tributaries.

[0111] First, the basic information model of the pipeline network is created, and the 28 main nodes are extracted. The input and output information and location of each main node are entered into the model as dynamic constraints.

[0112] A total of 16 movement data models were created for 43 core compressor devices. It was verified that 10 of the 16 models were relatively accurate, 4 were usable after adjustment, and the remaining 2 model data were unreliable and were not included in the algorithm.

[0113] There are 27 pipe sections between the 28 main nodes. 27 pipe resistance boundary conditions are designed. Five classic pipe resistance model equations are evaluated and two of them are determined as the final models.

[0114] From the SCADA system database of the pipeline network, Figure 1 All types of time series data involved are exported for no less than 2 months for data cleaning and used for training algorithm models.

[0115] according to Figure 1 According to the specified algorithm flow, various algorithms involved in the pipe network topology model are compiled into a big data distributed flow calculation program. One month's data is used to analyze the output results of various flow calculation methods, and a flow voting mechanism and correction algorithm are formulated.

[0116] The algorithm model that integrates the flow calculation model and the voting model is verified on the data of another month. The calculation results are compared with the monthly report statistical results of the pipeline network scheduling statistics. It fully meets the monthly flow-pipeline balance and can provide dynamic and real-time flow distribution data of all nodes in the pipeline network. The algorithm can be run online and can also be analyzed and verified on historical data.

[0117] Those skilled in the art know that, in addition to implementing the system, device and its various modules provided by the present invention in a purely computer-readable program code, it is entirely possible to implement the same program in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers and embedded microcontrollers by logically programming the method steps. Therefore, the system, device and its various modules provided by the present invention can be considered as a hardware component, and the modules included therein for implementing various programs can also be considered as structures within the hardware component; the modules for implementing various functions can also be considered as both software programs for implementing the method and structures within the hardware component.

[0118] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for calculating and voting flow in a long-distance natural gas pipeline network, characterized in that: include: Step 1: Establish a pipeline network topology diagram, including the first station, the last station, the compressor station, the distribution station, the transfer station and the pipe sections between each node, and set the flow boundaries, geographic information and equipment attributes at each location of the topology model; Step 2: Set the fluid input and output flow direction and flow data of each node and pipe segment, the diameter, mileage and elevation information of each pipe segment, and access the pipe network topology map to generate a digital topological model of the pipe network; Step 3: Construct the real-time flow back-calculation model of the compressor unit movement, the pipeline flow resistance-flow calculation model, the flow calculation model of the resistive element, and the pipe storage-flow balance model to perform distributed calculation of the overall flow of the pipeline network; The real-time flow back-calculation model of the compressor unit movement uses the characteristic curve of compressor head-flow-speed-efficiency, calculates the variable head through the compressor inlet and outlet flow, temperature, and components, and through the natural gas property model and thermodynamic polytropic process, obtains the inlet working flow through the polytropic head and the compressor speed, and converts it into the inlet standard flow; The pipeline flow resistance-flow calculation model uses the inlet and outlet temperature pressure of the pipeline section and the geographical information of the pipeline section to directly calculate the flow rate under steady-state conditions; The flow calculation model of the resistive element is realized by segmented flow-differential pressure; The pipe storage-flow balance model performs real-time flow balance for a fixed period based on a recursive method; Step 4: According to the hydraulic characteristics of different nodes and pipe sections, set up a voting mechanism to automatically allocate and trigger the flow calculation of each distributed node. According to the steady-state and dynamic characteristics of different algorithms, the voting mechanism is triggered when the results of different flow calculations are different; Step 5: Regularly check the balance of the accumulated flow rate of the flow calculation results. The formula is: ∑Qin+∑Qcons+∑Qvent=∑Qsale+∑ΔQpipe Among them, Qin is the upload and transfer volume of all nodes in the target pipeline network, Qcons is the self-consumption of production and life in the pipeline network, Qvent is the natural gas venting volume in the pipeline network, Qsale is the trade sales volume of all nodes, and ΔQpipe is the change in pipeline inventory.

2. The method for calculating and voting flow rate of a long-distance natural gas pipeline network according to claim 1 is characterized in that: Establish a network information model that represents the interconnection relationship between the trunk lines, branch lines, tributaries, and tie lines of the natural gas pipeline network. On the basis of the network information model, assign the metering point and geographic information to each node and pipe section to generate a set of digital topological models. The calculation results of the flow at each node are cross-validated, and abnormal points that do not meet the preset conditions are eliminated. The gas revenue and expenditure balance and pipeline storage balance under different assessment windows are regularly adjusted.

3. The method for calculating and voting the flow rate of a long-distance natural gas pipeline network according to claim 2 is characterized in that: The formula of the real-time flow back-calculation model of the compressor unit movement is: Qcomp=f(H pl ,ω) Where: n is the number of flow segments; Z is the compression factor; P d is the compressor outlet pressure; P s is the compressor inlet pressure; T d is the compressor outlet temperature; T s is the compressor inlet temperature; H pl is the variable head at the compressor outlet; ω is the compressor speed; Qcomp is the compressor inlet operating flow rate.

4. The method for calculating and voting flow rate of a long-distance natural gas pipeline network according to claim 3 is characterized in that: The formula of the pipeline flow resistance-flow calculation model is: Among them, Q 12 represents the flow from node 1 to node 2; C is a constant; D is the inner diameter of the pipeline; d is the relative density of natural gas; T cp is the effective temperature; Zcp is the effective compressibility factor; ε is the pipe roughness; Re is the Reynolds number; λ is the friction coefficient; R is the gas constant; g is the gravity constant; El 12i is the height of the i-th segment among the n segments between node 1 and node 2; L 12i It is the length of the i-th segment among the n segments between node 1 and node 2.

5. The method for calculating and voting flow rate of a long-distance natural gas pipeline network according to claim 4 is characterized in that: The flow calculation model of the resistive element is: Q = K*(ΔP)^0.5, K is the correction coefficient, ΔP is the differential pressure of the resistive element; The formula of the pipe storage-flow balance model is: Q i+1 =Q i -∑Qsale+∑Qtransin-∑Qcons+∑ΔQpipe Q i+2 =Q i+1 -∑Q i+1 sale+∑Q i+1 transin-∑Q i+1 cons+∑ΔQ i+1 pipe Among them, i, i+1, i+2 are node numbers, Qsale is the sales volume, Qtransin is the upload and transfer volume, Qcons is the internal consumption of natural gas, and ΔQpipe is the change in pipeline inventory.

6. A natural gas long-distance pipeline network flow calculation and voting system, characterized in that: include: Module M1: Establish the pipeline network topology diagram, including the first station, the last station, the compressor station, the distribution station, the transfer station and the pipe sections between each node, and set the flow boundary, geographic information and equipment attributes at each location of the topology model; Module M2: Set the fluid input and output flow direction and flow data of each node and pipe segment, the diameter, mileage and elevation information of each pipe segment, and access the pipe network topology map to generate a digital topological model of the pipe network; Module M3: Construct the real-time flow back-calculation model of the compressor unit movement, the pipeline flow resistance-flow calculation model, the flow calculation model of the resistive element, and the pipe storage-flow balance model to perform distributed calculation of the overall flow of the pipeline network; The real-time flow back-calculation model of the compressor unit movement uses the characteristic curve of compressor head-flow-speed-efficiency, calculates the variable head through the compressor inlet and outlet flow, temperature, and components, and through the natural gas property model and thermodynamic polytropic process, obtains the inlet working flow through the polytropic head and the compressor speed, and converts it into the inlet standard flow; The pipeline flow resistance-flow calculation model uses the inlet and outlet temperature pressure of the pipeline section and the geographical information of the pipeline section to directly calculate the flow rate under steady-state conditions; The flow calculation model of the resistive element is realized by segmented flow-differential pressure; The pipe storage-flow balance model performs real-time flow balance for a fixed period based on a recursive method; Module M4: According to the hydraulic characteristics of different nodes and pipe sections, a voting mechanism is set to automatically allocate and trigger the flow calculation of each distributed node. According to the steady-state and dynamic characteristics of different algorithms, the voting mechanism is triggered when the results of different flow calculations are different; Module M5: Regularly check the balance of the accumulated flow rate of the flow calculation results. The formula is: ∑Qin+∑Qcons+∑Qvent=∑Qsale+∑ΔQpipe Among them, Qin is the upload and transfer volume of all nodes in the target pipeline network, Qcons is the self-consumption of production and life in the pipeline network, Qvent is the natural gas venting volume in the pipeline network, Qsale is the trade sales volume of all nodes, and ΔQpipe is the change in pipeline inventory.

7. The natural gas long-distance pipeline network flow calculation and voting system according to claim 6 is characterized in that: Establish a network information model that represents the interconnection relationship between the trunk lines, branch lines, tributaries, and tie lines of the natural gas pipeline network. On the basis of the network information model, assign the metering point and geographic information to each node and pipe section to generate a set of digital topological models. The calculation results of the flow at each node are cross-validated, and abnormal points that do not meet the preset conditions are eliminated. The gas revenue and expenditure balance and pipeline storage balance under different assessment windows are regularly adjusted.

8. The natural gas long-distance pipeline network flow calculation and voting system according to claim 7 is characterized in that: The formula of the real-time flow back-calculation model of the compressor unit movement is: Qcomp=f(H pl ,ω) Where: n is the number of flow segments; Z is the compression factor; P d is the compressor outlet pressure; P s is the compressor inlet pressure; T d is the compressor outlet temperature; T s is the compressor inlet temperature; H pl is the variable head at the compressor outlet; ω is the compressor speed; Qcomp is the compressor inlet operating flow rate.

9. The natural gas long-distance pipeline network flow calculation and voting system according to claim 8 is characterized in that: The formula of the pipeline flow resistance-flow calculation model is: Among them, Q 12 represents the flow from node 1 to node 2; C is a constant; D is the inner diameter of the pipeline; d is the relative density of natural gas; T cp is the effective temperature; Zcp is the effective compressibility factor; ε is the pipe roughness; Re is the Reynolds number; λ is the friction coefficient; R is the gas constant; g is the gravity constant; El 12i is the height of the i-th segment among the n segments between node 1 and node 2; L 12i It is the length of the i-th segment among the n segments between node 1 and node 2.

10. The natural gas long-distance pipeline network flow calculation and voting system according to claim 9, characterized in that: The flow calculation model of the resistive element is: Q = K*(ΔP)^0.5, K is the correction coefficient, ΔP is the differential pressure of the resistive element; The formula of the pipe storage-flow balance model is: Q i+1 =Q i -∑Qsale+∑Qtransin-∑Qcons+∑ΔQpipe Q i+2 =Q i+1 -∑Q i+1 sale+∑Q i+1 transin-∑Q i+1 cons+∑ΔQ i+1 pipe Among them, i, i+1, i+2 are node numbers, Qsale is the sales volume, Qtransin is the upload and transfer volume, Qcons is the internal consumption of natural gas, and ΔQpipe is the change in pipeline inventory.

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