Pipeline air column transient flow simulation method and system

Abstract

The invention discloses a pipeline air column transient flow simulation method and system, and relates to the technical field of numerical simulation calculation, and the method comprises the steps: carrying out the equal interval division of a target pipeline according to a predetermined interval, and constructing a pipeline model of a plurality of nodes; different states of fluid in the pipeline are distinguished, and flow and pressure of pipeline nodes under different conditions are calculated through a control algorithm to predict behaviors of the fluid in the pipeline; and analyzing and calculating pipeline target data in future set time according to the constructed pipeline model and fluid behaviors in the pipeline, and performing pipeline gas column transient flow simulation. According to the method, the transient flow problem of the pipeline gas column can be well simulated by considering the gas thermodynamic characteristics, the precision of numerical simulation can be improved by combining a gas thermodynamic characteristic mechanism, possible engineering hidden dangers can be predicted and pre-judged in advance in an engineering design stage, and the safety of engineering design of a water delivery system is improved.

Description

Technical Field

[0001] The invention relates to the technical field of numerical simulation calculation, and in particular to a pipeline gas column transient flow simulation method and system. Background Art

[0002] As an important component of hydropower stations, long-distance water diversion projects, and urban water supply and drainage systems, water pipelines play a vital role in ensuring the effective transportation of water resources. With the acceleration of modern industry and urbanization, the complexity and scale of water pipeline systems are also increasing. In order to ensure the safe operation of these systems, the dynamic characteristics of the fluid inside the pipeline have become one of the research focuses. Especially in the case of high-pressure water transmission systems, transient flow phenomena inside the pipeline, such as water hammer effect and air column fluctuations, pose a serious threat to the safety of the pipeline structure. At present, the research on air columns in water pipelines mainly focuses on steady-state conditions, while the in-depth discussion of the influence of air columns under transient flow conditions and their interaction with the liquid in the pipeline is still insufficient. Although some studies have attempted to predict the influence of air columns on pipelines through numerical simulation, most methods simplify the thermodynamic characteristics of air columns and ignore factors such as gas compressibility and temperature changes, which to some extent limits the accuracy of the simulation results.

[0003] In the design and operation of existing water pipeline systems, the existence of air columns and the problems they may cause are often underestimated or ignored. For example, when transient flow occurs inside the pipeline, such as when a valve is quickly closed, the air column in the pipeline will be severely compressed or expanded, resulting in a complex wave effect, which may not only lead to the occurrence of water hammer, but also cause damage or even rupture of the pipeline structure due to the instability of the air column. In addition, the numerical simulation of air columns in the prior art usually adopts a simplified model, ignoring the changes in the thermodynamic properties of the gas, especially the effect of temperature changes on the pressure and volume of the air column. Although this simplified treatment simplifies the calculation process, it may lead to significant errors in actual engineering applications, affecting the accuracy of pipeline safety assessments. Therefore, it is particularly important to develop a method that can more accurately simulate the transient flow behavior of pipeline air columns. Summary of the invention

[0004] In view of the problems existing in the existing pipeline gas column transient flow simulation method, the present invention is proposed. Therefore, the problem to be solved by the present invention is how to provide a pipeline gas column transient flow simulation method and system.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides a method for simulating transient flow of an air column in a pipeline, which comprises dividing a target pipeline into multiple nodes at equal intervals according to a predetermined interval; distinguishing different states of the fluid in the pipeline, and calculating the flow and pressure of pipeline nodes under different conditions through a control algorithm to predict the behavior of the fluid in the pipeline; and calculating the pipeline target data within a set future time based on the constructed pipeline model and the analysis of the behavior of the fluid in the pipeline to simulate the transient flow of the air column in the pipeline.

[0007] As a preferred solution of the pipeline gas column transient flow simulation method described in the present invention, the construction of a pipeline model with multiple nodes includes the following steps: selecting a set spacing based on historical experience, measuring and confirming the total length of the target pipeline, and calculating the total number of nodes based on the total length of the pipeline and the selected spacing; setting nodes at set intervals along the pipeline direction starting from one end of the pipeline to determine the specific position of each node in the pipeline, and recording the position coordinates of each node; setting the initial pressure and flow rate of each node according to actual conditions or initial conditions, and assigning a number or label to each node; confirming the data record integrity of all nodes, using known test cases or field data to verify the accuracy of the model and adjust the model parameters.

[0008] As a preferred scheme of the pipeline gas column transient flow simulation method described in the present invention, wherein: the control algorithm includes a pipe flow liquid control algorithm, a gas column control algorithm and a gas-liquid boundary control algorithm; constructing the pipe flow liquid control algorithm includes the following steps, analyzing the simulation results, evaluating the changing trend of the fluid behavior, and adjusting the control parameters as needed, analyzing the changing laws of the pressure and flow rate of the liquid in the pipeline with time and space to determine the pipe flow liquid control equation; converting the pipe flow liquid control equation into an ordinary differential form, converting it into a moving wave equation, constructing a relationship equation between the liquid-related parameters in the target pipeline, calculating the integral of the pipeline node along the positive and negative moving waves to obtain the pipe flow liquid control algorithm, and calculating the pressure and flow of the liquid part.

[0009] As a preferred scheme of the pipeline gas column transient flow simulation method described in the present invention, the gas column control algorithm includes analyzing the thermodynamic characteristics of the gas column to determine the gas column control algorithm to describe the transient behavior of the gas column, and calculating to determine the pressure and flow of the gas; applying the ideal surface hypothesis at the gas-liquid boundary, combining the results of the liquid control algorithm and the gas control algorithm to determine the change pattern of the gas-liquid boundary position over time, and constructing a gas-liquid boundary control algorithm to comprehensively determine the pressure and flow of the gas-liquid boundary.

[0010] As a preferred scheme of the pipeline gas column transient flow simulation method described in the present invention, wherein: the pipeline target data within a set future time is calculated based on the constructed pipeline model and the analysis of the fluid behavior in the pipeline, including that if there is no air column in any node to be measured of the target pipeline relative to the target pipeline, it indicates that the fluid on the inside of the target pipeline at the node to be measured is liquid, then according to a predetermined pipe flow liquid control algorithm, the pressure and flow of the pipeline nodes adjacent to the node to be measured are calculated to obtain the target flow and target pressure of the node to be measured.

[0011] As a preferred scheme of the pipeline gas column transient flow simulation method described in the present invention, wherein: the calculation of the pipeline target data within the future set time based on the constructed pipeline model and the analysis of the fluid behavior in the pipeline also includes if there is an air column in any node to be measured of the target pipeline relative to the target pipeline, it indicates that there is gas in the node to be measured relative to the target pipeline, then according to the predetermined pipe flow liquid control algorithm, the gas column control algorithm considering the thermodynamic properties of the gas and the gas-liquid boundary control algorithm, the target flow and target pressure of the node to be measured are determined, and the ideal surface assumption is applied at the gas-liquid boundary to determine the gas-liquid boundary position within the future set time, the target flow and target pressure data of any point in the pipeline containing the gas column.

[0012] As a preferred scheme of the pipeline gas column transient flow simulation method described in the present invention, the pipeline gas column transient flow simulation includes the following steps: obtaining the simulation initial conditions and the pipeline model, initializing the simulation time step and the total simulation time; calculating the pressure and flow of the fluid in the pipeline according to the state of the fluid in the pipeline, starting a cyclic simulation, checking whether each node in the pipeline contains an air column, and selecting a control algorithm for calculation and simulation according to whether there is an air column at the node in the pipeline; updating the status information of all nodes, calculating the fluid pressure and flow of the node in the pipeline at the next time step, increasing the time counter count, and judging whether the end time of the simulation has been reached. If the end time of the simulation has been reached, the pipeline gas column transient flow simulation is completed and the simulation results are output; recording the data of each time step obtained by the simulation, drawing the pressure and flow change curves with time, and analyzing the simulation results by the change trajectory of the gas-liquid boundary position.

[0013] In the second aspect, the present invention provides a pipeline gas column transient flow simulation system, which includes: a construction module, which is used to divide the target pipeline into multiple nodes at equal intervals according to a predetermined interval; a calculation module, which is used to distinguish different states of the fluid in the pipeline, and calculate the pipeline node flow and pressure under different conditions through a control algorithm to predict the fluid behavior in the pipeline; an analysis module, which calculates the pipeline target data within a set future time based on the constructed pipeline model and the fluid behavior in the pipeline, and performs pipeline gas column transient flow simulation.

[0014] In a third aspect, the present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, wherein: when the processor executes the computer program, the steps of the pipeline air column transient flow simulation method are implemented.

[0015] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, the steps of a method for simulating transient flow of a pipeline gas column are implemented.

[0016] The beneficial effect of the present invention is that by considering the thermodynamic characteristics of gas, the transient flow problem of pipeline gas column can be better simulated in terms of pressure peak, fluctuation period, pressure decay, etc. It can combine the mechanism of gas thermodynamic characteristics to improve the accuracy of numerical simulation, help predict and prejudge possible engineering hazards in advance during the engineering design stage, and improve the safety of water delivery system engineering design. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 This is a flow chart of the simulation method for transient flow of air column in pipeline.

[0019] Figure 2 Schematic diagram of pipeline node division.

[0020] Figure 3 This is a comparison chart of the gas column pressure fluctuation curves under working condition 1.

[0021] Figure 4 This is a comparison chart of the gas column pressure fluctuation curve under working condition 2. DETAILED DESCRIPTION

[0022] In order to make the above-mentioned purposes, features and advantages of the present invention more understandable, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0023] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0024] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0025] Example 1

[0026] Reference Figure 1 , which is the first embodiment of the present invention, provides a pipeline gas column transient flow simulation method, comprising:

[0027] S1: Divide the target pipeline into equal intervals according to the predetermined intervals to build a pipeline model with multiple nodes;

[0028] The target pipeline is divided into N-1 segments according to the preset equal spacing Δx, each segment contains a node, thus forming N pipeline nodes. This step ensures that the fluid in the pipeline can be accurately modeled.

[0029] Divide the target pipeline into equally spaced partitions according to the predetermined spacing Δx. Ensure that each partition contains the first and last nodes to form a complete pipeline model. Initialize the relevant parameters of each node, such as position, initial pressure, and flow rate.

[0030] Choose an appropriate spacing Δx according to the research requirements. Generally speaking, the smaller the spacing, the more sophisticated the model, but the more computational effort. You can refer to the experience of previous similar studies or determine the size of Δx based on theoretical analysis.

[0031] Measure or confirm the total length L of the target pipeline. If the actual length of the target pipeline is known, use this value directly. If it is unknown, obtain it through field measurement or by consulting the design drawings.

[0032] According to the total length of the pipeline L and the selected spacing Δx, the total number of nodes N required is calculated using the following formula:

[0033]

[0034] Where N is the total number of nodes in the pipeline, Indicates rounding up; L is the total length of the target pipeline;

[0035] Determine the specific location of each node in the pipeline, starting from one end of the pipeline, and set a node every Δx along the pipeline direction. Record the location coordinates of each node, usually the distance from the starting point of the pipeline to the node. Make sure the last node is at the other end of the pipeline.

[0036] The initial pressure H and flow rate V of each node are set according to the actual situation or initial conditions. These initial values ​​can be set based on the operating conditions of the pipeline or other known information.

[0037] Assign a unique number or label to each node. This helps to accurately identify each node in subsequent calculations and data analysis.

[0038] Further refine the model details based on the specific application scenario and computing needs. If necessary, add additional details near specific nodes, such as the location of valves, pumps, or other equipment. Confirm that the data records of all nodes are complete and correct. Validate the model before formal use to ensure its accuracy and reliability. Use known test cases or field data to verify the accuracy of the model. Adjust the model parameters until satisfactory accuracy is achieved.

[0039] S2: Distinguish different states of the fluid in the pipeline, and predict the behavior of the fluid in the pipeline by calculating the flow and pressure of the pipeline nodes under different conditions through the control algorithm;

[0040] Analyze the simulation results, evaluate the changing trend of fluid behavior, and adjust the control parameters as needed. Analyze the changing rules of the pressure and flow rate of the liquid in the pipeline with time and space to determine the pipe flow liquid control equation. The calculation formula is:

[0041]

[0042] Among them, H is the pressure of the target pipeline, V is the liquid flow rate, c is the speed of pipe flow wave propagation, g is the gravity acceleration, D is the pipe diameter, and f is the pipeline friction coefficient;

[0043] The pipe flow liquid control equation is converted into ordinary differential form, and its moving wave equation is expressed as:

[0044]

[0045] The pipe flow liquid control equation is converted into a moving wave equation, and the relationship equation between the parameters related to the liquid in the target pipe is constructed. The pipe flow liquid control algorithm is obtained by calculating the integrals of the pipeline nodes along the positive and negative moving waves, and the pressure and flow of the liquid part are calculated. The calculation formula is:

[0046] H P+ =H A +XQ A -(X+Y|Q A |)QP

[0047] H P- =H B -XQ B +(X+Y|Q B |)Q P

[0048]

[0049] Δx=cΔt

[0050] Among them, X and Y are constants, H A is the liquid pressure at the pipeline node A, H B is the liquid pressure at pipeline node B, Q A is the liquid flow rate at pipeline node A, Q B is the liquid flow rate at pipeline node B, H p is the target pressure of the node P to be tested, Q P is the liquid flow of the node P to be measured, pipeline node A and pipeline node B are pipeline nodes adjacent to the node P to be measured; A is the cross-sectional area of ​​the target pipeline, and Δx is the spacing between the pipeline nodes of the target pipeline.

[0051] The thermodynamic characteristics of the gas column are analyzed to determine the gas column control algorithm to describe the transient behavior of the gas column, and the pressure and flow rate of the gas are calculated and determined. The expression is:

[0052]

[0053] Among them, H a is the absolute pressure of the gas column in the target pipeline, C p is the constant pressure specific heat capacity of the gas column, C v is the constant volume specific heat capacity of the gas column, V a is the volume of the gas column in the pipe, ɑ is the thermodynamic coefficient of the gas column, A a is the total contact area between the gas column and the tube wall, T in is the target pipe internal temperature, T ex is the external environment temperature;

[0054] The ideal surface assumption is applied at the gas-liquid boundary, and the results of the liquid control algorithm and the gas control algorithm are combined to determine the change law of the gas-liquid boundary position over time. The gas-liquid boundary control algorithm is constructed to comprehensively determine the pressure and flow rate of the gas-liquid boundary, which is expressed as:

[0055]

[0056] H wa =H a

[0057] Among them, x wis the target distance between the gas-liquid boundary position and the upstream node at time t+△t, x w0 is the distance between the gas-liquid boundary position and the most upstream node at time t, v c is the liquid velocity at time t, H wa is the liquid pressure at time t.

[0058] If there is no air column in any node to be tested of the target pipeline relative to the target pipeline, it means that the fluid in the node to be tested relative to the inner side of the target pipeline is liquid. Then, according to the predetermined pipe flow liquid control algorithm, the pressure and flow of the pipeline node adjacent to the node to be tested are calculated to obtain the target flow and target pressure of the node to be tested. The calculation formula is:

[0059]

[0060] A1=H A +XQ A ;

[0061] B1=H B -XQ B ;

[0062] A2=X+Y|Q A |;

[0063] B2=X+Y|Q B |;

[0064] Among them, A1 is the first characteristic parameter of pipeline node A, B1 is the first characteristic parameter of pipeline node B; A2 is the second characteristic parameter of pipeline node A, and B2 is the second characteristic parameter of pipeline node B.

[0065] Ideal surface hypothesis: In order to avoid the tediousness and complexity of the liquid model when tracing the gas-liquid boundary, the following assumption will be introduced, that is, the mechanical inertia of the thin layer of water column ΔLwi near the gas-liquid boundary is ignored, that is, the thin layer of water column is regarded as an inelastic liquid, which is called the "ideal surface" hypothesis.

[0066] Transient flow is the transition process of unstable flow state when water flow changes from one stable state to another stable state.

[0067] If there is a gas column in any node to be measured of the target pipeline relative to the target pipeline, it indicates that there is gas in the node to be measured relative to the target pipeline. Then, according to the predetermined pipe flow liquid control algorithm, the gas column control algorithm considering the thermodynamic characteristics of the gas, and the gas-liquid boundary control algorithm, the target flow and target pressure of the node to be measured are determined. The ideal surface assumption is applied at the gas-liquid boundary to determine the gas-liquid boundary position within the future set time, the target flow and target pressure data of any point in the pipeline containing the gas column, and the expression is:

[0068] HP’ =H a

[0069] Q P’ =Q a

[0070] Among them, H a is the gas pressure at time t+△t; Q a is the gas flow rate at time t+△t, H P’ is the pressure at the gas-liquid boundary at time t+△t, Q P’ It is the flow rate at the gas-liquid boundary at time t+△t.

[0071] S3: Calculate the pipeline target data within a set time in the future based on the constructed pipeline model and the fluid behavior analysis in the pipeline, and perform transient flow simulation of the pipeline gas column.

[0072] Get the simulation initial conditions and pipeline model, initialize the simulation time step and the total simulation time;

[0073] The pressure and flow rate of the fluid in the pipeline are calculated according to the state of the fluid in the pipeline, and the cyclic simulation is started. For each node in the pipeline, it is checked whether there is an air column. According to whether there is an air column at the node in the pipeline, the control algorithm is selected for calculation and simulation;

[0074] Update the status information of all nodes, calculate the node fluid pressure and flow rate in the pipeline at the next time step, and increase the time counter count to determine whether the simulation end time has been reached. If the simulation end time has been reached, the pipeline gas column transient flow simulation is completed and the simulation results are output;

[0075] Record the data of each time step obtained from the simulation, draw the curves of pressure and flow rate changing with time, and analyze the simulation results by the changing trajectory of the gas-liquid boundary position.

[0076] Furthermore, the present embodiment also provides a pipeline air column transient flow simulation system, including: a construction module, used to divide the target pipeline into multiple nodes at equal intervals according to a predetermined interval; a calculation module, used to distinguish different states of the fluid in the pipeline, and calculate the pipeline node flow and pressure under different conditions through a control algorithm to predict the fluid behavior in the pipeline; an analysis module, which calculates the pipeline target data within a set future time based on the constructed pipeline model and the fluid behavior in the pipeline, and performs pipeline air column transient flow simulation.

[0077] This embodiment also provides a computer device, which is suitable for the case of a pipeline gas column transient flow simulation method, including: a memory and a processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement all or part of the steps of the method described in the embodiment of the present invention as proposed in the above embodiment.

[0078] This embodiment also provides a storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the method in any optional implementation of the above embodiment is executed. Wherein, the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (Static Random Access Memory, referred to as SRAM), electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, referred to as EEPROM), erasable programmable read-only memory (Erasable Programmable Read-Only Memory, referred to as EPROM), programmable read-only memory (Programmable Red-Only Memory, referred to as PROM), read-only memory (Read-Only Memory, referred to as ROM), magnetic memory, flash memory, disk or optical disk.

[0079] The storage medium proposed in this embodiment and the data storage method proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be found in the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0080] From the above, it can be seen that this method can better simulate the transient flow problem of pipeline gas column in terms of pressure peak, fluctuation period, pressure decay, etc. by considering the thermodynamic characteristics of gas. It can improve the accuracy of numerical simulation by combining the mechanism of gas thermodynamic characteristics, help predict and prejudge possible engineering hazards in advance during the engineering design stage, and improve the safety of water supply system engineering design.

[0081] Example 2

[0082] Reference Figure 3 and Figure 4 , which is the second embodiment of the present invention, and this embodiment provides a method for simulating transient flow of a pipeline gas column. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0083] The experimental horizontal pipe length is 8.382m, the vertical pipe length is 0.48m, the inner diameter is 0.040m, the average resistance coefficient of the target pipe is 0.090, and the measured pipe flow wave velocity is 850m / s. Two sets of working conditions with different boundary conditions are used for model verification.

[0084] In working condition 1, the upstream of the target pipeline is set as the pressure inlet boundary (pressure tank), the pressure is 0.08MPa, and the length of the gas column in the initial pipeline is controlled to be 0.3m. At the beginning of the experiment, the ball valve is opened instantaneously, the pipeline begins to fill, and the liquid impacts the gas column in the vertical pipeline, causing transient changes. The pressure fluctuation comparison curve of the gas column at the end of the pipeline is obtained by Figure 3 It can be seen that the fluctuation trend, cycle and pressure peak of the gas column pressure change curve at the end of the pipeline can be well predicted.

[0085] In working condition 2, the upstream of the target pipeline is set as the pressure inlet boundary, the pressure is 0.12MPa, and the length of the gas column in the initial pipeline is controlled to be 0.3m. At the beginning of the experiment, the ball valve is opened instantaneously, the pipeline begins to fill, and the liquid impacts the gas column in the vertical pipeline, causing a transient change. Figure 4 It can be seen that the fluctuation trend, cycle and pressure peak of the gas column pressure change curve at the end of the pipeline can be well predicted.

[0086] Table 1 Test data table

[0087] Serial number Test conditions Simulation accuracy (%) Run time (seconds) Average error (kPa) 1 Benchmarks 95.2 24.3 1.4 2 High pressure conditions 94.6 25.6 1.6 3 Low pressure conditions 96.3 23.1 1.2 4 Large diameter pipe 95.8 24.9 1.4 5 Small diameter tube 96.1 24.5 1.3 8 Multiple gas columns 94.9 25.9 1.6 9 Single gas column 96.2 23.3 1.2

[0088] From the above, it can be seen that this method can better simulate the transient flow problem of pipeline gas column in terms of pressure peak, fluctuation period, pressure decay, etc. by considering the thermodynamic characteristics of gas. It can improve the accuracy of numerical simulation by combining the mechanism of gas thermodynamic characteristics, help predict and prejudge possible engineering hazards in advance during the engineering design stage, and improve the safety of water supply system engineering design.

[0089] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for simulating transient flow of pipeline gas column, characterized by: include, The target pipeline is divided into equal intervals according to a predetermined interval to construct a pipeline model with multiple nodes; Distinguish the different states of the fluid in the pipeline, and predict the behavior of the fluid in the pipeline by calculating the pipeline node flow and pressure under different conditions through the control algorithm; Based on the constructed pipeline model and the analysis of the fluid behavior in the pipeline, the pipeline target data within the future set time is calculated and the transient flow simulation of the pipeline gas column is carried out.

2. The pipeline gas column transient flow simulation method according to claim 1, characterized in that: The pipeline model of building multiple nodes includes the following steps: Select the set spacing based on historical experience, measure and confirm the total length of the target pipeline, and calculate the total number of nodes based on the total length of the pipeline and the selected spacing; Starting from one end of the pipeline, nodes are set at set intervals along the pipeline direction to determine the specific position of each node in the pipeline, and the position coordinates of each node are recorded; Set the initial pressure and flow rate of each node according to the actual situation or initial conditions, and assign a number or label to each node; Confirm data record integrity for all nodes, validate model accuracy using known test cases or field data, and adjust model parameters.

3. The pipeline gas column transient flow simulation method according to claim 2, characterized in that: The control algorithm includes a pipe flow liquid control algorithm, a gas column control algorithm and a gas-liquid boundary control algorithm; The construction of pipe flow liquid control algorithm includes the following steps: analyzing simulation results, evaluating the changing trend of fluid behavior, adjusting control parameters as needed, analyzing the changing rules of pressure and flow rate of the liquid in the pipeline with time and space to determine the pipe flow liquid control equation; The pipe flow liquid control equation is converted into ordinary differential form and then into a moving wave equation. The relationship equation between the parameters related to the liquid in the target pipeline is constructed. The integral of the pipeline node along the positive and negative moving waves is calculated to obtain the pipe flow liquid control algorithm, and the pressure and flow of the liquid part are calculated.

4. The pipeline gas column transient flow simulation method according to claim 3, characterized in that: The gas column control algorithm includes analyzing the thermodynamic characteristics of the gas column to determine the gas column control algorithm describes the transient behavior of the gas column, and calculating and determining the pressure and flow of the gas; The ideal surface assumption is applied at the gas-liquid boundary, and the results of the liquid control algorithm and the gas control algorithm are combined to determine the change pattern of the gas-liquid boundary position over time. A gas-liquid boundary control algorithm is constructed to comprehensively determine the pressure and flow rate of the gas-liquid boundary.

5. The pipeline gas column transient flow simulation method according to claim 4, characterized in that: The pipeline target data within a set future time period is calculated based on the constructed pipeline model and the analysis of the fluid behavior in the pipeline. If there is no air column in any node to be measured of the target pipeline relative to the target pipeline, it indicates that the fluid inside the node to be measured relative to the target pipeline is liquid. Then, according to a predetermined pipe flow liquid control algorithm, the pressure and flow of the pipeline node adjacent to the node to be measured are calculated to obtain the target flow and target pressure of the node to be measured.

6. The pipeline gas column transient flow simulation method according to claim 5, characterized in that: The calculation of pipeline target data within a future set time based on the constructed pipeline model and the analysis of the fluid behavior in the pipeline also includes: if there is an air column in any node to be measured of the target pipeline relative to the target pipeline, it indicates that there is gas in the node to be measured relative to the target pipeline, then according to the predetermined pipe flow liquid control algorithm, the gas column control algorithm considering the thermodynamic characteristics of the gas, and the gas-liquid boundary control algorithm, the target flow and target pressure of the node to be measured are determined, and the ideal surface assumption is applied at the gas-liquid boundary to determine the gas-liquid boundary position within the future set time, the target flow and target pressure data of any point in the pipeline containing the gas column.

7. The pipeline gas column transient flow simulation method according to claim 6, characterized in that: The pipeline gas column transient flow simulation comprises the following steps: Get the simulation initial conditions and pipeline model, initialize the simulation time step and the total simulation time; The pressure and flow rate of the fluid in the pipeline are calculated according to the state of the fluid in the pipeline, and the cyclic simulation is started. For each node in the pipeline, it is checked whether there is an air column. According to whether there is an air column at the node in the pipeline, the control algorithm is selected for calculation and simulation; Update the status information of all nodes, calculate the node fluid pressure and flow rate in the pipeline at the next time step, and increase the time counter count to determine whether the simulation end time has been reached. If the simulation end time has been reached, the pipeline gas column transient flow simulation is completed and the simulation results are output; Record the data of each time step obtained from the simulation, draw the curves of pressure and flow rate changing with time, and analyze the simulation results by the changing trajectory of the gas-liquid boundary position.

8. A pipeline air column transient flow simulation system, based on the pipeline air column transient flow simulation method according to any one of claims 1 to 7, characterized in that: include, A construction module, used for dividing the target pipeline into equal intervals according to a predetermined interval to construct a pipeline model of multiple nodes; The calculation module is used to distinguish different states of the fluid in the pipeline and predict the behavior of the fluid in the pipeline by calculating the flow and pressure of the pipeline nodes under different conditions through the control algorithm; The analysis module calculates the pipeline target data within a set time in the future based on the constructed pipeline model and the fluid behavior analysis in the pipeline, and performs transient flow simulation of the pipeline gas column.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the pipeline air column transient flow simulation method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the pipeline air column transient flow simulation method according to any one of claims 1 to 7 are implemented.

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