A method and system for solving the problem of detecting gas source shortage in urban gas pipe network

Abstract

The application discloses a method for solving the problem of insufficient gas source in urban gas pipeline network detection, and belongs to the technical field of gas pipeline network detection; the method comprises the following steps: acquiring pipeline information of a pipeline to be detected; calculating total gas amount provided by all gas sources according to a detector operation control target speed and the pipeline information; obtaining total gas amount required by internal detection operation according to the pipeline information; calculating a total gas amount gap required by the pipeline to be detected according to the total gas amount provided by all gas sources and the total gas amount required by internal detection operation, and obtaining a system for solving the problem of insufficient gas source in urban gas pipeline network detection; and calculating an average gas storage pressure of an upstream pipeline section before internal detection according to the total gas amount gap required by the pipeline to be detected and the pipeline information. The application provides a solution for urban gas pipeline internal detection, and the upstream pipeline of the pipeline to be detected is lifted to a target pressure through gas source storage in advance, so that internal detection operation can be completed in the urban pipeline network with insufficient gas transmission amount.

Description

A method and system for solving the problem of insufficient gas supply in urban gas pipeline networks Technical Field

[0001] This invention relates to the field of gas pipeline network detection technology, specifically to a method and system for solving the problem of insufficient gas supply in urban gas pipeline networks. Background Technology

[0002] Pipeline inspection involves using gas flow within the pipeline to propel a detector within the inspected section, allowing the detector to record corrosion and deformation conditions in real time via sensors. The key to this operation is ensuring the detector maintains a constant speed and reaches its destination within a specified timeframe. Currently, the primary method involves ensuring the detector's operating speed through prolonged gas flow.

[0003] Urban gas operation is affected by a variety of factors such as seasonal temperature differences, morning and evening peak and valley times, and industrial users' production cycles. The monthly and daily gas consumption distribution is extremely uneven. How to ensure the stability of gas flow rate in pipelines is an important consideration for urban gas pipeline inspection operations.

[0004] The key to internal pipeline inspection in urban areas is solving the problem of how to complete the inspection work when the gas supply in the pipeline network is insufficient. Taking advantage of the multiple gas sources in urban gas pipeline networks, the pipeline to be inspected is divided into sections according to gas source nodes, and the gas supply gap for each section is calculated independently, thereby estimating the total gas supply gap for the internal inspection operation. By pre-stocking gas sources and increasing the upstream pipeline of the section to be inspected to the target pressure, internal inspection work can be completed in urban pipeline networks with insufficient gas supply.

[0005] Currently, pipeline inspection technology is mostly used in long-distance oil and gas pipelines, and its application in urban gas pipeline networks presents several challenges. This is due to the unique characteristics of urban gas pipeline networks compared to long-distance oil and gas pipelines: First, urban gas pipeline networks are often ring-shaped or network-like structures with multiple gas source and supply points, resulting in complex and variable gas flow directions within the network. Second, the gas delivery capacity of urban gas pipeline networks is generally smaller than that of long-distance oil and gas pipelines, and is significantly affected by downstream user gas consumption, leading to a large hourly unevenness coefficient in the gas supply load and making it difficult to provide a stable delivery volume. These issues necessitate the use of different control methods for pipeline inspection in urban gas pipeline networks compared to long-distance oil and gas pipelines.

[0006] Internal pipeline inspection is an important means of guiding proper pipeline maintenance and carrying out pipeline integrity management. However, due to the aforementioned issues, internal inspections are rarely conducted on urban gas pipelines.

[0007] Domestic research on pipeline internal inspection mainly focuses on internal inspection technology, inspection methods, and pipeline problem repair. However, in actual internal inspection operations, the airflow environment inside the pipeline is more important, as it controls the speed at which the detector travels within the pipe and directly determines the success or failure of the internal inspection operation. For city gas companies, insufficient gas supply makes it difficult to complete pipeline internal inspection operations normally, posing certain safety risks. Summary of the Invention

[0008] The purpose of this invention is to provide an efficient method and system for solving the problem of insufficient gas supply during testing in urban gas pipeline networks.

[0009] To address the aforementioned technical problems, this invention provides a method for resolving insufficient gas supply detection within urban gas pipeline networks, comprising the following steps:

[0010] Obtain pipeline information for the pipeline to be inspected;

[0011] Based on the detector's operating control target speed v and pipeline information, the total gas volume Q that all gas sources can provide is calculated. n总 The total gas volume Q required for internal testing operations n需 ;

[0012] Based on the total gas volume Q provided by all gas sources n总 The total gas volume Q required for internal testing operations n需 The total gas volume gap Q required for the pipeline to be inspected is calculated. 缺 ;

[0013] Based on the total gas volume gap Q required for the pipeline to be inspected 缺 Based on pipeline information, the average gas storage pressure P of the upstream pipeline section before internal inspection was calculated. 储初 .

[0014] Preferably, the pipeline information includes the pressure P1 at one end of the pipeline to be tested by valve O, and the pressure P at one end of the upstream pipeline by valve O. r The pressure P at the end of the pipeline to be tested z Upstream pipeline starting pressure P0, upstream pipeline total gas transmission capacity Q0, critical gas source Q n Critical Mileage n represents the total number of other gas sources in the pipeline to be tested, L i Let F be the mileage and the cross-sectional area of ​​the pipe.

[0015] Preferably, the total gas volume Q that all gas sources can provide is... n总 The calculation formula is:

[0016]

[0017]

[0018] Where: Q1, Q2...Q n-1 Other gas sources for the pipeline to be tested, t i For time.

[0019] Preferably, the total gas volume Q required for the internal detection operation is... n需 The calculation formula is:

[0020]

[0021] In the formula: P 后 The average pressure after the detector.

[0022] Preferably, the average pressure P after the detector 后 The calculation formula is:

[0023]

[0024] Among them, the detector back-end pressure P 推 The calculation formula is:

[0025]

[0026] In the formula: L 推 This represents the distance the detector travels.

[0027] Preferably, the total gas volume gap Q required for the pipeline to be tested 缺 The calculation formula is:

[0028] Q 缺 =Q n需 -Q n总 .

[0029] Preferably, the average gas storage pressure P of the upstream pipeline section before the internal detection is... 储初 The calculation formula is:

[0030]

[0031]

[0032] In the formula: P 0末 P r末 P represents the pressure at the beginning and end of the upstream gas storage pipeline when the detector reaches the critical point. 储初 Before internal inspection, the upstream gas storage pipeline needs to be raised to the average gas storage pressure; V is the gas volume of the pipeline section to be inspected; T n P is the temperature threshold; nAbsolute pressure threshold; T is the average temperature of the gas, in K; Z 初 Z represents the gas compressibility coefficient of the upstream gas storage pipeline before internal testing. 末 P represents the gas compressibility coefficient in the upstream gas storage section pipeline after the detector reaches the critical point. 储末 This refers to the average absolute pressure of the gas in the upstream gas storage section pipeline after the detector reaches the critical point.

[0033] Preferably, when the detector reaches the critical point, the pressure P at the starting point of the upstream gas storage section pipeline... 0末 The calculation formula is:

[0034]

[0035] Among them, the required gas delivery volume Q for the detector is... 推 The calculation formula is as follows:

[0036] Q 推 =10000F·P 后 ·v

[0037] In the formula: Q 推 The required gas delivery volume for the detector; F is the cross-sectional area of ​​the pipe's inner diameter; P 后 The average pressure after the detector; v is the detector's operating speed; L 储 This refers to the mileage of the gas storage pipeline upstream of the pipeline to be tested.

[0038] The present invention also provides a system for solving the problem of insufficient gas supply in urban gas pipeline networks, comprising:

[0039] The acquisition module is used to acquire pipeline information of the pipeline to be inspected;

[0040] The gas volume calculation module is used to calculate the total gas volume Q that all gas sources can provide based on the detector's operating control target speed v and pipeline information. n总 The total gas volume Q required for internal testing operations n需 ;

[0041] The gap calculation module is used to calculate the total gas volume Q that can be provided by all gas sources. n总 The total gas volume Q required for internal testing operations n需 The total gas volume gap Q required for the pipeline to be inspected is calculated. 缺 ;

[0042] The upstream pipeline gas storage average pressure calculation module before internal inspection is used to calculate the total gas volume gap Q required by the pipeline to be inspected. 缺 Based on pipeline information, the average gas storage pressure P of the upstream pipeline section before internal inspection was calculated. 储初 .

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0044] This invention utilizes the multi-source nature of urban gas pipelines to propose a solution for ensuring stable gas supply during upstream advance gas storage and testing. This invention provides a solution for internal testing of urban gas pipelines: by pre-storing gas sources and increasing the upstream pipeline of the section to be tested to the target pressure, internal testing can be completed in urban pipeline networks where insufficient gas supply exists. Attached Figure Description

[0045] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0046] Figure 1 is a schematic diagram of the structure of the pipeline to be inspected and the upstream pipeline;

[0047] Figure 2 is a schematic diagram showing that the pipeline under test and the upstream pipeline are under pressure.

[0048] Figure 3 is a schematic diagram of the structure of the pipeline to be tested and the upstream pipeline in Example 1;

[0049] Figure 4 is a flowchart illustrating a method for solving the problem of insufficient gas supply in urban gas pipeline networks according to the present invention. Detailed Implementation

[0050] Numerous specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0051] The terminology used in one or more embodiments of this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the one or more embodiments of this specification. The singular forms “a,” “described,” and “the” as used in one or more embodiments of this specification and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in one or more embodiments of this specification refers to and includes any or all possible combinations of one or more associated listed items.

[0052] It should be understood that although the terms first, second, etc., may be used to describe various information in one or more embodiments of this specification, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first may also be referred to as second without departing from the scope of one or more embodiments of this specification, and similarly, second may also be referred to as first. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination."

[0053] The present invention will now be described in further detail with reference to the accompanying drawings:

[0054] Example 1: A method for solving the problem of insufficient gas supply in urban gas pipeline networks, comprising the following steps:

[0055] Step 1: The pipeline to be tested is connected to the upstream pipeline through valve O. The pressures at both ends of valve O are P1 and P2, respectively. r The pressure at the end of the pipeline to be tested is P. z The starting pressure of the upstream pipeline is P0, and the total gas transmission volume of the upstream pipeline is marked as Q0. Other gas sources in the pipeline to be tested are marked as Q1, Q2, ... Q according to the direction of the detector's operation. n ,in and 推 Q n The gas source is called the critical gas source. The pipeline to be tested is divided into sections according to the gas source access point, namely L0, L1, L2, ... L... n Arrive at Q n Gas source access point mileage This is called the critical mileage. The time taken for each detector segment is denoted as t0, t1, t2, ..., t. n The cross-sectional area of ​​the pipe is F. (See Figure 1.)

[0056] During internal detection, the opening of control valve O is kept stable by P1. When the detector reaches the critical point, P... 1初 =P 1末 Internal inspection operations require controlling the inflow to equal outflow in the inspection section of the pipeline. Therefore, the pressure in the inspection section of the pipeline should remain stable before and after the inspection process, i.e., the pressure P at both ends of the inspection section of the pipeline should be constant. z P1 and P1 remain essentially unchanged.

[0057] Step 2: The detector can be considered a point mass when it is running in the pipeline to be tested. Ignoring the throttling effect caused by the detector, the pressure P at the downstream end of the detector... 推 :

[0058]

[0059] In the formula:

[0060] L 推 —The distance the detector travels;

[0061] Step 3: Average pressure P after detector 后 The calculation formula is as follows:

[0062]

[0063] ​When the detector is activated, it is at its starting position P. 推 =P 1初 =P 后 During internal testing, the pressure of P1 is kept constant by controlling the opening degree of valve O.

[0064] Step 4: Based on the pipe's inner diameter, cross-sectional area F, and the average pressure P after the detector... 后 And the detector's operating control target speed v, and the required gas delivery volume Q for the detector's push-bulb operation. 推 .

[0065] Q 推 =10000F·P 后 ·v

[0066] In the formula:

[0067] Q 推 —Gas flow rate (ρ0=0.101325MPa, T0=293.15K), in cubic meters per hour (m³ / h) 3 / h);

[0068] F – Cross-sectional area of ​​the pipe's inner diameter, measured in square meters (m²). 2 );

[0069] P 后 — Average pressure after the detector, in megapascals (MPa);

[0070] v — detector operating speed, in kilometers per hour (km / h).

[0071] Step 5: The detector reaches the critical gas source Q n Critical Mileage At this time, valve O is fully open, ignoring the valve's throttling effect, and the terrain along the pipeline is flat. At this point, P... 1末 =P r末

[0072]

[0073] In the formula: L 储 The mileage of the upstream gas storage pipeline of the pipeline to be tested;

[0074] Step 6: Reaching the critical mileage At that time, the total gas volume that all gas sources can provide is Q. n总 and time t i .

[0075]

[0076]

[0077] Step 7: Reaching the critical mileage At that time, the total gas volume Q required for internal testing operations n需 .

[0078]

[0079] Step 8: Total gas volume gap Q required for the pipeline to be tested 缺

[0080] Q 缺 =Q n需 -Q n总

[0081] Step 9: Mileage L of the gas storage pipeline upstream of the pipeline to be tested 储 The average pressure of the gas storage pipeline must be P 储末 The average gas storage pressure P in the upstream pipeline section before internal testing was increased. 储初 The gas compressibility factor did not change significantly before and after the test, and can be considered as Z. 末 =Z 初 .

[0082]

[0083]

[0084] In the formula:

[0085] P 0末 P r末 —The pressure at the beginning and end of the upstream gas storage pipeline when the detector reaches the critical point.

[0086] P 储初 Before internal testing, the upstream gas storage pipeline needs to be raised to the average gas storage pressure.

[0087] Q 缺 —The total gas volume gap required for the pipeline to be inspected;

[0088] V – Gas volume of the pipe section to be tested, in cubic meters (m³) 3 ;

[0089] T n —293.15K;

[0090] P n —0.101325MPa;

[0091] T – the average temperature of the gas, measured in K.

[0092] Z初 —The gas compressibility coefficient of the upstream gas storage pipeline before internal testing;

[0093] Z 末 —After the detector reaches the critical point, the gas compressibility coefficient of the upstream gas storage section pipeline;

[0094] P 储末 —After the detector reaches the critical point, the average absolute pressure of the gas in the upstream gas storage section pipeline.

[0095] Currently, domestic research on pipeline internal inspection mainly focuses on internal inspection technology, inspection methods, pipeline problem repair, and operational safety. However, in actual internal inspection operations, the airflow environment inside the pipeline is more crucial, as it controls the speed at which the detector travels within the pipe, directly determining the success or failure of the internal inspection operation. For city gas companies, insufficient gas supply makes it difficult to complete pipeline internal inspection operations normally, posing certain safety risks. This invention utilizes the multi-source nature of city gas pipelines to propose a solution for stable gas supply during upstream advance gas storage and inspection, and provides a calculation algorithm, verifying the algorithm's feasibility through examples.

[0096] As shown in Figure 2, before the internal detection, the upstream gas storage pressure is P. 0初 Inlet valve pressure P r初 During the test, as the detector was continuously pushed forward, the pressure decreased. At the end of the test, the upstream gas storage pressure was P. 0末 The pressure at the intake valve port is P. r末 In practical applications, the average upstream gas storage pressure P is calculated using the above parameters and a formula. 储末 The pressure is used to deduce the upstream gas storage pressure and the required gas gap before the internal test.

[0097] To better illustrate the technical effects of the present invention, the present invention provides the following specific embodiments to illustrate the above technical process:

[0098] Example 1: A method for solving the problem of insufficient gas supply in urban gas pipeline networks:

[0099] As shown in Figure 3, P is the first part of the pipe with a diameter of 813 mm before inspection. 1初 =2.91MPa, P z初 =2.86MPa, pipeline compressibility factor 0.93, temperature 20℃. L0 = 3km, L1 = 5km, L2 = 4km, L3 = 8km, L 储 =20km, with point Q3 being the critical mileage, Q0=80000, Q1=20000, Q2=20000, Q3=10000, according to the calculation steps above:

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106] Q 缺 =180343.62-135555.56=44788.07m 3

[0107]

[0108]

[0109] The final result of this internal testing indicates that the required upstream gas storage capacity is 44788.07 m³. 3 The upstream pipeline section needs to be upgraded to a pressure of 3.1443 MPa.

[0110] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules, units, or units is merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units, modules, or components may be combined or integrated into another device, or some features may be ignored or not executed.

[0111] The units may or may not be physically separate. The components shown as units can be one or more physical units, meaning they can be located in one place or distributed in multiple different locations. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0112] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0113] In particular, according to embodiments disclosed in this invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication component, and / or installed from a removable medium. When the computer program is executed by a central processing unit (CPU), it performs the functions defined in the methods of this invention. It should be noted that the computer-readable medium described above in this invention can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof.

[0114] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0115] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for solving the problem of insufficient gas supply in urban gas pipeline networks, characterized in that, Includes the following steps: Obtain pipeline information for the pipeline to be inspected; Based on the detector's operating control target speed and pipeline information, the total gas volume that all gas sources can provide is calculated. Total gas volume required for internal testing operations Based on the total gas volume that all gas sources can provide. Total gas volume required for internal testing operations The total gas volume gap required for the pipeline to be inspected is calculated. Based on the total gas volume gap required for the pipeline to be tested. Based on pipeline information, the average gas storage pressure of the upstream pipeline section before internal inspection was calculated. The pipeline information includes the pressure of valve O at one end of the pipeline to be tested. The pressure at one end of the upstream pipeline of valve O Pressure at the end of the pipeline to be tested upstream pipeline starting pressure Total gas transmission volume of upstream pipelines Critical gas source Critical Mileage , where n represents the total number of other gas sources in the pipeline to be tested. Mileage; mean pressure after detector The calculation formula is: Among them, the pressure at the back end of the detector The calculation formula is: In the formula: The distance the detector travels; the total gas volume gap required for the pipeline to be detected. The calculation formula is: The average gas storage pressure of the upstream pipeline section before the internal detection. The calculation formula is: In the formula: 、 The pressure at the beginning and end of the upstream gas storage section pipeline when the detector reaches the critical point; Before internal testing, the upstream gas storage pipeline needs to be raised to the average gas storage pressure; The gas volume of the pipe section to be tested; Temperature threshold; Absolute pressure threshold; The average temperature of the gas is expressed in Kelvin (K). The compressibility coefficient of the gas in the upstream gas storage section pipeline before internal testing; The gas compressibility coefficient of the upstream gas storage section pipeline after the detector reaches the critical point; The average absolute pressure of the gas in the upstream gas storage section pipeline after the detector reaches the critical point; the pressure at the starting point of the upstream gas storage section pipeline when the detector reaches the critical point. The calculation formula is: Among them, the required gas delivery volume for the detector is... The calculation formula is as follows: In the formula: The required gas delivery volume for the detector; This refers to the cross-sectional area of ​​the pipe's inner diameter. The average pressure after the detector; For detector operating speed; This refers to the mileage of the gas storage pipeline upstream of the pipeline to be tested.

2. The method for solving the problem of insufficient gas supply in urban gas pipeline networks according to claim 1, characterized in that: The total gas volume provided by all gas sources The calculation formula is: In the formula: 、 …… Other gas sources in the pipeline to be tested For time.

3. The method for solving the problem of insufficient gas supply in urban gas pipeline networks according to claim 1, characterized in that: The total gas volume required for the internal testing operation The calculation formula is: In the formula: The average pressure after the detector.

4. A system for solving the problem of insufficient gas supply in urban gas pipeline networks, used to implement the method for solving the problem of insufficient gas supply in urban gas pipeline networks as described in any one of claims 1-3, characterized in that, include: The acquisition module is used to acquire pipeline information of the pipeline to be inspected; The gas volume calculation module is used to calculate the total gas volume that all gas sources can provide based on the detector's operating control target speed and pipeline information. Total gas volume required for internal testing operations ； The gap calculation module is used to calculate the total gas volume that can be provided by all gas sources. Total gas volume required for internal testing operations The total gas volume gap required for the pipeline to be inspected is calculated. The upstream pipeline gas storage average pressure calculation module before internal inspection is used to calculate the total gas volume gap required for the pipeline to be inspected. Based on pipeline information, the average gas storage pressure of the upstream pipeline section before internal inspection was calculated. 。

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