A method for dynamic simulation of gas pipe network based on pressure sampling data

Abstract

The application provides a method for simulating a gas pipe network dynamically based on pressure sampling data, medium pressure sensors and atmospheric pressure sensors are installed near each source point, sink point and node of a city pipe network to monitor the medium absolute pressure and atmospheric pressure of each point in real time, the mutual relationship between the absolute pressures of each point in a static state is obtained through an iterative algorithm, so that the influence of factors such as the elevation and pressure sensor measurement error on the calculation result is eliminated. The application solves the technical problems that the existing simulation calculation method of the gas pipe network cannot accurately grasp the gas flow information of the pipe network, the abnormal gas flow condition cannot be found in time, and logical errors in the pipe network cannot be found in time. The application can be widely applied in the field of dynamic monitoring of the gas pipe network.

Description

Technical Field

[0001] This invention relates to a method for dynamic monitoring of gas pipeline networks, and more particularly to a method for dynamic simulation of gas pipeline networks based on pressure sampling data. Background Technology

[0002] Gas mainly refers to natural gas. As a low-consumption, high-return, low-pollution, and high-efficiency smokeless industry and strategic industry, natural gas is of great strategic importance to the national economy and sustainable development. Transporting natural gas to households through gas pipelines, and monitoring the pressure and flow of the gas pipeline network in real time during the transportation process, are essential means to eliminate potential safety hazards.

[0003] With the popularization and development of IoT technology, dynamic monitoring methods for urban pipeline networks are gradually maturing. However, existing gas pipeline network simulation calculation methods cannot accurately grasp gas flow information, are slow to detect abnormal gas flow rates, and cannot promptly identify logical errors in the pipeline network. Summary of the Invention

[0004] This invention addresses the technical problems of existing gas pipeline monitoring methods, such as difficulty in accurately grasping gas flow information in the pipeline network, untimely detection of abnormal gas flow rates, and inability to detect logical errors in the pipeline network in a timely manner. It provides a method for dynamic simulation of gas pipeline networks based on pressure sampling data, which can obtain gas flow information in the pipeline network in real time, monitor abnormal gas flow, and clarify the logical relationships of the pipeline network.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: a method for dynamic simulation of gas pipeline networks based on pressure sampling data, characterized in that a medium pressure sensor and an atmospheric pressure sensor are installed near each source point, sink point, and node of the urban gas municipal pipeline network. The medium pressure sensor is used to monitor the absolute pressure of the medium at each point in real time, and the atmospheric pressure sensor is used to monitor the atmospheric pressure at each point in real time. The static absolute pressure difference at each point is obtained through an iterative algorithm, and the flow velocity, flow direction, flow rate, and gas consumption information of the gas in the pipeline are obtained through hydraulic calculation formulas.

[0006] Preferably, the specific steps for obtaining the static absolute pressure difference at each point using an iterative algorithm are as follows:

[0007] Step 1: Let the source point be set {A}. Find the point with the highest gas supply pressure in set {A} and set it as A0. Let the other elements in set {A} be (Ai). Let the node be set {B} and any element in set {B} be (Bi). Let the sink point be set {C} and any element in set {C} be (Ci).

[0008] Step 2: Collect 24-hour data from each measuring point daily, find the absolute pressure of the medium when the local gauge pressure is at its maximum, and set it as P. 绝 Record the P 绝 At the corresponding time point, read the absolute pressure value of point A0 as P0, and calculate P. 绝 -P0 is marked as the daily static absolute pressure difference of the measuring point. It is calculated every day, and the minimum absolute value is retained. After iterating for a period of time, the static absolute pressure difference of all measuring points relative to point A0 is determined, and the positive and negative signs are retained.

[0009] Step 3, obtain the set of static absolute pressure differences at all source points {P} Ai静}, the set of static absolute pressure differences of all nodes {P Bi静}, the set of static absolute pressure differences at all sinks {P Ci静}

[0010] Preferably, taking any node Bi as the center, let the connected pipe segment be Gi, where i is an integer, and its adjacent points be points of any nature such as source point, node, and sink point. Based on the static absolute pressure difference between each point and point A0, the static absolute pressure value between point Bi and all surrounding adjacent points is calculated.

[0011] Preferably, the method for obtaining the flow direction of gas in the pipeline is as follows: Let the static absolute pressure difference between Bi and a certain adjacent point be ΔPi. 静态 Let the corresponding pipe section be Gi, and let the absolute pressure at point Bi measured at a certain moment be P. Bi测 The measured absolute pressure value at a certain adjacent point is P. 邻测 When P 邻测 -P Bi测 -△Pi 静态 When P is greater than 0, the medium flow direction in pipe segment Gi is from the adjacent point to point Bi. 邻测 -P Bi测 -△Pi 静态 When P is less than 0, the medium flow direction in pipe segment Gi is from point Bi to the adjacent point; when P... 邻测 -P Bi测 -△Pi 静态 When the value approaches 0, the medium in pipe segment Gi does not flow.

[0012] Preferably, let △Pi 动态 =P 邻测 -P Bi测 -△Pi 静态 When △Pi 动态 When p > 0, the medium flows from the adjacent point to point Bi, then p i =P Bi测 p j =P Bi测 -△Pi 动态 When △Pi 动态<When p is 0, the medium flows from point Bi to the adjacent point, then p j =P Bi测 p i =P Bi测 +△Pi 动态 Where pi is the absolute pressure at the inlet node of the pipe segment, and pj is the absolute pressure at the outlet node of the pipe segment.

[0013] The preferred hydraulic calculation formula for high- and medium-pressure gas pipeline sections is:

[0014]

[0015]

[0016] In the formula:

[0017] p i p j —Absolute pressure at the inlet and outlet nodes of the pipe section, in kPa;

[0018] L—Length of the pipe section, in km;

[0019] λ—the coefficient of frictional resistance of the pipe section;

[0020] q k —Gas flow rate under standard conditions, in meters 3 / h;

[0021] d—Inner diameter of the pipe section, mm;

[0022] ρ — density of the gas, kg / m³ 3 The value is 0.7174 at 0℃ and 101.325 kPa.

[0023] T—Temperature of the gas, unit: K, T=T0+t℃, where t is the temperature of the medium;

[0024] Z—Gas compressibility factor, which is set to 1 when the gas pressure is less than 1.2 MPa;

[0025] T0—Gas temperature under standard conditions, unit: K, take T0 = 273.16 K;

[0026] K—Equivalent absolute roughness of the inner surface of the pipe section;

[0027] Re – Reynolds number.

[0028] The beneficial effects of this invention are:

[0029] (1) By measuring the pressure at each point, the gas flow information of the pipeline network can be obtained in real time, the gas flow direction can be grasped, the medium flow rate can be obtained by calculation, and abnormal gas flow and sudden large leakage events can be monitored.

[0030] (2) Be able to understand the logical relationships of the pipeline network and promptly identify logical errors;

[0031] (3) It can promptly identify bottleneck pipe sections, provide design basis for pipeline construction, and provide data support for gas network allocation and visual management. Detailed Implementation

[0032] The present invention will be further described below with reference to embodiments thereof.

[0033] A method for dynamic simulation of gas pipeline networks based on pressure sampling data is proposed. This method involves installing medium pressure sensors and atmospheric pressure sensors near various source points, sink points, and nodes of the urban gas municipal pipeline network to monitor the absolute pressure of the medium and atmospheric pressure at each point in real time. An iterative algorithm is used to obtain the relationship between the absolute pressures at each point in a static state, thereby eliminating the influence of factors such as elevation and pressure sensor measurement errors on the calculation results. The specific steps are as follows:

[0034] Step 1: Let the source point be set {A}. Find the point with the highest gas supply pressure in set {A} and set it as A0. Let the elements of the other points be (Ai). Let the node be set {B} and let any element be (Bi). Let the sink point be set {C} and let any element be (Ci).

[0035] Step 2: Collect 24-hour data from each measuring point and find the local gauge pressure (P). 绝 -P a The absolute pressure of the medium at its maximum (when local fluidity is at its minimum) is denoted as P. 绝 Record the P 绝 At the corresponding time point, read the absolute pressure value of point A0 as P0, and calculate P. 绝 -P0 is marked as the daily static absolute pressure difference of the measuring point. It is calculated every day, and the minimum absolute value is retained. After iterating for a period of time, such as 30 days, the static absolute pressure difference of all measuring points relative to point A0 is determined, and the positive and negative signs are retained.

[0036] Step 3, obtain {P} of all source points Ai静}, the {P} of all nodes Bi静}, all sinks {P Ci静 Taking any node Bi as the center, let the connected pipe segment be Gi (i = 1, 2, 3...), and its adjacent points be points of any nature such as source point, node, sink point, etc. Based on the static absolute pressure difference between each point and A0, calculate the static absolute pressure between point Bi and all its surrounding adjacent points.

[0037] Let the static absolute pressure difference between Bi and a certain adjacent point be ΔPi. 静态 Let the corresponding pipe section be Gi, and let the absolute pressure at point Bi measured at a certain moment be P.Bi测 The measured absolute pressure value at a certain adjacent point is P. 邻测 , such as P 邻测 -P Bi测 -△Pi 静态 If the value is greater than 0, then the medium flow direction in pipe segment Gi is from the adjacent point to point Bi, such as P. 邻测 -P Bi测 -△Pi 静态 If <0, then the medium flow direction in pipe segment Gi is from point Bi to the adjacent point, such as P. 邻测 -P Bi测 -△Pi 静态 If the value approaches 0, then the medium in pipe segment Gi will not flow. Here, "approaching 0" means equal to or close to 0.

[0038] The collected information is processed, and the flow direction of the medium in the pipe section where the point is located is obtained based on the static absolute pressure difference, absolute pressure value and absolute pressure value of a certain point and the absolute pressure value of adjacent points.

[0039] Let △Pi 动态 =P 邻测 -P Bi测 -△Pi 静态 Determine the import / export relationship between point Bi and its adjacent points (via "P"). 邻测 -P Bi测 -△Pi 静态 The value of "" determines the flow direction, and thus the import / export relationship. Based on the import / export relationship, p is set. i =P Bi测 With p j =P Bi测 -△Pi 动态 , or p j =P Bi测 With p i =P Bi测 +△Pi 动态 The flow velocity, flow direction, flow rate, and gas consumption information of pipe segment Gi are obtained through calculation.

[0040] The hydraulic calculation formulas for high- and medium-pressure gas pipeline sections are as follows:

[0041]

[0042]

[0043] In the formula:

[0044] p i p j —Absolute pressure at the inlet and outlet nodes of the pipe section, in kPa;

[0045] L—Length of the pipe section, in km;

[0046] λ—the coefficient of frictional resistance of the pipe section;

[0047] q k —Gas flow rate under standard conditions, in meters 3 / h;

[0048] d—Inner diameter of the pipe section, mm;

[0049] ρ — density of the gas, kg / m³ 3 (0.7174 at 0℃ and 101.325 kPa);

[0050] T—Temperature of the gas, unit: K, (T=0+t℃), where t is the temperature of the medium;

[0051] Z—Gas compressibility factor (taken as 1 when the gas pressure is less than 1.2 MPa);

[0052] T0—Gas temperature under standard conditions, unit: K, (T0 = 273.16 K);

[0053] K—Equivalent absolute roughness of the inner surface of the pipe section;

[0054] Re – Reynolds number.

[0055] Repeat the above calculations to obtain dynamic flow information for all pipe segments under arbitrary pressure conditions, thereby achieving dynamic simulation of the pipeline network.

[0056] By measuring the pressure at various points, real-time gas flow information in the pipeline network can be obtained, the direction of gas flow can be grasped, the medium flow rate can be obtained through calculation, and abnormal gas flow and sudden large-scale leakage events can be monitored. The logical relationship of the pipeline network can be straightened out and logical errors can be detected in time. Bottleneck pipe sections can be identified in time, providing design basis for pipeline construction and data support for gas network allocation and visualization management.

[0057] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for dynamic simulation of gas pipeline networks based on pressure sampling data, characterized in that, Medium pressure sensors and atmospheric pressure sensors are installed near each source point, sink point and node of the urban gas municipal pipeline network. The medium pressure sensors are used to monitor the absolute pressure of the medium at each point in real time, and the atmospheric pressure sensors are used to monitor the atmospheric pressure at each point in real time. The static absolute pressure difference at each point is obtained through iterative algorithms, and the flow velocity, flow direction, flow rate and gas consumption information of the gas in the pipeline are obtained through hydraulic calculation formulas. The specific steps for obtaining the static absolute pressure difference at each point using an iterative algorithm are as follows: Step 1: Let the source point be set {A}. Find the point with the highest gas supply pressure in set {A} and denote it as A0. Let the other elements in set {A} be Ai. Let the node be set {B} and any element in set {B} be Bi. Let the sink point be set {C} and any element in set {C} be Ci. Step 2: Collect 24-hour data from each measuring point daily, find the absolute pressure of the medium when the local gauge pressure is at its maximum, and set it as P. 绝 Record the P 绝 At the corresponding time point, read the absolute pressure value of point A0 as P0, and calculate P. 绝 -P0 is marked as the daily static absolute pressure difference of the measuring point. It is calculated every day, and the minimum absolute value is retained. After iterating for a period of time, the static absolute pressure difference of all measuring points relative to point A0 is determined, and the positive and negative signs are retained. Step 3, obtain the set of static absolute pressure differences at all source points {P} Ai静 }, the set of static absolute pressure differences of all nodes {P Bi静 }, the set of static absolute pressure differences at all sinks {P Ci静 } 2. The method for dynamic simulation of gas pipeline networks based on pressure sampling data according to claim 1, characterized in that, Taking any node Bi as the center, let the connected pipe segment be Gi, where i is an integer, and its adjacent points be any points of any nature, such as source, node, or sink. Based on the static absolute pressure difference between each point and point A0, calculate the static absolute pressure between point Bi and all its surrounding adjacent points.

3. The method for dynamic simulation of gas pipeline networks based on pressure sampling data according to claim 2, characterized in that, The method for obtaining the flow direction of gas in the pipeline is as follows: Let the static absolute pressure difference between Bi and a certain adjacent point be ΔPi. 静态 Let the corresponding pipe section be Gi, and let the absolute pressure at point Bi measured at a certain moment be P. Bi测 The measured absolute pressure value at a certain adjacent point is P. 邻测 When P 邻测 -P Bi测 -△Pi 静态 When P is greater than 0, the medium flow direction in pipe segment Gi is from the adjacent point to point Bi. 邻测 -P Bi测 -△Pi 静态 When P is less than 0, the medium flow direction in pipe segment Gi is from point Bi to the adjacent point; when P... 邻测 -P Bi测 -△Pi 静态 When the value is 0, the medium in pipe segment Gi does not flow.

4. The method for dynamic simulation of gas pipeline networks based on pressure sampling data according to claim 3, characterized in that, The hydraulic calculation formulas for high- and medium-pressure gas pipeline sections are as follows: In the formula: p i p j —Absolute pressure at the inlet and outlet nodes of the pipe section, in kPa; L—Length of the pipe section, in km; λ—the coefficient of frictional resistance of the pipe section; q k —Gas flow rate under standard conditions, in meters 3 / h; d—Inner diameter of the pipe section, mm; ρ — density of the gas, kg / m³ 3 The value is 0.7174 at 0℃ and 101.325 kPa. T—Temperature of the gas, unit: K, T=T0+t℃, where t is the temperature of the medium; Z—Gas compressibility factor, which is set to 1 when the gas pressure is less than 1.2 MPa; T0—Gas temperature under standard conditions, unit: K, take T0 = 273.16 K; K—Equivalent absolute roughness of the inner surface of the pipe section; Re – Reynolds number.

Images