Gas pipeline leakage positioning method based on big data

Abstract

The invention provides a gas pipeline leakage positioning method based on big data, and belongs to the field of pipeline management. The problem that the gas pipeline leakage positioning efficiency is low is solved. The method specifically comprises the following steps: S1, calculating loss coefficients of a main pipeline and branch pipelines; s2, acquiring the gas transmission amount and the gas pressure in each pipeline, and judging whether the gas pipeline leaks or not in combination with the gas pressure-gas transmission amount change equation and the loss coefficients of the main pipeline and the branch pipelines; if not, not processing; if so, marking the fault main pipeline; s3, obtaining the in-pipe air pressure of the fault main pipeline and the in-pipe air pressure of all the branch pipelines corresponding to the fault main pipeline, and determining a leakage area and leakage time; s4, the leakage pipeline, the leakage area and the leakage time are collected and fed back; related data of the gas pipeline are obtained, processed and analyzed, the leakage area and the leakage time of the pipeline are determined and fed back, and the safety of gas transportation is improved.

Description

Technical Field

[0001] The present invention discloses a gas pipeline leakage locating method based on big data, which relates to the field of pipeline management. Background Art

[0002] The existing methods for locating gas pipeline leaks have the following shortcomings:

[0003] High cost: The existing gas pipeline leak location method requires a large investment, including the purchase, installation and maintenance of sensor equipment, which requires high capital. At the same time, the gas pipeline leak location also requires technical workers to master sensor technology, Internet of Things communication technology, big data platform, data analysis and machine learning, which places high demands on the technical capabilities of personnel.

[0004] Data quality issues: The accuracy of existing methods for locating gas pipeline leaks is closely related to the quality of the data. The accuracy and reliability of sensors and the stability of the communication network will directly affect the quality of the data. If the sensor fails or the network connection is unstable, data distortion may occur, affecting the accuracy of leak location.

[0005] High requirements for data processing capabilities: Big data technology requires powerful data storage and processing capabilities, especially in large-scale pipeline networks under monitoring, where the amount of data is huge; existing gas pipeline leak location methods will have insufficient processing capabilities when processing large amounts of data in real time, resulting in data processing delays or losses, affecting the accuracy of real-time monitoring and leak location. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a gas pipeline leakage locating method based on big data, aiming to solve the problem of low efficiency of gas pipeline leakage locating.

[0007] In order to achieve the above object, the present invention is implemented through the following technical solutions: A gas pipeline leakage locating method based on big data includes:

[0008] Step S1: Obtain the number, length and radius of the main pipelines in the target area, and the number, length and radius of the branch pipelines; obtain the normal operation information of the gas station, and calculate the loss coefficients of the main pipelines and branch pipelines;

[0009] Step S2: construct a gas pressure-gas volume change equation based on normal operation information; obtain the gas volume of the gas station and the gas volume and gas pressure in each pipeline, and combine the gas pressure-gas volume change equation and the loss coefficient of the main pipeline and branch pipeline to determine whether the gas pipeline has a leak; if not, do not process it; if it does, mark the faulty main pipeline;

[0010] Step S3: Obtain the gas pressure in the faulty main pipeline, obtain the gas pressure in all branch pipelines corresponding to the faulty main pipeline, and determine the leaking pipeline; obtain the gas pressure in the upstream and downstream pipelines of the leaking pipeline to determine the leakage area; obtain the gas concentration corresponding to the current time and the leakage area, and infer the gas leakage time by combining the gas diffusion model;

[0011] Step S4: Summarize the leaking pipeline, leaking area and leaking time as an inspection report and provide feedback; continue to inspect the gas pipeline and update the inspection report.

[0012] Furthermore, the specific steps of step S1 are as follows:

[0013] Step S11: Normal operation information indicates: the total gas transmission volume of the gas station in a single day, the total gas transmission volume of all main pipelines and branch pipelines, the gas transmission time and the gas pressure in the pipeline;

[0014] Get the number of main pipes pe; the radius r corresponding to each main pipe (1) ~r (pe) , the number of branch pipes pl (1) ~pl (pe) ;

[0015] 1st to pl of the 1st main pipeline (1) Radius of root branch pipe ri(1,1)~ri(1,pl (1) );

[0016] Similarly, the 1st to plth (pe) Radius of root branch pipe ri(pe,1)~ri(pe,pl (pe) );

[0017] Step S12: the total gas transmission volume VV of the gas station;

[0018] Total gas flow rate V of the 1st to peth main pipelines (1) ~V (pe) , gas transmission time ta (1) ~ta (pe) ; Calculate V (1) ~V (pe) of and Va;

[0019] The total gas flow of all branch pipelines of the first main pipeline is Vi(1,1)~Vi(1,pl (1) ), gas transmission time tb(1,1)~tb(1,pl (1) ); calculate Vi(1,1)~Vi(1,pl (1) ) and Vb (1) ;

[0020] Similarly, the total gas volume of all branch pipelines of the pe-th main pipeline is Vi(pe,1)~Vi(pe,pl (pe) ), gas transmission time tb(pe,1)~tb(pe,pl (pe) ); calculate Vi(pe,1)~Vi(pe,pl (pe) ) and Vb (pe) ;

[0021] Step S13: The total gas volume corresponding to the i-th main pipeline is recorded as V (i) , with a radius of r (i) , the equivalent transmission speed is vl (i) , gas delivery time is ta (i) ;

[0022] Define calculation formula 1-1:

[0023] According to formula 1-1, calculate the equivalent transmission speed vl of the 1st to peth main pipelines (1) ~vl (pe) ;

[0024] Calculate vl (1) ~vl (pe) The average value avl.

[0025] Furthermore, the subsequent steps of step S13 are as follows:

[0026] Step S14: The loss coefficient of the i-th main pipeline is wa (i) , define calculation formula 1-2: ρ represents the gas density;

[0027] According to formula 1-2, calculate the loss coefficient wa of the 1st to peth main pipes (1) ~wa (pe) ;

[0028] Step S15: Repeat the calculation of wa (1) ~wa (pe) Steps to calculate the loss coefficients wb(1,1)~wb(1,pl of all branch pipes of the first main pipe (1) );

[0029] Step S151: Define calculation formula 2-1:

[0030] Among them, r(1,j), vi(1,j) and tb(1,j) represent the radius, equivalent transmission speed and gas transmission time of the jth branch pipeline of the first main pipeline, respectively. The value range of j is: 1~pl (1) ;

[0031] According to formula 2-1, calculate the equivalent transmission speed of all branch pipes of the first main pipe vi(1,1)~vi(1,pl (1) );

[0032] Calculate vi(1,1)~vi(1,pl (1) ) is the average value, denoted as avi;

[0033] Step S152: Define calculation formula 2-2:

[0034] Among them, wb(1,j) and Vi(1,j) represent the loss coefficient and total gas transmission volume of the jth branch pipeline of the first main pipeline, respectively;

[0035] According to calculation formula 2-2, calculate the loss coefficients wb(1,1)~wb(1,pl of all branch pipes corresponding to the first main pipe. (1) );

[0036] Step S16: Repeat the calculation of wb(1,1)~wb(1,pl (1) ) and calculate the loss coefficients of all branch pipes corresponding to the 2nd to peth main pipes, and obtain wb(2,1)~wb(pe,pl (pe) ) and proceed to step S2.

[0037] Furthermore, the specific steps of step S2 are as follows:

[0038] Step S21: The length l of the first to the peth main pipelines (1) ~l (pe) ;

[0039] The length of all branch pipes corresponding to the main pipes is li(1,1)~li(pe,pl (pe) );

[0040] Step S22: The gas pressure in the first to peth main pipelines Pm (1) ~Pm (pe) ;

[0041] 1st to pl of the 1st main pipeline (1) The air pressure in the root branch pipe is Pi(1,1)~Pi(1,pl (1) );

[0042] Similarly, the 1st to plth (pe) The air pressure in the root branch pipe is Pi(pe,1)~Pi(pe,pl (pe) );

[0043] Step S23: The radius r of the first main pipe (1) 、Total gas volume V(1) and gas delivery time ta (1) ;

[0044] The radius of all branch pipes of the first main pipe is ri(1,1)~ri(1,pl (1) ), total gas transmission volume Vi(1,1)~Vi(1,pl (1) ), gas transmission time tb(1,1)~tb(1,pl (1) );

[0045] Calculate the error coefficient wn of the first main pipeline (1) ;

[0046] Step S24: Repeat the calculation of wn (1) The same steps as above are used to calculate the error coefficients wn for the second to the peth main pipes. (2) ~wn (pe) ; Calculate wn (2) ~wn (pe) The average value wr;

[0047] Assume that the gas flow rate of the ath main pipeline is Q (a) , the pressure inside the tube is P (a) ;

[0048] Assume that the number of all branch pipelines of the ath main pipeline is y, and the gas flow rate of the bth branch pipeline of the ath main pipeline is Q (a，b) , the pressure inside the tube is P (a，b) , length L (a，b) , with a radius of r (a，b) ;

[0049] Construct the air pressure-gas flow change equation:

[0050]

[0051] Among them, P (a，o) It represents the gas delivery volume of the oth branch pipeline of the ath main pipeline; μa represents the dynamic viscosity of the gas.

[0052] Furthermore, the subsequent steps of step S24 are as follows:

[0053] Step S25: Obtain the actual gas delivery volume Qw ​​of the gas station; obtain the actual gas delivery volume Qa of the 1st to peth main pipelines (1) ~Qa (pe) , actual pressure in the tube Pa (1) ~Pa (pe) ;

[0054] Get the first to the first pl corresponding to the first main pipeline (1) The actual gas flow of the root and branch pipelines is Qb(1,1)~Qb(1,pl(1) ), the actual pressure in the pipe is Pb(1,1)~Pb(1,pl (1) );

[0055] Similarly, the 1st to plth pipes corresponding to the peth pipe (pe) The actual gas flow of the root and branch pipelines is recorded as Qb(pe,1)~Qb(pe,pl (pe) ), the actual pressure in the pipe is Pb(pe,1)~Pb(pe,pl (p) );

[0056] Step S26: Obtain the loss coefficient wa of the first to peth main pipelines (1) ~wa (pe) , the loss coefficients of all branch pipes corresponding to the 1st to peth main pipes are wb(1,1)~wb(pe,pl (pe) );

[0057] Assume that the actual gas flow of the mth main pipeline is Qa (m) , the loss coefficient is wa (m) ;

[0058] Assume that the number of all branch pipelines corresponding to the mth main pipeline is n, and the actual gas flow of the qth branch pipeline of the mth main pipeline is Qb (m,q) , the loss coefficient is wb (m,q) ;

[0059] Define equation 3-4:

[0060] Among them, ε represents the judgment value;

[0061] Qq represents the calibration value:

[0062]

[0063] Step S27: Substitute the data in step S25 into equation 3-4 to determine whether equation 3-4 holds true;

[0064] If true, skip the subsequent steps;

[0065] If not, substitute the data in step S25 into the air pressure-gas delivery volume variation equation, mark the main pipeline that does not satisfy the air pressure-gas delivery volume variation equation as a faulty main pipeline, and proceed to step S3.

[0066] Furthermore, the specific steps of step S23 are as follows:

[0067] Step S231: Extract tb(1,1)~tb(1,pl (1) ) is the minimum value tll in the equation, and the equivalent gas transmission volume VG is calculated;

[0068] Define calculation formula 3-1: Vg(1,x) = (tll / tb(1,x)) × Vi(1,x); where Vg(1,x), tb(1,x) and Vi(1,x) represent the equivalent gas flow, gas flow time and total gas flow of the xth branch pipeline of the first main pipeline, respectively;

[0069] According to the calculation formula 3-1, calculate the equivalent gas flow rate of all branch pipelines of the first main pipeline Vg(1,1)~Vg(1,pl (1) );

[0070] Step S232: Calculate the pressure difference of the first branch pipe ΔP(1,1), ΔP(1,1) = Pm (1) -Pi(1,1);

[0071] Similarly, the first pl (1) The pressure difference between the root and branch pipes ΔP(1,pl (1) ), ΔP(1,pl (1) )=Pm (1) -Pi(1,pl (1) );

[0072] Step S233: Obtain the equivalent transmission speeds vi(1,1) to vi(1,pl of all branch pipes of the first main pipe (1) );

[0073] Calculate the Reynolds numbers Re(1,1)~Re(1,pl of all branch pipes corresponding to the first main pipe (1) );

[0074] Step S234: Assume that the pressure difference between the first main pipeline and the xth branch pipeline is ΔP(1,x), and the error coefficient is ww(1,x); Assume that the radius of the xth branch pipeline of the first main pipeline is ri(1,x), and the length is li(1,x); the value range of x is: 1~pl (1) ;

[0075] Define equation s:

[0076]

[0077] According to equation s, calculate the relative position of the first main pipeline to the first to the first pl (1) The error coefficient of the root branch pipeline is ww(1,1)~ww(1,pl (1) );

[0078] Calculate ww(1,1)~ww(1,pl (1) ) as the average value of wn (1) .

[0079] Furthermore, the specific steps of step S3 are as follows:

[0080] Step S31: Count the number of faulty main pipelines, denoted as a1;

[0081] Get the gas volume of the first to alth fault main pipelines and record it as eQ (1) ~eQ (al) , the pressure inside the tube is recorded as eP (1) ~P (al) ;

[0082] Step S32: Obtain the number of all branch pipes corresponding to the first to the al-th faulty main pipes, recorded as pn (1) ~pn (al) ;

[0083] All branch pipelines corresponding to the first faulty main pipeline are taken as target pipelines, the first faulty main pipeline and the target pipelines are analyzed, the leaking pipelines corresponding to the first faulty main pipeline and the target pipelines are determined, and the leakage time of the gas is inferred;

[0084] Step S33: Repeat the processing steps for the first faulty main pipeline to process the second to the al-th faulty main pipelines.

[0085] Furthermore, the specific steps of step S32 are as follows:

[0086] Step S321: Set pn (1) Recorded as pnl; the gas delivery volume of the 1st to pnlth target pipelines is recorded as Qbl (1) ~Qbl (pnl) , the pressure inside the tube is recorded as Pbl (1) ~Pbl (pnl) ;

[0087] Step S322: Obtain the gas transmission volume Qw ​​of the gas station; obtain the loss coefficient wd of the first faulty main pipeline, and the loss coefficients of the first to pnlth target pipelines are recorded as wl (1) ~wl (pnl) ;

[0088] Judgment (Qw×wd)<eQ (1) whether it is established;

[0089] Step S323: If (Qw×wd)<eQ (1) If it is established, then it is known that the leakage area is in the first faulty main pipeline;

[0090] Step S324: If (Qw×wd)<eQ (1) If it is not true, the leakage area is in the 1st to pnlth target pipes;

[0091] Step S325: Get the current time, recorded as dt;

[0092] Assume that the expected gas flow rate of the leaking pipeline is qAt, the gas flow rate is nAt, the radius is Ar, the length is Ah, the gas concentration in the leaking area is Cx, and the time of the leak is tx;

[0093] Define the fuel gas diffusion model and obtain equations 5-1 to 5-3;

[0094] If the leakage area is upstream, let the farthest distance of the upstream leakage area be Lma, equation 5-1:

[0095]

[0096] If the leakage area is downstream, let the farthest distance of the downstream leakage area be Lla, equation 5-2:

[0097]

[0098] If the leakage area is in the middle, Equation 5-3:

[0099]

[0100] Where exp represents the exponential function (with base e), σ represents the diffusion coefficient of the gas, and the calculation formula of σ is:

[0101] Step S326: Obtain the gas concentrations in the leakage areas corresponding to the first faulty main pipeline and the first to pnlth target pipelines, and substitute them inversely into equations 5-1 to 5-3 to calculate the gas leakage time.

[0102] Furthermore, the specific steps of step S323 are as follows:

[0103] Step S3231: Define equation 4-1:

[0104] Among them, Qbl (t) represents the gas delivery volume of the tth target pipeline, wl (t) represents the loss coefficient of the tth target pipeline;

[0105] Determine whether equation 4-1 holds true;

[0106] If so, no leakage occurs in the 1st to pnlth target pipelines, and step S3233 is skipped;

[0107] If not, then the 1st to pnlth target pipelines leak;

[0108] Step S3232: Only the first faulty main pipeline leaks;

[0109] Calculate the expected gas flow of the first faulty main pipeline, denoted as eQq, eQq = Qw × wd;

[0110] The length of the first faulty main pipeline is obtained as eL, and the radius is recorded as eR; (where eL∈{l (1) ~l (pe)}, eR∈{r (1) ~r (pe)})

[0111] Calculate the air pressure loss of the first faulty main pipeline, denoted as ΔePm;

[0112]

[0113] Step S3233: repeat step S3232 to determine the leakage area of ​​the first faulty main pipeline;

[0114] The gas flow rate of the kth target pipeline is recorded as Qbl (k) , the loss coefficient is denoted as wl (k) ; The value range of k is: 1~pnl;

[0115] Define equation 4-4: |Qbl(k)-(eQ(1)×wl(k))≤ε;

[0116] Qbl (1) ~Qbl (pnl) and wl (1) ~wl (pnl) Substitute into equation 4-4, extract and mark the target pipeline satisfying equation 4-4 as the faulty branch pipeline;

[0117] Repeat the steps of determining the leakage area of ​​the first faulty main pipeline to determine the leakage area of ​​the faulty branch pipeline.

[0118] Furthermore, the specific steps of step S3232 are as follows:

[0119] Step S32321: Set eQq, Qbl (1) ~Qbl (pnl) and Pbl (1) ~Pbl (pnl) Substitute the reverse into the air pressure-gas flow rate change equation to calculate the ideal in-pipe air pressure of the first faulty main pipeline, recorded as qPm;

[0120] Step S32322: Obtain the gas pressure uuP in the upstream pipe and the gas pressure ddP in the downstream pipe of the first faulty main pipe;

[0121] Define equation 4-2:

[0122] Relationship 4-3:

[0123] Step S32323: If relation 4-2 holds true, the leakage area is in the upstream area of ​​the first faulty main pipeline;

[0124] The farthest distance Lmm from the upstream leakage area; compare (uuP / qPm) and (ΔePm / qPm) to determine the calculation formula for Lmm;

[0125] If (uuP / qPm)≥(ΔePm / qPm), then Lmm=(uuP / qPm)×eL;

[0126] If (uuP / qPm)<(ΔePm / qPm), then Lmm=(ΔePm / qPm)×eL;

[0127] The leakage area of ​​the first faulty main pipeline is in the area Lmm downstream of the air inlet;

[0128] Step S32324: If relation 4-3 holds true, the leakage area is in the downstream area of ​​the first faulty main pipeline;

[0129] The farthest distance Lll from the upstream leakage area; compare (ddP / qPm) and (ΔePm / qPm) to determine the calculation formula for Lll;

[0130] If (ddP / qPm)≥(ΔePm / qPm), then Lll=(ddP / qPm)×eL;

[0131] If (ddP / qPm)<(ΔePm / qPm), then Lll=(ΔePm / qPm)×eL;

[0132] The leakage area of ​​the first faulty main pipeline is in the area of ​​L11 of the reverse flow at the outlet;

[0133] Step S32325: If neither the relational expression 4-2 nor the relational expression 4-3 holds true, the leakage area is in the middle area of ​​the first faulty main pipeline;

[0134] The leakage area of ​​the first faulty main pipeline is in the [Lmm, (Lmm+Lll)] area downstream of the air inlet.

[0135] Compared with the prior art, the present invention has the following beneficial effects:

[0136] Real-time monitoring and rapid response: The present invention can capture the changes in gas concentration in the gas pipeline and in the air in real time. When abnormal gas concentration is detected in the gas pipeline, the present invention can provide real-time feedback and locate the leakage area according to the gas flow rate per unit time in the gas pipeline and the air pressure in the pipe, and reversely infer the leakage time based on the gas concentration in the air, thereby providing gas companies with the ability to respond to pipeline leaks in a timely manner, reducing the response time after an accident and improving safety.

[0137] Automation and intelligence: The method of the present invention does not rely on human intervention. When technicians deploy the data processing logic of the present invention in the form of code to relevant monitoring systems or sensors, the relevant monitoring systems or sensors can have automated monitoring capabilities, issue early warnings and locate leakage areas as soon as leakage occurs, and have strong adaptability to leakage events in different environments.

[0138] Reduce labor costs: Traditional manual inspection methods often rely on a large amount of manpower and time costs, while the present invention can greatly reduce manual intervention, reduce labor costs, and improve work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0139] 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:

[0140] Figure 1 It is a schematic diagram of the method of the present invention;

[0141] Figure 2 This is a schematic diagram of the gas pipeline of the present invention;

[0142] Figure 3 This is a schematic diagram of the leakage area of ​​the present invention. DETAILED DESCRIPTION

[0143] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0144] See also Figure 1 and Figure 2 , a gas pipeline leakage location method based on big data includes:

[0145] Step S1: Obtain the number, length and radius of the main pipelines in the target area, and the number, length and radius of the branch pipelines (connected to each main pipeline); obtain the normal operation information of the gas station, and calculate the loss coefficients of the main pipelines and branch pipelines;

[0146] Normal operation information means: (assuming there is no leakage in the gas pipeline) the total gas transmission volume of the gas station in the most recent single day, the total gas transmission volume of all main pipelines and branch pipelines, the gas transmission time and the gas pressure in the pipeline;

[0147] It should be noted that the "target area" in the present invention means: a city-level area where the present invention (a gas pipeline leakage location method based on big data) is used to locate the gas pipeline leakage;

[0148] "Main pipeline" means: the main pipeline that transports gas from the gas station (in the target area) to the user area, and its diameter is usually greater than DN100; "branch pipeline" means: the auxiliary pipeline branching from the main pipeline, and its diameter is generally DN15-DN50;

[0149] The specific steps of step S1 are as follows:

[0150] Step S11: Obtain the number of main pipelines and record it as pe; record the radius of the first to the peth main pipelines as r (1) ~r (pe) ;

[0151] Get the number of branch pipes corresponding to each main pipe, denoted as pl (1) ~pl (pe) ;

[0152] The first to the first pl corresponding to the first main pipeline (1) The radius of the root branch pipe is denoted as ri(1,1)~ri(1,pl (1) );

[0153] The second main pipeline corresponds to the first to the second pl (2) The radius of the root branch pipe is denoted as ri(2,1)~ri(2,pl (2) );

[0154] By analogy, the pe-th main pipeline corresponds to the 1st to pl-th (pe) The radius of the root branch pipe is denoted as ri(pe,1)~ri(pe,pl (pe) );

[0155] Step S12: (in normal operation information) the total gas transmission volume of the gas station is recorded as VV;

[0156] The total gas volume of the 1st to peth main pipelines is denoted as V (1) ~V (pe) , gas transmission time is recorded as ta (1) ~ta (pe) ; Calculate V (1) ~V (pe) The sum of is denoted as Va;

[0157] The total gas volume of all branch pipelines corresponding to the first main pipeline is recorded as Vi(1,1)~Vi(1,pl (1) ), the gas transmission time is recorded as tb(1,1)~tb(1,pl (1) ); calculate Vi(1,1)~Vi(1,pl (1) ), denoted as Vb (1) ;

[0158] The total gas volume of all branch pipelines corresponding to the second main pipeline is recorded as Vi(2,1)~Vi(2,pl (2) ), the gas transmission time is recorded as tb(2,1)~tb(2,pl (2) ); calculate Vi(2,1)~Vi(2,pl (2) ), denoted as Vb (2) ;

[0159] Similarly, the total gas volume of all branch pipelines corresponding to the pe-th main pipeline is recorded as Vi(pe,1)~Vi(pe,pl (pe) ), the gas transmission time is recorded as tb(pe,1)~tb(pe,pl (pe) ); calculate Vi(pe,1)~Vi(pe,pl (pe) ), denoted as Vb (pe) ;

[0160] Step S13: The total gas volume corresponding to the i-th main pipeline is recorded as V (i) , the radius is denoted as r (i) , (gas) equivalent transmission speed is recorded as vl (i) , gas transmission time is recorded as ta (i) ; The value range of i is: 1~pe;

[0161] Define calculation formula 1-1:

[0162] According to formula 1-1, calculate the equivalent transmission speed vl of the (gas) of the 1st to peth main pipelines (1) ~vl (pe) ;

[0163] Calculate vl (1) ~vl (pe) The average value is denoted as avl;

[0164] Step S14: The loss coefficient of the i-th main pipeline is recorded as wa (i) , define calculation formula 1-2: Where ρ represents the density of the gas;

[0165] According to formula 1-2, calculate the loss coefficient wa of the 1st to peth main pipes (1) ~wa(pe) ;

[0166] Step S15: Repeat the calculation of wa (1) ~wa (pe) Calculate the loss coefficients of all branch pipes corresponding to the first main pipe and obtain wb(1,1)~wb(1,pl (1) );

[0167] Step S151: Define calculation formula 2-1:

[0168] Among them, r(1,j), vi(1,j) and tb(1,j) represent the radius, equivalent transmission speed and gas transmission time of the jth branch pipeline of the first main pipeline, respectively. The value range of j is: 1~pl (1) ;

[0169] According to the calculation formula 2-1, calculate the equivalent transmission speed of the gas in all branch pipelines corresponding to the first main pipeline: vi(1,1)~vi(1,pl (1) );

[0170] Calculate vi(1,1)~vi(1,pl (1) ) is the average value, denoted as avi;

[0171] Step S152: Define calculation formula 2-2:

[0172] Among them, wb(1,j) and Vi(1,j) represent the loss coefficient and total gas transmission volume of the jth branch pipeline of the first main pipeline, respectively;

[0173] According to calculation formula 2-2, calculate the loss coefficients wb(1,1)~wb(1,pl of all branch pipes corresponding to the first main pipe. (1) );

[0174] Step S16: Repeat the calculation of wb(1,1)~wb(1,pl (1) ) and calculate the loss coefficients of all branch pipes corresponding to the 2nd to peth main pipes, and obtain wb(2,1)~wb(pe,pl (pe) ).

[0175] Step S2: construct the gas pressure-gas volume change equation (of the gas transmission pipeline) based on the normal operation information; obtain the gas volume of the gas station and the gas volume and gas pressure in each pipeline (in unit time), and combine the gas pressure-gas volume change equation and the loss coefficient of the main pipeline and branch pipeline to determine whether the gas pipeline has a leak; if not, do not process it (and skip step S3); if it has, mark the faulty main pipeline;

[0176] The specific steps of step S2 are as follows:

[0177] Step S21: The length of the first to the peth main pipelines is recorded as l (1) ~l (pe) ;

[0178] The first to the first pl corresponding to the first main pipeline (1) The length of the root branch pipe is denoted as li(1,1)~li(1,pl (1) );

[0179] The second main pipeline corresponds to the first to the second pl (2) The length of the root branch pipe is denoted as li(2,1)~li(2,pl (2) );

[0180] By analogy, the pe-th main pipeline corresponds to the 1st to pl-th (pe) The length of the root branch pipe is denoted as li(pe,1)~li(pe,pl (pe) );

[0181] Step S22: (In normal operation information) record the pressure in the pipes of the 1st to peth main pipes as Pm (1) ~Pm (pe) ;

[0182] The first to the first pl corresponding to the first main pipeline (1) The air pressure inside the root branch pipe is recorded as Pi(1,1)~Pi(1,pl (1) );

[0183] The second main pipeline corresponds to the first to the second pl (2) The air pressure inside the root branch pipe is recorded as Pi(2,1)~Pi(2,pl (2) );

[0184] By analogy, the pe-th main pipeline corresponds to the 1st to pl-th (pe) The air pressure inside the root branch pipe is recorded as Pi(pe,1)~Pi(pe,pl (pe) );

[0185] Step S23: (In normal operation information) obtain the radius r of the first main pipeline (1) 、Total gas volume V (1) and gas delivery time ta (1) ;

[0186] The first main pipe corresponds to all the branch pipe radii ri(1,1)~ri(1,pl (1) ), total gas transmission volume Vi(1,1)~Vi(1,pl (1) ), gas transmission time tb(1,1)~tb(1,pl(1) );

[0187] Calculate the error coefficient wn of the first main pipeline (pressure-gas flow) (1) ;

[0188] Step S231: Extract tb(1,1)~tb(1,pl (1) ), denoted as tll;

[0189] Calculate the equivalent gas volume of the (first) main pipeline (taking the reference time tll) as VG, VG = (tll / ta (1) )×V (1) ;

[0190] Define calculation formula 3-1: Vg(1,x) = (tll / tb(1,x)) × Vi(1,x); where Vg(1,x), tb(1,x) and Vi(1,x) represent the equivalent gas flow, gas flow time and total gas flow of the xth branch pipeline of the first main pipeline, respectively. The value range of x is: 1~pl (1) ;

[0191] According to the calculation formula 3-1, calculate the equivalent gas flow rate Vg(1,1)~Vg(1,pl of all branch pipelines corresponding to the first main pipeline (1) );

[0192] Step S232: Calculate the pressure difference ΔP(1,1) between the first main pipeline and the first branch pipeline, ΔP(1,1) = Pm (1) -Pi(1,1);

[0193] The pressure difference of the second branch pipe (relative to the first main pipe) is ΔP(1,2), ΔP(1,2) = Pm (1) -Pi(1,2);

[0194] By analogy, (the first main pipeline relative to) the first pl (1) The pressure difference between the root and branch pipes ΔP(1,pl (1) ), ΔP(1,pl (1) )=Pm (1) -Pi(1,pl (1) );

[0195] Step S233: Obtain the equivalent transmission speeds of the gas of all branch pipelines corresponding to the first main pipeline vi(1,1)~vi(1,pl (1) );

[0196] Define calculation formula 3-2: Re(1,x) = (ρ×vi(1,x)×2×ri(1,x)) / μa;

[0197] Where Re(1,x), vi(1,x) and ri(1,x) represent the Reynolds number, equivalent transmission velocity and radius of the xth branch pipe of the first main pipe, respectively; ρ represents the density of the gas, μa represents the dynamic viscosity of the gas; the value range of x is: 1~pl (1) ;

[0198] According to formula 3-2, calculate the Reynolds numbers Re(1,1)~Re(1,pl of all branch pipes corresponding to the first main pipe. (1) );

[0199] Step S234: Assume that the pressure difference between the first main pipeline and the xth branch pipeline is ΔP(1,x), and the error coefficient is ww(1,x); Assume that the radius of the xth branch pipeline of the first main pipeline is ri(1,x), and the length is li(1,x); the value range of x is: 1~pl (1) ;

[0200] Define Equation 3-3:

[0201]

[0202] Substitute the data in steps S231 to S233 into equation 3-3 to calculate the first main pipeline relative to the first to the first pl (1) The error coefficient of the root branch pipeline is ww(1,1)~ww(1,pl (1) );

[0203] Calculate ww(1,1)~ww(1,pl (1) ) as the error coefficient wn of the first main pipeline (gas pressure-gas delivery) (1) ;

[0204] Step S24: Repeat the calculation of wn (1) The same steps as above are used to calculate the (pressure-gas delivery) error coefficient wn of the second to the peth main pipelines. (2) ~wn (pe) ;

[0205] Calculate wn (2) ~wn (pe) The average value of is denoted as wr;

[0206] In the unit time (generally set to 1 second, the user or relevant technical personnel can adjust the length of the "unit time" according to actual needs), the gas delivery volume of the ath main pipeline is Q (a) , the pressure inside the tube is P (a) ;

[0207] Assume that the number of all branch pipelines of the ath main pipeline is y, and the gas flow rate of the bth branch pipeline of the ath main pipeline is Q (a，b), the pressure inside the tube is P (a，b) , length L (a，b) , with a radius of r (a，b) ; The value range of b is: 1~y;

[0208] Construct the gas pressure (of the gas transmission pipeline) - gas transmission volume change equation:

[0209]

[0210] Among them, P (a，o) represents the gas flow rate of the oth branch pipeline of the ath main pipeline, the value range of o is: 1~y, and o≠b; ρ represents the density of the gas, and μa represents the dynamic viscosity of the gas;

[0211] Step S25: (per unit time) obtain the gas transmission volume of the gas station (in operation), recorded as Qw; obtain the gas transmission volume of the 1st to peth main pipelines (in operation), recorded as Qa (1) ~Qa (pe) , the air pressure in the tube is recorded as Pa (1) ~Pa (pe) ;

[0212] Get the first to the first pl corresponding to the first main pipeline (1) The gas flow rate of the root branch pipeline (in operation) is recorded as Qb(1,1)~Qb(1,pl (1) ), the pressure inside the tube is recorded as Pb(1,1)~Pb(1,pl (1) );

[0213] The second main pipeline corresponds to the first to the second pl (2) The gas flow rate of the root branch pipeline (in operation) is recorded as Qb(2,1)~Qb(2,pl (2) ), the pressure inside the tube is recorded as Pb(2,1)~Pb(2,pl (2) );

[0214] By analogy, the pe-th main pipeline corresponds to the 1st to pl-th (pe) The gas flow rate of the root branch pipeline (in operation) is recorded as Qb(pe,1)~Qb(pe,pl (pe) ), the pressure inside the tube is recorded as Pb(pe,1)~Pb(pe,pl (p) );

[0215] Step S26: Obtain the loss coefficient wa of the first to peth main pipelines (1) ~wa (pe) , obtain the loss coefficients wb(1,1)~wb(pe,pl of all branch pipes corresponding to the 1st to peth main pipes (pe) );

[0216] (In unit time) the gas flow of the mth main pipeline (in operation) is recorded as Qa (m) , the loss coefficient is recorded as wa (m) , the value range of m is: 1~pe;

[0217] The number of all branch pipes corresponding to the mth main pipe is recorded as n, and the value range of n changes with m; (for example, if m is 1, the value range of n is: 1~pl (1) ; m is 2, then the value range of n is: 1~pl (2) ; Similarly, if m is pe, then the value range of n is: 1~pl (pe) ;)

[0218] The gas flow rate of the qth branch pipeline (in operation) of the mth main pipeline (in unit time) is recorded as Qb (m,q) , the loss coefficient is denoted as wb (m,q) , the value range of q is: 1~n;

[0219] Define equation 3-4:

[0220] Wherein, ε represents the (error) judgment value; (the value of ε is 0.1, and the user or relevant technical personnel can adjust the value of ε according to actual needs)

[0221] Qq represents the calibration value, and the calculation formula of Qq is:

[0222]

[0223] Step S27: Substitute the data in step S25 into equation 3-4 to determine whether equation 3-4 holds true;

[0224] If so, it means that there is no gas pipeline leakage accident in the target area, and the subsequent steps (i.e., step S3) are skipped;

[0225] If not, it means that a gas pipeline leakage accident has occurred in the target area. The data in step S25 is substituted into the gas pressure-gas delivery volume change equation, and the main pipeline that does not satisfy the gas pressure-gas delivery volume change equation is marked as a faulty main pipeline.

[0226] Step S3: Obtain the gas pressure in the faulty main pipeline, obtain the gas pressure in all branch pipelines corresponding to the faulty main pipeline, and determine the leaking pipeline (main pipeline or branch pipeline); obtain the gas pressure in the upstream and downstream pipes of the leaking pipeline, and determine the leakage area (of the leaking pipeline); obtain the gas concentration (in the air) corresponding to the current time and the leakage area, and infer the gas leakage time by combining the gas diffusion model;

[0227] The specific steps of step S3 are as follows:

[0228] Step S31: Count the number of faulty main pipelines, denoted as al; (al≤pe)

[0229] (In the data in step S25) the gas delivery volume of the first to the al-th faulty main pipelines (in operation) is obtained and recorded as eQ (1) ~eQ (al) , the pressure inside the tube is recorded as eP (1) ~P (al) ;(in,

[0230] Step S32: Obtain the number of all branch pipes corresponding to the first to the al-th faulty main pipes, recorded as pn (1) ~pn (al) ;(in, )

[0231] All branch pipelines corresponding to the first faulty main pipeline are taken as target pipelines, the first faulty main pipeline and the target pipelines are analyzed, the leaking pipelines corresponding to the first faulty main pipeline and the target pipelines are determined, and the leakage time of the gas is inferred;

[0232] Step S321: Set pn (1) (in the data of step S25) obtain the gas volume of the first to the pnlth target pipeline and record it as Qbl (1) ~Qbl (pnl) , the pressure inside the tube is recorded as Pbl (1) ~Pbl (pnl) ;(in, )

[0233] Step S322: Obtaining the gas transmission volume Qw ​​of the gas station (in operation) (in unit time);

[0234] The loss coefficient of the first faulty main pipeline is recorded as wd, and the loss coefficients of the first to pnlth target pipelines are recorded as wl (1) ~wl (pnl) ;(in, )

[0235] Judgment (Qw×wd)<eQ (1) Whether it is established, determine the leakage locations of the first faulty main pipeline and the first to pnlth target pipelines;

[0236] Step S323: If (Qw×wd)<eQ (1) If it is established, it means that the first faulty main pipeline has a leak, and the known leakage area is in the first faulty main pipeline;

[0237] Step S3231: Define equation 4-1:

[0238] Among them, Qbl (t) represents the gas delivery volume of the tth target pipeline, wl (t) represents the loss coefficient of the t-th target pipeline, and the value range of t is: 1~pnl; ε represents the (error) judgment value;

[0239] Substitute the gas delivery volume and loss coefficient of the 1st to pnlth target pipelines into equation 4-1 to determine whether equation 4-1 holds true;

[0240] If established, no leakage occurs in the 1st to pnlth target pipelines, and the process goes to step S3232 (skipping step S3233);

[0241] If not, the first to the pnlth target pipelines leak, and the process goes to step S3233;

[0242] Step S3232: Only the first faulty main pipeline leaks;

[0243] Calculate the expected gas flow of the first faulty main pipeline, denoted as eQq, eQq = Qw × wd;

[0244] The length of the first faulty main pipeline is obtained as eL, and the radius is recorded as eR; (where eL∈{l (1) ~l (pe)}, eR∈{r (1) ~r (pe)})

[0245] Calculate the air pressure loss of the first faulty main pipeline, denoted as ΔePm;

[0246]

[0247] Step S32321: Set eQq, Qbl (1) ~Qbl (pnl) and Pbl (1) ~Pbl (pnl) Substitute the reverse into the air pressure-gas flow rate change equation to calculate the ideal in-pipe air pressure of the first faulty main pipeline, recorded as qPm;

[0248] Step S32322: Please refer to Figure 3 , obtain the air pressure in the upstream pipe of the first faulty main pipe (i.e., the air pressure at the air inlet) as uuP, and the air pressure in the downstream pipe (i.e., the air pressure at the air outlet) as ddP;

[0249] Define equation 4-2:

[0250] Relationship 4-3:

[0251] Step S32323: If relation 4-2 holds true, the leakage area is in the upstream area of ​​the first faulty main pipeline;

[0252] The farthest distance to the upstream leakage area is recorded as Lmm; compare (uuP / qPm) and (ΔePm / qPm) to determine the calculation formula of Lmm;

[0253] If (uuP / qPm)≥(ΔePm / qPm), then Lmm=(uuP / qPm)×eL;

[0254] If (uuP / qPm)<(ΔePm / qPm), then Lmm=(ΔePm / qPm)×eL;

[0255] The leakage area of ​​the first faulty main pipeline is in the area Lmm downstream of the gas inlet (i.e., along the direction of gas flow in the pipeline);

[0256] Step S32324: If relation 4-3 holds true, the leakage area is in the downstream area of ​​the first faulty main pipeline;

[0257] The farthest distance to the upstream leakage area is recorded as Lll; compare (ddP / qPm) and (ΔePm / qPm) to determine the calculation formula of Lll;

[0258] If (ddP / qPm)≥(ΔePm / qPm), then Lll=(ddP / qPm)×eL;

[0259] If (ddP / qPm)<(ΔePm / qPm), then Lll=(ΔePm / qPm)×eL;

[0260] The leakage area of ​​the first faulty main pipeline is in the area L11 of the gas outlet counterflow (i.e., in the opposite direction of the gas flow in the pipeline);

[0261] Step S32325: If neither the relational expression 4-2 nor the relational expression 4-3 holds true, the leakage area is in the middle area of ​​the first faulty main pipeline;

[0262] The leakage area of ​​the first faulty main pipeline is in the [Lmm, (Lmm+Lll)] area downstream of the air inlet (of the first faulty main pipeline);

[0263] It should be noted that in the present invention, "Relationship 4-2" is judged first, and "Relationship 4-3" is judged later; that is, only when "Relationship 4-2 is not established", "Relationship 4-3" will be judged;

[0264] Step S3233: repeat step S3232 to determine the leakage area of ​​the first faulty main pipeline;

[0265] The gas flow rate of the kth target pipeline is recorded as Qbl (k) , the loss coefficient is denoted as wl (k) ; The value range of k is: 1~pnl;

[0266] Define the relationship 4-4: |Qbl(k)-(eQ(1)×wl(k))≤ε; where ε represents the (error) judgment value;

[0267] Qbl (1) ~Qbl (pnl) and wl (1) ~wl (pnl) Substitute into equation 4-4, extract and mark the target pipeline satisfying equation 4-4 as the faulty branch pipeline;

[0268] Repeat the step of determining the leakage area of ​​the first faulty main pipeline (i.e., step S322) to determine the leakage area of ​​the faulty branch pipeline;

[0269] Step S324: If (Qw×wd)<eQ (1) If it is not true, it means that there is no leakage in the first faulty main pipeline, and the leakage area is in the first to pnlth target pipelines;

[0270] Repeat the processing steps of step S323 to determine the leakage areas of the 1st to pnlth target pipelines;

[0271] Step S325: Get the current time, recorded as dt;

[0272] Assume that the expected gas flow rate of the leaking pipeline is qAt, the gas flow rate is nAt, the radius is Ar, the length is Ah, the gas concentration in the leaking area is Cx, and the time of the leak is tx;

[0273] Define the gas diffusion model of fuel gas (in air) and obtain equations 5-1 to 5-3;

[0274] If the leakage area is upstream, let the farthest distance of the upstream leakage area be Lma, equation 5-1:

[0275]

[0276] If the leakage area is downstream, let the farthest distance of the downstream leakage area be Lla, equation 5-2:

[0277]

[0278] If the leakage area is in the middle, Equation 5-3:

[0279]

[0280] Where exp represents the exponential function (with base e), σ represents the diffusion coefficient of the gas, and the calculation formula of σ is:

[0281] Step S326: Obtain the gas concentration (in the air) in the leakage area corresponding to the first faulty main pipeline and the first to pnlth target pipelines, and substitute it into equations 5-1 to 5-3 in reverse order to calculate the gas leakage time;

[0282] Step S33: Repeat the processing steps for the first faulty main pipeline (ie, step S32) to process the second to the al-th faulty main pipelines.

[0283] Step S4: Summarize the leaking pipeline, leaking area and leaking time as an inspection report and provide feedback; continue to inspect the gas pipeline (including the main pipeline and branch pipeline) and update the inspection report.

[0284] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technical personnel in this field according to actual conditions. For example, if there are weight coefficients and proportional coefficients, their set sizes are to quantify each parameter to obtain a specific value, which is convenient for subsequent comparison. Regarding the size of the weight coefficient and the proportional coefficient, it is sufficient as long as it does not affect the proportional relationship between the parameter and the quantized value.

[0285] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A gas pipeline leakage location method based on big data, characterized in that: The method comprises: Step S1: Obtain the number, length and radius of the main pipelines in the target area, and the number, length and radius of the branch pipelines; obtain the normal operation information of the gas station, and calculate the loss coefficients of the main pipelines and branch pipelines; Step S2: construct a gas pressure-gas volume change equation based on normal operation information; obtain the gas volume of the gas station and the gas volume and gas pressure in each pipeline, and combine the gas pressure-gas volume change equation and the loss coefficient of the main pipeline and branch pipeline to determine whether the gas pipeline has a leak; if not, do not process it; if it does, mark the faulty main pipeline; Step S3: Obtain the gas pressure in the faulty main pipeline, obtain the gas pressure in all branch pipelines corresponding to the faulty main pipeline, and determine the leaking pipeline; obtain the gas pressure in the upstream and downstream pipelines of the leaking pipeline to determine the leakage area; obtain the gas concentration corresponding to the current time and the leakage area, and infer the gas leakage time by combining the gas diffusion model; Step S4: Summarize the leaking pipeline, leaking area and leaking time as an inspection report and provide feedback; continue to inspect the gas pipeline and update the inspection report.

2. A gas pipeline leakage location method based on big data according to claim 1, characterized in that: The specific steps of step S1 are as follows: Step S11: Obtain the total gas transmission volume of the gas station in a single day, the total gas transmission volume of all main pipelines and branch pipelines, the gas transmission time and the gas pressure in the pipeline, and obtain normal operation information; Get the number of main pipes pe; the radius of each main pipe r (1) ~r (pe) , the number of branch pipes pl (1) ~pl (pe) ; 1st to pl of the 1st main pipeline (1) Radius of root branch pipe ri(1,1)~ri(1,pl (1) ); Similarly, the 1st to plth (pe) Radius of root branch pipe ri(pe,1)~ri(pe,pl (pe) ); Step S12: The total gas volume VV of the gas station; the total gas volume V of the 1st to peth main pipelines (1) ~V (pe) , gas transmission time ta (1) ~ta (pe) ; Calculate V (1) ~V (pe) of and Va; The total gas flow of all branch pipelines of the first main pipeline is Vi(1,1)~Vi(1,pl (1) ), gas transmission time tb(1,1)~tb(1,pl (1) ); calculate Vi(1,1)~Vi(1,pl (1) ) and Vb (1) Similarly, the total gas volume of all branch pipelines of the pe-th main pipeline is Vi(pe,1)~Vi(pe,pl (pe) ), gas transmission time tb(pe,1)~tb(pe,pl (pe) ); calculate Vi(pe,1)~Vi(pe,pl (pe) ) and Vb (pe) ; Step S13: The total gas volume corresponding to the i-th main pipeline is recorded as V (i) , with a radius of r (i) , the equivalent transmission speed is vl (i) , gas transmission time is ta (i) ; Define calculation formula 1-1: Calculate the equivalent transmission speed vl of the 1st to peth main pipelines respectively (1) ~vl (pe) ; Calculate vl (1) ~vl (pe) The average value avl.

3. A gas pipeline leakage location method based on big data according to claim 2, characterized in that: The subsequent steps of step S13 are as follows: Step S14: The loss coefficient of the i-th main pipeline is wa (i) , define calculation formula 1-2: ρ represents the gas density; Calculate the loss coefficient wa of the 1st to peth main pipelines respectively (1) ~wa (pe) ; Step S15: Calculate the loss coefficients wb(1,1) to wb(1,pl of all branch pipes of the first main pipe. (1) ); Step S151: Define calculation formula 2-1: Among them, r(1,j), vi(1,j) and tb(1,j) represent the radius, equivalent transmission speed and gas transmission time of the jth branch pipeline of the first main pipeline, respectively; Calculate the equivalent transmission speeds vi(1,1)~vi(1,pl of all branch pipes of the first main pipe (1) ); calculate vi(1,1)~vi(1,pl (1) ) is the average value, denoted as avi; Step S152: Define calculation formula 2-2: Wherein, wb(1,j) and Vi(1,j) represent the loss coefficient and total gas flow of the jth branch pipeline of the first main pipeline, respectively; calculate the loss coefficients wb(1,1)~wb(1,pl (1) ); Step S16: Calculate the loss coefficients of all branch pipes corresponding to the second to the peth main pipes, and obtain wb(2,1)~wb(pe,pl (pe) ) and proceed to step S2.

4. A gas pipeline leakage location method based on big data according to claim 3, characterized in that: The specific steps of step S2 are as follows: Step S21: The length l of the first to the peth main pipelines (1) ~l (pe) ; The length of all branch pipes corresponding to the main pipes is li(1,1)~li(pe,pl (pe) ); Step S22: The gas pressure in the first to peth main pipelines Pm (1) ~Pm (pe) ; The first to the first pl of the first main pipeline (1) The air pressure in the root branch pipe is Pi(1,1)~Pi(1,pl (1) ); Similarly, the 1st to plth (pe) The air pressure in the root branch pipe is Pi(pe,1)~Pi(pe,pl (pe) ); Step S23: Calculate the error coefficient wn of the first main pipeline (1) ; Step S24: Calculate the error coefficients wn of the second to peth main pipelines (2) ~wn (pe) ; Calculate wn (2) ~wn (pe) The average value wr; Assume that the gas flow rate of the ath main pipeline is Q (a) , the pressure inside the tube is P (a) ; Let the number of all branch pipelines of the ath main pipeline be y, and the gas flow of the bth branch pipeline of the ath main pipeline be Q (a，b) , the pressure inside the tube is P (a，b) , length L (a，b) , with a radius of r (a，b) ; Construct the air pressure-gas flow change equation: Among them, P (a，o) It represents the gas delivery volume of the oth branch pipeline of the ath main pipeline; μa represents the dynamic viscosity of the gas.

5. A gas pipeline leakage location method based on big data according to claim 4, characterized in that: The step S2 further comprises: Step S25: Obtain the actual gas delivery volume Qw ​​of the gas station; obtain the actual gas delivery volume Qa of the 1st to peth main pipelines (1) ~Qa (pe) , actual pressure in the tube Pa (1) ~Pa (pe) ; Get the first to the first pl corresponding to the first main pipeline (1) The actual gas flow of the root and branch pipelines is Qb(1,1)~Qb(1,pl (1) ), the actual pressure in the pipe is Pb(1,1)~Pb(1,pl (1) ); the 1st to plth corresponding to the peth main pipeline (pe) The actual gas flow of the root and branch pipelines is recorded as Qb(pe,1)~Qb(pe,pl (pe) ), the actual pressure in the pipe is Pb(pe,1)~Pb(pe,pl (p) ); Step S26: Obtain the loss coefficient wa of the first to peth main pipelines (1) ~wa (pe) , the loss coefficients of all branch pipes corresponding to the 1st to peth main pipes are wb(1,1)~wb(pe,pl (pe) ); Assume that the actual gas flow of the mth main pipeline is Qa (m) , the loss coefficient is wa (m) ; Assume that the number of all branch pipelines corresponding to the mth main pipeline is n, and the actual gas flow of the qth branch pipeline of the mth main pipeline is Qb (m,q) , the loss coefficient is wb (m,q) ; Define equation 3-4: Among them, ε represents the judgment value; Qq represents the calibration value: Step S27: Determine whether the relationship 3-4 is established; if established, skip the subsequent steps; If not, substitute the data in step S25 into the air pressure-gas delivery volume variation equation, mark the main pipeline that does not satisfy the air pressure-gas delivery volume variation equation as a faulty main pipeline, and proceed to step S3.

6. A gas pipeline leakage location method based on big data according to claim 4, characterized in that: The specific steps of step S23 are as follows: Step S231: Extract tb(1,1)~tb(1,pl (1) ) is the minimum value tll, and the equivalent gas transmission volume VG is calculated, VG = (tll / ta (1) )×V (1) ; Define calculation formula 3-1: Vg(1,x) = (tll / tb(1,x)) × Vi(1,x); where Vg(1,x), tb(1,x) and Vi(1,x) represent the equivalent gas flow, gas flow time and total gas flow of the xth branch pipeline of the first main pipeline, respectively; calculate the equivalent gas flow of all branch pipelines of the first main pipeline Vg(1,1) ~ Vg(1,pl (1) ); Step S232: Calculate the pressure difference of the first branch pipe ΔP(1,1), ΔP(1,1) = Pm (1) -Pi(1,1); Similarly, the pl (1) The pressure difference between the root and branch pipes ΔP(1,pl (1) ), ΔP(1,pl (1) )=Pm (1) -Pi(1,pl (1) ); Step S233: Obtain the equivalent transmission speeds vi(1,1) to vi(1,pl of all branch pipes of the first main pipe (1) );Calculate the Reynolds numbers Re(1,1)~Re(1,pl of all branch pipes corresponding to the first main pipe (1) ); Step S234: Assume that the pressure difference between the first main pipeline and the xth branch pipeline is ΔP(1,x), and the error coefficient is ww(1,x); Assume that the radius of the xth branch pipeline of the first main pipeline is ri(1,x), and the length is li(1,x); define the equation: Calculate the first main pipeline relative to the first to the first pl (1) The error coefficient of the root branch pipeline is ww(1,1)~ww(1,pl (1) ) ; Calculate the average value of the error coefficient as wn (1) .

7. A gas pipeline leakage location method based on big data according to claim 5, characterized in that: The specific steps of step S3 are as follows: Step S31: Count the number of faulty main pipelines al; obtain the gas delivery volume eQ of the first to the alth faulty main pipelines (1) ~eQ (al) , the air pressure in the tube eP (1) ~P (al) ; Step S32: Obtain the number of all branch pipes corresponding to the first to the al-th faulty main pipes, recorded as pn (1) ~pn (al) ; All branch pipelines corresponding to the first faulty main pipeline are taken as target pipelines, the first faulty main pipeline and the target pipelines are analyzed, the leaking pipelines corresponding to the first faulty main pipeline and the target pipelines are determined, and the leakage time of the gas is inferred; Step S33: Repeat the processing steps for the first faulty main pipeline to process the second to the al-th faulty main pipelines.

8. A gas pipeline leakage location method based on big data according to claim 7, characterized in that: The specific steps of step S32 are as follows: Step S321: Set pn (1) Recorded as pnl; Get the gas delivery volume Qbl of the 1st to pnlth target pipelines (1) ~Qbl (pnl) , the air pressure in the tube is Pbl (1) ~Pbl (pnl) ; Step S322: Obtain the gas transmission volume Qw ​​of the gas station; obtain the loss coefficient wd of the first faulty main pipeline, and the loss coefficients wl of the first to pnlth target pipelines (1) ~wl (pnl) ; Judgment (Qw×wd)<eQ (1) whether it is established; Step S323: If (Qw×wd)<eQ (1) If it is established, then it is known that the leakage area is in the first faulty main pipeline; Step S324: If (Qw×wd)<eQ (1) If it is not true, the leakage area is in the 1st to pnlth target pipes; Step S325: Get the current time, recorded as dt; assume that the expected gas flow rate of the leaking pipeline is qAt, the gas flow rate is nAt, the radius is Ar, the length is Ah, the gas concentration in the leaking area is Cx, and the time when the leak occurs is tx; Define the fuel gas diffusion model and obtain equations 5-1 to 5-3; If the leakage area is upstream, let the farthest distance of the upstream leakage area be Lma, equation 5-1: If the leakage area is downstream, let the farthest distance of the downstream leakage area be Lla, equation 5-2: If the leakage area is in the middle, Equation 5-3: Among them, exp represents the exponential function, σ represents the diffusion coefficient of the gas, and the calculation formula of σ is: Step S326: Obtain the gas concentrations in the leakage areas corresponding to the first faulty main pipeline and the first to pnlth target pipelines, and substitute them inversely into equations 5-1 to 5-3 to calculate the gas leakage time.

9. A gas pipeline leakage location method based on big data according to claim 8, characterized in that: The specific steps of step S323 are as follows: Step S3231: Define equation 4-1: Among them, Qbl (t) represents the gas delivery volume of the tth target pipeline, wl (t) represents the loss coefficient of the tth target pipeline; Determine whether equation 4-1 holds true; If so, no leakage occurs in the 1st to pnlth target pipelines, and step S3233 is skipped; If not, then the 1st to pnlth target pipelines leak; Step S3232: Only the first faulty main pipeline leaks; calculate the expected gas flow rate of the first faulty main pipeline, denoted as eQq, eQq = Qw × wd; Obtain the length of the first faulty main pipeline, recorded as eL, and the radius, recorded as eR; calculate the air pressure loss of the first faulty main pipeline, recorded as ΔePm; Step S3233: repeat step S3232 to determine the leakage area of ​​the first faulty main pipeline; The gas flow rate of the kth target pipeline is recorded as Qbl (k) , the loss coefficient is denoted as wl (k) ; Define equation 4-4: |Qbl(k)-(eQ(1)×wl(k))≤ε; Qbl (1) ~Qbl (pnl) and wl (1) ~wl (pnl) Substitute into equation 4-4, extract and mark the target pipeline that satisfies equation 4-4 as the faulty branch pipeline; repeat the steps of determining the leakage area of ​​the first faulty main pipeline to determine the leakage area of ​​the faulty branch pipeline.

10. A gas pipeline leakage location method based on big data according to claim 9, characterized in that: The specific steps of step S3232 are as follows: eQq、Qbl (1) ~Qbl (pnl) and Pbl (1) ~Pbl (pnl) Substitute the reverse into the air pressure-gas flow rate change equation to calculate the ideal in-pipe air pressure of the first faulty main pipeline, recorded as qPm; Obtain the upstream pipe pressure uuP and the downstream pipe pressure ddP of the first faulty main pipeline; Define equation 4-2: Relationship 4-3: If equation 4-2 holds true, the leakage area is in the upstream area of ​​the first faulty main pipeline; The farthest distance Lmm from the upstream leakage area; compare (uuP / qPm) and (ΔePm / qPm) to determine the calculation formula for Lmm; If (uuP / qPm)≥(ΔePm / qPm), then Lmm=(uuP / qPm)×eL; If (uuP / qPm)<(ΔePm / qPm), then Lmm=(ΔePm / qPm)×eL; The leakage area of ​​the first faulty main pipeline is in the area Lmm downstream of the air inlet; If equation 4-3 holds true, the leakage area is in the downstream area of ​​the first faulty main pipeline; The farthest distance Lll from the upstream leakage area; compare (ddP / qPm) and (ΔePm / qPm) to determine the calculation formula for Lll; If (ddP / qPm)≥(ΔePm / qPm), then Lll=(ddP / qPm)×eL; If (ddP / qPm)<(ΔePm / qPm), then Lll=(ΔePm / qPm)×eL; The leakage area of ​​the first faulty main pipeline is in the area of ​​L11 of the reverse flow at the outlet; If neither equation 4-2 nor equation 4-3 holds true, the leakage area is in the middle area of ​​the first faulty main pipeline; the leakage area of ​​the first faulty main pipeline is in the [Lmm, (Lmm+Lll)] area downstream of the air inlet.

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