CN104034800A - Assessment method and system for hydraulic detection of conveying pipeline and for state of carrier fluid pipeline - Google Patents

Abstract

The invention provides an assessment method for hydraulic detection of a conveying pipeline. The method comprises the following steps: step 1, generating pressure waves in a pipeline fluid flowing along the pipeline; step 2, detecting an interaction signal generated after interaction between the pressure waves and local pipeline variation, wherein the interaction signal is a pressure signal reflected via interaction between the pressure waves and local pipeline variation and used for compensating for a pressure effect generated by the pipeline fluid, and the characteristic of the interaction signal refers to changing of the amplitude of the interaction signal; step 3, determining the condition of the wall of the pipeline after contact between the pressure waves and the local pipeline wall via the characteristic of the received interaction signal; and step 4, determining the scope of local pipeline variation in the condition of the pipeline based on the interaction signal. The assessment method can be used in a variety of conveying pipelines and in pipelines made of a variety of materials, including metal pipelines, ceramic pipelines and plastic pipelines, and has a wide application scope.

Description

Conveyance conduit hydraulic detection and delivery fluid line state evaluating method and system

Technical field

The present invention relates to a kind of pipeline evaluation areas, be especially applied to the assessment of localized variation in pipeline conditions, be specifically related to conveyance conduit hydraulic detection and delivery fluid line state evaluating method and system.

Background technology

Pipe network is the topmost infrastructure of water supply and sewage enterprise, and the Main Function of pipe network is to carry maybe by the fluid collection disperseing.Pipe network also can carry out the conveying of oil and natural gas.According to different demands, these pipe networks can be built on the ground or be embedded in underground.When the protective lining of metallic conduit is destroyed, along with the variation of time, inner pipe wall can form corrosion, and causes growing tubercle bacillus.Metallic conduit outside also can be corroded, and the metal on pipeline generates corrosion by-products and forms pit at pipe surface.Take cement pipe as example, and after cement pipe breakage, cement leachate can enter in water body by flow ipe.The problems such as these can cause tube wall attenuation, the loss of pipeline elastic strength, these problems can cause the increase of booster risk.

The existence of booster problem, especially to jumbo pipeline burst, can cause significant impact to surrounding resident and environment.Therefore, public public institution need to spend a large amount of work and carry out pipeline conditions assessment, and the pipeline going wrong is detected and repaired.Along with the pipe network increase of tenure of use, safe and reliable for guaranteeing pipe network operation, the maintenance that pipe network is continued is very important.

The method of conventional pipelines state-detection has multiple, wherein applying maximum is intrusive mood detection method, from pipeline section section sampling, observe extent of corrosion, but this damage type method of testing is not adopted in the industry gradually, be mainly because sampling need to be excavated pipeline, and after sampling, need pipeline to carry out follow-up reparation.Another kind of detection technique is Close Circuit Television (CCTV) camera technique, and this technology need to extend in pipeline conventionally, and only by shooting, tube wall situation is carried out to visual classification.Other non-intrusion type detection methods, as ultrasonic meter, a given measuring position, are directly measured pipe thickness, and this method depends on that pipeline is on the ground or underground.In addition, supersonic technique need to carry out Pre-Evaluation to a certain zone duct position, and adopts this kind of method time and effort consuming for the pipeline location of discrete distribution in bulk zone.Above two kinds of technology all can only detect the duct size information of assigned address, but can accurately not assess the damaged situation of tube wall.

Another kind of Dynamic Non-Destruction Measurement launches voice signal in the initial end of pipeline, position probing acoustical signal along pipeline in its downstream, the mean propagation velocity by record from pipeline transmitting terminal to test side sound wave, deducibility goes out sound wave through the pipeline situation of part.This process has the non-damaged advantage detecting, but sonic detection technology can only add up to measure to the pipeline quality of surveying range, can not damaged position occur to tube wall and locate accurately.

In the result obtaining at average measurement, wherein have most without the pipeline of changing, can be replaced, this is due to the damaged situation skewness of tube wall, and pipeline all can exist defect in production and installation process.Public public institution, in pipe network maintenance management work, is mainly to find and repair the conduit region going wrong, rather than whole pipeline is replaced.

In sum, a kind of new technology of Patent exploitation of the present invention and method, assessment pipeline present situation, and the accuracy that improves judgement piping failure.

Summary of the invention

For defect of the prior art, the object of this invention is to provide a kind of pipeline conditions evaluating system and method, this appraisal procedure mainly comprises along duct orientation generation pressure wave, and in detected pressures ripple and pipeline, there is the pressure wave interactive signal after the local pipeline making a variation interacts, according to the signal analysis pipeline situation detecting.The method also comprises according to the sequential of pressure wave interactive signal reception determines that the position of local variation occurs pipeline, determines according to the pressure wave interactive signal feature receiving the scope that pipeline morphs.

According to a kind of conveyance conduit hydraulic detection appraisal procedure provided by the invention, comprise the steps:

Step 1: produce pressure wave in the pipeline fluid along Flows;

Step 2: the interactive signal producing after the local variation of detected pressures ripple and pipeline interacts, wherein, the pressure signal of interactive signal for having an effect and reflect by described pressure wave and the local variation of pipeline, be used for compensating the pressure effect producing due to pipeline fluid, the feature of interactive signal is the change of interactive signal amplitude;

Step 3: by the feature of the interactive signal that receives, determine the tube wall situation after pressure wave contacts with local tube wall;

Step 4: based on interactive signal, determine the scope of the local variation of pipeline in pipeline situation.

Preferably, in described step 1, particularly, along pipeline, in source position, change pipeline pressure and/or change characteristic of fluid, wherein, changing pipeline pressure or change characteristic of fluid and be included in source position exhaust fluid and/or stop discharging.

Preferably, described step 3, specifically comprises the steps:

Step 3.1: transmitting transient pressure wave source;

Step 3.2: pressure wave and pipeline generation reciprocation, and produce interactive signal;

Step 3.3: receive interactive signal;

Step 3.4: set up pipeline transition model, resolve pressure wave interactive signal, determine pipeline situation.

Preferably, it is characterized in that, for the reflection wave of appointment, having the interactive signal corresponding with it, described step 4 comprises the steps:

Step 4.1 ＇: set up pipeline section transition model;

Step 4.2 ＇: receive the interactive signal after the local variation of pipeline section;

Step 4.3 ＇: determine Joukowsky equation variable parameter;

Step 4.4 ＇: calculate and definite pipeline section range of variation;

Wherein, transition model is set up as follows:

Step I 1: determine pipeline variation type;

Step I 2: manually set pipe leakage amount;

Step I 3: determine pressure-wave emission speed;

Step I 4: build-up pressure ripple pipe transmmision is ruled equation;

Step I 5: transition model tuning.

Preferably, improve as follows the intensity of interactive signal:

Steps A: subtract pulse step, is specially: in removal interactive signal, segment pulse is in conjunction with transition wave head;

Step B: low-pass filter step, is specially: utilize the filtrator of low pass bandwidth that the interactive signal by after processing of step A is filtered, the filtering signal of receiving is further removed;

Step C: add pulse step, be specially: the segment pulse of the interactive signal before processing of step A is reintroduced back to the interactive signal after processing by step B, and generates trendless signal.

Preferably, in step 3, by compensate the variation of average velocity of wave can be further the accurate position of pipeline variation, wherein average velocity of wave is defined as: to the corresponding instantaneous celerity of different period pressure waves, by the pressure-wave emission speed to different pipe sections, carry out statistical study, obtain the average velocity of propagating in this type of conduits.

Preferably, in step 4, comprise the steps:

-the size that pressure interactive signal is changed is converted into the variation of the local velocity of wave of pressure wave, is specially:

$\mathrm{\ΔH}=-\frac{a}{g}\mathrm{\ΔV}$ Formula (1)

Wherein, Δ H is for specifying reflection wave pressure head to change, and a is pressure wave velocity of propagation along pipeline in fluid, and g is gravity acceleration constant, and Δ V is change in flow size;

-the local velocity of wave of pressure wave is changed with local pipe thickness and sets up corresponding relation, be specially:

$a=\sqrt{\frac{K/\mathrm{\ρ}}{1+(K/E)(D/t)c}}---\left(2\right)$

Wherein, the bulk modulus that K is water, the density that ρ is water, the elastic modulus that E is tube wall, t is pipe thickness, and D is internal diameter of the pipeline, and c is pipeline constraint factor, c=1 when pipeline is flexible interface, c=1-v when pipeline is rigid conduit interface ², v is Poisson ratio, and rigid conduit interface is welding junction or the cement class encapsulant of pipeline outer wall mounting strap saddle type pedestal, and flexible interface is for bearing the pipe joint of a certain amount of axial line displacement and relative angle displacement.

According to a kind of conveyance conduit hydraulic detection evaluating system provided by the invention, comprise as lower device:

The first pressure wave generator, produces pressure wave for the pipeline fluid along Flows;

The first interactive signal pick-up unit, for detection of the interactive signal producing after pressure wave and the local variation interaction of pipeline, wherein, the pressure signal of interactive signal for having an effect and reflect by described pressure wave and pipeline localized variation, be used for compensating the pressure effect producing due to pipeline fluid, the feature of interactive signal is the change of interactive signal amplitude of variation;

The first data processing equipment, for the feature of the interactive signal by receiving, determines the tube wall situation after pressure wave contacts with local tube wall, and based on interactive signal, determines the scope of the local variation of pipeline in pipeline situation.

According to a kind of delivery fluid line state evaluating method provided by the invention, comprise the steps:

Step 1: along duct orientation, produce pressure wave in source position;

Step 2: detect a plurality of by pressure wave and the rear interactive signal producing of pipeline localized variation interaction at different monitoring locations, wherein, the pressure signal of interactive signal for having an effect and reflect by described pressure wave and the local variation of pipeline, be used for compensating the pressure effect producing due to pipeline fluid, the feature of interactive signal is the change of interactive signal amplitude of variation; Wherein, detection position comprises source position;

Step 3: the position of determining localized variation in pipeline by the interactive signal time;

Step 4: the degree of the feature judgement pipeline localized variation based on interactive signal.

Preferably, described step 3 comprises the steps:

Step 301: determine that pressure wave is in ducted velocity of propagation;

Step 302: record pressure wave and transmit and receive the mistiming;

Step 303: the distance of calculating pipeline localized variation based on speed time formula;

Step 304: calculate pipeline localized variation position with respect to the position of pressure wave source.

Preferably, after transmitting pressure wave and pipeline localized variation interact, produce pressure wave interactive signal, this interactive signal to pipeline localized variation degree (as pipe thickness, pipe lining corrosion condition etc.) all there is corresponding interactive signal intensity, based on this reflected signal strength feature, determine pipeline localized variation size.

According to a kind of delivery fluid line state evaluating method evaluating system provided by the invention, comprise as lower device:

The second pressure wave generator, for along duct orientation, produces pressure wave in source position;

The second interactive signal pick-up unit, for detect a plurality of interactive signals by producing after pressure wave and the interaction of pipeline localized variation at different monitoring locations, wherein, the pressure signal of interactive signal for having an effect and reflect by described pressure wave and the local variation of pipeline, be used for compensating the pressure effect producing due to pipeline fluid, the feature of interactive signal is the change of interactive signal amplitude of variation; Wherein, detection position comprises source position;

The second data processing equipment, determines the position of localized variation in pipeline by the interactive signal time, and the degree of the judgement of the feature based on interactive signal pipeline localized variation.

Compared with prior art, the present invention has following beneficial effect:

The present invention can be applicable in the pipeline of multiple conveying purposes, and can be used for comprising metal tube, and ceramic pipe and plastic tube, in the pipeline of interior various materials, have a wide range of applications field.

Accompanying drawing explanation

By reading the detailed description of non-limiting example being done with reference to the following drawings, it is more obvious that other features, objects and advantages of the present invention will become:

Fig. 1 is pipeline conditions evaluation work flow process;

Fig. 2 is pipeline sectional view to be assessed;

Fig. 3 is pressure wave interactive signal curve;

Fig. 4 be damaged in various degree pipeline section contrast schematic diagram wherein, ts represents the corrosion-free thickness of tube wall;

Fig. 5 is that pressure wave interactive signal goes trending flow process;

Fig. 6 is the trend process of going in pressure wave interactive signal;

Fig. 7 is the impact of the quick-acting answering pressure ripple of mean wave interactive signal in pipeline;

Fig. 8 is that in pipeline, pressure wave source and measurement point are longitudinally schemed;

Fig. 9 is that different measuring is put corresponding velocity of wave curve;

Figure 10 is pressure wave source G point both sides R1 and L1 gaging pressure ripple interactive signal;

Figure 11 is that transition model is determined pipeline range of variation flow process;

Figure 12 is that transition model analysis pipeline section pressure wave interactive signal changes;

Figure 13 is that transition model global search step prediction velocity of wave changes;

Figure 14 is the average velocity of wave of simulation and pipe thickness variation;

Figure 15 is pipeline section actual measurement and the pressure signal comparison based on global search prediction;

Figure 16 is different measuring point measured result and analog result comparison;

Figure 17 is that SCE and ultrasonic technique are to the comparison of pipe thickness measurement result;

Figure 18 is the first measurement point pressure wave interactive signal stack result;

Figure 19 is the second measurement point pressure wave interactive signal stack result.

In figure:

200 is pipeline;

210 is outer wall;

220 is liner.

Embodiment

Below in conjunction with specific embodiment, the present invention is described in detail.Following examples will contribute to those skilled in the art further to understand the present invention, but not limit in any form the present invention.It should be pointed out that to those skilled in the art, without departing from the inventive concept of the premise, can also make some distortion and improvement.These all belong to protection scope of the present invention.

The problem existing for current techique in current pipeline condition evaluation, the invention provides and a kind ofly take transition model as basic pipeline conditions appraisal procedure, its estimation flow as shown in Figure 1:

This workflow can be applicable in town water and the isometric state estimation apart from water supply line of agricultural irrigation, shown in its pipeline section Fig. 2.Shown in Fig. 2 is one section of typical mild carbon steel sand-cement slurry liner pipe 200, and its outer wall 210 is comprised of mild carbon steel, and liner 220 is comprised of sand-cement slurry.Diagram outer diameter tube is 762mm, inside diameter D=727.5mm, wall thickness t=17.25mm.Pipe lining worsens since 220, and deepens gradually, finally can have influence on the serviceable life of pipeline.

Produce pressure according to the flow process shown in Fig. 1, by pressure generator, in pipeline 200, produce pressure wave, in pipeline hydrant position, open rapidly and closed shutter, now the current along pipeline can stop gradually, and the process that water stops gradually along pipeline flow-direction is equal to the transition wave head of pressure wave formation along the process of pipe transmmision.Before closing hydrant and forming transition wave head, first discharge the water of about 5000L, make to form in pipeline stable current.In the present invention, by being installed in hydrant downstream, the pressure generator of customization closes the current of side discharge.The water emitting can be used for urban afforestation water or can store the place of water.

The ring flange that pressure-generating device comprises and diameter valve is suitable, ball valve, torsion spring device and a nozzle (diameter is between 25～50mm) that regulates discharge capacity size, the water of discharge is connected to pond by the pvc pipe road of diameter 100mm, and PVC delivery pipe is installed multiple reverse bottom valve in order to alleviate the negative pressure from main pipeline.Two propeller flowmeters are installed simultaneously for detection of emission flow on pvc pipe.

For obtaining the detailed pressure wave interactive signal in a certain region, between two washout valves of pipeline, need to generate one group of pressure wave on the ground, and underground pipeline only can connect by hydrant (urban duct is especially true).Now pressure generator is mainly comprised of ball valve, torsion spring device, the reverse bottom valve of nozzle and flowmeter.

Detected pressures is mainly that local variation occurs to interact and the detection of the pressure wave interactive signal that produces for pressure wave in pipeline and a plurality of pipeline.In the present invention, pressure detector is mainly comprised of conversion equipment and pen recorder.Generally, according to situation on the spot, measurement point is selected in to hydrant position and introduces pressure transducer.Pressure wave detecting device, notebook computer and data record unit are synchronized in GPS device and other measurement points, each measurement point configures pressure-recording system, pipeline transition frequency 2000～10000Hz, causing transition time is 4～6 minutes, and the instrument setup times of each measurement point is probably 10 minutes.The local variation of pipeline, comprising: the variation of tube wall elasticity modulus, the variation of pipe thickness, the long-pending variation of cross-section of pipeline.

In field of the present invention, also have the pressure-detecting device of some widespread uses, as to take Venturi effect and nautical receiving set be basic pressure gauge.In addition, pressure gauge can also be realized on-line monitoring, by Long-distance Control, carries out pressure data record.Fig. 3 is pressure wave interactive signal curve, in figure with pressure head (m) the Representation Equation to the time, pressure wave interactive signal 300 is comprised of three sections of different curves, 310 sections is initial unchanged part, this section of areal pressure is constant substantially.320 sections of unexpected redirects of pressure are mainly mineralization pressure ripples in pipeline.330 sections of rapid change in pressure, are mainly that pressure wave runs in pipeline local variation and forms reflection wave, as tube wall breakage etc.

Determine determining by the time series analysis of 330 sections of pressure wave interactive signals in Fig. 3 of the local variation of position pipeline position.In this example, in pipeline, the definite of average velocity of wave is constant based on hypothesis pipe thickness, and according to definite velocity of wave, it is definite that time of peaking can arrive by pressure change in the position of pipeline variation.

Determine that in scope pipeline, range of variation can be determined by Joukowsky equation, Joukowsky equation is expressed as follows:

$\mathrm{\ΔH}=-\frac{a}{g}\mathrm{\ΔV}---\left(1\right)$

In formula (1), a be pressure wave in fluid along pipe transmmision speed, g is gravity acceleration constant, Δ H is for specifying reflection wave pressure head to change, Δ V is change in flow size.

Δ V can determine by flowmeter, or calculates according to floss hole caliber size, and in pipeline, pressure-wave emission speed a can calculate by following formula:

$a=\sqrt{\frac{K/\mathrm{\ρ}}{1+(K/E)(D/t)c}}---\left(2\right)$

In formula (2), the bulk modulus that K is water, the density that ρ is water, the elastic modulus that E is tube wall, t is pipe thickness, and D is internal diameter of the pipeline, and c is pipeline constraint factor, c=1 when pipeline is flexible interface, c=1-v when pipeline is full restriction pipeline ², v is Poisson ratio, entirely restrict pipeline is to weld or bolt flange joint comprising of pipeline outer wall mounting strap saddle type pedestal.

By above formula, can determine ducted pressure-wave emission speed a, in Fig. 3 pressure interactive signal curve, the calculating of pressure drop can be determined pipe thickness and internal diameter of the pipeline.For the pipeline of sand-cement slurry liner, pipe thickness can be converted into by sand-cement slurry and metallic conduit elastic modulus ratio the metal pipe-wall of condition of equivalent thickness.

In pipeline, damage in various degree can be observed by Fig. 4 the impact of pressure-wave emission speed a and pipe thickness, (a) for there is no sand-cement slurry liner, being (b) corrosion that 1mm is thick, is (c) corrosion that 2mm is thick, (d) be the corrosion that 3mm is thick, t _sfor corrosion-free thickness.The internal diameter of different extent of corrosions and corresponding velocity of wave are listed in table 1:

Table 1 is damaged corresponding pipeline data in various degree

Piping failure degree and damage location can be according to the pressure wave interactive signal data acquisitions providing above.

In the fluid of foregoing description, the generation of pressure wave can cause pressure effect compensation problem simultaneously.In some cases, before producing pressure wave, in pipeline, also do not form static state or steady state flow, this is mainly in order to guarantee, the water of discharge all to be collected.Therefore the dipping and heaving that, the generation of pressure wave causes the long-term concussion of hydrodynamic pressure and causes total pressure depends on the reflection wave signal of mensuration.

In this case, by eliminating the process of these trend, improve pressure wave interactive signal intensity, its analysis process as shown in Figure 5.

In subtract pulse pressure wave interactive signal, first segment pulse is removed in conjunction with transition wave head.The filtrator of low-pass filter low pass bandwidth filters the signal receiving, and the filtering signal of receiving is further removed.The segment pulse that adds pulsed pressure wave interactive signal is introduced into again, and generates trendless signal.Fig. 6 is 330 sections of trendless pressure wave interactive signal sections in Fig. 3, and this segment signal can be used for occurring in analysis conduit the scope of local variation.

For single measuring position, in pipeline, average velocity of wave variation range is very large, by compensate the variation of average velocity of wave can be further the accurate position of pipeline variation.

Fig. 7 represents the impact of different average velocities of wave on pressure wave interactive signal, 710 sections of signals for initial position mensuration, and 720 sections is pressure wave interactive signal separated with initial position on space.As can be seen from Figure 7, with respect to original pressure ripple, pressure wave interactive signal structural change scope is larger.This structural variation can be used for determining the average velocity of wave between initial position and measuring position.In this case, can measure the inceptive impulse relevant with source position, its length is about 7ms.When wave head arrives measurement point, pulse dispersibles into the length of 50ms.In figure, 710 sections of the corresponding original pressure ripple of 750 sections of time differences interactive signals and the second pressure wave interactive signal are 720 sections, and 750 sections and 740 sections of corresponding minimums of difference and maximum velocity of wave, calculate average velocity of wave by the time differences of 730 sections.This average velocity of wave can be applicable to revise the pressure wave interactive signal of measuring, and further accurate targeted duct damage location.

What Fig. 8 described is the longitudinal survey sheet of pipeline, and in figure, G point is pressure wave source, measurement point R1, and R2, R3 and L1, L2, L3 lays respectively at right side and the left side of pressure wave source.

In figure, pipeline 200 is the pipeline of straight line type not necessarily, and its physical features can be not identical yet, can be the pipeline being connected into by a plurality of pipeline nodes, and tubing, pipeline rout etc. are all unrestricted.Fig. 9 is according to the different velocity of wave curves in duct survey point place in Fig. 8.

In the situation that a plurality of measurement points exist, the pressure wave of being launched by pressure wave source position can be propagated to both direction.Therefore the tube wall variation situation, existing in both sides, G point position all can be detected.As previously shown, the pipeline overall status that ducted average velocity of wave may be subject in measured zone changes, and therefore can cause pressure wave interactive signal to be offset in time.

Figure 10 has shown that the measurement point R1 of G both sides, pressure wave source position and L1 pressure wave interactive signal change, and R1 is positioned at the upstream that G is ordered, and L1 is positioned at G point downstream.

As previously mentioned, the variation of average velocity of wave can be used for determining pipeline section, average velocity of wave can be definite by original pressure wave impulse waveform, and original pressure ripple interactive signal can be revised by the pipeline section flow velocity signal based on hypothesis, supposes that speed changes until obtain second segment pressure wave interactive signal.For a given pipeline section, average velocity of wave can be used for the gaging pressure ripple interactive signal that compensation is caused by time migration, and this time migration will cause the skew forward or backward of pressure wave interactive signal, and the signal of different measuring position can be connected.

Get back in Fig. 1 and determine scope step, pipeline range of variation can be definite by transition model, and in pipeline, transient flow can be calculated according to the basic unstable state continuity equation of momentum:

$\frac{\∂H}{\∂t}+\frac{a^2}{\mathrm{gA}}\frac{\∂Q}{\∂x}=0---\left(3\right)$

$\frac{\∂H}{\∂x}+\frac{1}{\mathrm{gA}}\frac{\∂Q}{\∂t}+h_f=0---\left(4\right)$

In above formula, ignore convective acceleration and slope term, in formula:

H-pressure head (m)

Q-flow (m ³/ s)

T-time coordinate

X-volume coordinate

A-pressure wave in fluid along pipe transmmision speed

Sectional area (m2) in A-pipeline

G-acceleration of gravity constant

-partial differential compute sign

In above formula (4), calculate laminar flow and turbulent skn friction coefficient h _fcan calculate by through type (5):

$h_f=\frac{\mathrm{fQ}\left|Q\right|}{{2\mathrm{gDA}}^2}+\frac{16\mathrm{\ν}}{{\mathrm{gD}}^{2}A}(\frac{\∂Q}{\∂t}*W)\left(t\right)---\left(5\right)$

In formula:

D-caliber

W-laminar flow, smooth tube turbulent flow or rough tube turbulent flow unstable state friction weight equation

F-metastable state friction factor

V-kinematic viscosity

Metastable state and unstable state friction can be respectively calculated by above-mentioned equation (5), and unstable state friction can rub in weight equation and be updated to the flow rate calculation in transient event according to unstable state.

In this example, use efficient recurrence approximate algorithm to calculate unstable state turbulent skn friction, above-mentioned equation (3) and (4) can be by method of characteristic solution partial differential equation:

$[H(x,t)-H(x-\mathrm{\Δx},t-\mathrm{\Δt})]+\frac{a}{\mathrm{gA}}[Q(x,t)-Q(x-\mathrm{\Δx},t-\mathrm{\Δt})]+{\mathrm{a\Δth}}_f=0---\left(6\right)$

$h_f=\frac{\mathrm{fQ}(x,t)\left|Q(x-\mathrm{\Δx},t-\mathrm{\Δt})\right|}{{2\mathrm{gDA}}^2}---\left(7\right)$

In formula:

Δ x-spatial spreading degree

Δ t-time discrete

H (x, t)-t is the pressure head m at pipeline location x place constantly

H (x-Δ x, t-Δ t) the discrete Δ t of-time reversal, pressure head m during the reverse discrete Δ x in locus,

Q (x, t)-t is the flow (m at pipeline location x place constantly ³/ s)

Q (x-Δ x, t-Δ t)-time discrete Δ t, flow (m during the discrete Δ x in locus ³/ s)

$[H(x,t)-H(x+\mathrm{\Δx},t-\mathrm{\Δt})]-\frac{a}{\mathrm{gA}}[Q(x,t)-Q(x+\mathrm{\Δx},t-\mathrm{\Δt})]-{\mathrm{a\Δth}}_f=0---\left(8\right)$

$h_f=\frac{\mathrm{fQ}(x,t)\left|Q(x+\mathrm{\Δx},t-\mathrm{\Δt})\right|}{{2\mathrm{gDA}}^2}---\left(9\right)$

In formula:

H (x+ Δ x, t-Δ t)-space forward is discrete, the pressure head that time reversal is discrete, m

Q (x+ Δ x, t-Δ t)-space forward is discrete, the flow that time reversal is discrete, m ³/ s

Equation (6) and (8) are C ⁺and C ^-the equation of comptability, is out of shape and is simplified the value that can solve pressure head H by equation.

$\begin{array}{c}H{(x,t)}^{+}=[H(x-\mathrm{\Δx},t-\mathrm{\Δt})+\frac{a}{\mathrm{gA}}Q(x-\mathrm{\Δx},t-\mathrm{\Δt})]\\ -[\frac{a}{\mathrm{gA}}+\frac{f}{{2\mathrm{gDA}}^2}\mathrm{a\Δt}|Q(x-\mathrm{\Δx},t-\mathrm{\Δ}t\left|\right]Q{(x,t)}^{+}\end{array}---\left(10\right)$

Wherein, ⁺represent forward harmony equation;

Above formula (10) can be reduced to

H(x,t) ⁺＝C ⁺-B ⁺Q(x,t) ⁺ （11）

C in formula ⁺representation algebra formula $[H(x-\mathrm{\Δx},t-\mathrm{\Δt})+\frac{a}{\mathrm{gA}}Q(x-\mathrm{\Δx},t-\mathrm{\Δt})],$ B ⁺representation algebra formula $[\frac{a}{\mathrm{gA}}+\frac{f}{{2\mathrm{gDA}}^2}\mathrm{a\Δt}|Q(x-\mathrm{\Δx},t-\mathrm{\Δt}\left|\right];$

$\begin{array}{c}H{(x,t)}^{-}=[H(x+\mathrm{\Δx},t-\mathrm{\Δt})-\frac{a}{\mathrm{gA}}Q(x+\mathrm{\Δx},t-\mathrm{\Δt})]\\ +[\frac{a}{\mathrm{gA}}+\frac{f}{{2\mathrm{gDA}}^2}\mathrm{a\Δt}|Q(x+\mathrm{\Δx},t-\mathrm{\Δ}t\left|\right]Q{(x,t)}^{-}\end{array}---\left(12\right)$

Wherein, ^-represent reverse harmony equation;

Above formula (12) can be reduced to:

H(x,t) ^-＝C ^-+B ^-Q(x,t) ^- （13）

C ^-with representation algebra formula $[H(x+\mathrm{\Δx},t-\mathrm{\Δt})-\frac{a}{\mathrm{gA}}Q(x+\mathrm{\Δx},t-\mathrm{\Δt})],$ B ^-representation algebra formula $[\frac{a}{\mathrm{gA}}+\frac{f}{{2\mathrm{gDA}}^2}\mathrm{a\Δt}|Q(x+\mathrm{\Δx},t-\mathrm{\Δt}\left|\right],$ A/gA can be expressed as the impedance B of pipeline.

By to the solving of above-mentioned equation, can find out in numerous parameters of equation, pipeline impedance B be proportional to pressure wave in fluid along pipe transmmision speed a, be inversely proportional to cross-section of pipeline long-pending.For the pipeline of standard geometry, pipeline section is long-pending to be changed not quite, and the flexible variable effect of pipe thickness and pipeline is larger.The pipeline of take in this example is example, and the coming off of cement lining can cause a certain proportion of tube wall attenuation and elastic modulus loss, once and inside pipe wall is directly exposed in water, corrosion can aggravate gradually and cause pipe thickness to reduce.

The impaired direct result of tube wall is the velocity of wave Speed Reduction of pipe transmmision, and cross-section of pipeline is long-pending can be increased, so pipeline impedance B can reduce.Thus, the variation of pipe thickness and pipe lining can cause the variation of pipeline pressure, and the transient signal reflecting back is changed, and the position of pipeline variation can be determined in the position changing by definite reflected signal.

Based on harmony establishing equation transition model, employing duct length is 5m, time step is the pipeline of 0.0049261s, pipeline physical geometry character comprises pipeline theory diameter, elasticity modulus of materials, the loose ratio of uncle, fluid density and bulk modulus, by measurement point steady state pressure, is measured and is determined pipeline hydraulic boundary condition.After transition model is set up, the pipeline of this 5m length is carried out to trial and error experiment repeatedly, determine the pressure wave interactive signal of prediction, and and the interactive signal comparison of mensuration before.Transition model is considered the hydraulic performance relevant to induction pressure ripple simultaneously, and the pressure versus flow based on measuring or inferring is determined.

In selected pipeline, the variation of velocity of wave has also comprised pipe thickness, elasticity, internal diameter of the pipeline and along the variation of the sectional area of pipe lengths simultaneously.These variations cause pipeline impedance B to change simultaneously, and the baroreflex signal of impact prediction.Afterwards, pressure wave reflection signal process measurement point on pipeline (G, L1, R1) prediction and actual measurement compares the repeatedly trial and error experiment of velocity of wave, the impact of average velocity of wave between the measurement point of describing before this method is not subject to.

In Another application example, the scope that pipeline morphs can be undertaken by the global search step based on full transition model.What Figure 11 represented is the another kind of flow process of determining pipeline range of variation in the present invention.

First be to set up initial transition model, in this example, the pipeline of the foundation of initial transition model based on a segment length 2000m, pipeline is divided into the pipeline section that 400 segment length are 5m, and the parameter of these pipeline sections changes according to required fine degree and computing power.If only need the pipeline variation situation within the scope of nearest 100m be measured, in the situation that not affecting minimum computing power, duct length is got short as much as possible.

Initial transition model is based upon on pipeline physical features and fluid flow basis, and as the optimizing process of initial scheme.In Another Application implementation process, the foundation of initial transition model comprises the preprocessing process according to pipeline variation situation initial estimation.Pipeline situation initial estimation includes but not limited to the following aspects:

Between measurement point, by pulse waveform, analyze or velocity of wave that other forms are definite is estimated

Heterogeneous pass time migration pressure signal

Use Joukowsky pressure formula to derive the funtcional relationship of initial velocity of wave and position

The initial transition model obtaining based on trial and error

Use the above-mentioned preprocess method of mentioning can obtain along the useful velocity of wave of duct orientation (pipe thickness) information, and can reduce the computing time of setting up transition model.For the pipeline of above-mentioned 2000m, be divided into after the pipeline of 400 * 5m, adopt preprocess method, can be reduced to the duct length of 150 * 5m.Initial analysis shows the long pipeline for 5m, according to the velocity of wave of the maximum pressure calculated signals of reflection, is 800m/s.

Figure 12 is the long pipeline section upward pressure ripple interactive signal distribution situation of one section of selected 5m, according to pressure signal, distributes and judges the position that pipeline morphs.The accuracy of preprocessing process can adopt more approaching surveying range or with 150 * 5m pipeline section burst length.

Initial transition model is mainly used for the pressure wave interactive signal of generation forecast and compares with the pressure wave interactive signal of actual measurement, comparison procedure obtains prediction and measured signal difference, and difference size is determined by the least square method of observation signal and the total difference of two squares of simulating signal.Total difference of two squares can be reduced to the difference between objective function and minimum objective function in global search optimizing process.If simulation is less than a certain setting value or reaches minimum with actual measurement difference, this relevant transition model can be defined as scheme transition model so; If simulation is greater than a certain setting value with actual measurement difference, carries out model modification and re-start signal analysis.Method described above is identified as adverse transients model analysis method, and its pressure wave interactive signal that variation produces for different pipe sections pipeline all can be processed.

In the present invention, genetic algorithm (GA) and colony complex evolution algorithm (SCE) are all used to the modification process to transition model, in this case, in transition model, each pipeline section has different velocities of wave, by global search step, determine that one group of velocity of wave can reduce gaging pressure ripple interactive signal difference simultaneously, and determine amended transition model.

By Genetic algorithm searching process, the reflected signal of collecting is processed.First its genetic algorithm parameter of Analysis of Genetic Algorithms process (GA1) arranges as shown in table 2 below, initial velocity of wave is 915m/s, velocity of wave variation range 800-1000m/s, the genetic parameter setting that the second Analysis of Genetic Algorithms process (GA2) is sampled identical, initial velocity of wave is 915m/s, velocity of wave variation range 700-1100m/s.GA1 and GA2 sunykatuib analysis time approximately spend 24 hours.

The setting of table 2 genetic algorithm parameter

Adopt colony's complex evolution algorithm (SCE) analytic process parameter to list in table 3, initial velocity of wave is 915m/s, velocity of wave variation range 700-1100m/s, and need 168 hours computing time.

Table 3 colony complex evolution algorithm parameter arranges

Figure 13 is each pipeline section velocity of wave predicted value variation tendency in 150 pipeline sections, as can be seen from the figure, the result that GA1 and GA2 algorithm obtain changes more remarkable than SCE arithmetic result, be mainly that Another reason is that the genetic algorithm duration is shorter due to the difference of GA algorithm and the setting of SCE algorithm parameter.

The deviation obtaining of GA2 algorithm is obviously large than GA1, and it is mainly that the velocity of wave obtaining with SCE algorithm is relatively stable because the velocity of wave scope that GA2 limits is larger than GA1, and is more or less the same with average velocity of wave.Analysis result relatively finds that SCE algorithm is more reliable to the method for pipeline velocity of wave prediction.

Based on above analysis, with SCE method and average result of calculation method, 150 pipeline section velocities of wave and corresponding pipe thickness are carried out to transition model analysis respectively, result is as shown in figure 14.

From Figure 14, can clearly find out, velocity of wave circumscription is when 700-1100m/s, and pipe thickness range is between 2-9mm, and the pipe thickness obtaining in figure is that the velocity of wave scope of simulating by acquisition with SCE step obtains.

After corresponding relation by SCE analyzer tube wall thickness and simulation velocity of wave, respectively with GA1, GA2 and the pressure wave interactive signal of SCE method simulation and the pressure wave interactive signal of actual measurement compare, and obtain result as shown in figure 15.

As can be seen from the figure, GA2 is similar with SCE process simulation result, but slightly more different than GA1 process.In figure, forward and buffer brake reflected signal can be realized transition model by global search method and entirely simulate, and GA2 and SCE analog result and observed pressure reflected signal meet better.

Figure 16 result shows to adopt same simulation process at another measurement point, can obtain similar analog result equally, and analog result can be mated preferably with actual measurement.

Result shown in Figure 17 is to adopt SCE step (1910 sections) to assess the long duct thickness of 2km, and compares with Ultrasonic Detection (1920 sections) result, by 1930 sections of average velocities of wave that can reflect corresponding different pipe sections in figure, changes.

Compare with reverse transient analysis method, the quantity of information that in figure, the average velocity of wave information (1930 section) corresponding with pipeline section provides is less.For example, in figure, between pile No. 15280-15700m, in the pipeline section interval of correspondence, average velocity of wave is lower, by ultrasonic detecting technology, can obviously determine the damaged situation of this segment pipe, but can not carry out quantitative test to the damaged situation of this segment pipe, reverse transient analysis can obtain the positional information that local variation occurs pipeline section exactly.

Stack by corresponding measurement point time migration pressure wave interactive signal result, can obtain reverse transient analysis and further confirm result.Pressure wave interactive signal shown in Figure 18 and Figure 19 is the stack to Figure 17 result, in Figure 18, surveying pipe thickness reduces, reverse transient analysis result difference between time migration signal and pile No. 15280-15700m is obvious, and Figure 19 has further confirmed this variation relation between result in three.

In sum, patent of the present invention provides technology and the method for a cover system, be mainly used in the detection of localized variation in pipeline conditions, compare (CCTV with traditional detection technique, Ultrasonic Detection), this technological invention does not need to carry out detailed pipe detection, in every instantiation of the present invention, can the pipeline section that localized variation occurs be isolated by dividing pipeline section, and the result obtaining by algorithms of different compares.

In the present invention " transition " can be regarded as a kind of mode that produces pressure wave in pipeline, transition is similar to ducted " water hammer ", no matter is " transition ", sounding or other forms of pressure wave, its occurring principle is all similar.

The technology of the present invention not only can be applicable to water delivery and distributing pipe line, also can be used for other forms of pressure current pipeline, as sewer line, and petroleum pipe line and conveying gas pipeline.The technology of the present invention can be applied but be not limited to the pipeline with Types Below:

-metallic conduit is as cast carbon steel, low carbon steel pipe, ductile iron pipe and stainless-steel tube etc.

-ceramic pipe is as steel essence concrete pipe, cement pipe or vitreum clay pipe

-plastic tube is as pvc pipe, and HDPE manages, cast, glass fiber reinforced plastic tubes and ABS pipeline etc.

In addition, the present invention also can be applicable to the tube wall that above two or more material is mixed to form.

Above specific embodiments of the invention are described.It will be appreciated that, the present invention is not limited to above-mentioned specific implementations, and those skilled in the art can make various distortion or modification within the scope of the claims, and this does not affect flesh and blood of the present invention.

Claims (12)

1. a conveyance conduit hydraulic detection appraisal procedure, is characterized in that, comprises the steps:

Step 1: produce pressure wave in the pipeline fluid along Flows;

Step 2: the interactive signal producing after the local variation of detected pressures ripple and pipeline interacts, wherein, the pressure signal of interactive signal for having an effect and reflect by described pressure wave and the local variation of pipeline, be used for compensating the pressure effect producing due to pipeline fluid, the feature of interactive signal is the change of interactive signal amplitude;

Step 3: by the feature of the interactive signal that receives, determine the tube wall situation after pressure wave contacts with local tube wall;

Step 4: based on interactive signal, determine the scope of the local variation of pipeline in pipeline situation.

2. conveyance conduit hydraulic detection appraisal procedure according to claim 1, it is characterized in that, in described step 1, particularly, along pipeline, in source position, change pipeline pressure and/or change characteristic of fluid, wherein, changing pipeline pressure or change characteristic of fluid is included in source position exhaust fluid and/or stops discharging.

3. conveyance conduit hydraulic detection appraisal procedure according to claim 1, is characterized in that,

Described step 3, specifically comprises the steps:

Step 3.1: transmitting transient pressure wave source;

Step 3.2: pressure wave and pipeline generation reciprocation, and produce interactive signal;

Step 3.3: receive interactive signal;

Step 3.4: set up pipeline transition model, resolve pressure wave interactive signal, determine pipeline situation.

4. conveyance conduit hydraulic detection appraisal procedure according to claim 1, is characterized in that, for the reflection wave of appointment, has the interactive signal corresponding with it, and described step 4 comprises the steps:

Step 4.1 ＇: set up pipeline section transition model;

Step 4.2 ＇: receive the interactive signal after the local variation of pipeline section;

Step 4.3 ＇: determine Joukowsky equation variable parameter;

Step 4.4 ＇: calculate and definite pipeline section range of variation;

Wherein, transition model is set up as follows:

Step I 1: determine pipeline variation type;

Step I 2: manually set pipe leakage amount;

Step I 3: determine pressure-wave emission speed;

Step I 4: build-up pressure ripple pipe transmmision is ruled equation;

Step I 5: transition model tuning.

5. conveyance conduit hydraulic detection appraisal procedure according to claim 1, is characterized in that, improves as follows the intensity of interactive signal:

Steps A: subtract pulse step, is specially: in removal interactive signal, segment pulse is in conjunction with transition wave head;

Step B: low-pass filter step, is specially: utilize the filtrator of low pass bandwidth that the interactive signal by after processing of step A is filtered, the filtering signal of receiving is further removed;

Step C: add pulse step, be specially: the segment pulse of the interactive signal before processing of step A is reintroduced back to the interactive signal after processing by step B, and generates trendless signal.

6. conveyance conduit hydraulic detection appraisal procedure according to claim 1, it is characterized in that, in step 3, by compensate the variation of average velocity of wave can be further the accurate position of pipeline variation, wherein average velocity of wave is defined as: to the corresponding instantaneous celerity of different period pressure waves, by the pressure-wave emission speed to different pipe sections, carry out statistical study, obtain the average velocity of propagating in this type of conduits.

7. conveyance conduit hydraulic detection appraisal procedure according to claim 1, is characterized in that, in step 4, comprises the steps:

-the size that pressure interactive signal is changed is converted into the variation of the local velocity of wave of pressure wave, is specially:

$\mathrm{\ΔH}=-\frac{a}{g}\mathrm{\ΔV}$ Formula (1)

Wherein, Δ H is for specifying reflection wave pressure head to change, and a is pressure wave velocity of propagation along pipeline in fluid, and g is gravity acceleration constant, and Δ V is change in flow size;

-the local velocity of wave of pressure wave is changed with local pipe thickness and sets up corresponding relation, be specially:

$a=\sqrt{\frac{K/\mathrm{\ρ}}{1+(K/E)(D/t)c}}---\left(2\right)$

Wherein, the bulk modulus that K is water, the density that ρ is water, the elastic modulus that E is tube wall, t is pipe thickness, and D is internal diameter of the pipeline, and c is pipeline constraint factor, c=1 when pipeline is flexible interface, c=1-v when pipeline is rigid conduit interface ², v is Poisson ratio, and rigid conduit interface is welding junction or the cement class encapsulant of pipeline outer wall mounting strap saddle type pedestal, and flexible interface is for bearing the pipe joint of a certain amount of axial line displacement and relative angle displacement.

8. a conveyance conduit hydraulic detection evaluating system, is characterized in that, comprises as lower device:

The first pressure wave generator, produces pressure wave for the pipeline fluid along Flows;

The first interactive signal pick-up unit, for detection of the interactive signal producing after pressure wave and the local variation interaction of pipeline, wherein, the pressure signal of interactive signal for having an effect and reflect by described pressure wave and pipeline localized variation, be used for compensating the pressure effect producing due to pipeline fluid, the feature of interactive signal is the change of interactive signal amplitude of variation;

The first data processing equipment, for the feature of the interactive signal by receiving, determines the tube wall situation after pressure wave contacts with local tube wall, and based on interactive signal, determines the scope of the local variation of pipeline in pipeline situation.

9. a delivery fluid line state evaluating method, is characterized in that, comprises the steps:

Step 1: along duct orientation, produce pressure wave in source position;

Step 2: detect a plurality of by pressure wave and the rear interactive signal producing of pipeline localized variation interaction at different monitoring locations, wherein, the pressure signal of interactive signal for having an effect and reflect by described pressure wave and the local variation of pipeline, be used for compensating the pressure effect producing due to pipeline fluid, the feature of interactive signal is the change of interactive signal amplitude of variation; Wherein, detection position comprises source position;

Step 3: the position of determining localized variation in pipeline by the interactive signal time;

Step 4: the degree of the feature judgement pipeline localized variation based on interactive signal.

10. delivery fluid line state evaluating method according to claim 9, is characterized in that, described step 3 comprises the steps:

Step 301: determine that pressure wave is in ducted velocity of propagation;

Step 302: record pressure wave and transmit and receive the mistiming;

Step 303: the distance of calculating pipeline localized variation based on speed time formula;

Step 304: calculate pipeline localized variation position with respect to the position of pressure wave source.

11. delivery fluid line state evaluating method appraisal procedures according to claim 9, it is characterized in that, after transmitting pressure wave and pipeline localized variation interact, produce pressure wave interactive signal, this interactive signal all has corresponding interactive signal intensity to pipeline localized variation degree, based on this reflected signal strength feature, determines pipeline localized variation size.

12. 1 kinds of delivery fluid line state evaluating method evaluating systems, is characterized in that, comprise as lower device:

The second pressure wave generator, for along duct orientation, produces pressure wave in source position;

The second interactive signal pick-up unit, for detect a plurality of interactive signals by producing after pressure wave and the interaction of pipeline localized variation at different monitoring locations, wherein, the pressure signal of interactive signal for having an effect and reflect by described pressure wave and the local variation of pipeline, be used for compensating the pressure effect producing due to pipeline fluid, the feature of interactive signal is the change of interactive signal amplitude of variation; Wherein, detection position comprises source position;

The second data processing equipment, determines the position of localized variation in pipeline by the interactive signal time, and the degree of the judgement of the feature based on interactive signal pipeline localized variation.