CN102779199A - Method for realizing dynamic simulation process of natural gas pipe network conveying system - Google Patents
Method for realizing dynamic simulation process of natural gas pipe network conveying system Download PDFInfo
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Abstract
The invention discloses a method for realizing a dynamic simulation process of a natural gas pipe network conveying system. Relates to the technical field of pipeline systems. The method comprises the following steps: the frog leap strategy separates a hydraulic system and a thermodynamic system; dealing with thermodynamic system instability in a 'windward' format; solving a linear equation system; and obtaining a solving result of the dynamic simulation numerical model of the natural gas pipe network conveying system. The coupling solution of the hydraulic system and the thermodynamic system is stable, short in calculation time and high in solution efficiency.
Description
Technical field
The present invention is a kind of gas distributing system induction system dynamic simulation realization process method.Relate to the piping system technical field.
Background technology
The emulation of gas distributing system is to utilize the mathematical model that rock gas flows in pipeline to describe; It is one group of nonlinear partial differential equations; Academia does not provide the analytic solution that meet the practical applications needs, in engineering, adopts numerical method to find the solution usually.Pipe network emulation comprises static Simulation and transient state emulation two aspects, and static Simulation is the strong instrument that carries out design of pipe networks, is the important evidence of choosing pipe network structure and parameter scheme, and its accuracy directly influences whether safe and reliable and economical rationality of design proposal.Transient state emulation can simulative tube network operation parameter over time; Can be directed against the different processes design proposal; For example peak regulation, pipeline emptying and fracture burst accident carry out transient state and calculate, according to result of calculation; Propose good solution, thereby ensure the efficient scheduling management and in time find and handle burst accident.Gas distributing system induction system dynamic simulation compares with static Simulation that to find the solution difficulty bigger, and range of application is wider.In 2005 " University Of Tianjin's paper " " theoretical analysis of gas distribution system, gas network security and emulation and applied research " to disclose a kind of serve as the steady dynamic simulation theoretical model of gas ductwork under the gentle non-isothermal condition such as basis foundation etc. with three big conservation equations; The result compares and analyzes through the contrast gained; Draw the applicability of its engineering, and then reference is provided for the optimization of gas ductwork.
But at present gas distributing system induction system dynamic simulation procedural implementation method exists waterpower, the unsettled difficult problem of therrmodynamic system Solving Coupled, and computing time is long, it is low to find the solution efficient.
The method of finding the solution the dynamic simulation numerical model commonly used comprises approximate analytical method (linearization) and numerical method two big classes.The processing of approximate analytical method is with the linear partial linearization of the branch of mathematical model, changes into partial differential equations, obtains analytic solution according to initial value then, and linearizing method mainly contains average, proper that interpolate value and least square method.Approximate analytical method mainly be a little that computing velocity is fast, shortcoming is that computational accuracy is relatively poor, is applicable to simulation pipe network operation situation in the long-time scope.Numerical method is the maturation of Along with computer technology and growing up gradually, mainly is method of finite difference, and the principle of this method is to change into difference equation to PDE, finds the solution difference equation with iterative numerical approach then.PDE change into method of Difference Equations and mainly contain method of characteristic, implicit expression center method and Taylor expansion method.The advantage of numerical solution is that computational accuracy is high and calculate more flexibly, and shortcoming is that to find the solution speed fast not as the approximate analysis solution.
For method of characteristic; Non-linear algebraic equation group to each node and the pipe interior net point of system are independently set up corresponding low dimension can turn to the PDE on the pipeline characteristic difference equation, is characterized in need not finding the solution huge Nonlinear System of Equations; Be easy to find the solution; Take less calculator memory, but in order to satisfy the stability of finding the solution, the time level is often obtained very little.Yet; For the gas distributing system system, because the compressibility of gas, it is much littler than the unstable degree that fluid pipeline occurs that it unstable degree occurs; Thereby the time level got for a short time and there is no need, and do not meet the requirement of practical applications to the dynamic simulation time step.
For implicit difference method, consider all nodes and pipe interior net point, set up unified high dimensional nonlinear Algebraic Equation set.Since will be with treating that unknown quantity simultaneous all on the seeking time level gets up to find the solution, the Nonlinear System of Equations that need find the solution is very huge, and finding the solution needs the long time.But this method can guarantee the stability found the solution, and time step can obtain bigger.
Summary of the invention
The objective of the invention is to invent that a kind of waterpower, therrmodynamic system Solving Coupled are stable, computing time is short, find the solution the high gas distributing system induction system dynamic simulation realization process method of efficient.
Gas distributing system induction system dynamic simulation procedural implementation method (see figure 1) of the present invention is:
The strategy that " leapfrogs " separates waterpower, therrmodynamic system;
The format analysis processing of " facining the wind " therrmodynamic system instability;
Solving Linear;
Obtain gas distributing system induction system dynamic simulation numerical model solving result.
" leapfroging " strategy of said Hydraulic Power System and therrmodynamic system is:
Many Hydraulic Power System and therrmodynamic system are coupled of the whole bag of tricks of finding the solution the dynamic simulation numerical model at present commonly used carried out simultaneous solution; In the actual emulation process; The acute variation of the outer boundary of system (pressure, temperature) can cause that serious " sawtooth " phenomenon appears in temperature curve in the solution procedure; Cause the concussion of pressure and flow distribution curve; Even the temperature computation value of physical significance appears not meeting, until result of calculation disperse, system crash.
For " sawtooth " of treatment temperature curve and to the interference problem of Hydraulic Power System to therrmodynamic system; Whole gas distributing system system is divided into Hydraulic Power System and therrmodynamic system is discrete respectively and simultaneous; Each the time step find the solution separately respectively; " extrapolated value " in step imported Hydraulic Power System into and found the solution when earlier thermal parameter being taked preceding two, and the Hydraulic Power System solving result is passed to therrmodynamic system, carries out finding the solution of therrmodynamic system.
It finds the solution the flow process (see figure 2):
Hydraulic Power System and therrmodynamic system are discrete respectively;
Hydraulic Power System and therrmodynamic system are set up original state respectively;
The thermal parameter extrapolated value of therrmodynamic system is handled;
The Hydraulic Power System original state is set up the back and is handled the back acting in conjunction in Hydraulic Power System with the thermal parameter extrapolated value;
Arrive therrmodynamic system behind the Hydraulic Power System; Therrmodynamic system arrives the thermal parameter extrapolated value again and handles;
Finish behind the Hydraulic Power System.
The strategy that " leapfrogs " is alternately found the solution Hydraulic Power System and therrmodynamic system in time; Each energy equation obtains pressure with the front and flow value is the basic calculation temperature, and the temperature value that two time steps " extrapolation " obtain before each Hydraulic Power System is basic calculation pressure and flow; Its advantage replaces a large matrix to find the solution with two less Matrix Solving of scale, has improved computing velocity significantly; Because the special construction of minor matrix can be stored with sparse matrix technology; Although be not subject matter, off-line dynamic simulation numerical model is found the solution still have crucial meaning but fully improve counting yield for the modern computing motor speeds;
Said " facining the wind " format analysis processing therrmodynamic system instability (see figure 3) is:
The instability that basic reason that " sawtooth " appear in curve is therrmodynamic system appears in temperature when Solving Coupled Hydraulic Power System and therrmodynamic system; After " leapfroging " strategy separation waterpower, therrmodynamic system; When increasing computing velocity; Also unsettled therrmodynamic system is separated and focused on, the convergence exponent number of therrmodynamic system on time shaft brought up to 2 rank from 1 rank, greatly improved the stability of therrmodynamic system.
In addition, when the pipeline inner fluid flow direction changed, temperature curve " sawtooth " can occur equally, thereby causes the collapse of Hydraulic Power System.This is because in finding the solution the dynamic simulation system process; The very important point is speed and a direction of confirming that flow field information is propagated; So that numeric format is consistent with the physical property that flows; Otherwise the result who obtains sizable concussion can occur near rough zone, even the result who obtains is unacceptable.In order to address the above problem, introduced " facining the wind " form; Upstreame scheme is to confirm the difference orientation according to the characteristic velocity direction in flow field; Meet the perturbation wave propagation law physically; This obtains very little restriction for satisfied stability requires time horizon to have overcome method of characteristic simultaneously, and adopts central difference to cause the deficiency of solving result concuss because of ignoring the flowing information direction of propagation.
In gas distributing system induction system dynamic simulation numerical model is found the solution specifically; Adopt the piece-wise constant function to approach temperature curve; In the direction of each computing node, decide the interpolation form (regressive interpolation and forward interpolation) of the derivative of temperature to guarantee it is to carry out interpolation processing all the time along the mobile direction of fluid according to flow velocity; This method has solved the stability problem at the heat equation that flows to not timing effectively.
Said Solving Linear is topological structure (see figure 4) and the characteristic according to pipe network; NLS to forming is carried out topological sorting; Make that the Jacobian matrix that forms is the block diagonal angle sparse matrix of a band edge; Adopt the Harwell-Boeing form to carry out carrying out exchanges data with the Solving Linear device, inner pretreated consuming time when finding the solution with minimizing, improve on the whole and find the solution efficient; Practice shows, for the matrix of 30,000 dimensions, and its linear solution consuming time at 10 Milliseconds.
The present invention proposes is applicable to and has overcome waterpower, the unsettled difficult problem of therrmodynamic system Solving Coupled by gas distributing system induction system dynamic simulation numerical model method for solving, shortens computing time, improves and find the solution efficient, satisfies application requirements in the actual production.
Description of drawings
Fig. 1 dynamic simulation procedural implementation method process flow diagram
Fig. 2 tactful synoptic diagram that " leapfrogs "
Fig. 3 tactful synoptic diagram that facings the wind
Fig. 4 pipe network topology diagram
Embodiment
Embodiment. embodiment of the present invention is described and the present invention is further described with this example.This example is that gas distributing system induction system dynamic simulation numerical model is found the solution the efficient instance, and its flow process is as shown in Figure 1:
The strategy that " leapfrogs " separates waterpower, therrmodynamic system;
The format analysis processing of " facining the wind " therrmodynamic system instability;
Solving Linear;
Obtain gas distributing system induction system dynamic simulation numerical model solving result.
For the counting yield of verifying the gas distributing system dynamic simulation procedural implementation method that the present invention proposes and the accuracy of finding the solution; As embodiment, carried out dynamic simulation result contrast with domestic certain gas distributing system with foreign commercial pipeline simulation software Stoner Pipeline Simulator (SPS) (gas component, ground temperature distribute, pressure is set off in first battle, terminal enters the station pressure, compressor and valve state) under same condition.
Long defeated gas distributing system comprises 3 sources of the gas, 7 compressor stations, 6 defeated stations of branch, 32 valve chambers, 45 pipeline sections, main line length 1568km among the embodiment.Be without loss of generality, provide the topological structure at one of them compressor station, 2 valve chambers, 1 defeated station of branch at this, as shown in Figure 4.
Begin to start the operation dynamic simulation from zero flow, as a child system was basicly stable when simulation time accumulative total reaches 16, and gas distributing system intake condition and outlet parameter result of calculation contrast situation are respectively shown in table 1 and table 2:
The contrast of table 1 embodiment pipe network start-up course emulation intake condition result of calculation
Table 2 embodiment pipe network start-up course outlet parameter simulation calculation result contrast
Annotate: S representes on the hurdle SPS result of calculation, and R representes that the present invention proposes implementation method result of calculation, and E representes relative error
Comparison result from table, the result of calculation goodness of fit of the result of calculation of this software and SPS is than higher, and wherein the average relative error of pressure is in 3%, and the average relative error of flow is in 3.5%, and the average relative error of temperature is in 1%.The counting yield aspect: in dominant frequency is 2.6GHZ, in save as on the PC of 2G, when computing node was 2000, the dynamic simulation single step was calculated average out to consuming time 0.210 second, was linear growth with interstitial content in the analogue system.
This example is through on probation, and it has overcome waterpower, the unsettled difficult problem of therrmodynamic system Solving Coupled, shortens computing time, improves and find the solution efficient, satisfies application requirements in the actual production.
Claims (4)
1. gas distributing system induction system dynamic simulation realization process method is characterized in that this method is:
The strategy that " leapfrogs " separates waterpower, therrmodynamic system;
The format analysis processing of " facining the wind " therrmodynamic system instability;
Solving Linear;
Obtain gas distributing system induction system dynamic simulation numerical model solving result.
2. gas distributing system induction system dynamic simulation realization process method according to claim 1 is characterized in that " leapfroging " strategy of said Hydraulic Power System and therrmodynamic system is:
Whole gas distributing system system is divided into Hydraulic Power System and therrmodynamic system is discrete respectively and simultaneous; Each the time step find the solution separately respectively; " extrapolated value " in step imported Hydraulic Power System into and found the solution when earlier thermal parameter being taked preceding two; The Hydraulic Power System solving result is passed to therrmodynamic system, carry out finding the solution of therrmodynamic system;
It finds the solution flow process:
Hydraulic Power System and therrmodynamic system are discrete respectively;
Hydraulic Power System and therrmodynamic system are set up original state respectively;
The thermal parameter extrapolated value of therrmodynamic system is handled;
The Hydraulic Power System original state is set up the back and is handled the back acting in conjunction in Hydraulic Power System with the thermal parameter extrapolated value;
Arrive therrmodynamic system behind the Hydraulic Power System; Therrmodynamic system arrives the thermal parameter extrapolated value again and handles;
Finish behind the Hydraulic Power System.
The strategy that " leapfrogs " is alternately found the solution Hydraulic Power System and therrmodynamic system in time; Each energy equation obtains pressure with the front and flow value is the basic calculation temperature, and the temperature value that two time steps " extrapolation " obtain before each Hydraulic Power System is basic calculation pressure and flow; Store with sparse matrix technology.
3. gas distributing system induction system dynamic simulation realization process method according to claim 1 is characterized in that said " facining the wind " format analysis processing therrmodynamic system instability is:
Confirm the difference orientation according to the characteristic velocity direction in flow field; In gas distributing system induction system dynamic simulation numerical model is found the solution; Adopt the piece-wise constant function to approach temperature curve; In the direction of each computing node according to flow velocity, decide the interpolation form of temperature derivative, the direction that flows along fluid is all the time carried out interpolation processing.
4. gas distributing system induction system dynamic simulation realization process method according to claim 1; It is characterized in that said Solving Linear is: according to the topological structure and the characteristic of pipe network; NLS to forming is carried out topological sorting; Make that the Jacobian matrix that forms is the block diagonal angle sparse matrix of a band edge, adopt the Harwell-Boeing form to carry out carrying out exchanges data with the Solving Linear device.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103955186A (en) * | 2014-04-22 | 2014-07-30 | 中国石油大学(北京) | Natural gas pipe network pipe flow state parameter determining method and device |
| CN103970029A (en) * | 2014-05-14 | 2014-08-06 | 中国石油大学(华东) | Gas pipeline dynamic simulation method based on pulse response sequences |
| CN106707795A (en) * | 2016-12-30 | 2017-05-24 | 贵州大学 | Real-time simulation model and system of natural gas pipeline network and power grid coupling system |
| CN107977513A (en) * | 2017-11-30 | 2018-05-01 | 北京石油化工学院 | A kind of temperature predicting method when natural gas dynamic flows in gas distributing system based on route searching |
| CN109754109A (en) * | 2017-11-08 | 2019-05-14 | 中国石油天然气股份有限公司 | Method and device for determining natural gas pipe network operation scheme |
| CN111177892A (en) * | 2019-12-11 | 2020-05-19 | 中电普信(北京)科技发展有限公司 | Distributed simulation system |
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Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103955186A (en) * | 2014-04-22 | 2014-07-30 | 中国石油大学(北京) | Natural gas pipe network pipe flow state parameter determining method and device |
| CN103955186B (en) * | 2014-04-22 | 2016-08-24 | 中国石油大学(北京) | Gas distributing system pipe flow condition parameter determination method and device |
| CN103970029A (en) * | 2014-05-14 | 2014-08-06 | 中国石油大学(华东) | Gas pipeline dynamic simulation method based on pulse response sequences |
| CN103970029B (en) * | 2014-05-14 | 2017-03-29 | 中国石油大学(华东) | A kind of Gas Pipeline Dynamic Simulation method based on Least square estimation |
| CN106707795A (en) * | 2016-12-30 | 2017-05-24 | 贵州大学 | Real-time simulation model and system of natural gas pipeline network and power grid coupling system |
| CN106707795B (en) * | 2016-12-30 | 2023-06-06 | 贵州大学 | Real-time simulation model and system of natural gas pipe network and power grid coupling system |
| CN109754109A (en) * | 2017-11-08 | 2019-05-14 | 中国石油天然气股份有限公司 | Method and device for determining natural gas pipe network operation scheme |
| CN107977513A (en) * | 2017-11-30 | 2018-05-01 | 北京石油化工学院 | A kind of temperature predicting method when natural gas dynamic flows in gas distributing system based on route searching |
| CN107977513B (en) * | 2017-11-30 | 2021-04-16 | 北京石油化工学院 | Natural gas dynamic flow temperature prediction method based on path search |
| CN111177892A (en) * | 2019-12-11 | 2020-05-19 | 中电普信(北京)科技发展有限公司 | Distributed simulation system |
| CN111177892B (en) * | 2019-12-11 | 2023-05-02 | 中电普信(北京)科技发展有限公司 | Distributed simulation system |
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