CN-122021482-A - Pressurized pipeline water filling process numerical simulation method with air valve, equipment and medium

CN122021482ACN 122021482 ACN122021482 ACN 122021482ACN-122021482-A

Abstract

The invention discloses a numerical simulation method, equipment and medium for a water filling process of a pressurized pipeline with an air valve, belonging to the technical field of long-distance pressurized water delivery system engineering, wherein the method comprises the following steps: by constructing a coupling control equation of three integration of pipeline water flow, in-pipe air mass and air valve air inlet and exhaust, and combining a gas-liquid interface tracking algorithm suitable for the full transition flow and a refined air valve dynamic model, the accurate numerical simulation of the whole process from empty pipe filling to full pipe running of the pressurized pipeline is realized. By adopting the numerical simulation method, the numerical simulation equipment and the numerical simulation medium for the water filling process of the pressurized pipeline with the air valve, the simulation precision of the water filling hydraulic parameters is improved, the calculation stability and the engineering applicability under complex working conditions are improved, the dangerous working conditions such as air blockage, pressure abnormality and water hammer can be accurately identified, and reliable support is provided for the design, the safety evaluation and the protection optimization of the water filling scheme of the long-distance water conveying pipeline.

Inventors

LI TAO
YANG XIAOCHUN
WANG TAO
SONG TAO

Assignees

安徽省水利水电勘测设计研究总院股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260416

Claims (10)

1. The method for simulating the water filling process of the pressurized pipeline with the air valve is characterized by comprising the following steps of: S1, acquiring pipeline geometric topology parameters, fluid physical parameters, air valve working parameters and initial and boundary conditions, performing one-dimensional mesh subdivision on a pipeline calculation domain, and generating and outputting a standardized parameter data set, discrete mesh information and initial flow field parameters; S2, receiving S1 output data, and establishing a closed coupling equation set containing water flow, air mass and air valve dynamic flow equations based on a one-dimensional bright full transition flow theory, a gas thermodynamic rule and air valve dynamic characteristics; S3, receiving the coupling equation set output by the S2, completing space and time dispersion by adopting a weighted implicit format, adaptively determining a calculation time step length according to a Brownian stability criterion, and generating and outputting a discrete algebraic equation set and a coefficient matrix; S4, receiving the discrete format, the time step and the flow field physical quantity at the last moment output by the S3, calculating and updating the gas-liquid interface position, judging the flow state type based on the pipe section fullness, outputting the gas-liquid interface and the flow state parameters, and synchronously feeding back to the S2 to update the coupling model; S5, receiving air mass pressure, interface position and flow state parameters output by the S4, calculating air valve real-time air inlet and outlet flow by combining a valve opening and closing hysteresis model, updating air mass state, correcting nonlinear boundary conditions, and outputting corrected boundary and air mass parameters; S6, receiving the boundary condition and the discrete equation set output by the S5, and synchronously iterating the full-field coupling variable by adopting a Newton-Lapherson method and judging the convergence, wherein the convergence is that the flow field and the air mass parameters are output to a post-processing step, and the residual parameters are returned to the S3 for adjusting the time step and recalculating if the flow field and the air mass parameters are not converged; S7, receiving the time sequence flow field and the air mass motion parameters output in the S6, identifying overpressure, negative pressure and air blockage dangerous working conditions in the water filling process according to a preset safety threshold, and outputting simulation results and engineering support data.
2. The method for numerical simulation of water filling process of pressurized pipeline with air valve according to claim 1, wherein in S1, the geometric topological parameters of the pipeline include pipeline segment number and pipeline segment length Pipe diameter D and pipeline bottom slope Roughness of pipe wall The modulus of elasticity E of the pipe wall; the air valve working parameters comprise air valve installation position and valve port effective flow area Threshold value of on-off critical pressure On-off response time constant ; The initial working condition is set as the initial pressure in the pipeline Initial flow rate And the whole area is inflated, wherein, Is at atmospheric pressure, unit 。
3. The method of numerical simulation of a pressurized pipe water filling process with an air valve according to claim 2, wherein the water flow control equation in S2 comprises a water flow continuity equation: ; In the formula, Is the area of the pipeline flowing through, unit ; Is time unit ; Is the flow rate of water in the pipeline, unit ; Is the axial space coordinate of the pipeline, unit ; Equation of water flow: ; In the formula, Is the acceleration of gravity, unit ; Is the pressure head of water flow in the pipeline ; The gradient of the pipeline edge Cheng Mazu is adopted, and no unit exists; the air mass control equation includes the air mass conservation equation: ; In the formula, Is the mass of air mass in the tube ; Is the mass flow rate of air inlet and outlet of air valve, unit Positive values indicate exhaust and negative values indicate make-up; and the state equation of the air mass variable process: ; In the formula, Is the pressure of air mass in the tube ; Is the volume of air mass in the tube ; Is a gas polytropic index without units; Is a constant; the dynamic flow equation of the air valve is as follows: ; In the formula, The flow coefficient which is adaptively changed along with the ratio of the air mass to the atmospheric pressure is free of units; Is the effective flow area of the valve port of the air valve, and the unit ; Is the density of gas in the tube 。
4. A method of modeling a pressurized line fill process with air valve as defined in claim 3 wherein in S3, time-discrete is performed in PREISSMANN-weighted implicit format, expressed as: ; In the formula, The physical quantity to be discretized is a unit-free physical quantity; the weighting coefficient is a weighting coefficient, no unit exists, and the value range is 0.5-1.0; In time steps, units ; Calculating the node number for the space without units; numbering time steps without units; The numerical calculation meets the condition of the stability constraint of the kurroa number: ; In the formula, The number is the Brownian number and has no unit; Is the wave velocity of water hammer ; For space step length, unit ; And adaptively adjusting the time step by combining constraint of the adaptive time step calculation type, which is expressed as follows: ; In the formula, For the next time step, units ; The safety coefficient is zero, the unit is not available, and the value range is 0.5-0.8; For maximum allowable time step, units 。
5. The numerical simulation method for the water filling process of the pressurized pipeline with the air valve according to claim 4, wherein in the step S4, a gas-liquid interface propulsion speed calculation formula is as follows: ; In the formula, Is the first Gas-liquid interface propulsion speed of individual air masses, unit ; Is the first Water flow rate of each space node, unit ; Is the first Water passing area of each space node, unit ; The interface position updating formula step by step time is as follows: ; In the formula, Is the first Time step Interfacial space coordinates of individual air masses, units ; Is the first Time step Interfacial space coordinates of individual air masses, units ; Is the first Time step of time step, unit ; The calculation formula of the pipe section fullness is as follows: ; In the formula, Is the first The pipe section fullness of each space node is free of units, and the value range is 0-1; Is the area of the full pipe flow of the pipeline, and the unit ; Based on pipe section fullness The adaptation distinguishes between pressureless flow, transitional flow and pressured flow.
6. The numerical simulation method for the water filling process of the pressurized pipeline with the air valve according to claim 5, wherein in the step S5, the criterion formula of opening and closing the air valve is as follows: ; ; In the formula, Is the pressure of air mass in the tube at a certain moment ; Is the threshold value of the opening and closing of the air valve, and the unit ; As the deviation of pressure threshold value, unit The valve is used for avoiding frequent opening and closing of the valve; is the opening and closing response time constant of the air valve, unit ; The valve is the relative opening of the air valve, no unit exists, the value range is 0-1, 0 represents full closing, and 1 represents full opening; the calculation formula of the mass increment of the air mass is as follows: ; In the formula, In units of mass increment of air mass in a certain time step ; The air valve is used for feeding and discharging air in real time, unit (B) ; For the current time step, units And updating the mass, volume and pressure parameters of the air mass according to the inlet and outlet air flow.
7. The method for numerical simulation of a pressurized pipeline water filling process with an air valve according to claim 6, wherein in S6, a system of discrete equations is solved using a newton iterative format: ; In the formula, Is a jacobian matrix without units; The correction vector is a correction vector of the physical quantity to be solved, and no unit exists; The residual vector is an equation set residual vector, and no unit exists; The global convergence residual takes an infinite norm of a physical quantity relative to the residual as a convergence judgment standard, and is expressed as: ; In the formula, Is an infinite norm of the residual vector, and has no unit; is the first The physical quantity to be solved of the secondary iteration is free of units; is the first The physical quantity to be solved of the secondary iteration is free of units; the convergence accuracy is preset, and no unit exists.
8. The method for simulating the water filling process of a pressurized pipeline with an air valve according to claim 7, wherein in S7, the overpressure condition judgment is expressed as follows: ; In the formula, Is the first Pressure in pipeline of each space node unit ; Allowable pressure for pipeline design, unit ; ; In the formula, Minimum safety pressure for pipeline ; Judging the air blocking working condition as the interface propulsion speed And pipe section fullness Judging the air blocking working condition, wherein, Is critical fullness of air block, and has no unit.
9. A computer device comprising a processor for coupling with a memory, reading and executing instructions and/or program code in the memory to perform the method of any of claims 1-8.
10. A computer readable medium, characterized in that the computer readable medium stores computer program code which, when run on a computer, causes the computer to perform the method according to any of claims 1-8.

Description

Pressurized pipeline water filling process numerical simulation method with air valve, equipment and medium Technical Field The invention belongs to the technical field of long-distance pressurized water delivery system engineering, and particularly relates to a numerical simulation method, equipment and medium for a pressurized pipeline water filling process with an air valve. Background The long-distance pressurized water pipeline is widely applied to cross-river water diversion projects, town water supply networks, water conservancy junction pressure water diversion systems and industrial circulating water conveying systems. Under the working conditions of first water supply, rehydration after maintenance, hydrostatic test, emergency water supply and the like of the pipeline, the interior of the pipeline is initially filled with air, and water flow can push air in the pipeline to move and compress in the water filling process, if the air cannot be smoothly discharged through an air valve, air blocking, local high pressure, negative pressure and even liquid column bridging water hammer are extremely easy to form. Because of the limitations of high cost, long period, difficult reproduction of dangerous working conditions and the like in the physical model test, numerical simulation has become a core technical means for designing a water filling scheme of a pipeline, evaluating safety and protecting water hammer. However, the prior art has the defects that the simulation precision of the pressurized pipeline water filling numerical simulation technology is low, the actual deviation of the pressurized pipeline water filling numerical simulation technology and the engineering is large, most models only perform independent calculation on water flow, strong coupling solution of water flow, air mass in a pipe and air inlet and outlet of an air valve is not realized, meanwhile, the air valve model is simplified by adopting a fixed flow coefficient and the like, the air-liquid interface movement under the full water filling flow state cannot be accurately tracked, and the actual hydraulic characteristics of pipeline water filling are difficult to truly reflect. Secondly, the existing numerical algorithm is difficult to consider both precision and stability, numerical oscillation and calculation divergence problems are easy to occur in pressure abrupt change and gas-liquid junction areas, and the numerical algorithm can only adapt to simple straight pipe scenes, is poor in universality of complex pipeline systems with multi-hump, variable gradient and multi-air valve combined arrangement, lacks matched program execution schemes and storage media, and is insufficient in engineering floor and software integration capability. In addition, the existing simulation method cannot accurately identify dangerous working conditions such as air blockage, pressure abnormality, water hammer and the like in the water filling process, simulation results are difficult to effectively guide water filling debugging, air valve arrangement and water hammer protection scheme design, and safety risk prejudging capability of pipeline water filling operation is insufficient. Thus, a new method is needed. Disclosure of Invention The invention aims to provide a numerical simulation method, equipment and medium for the water filling process of a pressurized pipeline with an air valve, the method improves the simulation precision of water filling hydraulic parameters, improves the calculation stability and engineering applicability under complex working conditions, can accurately identify dangerous working conditions such as air blockage, pressure abnormality, water hammer and the like, and provides reliable support for the design, safety evaluation and protection optimization of the water filling scheme of a long-distance water pipeline. In order to achieve the above purpose, the invention provides a method, a device and a medium for simulating the water filling process of a pressurized pipeline with an air valve, which comprises the following steps: S1, acquiring pipeline geometric topology parameters, fluid physical parameters, air valve working parameters and initial and boundary conditions, performing one-dimensional mesh subdivision on a pipeline calculation domain, and generating and outputting a standardized parameter data set, discrete mesh information and initial flow field parameters; S2, receiving S1 output data, and establishing a closed coupling equation set containing water flow, air mass and air valve dynamic flow equations based on a one-dimensional bright full transition flow theory, a gas thermodynamic rule and air valve dynamic characteristics; S3, receiving the coupling equation set output by the S2, completing space and time dispersion by adopting a weighted implicit format, adaptively determining a calculation time step length according to a Brownian stability criterion, and generating and outputting a discrete algebraic