Transient flow identification method, device, equipment, medium and product

Abstract

The invention discloses a transient flow identification method, device and equipment, a medium and a product, and relates to the technical field of pipeline detection. The method comprises the steps of determining a friction resistance coefficient of a target pipeline based on measurement pressure when an inflow area and an outflow area of the target pipeline are in a steady state, steady-state flow data of the target pipeline and pipeline parameters; determining the discrete distance of the target pipeline based on the pipeline parameters of the target pipeline; based on the pipeline parameters, the friction resistance coefficient and the discrete distance of the target pipeline, by taking the measured pressure as a boundary condition, constructing a transient flow characteristic propagation equation of the target pipeline through a characteristic line method; on the basis of the transient flow characteristic propagation equation, transient flow characteristic information of all positions in the target pipeline at all moments is obtained; and constructing a transient flow characteristic field of the target pipeline based on the transient flow characteristic information of each position in the target pipeline at each moment. According to the invention, the accuracy of transient current identification can be significantly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of pipeline detection, and particularly relates to a transient flow identification method, device, equipment, medium and product. BACKGROUND

[0002] As a common hydraulic phenomenon in pipeline operation, the transient flow is mainly caused by the change of fluid flow rate in the pipeline system. When the fluid flow rate in the pipeline changes sharply, the internal pressure of the pipeline will rise sharply, and even cause a pipe burst accident in severe cases, which seriously threatens the safe and stable operation of the pipeline system. Therefore, it is crucial to monitor the internal pressure of the pipeline.

[0003] At present, in the field of pipeline pressure monitoring, the commonly used technical method is to reasonably arrange high-frequency pressure sensors inside the pipeline. With the help of these high-frequency pressure sensors, the pressure data of the pipeline can be obtained, thereby providing a basis for transient flow identification and helping us better understand the pressure change of the pipeline under different working conditions.

[0004] However, the transient flow has obvious space-time characteristics, and the pressure and flow rate in the pipeline will change rapidly with time and space. If only relying on the pressure data collected by part of the monitoring points, the change rule of the transient flow process cannot be fully and completely presented. Since the obtained pressure data is incomplete, the result accuracy of the transient flow identification based on these data is often poor. SUMMARY

[0005] The embodiments of the application provide a transient flow identification method, device, equipment, medium and product, which can significantly improve the accuracy of transient flow identification.

[0006] In a first aspect, the embodiments of the application provide a transient flow identification method, which comprises: determining a friction factor of a target pipeline based on measured pressure when an inflow region and an outflow region of the target pipeline are in a steady state, steady flow data of the target pipeline, and pipeline parameters; and determining a dispersion distance of the target pipeline based on the pipeline parameters of the target pipeline; constructing a transient flow characteristic propagation equation of the target pipeline by a method of characteristic based on the pipeline parameters, the friction factor and the dispersion distance of the target pipeline, and taking the measured pressure as a boundary condition; the transient flow characteristic propagation equation is used to represent the change characteristics of pressure and flow rate with time and space in the target pipeline; obtaining transient flow characteristic information of each position in the target pipeline at each time based on the transient flow characteristic propagation equation, the transient flow characteristic information comprising at least one of pressure and flow rate; constructing a transient flow characteristic field of the target pipeline based on the transient flow characteristic information of each position in the target pipeline at each time; and the transient flow characteristic field of the target pipeline is used for transient flow identification of the target pipeline.

[0007] Further, the application further proposes that the pipeline parameters include the length and diameter of the target pipeline; Based on the measured pressure when the inflow region and the outflow region of the target pipeline are in a steady state, the steady-state flow data of the target pipeline, and the pipeline parameters, the method further comprises: Subtracting the measured pressure when the outflow region of the target pipeline is in a steady state from the measured pressure when the inflow region of the target pipeline is in a steady state to obtain a hydraulic gradient value of the target pipeline; Based on the hydraulic gradient value, the steady-state flow data, the length and diameter of the target pipeline, the method further comprises: ; Wherein, is used to represent the hydraulic gradient value, is used to represent the sign function, v is used to represent the steady-state flow data, L is used to represent the length of the target pipeline, D is used to represent the diameter of the target pipeline, and g is used to represent the acceleration of gravity, is used to represent the friction factor of the target pipeline.

[0008] Further, the application further proposes that the pipeline parameters include the length and diameter of the target pipeline; Based on the pipeline parameters of the target pipeline, the method further comprises: Dividing the ratio of the length of the target pipeline to the measured wave speed by the sampling time interval of the measured pressure to obtain a theoretical dispersion number; Downwardly rounding the theoretical dispersion number to obtain an actual dispersion number; Dividing the length of the target pipeline by the actual dispersion number to obtain the dispersion distance of the target pipeline.

[0009] Further, the application further proposes that, before determining the friction factor of the target pipeline based on the measured pressure when the inflow region and the outflow region of the target pipeline are in a steady state, the steady-state flow data of the target pipeline, and the pipeline parameters, the method further comprises: Based on the preset frequency, collecting transient flow characteristic information of the target pipeline; Subtracting the second transient flow characteristic information of the target pipeline at the second time from the first transient flow characteristic information of the target pipeline at the first time to obtain a characteristic information difference value of the target pipeline; the second time is before the first time and is separated from the first time by N collection times, and N is a positive integer; In the case where the characteristic information difference value is less than a preset steady-state threshold, it is determined that the target pipeline is in a steady state at the first time.

[0010] Further, the application also proposes that, based on the pipe parameter of the target pipe, the friction coefficient and the discrete distance of the target pipe, a transient flow characteristic propagation equation of the target pipe is constructed by the method of characteristic line taking the measured pressure as a boundary condition, including: Based on the pipe parameter of the target pipe and the friction coefficient of the target pipe, a transient flow mass conservation equation and a transient flow momentum conservation equation of the target pipe are constructed; Based on the target wave speed of the target pipe and the cross-sectional area of the target pipe, a characteristic parameter of the target pipe is determined; the target wave speed is a measured wave speed measured for the target pipe, or a corrected wave speed corrected based on the discrete distance of the target pipe; Based on the characteristic parameter of the target pipe, the transient flow mass conservation equation and the transient flow momentum conservation equation are linearly combined to obtain a characteristic line equation; Based on the discrete distance of the target pipe, the characteristic line equation is discretized to obtain a transient flow characteristic propagation equation of the target pipe.

[0011] Further, the application also proposes that, based on the target wave speed of the target pipe and the cross-sectional area of the target pipe, a characteristic parameter of the target pipe is determined, including: The discrete distance of the target pipe is divided by the sampling time interval of the measured pressure to obtain a corrected wave speed; The product of the cross-sectional area of the target pipe and the gravitational acceleration is divided by the corrected wave speed to obtain a target calculation result; Based on the target calculation result, the characteristic parameter of the target pipe is determined.

[0012] The second aspect of the embodiment of the application provides a transient flow identification device, which comprises: A parameter determination module is configured to determine a friction coefficient of a target pipe based on measured pressures when inflow and outflow areas of the target pipe are in a steady state, steady-state flow data of the target pipe and a pipe parameter, and determine a discrete distance of the target pipe based on the pipe parameter of the target pipe; An equation construction module is configured to construct a transient flow characteristic propagation equation of the target pipe by the method of characteristic line based on the pipe parameter of the target pipe, the friction coefficient and the discrete distance of the target pipe, taking the measured pressure as a boundary condition; the transient flow characteristic propagation equation is used to represent the variation characteristics of pressure and flow in the target pipe with time and space; An information acquisition module is configured to acquire transient flow characteristic information of each position in the target pipe at each time based on the transient flow characteristic propagation equation, the transient flow characteristic information including at least one of pressure and flow; A characteristic field construction module is configured to construct a transient flow characteristic field of the target pipe based on the transient flow characteristic information of each position in the target pipe at each time; the transient flow characteristic field of the target pipe is used for transient flow identification of the target pipe.

[0013] A third aspect of the embodiments of this application provides an electronic device, the device comprising: a memory and a program or instructions stored in the memory and executable on a processor, wherein when the program or instructions are executed by the processor, they implement the transient flow identification method provided in any aspect of the embodiments of this application described above.

[0014] A fourth aspect of the embodiments of this application provides a readable storage medium on which a program or instructions are stored, and when the program or instructions are executed by a processor, they implement the transient flow identification method provided by any aspect of the embodiments of this application described above.

[0015] A fifth aspect of the embodiments of this application provides a computer program product in which instructions, when executed by a processor of an electronic device, cause the electronic device to perform the transient flow identification method provided in any aspect of the embodiments of this application described above.

[0016] The transient flow identification method provided in this application determines the friction coefficient of the target pipeline based on the measured pressure in the inflow and outflow regions of the target pipeline under steady-state conditions, the steady-state flow rate data of the target pipeline, and the pipeline parameters. It also determines the discrete distance of the target pipeline based on the pipeline parameters. Because the data is relatively stable and reliable under steady-state conditions, it can provide accurate hydraulic fundamental data for subsequent analysis, accurately reflecting the basic characteristics of the pipeline. Then, the transient flow characteristic propagation equation constructed based on the pipeline parameters, friction coefficient, and discrete distance of the target pipeline can effectively characterize the spatiotemporal variation characteristics of pressure and flow rate in the pipeline, fully considering the spatiotemporal characteristics of transient flow. Finally, the transient flow characteristic field constructed based on this transient flow characteristic propagation equation can comprehensively characterize the pressure and / or flow rate distribution at various locations of the target pipeline at various times, no longer limited to the limited data from some monitoring points. This overcomes the deficiency that data from only some monitoring points cannot fully present the changing laws of the transient flow process, thereby significantly improving the accuracy of transient flow analysis. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating a transient flow identification method provided in one embodiment of this application; Figure 2 This is a schematic diagram of the layout of a pressure measuring device and a flow measuring device provided in one embodiment of this application; Figure 3 This is a schematic diagram of a transient flow characteristic field provided in one embodiment of this application; Figure 4 This is a schematic diagram of the structure of a transient flow identification device provided in one embodiment of this application; Figure 5 This is a schematic diagram of the structure of a transient flow identification device provided in one embodiment of this application. Detailed Implementation

[0019] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0020] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0021] It should be noted that the acquisition, storage, use, and processing of data in the technical solution of this application all comply with the relevant provisions of national laws and regulations.

[0022] It should be noted that in the embodiments of this application, certain software, components, models and other existing solutions in the industry may be mentioned. These should be regarded as exemplary and are only intended to illustrate the feasibility of implementing the technical solution of this application. However, it does not mean that the applicant has used or necessarily used the solution.

[0023] In traditional pipeline transient flow monitoring methods, the deployment of high-frequency pressure sensors is limited by cost and installation conditions, typically only setting up a limited number of monitoring points at the beginning and end of the pipeline and key nodes. Due to the nonlinear propagation characteristics of transient flow, its pressure and flow waves are affected by friction and inertia during propagation, resulting in complex spatiotemporal coupling effects. Point-based monitoring methods struggle to capture waveform distortion and energy attenuation of pressure waves along their propagation path, leading to spatial data gaps when reconstructing the transient flow characteristic field.

[0024] For example, in long-distance pipeline systems, when a terminal valve closes rapidly, triggering a water hammer effect, pressure waves propagate backward along the pipeline at the speed of sound. Existing monitoring methods can only acquire the initial impact peak recorded by the pressure sensor at the beginning and the reflected wave signal captured by the sensor at the end, but cannot acquire the transient pressure gradient distribution in the pressure wave superposition region in the middle section of the pipeline. This data gap makes it difficult for transient flow models based on limited monitoring points to accurately describe the attenuation law of pressure waves along the pipeline axis.

[0025] Faced with the aforementioned problems, this application first recognized that traditional point-based monitoring methods cannot acquire complete spatiotemporal data of transient flow fields. To address this issue, two improvement directions were explored: one is to increase sensor density to obtain more monitoring point data, but this is limited by cost and installation feasibility; the other is to construct a mathematical model based on limited monitoring data to derive the spatiotemporal distribution of the transient flow field. Analysis revealed that the former is difficult to implement in long-distance pipelines, while the latter requires overcoming the dependence of existing methods on discrete monitoring points. Further research found that transient flow propagation follows the conservation laws of fluid mechanics, and its pressure and flow rate changes can be continuously described in the spatiotemporal dimensions using the method of characteristics. Based on this, this application shifts to establishing dynamic equations that can integrate pipeline physical parameters and boundary conditions, and mathematically inverting the complete spatiotemporal characteristics of the transient flow field.

[0026] In this regard, such as Figure 1 As shown, this application provides a flowchart of a transient flow identification method. This transient flow identification method can be applied to various systems or devices with data processing and analysis capabilities, such as transient flow identification devices or transient flow identification equipment.

[0027] The transient flow identification method may include the following steps S101 to S104: S101, based on the measured pressure in the inflow and outflow regions of the target pipeline when they are in steady state, the steady-state flow data of the target pipeline, and the pipeline parameters, determine the friction coefficient of the target pipeline; based on the pipeline parameters of the target pipeline, determine the discrete distance of the target pipeline.

[0028] In this step, the target pipeline is the specific object targeted by the entire method for constructing transient flow characteristic fields. It can be an oil pipeline or gas pipeline in industrial production, or a water pipe in an urban water supply system, etc., and has specific geometric shapes, dimensions, and material characteristics.

[0029] The inflow zone is the initial area where fluid enters the target pipe at a certain pressure and flow rate; the outflow zone is the final area where fluid flows out of the target pipe at a certain pressure and flow rate.

[0030] Steady state refers to the state in which parameters such as pressure and flow rate of a fluid flowing in a pipe do not change over time and remain relatively stable. Under steady-state conditions, the measured pressure and flow rate data can serve as the basis for calculating parameters such as the pipe friction coefficient.

[0031] Pressure measurement refers to the fluid pressure value measured under steady-state conditions in the inflow and outflow regions of a target pipeline using a pressure measuring device (such as a pressure sensor); steady-state flow rate data refers to the fluid flow rate value measured under steady-state conditions in a target pipeline using a flow measuring device (such as a flow meter). Figure 2 The diagram shows a layout of a pressure measuring device and a flow measuring device. The pressure measuring device 201 is installed in the inflow and outflow areas of the target pipe 203, while the flow measuring device is installed at any location within the target pipe 203.

[0032] Pipeline parameters refer to various parameters that describe the physical characteristics of a target pipeline, including but not limited to the pipeline's length and diameter. These parameters directly affect the flow characteristics of fluids within the pipeline.

[0033] The friction coefficient is a factor that reflects the degree of energy loss caused by friction between the pipe walls and the fluid as it flows through a pipe. It depends on factors such as pipe roughness, fluid properties, and flow conditions. Specifically, it can be calculated using measured pressure differences between the inflow and outflow regions under steady-state conditions, steady-state flow rate data, and pipe geometric parameters. The coefficient is derived from the relationship between hydraulic gradient and flow rate, and is used to accurately characterize the impact of pipe friction loss on pressure wave propagation.

[0034] Discrete distance refers to the process of dividing a continuous pipeline into discrete numerical problems for numerical calculation and analysis. This involves dividing the pipeline along its length into several small segments, the length of which is the discrete distance. The discrete distance is determined based on the pipeline parameters.

[0035] Specifically, when the inflow and outflow regions of the target pipeline are in a steady state, pressure sensors and flow meters are used to measure pressure and flow data, respectively. Using these data, along with parameters such as pipeline length and diameter, the friction coefficient, reflecting pipeline friction loss, is derived and calculated through the relationship between hydraulic gradient and flow rate. Simultaneously, based on the pipeline parameters, the continuous pipeline is divided into several small segments along its length, and the length of each segment, i.e., the discrete distance, is determined, preparing for the subsequent transformation of the continuous pipeline problem into a discrete numerical problem for solution.

[0036] S102, based on the pipe parameters, friction coefficient and discrete distance of the target pipe, and with the measured pressure as the boundary condition, the transient flow characteristic propagation equation of the target pipe is constructed by the method of characteristics; the transient flow characteristic propagation equation is used to characterize the spatiotemporal variation characteristics of pressure and flow in the target pipe.

[0037] In this step, the method of characteristics is a numerical method for solving hyperbolic partial differential equations. It transforms the partial differential equations into a set of ordinary differential equations and solves them along specific characteristic lines, thereby obtaining the changes in pressure and flow rate of the fluid in the pipe over time and space.

[0038] The transient flow characteristic propagation equation is a mathematical equation constructed using the method of characteristics to describe the spatiotemporal variation characteristics of pressure and flow rate in a target pipeline. Specifically, it can be obtained by linearly combining and discretizing the mass conservation equation and momentum conservation equation using the method of characteristics, based on the pipeline parameters, friction coefficient, and discrete distance of the target pipeline. It is used to quantitatively express the pressure wave propagation speed, attenuation characteristics, and flow rate fluctuation law during transient flow.

[0039] Specifically, the pipe parameters of the target pipeline, the calculated friction coefficient, and the determined discrete distance are first defined, with the measured pressure used as the boundary condition. Using the method of characteristics, the mass conservation equation and momentum conservation equation describing fluid flow are linearly combined. Then, the parameters are discretized to transform the hyperbolic partial differential equation into a set of ordinary differential equations. These equations are solved along specific characteristic lines, thereby constructing a transient flow characteristic propagation equation that quantitatively expresses the spatiotemporal changes in pressure and flow rate in the target pipeline, reflecting pressure wave propagation and other phenomena during transient flow.

[0040] S103, based on the transient flow characteristic propagation equation, obtain transient flow characteristic information at each location in the target pipeline at each time, the transient flow characteristic information including at least one of pressure and flow rate.

[0041] In this step, transient flow characteristic information refers to the information related to transient flow exhibited at various locations in the target pipeline at various times, specifically including at least one of pressure and flow rate.

[0042] Specifically, based on the established transient flow characteristic propagation equation, this equation can quantitatively express the spatiotemporal variation characteristics of pressure and flow rate in a target pipeline. Given initial and boundary conditions, numerical calculation methods are used to solve the equation step-by-step along the time and space dimensions. During the solution process, calculations are performed at various locations within the target pipeline at specific times to obtain characteristic information related to the transient flow at each location at each time point. This information includes at least one of pressure and flow rate, thereby enabling dynamic analysis of the transient flow characteristics of the pipeline.

[0043] S104. Based on the transient flow feature information of each position in the target pipeline at each time, a transient flow feature field of the target pipeline is constructed; the transient flow feature field of the target pipeline is used for transient flow identification of the target pipeline.

[0044] In this step, the transient flow characteristic field is a comprehensive description and presentation of the transient flow (i.e., unsteady flow where the fluid flow state changes rapidly over time) characteristics within the target pipe. It integrates transient flow characteristic information (such as pressure and flow rate) from various locations within the target pipe at different times, and visually displays the spatiotemporal variation characteristics of pressure and / or flow rate of the transient flow within the target pipe in the form of a field.

[0045] Specifically, the process begins by collecting transient flow characteristic information, such as pressure and flow rate, at various locations within the target pipeline at different times. This scattered information is then systematically integrated according to location and time, combining the characteristic information from different locations at the same time to form the characteristic distribution within the pipeline at that time. Finally, the characteristic distributions from different times are concatenated. In this way, a comprehensive model reflecting the transient flow characteristics within the target pipeline—the transient flow characteristic field—is constructed. This field visually presents the changing characteristics of transient flow pressure and / or flow rate in time and space, facilitating subsequent transient flow identification.

[0046] This application integrates steady-state operating condition parameter calculation, characteristic line method discretization modeling, and global spatiotemporal feature field construction to form a reconstruction method from local measurement data to global transient flow characteristics. This method breaks through the data limitations of traditional single-point monitoring and achieves complete spatiotemporal analysis of pipeline transient flow processes.

[0047] As an example, for a long-distance pipeline, the pressure measurements and flow data of its inflow and outflow regions during steady-state operation are first obtained. For instance, the inflow pressure is 0.6 MPa, the outflow pressure is 0.4 MPa, and the steady-state flow rate is 2 m³ / s. Simultaneously, pipeline parameters are obtained, including a length of 10 km and a diameter of 1 m. Based on the above data, the hydraulic gradient of the pipeline is calculated to be 0.02 MPa / km. Substituting the hydraulic gradient, steady-state flow rate, pipeline length, and diameter into a preset friction coefficient calculation formula, the friction coefficient of the pipeline is obtained as 0.015.

[0048] Next, assuming the measured wave velocity in the pipeline is 1000 m / s and the pressure sampling time interval is 0.01 s, dividing the pipeline length by the product of the wave velocity and the sampling time interval yields a theoretical discrete number of 1000. Rounding down, the actual discrete number is determined to be 1000. Dividing the pipeline length by the total discrete number yields a discrete distance of 10 m.

[0049] Then, based on pipe parameters, friction coefficient, and discrete distance, transient flow mass conservation equations and transient flow momentum conservation equations are constructed. Characteristic parameters are introduced, and the transient flow mass conservation equations and transient flow momentum conservation equations are combined to obtain characteristic line equations. These characteristic line equations are then discretized to obtain the transient flow characteristic propagation equation. This transient flow characteristic propagation equation describes the spatiotemporal variation characteristics of pressure and flow rate in the pipe and can capture the nonlinear propagation process of transient flow.

[0050] Then, using the constructed transient flow characteristic propagation equation, with the pressure in the inflow and outflow regions as boundary conditions, pressure and flow rate data at various locations in the pipeline at various times are obtained through numerical solutions. For example, the pressure and flow rate values ​​at a location 5 km from the pipeline inlet 1 second after the transient occurs can be obtained. These pressure and flow rate data reflect the propagation law and energy change process of the transient flow within the pipeline.

[0051] Finally, the pressure and flow data acquired at various locations and times are organized and visualized to construct the transient flow characteristic field of the target pipeline, forming a three-dimensional surface map or contour map of pressure and flow variation with time and space.

[0052] like Figure 3 As shown, a schematic diagram of a transient flow characteristic field is presented. It displays the spatiotemporal analysis mesh of the target pipeline, with the horizontal axis representing the spatial location of the pipeline and the vertical axis representing time. The inflow pressure at pressure sensor monitoring point 1 and the outflow pressure at pressure sensor monitoring point 2 are used as boundary conditions, with a total length of... The target pipeline is divided into multiple equally spaced discrete segments, and time is also divided into multiple equally spaced steps, thus forming a two-dimensional grid structure that can be used to intuitively analyze the changes in transient flow characteristics within the pipeline over time and space.

[0053] In this embodiment, based on the measured pressure in the inflow and outflow regions of the target pipeline under steady-state conditions, the steady-state flow rate data of the target pipeline, and the pipeline parameters, the friction coefficient of the target pipeline is determined; and based on the pipeline parameters, the discrete distance of the target pipeline is determined. Because the data under steady-state conditions is relatively stable and reliable, it can provide accurate hydraulic fundamental data for subsequent analysis, accurately reflecting the basic characteristics of the pipeline. Then, the transient flow characteristic propagation equation constructed based on the pipeline parameters, friction coefficient, and discrete distance of the target pipeline can effectively characterize the spatiotemporal variation characteristics of pressure and flow rate in the pipeline, fully considering the spatiotemporal characteristics of transient flow. Finally, the transient flow characteristic field constructed based on this transient flow characteristic propagation equation can comprehensively characterize the pressure and / or flow rate distribution at various locations of the target pipeline at various times, no longer limited to the limited data of some monitoring points, overcoming the defect that data from only some monitoring points cannot fully present the changing law of transient flow process, thereby significantly improving the accuracy of transient flow analysis.

[0054] In some of the schemes described above in this application, the influence of the flow direction on the hydraulic gradient was not considered when determining the friction coefficient, which may cause the calculation results to deviate from the actual working conditions and affect the accuracy of the subsequent transient flow characteristic field.

[0055] In this regard, this application further proposes pipeline parameters including the length and diameter of the target pipeline; S101 may specifically include: The hydraulic gradient value of the target pipe is obtained by subtracting the measured pressure of the target pipe's outflow region from the measured pressure of the target pipe's inflow region when it is in steady state. Based on the hydraulic gradient value, steady-state flow data, and the length and diameter of the target pipe, the friction coefficient of the target pipe is determined using formula (1): (1); In formula (1), Used to characterize hydraulic gradient values, The symbol is used to represent the sign function, v is used to represent the steady-state flow rate data, L is used to represent the length of the target pipe, D is used to represent the diameter of the target pipe, and g is used to represent the gravitational acceleration. The friction coefficient is used to characterize the target pipeline.

[0056] In this embodiment, the hydraulic gradient value is the measured pressure in the inflow area of ​​the target pipe when it is in a steady state, minus the measured pressure in the outflow area of ​​the target pipe when it is in a steady state. It reflects the degree of pressure change along the flow path when the fluid flows in the target pipe.

[0057] The sign function is used to characterize the direction of steady-state flow data. Steady-state flow data can be positive or negative, representing the direction of fluid flow. The purpose of the sign function is to assign a corresponding sign value (positive or negative) based on the sign of the flow rate, ensuring that the influence of the flow direction on the hydraulic gradient is correctly reflected when calculating the friction coefficient.

[0058] When calculating the relationship between hydraulic gradient and friction coefficient, pipe length is an important factor. Generally speaking, the longer the pipe, the longer the fluid experiences frictional resistance during its flow within the pipe, potentially leading to greater energy loss and consequently affecting the hydraulic gradient.

[0059] Steady-state flow rate data refers to the volume of fluid passing through a cross-section of a pipe per unit time in a steady state. The flow rate directly affects the fluid's velocity and kinetic energy within the pipe, which in turn affects the friction with the pipe wall and the magnitude of the hydraulic gradient. A larger flow rate may result in stronger friction between the fluid and the pipe wall, and potentially a larger hydraulic gradient.

[0060] The diameter of a pipe has a significant impact on the flow state and frictional resistance of fluids. In pipes with larger diameters, the fluid flow has a larger relative space and relatively lower frictional resistance; while in pipes with smaller diameters, the fluid flow is more constrained and relatively higher.

[0061] Gravitational acceleration is used to unify and transform the dimensions of some physical quantities, ensuring the correct physical meaning of Formula 1.

[0062] This embodiment enables the accurate calculation of the friction coefficient of the target pipeline. This provides key parameters for the subsequent construction of the transient flow characteristic propagation equation, thereby improving the accuracy of the transient flow characteristic field construction. Furthermore, this method utilizes steady-state measurement data, avoiding complex measurements under transient flow conditions, simplifying the operation process, and improving efficiency.

[0063] In some of the schemes described above in this application, the coordination between wave velocity and sampling time interval needs to be considered when determining the discrete distance. If the discrete distance is not set properly, the calculation results after discretization of the characteristic line equation may deviate significantly from the actual physical process, affecting the accuracy of the transient flow characteristic field.

[0064] In this regard, this application further proposes pipeline parameters including the length of the target pipeline and the measured wave velocity; S101 may also include: The theoretical discrete number is obtained by dividing the ratio of the target pipe length to the measured wave velocity by the sampling time interval of the measured pressure. The theoretical discrete number is rounded down to obtain the actual discrete number; Divide the length of the target pipeline by the actual discrete number to obtain the discrete distance of the target pipeline.

[0065] In this embodiment, wave velocity measurement refers to the propagation speed of pressure waves within the target pipe. In a pipe fluid system, when transient flow phenomena occur (such as rapid changes in fluid state caused by the rapid closing or opening of valves), pressure waves and other fluctuations are generated. Wave velocity measurement is the measurement of the propagation speed of these pressure waves within the target pipe. It is influenced by various factors, including pipe material, fluid properties, and pipe constraints. For example, in a water-filled steel pipe, the propagation speed of the pressure wave is related to factors such as the elastic modulus of water, the elastic modulus of the steel pipe, and the wall thickness of the steel pipe.

[0066] The theoretical discrete number reflects the propagation of the target pipe according to the measured wave velocity at a given pressure sampling time interval; that is, the number of discrete segments into which the target pipe can theoretically be divided.

[0067] The actual discrete number is the value obtained by rounding down the theoretical discrete number. Rounding down means taking the largest integer not greater than the theoretical discrete number. This process is performed to obtain an integer number of discrete segments in actual numerical calculations and analysis, facilitating the discretization of the pipeline. Because in practical applications, the number of discrete segments must be an integer, rounding down ensures the reasonableness of the number of discrete segments and avoids problems such as fractional segments that do not conform to reality.

[0068] The discrete distance is the value obtained by dividing the length of the target pipe by the actual number of discrete segments. It represents the length of each discrete segment when the target pipe is discretized. By dividing the pipe into multiple discrete segments of equal length, the continuous pipe problem can be transformed into a discrete numerical computation problem, which facilitates the analysis and calculation of transient flow phenomena within the pipe.

[0069] The theoretical discrete number is calculated by the ratio of wave velocity to sampling time interval, ensuring that the time step and spatial step after discretization meet the stability condition. The rounding operation of the actual discrete number ensures that the discrete number is an integer, avoiding calculation errors caused by non-integer discrete numbers. The discrete distance is determined by the ratio of length to the actual discrete number, ensuring that the discretized grid points are evenly distributed within the pipe space.

[0070] Specifically, the product of the measured wave velocity and the sampling time interval is the spatial step size. The theoretical discrete number is the ratio of the pipe length to the spatial step size, which physically represents the number of discrete segments into which the pipe is divided, matching the wave velocity propagation characteristics. Rounding eliminates the decimal part of the theoretical discrete number, ensuring the number of discrete segments is an integer and avoiding non-uniform discretization. The discrete distance is calculated by the ratio of the target pipe length to the integer number of discrete segments, ensuring that each discrete segment has an equal length and guaranteeing synchronization between the time and spatial steps after discretization of the characteristic line equation.

[0071] As an example, the theoretical discrete number is first obtained by dividing the ratio of the target pipe length to the measured wave velocity by the sampling time interval of the measured pressure. For instance, assuming the target pipe length is 1000 meters, the measured wave velocity is 1000 m / s, and the sampling time interval of the measured pressure is 0.1 seconds, the theoretical discrete number is 10. Next, the theoretical discrete number is rounded down to obtain the actual discrete number. In this example, the actual discrete number is 10. Finally, the target pipe length is divided by the actual discrete number to obtain the discrete distance of the target pipe. In this example, the discrete distance of the target pipe is 100 meters. This method ensures that the discretized characteristic line equation strictly satisfies the wave velocity propagation law in both time and space dimensions, avoiding numerical oscillations or divergence problems caused by mismatched discrete parameters.

[0072] This embodiment enables the accurate determination of the discrete distance of the target pipeline, providing a foundation for constructing the characteristic propagation equation of transient flow. This allows for a more precise description of the propagation characteristics of transient flow within the pipeline, improving the accuracy of transient flow analysis. Furthermore, by appropriately selecting the discrete distance, computational complexity can be reduced while maintaining computational accuracy, thereby improving the efficiency of constructing the transient flow characteristic field.

[0073] In some of the schemes described above in this application, determining the friction coefficient of the target pipeline requires measuring pressure and flow data under steady-state conditions. However, in actual operation, the pipeline may be in an unsteady state, and the collected data may fluctuate dynamically. If it is directly used to calculate the friction coefficient, it will lead to deviation in the results, which will affect the accuracy of the subsequent construction of the transient flow characteristic field.

[0074] In this regard, prior to S101, this application further proposes that the transient flow identification method may also include: Based on a preset frequency, transient flow characteristic information of the target pipeline is collected; The first transient flow characteristic information of the target pipeline at the first moment is subtracted from the second transient flow characteristic information of the target pipeline at the second moment to obtain the characteristic information difference of the target pipeline; the second moment is N acquisition moments before the first moment and N is a positive integer. If the difference in feature information is less than a preset steady-state threshold, the target pipeline is determined to be in a steady state at the first moment.

[0075] In this embodiment, the preset frequency refers to the frequency value set in advance for collecting transient flow characteristic information of the target pipeline, which determines the time interval for collecting transient flow characteristic information.

[0076] The first moment is a specific point in time used to acquire transient flow characteristic information of the target pipeline. The transient flow characteristic information acquired at the first moment is called the first transient flow characteristic information. The second moment is another specific point in time used to acquire transient flow characteristic information of the target pipeline. The transient flow characteristic information acquired at the second moment is called the second transient flow characteristic information.

[0077] The second time point precedes the first time point, with an interval of N data acquisition times between them. For example, assuming the acquisition times are t1, t2, t3, t4, ..., if the first time point is t4 and N=2, then the second time point is t2. The setting of the first and second time points is to compare the transient flow characteristics of the target pipeline at different time points, thereby determining whether the pipeline is in a steady state.

[0078] The feature information difference is the result obtained by subtracting the second transient flow feature information of the target pipeline at the second time from the first transient flow feature information of the target pipeline at the first time. If the transient flow feature information contains multiple parameters (such as pressure and flow rate), then the feature information difference is a set of differences between the multiple parameters.

[0079] The preset frequency setting needs to be combined with the dynamic response time of the transient flow to ensure that the data acquisition interval can capture pressure fluctuations. The interval N between the first and second acquisition moments is adjusted according to the actual operating conditions, and the value of N must meet the requirements for data stability judgment. The preset steady-state threshold is set based on historical statistical values ​​or empirical values ​​of pipeline operating parameters; for example, a pressure fluctuation amplitude of less than 5% can be considered steady state.

[0080] Specifically, pressure or flow data of the target pipeline is periodically collected at a preset frequency to ensure data continuity over time. By comparing the difference in characteristic information between the current moment and historical moments, the decay process of transient changes can be effectively identified. When the difference in characteristic information is lower than a preset steady-state threshold, it indicates that the fluid motion inside the pipeline tends to be in equilibrium, and the collected pressure and flow data at this time have steady-state characteristics. Therefore, the friction coefficient calculated based on the steady-state data can accurately reflect the friction characteristics of the pipeline, providing reliable input parameters for the subsequent construction of the transient flow characteristic propagation equation.

[0081] As an example, transient flow characteristic information of the target pipeline is first collected based on a preset frequency. For instance, a high-frequency pressure sensor can be used to collect pressure data inside the pipeline at a sampling frequency of 100Hz.

[0082] Next, subtract the second transient flow characteristic information of the target pipeline at the second time point from the first transient flow characteristic information of the target pipeline at the first time point to obtain the characteristic information difference of the target pipeline. The second time point is defined as N data acquisition times prior to the first time point and N is a positive integer. Specifically, N=100 can be chosen, meaning two pressure data points separated by 1 second are compared.

[0083] Finally, if the difference in feature information is less than a preset steady-state threshold, the target pipeline is determined to be in a steady state at the first moment. For example, the preset steady-state threshold can be set to 1 kPa. When the pressure difference is less than 1 kPa, the target pipeline is determined to be in a steady state.

[0084] This embodiment enables accurate determination of whether a pipeline is in a steady state. This provides reliable steady-state data for subsequent friction coefficient calculations, avoiding inaccurate results caused by using unsteady-state data. Furthermore, by setting appropriate sampling frequencies and comparison time intervals, the influence of short-term fluctuations can be effectively filtered out, improving the accuracy and stability of steady-state determination.

[0085] In some of the above-mentioned schemes in this application, when constructing the characteristic propagation equation of transient flow using the method of characteristics, the traditional method does not fully consider the influence of pipe wave velocity and cross-sectional area on the characteristic parameters, which makes the equation unable to accurately characterize the dynamic propagation characteristics of transient flow in the spatiotemporal dimension, thereby affecting the accuracy of subsequent construction of transient flow characteristic field.

[0086] In this regard, this application further proposes that S102 may specifically include: Based on the pipe parameters and friction coefficient of the target pipe, the transient flow mass conservation equation and transient flow flux conservation equation of the target pipe are constructed. Based on the target wave velocity and cross-sectional area of ​​the target pipeline, the characteristic parameters of the target pipeline are determined; the target wave velocity is either the measured wave velocity obtained by measuring the target pipeline, or the corrected wave velocity obtained by correcting the measured wave velocity based on the discrete distance of the target pipeline. Based on the characteristic parameters of the target pipeline, the transient flow mass conservation equation and the transient flow momentum conservation equation are linearly combined to obtain the characteristic line equation. Based on the discrete distance of the target pipeline, the characteristic line equation is discretized to obtain the transient flow characteristic propagation equation of the target pipeline.

[0087] In this embodiment, the transient flow mass conservation equation is constructed based on the pipe parameters of the target pipe using the following formula (2): (2); In formula (2), g is the acceleration due to gravity, A is the cross-sectional area of ​​the pipe, a is the target wave velocity of the pipe, H is the piezometric head of the target pipe, t is the time coordinate, Q is the flow rate, and x is the position coordinate. This represents the creep deformation of the target pipeline.

[0088] The transient flow conservation equation is constructed based on the pipe parameters and friction coefficient of the target pipe using the following formula (3): (3); In formula (3), g is the acceleration due to gravity, A is the cross-sectional area of ​​the pipe, H is the piezometric head of the target pipe, t is the time coordinate, Q is the flow rate, and x is the position coordinate. Let be the creep deformation of the target pipe, D be the pipe inner diameter, v be the kinematic viscosity, and W be the weighting function for unsteady friction. This refers to the time required for convolution. For fluid density, This is the coefficient of friction.

[0089] The characteristic parameters are determined based on the target wave velocity and cross-sectional area of ​​the target pipe, using the following formula (4): (4); In formula (4), is the characteristic parameter, g is the gravitational acceleration, A is the cross-sectional area of ​​the pipe, and a is the target wave velocity of the target pipe.

[0090] Based on the characteristic parameters of the target pipeline, the characteristic line equation obtained by linearly combining the transient flow mass conservation equation and the transient flow momentum conservation equation is shown in the following formula (5): (5); In formula (5), H is the pressure head of the target pipeline, t is the time coordinate, Q is the flow rate, g is the gravitational acceleration, A is the cross-sectional area of ​​the pipeline, a is the wave velocity of the pipeline, and R is the energy loss term.

[0091] Finally, the characteristic line equations are discretized to obtain the transient flow characteristic propagation equations, including the first characteristic line equation and the second characteristic line equation, which are shown in the following formulas (6) and (7), respectively: (6); (7); In formulas (6) and (7), , , as well as These are the equation coefficients of the first and second characteristic line equations, respectively, which can be calculated using the flow rate and pressure at previous time points. Used to characterize the flow rate at location x at time t. Used to characterize the pressure at position x at time t.

[0092] The transient flow mass conservation equation and transient flow momentum conservation equation are established using the principle of fluid continuity and Newton's second law, respectively, and together describe the spatiotemporal relationship between pressure and flow rate. The target wave velocity is either the measured wave velocity or a wave velocity corrected based on discrete distance. The corrected wave velocity is calculated by dividing the discrete distance by the sampling time interval. The characteristic parameter is obtained by dividing the product of the cross-sectional area and gravitational acceleration by the corrected wave velocity; this parameter is used to adjust the linear combination weights of the conservation equations. The characteristic line equation is formed by superimposing the mass conservation equation and the momentum conservation equation according to the characteristic parameter ratio. Its physical meaning is the dynamic equilibrium relationship between the pressure wave and the flow wave propagating along the characteristic line direction. Discretization is performed using the finite difference method, dividing the continuous space into multiple computational nodes according to discrete distances, with the time step and spatial step satisfying stability conditions.

[0093] Specifically, in constructing the transient flow characteristic propagation equation, the partial differential relationships between pressure, flow rate, time, and space are first established using the transient flow mass conservation equation and the transient flow flux conservation equation. Target wave velocity and cross-sectional area are then introduced to calculate characteristic parameters. These parameters transform the transient flow mass conservation equation and the transient flow flux conservation equation into wave equations propagating along characteristic lines, eliminating cross-derivative terms in the equations. Subsequently, the characteristic line equation is approximated by difference at spatial nodes divided by discrete distances, thus obtaining the transient flow characteristic propagation equation for the target pipeline. The transient flow characteristic propagation equation obtained through this process can accurately describe the propagation velocity and attenuation characteristics of pressure waves in the pipeline, providing a high-precision numerical calculation basis for constructing the transient flow characteristic field.

[0094] This embodiment achieves an accurate description and propagation simulation of transient flow characteristics in a target pipeline. By constructing transient flow mass and momentum conservation equations and combining them with the method of characteristics, a transient flow characteristic propagation equation that accurately characterizes the spatiotemporal variations of pressure and flow rate in the pipeline is obtained. This method avoids the limitations of relying solely on data from a small number of monitoring points, improving the accuracy and comprehensiveness of transient flow analysis.

[0095] In some of the solutions described above in this application, a method for determining characteristic parameters by measuring wave velocity was proposed. However, when there are instrument errors or environmental interference in the wave velocity measurement, directly using the wave velocity measurement may cause the characteristic parameters to deviate from the actual physical properties, thereby affecting the accuracy of the transient flow characteristic propagation equation.

[0096] In response, this application further proposes determining the characteristic parameters of the target pipeline based on the target wave velocity and the cross-sectional area of ​​the target pipeline. Specifically, these parameters may include: The corrected wave velocity is obtained by dividing the discrete distance of the target pipe by the sampling time interval of the pressure measurement. The product of the cross-sectional area of ​​the target pipe and the gravitational acceleration is divided by the corrected wave velocity to obtain the target calculation result; Based on the target calculation results, the characteristic parameters of the target pipeline are determined.

[0097] In this embodiment, the discrete distance is obtained by dividing the ratio of the pipe length to the measured wave velocity by the sampling time interval and rounding down to obtain the total discrete distance. This total discrete distance is then calculated by dividing the pipe length by the total discrete distance. The corrected wave velocity is calculated using the ratio of the discrete distance to the sampling time interval, eliminating random errors in the measured wave velocity. The cross-sectional area is calculated based on the pipe diameter determined geometrically, and the gravitational acceleration is a known physical constant. The target calculation result is obtained by multiplying the cross-sectional area by the gravitational acceleration and dividing by the corrected wave velocity, forming a dimensionless parameter combination to ensure that the characteristic parameters match the actual dynamic characteristics of the pipe.

[0098] Specifically, in constructing the characteristic propagation equations for transient flow, the corrected wave velocity is recalculated by dividing the discrete distance by the sampling time interval, avoiding the cumulative error that might be introduced by directly using the measured wave velocity. The product of the cross-sectional area and gravitational acceleration reflects the fluid's inertial effect, and the corrected wave velocity characterizes the correction value of the pressure wave propagation velocity. The ratio of the two couples the fluid motion characteristics with the pipe's geometric parameters. This ratio determines the characteristic parameters, ensuring that the linear combination of the transient flow mass conservation equation and momentum conservation equation maintains mathematical consistency with the physical conservation laws during the discretization process.

[0099] This embodiment enables the accurate determination of the characteristic parameters of the target pipeline. This improves the accuracy of constructing the transient flow characteristic propagation equation, thereby enhancing the accuracy of constructing the transient flow characteristic field. Specifically, by introducing a corrected wave velocity and considering the influence of discrete distance on wave velocity, the calculation of characteristic parameters becomes more closely aligned with actual conditions. This method avoids the errors that may arise from directly using measured wave velocity, thus providing more reliable basic data for subsequent transient flow analysis.

[0100] Based on the transient flow identification method provided in this application, correspondingly, this application also provides specific embodiments of a transient flow identification device.

[0101] like Figure 4 As shown, the transient flow identification device 400 provided in this application embodiment includes a parameter determination module 410, an equation construction module 420, an information acquisition module 430, and a feature field construction module 440.

[0102] The parameter determination module 410 is used to determine the friction coefficient of the target pipeline based on the measured pressure when the inflow and outflow regions of the target pipeline are in steady state, the steady-state flow data of the target pipeline, and the pipeline parameters; and to determine the discrete distance of the target pipeline based on the pipeline parameters. The equation construction module 420 is used to construct the transient flow characteristic propagation equation of the target pipeline based on the pipeline parameters, friction coefficient, and discrete distance of the target pipeline, with the measured pressure as the boundary condition, using the method of characteristics; the transient flow characteristic propagation equation is used to characterize the spatiotemporal variation characteristics of pressure and flow rate in the target pipeline; The information acquisition module 430 is used to acquire transient flow characteristic information at each location in the target pipeline at each time based on the transient flow characteristic propagation equation. The transient flow characteristic information includes at least one of pressure and flow rate. The feature field construction module 440 is used to construct the transient flow feature field of the target pipeline based on the transient flow feature information of each position in the target pipeline at each time; the transient flow feature field of the target pipeline is used for transient flow identification of the target pipeline.

[0103] The transient flow identification device provided in this application determines the friction coefficient of the target pipe based on the measured pressure in the inflow and outflow regions of the target pipe under steady-state conditions, the steady-state flow rate data of the target pipe, and the pipe parameters; and determines the discrete distance of the target pipe based on the pipe parameters. Because the data is relatively stable and reliable under steady-state conditions, it can provide accurate hydraulic fundamental data for subsequent analysis, accurately reflecting the basic characteristics of the pipe. Then, the transient flow characteristic propagation equation constructed based on the pipe parameters, friction coefficient, and discrete distance of the target pipe can effectively characterize the spatiotemporal variation characteristics of pressure and flow rate in the pipe, fully considering the spatiotemporal characteristics of transient flow. Finally, the transient flow characteristic field constructed based on the transient flow characteristic propagation equation can comprehensively characterize the pressure and / or flow rate distribution at various locations of the target pipe at various times, no longer limited to the limited data of some monitoring points, overcoming the defect that data from only some monitoring points cannot fully present the changing law of transient flow process, thereby significantly improving the accuracy of transient flow analysis.

[0104] Furthermore, this application also proposes that the pipeline parameters include the length and diameter of the target pipeline; Parameter determination module 410 is specifically used for: The hydraulic gradient value of the target pipe is obtained by subtracting the measured pressure of the target pipe's outflow region from the measured pressure of the target pipe's inflow region when it is in steady state. Based on the hydraulic gradient value, steady-state flow data, and the length and diameter of the target pipe, the friction coefficient of the target pipe is determined using the first formula: ; in, Used to characterize hydraulic gradient values, The symbol is used to represent the sign function, v is used to represent the steady-state flow rate data, L is used to represent the length of the target pipe, D is used to represent the diameter of the target pipe, and g is used to represent the gravitational acceleration. The friction coefficient is used to characterize the target pipeline.

[0105] Furthermore, this application also proposes that the pipeline parameters include the length of the target pipeline and the measured wave velocity; The parameter determination module 410 is also used for: The theoretical discrete number is obtained by dividing the ratio of the target pipe length to the measured wave velocity by the sampling time interval of the measured pressure. The theoretical discrete number is rounded down to obtain the actual discrete number; Divide the length of the target pipeline by the actual discrete number to obtain the discrete distance of the target pipeline.

[0106] Furthermore, this application also proposes that, before determining the friction coefficient of the target pipeline based on the measured pressure when the inflow and outflow regions of the target pipeline are in steady state, the steady-state flow data of the target pipeline, and pipeline parameters, the transient flow identification device 400 further includes: The information acquisition module is used to collect transient flow characteristic information of the target pipeline based on a preset frequency; The information analysis module is used to subtract the second transient flow characteristic information of the target pipeline at the second time from the first transient flow characteristic information of the target pipeline at the first time, so as to obtain the characteristic information difference of the target pipeline; the second time is before the first time and the interval between the second time and the first time is N acquisition time, where N is a positive integer; The steady-state identification module is used to determine that the target pipeline is in a steady state at the first moment when the difference in feature information is less than a preset steady-state threshold.

[0107] Furthermore, this application also proposes an equation construction module 420, which specifically includes the following units: The equation building unit is used to construct the transient flow mass conservation equation and transient flow flux conservation equation for the target pipeline based on the pipeline parameters and friction coefficient of the target pipeline. The parameter determination unit is used to determine the characteristic parameters of the target pipe based on the target wave velocity and the cross-sectional area of ​​the target pipe; the target wave velocity is the measured wave velocity obtained by measuring the target pipe, or the corrected wave velocity obtained by correcting the measured wave velocity based on the discrete distance of the target pipe. The equation combination unit is used to linearly combine the transient flow mass conservation equation and the transient flow momentum conservation equation based on the characteristic parameters of the target pipeline to obtain the characteristic line equation. The equation discretization unit is used to discretize the characteristic line equation based on the discrete distance of the target pipeline, so as to obtain the transient flow characteristic propagation equation of the target pipeline.

[0108] Furthermore, this application also proposes a parameter determination unit, specifically used for: The corrected wave velocity is obtained by dividing the discrete distance of the target pipe by the sampling time interval of the pressure measurement. The product of the cross-sectional area of ​​the target pipe and the gravitational acceleration is divided by the corrected wave velocity to obtain the target calculation result; Based on the target calculation results, the characteristic parameters of the target pipeline are determined.

[0109] Based on the transient flow identification method provided in this application, correspondingly, this application also provides specific embodiments of a transient flow identification device.

[0110] Figure 5 A schematic diagram of the hardware structure of the transient flow identification device provided in an embodiment of this application is shown.

[0111] The transient flow identification device may include a processor 501 and a memory 502 storing computer program instructions.

[0112] Specifically, the processor 501 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0113] Memory 502 may include mass storage for data or instructions. For example, and not limitingly, memory 502 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 502 may include removable or non-removable (or fixed) media. Where appropriate, memory 502 may be internal to an integrated gateway disaster recovery device. In a particular embodiment, memory 502 is non-volatile solid-state memory.

[0114] The processor 501 implements any of the transient flow identification methods in the above embodiments by reading and executing computer program instructions stored in the memory 502.

[0115] In one example, the transient flow identification device may also include a communication interface 503 and a bus 510. Wherein, as Figure 5As shown, the processor 501, memory 502, and communication interface 503 are connected through bus 510 and complete communication with each other.

[0116] The communication interface 503 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0117] Bus 510 includes hardware, software, or both, that couples components of a transient stream identification device together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 510 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, any suitable bus or interconnect is contemplated herein.

[0118] Furthermore, in conjunction with the feature matching result verification method in the above embodiments, this application embodiment can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the transient flow identification methods in the above embodiments.

[0119] In addition, in conjunction with the feature matching result verification method in the above embodiments, this application embodiment can provide a computer program product for implementation. When the instructions in the computer program product are executed by the processor of the electronic device, the electronic device executes the transient flow identification method provided by any aspect of the above embodiments of this application.

[0120] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0121] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0122] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0123] The aspects of this disclosure have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowchart illustrations, and combinations of blocks in the block diagrams and / or flowchart illustrations, can also be implemented by special-purpose hardware performing the specified functions or actions, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0124] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A transient flow identification method, characterized in that, The method includes: Based on the measured pressure in the inflow and outflow regions of the target pipeline when they are in steady state, the steady-state flow data of the target pipeline, and the pipeline parameters, the friction coefficient of the target pipeline is determined; based on the pipeline parameters of the target pipeline, the discrete distance of the target pipeline is determined. Based on the pipe parameters, friction coefficient, and discrete distance of the target pipe, and with the measured pressure as the boundary condition, the transient flow characteristic propagation equation of the target pipe is constructed using the method of characteristics; the transient flow characteristic propagation equation is used to characterize the spatiotemporal variation characteristics of pressure and flow rate in the target pipe. Based on the transient flow characteristic propagation equation, transient flow characteristic information at each location in the target pipeline at each time is obtained, wherein the transient flow characteristic information includes at least one of pressure and flow rate; Based on the transient flow characteristic information of each position in the target pipeline at each time, a transient flow characteristic field of the target pipeline is constructed; the transient flow characteristic field of the target pipeline is used for transient flow identification of the target pipeline.

2. The method according to claim 1, characterized in that, The pipeline parameters include the length and diameter of the target pipeline; The determination of the friction coefficient of the target pipeline based on the measured pressure in the steady-state inflow and outflow regions of the target pipeline, the steady-state flow data of the target pipeline, and pipeline parameters includes: The hydraulic gradient value of the target pipe is obtained by subtracting the measured pressure of the target pipe's outflow region from the measured pressure of the target pipe's inflow region when it is in a steady state. Based on the hydraulic gradient value, the steady-state flow data, and the length and diameter of the target pipe, the friction coefficient of the target pipe is determined by a first formula, which is: ； in, Used to characterize the hydraulic gradient value The sign function is used to represent the steady-state flow rate data, L is used to represent the length of the target pipe, D is used to represent the diameter of the target pipe, and g is used to represent the gravitational acceleration. The coefficient of friction used to characterize the target pipe.

3. The method according to claim 1, characterized in that, The pipeline parameters include the length of the target pipeline and the measured wave velocity; Determining the discrete distance of the target pipeline based on its pipeline parameters includes: The theoretical discrete number is obtained by dividing the ratio of the length of the target pipe to the measured wave velocity by the sampling time interval of the measured pressure. The theoretical discrete number is rounded down to obtain the actual discrete number; Divide the length of the target pipeline by the actual discrete number to obtain the discrete distance of the target pipeline.

4. The method according to any one of claims 1-3, characterized in that, Before determining the friction coefficient of the target pipeline based on the measured pressure in the inflow and outflow regions of the target pipeline when they are in a steady state, the steady-state flow data of the target pipeline, and pipeline parameters, the method further includes: Based on a preset frequency, transient flow characteristic information of the target pipeline is collected; The first transient flow feature information of the target pipeline at the first time point is subtracted from the second transient flow feature information of the target pipeline at the second time point to obtain the feature information difference of the target pipeline; the second time point is before the first time point and there is an interval of N acquisition time points between the second time point and the first time point, where N is a positive integer; If the difference in the feature information is less than a preset steady-state threshold, the target pipeline is determined to be in a steady state at the first moment.

5. The method according to any one of claims 1-3, characterized in that, The transient flow characteristic propagation equation of the target pipeline is constructed using the method of characteristics, based on the pipeline parameters, friction coefficient, and discrete distance of the target pipeline, with the measured pressure as the boundary condition. This includes: Based on the pipe parameters and friction coefficient of the target pipe, the transient flow mass conservation equation and transient flow flux conservation equation of the target pipe are constructed. Based on the target wave velocity and the cross-sectional area of ​​the target pipeline, the characteristic parameters of the target pipeline are determined; the target wave velocity is either a measured wave velocity obtained by measuring the target pipeline, or a corrected wave velocity obtained by correcting the measured wave velocity based on the discrete distance of the target pipeline. Based on the characteristic parameters of the target pipeline, the transient flow mass conservation equation and the transient flow momentum conservation equation are linearly combined to obtain the characteristic line equation. Based on the discrete distance of the target pipeline, the characteristic line equation is discretized to obtain the transient flow characteristic propagation equation of the target pipeline.

6. The method according to claim 5, characterized in that, The determination of characteristic parameters of the target pipeline based on the target wave velocity and the cross-sectional area of ​​the target pipeline includes: The corrected wave velocity is obtained by dividing the discrete distance of the target pipeline by the sampling time interval of the measured pressure. The target calculation result is obtained by dividing the product of the cross-sectional area of ​​the target pipe and the gravitational acceleration by the corrected wave velocity. Based on the target calculation results, the characteristic parameters of the target pipeline are determined.

7. A transient flow identification device, characterized in that, The device includes: The parameter determination module is used to determine the friction coefficient of the target pipeline based on the measured pressure in the inflow and outflow regions of the target pipeline when they are in a steady state, the steady-state flow data of the target pipeline, and the pipeline parameters; and to determine the discrete distance of the target pipeline based on the pipeline parameters. The equation construction module is used to construct the transient flow characteristic propagation equation of the target pipeline based on the pipeline parameters, friction coefficient, and discrete distance of the target pipeline, with the measured pressure as the boundary condition, using the method of characteristics; the transient flow characteristic propagation equation is used to characterize the spatiotemporal variation characteristics of pressure and flow rate in the target pipeline; The information acquisition module is used to acquire transient flow characteristic information at each location in the target pipeline at each time based on the transient flow characteristic propagation equation, wherein the transient flow characteristic information includes at least one of pressure and flow rate; The feature field construction module is used to construct the transient flow feature field of the target pipeline based on the transient flow feature information of each position in the target pipeline at each time; the transient flow feature field of the target pipeline is used for transient flow identification of the target pipeline.

8. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the transient flow identification method according to any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the transient flow identification method according to any one of claims 1 to 6.

10. A computer program product, the computer program product comprising a computer program, characterized in that, The computer program is read and executed by the processor of the computer device, causing the computer device to perform the transient flow identification method according to any one of claims 1 to 6.

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