Pipeline flow measuring method and device for non-full-flow pipeline

Abstract

The invention discloses a pipeline flow measurement method and device for a non-full-flow pipeline, and relates to the technical field of pipeline flow measurement, measurement is carried out through a pipeline flow measurement system, and the pipeline flow measurement system comprises a sonar probe which is arranged in the pipeline and floats on the water surface of the pipeline and a Doppler flow meter which is arranged in a water passing area in the pipeline. The method comprises the steps that a target echo signal, detected by a sonar probe, of a water passing area in a pipeline is acquired, and section contour data and section area of the water passing area are determined according to the target echo signal; performing grid division on the water passing area according to the section contour data to obtain a preset number of grid units, and calculating flow velocity distribution of each grid unit through frequency shift detected by a Doppler flow velocity meter; on each grid unit, the corresponding flow velocity value is multiplied by the area of the grid unit according to the flow velocity distribution, and then summation is carried out to obtain the pipeline flow. The problem that in the prior art, the accuracy is low when the pipeline flow of the non-full-flow pipeline is measured is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline flow measurement, and particularly relates to a method and device for measuring the pipeline flow of a non-full-flow pipeline. Background Art

[0002] With the development of modern technology, pipe networks are becoming increasingly important in people's daily lives. Among them, the measurement of pipeline flow is an important link in industries, agriculture, water conservancy and other fields, and its accuracy directly affects production efficiency, resource utilization rate and cost control. The existing pipeline flow measurement methods are as follows: Ultrasonic flowmeter method: Its principle is to calculate the flow velocity by using the time difference (time difference method) or frequency difference (Doppler method) of ultrasonic waves propagating in the fluid, so as to obtain the flow rate; Electromagnetic flowmeter method: The principle is based on Faraday's law of electromagnetic induction. When a conductive fluid flows through an externally applied magnetic field, an induced electromotive force proportional to the flow velocity will be generated, and the electromotive force is measured by electrodes and then converted into a flow rate; Vortex street flowmeter method: The principle of the vortex street flowmeter is a flow measurement instrument based on the Karman vortex street principle, which is widely used to measure the volume flow rate or mass flow rate of liquids, gases and steam; Radar flow velocity method: It is a method for measuring the flow velocity of the fluid surface based on radar technology, mainly used to measure the flow velocity of open water bodies such as rivers, open channels, and canals; Video imaging method: It is a flow measurement method based on computer vision technology. By shooting the dynamic image of the water surface with a camera device, combined with image processing and fluid mechanics principles, the motion characteristics of the fluid are analyzed, so as to calculate the flow velocity and flow rate.

[0003] However, whether it is the ultrasonic flowmeter method, the electromagnetic flowmeter method, the vortex street flowmeter method, the radar flow velocity method or the video imaging method, under non-full pipe conditions, since the fluid in the pipeline is only partially filled, it will lead to large measurement errors and ultimately result in low measurement accuracy. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method and device for measuring the pipeline flow of a non-full-flow pipeline, aiming to solve the problem of low accuracy in measuring the pipeline flow of a non-full-flow pipeline in the prior art.

[0005] On the one hand, the present invention provides a method for measuring the pipeline flow of a non-full-flow pipeline, which measures the pipeline flow of a non-full-flow pipeline through a pipeline flow measurement system. The pipeline flow measurement system includes a sonar probe floating on the water surface of the pipeline in the pipeline and a Doppler flow velocity meter placed in the water passing area of the pipeline. The method includes: Obtain the echo signal detected by the sonar probe, determine the target echo signal in the water passing area of the pipeline, and determine the cross-sectional profile data and cross-sectional area of the water passing area according to the target echo signal; Grid division is performed on the water passage area according to the cross-section profile data to obtain a preset number of grid cells, and the flow velocity distribution of each grid cell is calculated by the frequency shift detected by the Doppler flow velocity meter; On each grid cell, the corresponding flow velocity value is multiplied by the area of the grid cell according to the flow velocity distribution and then summed to obtain the pipeline flow rate.

[0006] Further, in the above method for measuring the pipeline flow rate of a non-full-flow pipeline, the steps of obtaining the echo signal detected by the sonar probe, determining the target echo signal in the water passage area of the pipeline, and determining the cross-section profile data and cross-section area of the water passage area according to the target echo signal include: The target echo signal is extracted from the echo signals according to the echo intensity of the echo signals; The time difference between the target echo signals at different positions and the transmitted signal and the propagation speed of the target echo signals are obtained to obtain the cross-section profile data composed of the two-dimensional coordinates of discrete points inside the pipeline cross-section; The cross-section area of the corresponding water passage area is calculated by using the trapezoidal method for definite integral according to the cross-section profile data.

[0007] Further, in the above method for measuring the pipeline flow rate of a non-full-flow pipeline, the calculation formula for the cross-section area of the water passage area is: ; Among them, a, b is the integration interval, f ( x i ) is the function value corresponding to the integration interval, which can be obtained from the two-dimensional coordinates of the discrete points, x i is the step size, and the integration interval [a, b] is evenly divided into h sub-intervals, N =( h ) / b - a ), N , N is the number of divided intervals.

[0008] Further, in the above method for measuring the pipeline flow rate of a non-full-flow pipeline, the steps of performing grid division on the water passage area according to the cross-section profile data to obtain a preset number of grid cells and calculating the flow velocity distribution of each grid cell by the frequency shift detected by the Doppler flow velocity meter include: Define the grid range of the water passage area according to the maximum and minimum values of the two-dimensional coordinates of the discrete points; Divide the cross-section of the water passage area into two-dimensional grid cells, and determine the coordinates of each grid cell according to the grid resolution; Determine the central velocity of the graphic center of the water passing area based on the frequency shift detected by the Doppler current meter, and determine the distance from the graphic center to each grid cell according to the coordinates of each grid cell and the coordinates of the graphic center; Calculate the flow velocity distribution of each grid cell by interpolation through the inverse distance weighting method with the distance from the graphic center to each grid cell weighted according to the central velocity.

[0009] Furthermore, for the above method for measuring the pipeline flow rate of an unpressurized pipeline, wherein the calculation formula for the central velocity is: ; Wherein, is the frequency shift at the graphic center of the water passing area, f t is the transmission frequency of the Doppler current meter, c is the propagation velocity of sound waves in the fluid, θ is the angle between the sound wave propagation direction and the particle movement direction in the fluid.

[0010] Furthermore, for the above method for measuring the pipeline flow rate of an unpressurized pipeline, wherein the calculation formula for the inverse distance weighting method is: ; Wherein, is the reciprocal of the Euclidean distance between the i th grid cell and the graphic center, n is the number of grid cells, is the central velocity of the corresponding graphic center, is the flow velocity value of the target grid cell to be calculated.

[0011] Furthermore, for the above method for measuring the pipeline flow rate of an unpressurized pipeline, wherein the method further includes: Convert the signals of the sonar and the Doppler current meter into corresponding numerical data through analog-to-digital conversion; Among them, the continuous signals of the sonar and the Doppler current meter are sampled at time intervals to generate discrete signal values, and then the sampled signal values are mapped into finite discrete level values to be converted into corresponding numerical data.

[0012] Another object of the present invention is to provide a device for measuring the pipeline flow rate of an unpressurized pipeline. The pipeline flow rate is measured by a pipeline flow measurement system. The pipeline flow measurement system includes a sonar probe floating on the water surface in the pipeline and a Doppler current meter placed in the water passing area in the pipeline. The device includes: An acquisition module, configured to acquire the echo signals detected by a sonar probe, determine the target echo signals of the water passage area in the pipeline, and determine the cross-sectional profile data and cross-sectional area of the water passage area according to the target echo signals; A division module, configured to perform grid division on the water passage area according to the cross-sectional profile data to obtain a preset number of grid units, and calculate the flow velocity distribution of each grid unit through the frequency shift detected by a Doppler flowmeter; A measurement module, configured to sum the corresponding flow velocity values multiplied by the area of each grid unit according to the flow velocity distribution on each grid unit to obtain the pipeline flow rate.

[0013] Another object of the present invention is to provide a readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps of the above method are implemented.

[0014] Another object of the present invention is to provide an electronic device, including a memory, a processor, and a computer program stored on the memory and running on the processor, and when the processor executes the program, the steps of the above method are implemented.

[0015] In the present invention, a sonar probe is arranged on the water surface of the pipeline in the pipeline, and a Doppler flowmeter is arranged in the water passage area of the pipeline. The target echo signals of the water passage area in the pipeline are determined through the echo signals detected by the sonar probe, and the cross-sectional profile data and cross-sectional area of the water passage area are determined according to the target echo signals; the water passage area is divided into a preset number of grid units according to the cross-sectional profile data, and the flow velocity distribution of each grid unit is calculated through the frequency shift detected by the Doppler flowmeter; on each grid unit, the corresponding flow velocity value is multiplied by the area of the grid unit according to the flow velocity distribution and then summed to obtain the pipeline flow rate. The problem that the fluid in the pipeline is only partially filled under the non-full pipe condition is fully considered, and the pipeline flow rate is measured by using the actual fluid filling part. The problem of low accuracy in measuring the pipeline flow rate of a non-full flow pipeline in the prior art is solved. Description of the Drawings

[0016] Figure 1 It is a flowchart of the method for measuring the pipeline flow rate of a non-full flow pipeline in the first embodiment of the present invention; Figure 2 It is a structural block diagram of the device for measuring the pipeline flow rate of a non-full flow pipeline in the third embodiment of the present invention.

[0017] The following specific embodiments will further illustrate the present invention in conjunction with the above drawings. Specific Embodiments

[0018] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0019] It should be noted that when an element is referred to as being "fixedly provided on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for illustrative purposes.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0021] The following will specifically describe in detail how to improve the accuracy of pipeline flow measurement in a non-full-flow pipeline in combination with specific embodiments and drawings.

[0022] Embodiment 1 Please refer to Figure 1 , which shows the pipeline flow measurement method for a non-full-flow pipeline in the first embodiment of the present invention. The pipeline flow is measured by a pipeline flow measurement system. The pipeline flow measurement system includes a sonar probe floating on the water surface of the pipeline in the pipeline and a Doppler flow velocity meter placed in the flowing water area of the pipeline. The method includes steps S10 to S12.

[0023] Step S10, obtain the echo signal detected by the sonar probe, determine the target echo signal in the flowing water area of the pipeline, and determine the cross-sectional profile data and cross-sectional area of the flowing water area according to the target echo signal.

[0024] Among them, the sonar probe is used to obtain the cross-sectional shape of the flowing water area in the pipeline and collect the actual fluid filling situation in the pipeline in real time, so as to achieve accurate measurement of the pipeline flow. Specifically, the sonar probe is integrated in the sonar measurement unit, and the sonar measurement unit also includes a corresponding signal processor. The sonar probe is set in the pipeline and floats on the water surface of the pipeline. The Doppler flow velocity meter is placed in the flowing water area of the pipeline and is used for flow velocity measurement.

[0025] Specifically, the sonar probe emits acoustic wave signals into the sewage pipeline. These signals will be reflected when encountering objects in the pipeline (including water, pipe walls, etc.), forming echo signals. The sonar probe receives these reflected signals, which are the basic data for subsequent analysis. In addition to water in the pipeline, there are other parts such as pipe walls. The echo signals received by the sonar contain reflection information from various parts. Therefore, it is necessary to screen out the target echo signals from numerous echo signals. Generally, in the sewage pipeline, due to the interface between silt and water body, the sonar can distinguish silt from water body through the echo signal intensity and attenuation characteristics. Combining the intensity, propagation time, and position of the echo, the cross-sectional area of water flow can be effectively identified and the interference of silt can be excluded.

[0026] In specific implementation, the sonar emits acoustic waves, receives the reflected echoes on the target object, and measures the distance and shape of the target. In this embodiment, the sonar utilizes the reflection characteristics of acoustic waves propagating in water to obtain the cross-sectional shape.

[0027] Step S11: According to the cross-sectional profile data, the water flow area is divided into a preset number of grid cells, and the flow velocity distribution of each grid cell is calculated through the frequency shift detected by the Doppler flowmeter.

[0028] Among them, based on the obtained cross-sectional profile data of the water flow area (that is, the profile composed of a series of coordinate points describing the cross-sectional shape of the water flow area), the water flow area is divided into small grids on the cross-section. The purpose of the division is to study the water flow conditions at different positions in the water flow area more carefully. Before the grid division, the number of grid cells to be divided will be set in advance. The setting of this quantity should comprehensively consider factors such as accuracy requirements and calculation costs. If the preset quantity is large, the divided grids will be finer, which can more accurately reflect the changes in water flow in the water flow area, but the calculation amount will also increase; on the contrary, if the preset quantity is small, the grids will be sparser, the calculation amount will be small, but it may not be able to accurately capture the subtle differences in water flow. Each small grid obtained after the division is the grid cell.

[0029] Furthermore, the Doppler flowmeter is an instrument that measures the flow velocity using the Doppler effect. When it emits acoustic waves to the water flow, the acoustic waves will be reflected when encountering particles (such as suspended sediment particles, etc.) in the flowing water body. Due to the movement of the water body particles, according to the Doppler effect, the frequency of the reflected acoustic waves will change, generating a frequency shift. The faster the flow velocity, the greater the frequency shift. By measuring this frequency shift amount, the flow velocity information of the water flow can be obtained. In this embodiment, the flow velocity distribution of each grid cell is calculated according to the frequency shift.

[0030] Step S12: On each grid cell, the corresponding flow velocity value is multiplied by the area of the grid cell according to the flow velocity distribution, and then the sum is obtained to get the pipeline flow rate.

[0031] Among them, the flow velocity distribution in each grid cell is calculated through a Doppler current meter and frequency shift, that is, the water flow velocities at different positions within each small grid cell are known. When calculating the pipeline flow rate, a flow velocity value representing the grid cell needs to be determined. Generally, the average flow velocity within the grid cell can be taken, or according to the specific flow velocity distribution, a representative flow velocity value can be selected to approximately represent the water flow velocity within the entire grid cell.

[0032] For each grid cell, the determined flow velocity value is multiplied by the area of the grid cell. The grid cell area can be obtained according to the division rules and geometric calculations during grid division. What is obtained in this step is the flow contribution value of each grid cell, that is, assuming the water flow uniformly flows at the determined flow velocity within this small grid cell, the flow rate through this small area.

[0033] Since the entire water passing area is composed of multiple such grid cells, adding the flow contribution values of each grid cell is equivalent to aggregating the flow rates of each small area, and the sum obtained is the flow rate of the entire pipeline at this cross-section. By subdividing the complex water passing area into multiple simple small units, calculating the flow contribution of each small unit separately, and then accumulating to obtain the total flow rate, the actual flow rate situation within the pipeline can be accurately calculated.

[0034] In addition, in some optional embodiments of the present invention, the method further includes: Converting the signals of the sonar and Doppler current meter into corresponding numerical data through analog-to-digital conversion; Among them, the continuous signals of the sonar and Doppler current meter are sampled at time intervals to generate discrete signal values, and then the sampled signal values are mapped to finite discrete level values to be converted into corresponding numerical data.

[0035] Among them, the echo signals of sonar and Doppler current meters are usually continuous analog voltage signals, presented as waveforms that change with time (the amplitude changes with time). The characteristics of analog signals include: Amplitude: the intensity of the signal. Frequency: the change rate of the signal. Phase: the phase information of the signal. The goal of analog-to-digital conversion is to convert this continuous signal into a series of discrete digital values. Specifically, sampling is the first step of analog-to-digital conversion, mainly sampling the continuous signal at time intervals to generate discrete signal values. The frequency range of the echo signal of sonar is usually from dozens of kilohertz to hundreds of kilohertz. Therefore, the sampling frequency needs to be higher than twice the signal frequency. For example, if the highest frequency of the sonar signal is 100 kHz, the sampling frequency should be at least 200 kHz. The same applies to the Doppler current meter. Subsequently, the sampled signal values (continuous values) are mapped to a finite number of discrete values. This step decomposes the amplitude of the signal into multiple discrete level values (i.e., digitization). Finally, the quantized discrete level values can also be converted into binary format for storage or processing by a digital processor.

[0036] In summary, for the method for measuring the pipeline flow rate of a non-full-flow pipeline in the above embodiments of the present invention, by setting a sonar probe on the water surface of the pipeline in the pipeline and a Doppler current meter in the water passing area of the pipeline, the target echo signal in the water passing area of the pipeline is determined through the echo signal detected by the sonar probe, and the cross-sectional profile data and cross-sectional area of the water passing area are determined according to the target echo signal; the water passing area is divided into a preset number of grid units according to the cross-sectional profile data, and the flow velocity distribution of each grid unit is calculated through the frequency shift detected by the Doppler current meter; on each grid unit, the corresponding flow velocity value is multiplied by the area of the grid unit and then summed to obtain the pipeline flow rate. It fully considers the problem that the fluid in the pipeline is only partially filled under the non-full pipe condition, and uses the actual fluid filling part to measure the pipeline flow rate. It solves the problem of low accuracy in measuring the pipeline flow rate of non-full-flow pipelines in the prior art.

[0037] Embodiment 2 This embodiment also proposes a method for measuring the pipeline flow rate of a non-full-flow pipeline. The difference between the method for measuring the pipeline flow rate of the non-full-flow pipeline in this embodiment and the method for measuring the pipeline flow rate of the non-full-flow pipeline in Embodiment 1 is as follows: The steps of obtaining the echo signal detected by the sonar probe, determining the target echo signal in the water passing area of the pipeline, and determining the cross-sectional profile data and cross-sectional area of the water passing area according to the target echo signal include: Extracting the target echo signal from the echo signals according to the echo intensity of the echo signals; Obtaining the time difference between the target echo signals at different positions and the transmitted signal, and the propagation speed of the target echo signals to obtain the cross-sectional profile data composed of two-dimensional coordinates of discrete points inside the pipeline cross-section in multiple groups; The cross-sectional area of the corresponding water passage area obtained by calculating the definite integral using the trapezoidal method based on the cross-sectional profile data.

[0038] Among them, the sonar probe will receive echo signals containing various information, and these signals come from the reflections of different objects (such as water, pipe wall, impurities, etc.) inside the pipeline. Since different objects have different reflection abilities for sound waves, the echo intensities are also different. For example, the water and the pipe wall material are different, and the intensities of the reflected sound waves are different. By setting an appropriate intensity threshold, the target echo signals that can represent the water passage area can be screened out. In a sewage pipeline, due to the interface between the silt and the water body, the sonar can distinguish the silt from the water body through the echo signal intensity and attenuation characteristics. In small sewage or drainage pipelines with a diameter of 0.2 m to 1 m, the transmitted signal intensity is: 180 dB to 200 dB. The echo signal intensity is: liquid surface reflection: 100 dB to 130 dB. Pipe wall reflection: 90 dB to 120 dB. Debris or sediment reflection: 60 dB to 100 dB.

[0039] After the sonar emits a signal, the target echo signals return from different positions inside the pipeline at different times. Given the propagation speed of sound waves in water (or the corresponding medium), according to the distance calculation formula, the distance from the signal reflection point to the sonar probe can be calculated from the time difference between the target echo signal and the transmitted signal.

[0040] On a two-dimensional plane, combining information such as the position and angle of the sonar probe, using geometric relationships, these distance information are converted into the two-dimensional coordinates of discrete points inside the pipeline cross-section. The coordinates of multiple discrete points are combined to form the cross-sectional profile data describing the pipeline cross-section. And the cross-sectional area of the corresponding water passage area obtained by calculating the definite integral using the trapezoidal method based on the cross-sectional profile data. Specifically, the cross-section of the water passage area can be approximately regarded as composed of multiple small trapezoids. Connect the adjacent discrete points to form small trapezoids, calculate the area of each small trapezoid according to the trapezoid area formula, and then accumulate the areas of these small trapezoids (equivalent to calculating the definite integral), and the sum obtained is the cross-sectional area of the water passage area. Exemplarily, the calculation formula for the cross-sectional area of the water passage area is: ; Among them, a, b is the integration interval, f ( x i ) is the function value corresponding to the integration interval x i , which can be obtained from the two-dimensional coordinates of the discrete points. h is the step size, and the integration interval [a, b] is evenly divided into N sub-intervals. h = ( b - a ) / N , N is the number of divided intervals.

[0041] In addition, in some alternative embodiments of the present invention, the step of dividing the water passing area into a preset number of grid units according to the cross-sectional profile data and calculating the flow velocity distribution of each grid unit by detecting the frequency shift with a Doppler flow velocity meter includes: Defining the grid range of the water passing area according to the maximum and minimum values of the two-dimensional coordinates of the discrete points; Dividing the cross-section of the water passing area into two-dimensional grid units and determining the coordinates of each grid unit according to the grid resolution; Determining the central velocity of the graphic center of the water passing area by the frequency shift detected by the Doppler flow velocity meter, and determining the distance from the graphic center to each grid unit according to the coordinates of each grid unit and the coordinates of the graphic center; Calculating and interpolating the flow velocity distribution of each grid unit by the inverse distance weighting method with the distance from the graphic center to each grid unit weighted according to the central velocity.

[0042] Among them, when the fluid flows in the pipeline, due to the viscous effect, the flow velocities at various points on the cross-section of the pipeline are different. Specifically, the closer to the pipe wall, due to the viscous effect between the fluid and the pipe wall, the smaller the flow velocity, and the flow velocity on the pipe wall is zero; the closer to the pipe center, due to the smaller viscous effect between the fluid and the pipe wall, the larger the flow velocity, and the flow velocity at the pipe center is the largest. This distribution pattern is called the pipeline velocity distribution. Therefore, the inverse distance weighting method is used to calculate the flow velocity distribution.

[0043] Specifically, since the cross-sectional profile data composed of the two-dimensional coordinates of multiple sets of discrete points inside the pipeline cross-section has been obtained. Among the two-dimensional coordinates of these discrete points, find x the maximum and minimum values of the coordinates, and y the maximum and minimum values of the coordinates. These four extreme values determine the grid range, and this grid range is the cross-section of the actual water passing area, which also defines the boundary of the area for subsequent grid division. Within the defined grid range, divide the cross-section of the water passing area into two-dimensional grids. The grid resolution refers to the size of each grid (such as the side length), which is a preset parameter. According to this resolution and in combination with the grid range, the specific coordinates of each grid in the two-dimensional plane can be calculated.

[0044] The Doppler flow velocity meter determines the flow velocity by measuring the frequency shift. Using the measured frequency shift data, through relevant calculations, the velocity of the graphic center of the water passing area (which can be understood as the geometric center position of the entire cross-section of the water passing area) can be determined, and this velocity is called the central velocity.

[0045] Specifically, the calculation formula for the central velocity is: ; Among them, For the graphic center frequency shift in the water passing area, f t is the transmitting frequency of the Doppler current meter, c is the propagation speed of sound waves in the fluid, θ is the angle between the sound wave propagation direction and the particle movement direction in the fluid.

[0046] The coordinates of each grid cell and the coordinates of the graphic center have been determined. According to the distance formula between two points in the plane rectangular coordinate system, the distance from the graphic center to each grid cell can be calculated. Based on the center velocity of the graphic center, the center velocity is weighted according to the distance from the graphic center to each grid cell. The grid cells closer to the graphic center are more affected by the center velocity and have a greater weight; the grid cells farther away have a smaller weight. By this way of weighted calculation and interpolation, a flow velocity value is determined for each grid cell, and thus the flow velocity distribution of each grid cell in the entire water passing area is obtained, that is, the flow velocity magnitude of the water flow at different grid positions is known. Exemplarily, the calculation formula of the inverse distance weighted method is: ; wherein, is the reciprocal of the Euclidean distance between the i th grid cell and the graphic center, n is the number of grid cells, is the center velocity of the corresponding graphic center, is the flow velocity value of the target grid cell to be calculated.

[0047] In summary, for the method for measuring the pipeline flow rate of the non-full-flow pipeline in the above embodiments of the present invention, by setting a sonar probe on the water surface of the pipeline in the pipeline, and a Doppler current meter in the water passing area of the pipeline, the target echo signal in the water passing area of the pipeline is determined through the echo signal detected by the sonar probe, and the cross-sectional contour data and cross-sectional area of the water passing area are determined according to the target echo signal; the water passing area is divided into grid cells with a preset number according to the cross-sectional contour data, and the flow velocity distribution of each grid cell is calculated through the frequency shift detected by the Doppler current meter; on each grid cell, the pipeline flow rate is obtained by summing the product of the corresponding flow velocity value and the area of the grid cell according to the flow velocity distribution. The problem that the fluid in the pipeline is only partially filled under the non-full pipe condition is fully considered, and the pipeline flow rate is measured by using the actual fluid filling part. The problem of low accuracy in measuring the pipeline flow rate of the non-full-flow pipeline in the prior art is solved.

[0048] Embodiment III Please refer to Figure 2, shown is a pipeline flow measurement device for an open-channel pipeline proposed in the third embodiment of the present invention. The pipeline flow is measured by a pipeline flow measurement system. The pipeline flow measurement system includes a sonar probe floating on the water surface inside the pipeline and a Doppler velocimeter placed in the flowing water area inside the pipeline. The device includes: An acquisition module 100, configured to acquire the echo signal detected by the sonar probe, determine the target echo signal in the flowing water area of the pipeline, and determine the cross-sectional contour data and cross-sectional area of the flowing water area according to the target echo signal; A division module 200, configured to perform grid division on the flowing water area according to the cross-sectional contour data to obtain a preset number of grid units, and calculate the flow velocity distribution of each grid unit through the frequency shift detected by the Doppler velocimeter; A measurement module 300, configured to sum the product of the corresponding flow velocity value and the area of the grid unit on each grid unit to obtain the pipeline flow.

[0049] The functions or operation steps implemented when the above modules are executed are substantially the same as those in the above method embodiments, and will not be elaborated here.

[0050] Embodiment Four On the other hand, the present invention also provides a readable storage medium, on which a computer program is stored. When the program is executed by a processor, the steps of the method according to any one of the above Embodiments 1 to 2 are implemented.

[0051] Embodiment Five On the other hand, the present invention also provides an electronic device. The electronic device includes a memory, a processor, and a computer program stored on the memory and running on the processor. When the processor executes the program, the steps of the method according to any one of the above Embodiments 1 to 2 are implemented.

[0052] The technical features of each of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0053] Those skilled in the art will understand that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a definite sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable storage medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or used in combination with these instruction execution systems, apparatus, or devices. For the purposes of this specification, a "computer-readable storage medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

[0054] More specific examples (non-exhaustive list) of computer-readable storage media include the following: an electrical connection part with one or more wirings (electronic device), a portable computer diskette case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, a computer-readable storage medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation, or other appropriate processing as necessary, and then stored in a computer memory.

[0055] It should be understood that various parts of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits with logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits with appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0056] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0057] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent for the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention shall be subject to the appended claims.

Claims

1. A method for measuring flow rate in a non-full flow pipeline, characterized in that: The pipeline flow rate of a non-full flow pipeline is measured by a pipeline flow measurement system, wherein the pipeline flow measurement system includes a sonar probe arranged in the pipeline and floating on the water surface of the pipeline, and a Doppler flow meter placed in a water flow area in the pipeline. The method includes: Acquire the echo signal detected by the sonar probe, determine the target echo signal of the water-passing area in the pipeline, and determine the cross-sectional profile data and cross-sectional area of ​​the water-passing area based on the target echo signal; The water flow area is grid-divided into a preset number of grid cells according to the cross-sectional profile data, and the velocity distribution of each grid cell is calculated by the frequency shift detected by the Doppler flow meter; On each grid unit, the corresponding flow velocity value is multiplied by the area of ​​the grid unit according to the flow velocity distribution, and the sum is obtained to obtain the pipeline flow.

2. The method for measuring flow rate in a non-full flow pipeline according to claim 1, characterized in that: The steps of acquiring the echo signal detected by the sonar probe, determining the target echo signal of the water-passing area in the pipeline, and determining the cross-sectional profile data and the cross-sectional area of ​​the water-passing area according to the target echo signal include: Extracting the target echo signal from the echo signal according to the echo strength of the echo signal; Obtain the time difference between the target echo signal and the transmission signal at different positions and the propagation speed of the target echo signal to obtain the cross-sectional profile data composed of two-dimensional coordinates of multiple groups of discrete points inside the pipeline cross section; The cross-sectional area of ​​the corresponding water flow region is obtained by calculating the definite integral using the trapezoidal method according to the cross-sectional profile data.

3. The method for measuring flow rate in a non-full flow pipeline according to claim 2, characterized in that: The calculation formula for the cross-sectional area of ​​the water flow area is: ； in,[ a,b ] is the integration interval, f ( x i ) is the integral interval x i The corresponding function value can be obtained from the two-dimensional coordinates of the discrete points. h is the step size, and the integration interval [a,b] is evenly divided into N sub-intervals, h =( ba ) / N , N is the number of partition intervals.

4. The method for measuring flow rate in a non-full flow pipeline according to claim 2, characterized in that: The step of dividing the water flow area into grids according to the cross-sectional profile data to obtain a preset number of grid units, and calculating the flow velocity distribution of each grid unit by the frequency shift detected by the Doppler flow meter comprises: The grid range of the water-passing area is defined according to the maximum and minimum values ​​of the two-dimensional coordinates of the discrete points; The cross section of the water-passing area is divided into two-dimensional grid cells, and the coordinates of each grid cell are determined according to the grid resolution; The central velocity of the center of the graphic in the water-passing area is determined by the frequency shift detected by the Doppler current meter, and the distance from the center of the graphic to each grid unit is determined according to the coordinates of each grid unit and the coordinates of the center of the graphic; According to the central velocity, the flow velocity distribution of each grid cell is obtained by interpolation using the inverse distance weighted method with the distance from the center of the graphic to each grid cell.

5. The method for measuring flow rate in a non-full flow pipeline according to claim 4, characterized in that: The calculation formula of the center speed is: ； in, is the center frequency shift of the graph in the water-passing area, f t is the transmitting frequency of the Doppler flowmeter, c is the propagation speed of sound waves in the fluid, θ It is the angle between the direction of sound wave propagation and the direction of particle movement in the fluid.

6. The method for measuring flow rate in a non-full flow pipeline according to claim 4, characterized in that: The calculation formula of the inverse distance weighted method is: ； in, For the i The reciprocal of the Euclidean distance between a grid cell and the center of the shape, n is the number of grid cells, is the central velocity of the corresponding graphics center, is the flow velocity value of the target grid cell that needs to be calculated.

7. The method for measuring flow rate in a non-full flow pipeline according to claim 1, characterized in that: The method further comprises: Convert the signals of sonar and Doppler current meter into corresponding numerical data through analog-to-digital conversion; The continuous sonar and Doppler current meter signals are sampled at time intervals to generate discrete signal values, and then the sampled signal values ​​are mapped to finite discrete level values ​​to be converted into corresponding numerical data.

8. A pipeline flow measurement device for a non-full flow pipeline, characterized in that: The pipeline flow rate of the non-full flow pipeline is measured by a pipeline flow measurement system, the pipeline flow measurement system includes a sonar probe arranged in the pipeline and floating on the water surface of the pipeline, and a Doppler flow meter placed in the water flow area of ​​the pipeline, the device includes: An acquisition module is used to acquire the echo signal detected by the sonar probe, determine the target echo signal of the water-passing area in the pipeline, and determine the cross-sectional profile data and cross-sectional area of ​​the water-passing area according to the target echo signal; A division module is used to divide the water flow area into a grid according to the cross-sectional profile data to obtain a preset number of grid units, and calculate the flow velocity distribution of each grid unit through the frequency shift detected by the Doppler flow meter; The measuring module is used to multiply the corresponding flow velocity value by the area of ​​the grid unit according to the flow velocity distribution on each grid unit and then sum them up to obtain the pipeline flow rate.

9. A readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. An electronic device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of the method according to any one of claims 1 to 7 when executing the program.

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