CN-122017281-A - Non-straight pipeline gas flow velocity measurement system

CN122017281ACN 122017281 ACN122017281 ACN 122017281ACN-122017281-A

Abstract

The application relates to the technical field of flow velocity measurement, in particular to a non-straight pipeline gas flow velocity measurement system which comprises an acoustic detection module, a signal processing module, a flow field reconstruction module and a flow field analysis module, wherein the acoustic detection module comprises a plurality of acoustic sensors which are arranged outside a target pipeline section and are used for forming acoustic detection paths outside the pipeline, the signal processing module is used for receiving acoustic signals sent by the acoustic detection module, carrying out amplitude analysis and transit time calculation on the acoustic signals to obtain gas flow velocity path integral measurement data of each path, the flow field reconstruction module is used for carrying out inversion calculation on the path integral measurement data by adopting an improved acoustic tomography algorithm fused with a non-straight pipeline turbulence model, reconstructing a two-dimensional flow velocity distribution field of a cross section to be measured, and the flow field analysis module is used for carrying out intelligent data analysis on the two-dimensional flow velocity distribution field, extracting and outputting flow velocity key information. The application solves the technical problem of providing reliable distribution information of the section flow velocity in the non-straight pipeline in the prior art.

Inventors

LI SHUANG
Wu Quanchao
HE QIAN
WANG ZHENGSHU
Zhou xinjiang
LUO NAN
WANG ZHEN

Assignees

北京首创生态环保集团股份有限公司

Dates

Publication Date: 20260512
Application Date: 20251230

Claims (10)

1. A non-straight conduit gas flow rate measurement system, comprising: The acoustic detection module comprises a plurality of acoustic sensors which are arranged outside the target pipeline section, wherein the plurality of acoustic sensors are paired in pairs to form a plurality of sensor pairs, and the plurality of acoustic sensor pairs are used for forming a plurality of acoustic detection paths which cross through the pipeline from different space angles and pass through the same cross section to be detected inside the pipeline; the signal processing module is used for receiving the acoustic signals sent by the acoustic detection module, carrying out amplitude analysis and transit time calculation on the acoustic signals, and obtaining gas flow velocity path integral measurement data of each path; The flow field reconstruction module is used for carrying out inversion calculation on the path integral measurement data by adopting an improved acoustic tomography algorithm fused with a non-straight pipe turbulence model to reconstruct a two-dimensional flow velocity distribution field of a cross section to be measured; The flow field analysis module is used for carrying out intelligent data analysis on the two-dimensional flow velocity distribution field, extracting and outputting flow velocity key information, wherein the flow velocity key information comprises flow velocity statistical characteristic values covering a designated area in a cross section to be detected and a flow velocity distribution visual cloud image.
2. The non-straight conduit gas flow rate measurement system according to claim 1, wherein, The plurality of acoustic sensors are distributed outside the target pipeline section by adopting an adjustable mounting bracket, the plurality of acoustic sensors are distributed in an annular array, the circle center of the annular array coincides with the axis of the pipeline, and the opening angle of the adjacent sensor is smaller than or equal to 15 degrees.
3. The non-straight conduit gas flow rate measurement system of claim 1, wherein the signal processing module comprises: the signal adjusting unit is used for carrying out filtering and amplifying pretreatment on the acoustic signals received by the acoustic sensor to obtain pretreated signals; The data acquisition unit is used for converting the preprocessed signals into digital signals; The transit time resolving unit is used for analyzing the digital signals by adopting a cross-correlation algorithm, respectively calculating transit time of the sound waves propagating along the forward flow direction and the backward flow direction of each sensor, and obtaining a transit time difference; and the path integral calculation unit is used for obtaining the gas flow velocity path integral measurement data on each acoustic detection path according to the transit time difference and the corresponding space geometric relationship and the acoustic time difference method principle.
4. A non-straight pipe gas flow rate measurement system according to claim 3, wherein the transit time calculation unit is specifically configured to: for each sensor pair, the following steps are performed: acquiring a downstream digital signal and a countercurrent digital signal; respectively calculating a first cross-correlation function of the downstream digital signal and a standard reference signal and a second cross-correlation function of the upstream digital signal and the standard reference signal; Detecting main peak values of the first cross-correlation function and the second cross-correlation function respectively, and determining forward flow transit time and reverse flow transit time; And acquiring a transition time difference according to the forward transition time and the backward transition time.
5. The non-straight pipe gas flow rate measurement system of claim 1, wherein the flow field reconstruction module comprises: The flow field initializing unit is used for establishing an initial two-dimensional flow velocity distribution field based on the geometric structure parameter and the fluid attribute parameter of the target pipeline section; The model fusion unit is used for embedding the non-straight pipeline turbulence model into an acoustic tomography inversion algorithm in a priori constraint mode, wherein the non-straight pipeline turbulence model is used for describing flow field asymmetry and vortex characteristics caused by pipeline bending or structure mutation; And the iterative inversion unit is used for taking the path integral measurement data as input, carrying out iterative correction on the initial two-dimensional flow velocity distribution field by using an acoustic tomography inversion algorithm embedded into a turbulence model until the error between the theoretical path integral value corresponding to the reconstructed two-dimensional flow velocity distribution field and the actual measurement data is smaller than a set threshold value, and outputting the finally reconstructed two-dimensional flow velocity distribution field.
6. The non-straight pipe gas flow rate measurement system according to claim 5, wherein the iterative inversion unit is specifically configured to perform inversion calculation by: Starting an iterative process based on the initial two-dimensional flow velocity distribution hypothesis field and the path integral measurement data, and in each iterative step, performing the following operations: Forward calculation is carried out based on the estimated value of the two-dimensional flow velocity distribution field of the current iteration to obtain a corresponding theoretical path integral value set; The prior constraint of the non-straight pipe turbulence model is combined, correction of the estimated value of the current two-dimensional flow velocity distribution field is obtained through an optimization algorithm, and the estimated value of the two-dimensional flow velocity distribution field is updated; And repeating the iterative process until the data fitting residual error is smaller than a set threshold value or the iterative times reach a preset upper limit, and outputting the two-dimensional flow velocity distribution estimated value obtained at the moment as the finally reconstructed two-dimensional flow velocity distribution field.
7. The non-straight pipe gas flow rate measurement system of claim 1, wherein the flow field analysis module comprises: The flow field characteristic extraction unit is used for identifying and quantifying specific flow field characteristics caused by a pipeline non-straight section structure from the two-dimensional flow velocity distribution field, wherein the specific flow field characteristics comprise an asymmetry index of flow velocity distribution, the central position and intensity of one or more vortex structures and an actual flow direction angle synthesized by a main flow and a secondary flow; and the comprehensive diagnosis and output unit is used for acquiring flow statistics values of a designated area in the cross section to be detected based on the two-dimensional flow velocity distribution field and the specific flow field characteristics, and generating a flow velocity distribution visual cloud chart fused with the specific flow field characteristic labels.
8. The non-straight pipeline gas flow rate measurement system according to claim 7, wherein the integrated diagnosis and output unit is configured to obtain a flow statistic of a specified area in a cross section to be measured based on the two-dimensional flow rate distribution field and the specific flow field feature, specifically including: According to the actual flow direction angle in the specific flow field characteristics, converting and synthesizing two-dimensional plane flow velocity vectors of each grid unit in the two-dimensional flow velocity distribution field into axial flow velocity components of each grid unit along the axial direction of the pipeline, and generating an axial flow velocity component distribution field of the cross section to be detected; defining the specified area in the cross section to be measured based on the specific flow field characteristics, wherein the specified area comprises a core flow area indicated by the asymmetry index, a vortex influence area taking the central position of the vortex structure as the center and a secondary flow significant area defined by the actual flow direction angle; and extracting and calculating flow velocity statistical characteristic values in each specified region based on the axial flow velocity component distribution field, wherein the flow velocity statistical characteristic values comprise a region average axial flow velocity, a region axial flow velocity standard deviation and a region maximum reverse flow velocity.
9. The non-straight conduit gas flow rate measurement system of claim 8, wherein the integrated diagnostic and output unit is further configured to: defining a core flow region comprising a main flow high-speed region and a corresponding low-speed backflow region as the designated region when the asymmetry index exceeds a first threshold; when the strength of the vortex structure exceeds a second threshold value, a vortex influence area within a preset radius range is defined as the appointed area by taking the vortex center as a circle center; And according to the spatial distribution of the actual flow direction angle in the cross section, defining a region with the actual flow direction angle deviating from the axial direction of the pipeline by more than a third threshold value as a secondary flow significant region as the appointed region.
10. The non-straight pipeline gas flow rate measurement system of claim 1 further comprising a real-time adaptive calibration module comprising: the model-flow field matching degree evaluation unit is used for continuously monitoring time-varying characteristics of the two-dimensional flow velocity distribution field output by the flow field reconstruction module and dynamically evaluating matching degree of the non-straight pipe turbulence model used in the current inversion calculation and the current actual flow field; The model parameter on-line optimization unit is used for triggering an on-line calibration process when judging that the matching degree is lower than a preset threshold value, and performing inverse problem optimization on key model parameters in the non-straight pipeline turbulence model to obtain optimized model parameters, wherein the key model parameters comprise one or more of boundary layer speed profile indexes, turbulence vortex viscosity coefficients and secondary flow intensity coefficients; and the model parameter dynamic updating unit is used for feeding the optimized model parameters back to the flow field reconstruction module in real time so as to update the embedded prior constraint.

Description

Non-straight pipeline gas flow velocity measurement system Technical Field The application relates to the technical field of flow velocity measurement, in particular to a non-straight pipeline gas flow velocity measurement system. Background In the fields of industrial production, energy transportation, environmental monitoring and the like, it is important to accurately measure the gas flow velocity in a pipeline, especially when a pipeline has a bent pipe, a variable diameter or a converging pipe and other non-straight pipe sections, the internal flow field of the pipeline can present complicated spatial distribution characteristics, such as asymmetric flow velocity profile, secondary flow and even vortex structure, due to inertia, centrifugal force and wall effect. The two-dimensional flow velocity distribution of the cross section is accurately mastered, and the method has important significance for evaluating flow loss, optimizing system energy efficiency and guaranteeing equipment safety. Currently, the prior art relies primarily on single point measurements or line average measurements based on specific flow assumptions for the measurement of the conduit gas flow rate. Specifically, one common technique is to employ an invasive probe such as a pitot tube, a thermal anemometer, or the like. According to the method, the probe needs to be stretched into the flow field, so that the structure of the flow field to be measured can be disturbed or even changed, the real state is difficult to reflect, the flow velocity of the local point where the probe is located can be obtained, and the flow velocity distribution information of the whole cross section can not be obtained efficiently and undisturbed. Another widely used class of technology is gas flow meters based on ultrasonic jet lag methods. This type of technique relies on the time difference between forward and backward propagation of sound waves to estimate the average flow velocity along the channel direction, the measurement of which is essentially the line integral value over one acoustic path. In order to obtain a cross-sectional average flow velocity and thus calculate the volumetric flow rate, this type of technique generally requires the assumption that the flow velocity in the cross-section of the pipe is regularly distributed in an axisymmetric manner. However, in non-straight pipes, the flow velocity profile deviates significantly from the rule assumptions due to the aforementioned complex flow phenomena, so that the ultrasonic time difference method based on such assumptions will introduce significant measurement errors and fail to provide reliable cross-sectional flow velocity profile information. Therefore, there is a need for an off-line gas flow rate measurement system. Disclosure of Invention First, the technical problem to be solved In view of the above-mentioned drawbacks and shortcomings of the prior art, the present application provides a non-straight pipeline gas flow velocity measurement system, which solves the technical problem of providing reliable cross-sectional flow velocity distribution information in a non-straight pipeline in the prior art. (II) technical scheme In order to achieve the above purpose, the main technical scheme adopted by the application comprises the following steps: The embodiment of the application provides a non-straight pipeline gas flow velocity measurement system, which comprises: The acoustic detection module comprises a plurality of acoustic sensors which are arranged outside the target pipeline section, wherein the plurality of acoustic sensors are paired in pairs to form a plurality of sensor pairs, and the plurality of acoustic sensor pairs are used for forming a plurality of acoustic detection paths which cross through the pipeline from different space angles and pass through the same cross section to be detected inside the pipeline; the signal processing module is used for receiving the acoustic signals sent by the acoustic detection module, carrying out amplitude analysis and transit time calculation on the acoustic signals, and obtaining gas flow velocity path integral measurement data of each path; The flow field reconstruction module is used for carrying out inversion calculation on the path integral measurement data by adopting an improved acoustic tomography algorithm fused with a non-straight pipe turbulence model to reconstruct a two-dimensional flow velocity distribution field of a cross section to be measured; The flow field analysis module is used for carrying out intelligent data analysis on the two-dimensional flow velocity distribution field, extracting and outputting flow velocity key information, wherein the flow velocity key information comprises flow velocity statistical characteristic values covering a designated area in a cross section to be detected and a flow velocity distribution visual cloud image. Optionally, in some embodiments of the present application, the pluralit