A method and system for measuring the cross-sectional distribution of microbubbles in a tube

Abstract

The application discloses a kind of in-pipe micron bubble cross-section distribution measurement method and system, comprising: at the target cross section of the pipeline to be measured, multiple electric conductance probes are arranged along the circumferential direction of the pipeline, and the needle tip of each electric conductance probe extends into the interior of the pipeline at different radial depths;Make the measured fluid containing micron bubbles flow through the pipeline to be measured, measure the flow rate of the measured fluid, and synchronously collect the voltage falling edge signal output by each electric conductance probe within a preset sampling duration to obtain the number of voltage falling edge signals corresponding to each electric conductance probe;Based on the flow rate of the measured fluid, the number of voltage falling edge signals corresponding to each electric conductance probe and the effective sensitive area parameter of the needle tip of the electric conductance probe calibrated in advance for bubble contact event, the distribution information of micron bubbles on the target cross section is calculated.The purpose of the present application is to realize the online cross-section distribution measurement of micron bubbles in opaque metal industrial pipelines, meet the actual needs, overcome the limitations of existing technical means, such as dependence on the light transmittance of the pipeline, destruction of the flow field continuity during the measurement process, and inability to achieve true online transient monitoring and capture of bubble distribution dynamic change rules.

Description

Technical Field

[0001] This invention belongs to the field of micron bubble measurement technology, specifically relating to a method and system for measuring the cross-sectional distribution of micron bubbles inside a tube. Background Technology

[0002] In numerous industrial and scientific research fields, such as oil extraction, chemical processes, environmental engineering, and biomedicine, the precise measurement of micron-sized bubbles within pipelines has become a critical requirement. Taking microbubble enhanced oil recovery (EOR) technology as an example, its effectiveness in enhancing oil recovery is closely related to the uniformity, density, and dynamic evolution of the injected bubbles within the porous media of the core or pipeline. Accurately understanding the bubble distribution information on the pipeline cross-section is an indispensable step in optimizing process parameters and evaluating displacement efficiency.

[0003] However, existing technologies have limitations in measuring the online cross-sectional distribution of micron-sized bubbles in opaque metal industrial pipes, making it difficult to meet practical needs. Specifically: (1) Observation methods relying on optical principles, such as high-speed photography, require the pipe or flow field being measured to be transparent. This is still applicable in transparent model tubes in the laboratory, but it cannot penetrate stainless steel and other metal pipes widely used in industrial settings, leading to measurement failure. (2) Methods such as the quick-closing valve method, which require interrupting the flow for sampling and analysis, can obtain cross-sectional information at a certain moment, but their measurement process disrupts the continuity of the flow field, making it impossible to achieve true online transient monitoring and thus unable to capture the dynamic changes in bubble distribution during the flow process. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a method and system for measuring the cross-sectional distribution of micron-sized bubbles inside pipes. The purpose is to achieve online measurement of the cross-sectional distribution of micron-sized bubbles inside opaque metal industrial pipes, meet practical needs, and overcome the limitations of existing technologies that rely on the light transmittance of the pipes and disrupt the continuity of the flow field during the measurement process, thus failing to achieve true online transient monitoring and capture of the dynamic changes in bubble distribution.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: According to a first aspect of the present invention, a method for measuring the cross-sectional distribution of micron-sized bubbles inside a tube is provided, comprising: At the target cross-section of the pipe to be tested, multiple conductivity probes are arranged along the circumference of the pipe, and the tip of each conductivity probe extends into the pipe at a different radial depth. The test fluid containing micron-sized bubbles is passed through the test pipe, the flow velocity of the test fluid is measured, and the voltage falling edge signal output by each conductivity probe within a preset sampling time is collected simultaneously to obtain the number of voltage falling edge signals corresponding to each conductivity probe. Based on the flow velocity of the fluid under test, the number of voltage drop edges corresponding to each conductivity probe, and the pre-calibrated effective sensitive area parameters of the probe tip for bubble contact events, the distribution information of micron-sized bubbles on the target cross-section is calculated.

[0006] In one possible implementation of the first aspect, the method for calibrating the effective sensitive area parameter of the conductivity probe tip for a bubble contact event includes: At least one conductivity probe is arranged on the calibration pipe with a visible observation section, the tip of the conductivity probe extending radially into the calibration pipe; The calibration fluid containing micron-sized air bubbles flows through the calibration pipe, and the process is performed synchronously: The first number of bubbles that actually come into contact at the needle tip is collected using a high-speed imaging system. The second number of voltage drop edges triggered by the bubble contact event is acquired by the electrical signal acquisition system. Based on the first quantity, the second quantity, and the flow rate of the calibration fluid, the effective sensitive area parameter of the needle tip for bubble contact events is determined.

[0007] In one possible implementation of the first aspect, determining the effective sensitive area parameter of the needle tip for a bubble contact event based on the first quantity, the second quantity, and the fluid flow rate specifically involves:

[0008] In the formula, The effective sensitive area parameter of the calibrated needle tip for bubble contact events; The first quantity; The second quantity; To calibrate the flow rate of the fluid.

[0009] In one possible implementation of the first aspect, the plurality of conductivity probes are arranged at equal intervals along the circumference of the pipe, and the tips of the plurality of conductivity probes are arranged at equal intervals along the radial direction of the pipe.

[0010] In one possible implementation of the first aspect, the distribution information of the microbubbles on the target cross-section includes at least: The total number of micron-sized bubbles contained in a unit volume of fluid on the target cross-section. In one possible implementation of the first aspect, the specific formula for calculating the total number of micron-sized bubbles contained in a unit volume of fluid on the target cross-section is as follows:

[0011] In the formula, The total number of micron-sized bubbles contained in a unit volume of fluid on the target cross-section; This refers to the number of conductivity probes; The velocity of the fluid to be measured; For the first i The number of voltage falling edges corresponding to the root conductivity probe within a preset sampling time; For the first i The effective sensitive area parameter of the tip of the conductivity probe for bubble contact events; This is the preset sampling duration.

[0012] In one possible implementation of the first aspect, the flow rate of the fluid to be tested is measured by a mass flow meter installed on the pipe to be tested.

[0013] According to a second aspect of the present invention, an in-tube microbubble cross-sectional distribution measurement system is provided for implementing the aforementioned method for measuring the cross-sectional distribution of microbubbles in a tube, comprising: The probe array module includes a fixed base and conductive probes mounted on the fixed base. The probe array module is used to be installed at the target cross-section of the pipe to be tested, and the tips of multiple conductive probes are inserted into the pipe at different radial depths. The signal acquisition and processing module is electrically connected to the probe array module and is used to acquire and process the voltage falling edge signal; The flow measurement module is used to acquire the flow velocity of the fluid in the pipe under test in real time. The data processing module, which is communicatively connected to the signal acquisition and processing module and the flow measurement module, is configured to: calculate the distribution information of micron-sized bubbles on the target cross-section based on the flow velocity of the fluid under test, the number of voltage drop edges corresponding to each conductivity probe, and the effective sensitive area parameters of the probe tip for bubble contact events pre-calibrated.

[0014] In one possible implementation of the second aspect, the probe array module further includes a sealing sleeve and a locking component, wherein the conductivity probe passes through the sealing sleeve through the fixed base, and the locking component adjusts and fixes the radial depth of its tip extending into the pipe to be tested.

[0015] One possible implementation of the second aspect also includes: The calibration module, used to calibrate a single conductivity probe before performing a measurement, includes a high-voltage window unit, a high-speed imaging unit, and a synchronization control unit, used to acquire the effective sensitive area parameters; The high-pressure viewing window unit is a transparent pipe section with the same diameter as the pipe to be tested, and the high-speed imaging unit focuses on the tip area of ​​the conductivity probe.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: This invention provides a method for measuring the cross-sectional distribution of micron-sized bubbles inside a pipe. By simultaneously measuring with multiple probes at different depths along the pipe cross-section, it achieves online transient measurement of the distribution of micron-sized bubbles in opaque pipes. Employing the principle of contact induction using conductivity probes, the measurement is completely light-independent and can be directly applied to common metal pipes in industrial settings, solving the problem of the inability to visually observe bubbles in opaque pipes. It achieves true online transient measurement; the entire measurement process does not require interruption of fluid flow. By synchronously acquiring signals under the flow state, it can capture the dynamic changes in bubble distribution in real time, overcoming the limitations of methods such as the quick-closing valve method that disrupt the flow field continuity. By arranging multiple probes radially, data from different locations from the pipe center to the pipe wall can be acquired simultaneously, thereby reconstructing the bubble distribution across the entire cross-section, providing a more comprehensive reflection of the flow field characteristics compared to single-point measurements.

[0017] Fourth, it improves the applicability for measuring micron-sized bubbles. By introducing a pre-calibrated effective sensitive area parameter, the physical characteristics of the contact between the microbubble and the needle tip are considered in the calculation, which improves the accuracy of interpreting microbubble collision event signals and the reliability of measurement. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating a method for measuring the cross-sectional distribution of micron-sized bubbles inside a tube, as described in an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of a probe array module in a tube micron bubble cross-sectional distribution measurement system according to an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of a tube-based micron bubble cross-sectional distribution measurement system according to an embodiment of the present invention.

[0022] Figure 4 This is a flowchart illustrating the measurement procedure for a method of measuring the cross-sectional distribution of micron-sized bubbles inside a tube, as described in an embodiment of the present invention.

[0023] Figure 5 The voltage signal measured in the embodiment of the present invention is shown. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] like Figure 1 As shown, this invention provides a method for measuring the cross-sectional distribution of micron-sized bubbles inside a tube, specifically including the following steps: S1. At the target cross-section of the pipe to be tested, multiple conductivity probes are arranged along the circumference of the pipe, and the tip of each conductivity probe extends into the pipe to a different radial depth.

[0026] In detail, the pipe to be tested is an opaque metal pipe. A target cross-section is selected on this opaque metal pipe to be measured. Multiple mounting holes are evenly distributed along the circumference of the pipe wall at this cross-section. A mounting base (such as...) is used to fix the pipe. Figure 2 As shown, install conductivity probes into these holes. During installation, ensure that the tip of each probe extends radially into the pipe, and that the radial depth of each probe tip is different. For example, if three probes are arranged, one tip can extend near the pipe wall, one can extend near the midpoint of the pipe radius, and the other can extend near the center of the pipe. The tips of all probes are exposed and in direct electrical contact with the fluid inside the pipe, while the probe bodies are isolated and fixed to the pipe wall by insulating and sealing components such as PTFE sleeves.

[0027] S2. The test fluid containing micron-sized bubbles is allowed to flow through the test pipe, the flow rate of the test fluid is measured, and the voltage falling edge signal output by each conductivity probe within a preset sampling time is collected simultaneously to obtain the number of voltage falling edge signals corresponding to each conductivity probe.

[0028] In other words, after the preparation is complete, the fluid containing micron-sized bubbles (e.g., water and air) to be measured is continuously flowed through the pipe, maintaining a flow state free from measurement interference. During this process, two measurements are performed simultaneously: first, the mass flow rate of the fluid is monitored by a mass flow meter installed on the pipe, and the average flow velocity of the fluid is calculated by combining the known pipe inner diameter and fluid density; second, the signal acquisition system is activated to simultaneously acquire the electrical signal output by each conductivity probe within a preset sampling time.

[0029] When a micron-sized bubble in a fluid moves with the flow and comes into contact with the tip of a probe, the conductivity of the bubble is much lower than that of the liquid, causing a momentary increase in the resistance of the probe circuit. This generates a distinctive voltage drop pulse at the signal terminal, such as... Figure 5As shown, the signal acquisition system captures and records these voltage falling edge signals in real time.

[0030] After sampling, the flow rate calculated by the flow meter and the number of voltage drop edges generated by each probe during the sampling time were obtained, denoted as , i= 1,2,..., N , N This represents the total number of probes.

[0031] S3. Based on the flow velocity of the fluid under test, the number of voltage drop edges corresponding to each conductivity probe, and the pre-calibrated effective sensitive area parameters of the probe tip for bubble contact events, the distribution information of micron-sized bubbles on the target cross-section is calculated.

[0032] Specifically, the core principle underlying distributed computing is that the number of bubbles passing through the effective sensing area of ​​the probe tip per unit time is proportional to the bubble surface density, the effective sensitive area of ​​the tip, and the flow velocity. Prior to this, an independent calibration process is required to pre-determine the effective sensitive area parameter of each probe (or a representative value from the same batch of probes) for bubble contact events. The effective sensitive area parameter is not simply a geometric area, but an equivalent area that integrates factors such as electrical response characteristics and bubble contact morphology.

[0033] By substituting the flow velocity, the number of voltage drop edges of each probe, the sampling duration, and the calibrated effective sensitive area parameters into the mathematical model established based on the above principle, the distribution information of bubbles on the target cross-section of the pipe can be calculated. The distribution information can be expressed as the bubble surface density in different radial annular regions, or further, the total number of bubbles on the entire cross-section can be obtained, or it can be converted into the average number of bubbles contained in a unit volume of fluid.

[0034] In one possible implementation, the calibration method for the effective sensitive area parameter of the conductivity probe tip for a bubble contact event is as follows: (1) On a calibration pipe with a visible observation section, at least one of the conductivity probes is arranged, the tip of the conductivity probe extending radially into the calibration pipe.

[0035] Specifically, calibration needs to be performed on a calibration pipe with a visible observation section. One section of this calibration pipe is replaced with a viewing window made of high-strength transparent material, with an inner diameter matching that of the metal pipe to be tested. The conductivity probe to be calibrated (a single probe is sufficient, but its model and tip treatment must be consistent with the probes used in subsequent measurements) is installed on this transparent pipe section in the same way as during measurement, with its tip extending into the pipe.

[0036] (2) The calibration fluid containing micron-sized bubbles flows through the calibration pipe, and the following actions are performed simultaneously: The first number of bubbles that actually come into contact at the needle tip is collected using a high-speed imaging system. The second number of voltage drop edges triggered by the bubble contact event is acquired by the electrical signal acquisition system.

[0037] Specifically, prepare a calibration fluid with properties similar to the fluid to be tested, ensuring it contains observable micron-sized bubbles. Flow the calibration fluid at a known and stable rate. It flows through the calibrated pipeline.

[0038] During calibration, two acquisition systems are operated simultaneously: one is a high-speed imaging system, such as a high-speed industrial camera with a microscope lens, which precisely focuses on the probe tip area to directly capture the bubble movement process at a sufficiently high frame rate; the other is an electrical signal acquisition system, which is connected to the conductivity probe to record its voltage output.

[0039] Within a set calibration time Inside, a high-speed camera continuously captures images, and through image processing algorithms, the total number of times the directly observed bubbles come into contact with the probe tip is manually or automatically identified and counted, and recorded as the first count. Simultaneously, the electrical signal acquisition system records the total number of all voltage falling edge pulses output by the probe within the same time period, denoted as the second quantity. For example, image processing algorithms can be background subtraction or edge recognition, which will not be elaborated here.

[0040] (3) Based on the first quantity, the second quantity, and the flow rate of the calibration fluid, determine the effective sensitive area parameter of the needle tip for the bubble contact event, specifically:

[0041] In the formula, The effective sensitive area parameter of the calibrated needle tip for bubble contact events; The first quantity; The second quantity; To calibrate the flow rate of the fluid.

[0042] In theory, if every physical contact could generate an ideal and unmistakably identifiable electrical signal, then Should be with The values ​​are equal. However, due to the small size of microbubbles, potentially insufficient contact, or noise in the electrical signal, there is usually a difference between the two. Based on the physical principle that the bubble flux through the effective sensitive area of ​​the probe tip is equal, a relationship is established to calculate the effective sensitive area value that best matches the observation with the electrical signal. The effective sensitive area value is used as the effective sensitive area parameter for this type of probe for such microbubbles, and is used in the calculation for actual measurements.

[0043] The derivation process of the formula for calculating the effective sensitive area parameter is explained in detail below: The calibration process can correct signal misjudgment caused by small bubble size and insufficient contact, and improve the accuracy of bubble collision recognition. The specific calibration method is as follows: The number of bubbles passing through the effective sensing area of ​​the needle tip per unit time, perpendicular to the calibration fluid direction, is equal to the bubble surface density. Effective sensitive area With flow rate The product of:

[0044] in, The first number is the total number of times the bubble, captured by the imaging system, touches the needle tip within the calibration time. cal This is the duration for synchronous acquisition of imaging and conductivity signals, i.e., the calibration duration. Ideally, the bubble touching the effective area of ​​the needle tip will trigger a conductivity signal at a 1:1 ratio, meaning the actual number of imaging attempts and the number of conductivity signal acquisition attempts satisfy the following:

[0045] in, The second quantity is the total number of voltage fall edges synchronously recorded by the conductivity probe within the calibration time. Combining the above two equations, we can eliminate the bubble density. The calibration formula is obtained as follows:

[0046] The purpose of this calibration is to establish a reliable quantitative relationship between physical contact events of the bubble and electrical signal response events. The formula shows that the effective sensitive area can be calibrated by the ratio of directly observed contact counts to electrical signal counts. It should be noted that in practical applications, to improve calibration accuracy, multiple calibrations are performed, and the average effective sensitive area is taken as the final parameter.

[0047] In one possible implementation, the plurality of conductivity probes are arranged at equal intervals along the circumference of the pipe, and the tips of the plurality of conductivity probes are arranged at equal intervals along the radial direction of the pipe.

[0048] In other words, to sample the pipe cross-section more reasonably and evenly, and to simplify subsequent data processing and distribution reconstruction models, it is preferable to arrange multiple conductivity probes at equal intervals along the circumference of the pipe. In other words, if arranged... N For the root probes, their installation angle interval on the pipe circumference is 360° / N This arrangement helps to avoid measurement deviations caused by uneven circumferential positioning.

[0049] Furthermore, the tips of multiple conductivity probes are arranged at equal intervals along the radial direction of the pipe. For example, when arranging three probes, the tips can be located at radial positions R / 3, 2R / 3, and R, respectively; or at R / 4, R / 2, and 3R / 4. This equal-interval arrangement ensures that the area of ​​the annular region represented by each probe has a regular mathematical relationship (e.g., the area is proportional to the annular number), simplifying the process of calculating the overall cross-sectional distribution.

[0050] In one feasible approach, the specific formula for calculating the total number of micron-sized bubbles contained in a unit volume of fluid across the target cross-section is as follows:

[0051] In the formula, The total number of micron-sized bubbles contained in a unit volume of fluid on the target cross-section; This refers to the number of conductivity probes; The velocity of the fluid to be measured; For the first i The number of voltage falling edges corresponding to the root conductivity probe within a preset sampling time; For the first i The effective sensitive area parameter of the tip of the conductivity probe for bubble contact events; This is the preset sampling duration.

[0052] The derivation of the formula for calculating the total number of micron-sized bubbles per unit volume of fluid on the target cross-section is given in detail below: Start the sampling program and set the sampling duration. Simultaneously, a mass flow meter is used to monitor the flow rate of fluid (water) in the pipeline, combined with the pipeline cross-sectional area. D Calculate the flow velocity of the fluid to be measured. Each conductivity probe captures bubble contact events in real time and records the number of voltage falling edges detected by each probe within the sampling time. Based on the different radial depths of different probes, the pipe cross-section is divided into several annular regions. Combining the effective sensitive area obtained from calibration, the flow velocity of the fluid to be measured, the sampling time, and the pipe cross-sectional area, the bubble density of each region and the overall cross-sectional distribution are calculated according to the following formula.

[0053] Based on the above measurement principle and device characteristics, the following explains the derivation and results of the formula for calculating the number of air bubbles per liter of water in the tube when three probes are arranged: Within a radius of 0 to 1 / 3 R The area of ​​region 1 for:

[0054] At a radius of 1 / 3 R to 2 / 3 of the radius RThe area of ​​region 2 for:

[0055] At 2 / 3 of the radius R to radius The area of ​​region 3 for:

[0056] Let the effective sensitive area of ​​the needle tip be... Then the surface density of the bubbles in regions 1, 2, and 3 is:

[0057]

[0058]

[0059] The total number of bubbles in the area is:

[0060]

[0061]

[0062] The volume of fluid (water) flowing per unit time is as follows:

[0063] The number of bubbles per milliliter of fluid is the ratio of the number of bubbles to the fluid volume:

[0064] in, Distance from the center of the pipe R The number of times the probes positioned at point 6 capture the falling edge of the voltage signal. Distance from the center point of the pipe R The probe positioned at / 2 captures the number of voltage falling edges of the signal. The number of times the falling edge of the voltage signal is captured by a probe positioned 5 / 6R from the center of the tube.

[0065] The fluid velocity inside the pipe is calculated using a mass flow meter. Theoretically, the more probes deployed, the more accurately the bubble density inside the pipe can be determined. When the number of probes is... x When the roots are arranged at equal intervals along the pipe radius, the formula for the distribution of the number of bubbles can be derived as described above: No. i The radius range of the rings is ( i -1)R / N~ i R / N, then the firsti The area of ​​each ring is:

[0066] The area occupied by the ring is 2 i -1.

[0067] The bubble measured by the probe at the first i The bubble surface density of each region is:

[0068] The first can be obtained i The total number of bubbles in each region is:

[0069] N The total number of bubbles in each region is:

[0070] The number of bubbles per milliliter of fluid is calculated as the ratio of the number of bubbles to the fluid volume, as follows:

[0071] The conductivity probe is small in size and has a fast response time, does not affect the flow state inside the pipe, and can achieve transient online measurement. Compared with methods such as the quick-closing valve method that require flow interruption, this invention is suitable for continuous flow scenarios and can capture the dynamic evolution of bubble distribution. Furthermore, by arranging multiple probes at equal intervals along the circumference of the pipe, bubble contact signals at different locations are collected simultaneously. By combining the area weights of each region, the distribution of bubbles on the pipe cross-section can be reconstructed. This method overcomes the dependence of traditional optical imaging methods on pipe transparency and is suitable for real-time measurement of opaque metal pipes.

[0072] This mechanism converts physical contact into countable electrical signal events by detecting the instantaneous voltage signal triggered when a bubble touches the probe tip, thereby quantifying the bubble contact frequency per unit time. Utilizing the detectable physical phenomena generated during the dynamic interaction between the bubble and the probe as a measurement medium, the frequency of micron-sized bubbles is measured. To ensure the reliability of this indirect measurement method, a high-voltage window imaging system is introduced for multi-dimensional calibration: by simultaneously acquiring high-speed photographic images and electrical signal data, a precise correspondence between bubble contact events and voltage drop characteristics is established and determined. Especially in high-density measurement scenarios with densely distributed bubbles, this calibration strategy can effectively reduce the false positive rate of contact events, ultimately achieving a dynamic balance optimization between measurement accuracy and bubble density.

[0073] Combination Figure 2 and Figure 3 The present invention provides a system for measuring the cross-sectional distribution of micron-sized bubbles inside a tube, comprising: The probe array module includes a fixed base 1 and conductive probes 2 mounted on the fixed base 1. The probe array module is used to be installed at the target cross-section of the pipe to be tested, and the tips of multiple conductive probes 2 are inserted into the pipe at different radial depths.

[0074] The signal acquisition and processing module is electrically connected to the probe array module and is used to acquire and process the voltage falling edge signal.

[0075] The flow measurement module is used to acquire the flow rate of the fluid in the pipe under test in real time.

[0076] The data processing module, which is communicatively connected to the signal acquisition and processing module and the flow measurement module, is configured to: calculate the distribution information of micron-sized bubbles on the target cross section based on the flow velocity of the fluid under test, the number of voltage drop edges corresponding to each conductivity probe 2, and the pre-calibrated effective sensitive area parameters of the tip of the conductivity probe 2 for bubble contact events.

[0077] In other words, this system is a hardware platform that integrates mechanical, sensing, data acquisition, and data processing functions. For example... Figure 2 As shown, the core component is the probe array module, which includes a rigid mounting base 1 fixed to the wall of the pipe under test. A conductivity probe 2 is mounted on the mounting base 1. The main body of the conductivity probe 2 passes through a mounting hole on the base, and the tip is configured to extend into the pipe at different radial depths to achieve simultaneous sampling at different radial positions of the cross-section.

[0078] like Figure 3 As shown, the signal acquisition and processing module includes an acquisition unit 3 and a processing unit 4. The input terminal of the acquisition unit 3 is connected to the electrical signal output terminal of each conductivity probe 2 via a shielded cable. The function of the acquisition unit 3 is to acquire the voltage signal of each probe in real time, amplify and filter it to remove noise, and use a waveform recognition algorithm to identify and count the voltage falling edge pulses contained therein, thereby obtaining the number of voltage falling edge signals of each probe.

[0079] Processing unit 4 can be an industrial computer or an embedded processor. It communicates with acquisition unit 3 and flow measurement module via a data interface to receive flow velocity and the number of signals from each probe. Processing unit 4 pre-stores the effective sensitive area of ​​the probe tip, pipe geometric parameters, and calculation programs or formulas obtained from calibration. It is configured to execute calculation logic, automatically calculating distribution information such as bubble surface density distribution, total number of bubbles in the cross-section, and number of bubbles per unit volume based on the received real-time data, and outputs the results on a display or transmits them via a network.

[0080] Preferably, the probe array module further includes a sealing sleeve 5 and a locking component 6. The conductivity probe 2 passes through the fixed base 1 through the sealing sleeve 5, and the locking component 6 adjusts and fixes the radial depth of its tip extending into the pipe to be tested.

[0081] To ensure reliable sealing, electrical insulation, and depth adjustment of the probes under high-pressure fluid conditions, the probe array module also includes a sealing sleeve 5 and a locking component 6. Each conductivity probe 2 has a sealing sleeve 5 fitted over its shank, preferably made of polytetrafluoroethylene (PTFE). The sealing sleeve 5 achieves a static seal with the base through an O-ring structure.

[0082] The locking component 6 is used to adjust and ultimately fix the axial position of the conductivity probe 2. One specific implementation includes: a fine-tuning nut that threads with the probe shaft, and a fixing screw for pressing the probe onto the base. By rotating the fine-tuning nut, the depth to which the probe tip inserts into the pipe can be adjusted. After adjustment, the fixing screw is tightened to prevent displacement under fluid impact. This structure achieves adjustable and fixable radial depth of the probe and ensures a safe seal under high pressure.

[0083] In the description of this invention, it should be understood that the terms "upper", "lower", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0084] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0085] In this invention, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0086] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0087] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0088] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the scope of the technology disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention.

Claims

1. A method for measuring the cross-sectional distribution of micron-sized bubbles inside a tube, characterized in that, include: At the target cross-section of the pipe to be tested, multiple conductivity probes are arranged along the circumference of the pipe, and the tip of each conductivity probe extends into the pipe at a different radial depth. The test fluid containing micron-sized bubbles is passed through the test pipe, the flow velocity of the test fluid is measured, and the voltage falling edge signal output by each conductivity probe within a preset sampling time is collected simultaneously to obtain the number of voltage falling edge signals corresponding to each conductivity probe. Based on the flow velocity of the fluid under test, the number of voltage drop edges corresponding to each conductivity probe, and the pre-calibrated effective sensitive area parameters of the probe tip for bubble contact events, the distribution information of micron-sized bubbles on the target cross-section is calculated.

2. The method for measuring the cross-sectional distribution of micron-sized bubbles inside a tube according to claim 1, characterized in that, The calibration method for the effective sensitive area parameter of the conductivity probe tip in response to a bubble contact event includes: At least one conductivity probe is arranged on the calibration pipe with a visible observation section, the tip of the conductivity probe extending radially into the calibration pipe; The calibration fluid containing micron-sized air bubbles flows through the calibration pipe, and the process is performed synchronously: The first number of bubbles that actually come into contact at the needle tip is collected using a high-speed imaging system. The second number of voltage drop edges triggered by the bubble contact event is acquired by the electrical signal acquisition system. Based on the first quantity, the second quantity, and the flow rate of the calibration fluid, the effective sensitive area parameter of the needle tip for bubble contact events is determined.

3. The method for measuring the cross-sectional distribution of micron-sized bubbles inside a tube according to claim 2, characterized in that, The effective sensitive area parameter of the needle tip for bubble contact events is determined based on the first quantity, the second quantity, and the fluid flow rate, specifically as follows: In the formula, The effective sensitive area parameter of the calibrated needle tip for bubble contact events; The first quantity; The second quantity; To calibrate the flow rate of the fluid.

4. The method for measuring the cross-sectional distribution of micron-sized bubbles inside a tube according to claim 1, characterized in that, The multiple conductivity probes are arranged at equal intervals along the circumference of the pipe, and the tips of the multiple conductivity probes are arranged at equal intervals along the radial direction of the pipe.

5. The method for measuring the cross-sectional distribution of micron-sized bubbles inside a tube according to claim 1, characterized in that, The distribution information of the microbubbles on the target cross-section includes at least: The total number of micron-sized bubbles contained in a unit volume of fluid on the target cross-section.

6. The method for measuring the cross-sectional distribution of micron-sized bubbles inside a tube according to claim 5, characterized in that, The specific formula for calculating the total number of micron-sized bubbles per unit volume of fluid on the target cross-section is as follows: In the formula, The total number of micron-sized bubbles contained in a unit volume of fluid on the target cross-section; This refers to the number of conductivity probes; The velocity of the fluid to be measured; For the first i The number of voltage falling edges corresponding to the root conductivity probe within a preset sampling time; For the first i The effective sensitive area parameter of the tip of the conductivity probe for bubble contact events; This is the preset sampling duration.

7. The method for measuring the cross-sectional distribution of micron-sized bubbles inside a tube according to claim 1, characterized in that, The flow rate of the fluid to be tested is measured by a mass flow meter installed on the pipe to be tested.

8. A system for measuring the cross-sectional distribution of microbubbles inside a tube, used for implementing the method for measuring the cross-sectional distribution of microbubbles inside a tube as described in any one of claims 1-7, characterized in that, include: The probe array module includes a fixed base and conductive probes mounted on the fixed base. The probe array module is used to be installed at the target cross-section of the pipe to be tested, and the tips of multiple conductive probes are inserted into the pipe at different radial depths. The signal acquisition and processing module is electrically connected to the probe array module and is used to acquire and process the voltage falling edge signal; The flow measurement module is used to acquire the flow velocity of the fluid in the pipe under test in real time. The data processing module, which is communicatively connected to the signal acquisition and processing module and the flow measurement module, is configured to: calculate the distribution information of micron-sized bubbles on the target cross-section based on the flow velocity of the fluid under test, the number of voltage drop edges corresponding to each conductivity probe, and the effective sensitive area parameters of the probe tip for bubble contact events pre-calibrated.

9. The tube micron bubble cross-sectional distribution measurement system according to claim 8, characterized in that, The probe array module also includes a sealing sleeve and a locking component. The conductivity probe passes through the sealing sleeve through the fixed base, and the locking component adjusts and fixes the radial depth of its tip extending into the pipe to be tested.

10. The tube micron bubble cross-sectional distribution measurement system according to claim 8, characterized in that, Also includes: The calibration module, used to calibrate a single conductivity probe before performing a measurement, includes a high-voltage window unit, a high-speed imaging unit, and a synchronization control unit, used to acquire the effective sensitive area parameters; The high-pressure viewing window unit is a transparent pipe section with the same diameter as the pipe to be tested, and the high-speed imaging unit focuses on the tip area of ​​the conductivity probe.

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