Electromagnetic Ultrasonic Multiphase Flow Measuring Device and Method Based on Circumferential Ring Loading of Pipeline

Abstract

The present invention provides an electromagnetic ultrasonic multiphase flow measurement device and method based on circumferential annular loading of a pipeline, which relates to the technical field of non-destructive testing. By adopting an electromagnetic ultrasonic excitation method and performing full circumferential loading, full circumferential coverage detection of the pipeline is achieved, the detection of multiphase flow is more accurate, and electromagnetic ultrasound does not require a couplant for energy transfer. Electromagnetic ultrasound can flexibly select the guided wave mode according to the application situation. The guided wave couples into the multiphase flow at the phase interface, which can effectively increase the circumferential detection volume of the fluid in the pipeline and improve the detection accuracy of multiphase flow. At the same time, an electromagnetic ultrasonic transducer with a flexible coil (electromagnetic ultrasonic excitation transducer and electromagnetic ultrasonic receiving transducer) is used, which is small in size and can be used on small-diameter pipes, thus overcoming the various limitations of traditional piezoelectric ultrasound.

Description

Technical Field

[0001] The present invention relates to the technical field of non-destructive testing, and particularly to an electromagnetic ultrasonic multiphase flow measurement device and method based on circumferential annular loading of a pipeline. Background Art

[0002] Pipelines are the main arteries of modern social and economic development. Most of the transportation of oil, natural gas, chemical raw materials, etc. adopts the pipeline method. The multiphase flow phenomenon in pipeline transportation widely exists in modern industrial processes such as bioengineering, oil and gas exploitation, chemical industry, metallurgical industry, and food processing. Accurate detection of its flow process parameters is of great significance for the monitoring, management, analysis, and design of the production process, as well as ensuring the reliable operation of the device and improving production efficiency. In industrial sites and scientific research processes, the most typical multiphase flows are gas / water, oil / water, solid / liquid, and oil / gas / water, etc. The detection means need not cause any disturbance to the fluid to be measured, and the non-contact, simple structure, and penetrability of ultrasonic waves (i.e., ultrasonic waves) have attracted much attention.

[0003] Ultrasonic non-destructive testing is a widely used technology. The propagation of ultrasonic waves will not cause damage to the object to be detected, nor will it cause changes in the flow pattern of the fluid. In the multiphase flow detection of pipelines, ultrasonic detection sensors can be placed on the outer wall of the pipeline to avoid contact with the fluid. Since the propagation speed of ultrasonic waves is different in media with different acoustic impedances, the propagation characteristics of ultrasonic waves in multiphase flow media can be used to obtain the phase medium distribution information on the propagation path, such as the average acoustic impedance or sound velocity of the medium. Especially the huge difference in acoustic impedance at the gas-liquid interface, solid-liquid interface, and solid-gas interface makes the reflection characteristics of ultrasonic waves at the gas-liquid interface, solid-liquid interface, and solid-gas interface extremely obvious. Therefore, ultrasonic waves have excellent resolution ability for the phase interface of multiphase flow. At the same time, ultrasonic waves will be affected by their movement speed in liquid media, resulting in changes in frequency and propagation path. Therefore, ultrasonic waves can accurately measure information such as the flow velocity of liquids.

[0004] Traditional ultrasonic methods for measuring multiphase flow information in pipelines often use ultrasonic phased array methods, that is, multiple ultrasonic phased array probes are arranged on the outer wall of the same cross-section of the pipeline for circumferential measurement. Among them, the ultrasonic phased array probes use piezoelectric ultrasonic probes. The sound waves emitted by the piezoelectric ultrasonic probes are fan-shaped (conical), with a narrow scanning range, large sidelobe attenuation under wide emission angle conditions, and an expanding trend in the bubble projection in the ultrasonic path. Due to the limited number of probes in the ultrasonic array, the detected area inside the pipeline is limited, and it is difficult to achieve full circumferential detection inside the pipeline. Moreover, the piezoelectric ultrasonic probes require the help of a coupling agent to couple energy into the pipeline, which limits their application scenarios in high and low temperature environments and long-term detection. The existing piezoelectric ultrasonic probes are all relatively large in size, and the array-type piezoelectric ultrasonic probes require a relatively large outer diameter of the pipeline to be installed, which also limits the applicable pipeline diameter (hereinafter simply referred to as pipe diameter). Summary of the Invention

[0005] The purpose of the present invention is to provide an electromagnetic ultrasonic multiphase flow measurement device and method based on circumferential annular loading of a pipeline to alleviate at least one problem existing in the ultrasonic phased array method.

[0006] In a first aspect, an embodiment of the present invention provides an electromagnetic ultrasonic multiphase flow measurement device based on circumferential annular loading of a pipeline, including a signal generating device, an electromagnetic ultrasonic excitation transducer using a flexible coil, an electromagnetic ultrasonic receiving transducer using a flexible coil, and a signal processing device connected in sequence; the electromagnetic ultrasonic excitation transducer and the electromagnetic ultrasonic receiving transducer are arranged at different positions of the pipeline to be measured at a preset distance, and are both arranged along the circumferential cross-section of the pipeline to be measured and around the outer wall of the pipeline to be measured;

[0007] The signal generating device is used to generate an excitation electrical signal; the electromagnetic ultrasonic excitation transducer is used to convert the excitation electrical signal into an ultrasonic signal in the pipe wall of the pipeline to be measured; the electromagnetic ultrasonic receiving transducer is used to convert the ultrasonic signal received from inside the pipeline to be measured into a received electrical signal; the signal processing device is used to perform signal processing on the received electrical signal to obtain a multiphase flow detection result corresponding to the pipeline to be measured.

[0008] Further, when the pipeline to be measured is a non-ferromagnetic metal material, both the electromagnetic ultrasonic excitation transducer and the electromagnetic ultrasonic receiving transducer include: a flexible coil and a permanent magnet arranged in a concentric ring shape from the inside to the outside;

[0009] When the pipeline to be measured is a ferromagnetic metal material, both the electromagnetic ultrasonic excitation transducer and the electromagnetic ultrasonic receiving transducer include: a first permanent magnet, a flexible coil, and a second permanent magnet arranged in sequence along the axial direction of the pipeline to be measured, and the first permanent magnet, the flexible coil, and the second permanent magnet are all annular;

[0010] When the pipeline under test is made of non-metallic material, both the electromagnetic ultrasonic excitation transducer and the electromagnetic ultrasonic receiving transducer include: a first permanent magnet, a flexible coil, and a second permanent magnet that are sequentially arranged along the axial direction of the pipeline under test. The first permanent magnet, the flexible coil, and the second permanent magnet are all annular, and a magnetostrictive material is arranged inside the flexible coil.

[0011] Further, both the electromagnetic ultrasonic excitation transducer and the electromagnetic ultrasonic receiving transducer fasten the flexible coil on the pipeline under test through a pneumatic annular electromagnetic ultrasonic transducer clamping device;

[0012] The pneumatic annular electromagnetic ultrasonic transducer clamping device includes an annular airbag. The inner side of the airbag is the flexible coil, and a connecting row buckle is arranged on the outer side of the airbag. The connecting row buckle is used to adapt to different pipeline diameters.

[0013] Further, the signal generating device includes an arbitrary function generator and a high-power pulse signal amplification module that are interconnected;

[0014] The arbitrary function generator is used to generate a basic electrical signal with a certain frequency; the high-power pulse signal amplification module is used to amplify the basic electrical signal into a high-voltage and large-current signal.

[0015] Further, a first impedance matching module is arranged between the signal generating device and the electromagnetic ultrasonic excitation transducer, and a second impedance matching module is arranged between the electromagnetic ultrasonic receiving transducer and the signal processing device.

[0016] Further, a first duplexer is arranged between the signal generating device and the electromagnetic ultrasonic excitation transducer, and the first duplexer is also connected to the signal processing device; a second duplexer is arranged between the electromagnetic ultrasonic receiving transducer and the signal processing device, and the second duplexer is also connected to the signal generating device.

[0017] Further, the signal processing device includes a power limiting module, a programmable gain amplification module, a variable filter, and an ADC digital acquisition system that are connected in sequence;

[0018] The signal processing device is used to sequentially perform power limiting, amplification, filtering, and analog-to-digital conversion on the received electrical signal through the power limiting module, the programmable gain amplification module, the variable filter, and the ADC digital acquisition system to obtain a digital detection signal, and determine the multiphase flow detection result corresponding to the pipeline under test based on the digital detection signal.

[0019] Second aspect, an embodiment of the present invention further provides an electromagnetic ultrasonic multiphase flow measurement method based on circumferential annular loading of a pipeline, which is applied to the electromagnetic ultrasonic multiphase flow measurement device based on circumferential annular loading of the pipeline in the first aspect; the electromagnetic ultrasonic multiphase flow measurement method based on circumferential annular loading of the pipeline includes:

[0020] Obtain the received electrical signal and echo time output by the electromagnetic ultrasonic receiving transducer; wherein, the echo time is the propagation duration of the ultrasonic signal received by the electromagnetic ultrasonic receiving transducer;

[0021] Determine the ultrasonic attenuation coefficient according to the received electrical signal, and determine the phase fraction corresponding to the pipeline under test according to the ultrasonic attenuation coefficient;

[0022] Calculate the flow velocity corresponding to the pipeline under test according to the echo time.

[0023] Further, when the flow pattern of the multiphase flow corresponding to the pipeline under test is stratified flow, the electromagnetic ultrasonic multiphase flow measurement method based on circumferential annular loading of the pipeline further includes:

[0024] Calculate the liquid level height of the interface in the pipeline under test according to the echo time.

[0025] Further, before obtaining the received electrical signal and echo time output by the electromagnetic ultrasonic receiving transducer, the electromagnetic ultrasonic multiphase flow measurement method based on circumferential annular loading of the pipeline further includes:

[0026] Obtain the characteristic parameters of the pipeline under test, where the characteristic parameters include material properties, inner radius, and outer radius;

[0027] Determine the wire spacing of the flexible coil and the frequency of the excitation electrical signal according to the characteristic parameters;

[0028] Fabricate the electromagnetic ultrasonic excitation transducer and the electromagnetic ultrasonic receiving transducer according to the wire spacing of the flexible coil;

[0029] Determine the operating frequency of the signal generating device according to the frequency of the excitation electrical signal.

[0030] The electromagnetic ultrasonic multiphase flow measurement device and method based on circumferential annular loading of a pipeline provided by an embodiment of the present invention adopt an electromagnetic ultrasonic excitation method and perform full circumferential loading, achieving full circumferential coverage detection of the pipeline, making the detection of multiphase flow more accurate. Moreover, electromagnetic ultrasound does not require a coupling agent for energy transfer, and electromagnetic ultrasound can easily excite the guided wave mode, which can be coupled into the multiphase flow through mode selection (that is, electromagnetic ultrasound can flexibly select the guided wave mode according to the application situation, and the guided wave is coupled into the multiphase flow at the phase interface), effectively increasing the circumferential detection volume of the fluid in the pipeline and improving the detection accuracy of multiphase flow. At the same time, an electromagnetic ultrasonic transducer with a flexible coil (electromagnetic ultrasonic excitation transducer and electromagnetic ultrasonic receiving transducer) is used, which has a small volume and can be used on small-diameter pipes, thus overcoming the various limitations of traditional piezoelectric ultrasound. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 Schematic diagram of ultrasonic energy coupling from a solid into a multiphase flow medium;

[0033] Figure 2 Schematic diagram of the ultrasonic path of piezoelectric ultrasound in a dispersed flow;

[0034] Figure 3 Schematic diagram of the full circumferential electromagnetic ultrasonic loading and propagation path of the pipeline provided by an embodiment of the present invention;

[0035] Figure 4 Schematic diagram of the structure of an electromagnetic ultrasonic multiphase flow measurement device based on circumferential annular loading of a pipeline provided by an embodiment of the present invention;

[0036] Figure 5 Schematic diagram of the forward and reverse transmission of ultrasound;

[0037] Figure 6a Circumferential cross-sectional view of an electromagnetic ultrasonic transducer corresponding to a non-ferromagnetic metal material provided by an embodiment of the present invention;

[0038] Figure 6b Axial cross-sectional view of an electromagnetic ultrasonic transducer corresponding to a ferromagnetic metal material provided by an embodiment of the present invention;

[0039] Figure 6c Appearance schematic diagram of an electromagnetic ultrasonic transducer corresponding to a ferromagnetic metal material provided by an embodiment of the present invention;

[0040] Figure 6d It is an axial sectional view of an electromagnetic ultrasonic transducer corresponding to a non-metallic material provided by an embodiment of the present invention;

[0041] Figure 7a It is a schematic structural diagram of a pneumatic annular electromagnetic ultrasonic transducer clamping device provided by an embodiment of the present invention;

[0042] Figure 7b It is a developed view of a connecting snap fastener in a pneumatic annular electromagnetic ultrasonic transducer clamping device provided by an embodiment of the present invention;

[0043] Figure 8 It is a schematic flow diagram of an electromagnetic ultrasonic multiphase flow measurement method based on circumferential annular loading of a pipeline provided by an embodiment of the present invention;

[0044] Figure 9 It is a schematic diagram of different wave modes of ultrasonic guided waves in a pipeline;

[0045] Figure 10a It is a dispersion curve graph of ultrasonic guided waves in a pipeline;

[0046] Figure 10b It is a schematic diagram of the wave structure at the 348 kHz frequency point;

[0047] Figure 11 It is a flexible coil and its ultrasonic excitation signal diagram;

[0048] Figure 12 It is a schematic diagram of different flow patterns;

[0049] Figure 13 It is a schematic diagram of the ultrasonic propagation path and measurement of stratified flow;

[0050] Figure 14 It is a schematic diagram of the ultrasonic propagation path of a pipeline in the downstream direction;

[0051] Figure 15 It is a schematic diagram of the relationship between ultrasonic attenuation and phase fraction of dispersed flow.

[0052] Icons: 101 - Arbitrary function generator; 102 - High-power pulse signal amplification module; 103 - First duplexer; 104 - First impedance matching module; 105 - Electromagnetic ultrasonic excitation transducer; 106 - Electromagnetic ultrasonic receiving transducer; 107 - Second impedance matching module; 108 - Second duplexer; 109 - Power limiting module; 110 - Programmable gain amplification module; 111 - Variable filter; 112 - ADC digital acquisition system; 201 - Pipe wall; 202 - Flexible coil; 203 - Permanent magnet; 2031 - North pole of permanent magnet; 2032 - South pole of permanent magnet; 204 - Magnetostrictive material; 301 - Airbag; 302 - Connecting snap fastener; 303 - Inflation and deflation hole; 304 - Connecting wire socket. Detailed implementation

[0053] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0054] Electromagnetic ultrasound is a method of generating ultrasound inside the measured material using electromagnetic effects. Although the efficiency is reduced compared to piezoelectric ultrasound, it does not require a coupling agent for energy transfer. At the same time, the electromagnetic ultrasound transducer using a flexible coil has a smaller volume and can be used on small-diameter pipes, thus overcoming various limitations of traditional piezoelectric ultrasound. Electromagnetic ultrasound can perform 360° ultrasonic excitation in the circumferential direction of the pipe to achieve full-circumference ultrasonic transmission and full coverage of the ultrasound inside the pipe, making the detection of multiphase flow more accurate. At the same time, traditional ultrasonic detection mostly uses the bulk wave mode of pulses, while electromagnetic ultrasound can easily excite the guided wave mode, which can be coupled into the multiphase flow through mode selection, effectively increasing the circumferential detection volume of the fluid inside the pipe and improving the detection accuracy of multiphase flow. Among them, the bulk wave is a wave propagating in an infinite homogeneous medium; the guided wave is formed by multiple reciprocating reflections between discontinuous interfaces in the medium and further generates complex interference and geometric dispersion, and is an elastic wave propagating parallel to the boundary in the waveguide at ultrasonic frequency or acoustic frequency.

[0055] Based on this, an electromagnetic ultrasonic multiphase flow measurement device and method based on circumferential annular loading of a pipe provided by an embodiment of the present invention, aiming at the problems that the current piezoelectric ultrasonic probe requires a coupling agent and has a large volume, adopts an electromagnetic ultrasonic excitation method and realizes full-circumference loading to achieve full-coverage detection of the pipe circumference; uses the ultrasonic guided wave mode to replace the pulsed body wave for multiphase flow detection to improve the detection accuracy; uses a modular design scheme to simplify the complexity of the array system and facilitate the expansion and maintenance of the system.

[0056] Embodiments of the present invention mainly rely on electromagnetic ultrasound to measure parameters such as flow velocity, phase fraction, and phase interface in multiphase flow in pipelines. The basic principle is as follows:

[0057] According to the basic theory of the vibration of ultrasonic guided waves in solids and the energy propagation of coupled vibrations with surface fluids, it can be obtained that ultrasonic energy is coupled from the guided wave surface into the fluid at a fixed angle θ, and thus effectively converted into a compression wave in the fluid, as Figure 1 shown.

[0058]

[0059] In the formula, c f is the sound velocity of the compression wave in the liquid, and c p is the phase velocity of ultrasound in the pipe wall.

[0060] In a liquid, sound waves can only be transmitted as longitudinal waves, and the sound velocity formula is:

[0061]

[0062] In the formula, k is the bulk modulus and ρ is the medium density.

[0063] There are very large differences in the sound velocities in solids, liquids, and gases. Therefore, the thickness of the phase in the transmission path can be calculated based on the transit time of ultrasound in different phases. At the same time, according to the reflection law and transmission law (In the formula, the acoustic impedance (In the formula, ρ is the medium density and E is the material stiffness), and W1 and W2 are the acoustic impedances of medium 1 and medium 2 respectively), the interface distribution problem between different phases can be obtained. At the same time, different flow velocities of the fluid will cause changes in the ultrasonic path coupled from the pipe wall into the fluid, so that the time received by the ultrasound changes with the flow velocity of the fluid.

[0064] For the case of dispersed flow or when the acoustic impedances of the phase media are relatively close, the measurement method of ultrasonic attenuation is often used to measure the phase fraction in multiphase flow. The difference in the signal intensities between the ultrasonic transmitting end and the receiving end is caused by the attenuation mechanism of ultrasonic propagation in the fluid. Therefore, the ultrasonic attenuation coefficient α is defined as:

[0065]

[0066] Wherein, P2 is the average pressure emitted by the ultrasonic transmitting end, and P1 is the average pressure received by the ultrasonic receiving end. The principle of ultrasonic measurement of multiphase flow solution is based on hydrodynamic and thermodynamic effects. During the attenuation process of ultrasonic waves, there are various attenuation mechanisms, such as scattering loss, thermal loss, viscous loss, absorption loss, structural loss, and electroacoustic loss, etc. Therefore, when using the ultrasonic attenuation method to measure the phase fraction in multiphase flow, a method of fitting the attenuation coefficient in a specific phase fraction range is generally adopted. For example, in an oil-water two-phase dispersed flow, the total attenuation α of ultrasonic wave energy TOL mainly includes: the medium absorption attenuation α of the two-phase fluid T , the scattering attenuation α of the two-phase interface formed by multiple discrete phase droplets R , and the diffusion attenuation α caused by the ultrasonic beam pointing angle and complex propagation path D , as Figure 2 shown.

[0067] α TOL =α T +α R +α D

[0068] In the oil-water two-phase dispersed flow, the absorption attenuation degree of ultrasonic waves and the oil content are typically a first-order linear relationship. As the oil content increases, the viscous attenuation degree increases linearly. Therefore, within a certain range, the oil content can be determined according to the ultrasonic attenuation coefficient value.

[0069] In Figure 3 shows the ultrasonic loading situation of the full circumferential electromagnetic ultrasonic. Its ultrasonic propagation path is different from the circumferential cross-section propagation of piezoelectric ultrasonic, and it mainly propagates in the axial cross-section. Since the full circumferential ultrasonic source no longer has the problem of the detection area caused by the ultrasonic beam pointing angle in the same oil-water two-phase dispersed flow, the detection area for multiphase flow is larger, increasing the coverage volume of the ultrasonic attenuation measurement method and improving the measurement accuracy.

[0070] Next, a detailed introduction will be given to an electromagnetic ultrasonic multiphase flow measurement device based on circumferential annular loading of a pipeline provided by an embodiment of the present invention.

[0071] As Figure 4 shown, the electromagnetic ultrasonic multiphase flow measurement device based on circumferential annular loading of a pipeline includes a signal generating device, an electromagnetic ultrasonic excitation transducer 105 using a flexible coil, an electromagnetic ultrasonic receiving transducer 106 using a flexible coil, and a signal processing device connected in sequence; the electromagnetic ultrasonic excitation transducer 105 and the electromagnetic ultrasonic receiving transducer 106 are arranged at different positions on the pipeline to be measured at a preset distance, and are both arranged along the circumferential cross-section of the pipeline to be measured and surround the outer wall of the pipeline to be measured;

[0072] The signal generating device is used to generate an excitation electrical signal; the electromagnetic ultrasonic excitation transducer 105 is used to convert the excitation electrical signal into an ultrasonic signal in the pipe wall to be measured; the electromagnetic ultrasonic receiving transducer 106 is used to convert the ultrasonic signal received from the inside of the pipe to be measured into a received electrical signal; the signal processing device is used to perform signal processing on the received electrical signal to obtain the multiphase flow detection result corresponding to the pipe to be measured. Among them, both the excitation electrical signal and the received electrical signal can be voltage signals.

[0073] The electromagnetic ultrasonic transducer (the electromagnetic ultrasonic excitation transducer 105 and the electromagnetic ultrasonic receiving transducer 106) can cause the vibration of the pipe wall particles by the excitation electrical signal to generate ultrasonic waves. At the same time, due to the vibration of the pipe wall particles, the magnetic field can be cut to generate an induced voltage on the flexible coil to receive the ultrasonic signal.

[0074] Optionally, as Figure 4 shown, the above signal generating device includes an arbitrary function generator 101 and a high-power pulse signal amplification module 102 connected to each other; the arbitrary function generator 101 is used to generate a basic electrical signal with a certain frequency; the high-power pulse signal amplification module 102 is used to amplify the basic electrical signal into a high-voltage and high-current signal.

[0075] Specifically, the arbitrary function generator 101 is mainly responsible for generating a signal with a certain frequency (which can generate any modulated signal type), and this signal is amplified into a high-voltage and high-current signal by the high-power pulse signal amplification module 102 to drive the electromagnetic ultrasonic excitation transducer 105.

[0076] Further optionally, as Figure 4 shown, the above signal processing device includes a power limiting module 109, a programmable gain amplification module 110, a variable filter 111, and an ADC digital acquisition system 112 connected in sequence; the signal processing device is used to perform power limiting, amplification, filtering, and analog-to-digital conversion on the received electrical signal in sequence through the power limiting module 109, the programmable gain amplification module 110, the variable filter 111, and the ADC digital acquisition system 112 to obtain a digital detection signal, and based on the digital detection signal, determine the multiphase flow detection result corresponding to the pipe to be measured.

[0077] Specifically, for the received electrical signal output by the electromagnetic ultrasonic receiving transducer 106, the power limiting module 109 is required to avoid damage to the subsequent conditioning circuit due to receiving an excessive signal. The programmable gain amplification module 110, the variable filter 111, and the ADC digital acquisition system 112 are respectively responsible for amplifying, filtering, and performing analog-to-digital conversion on the received signal to facilitate the subsequent signal processing and the calculation of different parameters of the multiphase flow.

[0078] Further optionally, as Figure 4As shown in the figure, a first duplexer 103 and a first impedance matching module 104 are sequentially arranged between the high-power pulse signal amplification module 102 and the electromagnetic ultrasonic excitation transducer 105. The first duplexer 103 is also connected to the power limiting module 109; a second impedance matching module 107 and a second duplexer 108 are sequentially arranged between the electromagnetic ultrasonic receiving transducer 106 and the power limiting module 109. The second duplexer 108 is also connected to the high-power pulse signal amplification module 102.

[0079] Specifically, the high-power pulse signal amplification module 102 includes two channels, and the two channels are respectively connected to the first duplexer 103 and the second duplexer 108. The duplexer (including the first duplexer 103 and the second duplexer 108) is a two-way working device that can not only allow signals to enter the electromagnetic ultrasonic transducer, but also feedback the signals received in the electromagnetic ultrasonic transducer back into the signal processing device. It is a three-port device. Since the flexible coil of the electromagnetic ultrasonic transducer is a non-pure resistive device, in order to ensure that the high-voltage and large-current signals output by the high-power pulse signal amplification module 102 can enter the electromagnetic ultrasonic excitation transducer 105 with high efficiency, the impedance matching module (including the first impedance matching module 104 and the second impedance matching module 107) can transform the impedance of the electromagnetic ultrasonic transducer to a pure resistive state to improve the signal output efficiency.

[0080] The above-mentioned arbitrary function generator 101 generates the required excitation small signal, and this small signal is amplified by the high-power pulse signal amplification module 102 into a high-voltage and large-current signal with a peak-to-peak current of more than 30A. This signal enters the flexible coil of the electromagnetic ultrasonic excitation transducer 105 through the first duplexer 103 and the first impedance matching module 104, generating ultrasonic waves inside the pipe wall. The ultrasonic waves in the pipe wall propagate along the Figure 1 path shown. It should be noted that Figure 1 the path shown only shows the two-dimensional path as a cross-section. In actual three-dimensional pipes, Figure 1 the path shown is transmitted circumferentially along the axial direction in the pipe wall. At the same time, the electromagnetic ultrasonic excitation transducer and the electromagnetic ultrasonic receiving transducer can be functionally interchanged during the measurement process to achieve symmetric loading of ultrasonic waves and realize forward and reverse propagation on the ultrasonic transmission path, as shown in Figure 5 .

[0081] The generation method of ultrasonic waves needs to be processed differently according to the material of the pipe wall, which can be divided into two cases:

[0082] 1) When the pipe wall material is a metal material, the electromagnetic ultrasonic transducer can be composed of a static bias magnetic field generating device and a coil; the principle of the electromagnetic ultrasonic transducer causing ultrasonic vibration can be divided into two categories: Lorentz force and magnetostrictive force. Among them, the Lorentz force is applicable to all metal pipes, and the magnetostrictive force is only applicable to magnetic metal pipes.

[0083] 2) When the pipe wall material is non-metallic, the electromagnetic ultrasonic transducer cannot directly generate ultrasonic waves in the pipe wall. It is necessary to use magnetostrictive materials to fasten the sheet-shaped material around the pipe wall. Ultrasonic waves are generated in the magnetostrictive material and propagated into the non-metallic pipe. That is, surface-fastening high-performance magnetostrictive sheets can also be used to achieve ultrasonic excitation and reception in non-metallic pipes.

[0084] In this way, electromagnetic ultrasound is no longer limited to the application in metal pipes, and multi-phase flow measurement of pipe walls made of common materials can be realized. Based on this, the structure of the electromagnetic ultrasonic transducer can be as follows:

[0085] When the measured pipe is made of non-ferromagnetic metal material, the electromagnetic ultrasonic excitation principle is the Lorentz force. As Figure 6a shown, the electromagnetic ultrasonic transducer includes: a flexible coil 202 and a permanent magnet arranged in a concentric ring shape from the inside to the outside. The permanent magnet includes a permanent magnet N pole 2031 and a permanent magnet S pole 2032. Specifically, the flexible coil 202 is arranged around the pipe wall 201, and the permanent magnet N pole 2031 and the permanent magnet S pole 2032 are sequentially arranged outside the flexible coil 202.

[0086] When the measured pipe is made of ferromagnetic metal material, the electromagnetic ultrasonic excitation principle is magnetostriction and the Lorentz force. As Figure 6b and Figure 6c shown, the electromagnetic ultrasonic transducer includes: permanent magnets 203, a flexible coil 202, and permanent magnets 203 arranged in sequence along the axial direction of the measured pipe. The two permanent magnets 203 and the flexible coil 202 are all annular.

[0087] When the measured pipe is made of non-metallic material, as Figure 6d shown, the electromagnetic ultrasonic transducer includes: permanent magnets 203, a flexible coil 202, and permanent magnets 203 arranged in sequence along the axial direction of the measured pipe. The two permanent magnets 203 and the flexible coil 202 are all annular, and a magnetostrictive material 204 is arranged inside the flexible coil 202. The magnetostrictive material 204 can be in the shape of a thin sheet. When fixing the electromagnetic ultrasonic transducer on the pipe, the magnetostrictive material 204 can be fixed on the outer wall of the pipe first, and then the flexible coil 202 can be fixed.

[0088] It should be noted that Figure 6d the structure of the electromagnetic ultrasonic transducer shown is similar to the structure of the electromagnetic ultrasonic transducer shown in Figure 6b The only difference is whether there is a magnetostrictive material 204 inside the flexible coil 202. Therefore, the appearances of the electromagnetic ultrasonic transducers with the two structures can be the same.

[0089] For the purpose of realizing the long-term stable measurement of pipeline multiphase flow and being modular and easy to install, this embodiment also provides a pneumatic annular electromagnetic ultrasonic transducer clamping device, which fastens the flexible coil of the electromagnetic ultrasonic transducer on the pipeline to be measured through the pneumatic annular electromagnetic ultrasonic transducer clamping device. As Figure 7a shown, the pneumatic annular electromagnetic ultrasonic transducer clamping device includes an annular airbag 301. The inner side of the airbag 301 is the flexible coil 202 of the electromagnetic ultrasonic transducer. A connecting buckle 302 is arranged on the outer side of the airbag 301, and the connecting buckle 302 is used to adapt to different pipeline diameters. As Figure 7b shown, the connecting buckle 302 can include multiple rows of tightening buckles. In addition, as Figure 7a shown, an air charging and discharging hole 303 and a connecting wire socket 304 are also arranged on the outer side of the airbag 301.

[0090] The pneumatic annular electromagnetic ultrasonic transducer clamping device is responsible for conveniently fastening the electromagnetic ultrasonic transducer outside the pipeline walls with different diameters. The periphery of the pneumatic annular electromagnetic ultrasonic transducer clamping device has locking buckles with a certain spacing, and different locking buckles can be selected according to different pipe diameters to achieve pre-fastening. The middle of the pneumatic annular electromagnetic ultrasonic transducer clamping device is made of inflatable soft sealing material, and the inner side is the flexible coil 202 of the electromagnetic ultrasonic transducer. The flexible coil 202 is tightly attached to and detached from the pipe wall by inflating and deflating. The pneumatic annular electromagnetic ultrasonic transducer clamping device realizes the modularization of the electromagnetic ultrasonic transducer, making the electromagnetic ultrasonic multiphase flow measurement device based on circumferential annular loading of the pipeline more convenient and improving the installation efficiency.

[0091] The electromagnetic ultrasonic multiphase flow measurement device based on circumferential annular loading of the pipeline provided by the embodiment of the present invention mainly has the following advantages: (1) By adopting the pneumatic annular electromagnetic ultrasonic transducer clamping device, the installation of the electromagnetic ultrasonic transducer is more convenient, and the installation efficiency is improved. (2) Compared with the common piezoelectric ultrasonic detection systems on the market, it does not require a coupling agent, can be used in a more severe detection environment, is easy to install, and can realize long-term on-line monitoring. (3) It realizes 360° ultrasonic excitation of the entire circumference of the pipeline. Compared with the piezoelectric ultrasonic array, the error is smaller and the obtained information is more accurate. (4) In the form of electromagnetic ultrasonic pipeline guided wave excitation and coupling into the multiphase flow medium, the multiphase flow information in a slightly bent pipeline can be measured.

[0092] Next, a detailed introduction to the electromagnetic ultrasonic multiphase flow measurement method based on circumferential annular loading of the pipeline provided by the embodiment of the present invention will be given.

[0093] Refer to Figure 8 the flow schematic diagram of an electromagnetic ultrasonic multiphase flow measurement method based on circumferential annular loading of the pipeline shown. This method mainly includes the following steps:

[0094] Step S802: Obtain the received electrical signal output by the electromagnetic ultrasonic receiving transducer and the echo time; wherein, the echo time is the propagation duration of the ultrasonic signal received by the electromagnetic ultrasonic receiving transducer.

[0095] The above echo time is equal to the time difference between the time when the electromagnetic ultrasonic exciting transducer emits ultrasonic waves and the time when the electromagnetic ultrasonic receiving transducer receives the ultrasonic signal.

[0096] Step S804: Determine the ultrasonic attenuation coefficient according to the received electrical signal, and determine the phase holdup corresponding to the pipeline to be measured according to the ultrasonic attenuation coefficient.

[0097] The calculation formula of the ultrasonic attenuation coefficient can be as follows:

[0098]

[0099] Wherein, P1 and P2 are respectively the average pressure received by the electromagnetic ultrasonic receiving transducer and the average pressure emitted by the electromagnetic ultrasonic exciting transducer, and the average pressure is directly proportional to the voltage amplitude of the corresponding electromagnetic ultrasonic transducer.

[0100] There is a certain corresponding relationship between the ultrasonic attenuation coefficient and the phase holdup. The phase holdup corresponding to the pipeline to be measured can be determined based on the corresponding relationship curve between the ultrasonic attenuation coefficient and the phase holdup obtained by fitting under the same pipe diameter and the frequency of the exciting electrical signal.

[0101] Step S806: Calculate the flow velocity corresponding to the pipeline to be measured according to the echo time.

[0102] Further, when the flow pattern of the multiphase flow corresponding to the pipeline to be measured is stratified flow, the above method further includes: calculating the liquid level height of the interface in the pipeline to be measured according to the echo time.

[0103] In addition, for the gas-liquid interface, the liquid level height of the interface can be calculated first according to the echo time, and then the gas-liquid holdup can be estimated according to the liquid level height and the inner diameter of the pipeline to be measured.

[0104] Further, before measurement, the above method further includes: obtaining the characteristic parameters of the pipeline to be measured, where the characteristic parameters include material properties, inner radius and outer radius; determining the wire spacing of the flexible coil and the frequency of the exciting electrical signal according to the characteristic parameters; manufacturing the electromagnetic ultrasonic exciting transducer and the electromagnetic ultrasonic receiving transducer according to the wire spacing of the flexible coil; determining the working frequency of the signal generating device according to the frequency of the exciting electrical signal.

[0105] In a possible implementation manner, the above method is implemented through the following process:

[0106] 1. First, according to the material properties, inner and outer radii and other parameters of the pipeline to be detected, use commercial software to calculate the dispersion curve of the corresponding free hollow cylindrical structure of the pipeline to be detected and the wave structure at each frequency point under different wave modes. The electromagnetic ultrasonic excitation transducer is circumferentially loaded, so only L(0,1), L(0,2), L(0,3)···, T(0,1), T(0,2), T(0,3)··· and F(0,1), F(0,2), F(0,3)··· in the ultrasonic modes will appear. Since the L(0,1) mode is radially symmetric vibration, while the L(0,2) mode has asymmetric radial motion and differential vibration of the pipe wall, as Figure 9 shown, the wave structures of the F mode and T mode are relatively complex, which is not conducive to the later processing of ultrasonic signals, so they are not considered. By analyzing the wave structure of the L(0,1) mode, it can be seen that the vibration components of the ultrasonic wave only have displacement components in the radial and axial directions. Such a wave structure is simple and the signal processing difficulty is low. Therefore, the L(0,1) mode is selected. At the same time, only the radial displacement in the L(0,1) mode contributes to the generation of ultrasonic waves in the pipe fluid. Therefore, select the frequency point with a larger radial displacement in the L(0,1) mode (it needs to be selected within the range allowed by the actual use environment and coil spacing). The wave structure diagram of the 348 kHz frequency point is as Figure 10a and Figure 10b shown (in the calculation of the dispersion curve, the pipeline is made of aluminum alloy 6061 material, with an outer diameter of 100 mm and a wall thickness of 2 mm). According to the determined frequency point, the corresponding phase velocity can be calculated, and the ultrasonic wavelength can be calculated by dividing the phase velocity by the frequency. In the electromagnetic ultrasonic excitation transducer, a folded coil is used, so the coil pitch (3 mm) is half of the wavelength. The frequency of the excitation electrical signal in the coil is the determined frequency point of 348 kHz.

[0107] 2. After the wave mode is selected, it is necessary to complete the design of the flexible coil according to the mode. The pneumatic annular electromagnetic ultrasonic transducer clamping device designed with a flexible coil can well complete the ultrasonic excitation of the entire circumference of the pipeline. Measure the impedance characteristics of the coil and the output impedance information of the high-power pulse signal amplification module, and make an impedance matching module. At the same time, select the excitation electrical signal with an appropriate frequency according to the determined wave mode, generate it by an arbitrary function generator, and use the Gaussian function to modulate the sine wave to make its frequency components more single. The folded flexible coil can reduce the energy of other modes through constructive interference and increase the signal-to-noise ratio of the detection system. The flexible coil and its ultrasonic excitation signal are as Figure 11 shown.

[0108] 3. Use the obtained electromagnetic ultrasonic multiphase flow measurement device based on circumferential annular loading of the pipeline for detection.

[0109] 4. In the detection of multiphase flow, it can be mainly divided into two cases according to the flow pattern of multiphase flow, such asFigure 12 As shown in:

[0110] 1) Stratified flow. The ultrasonic reflectivity of the phase interface between different phase media in the pipeline is different. Therefore, different measurement methods need to be formulated according to the measured medium during the actual measurement process.

[0111] For example, in the oil-gas-water three-phase flow (as shown in Figure 13 (a)), at the oil-water interface, most of the ultrasonic energy can penetrate the oil bubbles or oil layers, but there are changes in the ultrasonic amplitude for the oil-water two-phase with different volume fractions. Based on this characteristic, the ultrasonic attenuation coefficient can be used to estimate the oil-water volume fraction. At the same time, a small part of the energy will be reflected back at the oil-water interface and transmitted to the pipe wall. Therefore, the liquid level height and flow rate of the water layer can be calculated accordingly.

[0112] For the gas-liquid interface (as shown in Figure 13 (b)), due to the almost total reflection phenomenon at the gas-liquid interface, but due to the obvious difference in the sound speed caused by different gas layer heights, it has good time resolution. Based on this characteristic, the gas-liquid volume fraction can be estimated according to the echo time. The instantaneous liquid level height of the gas-liquid interface can be expressed as:

[0113]

[0114] In the formula, c f is the ultrasonic sound speed in the liquid phase (in the actual measurement process, the measured medium is known, so c f is known), and ΔT is the transit time (i.e., the echo time). At the same time, the propagation angle of the ultrasonic wave in the fluid is fixed, and it propagates along both the downstream and upstream sides simultaneously, and then is reflected to reach the pipe wall and generate ultrasonic guided waves in the pipe wall. The guided wave has a mode with a large perpendicular displacement to the wall surface that is easy to couple energy into the fluid and a mode with a large parallel displacement to the wall surface that is not easy to couple into the fluid. Since the energy of the mode with a large perpendicular displacement to the wall surface will decrease rapidly during propagation in the pipe wall, in the selection of the ultrasonic echo detection signal, the mode with a small parallel displacement and small energy attenuation is preferably selected. As shown in Figure 14 , it can be seen that the ultrasonic echo signal of the downstream path is received by the electromagnetic ultrasonic receiving transducer, and its echo time is related to the spatial distance between the two electromagnetic ultrasonic transducers, the flow rate of the fluid, and the angle θ. In addition, the ultrasonic echo signal of the upstream path is received by the electromagnetic ultrasonic exciting transducer, and its echo time is mainly related to the flow rate of the fluid and the angle θ. Therefore, the flow rate of the corresponding fluid can be calculated through the echo time.

[0115] The following takes the downstream path as an example to introduce the flow rate measurement principle:

[0116] The time (i.e., the echo time) when the electromagnetic ultrasonic receiving transducer receives the ultrasonic signal of the propagation path propagating into the liquid is:

[0117]

[0118] In the formula, D is the inner diameter of the pipeline, L is the distance between the electromagnetic ultrasonic excitation transducer and the electromagnetic ultrasonic receiving transducer, and c g is the group velocity of the ultrasonic signal propagating in the pipeline wall. Among them, X′ is:

[0119]

[0120] In the formula, v is the flow velocity of the measured liquid.

[0121] According to the above formulas (1) and (2), the flow velocity of the measured liquid can be calculated.

[0122] 2) Dispersed flow mainly appears under the condition of relatively large flow velocity. Typical dispersed flows are gas-liquid two-phase dispersed flow or oil-water two-phase dispersed flow, etc. The ultrasonic guided wave energy in the pipeline couples into the fluid, and the energy of the ultrasonic receiving end is greatly attenuated due to the attenuation of ultrasonic waves in the fluid such as absorption, scattering, and diffraction. The condition for ultrasonic wave propagation requires a propagation medium. The medium molecules will generate vibration phenomena during the propagation of sound waves, resulting in the conversion of part of the ultrasonic wave energy into heat. This is the absorption phenomenon of ultrasonic waves during the propagation process in the medium. When ultrasonic waves propagate in a non-uniform mixed medium, due to the acoustic impedance difference between different media, ultrasonic waves will scatter when passing through the interface of different media, resulting in the attenuation of the ultrasonic wave energy that should have propagated in the propagation direction. Due to the relationship between the ultrasonic wavelength and the bubble size of the dispersed phase in the gas-liquid two-phase flow, the occurrence of ultrasonic diffraction phenomenon may be caused. In the measurement of dispersed flow using ultrasonic attenuation, researchers have given the influencing factors of the sound pressure amplitude attenuation:

[0123]

[0124] In the formula, A0 is the initial sound pressure amplitude at the ultrasonic wave emission place, A is the sound pressure amplitude of the ultrasonic wave at the propagation distance L, Γ is the volume interface area, α is the scattering coefficient, and d sm is the Sauter mean diameter, and k is the wave number of the ultrasonic wave.

[0125] According to the above theory and the information such as the pipe diameter and excitation frequency in the experiment, it is necessary to fit the information such as the phase fraction in the dispersed flow by intervals and cases, and it is calculated from the ultrasonic amplitude measured by the electromagnetic ultrasonic transducer. For example, in the actual measurement process, since the particle size and position of the discrete phase in the oil-water two-phase flow have an important impact on the ultrasonic attenuation characteristics, and the droplet size distributions in different oil content ranges and different flow patterns in the actual flow are all different. Such as Figure 15As shown, when other conditions are determined, the ultrasonic attenuation of different oil contents is also relatively complex. Therefore, experiments on prior data and parameter fitting are particularly important in measurement. At the same time, full circumferential ultrasonic coupling provides richer multiphase flow information compared to forms such as piezoelectric arrays and is more accurate in data inversion and calculation.

[0126] Regarding the flow velocity problem of dispersed flow, it can be analyzed according to the calculation method of flow velocity in stratified flow. Due to the loading method of full circumferential electromagnetic ultrasonic, the transit volume of ultrasonic in dispersed flow is larger, and it has stronger robustness to disturbances such as bubbles or oil bubbles, and the overall flow velocity can be measured in dispersed flow.

[0127] 5. The signals received by the electromagnetic ultrasonic receiving transducer and the signals received by the electromagnetic ultrasonic exciting transducer through the duplexer both pass through the power limiting module and the programmable gain amplifier module to achieve the gain amplification of small signals. Then, after the signals are filtered, they enter the ADC digital acquisition system to convert the received signals into digital quantities, which is convenient for later signal processing to obtain information such as phase holdup and phase velocity in multiphase flow.

[0128] 6. Process the received signals. The signals obtained by the electromagnetic ultrasonic receiving transducer and the electromagnetic ultrasonic exciting transducer can be synchronously processed. The ultrasonic signals that are reflected or attenuated from the fluid and reach the pipe wall again will be transmitted to the electromagnetic ultrasonic transducers on both sides respectively, so that there is a definite time sum. According to the definite time sum, compensation can be made for the fitting of the ultrasonic signal envelope, making the calculation in time more accurate and improving the measurement accuracy.

[0129] In the present invention, flexible coils with different parameters can also be used to select wave modes with different frequency matching conditions. In this way, the frequency multiplexing method can be adopted to change the deflection angle of ultrasonic waves to obtain more multiphase flow information for different propagation paths and improve the accuracy of measurement results.

[0130] In summary, the electromagnetic ultrasonic multiphase flow measurement device and method based on circumferential annular loading of pipelines provided by the embodiments of the present invention have the following beneficial effects:

[0131] (1) The method of full circumferential loading of ultrasonic guided waves realizes the measurement of multiphase flow media in all directions inside the pipeline within the measurement range. At the same time, the electromagnetic ultrasonic receiving transducer and the electromagnetic ultrasonic exciting transducer can be functionally interchanged to realize the forward and reverse path propagation of ultrasonic waves. Compared with traditional piezoelectric ultrasonic detection, the detection accuracy is greatly improved.

[0132] (2) The robustness of the detection system is improved, and it can work in harsh environments (such as high temperature and low temperature). At the same time, the flexible coil can adapt to different pipe diameters.

[0133] (3) According to the actual situation of electromagnetic ultrasonic guided wave detection for multiphase flow, this situation of micro-bent pipelines can be measured.

[0134] (4) There is a definite time interval between the electromagnetic ultrasonic excitation transducer and the electromagnetic ultrasonic receiving transducer in ultrasonic signal reception, which can be used as a reference and compensation for the fitting of the ultrasonic signal envelope, improving the envelope fitting accuracy and measurement precision of multiphase flow measurement.

[0135] (5) By adopting a pneumatic annular electromagnetic ultrasonic transducer clamping device, the entire electromagnetic ultrasonic multiphase flow measurement device based on circumferential annular loading of the pipeline is simpler, more convenient, and easier to install.

[0136] It should be noted that similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0137] In addition, in the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", and "couple" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0138] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electromagnetic ultrasonic multiphase flow measurement device based on circumferential annular loading of a pipeline, characterized in that It includes a signal generating device, an electromagnetic ultrasonic excitation transducer using a flexible coil, an electromagnetic ultrasonic receiving transducer using a flexible coil, and a signal processing device, which are connected in sequence. The electromagnetic ultrasonic excitation transducer and the electromagnetic ultrasonic receiving transducer are arranged at different positions of the pipeline to be measured at a preset distance, and are both arranged along the circumferential section of the pipeline to be measured and around the outer wall of the pipeline to be measured. The signal generating device is used to generate an excitation electrical signal. The electromagnetic ultrasonic excitation transducer is used to convert the excitation electrical signal into an ultrasonic signal in the pipe wall of the pipeline to be measured. The electromagnetic ultrasonic receiving transducer is used to convert the ultrasonic signal received from the inside of the pipeline to be measured into a received electrical signal. The signal processing device is used to perform signal processing on the received electrical signal to obtain the multiphase flow detection result corresponding to the pipeline to be measured. Both the electromagnetic ultrasonic excitation transducer and the electromagnetic ultrasonic receiving transducer fasten the flexible coil on the pipeline to be measured through a pneumatic annular electromagnetic ultrasonic transducer clamping device. The pneumatic annular electromagnetic ultrasonic transducer clamping device includes an annular airbag. The inner side of the airbag is the flexible coil, and a connecting row buckle is arranged on the outer side of the airbag, and the connecting row buckle is used to adapt to different pipeline diameters. The signal processing device includes a power limiting module, a programmable gain amplification module, a variable filter, and an ADC digital acquisition system, which are connected in sequence. The signal processing device is used to perform power limiting, amplification, filtering, and analog-to-digital conversion on the received electrical signal in sequence through the power limiting module, the programmable gain amplification module, the variable filter, and the ADC digital acquisition system to obtain a digital detection signal, and determine the multiphase flow detection result corresponding to the pipeline to be measured based on the digital detection signal and a predetermined corresponding relationship curve between the ultrasonic attenuation coefficient and the phase content rate.

2. The electromagnetic ultrasonic multiphase flow measuring device based on circumferential annular loading of a pipeline according to claim 1, characterized in that When the pipeline to be measured is a non-ferromagnetic metal material, both the electromagnetic ultrasonic excitation transducer and the electromagnetic ultrasonic receiving transducer include a flexible coil and a permanent magnet arranged in a concentric ring shape from the inside to the outside. When the pipeline to be measured is a ferromagnetic metal material, both the electromagnetic ultrasonic excitation transducer and the electromagnetic ultrasonic receiving transducer include a first permanent magnet, a flexible coil, and a second permanent magnet arranged in sequence along the axial direction of the pipeline to be measured, and the first permanent magnet, the flexible coil, and the second permanent magnet are all annular. When the pipeline to be measured is a non-metal material, both the electromagnetic ultrasonic excitation transducer and the electromagnetic ultrasonic receiving transducer include a first permanent magnet, a flexible coil, and a second permanent magnet arranged in sequence along the axial direction of the pipeline to be measured, and the first permanent magnet, the flexible coil, and the second permanent magnet are all annular, and a magnetostrictive material is arranged inside the flexible coil.

3. The electromagnetic ultrasonic multiphase flow measuring device based on circumferential annular loading of a pipeline according to claim 1, wherein The signal generating device includes an arbitrary function generator and a high-power pulse signal amplification module connected to each other. The arbitrary function generator is used to generate a basic electrical signal with a certain frequency. The high-power pulse signal amplification module is used to amplify the basic electrical signal into a high-voltage and large-current signal.

4. The electromagnetic ultrasonic multiphase flow measuring device based on circumferential annular loading of a pipeline according to claim 1, wherein A first impedance matching module is provided between the signal generating device and the electromagnetic ultrasonic excitation transducer, and a second impedance matching module is provided between the electromagnetic ultrasonic receiving transducer and the signal processing device.

5. The electromagnetic ultrasonic multiphase flow measurement device based on circumferential annular loading of a pipeline according to any one of claims 1-4, characterized in that, A first duplexer is provided between the signal generating device and the electromagnetic ultrasonic excitation transducer, and the first duplexer is also connected to the signal processing device; a second duplexer is provided between the electromagnetic ultrasonic receiving transducer and the signal processing device, and the second duplexer is also connected to the signal generating device.

6. An electromagnetic ultrasonic multiphase flow measurement method based on circumferential annular loading of a pipeline, characterized in that Applied to the electromagnetic ultrasonic multiphase flow measurement device based on circumferential annular loading of a pipeline according to any one of claims 1-5; the electromagnetic ultrasonic multiphase flow measurement method based on circumferential annular loading of a pipeline includes: Obtain the received electrical signal and the echo time output by the electromagnetic ultrasonic receiving transducer; wherein, the echo time is the propagation duration of the ultrasonic signal received by the electromagnetic ultrasonic receiving transducer. Determine the ultrasonic attenuation coefficient according to the received electrical signal, and determine the phase fraction corresponding to the pipeline under test according to the ultrasonic attenuation coefficient. Calculate the flow velocity corresponding to the pipeline under test according to the echo time.

7. The electromagnetic ultrasonic multiphase flow measurement method based on circumferential annular loading of a pipeline according to claim 6, wherein When the flow pattern of the multiphase flow corresponding to the pipeline under test is stratified flow, the electromagnetic ultrasonic multiphase flow measurement method based on circumferential annular loading of a pipeline further includes: Calculate the liquid level height of the interface in the pipeline under test according to the echo time.

8. The electromagnetic ultrasonic multiphase flow measurement method based on circumferential annular loading of a pipeline according to claim 6, characterized in that Before obtaining the received electrical signal and the echo time output by the electromagnetic ultrasonic receiving transducer, the electromagnetic ultrasonic multiphase flow measurement method based on circumferential annular loading of a pipeline further includes: Obtain the characteristic parameters of the pipeline under test, and the characteristic parameters include material properties, inner radius, and outer radius. Determine the wire pitch of the flexible coil and the frequency of the excitation electrical signal according to the characteristic parameters. Fabricate the electromagnetic ultrasonic excitation transducer and the electromagnetic ultrasonic receiving transducer according to the wire pitch of the flexible coil. Determine the operating frequency of the signal generating device according to the frequency of the excitation electrical signal.

Images