CN104090020A - Electric and ultrasonic-based bimodal multiphase flow measuring device - Google Patents

Abstract

The invention belongs to the technical field of fluid measurement, and relates to an electrical and ultrasonic dual-mode multi-phase flow measurement device, including an electrical sensor array, an ultrasonic sensor array, an electrical signal generation and detection unit, an ultrasonic signal generation and detection unit, and a flow parameter calculation unit ; The electrical sensor array includes two groups of electrode arrays distributed in different cross-sectional positions of the measured pipeline, each group of electrodes is composed of one or more electrodes distributed in the same cross-sectional position of the measured pipeline; the ultrasonic sensor array includes two groups of ultrasonic probes Each group of probe arrays is composed of multiple probes distributed at the same cross-sectional position of the pipeline under test; electrical electrodes and ultrasonic probes are installed and work simultaneously on the pipeline under test to form a set of dual-mode sensors. The measuring device of the invention has the characteristics of wide application range, visualization, low cost and the like.

Description

Dual-mode Multiphase Flow Measurement Device Based on Electricity and Ultrasonic

technical field

The invention belongs to the technical field of fluid measurement, and relates to an electrical and ultrasonic dual-mode multiphase flow measurement device, which can realize the online acquisition of parameters such as phase holdup and flow velocity of multiphase flow and the monitoring of the flow state. The present invention takes the measurement of oil/gas/water multiphase flow as the description object, but it is not limited to this application, and the measurement device of the present invention is still applicable to the multiphase flow phenomena existing in other industrial processes and chemical reactions. the

technical background

Multiphase flow phenomena widely exist in industrial production and daily life. The "phase" in multiphase flow is defined as the existence form of substances, that is, gaseous, liquid or solid, so multiphase flow is a fluid with two or more "phase" substances flowing at the same time. Multiphase flow phenomena widely exist in industrial processes such as energy, power, petroleum, chemical industry, metallurgy, and medicine, and play a very important role in industrial production and scientific research. Its flow process monitoring and description, as well as the flow process parameters Accurate detection also presents challenges for engineers and researchers. In recent years, international research interest in multiphase flow has continued to grow. The reason is that multiphase flow is not only widely used in a series of modern engineering, but also plays an important role in promoting the development and innovation of these engineering equipment. the

Due to the interface effect and relative velocity between the phases of multiphase flow, the phase interface changes randomly in time and space, resulting in the flow characteristics of multiphase flow being far more complex than single-phase flow, and the characteristic parameters are also more than single-phase flow. The multiphase flow process parameter detection strategy varies with the working conditions and object attributes, and there are many physical phenomena and relationships that can be used, so the detection methods are also diverse. Detection methods can be divided into two categories: direct method and indirect method. The direct method means that the object parameters can be directly obtained through measurement, while the indirect method needs to establish a relationship between the measured value (auxiliary measured value) and the measured parameter through calculation, that is, the "soft measurement" method. In the field of multiphase flow measurement, many detection methods that directly use single-phase flow instruments are direct methods, while emerging detection technologies mostly use soft measurement methods, such as electrical methods, ultrasonic methods, and ray methods. In scientific research and industrial applications, multiphase flow detection methods need not cause any disturbance to the measured fluid. Therefore, electrical methods and ultrasonic methods have attracted much attention due to their simple structure, non-disturbance, and low cost. the

Electrical measurement methods are divided into various forms according to the sensor structure, shape, and excitation method, such as conductance probes, annular conductance arrays, etc. Among them, the rotating field electrical impedance method, that is, the electrical process tomography technology, is one of the electrical methods. It is an important improved form, which can provide rich material cross-sectional distribution information, and can reconstruct the distribution of multiphase media in opaque pipes visually. In addition, this technology has the characteristics of non-disturbance and multi-point measurement, and can realize the process parameters such as phase holdup and flow velocity of the measured multiphase fluid, and has a good application prospect. Electrical process tomography technology is divided into capacitive, resistive, impedance and electromagnetic tomography according to different measurement sensitivity principles. the

Ultrasonic testing is a widely used technology. It has its unique advantages in medical monitoring and fluid measurement. Ultrasonic waves will not destroy the flow field of the fluid when it propagates in the fluid, and there will be no pressure loss. At the same time, if the detection element is placed in the pipeline The outer wall can avoid direct contact with the fluid and reduce the corrosion of the sensor. The ultrasonic tomography method can obtain the distribution information of different acoustic impedance media inside the measured section in a non-perturbed form through multiple ultrasonic transceiver probes installed at the same section of the pipeline. the

Contents of the invention

The purpose of the present invention is to provide a device capable of accurately and undisturbedly measuring multiphase flow parameters, and obtain more abundant information of the multiphase flow process by using a dual-mode array sensor. The present invention uses a sensor array based on electrical and ultrasonic sensitive principles to extract multiphase flow flow information, and uses the measurement principle that electrical sensors are sensitive to changes in conductivity/permittivity to obtain the distribution of high conductivity phase (water phase) of oil, gas and water multiphase flow Information, using the measurement principle that the ultrasonic sensor is sensitive to the change of acoustic impedance to obtain the distribution information of the acoustic impedance (gas phase) of the oil-gas-water multiphase flow, and applying information fusion technology to process the above multi-source information, without disturbing the multiphase flow and without The fluid is pre-separated or mixed to realize the calculation of the phase distribution and flow velocity distribution of the multiphase flow process. the

Technical scheme of the present invention is as follows:

An electrical and ultrasonic dual-mode multi-phase flow measurement device, used for measuring multi-phase fluid flowing through the pipeline under test, the measurement device used includes an electrical sensor array, an ultrasonic sensor array, an electrical signal generation and detection unit, and an ultrasonic signal generation and a detection unit and a flow parameter calculation unit; the electrical sensor array includes two sets of electrode arrays distributed at different cross-sectional positions of the pipeline under test, each group of electrodes is composed of one or more electrodes distributed at the same cross-sectional position of the pipeline under test, The two groups are respectively an upstream electrical sensor array and a downstream electrical sensor array; the ultrasonic sensor array includes two groups of probe arrays distributed at different cross-sectional positions of the measured pipeline, and each group of probe arrays is composed of a plurality of ultrasonic probes, and the two groups are respectively The upstream ultrasonic sensor array and the downstream ultrasonic sensor array; the electrical sensor array and the ultrasonic sensor array work simultaneously to form a set of dual-mode sensor arrays; the electrical signal generation and detection units alternately gate two pairs of electrodes belonging to different groups of electrical sensor arrays as An excitation electrode pair, one of which is an excitation electrode and the other is a ground electrode, an electrical sensitive field is established between the excitation electrode pair, and the potential difference between the remaining electrodes is measured; the ultrasonic signal generation and detection unit gates an ultrasonic probe each time Generate ultrasonic waves, gate one or more probes that do not belong to the same group as the ultrasonic probe to receive ultrasonic waves, and convert the ultrasonic intensity into electrical signals; the potential difference measured by the electrical signal generation and detection unit and the signal obtained by the ultrasonic signal generation and detection unit Together, it is sent to the flow parameter calculation unit for phase holdup and flow velocity calculation

The information detection technology based on the principle of electrical sensitivity is sensitive to changes in the electrical properties of the measured fluid, such as electrical conductivity or dielectric constant, but the boundary information between the gas-liquid phase with a large density difference is fuzzy and difficult to obtain. In multiphase flow, due to the huge difference in acoustic impedance at the interface between the gas phase and the liquid phase, the reflection characteristics of ultrasound at the gas-liquid interface are extremely obvious (up to 99%), so ultrasound has an excellent resolution ability for the gas-liquid interface. . Therefore, the sensor array based on the principle of electrical sensitivity is combined with the sensor array based on the principle of ultrasonic sensitivity. The electrical sensor array is used to obtain the electrical parameter distribution (usually the water phase distribution in the liquid phase), and the ultrasonic sensor array is used to obtain the acoustic impedance distribution (usually the gas phase distribution). ), forming a multiphase flow measurement device, which can accurately and comprehensively realize the online identification of multiphase flow flow pattern, online estimation of phase holdup and phase flow velocity while effectively reconstructing the phase distribution and velocity distribution of multiphase flow. Beneficial effects and advantages of the present invention are as follows:

1. The electrical measurement method has a good discrimination effect on the conductivity of multiphase fluids, that is, it is sensitive to the change of the water phase in the oil-gas-water mixture. Ultrasound is sensitive to density changes of multiphase fluids, and the two measurement modes are complementary;

2. This method is a non-invasive measurement method and will not cause any disturbance to the fluid;

3. Multi-sensor arrays can obtain a more comprehensive description of multiphase flow;

4. Fast measurement speed and low cost. the

Description of drawings

The following figures describe selected embodiments of the present invention, all of which are exemplary rather than exhaustive or limiting, wherein:

Fig. 1 (a) and (b) two embodiments of the overall structural diagram of the device of the present invention; Wherein, 0-coming flow direction; Electrodes that can be used alone or in combination, and simultaneously realize capacitance and conductance detection; 3-electrical signal generation and acquisition unit; 4a, 4b-ultrasonic sensor array; 5-ultrasonic signal generation and acquisition unit; 6-flow parameter calculation unit;

Fig. 2 device electric sensor array structural diagram of the present invention, wherein Fig. 2 (a) is the side view of sensor array structure, comprises tested pipeline 1, is installed in the arc electrode array (2a, 2b) of different section positions; Fig. 2 (b ) is a longitudinal A-A cross-sectional view; Figure 2 (c) is a transverse B-B cross-sectional view;

Fig. 3 device ultrasonic sensor array structural diagram of the present invention, wherein Fig. 3 (a) is the side view of sensor array structure, comprises measured pipeline 1 and ultrasonic probe array (4a, 4b); Fig. 3 (b) is longitudinal A-A sectional view; Figure 3(c) is a cross-sectional view of the transverse B-B section;

The ultrasonic and electric dual-mode measurement system structural diagram of Fig. 4 device of the present invention;

Figure 5 is a structural diagram of the device electrical signal generation and detection unit of the present invention;

Figure 6 is a structural diagram of the ultrasonic signal generation and detection unit of the device of the present invention;

Fig. 7 is a functional structural diagram of the computing center of the device of the present invention. the

Detailed ways

The following detailed description of the steps of manufacturing and operating the present invention is intended to be described as an embodiment of the present invention, and is not the only form that can be manufactured or utilized. Other embodiments that can achieve the same function should also be included within the scope of the present invention . The electrical measurement in the present invention includes the detection of resistance, capacitance or electromagnetic information, and several electrical measurement methods can be used simultaneously or separately. the

Embodiments of the present invention will be described in detail below in conjunction with the drawings. the

Fig. 1 has described the overall structural diagram of device of the present invention, comprises a measured pipe section 1, a group of electrical sensor array 2 (2a, 2b) and the electrical signal connected with it occurs in acquisition unit 3, a group of ultrasonic sensor array 4 (4a , 4b) and the ultrasonic signal generation and acquisition unit 5. The electrical sensor array 2 includes two or more electrode arrays distributed on the pipeline under test at certain intervals, and each group of electrodes is composed of a plurality of electrodes distributed at the same cross-sectional position of the pipeline under test; the ultrasonic sensor array 4 includes two groups and More than two groups of ultrasonic probe arrays distributed on the pipeline under test at certain intervals, each group of probes is composed of a plurality of probes distributed at the same cross-sectional position of the pipeline under test; the electrical sensor array 2 and the ultrasonic sensor array 4 Simultaneously installed on the pipeline (can be installed in a cross position) and work simultaneously to form a set of dual-mode sensor arrays without causing any interference to the multiphase flow process. Therefore, the installation sequence of the two types of sensor arrays in the upstream and downstream of the pipeline is different. affect the measurement results. Figure 1(a) and (b) respectively list two examples of the sensor arrangement of the device of the present invention, which are not the only installation structure. In practical applications, the installation sequence can be adjusted according to requirements, and the positions of the electrical sensor array and the ultrasonic sensor array can also be exchanged. , forming at least four typical embodiments. Fig. 1 (a) has described the upstream and downstream of the electrical sensor array 2a, 2b and the ultrasonic sensor array 4a, 4b in the same order as the cross-installation method, wherein the electrical sensor array measurement section 2a and the ultrasonic sensor array measurement section 4a form the upstream sensor array for flow Fusion calculation of parameter visualization information; the measurement section 2b of the electrical sensor array and the measurement section 4b of the ultrasonic sensor array form a downstream sensor array to perform fusion calculation of flow parameter visualization information. Figure 1(b) describes the upstream and downstream symmetrical cross installation of electrical sensor arrays 2a, 2b and ultrasonic sensor arrays 4a, 4b. Fusion calculation of visualized information; the measurement section 2b of the electrical sensor array and the measurement section 4b of the ultrasonic sensor array form a downstream sensor array for fusion calculation of flow parameter visualization information. the

When the measured multiphase flow enters the measured pipe section from the flow direction 0, the electrical sensor array 2 can obtain measurement data containing the fluctuation information of the water phase holdup of the measured fluid through the electrical signal generation and acquisition unit 3, and the ultrasonic sensor array 4 can pass through The ultrasonic signal generating and collecting unit 5 obtains measurement data of gas phase holdup fluctuation information of the measured fluid. The above information is simultaneously sent to the flow parameter comprehensive calculation and visualization unit 6 for flow pattern recognition, to judge whether the continuous phase is conductive, and to use the capacitive sensor or conductivity sensor data in the electrical sensor array 2 according to the judgment result. Select the calculation model according to the flow pattern recognition results, and use the measurement data obtained by the electrical signal generation and acquisition unit 3 and the measurement data obtained by the ultrasonic signal generation and acquisition unit 5 to carry out phase distribution reconstruction, phase holdup extraction, cross-correlation flow velocity distribution reconstruction and flow velocity Extract and display. the

Fig. 2 is the electrical sensor array structure diagram of the device of the present invention, the sensor array is composed of two sets of arc-shaped electrode arrays (2a, 2b) installed in different cross-sectional positions of the tested pipeline 1, and each set of arc-shaped electrode arrays includes Multiple arc electrodes within the same cross-sectional location. The size and number of arc-shaped electrodes in the same section can be changed depending on the application conditions. When working, an excitation signal can be applied to any arc-shaped electrode in the same section, and any other electrode is grounded to form an excitation electrode pair. An electrical measurement sensitive field is formed in the middle of the excitation electrode pair. When the multiphase fluid flows through the sensitive field, due to the change of the electrical parameters in the field with the holdup and distribution of the multiphase medium, the excitation electrode pair and other electrodes The potential difference between them changes accordingly, and the measurement of multiphase flow parameters can be realized by measuring the potential difference. The electrical measurement in the present invention includes the detection of resistance, capacitance or electromagnetic information, and several electrical measurement methods can be used simultaneously or separately. The multi-section electrode array form and combination method adopted are characterized by diversification. Electrodes of different sizes can be installed on different sections to obtain measurement information under different application conditions; electrodes of different sizes can also be installed in the same section to achieve the same section. Therefore, the electrode structure of this device has various forms. The electrical sensor array of the device of the present invention can use excitation signals of different frequencies to realize more comprehensive extraction of multiphase flow information by obtaining the response data of the measured multiphase fluid under different excitation signal frequencies. the

Fig. 3 is the ultrasonic sensor array of the device of the present invention, comprises two sets of ultrasonic probe arrays (4a, 4b) that are installed in different section positions of the pipeline under test to form, and each set of probe arrays includes two sets of probe arrays installed in the same section position of the pipeline under test 1 One or more ultrasound probes. The size and number of ultrasonic probes in the same section can vary depending on the application conditions. When working, an excitation signal can be applied to any probe in the same section, and any other probe can receive an ultrasonic signal to form an excitation electrode pair. The ultrasonic modulation measurement sensitive field is formed in the middle of the exciting electrode pair. When the multiphase fluid flows through the sensitive field, the density of the medium in the field changes with the holdup and distribution of the multiphase medium, resulting in ultrasonic modulation measurement of the ultrasonic intensity in the sensitive field. Corresponding changes occur, and the ultrasonic information is acquired through an acoustic-electric conversion device (such as piezoelectric ceramics, etc.), so as to realize the measurement of multiphase flow parameters. In the multi-section ultrasonic sensor array, the ultrasonic probes that make up the excitation electrode pair can be distributed in the same measured section of the pipeline or in different measured sections, and can be placed between any ultrasonic probes in the ultrasonic sensor array during the measurement process. To switch among them, to realize the comprehensive acquisition of measurement information. the

The ultrasonic sensor array of the device of the present invention can use excitation signals of different frequencies to realize the measurement of liquid droplets and bubbles of different sizes in the multiphase flow, thereby realizing more comprehensive extraction of multiphase flow information. the

Fig. 4 has described the structure of the ultrasonic and electrical dual-mode measurement system of the device of the present invention, including the excitation and detection unit of the electrical sensor array, the excitation and detection unit of the ultrasonic sensor array, the computer bus and the computing center, and the dual mode is realized under the same bus platform Sensor measurement information acquisition. The electrical sensor array excitation and detection unit is used to establish an electrical sensitive field in the measured pipeline 1, and then obtain the water content information of the multiphase flow, which can realize the acquisition of different modal sensor information of electricity and conductance. The specific structure is shown in Figure 5; The excitation and detection unit of the ultrasonic sensor array is used to emit ultrasonic waves to the multiphase fluid in the measured pipeline 1, and then obtain the information of the gas content of the multiphase flow. The specific structure is shown in FIG. 6 . The measurement data obtained by the electrical sensor array excitation and detection unit and the ultrasonic sensor array excitation and detection unit are sent to the computing center through the computer bus for extraction of flow information, calculation of phase holdup and flow velocity, and reconstruction of mobile phase distribution. the

Figure 5 describes the electrical signal generation and detection unit structure. The excitation and signal acquisition of two electrical mode sensors of capacitance and conductance can be realized in the same measurement system. The system control and setting information is transmitted from the computer to the logic control unit through the computer bus, and the overall working logic and parameters of the system are controlled and set through the logic control unit, and the excitation signal is generated in the excitation signal generation module according to the system setting requirements. And the improvement of signal driving ability, that is, using voltage-controlled voltage source (VCVS) or voltage-controlled current source (VCCS) to convert the original excitation signal into a constant voltage or current signal with adjustable amplitude and phase, and through logic control according to certain rules The corresponding electrodes of the capacitance/conductivity electrode array are selected, so that the excitation signal is applied to the measurement space to form an electrical sensitive field. When the multiphase fluid flows through the electrical sensitive field, the electric field intensity distribution changes due to the change of the electrical parameters of the fluid, and then different potential differences will be obtained in the electrode array. The signal demodulation module and the reference signal are used to resolve the potential difference. Adjustment processing, extracting the analog signal containing the change of phase holdup of multiphase flow, and sending it to the analog-to-digital conversion (A/D conversion) array to realize the digitization of the analog signal, and then sending the measurement data to the computing center through the computer bus for realization Calculation of flow parameters. the

Figure 6 describes the structure of the ultrasonic signal generation and detection unit. The system control and setting information is transmitted from the computer to the logic control unit through the computer bus, and the overall working logic and parameters of the system are controlled and set through the logic control unit, and the excitation signal is generated in the excitation signal generation module according to the system setting requirements. . Through the logical control unit, the corresponding probes of the ultrasonic sensor array are gated according to a certain rule, so that the excitation signal generates ultrasonic waves through the electro-acoustic conversion function. A part of the ultrasonic wave is reflected at the liquid interface, and a part of the unreflected ultrasonic wave is received by the receiving probe. The attenuation of the ultrasonic amplitude is directly related to the size of the gas phase in the ultrasonic propagation path, and the signal is shaped by a differential amplification and filter circuit. It is converted into a digital signal through the A/D conversion array, sent to the computing center through the computer bus, and the visual parameter measurement of the multiphase flow process is realized by using the image reconstruction algorithm and the flow parameter calculation model. the

Figure 7 describes the functional structure of the computing center, including the cross-correlation velocity measurement and phase holdup extraction functions of the electrical sensor array and ultrasonic sensor array measurement data, as well as the phase distribution reconstruction and parameter visualization functions in the flow process. The measurement data of the electrical sensor array and the ultrasonic sensor array are sent to their respective cross-correlation flow velocity and phase holdup calculation units to obtain the flow velocity and phase holdup information, and at the same time, the information fusion and integration of the measurement data of the electrical sensor array and the ultrasonic sensor array are carried out. Phase distribution reconstruction; or first conduct phase distribution reconstruction of electrical and ultrasonic measurement data information fusion, and then use the phase distribution reconstruction results to perform pixel cross-correlation flow velocity calculation to realize flow velocity distribution reconstruction, and then obtain the phase holdup and phase separation velocity information of the measured flow . The flow velocity and phase holdup information obtained by using the electrical sensor array and the ultrasonic sensor array are sent to parameter synthesis and visual display together with the reconstructed phase distribution results to realize the summary and visual output of the final results. the

Claims (1)

1. an electricity and ultrasonic double-mode state multiphase flow measuring device, for the heterogeneous fluid of the tested pipeline of flowing through is measured, measurement mechanism used comprises electric sensor array, ultrasonic sensor array, electrical signal generation and detecting unit, ultrasonic signal generation and detecting unit, flow parameter computing unit; Described electric sensor array comprises two groups of electrod-arrays that are distributed in tested pipeline different cross section position, every group of electrode consists of one and one electrode that is distributed in above tested pipeline same cross-sectional position, and two groups are respectively upstream electricity sensor array and downstream electricity sensor array; Described ultrasonic sensor array comprises two groups of linear transducer arrays that are distributed in tested pipeline different cross section position, and every group of linear transducer array consists of a plurality of ultrasonic probes, and two groups are respectively upstream ultrasonic sensor array and downstream ultrasonic sensor array; Electric sensor array, ultrasonic sensor array are worked simultaneously, form a set of bimodal sensor array; Electrical signal occurs to replace gating with detecting unit and adheres to not on the same group two of electric sensor array pairs of electrodes separately as exciting electrode pair, one of them electrode is exciting electrode, another electrode is ground-electrode, described exciting electrode between set up electricity sensitivity field, measure electric potential difference between remaining electrode; Ultrasonic signal occurs to produce ultrasound wave with ultrasonic probe of the each gating of detecting unit, and one or more probes that gating and this ultrasonic probe do not belong on the same group receive ultrasound wave, and ultrasound intensity is converted to electric signal; Electrical signal occurs to occur with together with signal that detecting unit obtains with ultrasonic signal with electric potential difference that detecting unit is surveyed, and sends into the calculating that flow parameter computing unit carries out phase content and flow velocity.