WO2017078559A1

WO2017078559A1 - Ultrasonic flow meter sensor

Info

Publication number: WO2017078559A1
Application number: PCT/RU2015/000732
Authority: WO
Inventors: Вакиф Карамович ХАМИДУЛЛИН
Original assignee: Вакиф Карамович ХАМИДУЛЛИН
Priority date: 2015-11-02
Filing date: 2015-11-02
Publication date: 2017-05-11

Abstract

The utility model relates to measuring technology and can be used for measuring the flow rate of media in different fields of industry which involve the pipeline transportation of liquid and gas media, such as the oil refining industry and the oil and gas extraction industry, as well as in public utility systems, and in the energy industry. The present ultrasonic flow meter sensor comprises a measuring portion of a pipe with a flow passage which has a polygonal cross-section and electroacoustic transducers that are spaced apart from one another in the inlet and outlet parts of the measuring portion. The sensor is characterized in that the measuring portion is made entirely of metal or of plastic and is configured such that the polygonal cross-section of the flow passage has an even number of sides; at opposite ends of each pair of parallel sides, in a transverse depression in the material of the wall of the flow passage, there are mounted at least two rectangular electroacoustic transverse wave transducers with identical angles of inclination to the horizontal axis at a distance or three or four diameters of the pipeline, each of which is separated from the flow passage by a resonant connector, wherein on the surface of the measuring portion of the pipeline there is provided an acoustic interference absorber in the form of a comb structure with a spacing equal to or greater than half a wavelength.

Description

SENSOR FOR ULTRASONIC FLOW METER

The invention relates to measuring technique and can find application for measuring the flow rate of media in various industries related to the transportation of liquid and gaseous media through pipelines, for example, in the oil refining, oil and gas producing sectors, in housing and communal services, energy.

A known sensor of an ultrasonic flow meter (see US patent N ° 7360448, claimed 10.08.2006, publ. 04/22/2008) containing a measuring section of the pipeline and two ring-shaped electroacoustic transducers (hereinafter - EAP) mounted coaxially at the ends of the measuring section for sensing the flow along and against the flow by providing multiple intersection of the flow along the entire cross section with the path of movement of ultrasonic waves, accompanied by multiple reflections and refractions of these waves in the wall of the flow part and visual area.

The disadvantage of this device is the reduced measurement accuracy due to significant spurious interference arising in the wall of the flowing part at each reflection and refraction of the probe signal, which in this case splits into longitudinal and transverse waves and circulates in the wall until complete attenuation.

The closest in technical essence to the proposed solution is an ultrasonic flow meter sensor (see USSR author's certificate N ° 1 185091, application form 13.07.1983, publ. 06.15.1985) containing a measuring section of the pipeline with a flowing part having a square cross section and two EAP electroacoustic transducers located separately and symmetrically in the windows of the inclined walls of the input part and the output parts. The input part of the measuring section is made in the form of a diffuser with expansion only on two opposite sides, and the output part is in the form of a confuser with a narrowing on the same sides, and the EAPs are located on the inclined sides of the diffuser and confuser flush with them.

The disadvantage of this device is the significant error in the measurement of flow due to the distortion of the flow velocity profile by the diffuser and confuser. Another disadvantage of the known device is the restrictions on the pressure and temperature of the controlled media due to the installation of these EAFs in two through holes in the diffuser and confuser.

The technical result of the proposed solution is to increase the accuracy of measuring the flow rate of liquid and gaseous media in pipelines under changing conditions temperature and pressure of the controlled medium due to sounding of the flow over the entire cross section of the flow part of the sensor and effective averaging of the flow velocity profile over the entire cross section of the flow part. The high accuracy of averaging the flow velocity profile is ensured by multiple intersection over the entire cross section of the flow part by integrating the velocity profile V (x, y) not only along the propagation path of the acoustic wave, but also along the length of the electro-acoustic transducer, i.e., the proportionality coefficient K between the measured flow rate and the true value is close to unity with an accuracy of tenths of a percent.

= Req (Re) / Vcp (Re),

TRevcp. Ke. (Re) is the average speed of the controlled flow, measured using a sensor with a square cross-section, depending on the Reynolds number Re, V (x, y) is the distribution function of the flow velocities in the cross section of the flow part, S is the cross-sectional area of the flow part, Vcp. (Re) - the average speed of the controlled flow depending on the number Re, measured by a reference flow meter.

An ultrasonic flowmeter sensor is proposed, comprising a measuring section of a pipeline with a flowing part having a cross-section (including square) in the form of a polygon with an even number of faces, at least two rectangular ones are installed at the opposite ends of each pair of parallel faces in the transverse recess in the material of the wall of the flowing part transverse electro-acoustic transducers with the same inclination angles mainly from 45 to 65 ° to the longitudinal axis at a distance of 3 or 4 pipe diameters length and length equal to the width of the face.

Moreover, each of the electro-acoustic transducers is separated from the flow part by a resonant jumper equal to half the wavelength of the carrier frequency of the probing signal.

In order to attenuate the acoustic noise arising inside the walls of the flowing part during each reflection and refraction of the probe signal, which splits into longitudinal and transverse waves and circulates in the wall until it is completely attenuated, an acoustic noise absorber in the form of a periodic comb structure with in steps equal to or greater than half the wavelength in the wall material. PT / RU2015 / 000732

The figures show: FIG. 1 - construction of the proposed sensor of an ultrasonic flow meter with a 4-sided flow part and one acoustic channel, FIG. 1a is the propagation path of an acoustic wave in the flow part of the sensor; FIG. 2 is a design of a single-channel sensor in cross section AA, FIG. 3 shows a sensor construction with a 4-sided flowing part and four acoustic channels in a section in a vertical plane, FIG. 4 is a design of a sensor with a 4-sided flow part and four acoustic channels with a partial section, FIG. 5 is a design of a 4-channel sensor in cross section A-A, FIG. 6 is a design of a 4-channel sensor in cross-section B-B, FIG. . 7 - design of the sensor with a flowing part having a cross-section in the form of an octagon; Fig. 8 - construction of a sensor with an 8-sided flowing part in a cross-section AA, Fig. 9 - construction of a sensor with an 8-sided flowing part in a transverse section BB.

In FIG. 1 shows the design of the proposed sensor of an ultrasonic flow meter with one acoustic channel. The sensor consists of an all-metal measuring section of the pipeline 1 (from titanium, stainless steel, plastic or other material) in the form of a segment of the pipeline with a flowing part 2 having a square cross section. On the surface of two opposite sides of the measuring section of the pipeline 1, formed by two parallel faces of the flowing part 2, an acoustic noise absorber is made in the form of a comb structure 3 to eliminate interference caused by ultrasonic waves 1 1 reflected inside the metal. At the opposite ends of the measuring section of the pipe 1 in one diametrical plane in the walls of the flow part 4 and 9 in the recess are made of two identical sites, strictly parallel to each other, with equal angles of inclination of 4 5 to 65 ° to the surfaces of the longitudinal axis of the flow part 2. Each area is separated from the flow part 2 by resonant jumpers 6 and 7 having a minimum thickness that is a multiple of half the wavelength of the carrier of the probe signal. At each of these sites, electro-acoustic transducers of transverse (shear) waves 5 and 8 are installed symmetrically relative to the indicated diametrical plane of the measuring section of the pipeline 1. The propagation path of the probing signal is indicated by the number 10. The propagation of the probing signal can occur:

1) without reflection of the signal from the walls of the flow part, i.e. with one beam

2) with two reflections of the signal from the walls of the flow part, i.e. with three beams as shown in FIG. 6; 3) with four reflections of the signal from the walls of the flow part, i.e., with five rays. Obviously, by the number of rays we mean the number of segments of which the indicated trajectory consists.

In FIG. 2 shows the design of the sensor in cross section AA, from which it follows that the jumper 7 has a uniform thickness equal to half the wavelength in the transverse direction relative to the longitudinal axis of the flow part 2. This design ensures the coherence of the waves refracted in the wall of the flow part 9 and a large beam pattern of the probe signal emitted into the stream.

When probing a controlled medium in a flow having a speed V, B, an EAP 8 is used as an emitter, and an EAP 5 is used as a receiving element. A pulsed ultrasonic signal emitted by an EAP 8 in the form of a shear wave packet passes through a wall 9 representing a prism, then in the form of a longitudinal wave repeatedly crosses the flow of the controlled medium over its entire cross section and then passes into the transverse wave and refracts in the wall of the Measuring section of the pipeline 1 reaches EAP 5. Moreover, with the help of The electronic unit measures the propagation time of the ultrasonic signal along the stream. In a similar way, the controlled medium is probed against the flow and the propagation time of the ultrasonic signal against the flow is measured using EAP 5 as the emitter and EAP 8 as the receiving element. The difference in the propagation time of the ultrasonic signal along the flow and against the flow determines the flow rate of the controlled medium.

The accuracy of the flow measurement is achieved by sensing the flow over the entire cross section of the flow part of the sensor and effectively averaging the flow velocity profile and is evaluated in comparison with the indications of the reference flow meter.

K = JJV (x, l) dxdl / V _3m Si, (2)

(si)

where V (x, / ^ is the projection of the flow velocity profile along the acoustic beam in the longitudinal section x, Si = L * a is the inclined area through which the sonicated stream passes in the flow part of the sensor, L is the length of the acoustic beam, and is the width of the face of the flow parts, Wet is the average speed of a controlled flow measured by a reference flowmeter.

In FIG. 3, 4, 5, a design of a 4-channel sensor with a 4-sided flowing part of an ultrasonic flowmeter is presented, symmetrical in two mutually perpendicular planes relative to the longitudinal axis of the sensor, which are also perpendicular to the corresponding faces of the flowing part, which makes it possible to average the profile of the flow velocity and pulsations along two planes and, accordingly, increase the accuracy of the flow measurement. In FIG. 3, the structure is shown in section in the vertical plane, and in FIG. 4 with a partial cut. The sensor consists of an all-metal measuring section of the pipeline 1 in the form of a segment of the pipeline with a flowing part 2 having a square cross section. The cylindrical surface 3 of the measuring section of the pipeline 1 has a wavy structure made in the form of a spiral thread. In the first acoustic channel, EAPs 8 and 5 are used as receiving-emitting elements; in the second EAP 13 and 15; in the third, EAP 12 and 17; in the fourth EAP 14 and 16 in accordance with Fig.5. The sensor operates as follows. The flow measurement cycle with a 4-channel sensor includes sequential measurement of the difference in the propagation time of the probing ultrasonic signal along and against the flow by each acoustic channel. In the first acoustic channel, the measurement of the indicated time in the flow is performed using the EAP 8 as the emitter and the EAP 5 as the receiving element, and when measured against the flow-EAP 5, the emitter and the EAP 8 are the receiving element, then the difference of these measured time intervals is determined. In the second acoustic channel, a similar process is carried out using EAPs 13 and 15, in the third channel using EAPs 12 and 17, in the fourth - using EAPs 14 and 16. The averaged data obtained by the four acoustic channels is a measure of flow. In the proposed sensor in each channel, sounding occurs along three plane rays, as shown in FIG. Thus, in the case of a 4-channel sensor in one flow measurement cycle, the monitoring of the controlled flow and averaging are performed 12 times.

With an increase in the diameter of the measuring section of the pipeline, the relations between the diameter and the size of the EAA (length) are determined by the formula (3):

H / D = sin (7E / n), (3)

where H is the width of the polygon face, D is the conditional diameter of the flow part, and n is the even number of faces of the polygon.

In FIG. 7, 8, 9 show the design of a 4-channel sensor of an ultrasonic flow meter with a flow part having a cross section in the form of an octagon.

Four acoustic channels are built on four parallel pairs of faces in such a way as to “sound” the flow over the entire cross section.

This provides the possibility of averaging the profile of the flow velocity and pulsations and, accordingly, increasing the accuracy of flow measurement in pipelines of larger diameter. In FIG. 7, the structure is shown in section in a vertical plane. The sensor consists of an all-metal measuring section of the pipeline 1 in the form of a segment of the pipeline with a flowing part 2 having a cross section in the form of an octagon. The surface of the measuring section of the pipeline 1 has an acoustic noise absorber in the form of a comb structure 3, made in the form of a spiral thread. In the first acoustic channel, EAPs 8 and 5 are used as receiving-emitting elements; in the second EAP 13 and 15; in the third, EAP 12 and 17; in the fourth-EAP 14 and 16 in accordance with Fig and 9.

The sensor operates as follows.

The flow measurement cycle of the sensor shown in FIG. 7, 8, 9, includes sequential measurement of the propagation time difference of the probing ultrasonic signal in and against the flow of each acoustic channel. In the first acoustic channel, the measurement of the specified time in the flow is performed using the EAP 8 as the emitter and the EAP 5 as the receiving element, and when measured against the flow, the EAP 5 is the emitter and the EAP 8 is the receiving element, then the difference of these measured time intervals is determined. In the second acoustic channel, a similar process is carried out using EAPs 13 and 15, in the third channel using EAPs 12 and 17, in the fourth - using EAPs 14 and 16. The averaged data obtained by the four acoustic channels are a measure of the flow rate.

Improving the accuracy of flow measurement using the proposed sensor of an ultrasonic flow meter is due to:

1) the installation of the EAP with a deepening in the wall of the flow part and ensuring the thickness of the resonant jumper separating the EAT from the flow part equal to half the wavelength of the carrier frequency, which allows you to get a wide radiation pattern in the longitudinal plane for the probe signal at the entrance to the stream;

2) a significant attenuation of acoustic noise arising inside the walls of the flowing part during each reflection and refraction of the probe signal, which is split into longitudinal and transverse waves and circulates in the wall until it is completely attenuated due to the implementation of an acoustic noise absorber on the surface of the measuring section of the pipeline in the form of a comb structure ;

3) multiple (in terms of the number of rays) sounding of the flow over the entire cross section of the flow due to the flow part with a polygonal cross section.

Claims

CLAIM

1. The ultrasonic flow meter sensor containing a measuring section of the pipeline with a flowing part having a cross section in the form of a polygon and electro-acoustic transducers (EAP) located separately from each other in the input and output parts of the measuring section,

characterized in that the measuring section is made all-metal or plastic in such a way

that the cross section of the flowing part of the specified polygon is made with an even number of faces,

at the opposite ends of each pair of parallel faces in a transverse recess in the material of the wall of the flowing part, at least two rectangular electro-acoustic transducers of transverse waves with the same angles of inclination to the longitudinal axis at a distance of three or four pipe diameters are installed,

each of which is separated from the flow part by a resonant jumper, while on the surface of the measuring section of the pipeline an acoustic noise absorber is implemented in the form of a comb structure with a step equal to or greater than half the wavelength.