RU231471U1 - Ultrasonic water meter flow forming device - Google Patents

Abstract

The utility model relates to the field of measuring the volumetric flow rate and volume of liquid in pressure pipelines, namely to the structural elements of equipment for measuring the volumetric flow rate and volume of liquid in pressure pipelines. The flow forming device of the ultrasonic water meter contains a plastic insert consisting of two joined parts with a length of L = 70 mm and diameters of the input and output apertures of D = 18 mm, wherein the insert is a generatrix that fixes the positions of three metal acoustic mirrors with overall dimensions of 9.8 mm by 7.8 mm, a thickness of 0.5 mm and a radius of curvature in the plane of the long side of R = 150 mm and two ultrasonic sensors - the left one, with an area of the radiated surface of Sl = 59 mm ² , a radius of curvature of the spherical radiating surface of Rl = 120 mm, a height of hl = 9 mm and the right one, with an area of the radiated surface of Sp = 41 mm ² , a radius of curvature of the spherical radiating surface of Rp = 120 mm, a height of hp = 11.4 mm, such that the distance from the center of the radiating surface of the left ultrasonic sensor to the center of the first acoustic mirror is greater than the distance from the center of the radiating surface the right ultrasonic sensor to the center of the third acoustic mirror, and the centers of the first, second and third acoustic mirrors form a non-equilateral triangle, in which the side between the centers of the first and second acoustic mirrors is greater than the side between the second and third acoustic mirrors, and the base of the triangle between the centers of the first and third acoustic mirrors is greater than the sides of the first-second acoustic mirrors and the second-third acoustic mirrors, wherein the cross-sectional area of the space formed by the flow forming device of the ultrasonic water meter, filled with a moving measured medium, namely the flow region, changes along the central axis, and the change in the cross-sectional area of the flow region does not have a periodicity. The technical result of the claimed utility model is a reduction in flow pressure losses with its simultaneous stabilization and resistance to distortion. 8 fig.

Description

Field of technology

The utility model relates to the field of measuring the volumetric flow rate and volume of liquid in pressure pipelines, namely to the structural elements of equipment for measuring the volumetric flow rate and volume of liquid in pressure pipelines.

State of the art

An ultrasonic flowmeter for measuring the flow rate of a liquid is known from the prior art and includes a flow tube through which a measured liquid flows, a first sensor intended to transmit an ultrasonic pulse through the liquid flowing through the tube, a second sensor intended to transmit another ultrasonic pulse through the liquid flowing through the tube, a reflector located in the tube, wherein the reflector is configured to reflect the ultrasonic pulse transmitted by the first transducer from the second transducer to obtain an upward flow pulse with a flight time, and to reflect the ultrasonic pulse transmitted by the second transducer from the first transducer to obtain a downward flow pulse with a flight time, a microcontroller connected to the first and second transducers in such a way that the microcontroller causes the first and second transducers to transmit ultrasonic pulses of upward and downward flows and generates a measurement of the flight time of the upward and downward flows, wherein the microcontroller receives a plurality of sequences of said measurements, each of which includes at least three measurements of the flight time upstream and downstream, wherein at least three measurements relate to one and the same type of measurements selected from a separate group (see EP 3611480 A1, 19.02.2020).

The disadvantage of this source is the large pressure loss of the flow, since the flow area of the ultrasonic flow meter is made symmetrical.

The closest analogue to the claimed solution is the ultrasonic flow meter for measuring liquid flow Ultrimis UL2.5. (see https://www.apator.com/en/our-solutions/water-and-heat/water-meters/ultrasonic/ultrasonic-water-meter#application), which contains a device for forming the flow of an ultrasonic water meter, formed by an internal flow volume, which contains a plastic insert, ultrasonic sensors and acoustic mirrors, while the flow area is made symmetrical.

The disadvantage of this source is the large pressure loss of the water flow, since the flow area of the ultrasonic flow meter is made symmetrical.

Disclosure of a utility model

The technical result of the claimed utility model is a reduction in water flow pressure losses with simultaneous stabilization and resistance to distortion.

The above technical result is achieved by a flow forming device of an ultrasonic water meter containing a plastic insert consisting of two joined parts with a length of L = 70 mm and diameters of the input and output apertures of D = 18 mm, wherein the insert is a generatrix that fixes the positions of three metal acoustic mirrors with overall dimensions of 9.8 mm by 7.8 mm, a thickness of 0.5 mm and a radius of curvature in the plane of the long side of R = 150 mm and two ultrasonic sensors - the left one, with an area of the radiated surface of Sl = 59 mm ² , a radius of curvature of the spherical radiating surface of Rl = 120 mm, a height of hl = 9 mm and the right one, with an area of the radiated surface of Sp = 41 mm ² , a radius of curvature of the spherical radiating surface of Rp = 120 mm, a height of hp = 11.4 mm, such that the distance from the center of the radiating surface of the left ultrasonic sensor to the center of the first acoustic mirror is greater than the distance from the center of the radiating surface of the right ultrasonic sensor to the center of the third acoustic mirror, and the centers of the first, second and third acoustic mirrors form a non-equilateral triangle, in which the side between the centers of the first and second acoustic mirrors is greater than the side between the second and third acoustic mirrors, and the base of the triangle between the centers of the first and third acoustic mirrors is greater than the sides of the first-second acoustic mirrors and the second-third acoustic mirrors, wherein the cross-sectional area of the region of space formed by the flow forming device of the ultrasonic water meter, filled with a moving measured medium, namely the flow region, changes along the central axis, and the change in the cross-sectional area of the flow region does not have a periodicity.

Brief description of the drawings

Fig. 1 shows the external view from the inside of the claimed device for forming the flow of an ultrasonic water meter.

Fig. 2 shows a side view of the claimed device for forming the flow of an ultrasonic water meter.

Fig. 3 shows the external appearance of the product in which the declared technical solution is applied.

Fig. 4 shows a comparison of the regions formed by the flow forming device of the ultrasonic flow meter for measuring the flow rate of liquid of the closest analogue and the claimed device.

Fig. 5 shows the results of the calculation using the finite element method of the velocity field of the measured medium flowing through the flow forming device of the closest analogue and the declared device.

Fig. 6A-6B show graphs of the dependence of the average flow velocity along the central sections of the closest analogue and the claimed device.

Fig. 7A-7B show sections of the velocity field and rotational velocity components in the planes of the propagation trajectory of ultrasonic pulses for the closest analogue and the claimed device.

Fig. 8A-8B show the results of calculating the dispersion of the transit time of ultrasonic pulses for various straight sections of the trajectory for the closest analogue and the claimed device.

Implementation of a utility model

The claimed device for forming the flow of an ultrasonic water meter (Fig. 1) consists of a plastic insert 1, a left ultrasonic sensor 2, a right ultrasonic sensor 3, a first acoustic mirror 4, a second acoustic mirror 5, and a third acoustic mirror 6.

The claimed device is formed by a plastic insert consisting of two parts, three metal acoustic mirrors and housings of two ultrasonic sensors, while the shape of the housings of the ultrasonic sensors differs from each other.

The flow forming device is assembled inside the brass body of the primary transducer of the ultrasonic water meter. The functional purpose of the device is to reform the velocity diagrams of the incoming liquid flow in order to increase the average velocity in the measurement area, reduce the effect of distortion of the incoming liquid flow on the metrological result of measuring the volume flow.

An asymmetric flow region is a region whose cross-sectional area does not change periodically.

Fig. 4 shows examples of symmetrical and asymmetrical flow regions. Under the letter A is shown the region formed by the flow forming device of the ultrasonic flow meter for measuring the flow of liquid Ultrimis UL2.5., where the left and right halves of the region are identical. Under the letter B is shown the region formed by the claimed device, the left and right halves of which are different.

The declared technical result is confirmed by calculations and measurements.

The fluid flow through the device was calculated using the finite element method (Fig. 5).

Fig. 5 shows the results of the finite element calculation of the velocity field of the measured medium flowing through the Ultrimis UL2.5 flow forming device (Letter A) and the patented device (Letter B). The black lines indicate the trajectory of propagation of ultrasonic pulses. The calculation was carried out for a flow rate of 0.1 ^m3 /h.

For each straight section of the trajectory of propagation of ultrasonic pulses, the flight time of the pulses of the ascending and descending flows was calculated using the formulas

,

,

where t _dn , t _up are the flight times of the downward and upward flow pulses, respectively, L is the length of the straight section, c is the speed of sound in water, V is the resulting water flow velocity calculated by the finite element method, α is the angle between the straight section and V.

Next, for each straight section, the difference in the flight time of the ascending and descending ultrasonic pulses is calculated using the formula

Next, the calculated differences in flight times are added together.

From the calculations it follows that the total difference in the flight times of Ultrimis UL2.5 is 6.8 ns. The total difference in the flight times of the patented object is 8.65 ns. Which is 27% higher than that of the prototype, which is an advantage.

To measure pressure losses at the nominal flow rate (2.5 ^m3 /h), excess pressure sensors were placed before and after the model of the patented object. The readings were subtracted taking into account the pressure drop in the measuring pipeline. The measurement result was 0.21 bar. The regulated pressure loss of the prototype is 0.25 bar, which is an advantage.

Fig. 6A-6B show graphs of the dependence of the average flow velocity along the central sections of the prototype (Letter A) and the patented object (Letter B). The calculation was carried out using the finite element method at a flow rate of 0.1 ^m3 /h.

It is evident from the graphs that in the metrologically significant part of the prototype area and the patent object area, the average speed was 0.267 m/s and 0.272 m/s, respectively, which is an advantage.

Fig. 7A and Fig. 7B show sections of the velocity field and rotational velocity components in the planes of the ultrasonic pulse propagation trajectory for the prototype (A) and the patented object (B). The calculation was carried out at a volume flow rate of 0.1 ^m3 /h using the finite element method. The water flow entering the flow region was distorted by a swirler corresponding to GOST ISO 4064-2-2017 at a distance of 0 Du.

From the presented graphs it is evident that the prototype has a change in the average value of the difference in the flight times of ultrasonic pulses under the influence of the swirler of 4.7%, while the patented object has a change of 1%, which is an advantage.

Based on the specified data, the dispersion of the ultrasonic pulse travel time was calculated for different straight sections of the trajectory. The results are shown in Fig. 8A (prototype) and Fig. 8B (patented object).

The sizes of the plastic insert, acoustic mirrors and ultrasonic sensors were selected by the applicant by means of an experimental method through calculations. It is with these sizes that the declared technical results will be achieved.

Claims (1)

A flow shaping device for an ultrasonic water meter comprising a plastic insert consisting of two joined parts with a length of L = 70 mm and an input and output aperture diameter of D = 18 mm, wherein the insert is a generatrix that fixes the positions of three metal acoustic mirrors with overall dimensions of 9.8 mm by 7.8 mm, a thickness of 0.5 mm and a radius of curvature in the plane of the long side of R = 150 mm and two ultrasonic sensors - a left one, with an radiated surface area of Sл = 59 mm ² , a radius of curvature of the spherical radiating surface of Rл = 120 mm, a height of hл = 9 mm and a right one, with an radiated surface area of Sp = 41 mm ² , a radius of curvature of the spherical radiating surface of Rп = 120 mm, a height of hп = 11.4 mm, such that the distance from the center of the radiating surface of the left ultrasonic sensor to the center of the first acoustic mirror is greater than the distance from the center the radiating surface of the right ultrasonic sensor to the center of the third acoustic mirror, and the centers of the first, second and third acoustic mirrors form a non-equilateral triangle, in which the side between the centers of the first and second acoustic mirrors is greater than the side between the second and third acoustic mirrors, and the base of the triangle between the centers of the first and third acoustic mirrors is greater than the sides of the first-second acoustic mirrors and the second-third acoustic mirrors, wherein the cross-sectional area of the region of space formed by the flow forming device of the ultrasonic water meter, filled with a moving measured medium, namely the flow region, changes along the central axis, and the change in the cross-sectional area of the flow region does not have a periodicity.