Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
  • G01F1/66—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters
  • G01F1/662—Constructional details

Definitions

• the invention relates to systems for equalizing the flow of fluid in the flow of the flowmeters or in pipelines at the inlet of flowmeters for measuring the volumetric flow rate of fluids.
• Known ultrasonic flow meter consisting of a straight-through span pipeline with a diameter of D and a length L, inlet and outlet chambers connected to the pipeline by means of a confuser and a diffuser, the first and second electro-acoustic transducers located in the chambers and associated with measuring unit.
• the angle of inclination of the generatrix of the diffuser to the axis of the measuring channel is selected in the range of 40-50 °.
• a disadvantage of the known system is its complexity, due to the presence in the flow part of the measuring channel. This channel must be fixed in a certain way inside the flow part of the flow meter. Such fastening is carried out by means of special fasteners fastening the channel to the walls of the flowing part.
• a disadvantage of the known flow meter is its lack of accuracy, because fasteners that secure the channel to the walls of the flowmeter part of the flowmeter will create resistance to flow and cause local flow disturbances.
• the technical problem achieved by the invention is to simplify the design of the device and increase the degree of alignment of the flow.
• each sensor is connected to the measuring unit according to the invention between the sensors an insert tube is installed in the flowing part, the inner section of which is made in the form of an equilateral polygon with rounded corners, the section of the insert tube in the direction from the first sensor to the second it is made tapering, on each end side of the tube-liner in its lower part there are shelves facing outward to a nearby sensor, the inner cavity of the tube-liner forms a measurement zone, the body of each sensor has a streamlined shape that gradually expands in the direction to the measurement zone, the sensors are installed symmetrically with respect to the insert tube. It is advisable that the housing of each sensor was made in the form of a dome.
• each shelf facing the measurement zone be made with a slope facing the nearby sensor.
• each sensor was made of a material that transmits sound radiation.
• the housing of each sensor should be made of glass-filled plastic.
• the radiating element of each sensor may be a piezoelectric element.
• each sensor with its upper part is connected with the housing of the flowing part.
• the inventive device implements the formation of a fluid flow with the required characteristics, allowing to further ensure the required metrological accuracy of the ultrasonic flow meter
• acoustic radiation sensors facing towards each other are installed at a distance from each other.
• a tube is installed between the sensors in the flow part of the flowmeter — an insert, into which a flow is directed, the flow rate of which must be measured.
• the internal cavity of the tube - liner forms a measurement zone. Measurement area - the area between two sensors.
• the tube is a liner that provides flow formation with the required parameters.
• the cross-section of the insert tube has the shape of an equilateral polygon with rounded corners (for example, a rhombus or square) - this allows you to distribute the flow inhomogeneities in the corners, as well as to smooth the velocity diagram and make it more symmetrical and homogeneous. Turbulent zones are scattered along the corners of an equilateral polygon, leaving a stream with a aligned velocity diagram in the sensing zone (in the center).
• the cross section of the liner tube in the direction from the sensor installed at the entrance to the measurement zone to the sensor installed at the output of the measurement zone decreases, i.e. there is a narrowing necessary to maintain the flow rate over the cross section of the tube - liner. Due to this shape of the insert tube, the flow enters the measurement zone through a channel with a uniformly narrowing cross section - thereby equalizing the velocity plot, and also increasing the flow velocity in the flow part, which in turn increases the accuracy of measurements.
• the constriction parameters are determined by calculation and will depend on the geometry of the flow part of the flow meter and the geometry of the inner cavity of the insert tube.
• the housing of each sensor designed to accommodate a radiating element, for example, a piezoelectric element, has a streamlined shape that gradually expands towards the measurement zone (dome shape), thereby ensuring uniform flow around the sensor to the left, right, and bottom, while preventing flow breaks. When flowing around the sensor, redistribution of speeds occurs and a more uniform flow enters the measurement zone.
• the sensors are installed symmetrically (the goal of unifying the elements used is achieved, and the ability to work in reverse mode is also ensured - in the opposite direction).
• the housing of the sensor installed at the entrance to the measurement zone also serves as an element for narrowing the flow at the entrance to the measurement zone (since the sensor housing is installed in the flow part of the flow meter directly at the entrance to the measurement zone and occupies a certain volume in the flow part) .
• Narrowing the flow at the entrance to the measurement zone allows you to increase the flow rate at the entrance to the measurement zone and, thereby, improve the accuracy of the measurement.
• Symmetrical 95, the location of the second sensor allows the flowmeter to work on the reverse (in the opposite direction).
• each sensor makes it possible to ensure the required measurement accuracy even if the flowmeter is installed directly after the elbow (pipe bending 90 °). In this case, the flow is “pressed” to the side
• the shelves which are part of the insert tube, contribute to uniformly accelerated flow around the sensor and uniform distribution of speed at the entrance to the measurement zone, the shadow decreases - the zone of low speeds after flowing around the sensor case due to the fact that after the shelves the flow is directed upward and accelerated.
• the inner surface of each shelf is made with
• the sensor housing is made of a material that transmits radiation (sound),
• 1 15 for example, from glass-filled plastic.
• a radiating element for example, a piezoelectric element, which is most common in ultrasonic flow meters, is installed inside the sensor housing.
• the inventive device provides an allowable pressure drop from the entrance to the measurement zone to the exit from the measurement zone. According to EN1434 - ⁇ P must not be
• the inventive device provides accuracy within ⁇ 1%, which is higher than in existing designs of ultrasonic flow meters that measure flow rate in pipelines.
• the inventive ultrasonic flow meter measures the flow rate based on the measurement 125 of the propagation time of pulses of ultrasonic vibrations through a moving fluid.
• the difference between the propagation times of ultrasonic pulses in the forward and reverse directions relative to fluid motion is proportional to its flow rate.
• the movement of the liquid causes a change in the time difference between the complete propagation of ultrasonic signals along the flow and against it.
• the propagation velocity of an ultrasonic pulse in a fluid filling a pipeline is the sum of the velocities of ultrasound in a stationary fluid and
• ultrasonic flow meter provides high measurement accuracy due to the fact that the plot of the flow rates in each section of the tube insert is maximally aligned. All disturbances are smoothed out as much as possible,
• FIG. 1 shows a longitudinal section of the inventive flow meter - side view.
• FIG. 2 shows a longitudinal section of the inventive flow meter - top view.
• FIG. 3 shows a longitudinal section of an insert tube.
• FIG. 4 shows a cross section of a liner
• FIG. 5 shows a General view of the tube - liner.
• the inventive ultrasonic flow meter contains a rectilinear flowing part 1 — a pipeline, the first and second electro-acoustic sensors (not shown in the drawings), placed in the respective housings 2 and 3, installed inside the flowing part 1 at a distance from each other. Sensors made
• the working element of the sensors is a piezoelectric element.
• an insertion tube 4 the inner section of which is made in the form of a square with rounded corners.
• the section of the liner in the direction from the first sensor to the second is made tapering.
• On each end side of the tube - liner in its lower part is made
• each sensor has a streamlined shape that gradually expands towards the measurement zone, namely: each housing 2,3 is made in the form of a dome.
• the sensors are installed symmetrically with respect to the insert tube 4.
• each sensor 160 facing the measurement zone 6 is made with a slope facing towards a nearby sensor so that the flow flows smoothly from a wider zone to a narrower - measurement zone to reduce flow disturbances.
• the body 2.3 of each sensor is made of a material that transmits sound radiation, namely: glass-filled plastic - polyethersulfone (PES) Ultrason® E G6. 165
• the body 2.3 of each sensor is connected with its upper part to the body of the flowing part.
• the inventive ultrasonic flow meter measures the flow based on measuring the propagation time of the pulses of ultrasonic vibrations through a moving fluid from the first sensor to the second. The difference between the times 170 of the propagation of ultrasonic pulses in the forward and reverse directions relative to the motion of the liquid is proportional to its flow rate.
• the excitation of ultrasonic vibrations is carried out by piezoelectric transducers located inside the sensor housing.

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• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Fluid Mechanics (AREA)
• General Physics & Mathematics (AREA)
• Measuring Volume Flow (AREA)

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Citations (5)

• 2012
  • 2012-04-17 RU RU2012115330/28A patent/RU2502054C1/ru active IP Right Revival
• 2013
  • 2013-01-14 WO PCT/RU2013/000026 patent/WO2013157990A1/fr not_active Ceased

Patent Citations (5)

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