KR20080048164A - Vortex flowmeter - Google Patents

Abstract

A vortex flowmeter is provided to increase detection performance of a piezoelectric sensor since vortex generated by a vortex generation member varies in pressure widely. A vortex flowmeter includes a body, a pair of connection members, a vortex generation member(21) and a flux sensor(50). The vortex generation member generates vortex inside a pipe by interfering normal flow of fluid introducing into the flowmeter body. The body is arranged between channels so as to temporally store the fluid for changing physical changes of the generated vortex into an electrical signal. The connection members are formed in a cap shape to connect each of a fluid supply unit and a fluid demand unit to the channels formed at both sides of the body, respectively. The flux sensor comprises a piezoelectric sensor inserted into a sensor cap, is installed under the vortex generation member within influence of vortex, and efficiently transmits physical changes to a controller.

Description

Vortex Flowmeter {VORTEX FLOWMETER}

1 is an external perspective view of a vortex flow meter according to an embodiment of the present invention.

Figure 2 is a perspective view showing the arrangement relationship between the vortex generating member and the flow sensor of the vortex flow meter of the present invention.

Figure 3 is an exploded perspective view of the vortex flow meter according to an embodiment of the present invention.

Figure 4 is a longitudinal cross-sectional view of a vortex flow meter according to an embodiment of the present invention.

5 is a partially cutaway perspective view of a vortex flow meter according to an embodiment of the present invention.

6 is a view for explaining the coupling principle of the piezoelectric sensor and the sensor cap configured in the vortex flow meter according to an embodiment of the present invention.

7A to 7E are longitudinal cross-sectional views showing various shapes of the flow sensor part of the vortex flow meter according to the embodiment of the present invention.

8 is a structural diagram of a piezoelectric sensor of the present invention.

Figure 9a so Figure 9e is a view showing the various shapes of the vortex generating member of the present invention.

10 is a block diagram of a control device of the vortex flow meter of the present invention.

* Description of Signs of Major Parts of Drawings *

10: euro 20: torso

21: vortex generating member 30, 40: coupling member

50: flow sensor 51: sensor cap

52: piezoelectric sensor 53: lead wire

The present invention relates to a vortex flow meter, and more particularly, a vortex flow meter which enables accurate flow control by increasing the output sensitivity of an electrical signal according to the physical change of the vortex and at the same time effectively generating the vortex in a fluid flow pipe. It is about.

Generally, there are various types of flowmeters for measuring the amount of fluid flowing in a pipe, but in particular, an ultrasonic flowmeter using a change in the speed of ultrasonic waves by a fluid velocity, and a vortex flowmeter for measuring the flow rate by generating a vortex in the fluid. Is representative.

A pair of ultrasonic transceivers are installed in the pipe so as to alternately transmit and receive ultrasonic flowmeters to calculate the flow rate. For example, an ultrasonic transceiver uses piezoelectric vibrators, such as piezoelectric ceramics, as an electrical energy and a mechanical energy conversion element.

That is, when the ultrasonic transceiver of one side radiates the ultrasonic signal, the ultrasonic transceiver of the other side reaches after a certain time. The ultrasonic transceiver on the other side converts only the transmitted ultrasonic burst signal into an electrical burst signal, and emits the ultrasonic burst signal back to the ultrasonic transceiver on one side by using the electrical burst signal as a trigger signal. After time, one side of the ultrasonic transceiver is reached.

Ultrasonic flowmeters determine the flow rate of a fluid and the flow rate from the flow rate according to the transmission and reception of such an ultrasonic signal.

However, when the ultrasonic flowmeter has a long interval between the ultrasonic wave receiver on the one side and the ultrasonic wave receiver on the other side, or when vortices of various sizes occur in the fluid flow, ultrasonic pulses may be refracted, diffused, or absorbed attenuation changes, thereby causing measurement errors. have. In addition, the ultrasonic flowmeter has a problem in that the configuration is complicated and the manufacturing cost is high.

 On the other hand, the vortex flowmeter using the vortex sensor uses that the Karman swirling flow frequency is proportional to the flow rate of the fluid. For example, when a columnar vortex generator is installed in a pipe, the vortex generator generates a stable and regular vortex due to the flow of fluid.

This vortex occurs due to the separation of the boundary layer between the object and the fluid and is called a carman vortex. In this case, it is well known that the number of vortices (frequency of vortices) generated in unit time on the right side of an object is proportional to the flow velocity of the fluid.

Therefore, when the number of vortices generated in unit time is known, the flow velocity or flow rate of the fluid can be known. That is, the vortex flowmeter generates vortices in the vortex generator to generate vortex signals due to changes in stress, pressure, and the like, and the vortex sensor receives the vortex signals and outputs them as pulse signals.

However, such a vortex flowmeter has a problem that the vortex signal measured when the vortex signal generated from the vortex generator is weak is used only in a minute flow rate band of less than a certain amount.

Therefore, an object of the present invention is to solve the problems of the conventional vortex flow meter as described above, the object of the present invention is to cause the vortex to be effectively generated by the vortex generating member and at the same time of the electrical signal according to the physical change of the vortex The purpose is to provide a vortex flowmeter that allows for accurate flow control by enhancing output sensitivity.

In the vortex flow meter of the present invention for achieving the above object, a flow path is formed to penetrate both sides so that the fluid flows, and when the fluid flows into the vortex, the physical change of the generated vortex is converted into an electrical signal. A body disposed between the flow paths so that the fluid is temporarily stored, and a coupling member formed in a kind of cap form to connect the fluid supply part and the fluid demand part to the flow paths formed on both sides of the body, and the fluid flows into the body. A vortex generating member which interrupts normal flow and generates vortices in the duct, and a piezoelectric sensor is inserted and molded into the sensor cap so as to efficiently transmit the physical change due to the vortex, which is installed within the vortex action range downstream of the vortex generating member. Characterized in that configured to include a flow sensor.

Flow sensor unit of the present invention is characterized in that it comprises a piezoelectric sensor laminated in a plurality of layers built in the sensor cap to output an electrical signal proportional to the flow rate through the alternating pressure of the generated Karman vortex.

The sensor cap of the present invention is characterized in that the lower portion is manufactured in a curved shape inclined at an angle toward the center so that the wing portion is effectively transmitted to the generated vortex to convert the piezoelectric sensor into an electrical signal.

The piezoelectric sensor of the present invention is characterized in that it adopts a three-layer lamination method in which a metal and PZT are configured on both sides thereof, and a plus / minus connection method in which a lead wire is connected to each other and a lead wire is welded to any one minus terminal.

The vortex generating member of the present invention is not limited in shape, and is preferably formed in any one of a quadrangle, a semicircle, a parallelogram, a lozenge, and a triangle.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an external perspective view of a vortex flow meter according to an embodiment of the present invention, Figure 2 is a perspective view showing the arrangement relationship between the vortex generating member and the flow sensor of the vortex flow meter of the present invention, Figure 3 is an embodiment of the present invention Figure 4 is an exploded perspective view of the vortex flow meter according to the present invention, Figure 4 is a longitudinal sectional view of the vortex flow meter according to an embodiment of the present invention, Figure 5 is a partially cutaway perspective view of the vortex flow meter according to an embodiment of the present invention, Figure 6 is an embodiment of the present invention 7A to 7E are cross-sectional views illustrating various shapes of a flow sensor part of a vortex flow meter according to an embodiment of the present invention. FIG. 7A to 7E illustrate a coupling principle of a piezoelectric sensor and a sensing cap. 8 is a structural diagram of the piezoelectric sensor of the present invention, Figures 9a to 9e is a view showing the vortex generating member of various shapes of the present invention, Figure 10 is a configuration diagram of the control device of the vortex flow meter of the present invention.

As shown in FIG. 1, in the vortex flow meter of the present invention, a flow path 10 penetrating both sides is formed so that fluid flows, and when a fluid flows in and vortices are generated, the physical change of the generated vortex is converted into an electrical signal. A fluid supply part (not shown) and a fluid demand part (not shown) are disposed in the trunk 20 disposed between the flow paths 10 so that the fluid is temporarily stored for conversion of the fluid, and the flow paths 10 formed on both sides of the body 20. ) Is composed of a coupling member 30, 40 formed in a kind of cap type to connect each).

As shown in FIGS. 2, 4 and 5, the vortex generating member 21 for generating a vortex in the tube 24 by hindering the normal flow of the introduced fluid in the body 20 of the vortex flowmeter of the present invention. And a flow rate sensor part 50 installed within the vortex action range downstream of the vortex generating member to insert the piezoelectric sensor 52 into the sensor cap 51 so as to efficiently transmit the physical change amount due to the vortex to the controller. do.

The vortex generating member 21 is not limited to a special shape because the vortex may be formed by disturbing the flow of the fluid in the oil tube 24. Vortex generating member 21 according to an embodiment of the present invention is any of a variety of shapes (square, semicircle, parallelogram, rhombus, triangle, etc.) as shown in Figure 9a to 9e on the inner wall of the tube (24) It is arranged vertically in one shape.

In this way, the vortex generated by the vortex generating member 21 disposed and fixed in the tube 24 is kept active within a certain distance from the vortex generating member 21, and thus, Figs. 2, 4 and 5 within this distance. As shown in FIG. 5, the flow sensor 50 is disposed.

On the other hand, the vortex generating member 21 is designed by setting the appropriate thickness because the degree of vortex generation may vary depending on the thickness.

In addition, the flow sensor 50 detects the vortex with the maximum sensitivity and adjusts the distance between the vortex generating member 21 and the flow sensor unit 50 and the number of vortex generating members 21 so as to enable accurate flow rate adjustment. .

As shown in FIG. 6, the flow sensor unit 50 includes a piezoelectric sensor 52 embedded in the sensor cap 51 to output an electrical signal proportional to the flow rate through the alternating pressure of the generated vortex.

As shown in FIG. 6, the sensor cap 51 includes a lead wire 53 connected to the piezoelectric sensor 52, and the piezoelectric sensor 52 and the panel of FIG. 3 through the lead wire 53. 26) electrical connections are made between the printed circuit boards 28 disposed thereon.

The sensor cap 51 has a curved portion (U) at a predetermined angle whose lower surface is recessed toward the center point so that the wing portion at the lower side thereof effectively receives the generated vortex and converts it into an electrical signal at the piezoelectric sensor 52. Manufacture. In other words, in order to obtain sufficient detection sensitivity in the piezoelectric sensor 52, it is advantageous to have a large distortion on the surface, thereby manufacturing the sensor cap 51 as described above.

Various shapes of the sensor cap 51 are shown in FIGS. 7A-7E.

The piezoelectric sensor 52 according to the present embodiment detects a change in the physical energy caused by the vortex generated from the vortex generating member 21 as a change in the electrical signal, and detects the vortex generating frequency in accordance with the number of times of the change. For example, when a force is applied to the polarization direction of the piezoelectric sensor 52, electric charges are generated at both sides, and a potential difference proportional to the magnitude of the applied force is generated.

The piezoelectric sensor 52 is manufactured in consideration of this because the resonant frequency characteristics are different according to the material, material composition ratio, size, etc. The piezoelectric sensor 52 of the present invention is made of metal (M) as shown in FIG. ) And a three-layer lamination method with PZT on both sides and a (+) (-) connection method in which the (-) terminals are connected to each other and the lead wire 53 is welded (W) to any one of the (-) terminals. To improve the eddy current detection effect.

As shown in FIG. 3, the flow sensor unit 50 is fixed in the oil pipe 24 by fastening the panel 26, which is inserted into the housing through the O-ring 25 and covered at the upper portion, with fixing means 27 such as bolts. do.

When the printed circuit board 28 is placed in the body 20, the cover 29 is placed thereon, and the upper surface of the body 20 is closed by fastening the body 20 with the fixing means 31 such as a bolt. The fluid supply part and the fluid demand part are respectively coupled to the holes of the coupling member 30 and 40 fastened to correspond to the flow path 10 through the O-rings 32 and 33.

Therefore, both sides of the body 20 are also closed to prevent leakage when fluid flows in the body 20.

Referring to the operation of the vortex flow meter of the present invention configured as described above are as follows.

A certain amount of fluid is supplied from the fluid supply part to the flowmeter and flows into the oil pipe 24 through the flow path 10.

Therefore, Karman vortices are generated from both sides of the surface of the vortex generating member 21 facing in the flow direction of the fluid through the vortex generating member 21 disposed in the oil pipe 24.

The Karman vortex reaches the flow sensor unit 50 disposed within a certain distance in which the active state is maintained behind the vortex generating member 21 disposed in the fluid flow.

At this time, the alternating stress acting by the Karman vortex is transmitted to the lower portion of the sensor cap 51 of the flow sensor 50. Therefore, the pressure of the vortex transmitted to the lower portion of the sensor cap 51 formed to be bent at an angle to dent greatly changes.

Therefore, after the pressure that is changed by the piezoelectric sensor 52 is easily detected by the piezoelectric sensor 52 and converted into an electric signal by the lower shape of the sensor cap 51, the converted detection signal is fixed through the signal amplifier 60. Amplified by the signal.

The detection signal amplified by the predetermined signal is input to the controller 90 through the detection signal input unit 80 after the noise is removed by the filter 70.

Accordingly, the controller 90 determines the flow rate control value by comparing the already stored flow rate reference value with the current flow rate value, and then inputs the control signal to the fluid supply unit 110 through the control signal output unit 100.

Therefore, the fluid supply unit 110 supplies the flow rate adjusted by the control signal of the control unit 90 to the flow meter 120.

Although the present invention has been described with reference to specific embodiments, the present invention is not limited thereto, and modifications and variations may be made by those skilled in the art without departing from the technical spirit of the present invention.

According to the vortex flow meter according to the present invention as described above has the following excellent effects.

First, it is possible to improve the detection performance of the piezoelectric sensor by making the pressure change of the vortex generated by the vortex generating member in the pipe large.

Second, the piezoelectric sensor for flow rate sensing can be laminated in three layers to improve the sensing performance of the vortex.

Third, by converting the lower surface of the sensor cap into a curved shape at an angle, the generated vortex is effectively transmitted and the conversion performance of the piezoelectric sensor into an electrical signal is improved.

Claims (5)

A flow path 10 penetrating both sides is formed so that the fluid flows, and when the fluid enters and the vortex is generated, the flow path 10 is temporarily stored so that the fluid is temporarily stored for converting the physical change of the generated vortex into an electrical signal. It is composed of a coupling member 30, 40 formed in a kind of cap form so as to connect the fluid supply portion and the fluid demand portion to the body 20 disposed and the flow path 10 formed on both sides of the body 20, In the body 20, the vortex generating member 21 which interrupts the normal flow of the introduced fluid to generate the vortex in the oil pipe 24, and the amount of physical change caused by the vortex is installed within the vortex action range downstream of the vortex generating member. Vortex flow meter, characterized in that it comprises a flow sensor unit 50 is molded by inserting the piezoelectric sensor 52 into the sensor cap 51 so as to efficiently transmit to the control unit. The piezoelectric sensor (52) of claim 1, wherein the flow sensor unit (50) includes a piezoelectric sensor (52) stacked in a plurality of layers embedded in the sensor cap (22) to output an electrical signal proportional to the flow rate through the alternating pressure of the generated vortex. Vortex flow meter comprising a configuration. According to claim 1 or claim 2, wherein the sensor cap 51 is bent portion of the lower surface is inclined at a certain angle so that the vortices are generated efficiently to convert the piezoelectric sensor 52 into an electrical signal A vortex flow meter which is manufactured in a true shape (U), preferably in any one of the shapes of FIGS. 7A to 7E. The piezoelectric sensor (52) according to claim 2, wherein the piezoelectric sensor (52) is constituted by a three-layer lamination method in which a metal (M) and PZT are formed at both sides thereof, and the (-) terminals are connected to each other and the lead wire 53 is connected to one of the ( -) Vortex flowmeter which adopts (+) (-) connection method welded to terminal (W). The vortex flow meter according to claim 1, wherein the vortex generating member (21) is not limited in shape, and is preferably formed in any one of the shapes of FIGS. 9A to 9E.

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