KR101010055B1 - Disk flow meter and its control method - Google Patents

Abstract

The present invention provides a disk flow meter and a control method thereof, comprising: a flow meter body formed in a pipe through which a fluid flows; A disk installed in the flowmeter body such that hydrodynamic forces act when the fluid flows; A disk shaft connected by said disk and disk arm; A strain measuring device for measuring strain transmitted to the disk axis; A disc angle adjusting device for adjusting the inclination angle of the disc with respect to the flow direction; Flow rate detection device for converting the strain measured by the strain measuring device to the flow rate through the torque and the geometric information about the disk, comprising a disk that can adjust the inclination of the flow direction in the pipe and the fluid The flow rate can be calculated by detecting the torque generated in the disk shaft as a strain gauge when it flows.

Disc, Flow Meter, Tubing, Slope, Strain, Torque

Description

Disk flow meter and its control method

The present invention relates to the detection of the flow rate of the fluid flowing in the pipe, in particular to install a disk that can adjust the inclination of the flow direction in the pipe and to calculate the flow rate by detecting the torque generated in the disk shaft when the fluid flows with a strain gauge Disc flow meter and a control method thereof that are suitable for.

In general, a flow meter is a device for measuring the flow rate of a fluid flowing in a pipe.

Therefore, in the conventional flow meter using a differential pressure measurement method, a method of measuring flow rates by installing an orifice plate or a venturi of a constant size in a pipe and measuring a differential pressure has been commonly used.

However, the disadvantage of this prior art has to be provided with an orifice (or venturi) and a differential pressure gauge having a different measuring range according to the flow rate range, there is a disadvantage that a pressure hole must be drilled in the pipe to measure the pressure.

Therefore, the present invention has been proposed to solve the conventional problems as described above, and an object of the present invention is to install a disk that can adjust the inclination of the flow direction in the pipe and the torque generated on the disk shaft when the fluid flows SUMMARY OF THE INVENTION An object of the present invention is to provide a disk flowmeter and a control method thereof, which can detect a strain gauge and calculate a flow rate.

1 is a cross-sectional view showing an upper portion of a disk flow meter including a flow rate detection apparatus according to an embodiment of the present invention, Figure 2 is a cross-sectional view showing the front of the disk flow meter in Figure 1, Figure 3 is the strain of Figure 1 4 is a perspective view illustrating a position at which a strain gage is attached to a measuring device, and FIG. 4 is a cross-sectional view illustrating a position at which a strain gage is attached according to another embodiment of the present invention, and FIG. 5 is a disc angle adjusting device in FIG. 1. 6 is a cross-sectional view of the flow rate detecting apparatus of FIG. 1.

As shown therein, the flow meter body 10 formed in the pipe through which the fluid flows; A disk 20 installed in the flowmeter body 10 so that hydrodynamic force acts when the fluid flows; A disk shaft (40) connected by the disk (20) and the disk arm (30); A strain measuring device (50) for measuring strain transmitted to the disk shaft (40); A disc angle adjusting device (60) for adjusting the inclination angle of the disc (20) with respect to the flow direction; And a flow rate detection device 70 for converting the strain measured by the strain measurement device 50 into a flow rate through the torque and the geometric information about the disk 20.

The disk shaft 40 is sealed due to the waterproofing of the strain gauges 51, 52, 53, and 54 installed on the disk shaft 40 and the wires drawn out of the flowmeter body 10. A portion of the disc shaft 40 is provided as a hollow shaft to minimize the problem.

The strain measuring device 50 is characterized in that it comprises two or four strain gauges (51, 52, 53, 54) to measure the torque transmitted to the disk shaft (40).

The strain measuring device 50 is a Wheatstone in the form of a half or full bridge to detect a change in resistance caused by deformation of four or two strain gauges 51, 52, 53, and 54. It characterized in that it comprises a bridge (Wheatstone Bridge) (not shown in the figure).

The strain gauges 51, 52, 53, 54 are attached to the inside of the disk arm 30 or between the disk arm 30 and the disk shaft 40 so as not to come into contact with the fluid.

The strain measuring device 50 has a wire connecting the strain gauges 51, 52, 53, and 54 to the Wheatstone bridge along the inside of the disk shaft 40 along the flow meter body 10. It is characterized in that it is arranged to come out of.

The disc angle adjusting device 60 includes a lever 63, a spring 64, an angle adjusting pin 65, and a handle 66 to adjust the angle of the disc 20 according to the flow rate measuring range. Characterized in that configured.

The disk angle adjusting device 60, characterized in that configured using a worm and worm gear or bevel gear.

The flow rate detection device (70) includes: a voltage generator (71) for generating and amplifying a voltage proportional to the strain measured by the strain measurement device (50); An analog / digital converter 72 for converting an analog voltage generated by the voltage generator 71 into a digital signal; A torque calculator 73 for calculating torque Tq generated in the disk shaft 40 by a hydrodynamic force applied to the disk 20 by using the digital signal of the analog / digital converter 72; ; And a flow rate calculator 74 that calculates a flow rate using the torque Tq calculated by the torque calculator 73, the geometric information of the flow meter, and the hydrodynamic torque coefficient.

The voltage generator 71 includes an amplifier (not shown) and an anti-aliasing filter (not shown) for amplifying a voltage signal generated from a Wheatstone bridge. Characterized in that configured.

The torque calculation unit 73 calculates a hydrodynamic torque acting on the disk 20 by using the digital signal of the analog / digital conversion unit 72 and information of shear modulus of elasticity, polar moment of inertia, inner diameter, and outer diameter. It is characterized by calculating.

The flow rate calculator 74 calculates the flow rate using the torque calculated by the torque calculator 73 and the previously stored disc diameter, density, disc angle, hydrodynamic torque coefficient, and flowmeter cross-sectional area information.

7 is a flowchart illustrating a control method of a disk flow meter according to an embodiment of the present invention.

As shown therein, a first step (ST1) of generating and amplifying an analog voltage proportional to the strain measured by the strain measuring device 50 in the disk flow meter; A second step ST2 of converting the analog voltage amplified in the first step into a digital signal; A third step (ST3) of calculating the torque (Tq) generated on the disc shaft (40) by the hydrodynamic force acting on the disc (20) by using the digital signal of the second step; And a fourth step (ST4) for calculating the flow rate using the torque Tq calculated in the third step, the geometric information of the flow meter, and the hydrodynamic torque coefficient.

The third step is to calculate the hydrodynamic torque acting on the disk 20 by using the digital signal of the second step and the information of the shear modulus, polar moment of inertia, inner diameter, outer diameter.

The fourth step is characterized in that the flow rate is calculated using the torque calculated in the third step and previously stored disk diameter, density, disk angle, hydrodynamic torque coefficient and flow meter cross-sectional information.

Disc flow meter and control method thereof according to the present invention has the effect of calculating the flow rate by installing a disc that can adjust the inclination of the flow direction in the pipe and the strain generated by the strain gauge when the fluid flows Will be.

In addition, the present invention measures the hydrodynamic torque acting on the disk shaft and calculates the direct flow rate so that the differential pressure flow meter and the pressure hole do not need to be drilled in the pipe.

In addition, the present invention can amplify the measurement torque by adjusting the disk angle with respect to the flow direction, it is possible to measure a wide range of flow rate with one device.

Furthermore, the present invention can be applied to various fluids such as a fluid mixed with particles since the torque measuring sensor part does not contact the fluid.

Referring to the preferred embodiment of the disk flow meter and the control method according to the present invention configured as described above in detail with reference to the accompanying drawings as follows. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to intention or precedent of a user or an operator, and thus, the meaning of each term should be interpreted based on the contents throughout the present specification. will be.

First, the present invention is to install a disk that can adjust the inclination with respect to the flow direction in the pipe and to calculate the flow rate by detecting the torque generated in the disk shaft when the fluid flows by the strain gauge.

1 is a cross-sectional view showing an upper portion of a disk flow meter including a flow rate detection apparatus according to an embodiment of the present invention, Figure 2 is a cross-sectional view showing the front of the disk flow meter in Figure 1, Figure 3 is the strain of Figure 1 4 is a perspective view illustrating a position at which a strain gage is attached to a measuring device, and FIG. 4 is a cross-sectional view illustrating a position at which a strain gage is attached according to another embodiment of the present invention, and FIG. 5 is a disc angle adjusting device in FIG. 1. 6 is a cross-sectional view of the flow rate detecting apparatus of FIG. 1.

1 to 6, the disk flow meter according to the present invention is a flow meter body 10, disk 20, disk arm 30, disk shaft 40, strain measuring device 50, disk angle adjusting device 60 and the flow rate detection device 70 are included.

Specifically, a fluid tube through which a fluid flows is formed inside the flow meter body 10. At a certain point of the flowmeter body 10, a disk 20 to which a force of fluid is applied is formed.

The disk 20 is fixed to the disk shaft 40 by the disk arm 30, and the disk arm 30 is attached to the disk shaft 40 rotatably fitted to one side of the flowmeter body 10.

The flow meter of the present invention may be installed such that the disk shaft 40 is parallel to the direction of gravity as shown in FIG. 2 to minimize the torque transmitted by the weight of the disk 20 to the disk shaft 40.

Strain measuring device 50 is formed by strain gauges 51, 52, 53, 54 and Wheatstone Bridge (not shown) attached to the disk. The output of the strain gauges 51, 52, 53, 54 is transformed into a voltage proportional to the strain generated in the disk shaft 40 via a Wheatstone Bridge (not shown) in the form of a full bridge.

At this time, the strain gauges (51, 52, 53, 54) is made of a hollow portion of the disk shaft 40 to minimize the sealing problem that may be caused by the waterproof of the strain gauge and the wire drawn out of the flowmeter body It is attached inside the hollow surface.

The strain gauges 51, 52, 53, 54 can be attached between the disk arm 30 and the disk shaft 40, as shown in FIG. 4.

In addition, the voltage proportional to the strain may be provided by the output of the Wheatstone Bridge (not shown) in the form of a half bridge through the strain gauges (51, 52) or strain gauges (53, 54).

At this time, the wires connecting the strain gauges (51, 52, 53, 54) and the Wheatstone Bridge are arranged to extend out of the flowmeter body along the inside of the disk axis.

The disc angle adjusting device 60 is formed to be connected to the disc shaft 40 and attached to one side of the flow meter body 10.

As shown in FIG. 5, the disc angle adjusting device 60 includes a protractor 61, an angle indicating needle 62, a lever 63, a spring 64, and an angle so as to adjust the disc angle according to the flow measurement range. Adjustment pin 65 and handle 66. Holding the handle 66 of the disk angle adjusting device 60 and pressing the lever 63, the spring 64 and the angle adjusting pin 65 can be pressed to adjust the angle of the disk. The adjusted disc angle is indicated by the protractor 61 and the angle indicating needle 62.

The change of the disc angle may be provided by an angle adjusting device (not shown) using a worm and a worm gear, an angle adjusting device using a bevel gear, etc. in addition to the disk angle adjusting device 60 described above.

Therefore, when fluid flows inside the flowmeter body 10, a force by the fluid acts on the disk 20, and strain causes the disk shaft 40 to be caused by this force. This strain is converted into a voltage proportional to the strain through the strain measuring device 50. The measured strain is converted to torque in the flow rate detection device 70 and then detected as a flow rate by inputting the flowmeter geometric information and hydrodynamic torque coefficient. The flow rate detection device 70 will be described in more detail with reference to FIGS. 6 and 7.

FIG. 6 is a block diagram illustrating a flow rate detecting apparatus in FIG. 1, and FIG. 7 is a flowchart illustrating a method of controlling a disk flow meter according to an embodiment of the present invention.

Thus, the flow rate detection device 70 includes a voltage generator 71, an analog / digital converter 72, a torque calculator 73, and a flow rate calculator 74.

In detail, the voltage proportional to the strain generated through the strain measuring device 50 is converted into a voltage capable of analog / digital conversion through the voltage generator 71 formed of an amplifier, an anti-aliasing filter, or the like (ST1).

The voltage generated by the voltage generator 71 is applied to the analog / digital converter 72 and converted into a digital signal (ST2).

The torque calculating unit 73 calculates the torque Tq generated on the disc shaft 40 by the hydrodynamic force applied to the disc using the digital signal of the analog / digital converting unit 72 (ST3).

The flow rate calculator 74 calculates the flow rate using the torque Tq calculated by the torque calculator 73, the geometric information of the flow meter, and the hydrodynamic torque coefficient (ST4).

The operating principle of the above-described flow rate detection device 70 will be described with reference to FIGS. 1 and 6.

1 and 6, when fluid starts to flow from the front end of the flowmeter body 10, drag due to flow occurs in the disk 20. Since one side of the disc shaft 40 is fixed by the disc angle adjusting device 60, torque is generated in the disc shaft 40. The torque generated on the disk shaft 40 acts on the disk shaft 40 via the strain measuring device 50 attached to the disk shaft 40, the voltage generator 71, and the analog / digital converter 72. It is transformed into a digital voltage signal proportional to the strain.

The digitally converted voltage signal is calculated as the torque Tq through the torque calculator 73. At this time, the voltage signal is converted into a torque Tq using information such as shear modulus, polar moment of inertia, inner diameter, and outer diameter.

), 디스크 각도(

), 유체역학적 토크 계수(

), 유량계 단면적(A)과 토크 산출부(73)에서 산출 된 토크(Tq)를 이용하여 다음의 수학식 1과 같이 유량을 연산한다.The flow rate calculator 74 stores the disc diameter D and the density (

), Disc angle (

), Hydrodynamic torque factor (

), Using the flow meter cross-sectional area (A) and the torque (Tq) calculated by the torque calculating unit 73 calculates the flow rate as shown in the following equation (1).

)는 디스크 각도(

)의 함수로서 실험 또는 해석적으로 산출할 수 있다.Hydrodynamic torque coefficient of Equation 1

) Is the disc angle (

Can be calculated experimentally or analytically as a function of

)를 키우면 커지므로 유량 범위에 따라 디스크 각도(

)를 조절할 수 있게 되면 광범위한 유량 범위에서 유량 검출이 가능해 진다.As shown in Equation 1, the flow rate is proportional to the measured hydrodynamic torque Tq, and the hydrodynamic torque Tq is represented by the disk angle (as shown in FIG. 2).

) Increases as the disc angle changes depending on the flow rate range.

) Can be used to detect flow over a wide range of flow rates.

)를 조절할 수 있으므로 토크(Tq)를 변화시켜 광범위한 유량 측정 범위에서 유량을 검출할 수 있다.The above flow rate calculation method detects the flow rate using only the torque acting on the disc shaft 40 and does not need to drill pressure holes in the pipe like a differential pressure flow meter. In addition, in the case of a differential pressure flow meter, there is a disadvantage in that the orifice (or venturi) size and the differential pressure gauge have to be changed according to the flow rate range, whereas in the present invention, the disc angle (

), The torque (Tq) can be varied to detect the flow rate over a wide range of flow measurement ranges.

Thus, the present invention is to install a disk that can adjust the inclination of the flow direction in the pipe and to calculate the flow rate by detecting the torque generated in the disk shaft when the fluid flows.

Although the present invention has been described in more detail with reference to the examples, the present invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

1 is a cross-sectional view showing an upper portion of a disk flow meter including a flow rate detection device according to an embodiment of the present invention.

2 is a cross-sectional view of the front of the disk flow meter in FIG.

FIG. 3 is a perspective view illustrating a position at which a strain gauge is attached in the strain measuring device of FIG. 1.

Figure 4 is a cross-sectional view for explaining the position where the strain gauge is attached according to another embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating the disc angle adjusting device in FIG. 1.

FIG. 6 is a block diagram illustrating a flow rate detecting device in FIG. 1.

7 is a flowchart illustrating a control method of a disk flow meter according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: flowmeter body

20: disk

30: disk arm

40: disc axis

50: strain measuring device

51, 52, 53, 54: strain gauge

60: disc angle adjustment device

61: protractor

62: angle indicating needle

63: lever

64: spring

65: angle adjusting pin

66: handle

70: flow rate detection device

71: voltage generator

72: analog / digital converter

73: torque calculation unit

74: flow rate calculation unit

Claims (15)

A flow meter body formed in the pipe through which the fluid flows; A disk installed in the flowmeter body such that hydrodynamic forces act when the fluid flows; A disk shaft connected by said disk and disk arm; A strain measuring device for measuring strain transmitted to the disk axis; A disc angle adjusting device for adjusting the inclination angle of the disc with respect to the flow direction; A flow rate detecting device for converting the strain measured by the strain measuring device into a flow rate through torque and geometric information about the disk; Consists of including, The disc axis, And a portion of the disk shaft provided as a hollow shaft so as to minimize the sealing problem that may be caused by the waterproofing of the strain gauge installed on the disk shaft and the wires drawn out of the flowmeter body. delete The method according to claim 1, The strain measuring device, And two or four strain gauges to measure the torque transmitted to the disk shaft. The method according to claim 1, The strain measuring device, A disk flow meter comprising four or two strain gauges including a Wheatstone bridge in the form of a half or full bridge to detect resistance changes caused by deformation. The method according to claim 4, The strain gauge, And a disk flow meter attached to the inside of the disk arm or between the disk arm and the disk shaft so as not to come into contact with the fluid. The method according to claim 4, The strain measuring device, And a wire connecting the strain gauge and the Wheatstone bridge to the outside of the flow meter body along the inside of the disc shaft. The method according to claim 1, The disc angle adjusting device, Disc flow meter comprising a lever, a spring, an angle adjusting pin and a handle to adjust the angle of the disk according to the flow measurement range. The method according to claim 1, The disc angle adjusting device, Disc flow meter, characterized in that configured using a worm and worm gear or bevel gear. The method according to claim 1, The flow rate detection device, A voltage generator for generating and amplifying a voltage proportional to the strain measured by the strain measuring device; An analog / digital converter converting the analog voltage generated by the voltage generator into a digital signal; A torque calculating unit that calculates torque generated on the disk shaft by a hydrodynamic force applied to the disk by using the digital signal of the analog / digital converter; A flow rate calculator for calculating a flow rate using the torque calculated by the torque calculator, geometric information of the flow meter, and a hydrodynamic torque coefficient; Disc flow meter comprising a. The method according to claim 9, The voltage generator, A disk flow meter comprising an amplifier and an antialiasing filter for amplifying a voltage signal generated from a Wheatstone bridge. The method according to claim 9, The torque calculation unit, And a hydrodynamic torque acting on the disk by using the digital signal of the analog / digital converter and information of the shear modulus, polar moment of inertia, inner diameter, and outer diameter. The method according to claim 9, The flow rate calculation unit, And a flow rate is calculated using the torque calculated by the torque calculating unit and the previously stored disc diameter, density, disc angle, hydrodynamic torque coefficient, and flow meter cross-sectional area information. delete delete delete

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