KR20070102179A - Flow meter using ultrasonic-sensor - Google Patents

Abstract

A flow meter using an ultrasonic-sensor is provided to be easily attached/detached to/from a pipe by having a belt for fastening a clamp, and an attaching unit of which a part is a magnet. A flow meter using an ultrasonic-sensor includes a level sensor(40), first and second flux sensors(50,60), a signal outputting device, a signal selecting device, and a controlling device. The level sensor(40) detects the level of fluid flowing through a pipe(10). The first and second flux sensors(50,60) detect the flux of fluid flowing through the pipe(10). The signal outputting device generates an electric signal of a predetermined frequency. The signal selecting device outputs the electric signal to any one among the level sensor(40), the first flux sensor(50), and the second flux sensor(60), and is applied with the signal from any one among the level sensor(40), the first flux sensor(50), and the second flux sensor(60). The controlling device controls the switching operation of the signal selecting device, outputs a trigger signal for operating the signal outputting device so that the level sensor(40), the first flux sensor(50), and the second flux sensor(60) generate ultrasonic waves, calculates the level and flux of fluid through the pipe(10) based on the signal inputted from the signal selecting device, and calculates a flow based on the calculated level and flux.

Description

Flow meter using ultrasonic sensor {flow meter using ultrasonic-sensor}

1 is a perspective view schematically showing a part of an exterior of a flow measuring apparatus using an ultrasonic sensor according to an embodiment of the present invention;

Figure 2a is a schematic cross-sectional view of Figure 1 for explaining the water level measurement process by the flow rate measuring apparatus using the ultrasonic sensor according to the present invention,

FIG. 2B is a graph showing a signal waveform according to the water level measurement result of FIG. 2A;

Figure 3a is a schematic cross-sectional view of Figure 1 for explaining the flow rate measurement process by the flow rate measuring apparatus using the ultrasonic sensor according to the present invention,

3B is a graph showing a signal waveform according to the flow rate measurement result of FIG. 3A;

4 is an electrical block diagram of a flow measurement apparatus using an ultrasonic sensor according to an embodiment of the present invention.

*** Explanation of symbols for the main parts of the drawing ***

10: Tubing 11: Pipe Wall

20: clamp 21: belt

22, 23: fixing bolt 24: sensor support

25: holder 26: guide hole

30: guide rail 40: water level sensor

50: first flow rate sensor 60: second flow rate sensor

41, 51, 61: cable 43, 53, 63: connector

70: attachment hole 80: fluid

100: flow rate measuring device 110: control unit

120: display unit 130: key input unit

140: power supply unit 151: sensor selection unit

153: pulse selector 155: input selector

161: first pulse generator 163: second pulse generator

171: First Preamplifier 173: Second Preamplifier

180: trigger 191: noise canceller

193: amplifier 195: ADC

The present invention relates to a flow rate measuring apparatus using an ultrasonic sensor, in particular, in attaching an ultrasonic sensor for measuring the water level and flow rate of the pipe to the outer wall of the pipe is easy to attach and flow rate based on the water level and flow rate measured by the ultrasonic sensor It relates to a flow rate measuring device using an ultrasonic sensor to measure the.

There are many types of flow measuring devices according to the purpose of measuring the flow rate, the type of fluid to be measured and the required flow measuring accuracy. An electromagnetic flow meter, a turbine flow meter, a vortex flow meter, a positive displacement flow meter, an ultrasonic flow meter, and the like. .

Here, the ultrasonic flow rate measuring device, in particular, the measurement principle is a time difference method, the two ultrasonic sensors attached to the outer wall of the pipe respectively emits ultrasonic waves in the forward and reverse directions of the fluid, respectively, and the difference in the return time of the received echoes, respectively It is a method of measuring the flow rate based on the flow rate and deriving the flow rate from the measured flow rate and the pipe diameter. It was first developed in the 1920s and has shown a lot of technical advances with the development of electronic technology.

However, according to the above-described time difference ultrasonic flow rate measuring apparatus, the flow rate can be easily measured and portable by simply attaching the ultrasonic sensor to the outer wall of the pipe, while the fluid flows through the pipe without the full water level. In other words, when the water level is not constant, there was a problem that the measured flow rate has a large error from the actual condition.

The present invention has been made in order to solve the above-described problems, by providing an ultrasonic sensor for measuring the water level separately from the two ultrasonic sensors for measuring the flow rate, an ultrasonic sensor for measuring the flow rate corresponding to the fluctuations in the water level of the pipe The purpose is to provide a flow rate measuring apparatus used.

Flow rate measuring apparatus using the ultrasonic sensor of the present invention to achieve the above object is a water level sensor for detecting the level of the fluid flowing through the pipe; A first flow rate sensor and a second flow rate sensor for detecting a flow rate of the fluid flowing through the pipe; Signal output means for generating an electrical signal having a predetermined frequency; Selecting a signal that outputs the electrical signal to any one of the water level sensor, the first flow rate sensor and the second flow rate sensor, and receives a signal from any one of the water level sensor, the first flow rate sensor and the second flow rate sensor Controlling a switching operation of the means and the signal selection means, outputting a trigger signal for operating the signal output means to cause the water level sensor, the first flow rate sensor or the second flow rate sensor to emit ultrasonic waves, and the signal selection means It provides a flow rate measuring device using an ultrasonic sensor comprising a control means for calculating the water level and the flow rate of the fluid flowing through the pipe based on the signal received from the, and calculates the flow rate based on the water level and the flow rate.

Hereinafter, a flow rate measuring apparatus using an ultrasonic sensor according to a preferred embodiment of the present invention with reference to the accompanying drawings will be described in detail.

1 is a perspective view schematically illustrating a part of an exterior of a flow measuring apparatus using an ultrasonic sensor according to an exemplary embodiment of the present disclosure.

As shown in FIG. 1, the flow rate measuring device according to the present invention includes a water level sensor 40 that largely detects a level of a fluid flowing through a pipe 10; An attachment hole 70 attached to the lower position of the pipe 10 with the water level sensor 40 mounted thereon; A first clamp 20 fixed to a lower position of the pipe 10 with a first flow rate sensor 50 detecting a flow rate; The second clamp 90, the first clamp 20, and the second clamp 90 fixed to the lower portion of the pipe 10 which is symmetrical with the first clamp 20 with the second flow rate sensor 60 mounted thereon This includes a guide rail 30 that guides the flow of the second clamp 90.

In the above-described configuration, the first flow rate sensor 50 and the second flow rate sensor 60 may be attached to the side of the pipe when the water level is more than half of the pipe 10 constantly.

Next, the clamp 20 includes a sensor support 24 for supporting the first flow rate sensor 50; A hole is formed in the center side to which the sensor support member 24 is fitted, and one end of the guide rail 30 is fixed between the two holes, and a fixing bolt for fixing the sensor support member 24 inserted into the hole on the upper surface thereof. A fixed base 25 in which 22 is formed; It comprises a belt 21 for fastening the fixing stand 25 to the pipe (10).

Next, the second clamp 90 is a belt 91 corresponding to the belt 21, the fixing bolt 22, the sensor support 24 and the fixing table 25, which are the components of the first clamp 20, respectively, A fixing bolt 92, a sensor support 94, and a fixing table 95; It comprises two guide holes (96) through which the guide rail (30) passes between the amount of holes in which the sensor support (94) is fitted. In particular, the fixing bolt 93 for fixing the second clamp 90 at the appropriate point of the guide rail 30 is formed in the upper surface of the fixing table (95).

Next, the guide rail 30 is preferably engraved with a scale indicating the distance between the first clamp 20 and the second clamp 90.

Next, the location of the attachment port 70, that is, the portion in contact with the outer wall of the pipe 10 is preferably made of a magnet. Alternatively, the attachment port 70 may be welded to the pipe 10 to permanently fix the water level sensor 40 to the pipe 10.

Next, the water level sensor 40 is an ultrasonic sensor and a connector 43 is formed on one surface thereof, where the connector 43 is connected to a cable 41 through which an electric signal flows. Similarly, the flow rate sensors 50 and 60 are also ultrasonic sensors, and connectors 53 and 63 are formed, respectively, and the connectors 53 and 63 are also connected to the cables 51 and 61, respectively. In particular, the cables 41, 51, 61 are preferably coaxial cables, and each of the connectors 43, 53, 63 connected thereto is a BNC or Lemo type and is detachable from each of the cables 41, 51, 61. desirable.

In the drawings, reference numeral 11 denotes a pipe wall of the pipe 10. Although not shown, the connectors 43, 53, and 63 supply electrical signals to the sensors 40, 50, and 60, and each sensor ( 40, 50, 60 is connected to the electric device for measuring the flow rate based on the signal sensed, the electrical configuration of the electric device will be described in detail in FIG.

FIG. 2A is a schematic cross-sectional view of FIG. 1 for explaining a water level measurement process by the flow rate measuring apparatus using the ultrasonic sensor according to the present invention, and FIG. 2B is a graph showing a signal waveform according to the water level measurement result of FIG. 2A.

As shown in FIG. 2A, the 'transmission wave' emitted from the water level sensor 40 is reflected at the interface between the fluid 80 and the tube wall 11, and the reflected 'tube echo' is again reflected in the water level sensor 40. Will come back. Similarly, the 'transmission wave' emitted from the water level sensor 40 is reflected at the surface of the fluid 80 flowing through the pipe 10, and the reflected 'water echo' is returned to the water level sensor 40 again. .

As shown in FIG. 2B, when the emission time of the 'transmission wave' is referred to as 't ₀ ', the time at which the reception sensor 40 detects the 'tube echo' and the 'surface echo' is 't ₁ ', respectively. When it is referred to as' and 't ₂ ', a water level (WL) of the fluid 80 is derived based on this, and a calculation formula of this level is shown in the following equation (1).

Here, 'C' is the sound velocity of the fluid 80 previously known.

Figure 3a is a schematic cross-sectional view of Figure 1 for explaining the flow rate measurement process by the flow rate measurement apparatus using the ultrasonic sensor according to the present invention, Figure 3b is a graph showing a signal waveform according to the flow rate measurement result of FIG. .

As shown in FIG. 3A, the 'transmission wave' projected obliquely from the first flow rate sensor 50 into the fluid 80 is reflected at the interface of the fluid 80, and the reflected 'reflection wave' is the first flow rate sensor. And a second flow rate sensor 60 spaced apart from 50 by 'L'. After the above process, the ultrasonic wave is emitted from the second flow rate sensor 60 and the reflected wave is received from the first flow rate sensor 50.

As shown in FIG. 3B, when the firing time of the 'transmission wave' emitted by the first flow rate sensor 50 or the second flow rate sensor 60 is 't ₀ ', the first flow rate sensor 50 When the reception times of the received 'reverse reflection wave' and the 'reflection wave' received by the second flow rate sensor 60 are 't ₂₁ ' and 't ₁₂ ', respectively, the flow velocity of the fluid 80 is derived based on this. The calculation of this flow velocity is shown in the following equation.

Here, 'θ' represents the incident angle of the ultrasonic wave incident into the fluid 80, 'C' represents the sound velocity of the known fluid 80, 'A' represents a proportional constant, 'V' The flow velocity of the fluid 80 derived on the basis of FIG.

On the other hand, the sensor support (24, 94) is preferably a predetermined angle with the outer wall of the pipe 10, the surface engaging with each flow rate sensor 50, 60 so that 'Θ' can be acute angle.

4 is an electrical block diagram of a flow measurement apparatus using an ultrasonic sensor according to an embodiment of the present invention.

As shown in FIG. 4, the electrical configuration of the flow measuring apparatus 100 according to the present invention converts an electric signal received from the inside of the flow measuring apparatus 100 into a corresponding ultrasonic wave and outputs it to the outside, and inputs from the outside. Sensors 40, 50, and 60 for converting the received ultrasonic waves into corresponding electric signals and outputting the same to the flow rate measuring apparatus 100; A first preamplifier 171 for preamplifying an electric signal received from any one of the water level sensor 40 and the first flow rate sensor 50; A first pulse generator 161 for generating an electrical signal having a predetermined frequency, for example, 1 MHz; The signal received from the first pulse generator 161 is output to any one of the water level sensor 40 and the first flow rate sensor 50, and among the signals received from the water level sensor 40 and the first flow rate sensor 50. A sensor selector 151 outputting any one to the first preamplifier 171; A second preamplifier 173 for preamplifying the electric signal received from the second flow rate sensor 60; A second pulse generator 163 generating an electric signal having a predetermined frequency, for example, 1 MHz and outputting the electric signal to the second flow rate sensor 60; A trigger 180 for operating the first pulse generator 161 or the second pulse generator 163; A pulse selector 153 for outputting one of a signal received from the trigger 180, that is, a trigger signal and a reset signal, to any one of the first pulse generator 161 and the second pulse generator 163; A noise removing unit 191 for removing noise, ie, an electric signal other than a band generated by the pulse generators 161 and 163, from the electrical signals received from the first preamplifier 171 or the second preamplifier 173. ); An input selector 155 for outputting any one of signals received from the first preamplifier 171 and the second preamplifier 173 to the noise canceller 191; An amplifier 193 for amplifying the noise-free electric signal; An amplified electrical signal is an electrical signal in an analog form, the ADC 195 for converting it into a digital signal; A key input unit 130 for generating various key signals; Various data, for example, the display unit 120 for displaying the water level, the flow rate and the flow rate of the pipe 10; And a power supply unit 140 for supplying driving power to the components of the control unit 110 and the flow rate measuring apparatus 100.

In the above-described configuration, the power supply unit 140 may be formed of a primary or secondary battery and peripheral circuit elements thereof, or may be formed of a transformer, a converter, and peripheral circuit elements that step down AC voltage. Next, the key input unit 130 may include an alphanumeric key button, a function key button, and peripheral circuit elements thereof. Next, the display unit 120 is preferably implemented with a liquid crystal display (LCD) and peripheral circuit elements thereof. Next, each of the selectors 151, 153, and 155 is preferably implemented with a transistor for switching operation and a peripheral circuit element thereof. Next, the control unit 110 is preferably implemented with a microcomputer and the internal memory, the water level calculation and the flow rate calculation formula corresponding to the above-described equations (1) and (2) are stored in the internal memory, and the flow rate of the pipe 10 is measured. The control algorithms of the sensor selector 151, the pulse selector 153, the input selector 155, and the trigger 180 are stored in an internal memory.

Next, as described with reference to FIGS. 1 to 4, the process performed by the controller 100 to measure the flow rate of the pipe 10 will be described in detail.

First, a user manipulates a key button for measuring a flow rate of the pipe 10, and accordingly, the key input unit 130 outputs a corresponding key signal to the controller 110.

Next, the controller 100 controls the sensor selector 151 so that the water level sensor 40 is connected to the first preamplifier 171 and the first pulse generator 161, and the first pulse generator 161. Control the pulse selector 153 to be connected to the trigger 180 and control the input selector 155 to be connected to the first preamplifier 171 and the noise canceller 191; The trigger 180 is controlled to output the trigger signal to the first pulse generator 161. Accordingly, the water level sensor 40 emits an ultrasonic wave into the pipe 10 as shown in FIG. 2A, receives the 'tube echo' and 'surface echo', which are reflected waves of the ultrasonic wave, and corresponds to electricity. The signal is output to the first preamplifier 171. Next, the electrical signal amplified by the first preamplifier 171 is input to the controller 110 through the noise canceller 191, the amplifier 193, and the ADC 195, and accordingly, the controller 110. 2b obtains 't ₁ ' and 't ₂ ' as shown in FIG. 2B and calculates the water level WL based thereon.

Next, the controller 100 controls the sensor selector 151 so that the first flow rate sensor 50 is connected to the first preamplifier 171 and the first pulse generator 161, and generates the first pulse. After the pulse selector 153 is controlled to connect the unit 161 and the trigger 180, and the input selector 155 is controlled to connect the second preamplifier 173 and the noise canceller 191. ; The trigger 180 is controlled to output the trigger signal to the first pulse generator 161. Accordingly, the first flow rate sensor 50 emits an ultrasonic wave into the pipe 10 as shown in FIG. 3A, and the second flow rate sensor 60 receives the 'reflected wave' of the ultrasonic wave and corresponds to electricity. The signal is output to the second preamplifier 173. Next, the electrical signal amplified by the second preamplifier 173 is input to the controller 110 through the noise canceller 191, the amplifier 193, and the ADC 195, and accordingly, the controller 110. Obtains 't ₁₂ ' as shown in FIG. 3B.

Next, the controller 110 controls the sensor selector 151 such that the first flow rate sensor 50 is connected to the first preamplifier 171 and the first pulse generator 161, and generates a second pulse. After controlling the pulse selector 153 so that the unit 163 and the trigger 180 are connected, and controls the input selector 155 so that the first preamplifier 171 and the noise canceller 191 are connected. ; The trigger 180 is controlled to output a trigger signal to the second pulse generator 163. Accordingly, the second flow rate sensor 60 emits ultrasonic waves into the pipe 10, and the first flow rate sensor 50 receives the 'reverse reflected wave' of the ultrasonic waves and amplifies the corresponding electrical signal with the first preamplification. Output to the unit 171. Next, the electrical signal amplified by the first preamplifier 171 is input to the controller 110 through the noise canceller 191, the amplifier 193, and the ADC 195, and accordingly, the controller 110. Obtains 't ₂₁ ' as shown in FIG. 3B.

Next, the control unit 110 calculates the flow rate (V) based on the 't ₁₂ ' and 't ₂₁ ' obtained above.

Next, the controller 110 obtains the cross-sectional area of the fluid 80 based on the cross-sectional area of the pipe 10 previously input through the water level WL and the key input unit 130 previously obtained, and the cross-sectional area of the fluid 80 thus obtained. The flow rate of the fluid 80 flowing through the pipe 10 is calculated based on the flow rate V obtained above.

The apparatus for measuring the flow rate using the ultrasonic sensor of the present invention is not limited to the above-described embodiments, and may be variously modified and implemented within the range permitted by the technical idea of the present invention. For example, a pulse generator that performs the same function without having the first pulse generator 161 and the second pulse generator 163 may be disposed between the pulse selector 153 and the trigger 180. Alternatively, the first pulse generator 161 and the second pulse generator 163 are used for the flow rate measurement, each having a third pulse generator responsible for level measurement and pipe thickness measurement. You might choose.

According to the flow rate measuring apparatus using the ultrasonic sensor of the present invention as described above, by providing a water level sensor separately from the two flow rate sensors, it is possible to calculate the water level of the pipe and to accurately measure the flow rate based on these.

In addition, by providing a belt for fastening the clamp and an attachment hole whose portion is a magnet, the flow rate measuring device can be easily separated from the pipe, and the mounting can be easily performed. Furthermore, the distance between the two flow rate sensors, that is, 'L' shown in FIG. 3A, needs to be changed according to the cross-sectional area of the pipe, so that it is easy to do this through the guide rail.

Claims (8)

A level sensor for sensing a level of fluid flowing through a pipe; A first flow rate sensor and a second flow rate sensor for detecting a flow rate of the fluid flowing through the pipe; Signal output means for generating an electrical signal having a predetermined frequency; Selecting a signal that outputs the electrical signal to any one of the water level sensor, the first flow rate sensor and the second flow rate sensor, and receives a signal from any one of the water level sensor, the first flow rate sensor and the second flow rate sensor Means and Control a switching operation of the signal selection means, output a trigger signal for operating the signal output means to cause the water level sensor, the first flow rate sensor or the second flow rate sensor to emit ultrasonic waves, and input from the signal selection means And a control means for calculating a water level and a flow rate of the fluid flowing through the pipe based on the received signal, and calculating a flow rate based on the water level and the flow rate. The method of claim 1, An attachment hole attached to the lower position of the pipe while the water level sensor is mounted; A first clamp fixed to a lower position of the pipe with the first flow rate sensor mounted thereon; And a second clamp fixed to a lower portion of the pipe that is symmetrical to the first clamp while the second flow rate sensor is mounted. The method of claim 2, Includes a guide rail connecting the first clamp and the second clamp, One end of the guide rail is fixed to the first clamp, the flow rate measuring device using an ultrasonic sensor, characterized in that the guide hole through which the other end of the guide rail passes through the side of the second clamp. The method of claim 3, wherein The site of contact with the pipe outer wall of the attachment port is a flow rate measuring device using an ultrasonic sensor, characterized in that made of a magnet. The method of claim 4, wherein The flow rate measuring apparatus using the ultrasonic sensor, characterized in that the guide rail is engraved scale. The method according to any one of claims 1 to 5, The signal selection means Selecting a sensor for outputting an electric signal received from the signal output means to any one of the water level sensor and the first flow rate sensor, and outputs any one of the signal received from the water level sensor and the first flow rate sensor to the control means part; The signal output means is classified into a first pulse generator for generating an electrical signal having a predetermined frequency and outputting it to the second flow rate sensor and a second pulse generator for generating an electrical signal having a predetermined frequency and outputting the electrical signal to the sensor selection unit. A pulse selector configured to output a trigger signal received from the control means to any one of the first pulse generator and the second pulse generator; And an input selector configured to output one of the signal input from the sensor selector and the second flow rate sensor to the control means. The method of claim 6, The water level determined by the control means is

(Wherein, WL is the water level, C is the sound velocity of the fluid flowing through the pipe, t ₁ is the time when the water level sensor detected the ultrasonic waves reflected from the inner wall of the pipe to which the attachment is attached, t ₂ is And the ultrasonic wave reflected from the surface of the fluid is time detected by the water level sensor.). The method of claim 7, wherein The flow rate obtained by the control means is

,

And

(Where V is the flow rate, L is the distance between the first clamp and the second clamp, Θ is the ultrasonic wave incident of the first flow rate sensor and the second flow rate sensor incident on the fluid flowing through the pipe during the ultrasonic emission) Angle of incidence, C is the speed of sound of the fluid flowing through the pipe, A is a proportional constant, t ₁₂ is the time when the second flow sensor detects the ultrasonic waves reflected from the surface of the fluid, and t ₂₁ is the surface of the fluid Ultrasonic wave reflected from the time is detected by the first flow rate sensor.).

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