TW202202814A - Ultrasonic flow measurement device, controller therefor and ultrasonic flow measuring method - Google Patents

Abstract

An ultrasonic flow measurement device, a controller therefor, and an ultrasonic flow measuring method are disclosed. A controller for an ultrasonic flow measurement device in which a pair of ultrasonic sensors is disposed at least one side of a measuring tube through which fluid flows, includes a plurality of switches respectively connected to the pair of ultrasonic sensors to turn on or off a signal receiving path for transmitting a receiving signal; a noise canceling unit to cancel noise of the receiving signal transmitted to the signal receiving path; a time-to-digital converter to output a digital code corresponding to a time difference between a receiving time of the receiving signal from which the noise has been canceled and a transmitting time of a transmission signal; and a control unit to receive two digital codes output respectively during forward signal transmission and reverse signal transmission with respect to a moving direction of the fluid, and to calculate a flow velocity and a flow rate of the fluid using the received two digital codes.

Description

Ultrasonic flow measurement device, controller therefor, and ultrasonic flow measurement method

This embodiment relates to an ultrasonic flow measurement device suitable for small diameter pipes, a controller therefor, and an ultrasonic flow measurement method.

The time difference ultrasonic flowmeter is to place two piezoelectric ultrasonic sensors with a specific resonance frequency in the pipeline through which the fluid flows, and transmit and receive ultrasonic signals between the two piezoelectric ultrasonic sensors. A device for measuring the velocity and flow of fluids.

These conventional ultrasonic flow meters are used in various fields, such as various industrial sites.

However, in the case of small diameter or low flow pipes, the ultrasonic measurement method has the problem of no measurement or measurement error, because the distance between the ultrasonic sensors is very close, or the ultrasonic transit time difference is small due to the low flow rate .

Therefore, there is a need to develop a flow measurement device suitable for small diameter pipes.

This embodiment can provide an ultrasonic flow measurement device suitable for small diameter pipes, a controller therefor, and an ultrasonic flow measurement method.

According to one embodiment, the controller for an ultrasonic flow measurement device, wherein a pair of ultrasonic sensors is disposed on at least one side of a measuring tube through which the fluid flows, the controller may include: a plurality of switches, respectively connected to The pair of ultrasonic sensors is used to turn on or off the signal receiving path used for transmitting the receiving signal, so as to transmit the transmitting signal; the noise eliminating unit is used to eliminate the noise of the receiving signal transmitted to the signal receiving path; the time digital a converter, outputting a digital code, the digital code corresponding to the time difference between the reception time of the reception signal from which the noise is eliminated and the transmission time of the transmission signal; and a control unit, receiving in a positive direction relative to the moving direction of the fluid The two digital codes respectively output during the forward signal transmission and the reverse signal transmission are used to calculate the flow velocity and flow rate of the fluid.

The plurality of switches may include a first switch and a second switch, the first switch may be connected to a signal receiving path between any one of the pair of ultrasonic sensors and the time-to-digital converter, and is opposite to the time-to-digital converter The signal receiving path is closed during the transmission of the forward signal in the moving direction of the fluid, and the second switch can be connected to the signal receiving between the other one of the pair of ultrasonic sensors and the time-to-digital converter path, and closes the signal receiving path during the transmission of the reverse signal relative to the moving direction of the fluid.

The switch may comprise a T/R (transmit/receive) switch.

The control unit can be determined by not including the ratio of the transit distance of the area between the ultrasonic sensor and the measuring tube to the transit distance of the ultrasonic signal between the two ultrasonic sensors, to correct the transit time corresponding to the digital code, and use the corrected transit time to calculate the flow rate and the flow rate of the fluid.

、

獲得，在該反向訊號發射的期間的該通過時間可由方程式

、

獲得，c可為該流體的聲速，v可為該流體的平均速度，L可為該兩個超音波感測器之間的該超音波訊號的該通過距離，L'可為不包括該超音波感測器與該測量管之間的區域的該通過距離，而θ可為該超音波感測器的傾角。The transit time during the transmission of the forward signal can be obtained from the equation

,

Obtained, the transit time during the transmission of the reverse signal can be obtained from the equation

,

Obtain, c can be the sound velocity of the fluid, v can be the average velocity of the fluid, L can be the passing distance of the ultrasonic signal between the two ultrasonic sensors, and L' can be excluding the ultrasonic The passing distance of the area between the ultrasonic sensor and the measuring tube, and θ may be the inclination angle of the ultrasonic sensor.

得到，而在該反向訊號發射過程中，該第二通過時間由方程式

得到，c為該流體的聲速，v為該流體的平均速度，L為該兩個超音波感測器之間的該超音波訊號的該通過距離，而θ是該超音波感測器的傾角。The control unit can calculate the first transit time corresponding to the digital code and the second transit time calculated by the equation, and correct the first transit time by the calculated average value. During the forward signal transmission, the second transit time is given by the equation

obtained, and during the transmission of the reverse signal, the second transit time is given by the equation

Obtain, c is the sound velocity of the fluid, v is the average velocity of the fluid, L is the passing distance of the ultrasonic signal between the two ultrasonic sensors, and θ is the inclination of the ultrasonic sensor .

The noise cancellation unit may include a low noise amplifier (LNA).

According to one embodiment, an ultrasonic flow measurement device may include a measurement tube through which fluid flows; a pair of ultrasonic sensors disposed on at least one side of the measurement tube; and a control portion connected to the measurement tube, the control portion Comprising the controller according to any one of claims 1-3 and 5, and a housing accommodating the controller.

The ultrasonic flow measurement device may further include a connecting pipe, which connects the measuring pipe and the control part, and wherein a cable is arranged to electrically connect the pair of ultrasonic sensors and the controller.

According to one embodiment, the ultrasonic flow measurement method of the ultrasonic flow measurement device includes a time-to-digital converter to measure the transit time between a pair of ultrasonic sensors, the pair of ultrasonic sensors The measuring device is arranged on at least one side of the measuring tube through which the fluid flows, and may comprise the steps of: measuring the ultrasonic wave by the time-to-digital converter by emitting an ultrasonic signal in a forward direction relative to the moving direction of the fluid The forward transit time of the signal; by transmitting the ultrasonic signal in the reverse direction, the reverse transit time of the ultrasonic signal is measured by the time-to-digital converter; using the measured forward transit time and reverse The velocity and flow of the fluid are calculated over time.

、

來獲得，c可為該流體的聲速，v可為該流體的平均速度，L可為該兩個超音波感測器之間的該超音波訊號的該通過距離，L'可為不包括該超音波感測器與該測量管之間的區域的該通過距離，而θ可為該超音波感測器的傾角。In the step of measuring the forward transit time, the forward transit time measured by the time-to-digital converter can be corrected by the equation, and during the forward signal transmission, the forward transit time can be obtained by the equation

,

to obtain, c can be the sound velocity of the fluid, v can be the average velocity of the fluid, L can be the passing distance of the ultrasonic signal between the two ultrasonic sensors, and L' can be excluding the The passing distance of the area between the ultrasonic sensor and the measuring tube, and θ may be the inclination angle of the ultrasonic sensor.

、

來獲得，c可為該流體的聲速，v可為該流體的平均速度，L可為該兩個超音波感測器之間的該超音波訊號的該通過距離，L'可為不包括該超音波感測器與該測量管之間的區域的該通過距離，而θ可為該超音波感測器的傾角。In the step of measuring the reverse transit time, the reverse transit time measured by the time-to-digital converter can be corrected by the equation, and in the reverse signal transmission process, the reverse transit time can be obtained by the equation

,

to obtain, c can be the sound velocity of the fluid, v can be the average velocity of the fluid, L can be the passing distance of the ultrasonic signal between the two ultrasonic sensors, and L' can be excluding the The passing distance of the area between the ultrasonic sensor and the measuring tube, and θ may be the inclination angle of the ultrasonic sensor.

得到，c可為該流體的聲速，v可為該流體的平均速度，L為該兩個超音波感測器之間的該超音波訊號的該通過距離，而θ可為該超音波感測器的傾角。In the step of measuring the forward transit time, the average value of the forward transit time measured by the time-to-digital converter and the transit time calculated by the equation can be calculated, and the forward transit time can be calculated by During the forward signal transmission process, the transit time can be calculated by the equation

Obtain, c can be the sound velocity of the fluid, v can be the average velocity of the fluid, L can be the passing distance of the ultrasonic signal between the two ultrasonic sensors, and θ can be the ultrasonic sensor the inclination of the device.

得到，c可為該流體的聲速，v可為該流體的平均速度，L為該兩個超音波感測器之間的該超音波訊號的該通過距離，而θ可為該超音波感測器的傾角。In the step of measuring the reverse transit time, the average of the reverse transit time measured by the time-to-digital converter and the transit time calculated by the equation can be calculated, and the reverse transit time can be calculated by The average value is corrected. During the reverse signal transmission, the transit time can be calculated by the equation

Obtained, c can be the sound speed of the fluid, v can be the average velocity of the fluid, L is the passing distance of the ultrasonic signal between the two ultrasonic sensors, and θ can be the ultrasonic sensor tilt angle of the device.

According to one embodiment, a switch and an LNA are provided on the signal receiving path connected to the ultrasonic sensor, the switch is closed when transmitting a signal, and the switch is open when receiving a signal, so that when a weak signal is received, the overall sensitivity of the receiver can increase and noise can decrease.

According to an embodiment, it is possible to reduce the error rate of the measured values since the overall sensitivity of the receiver can be increased and the noise reduced.

According to an embodiment, when a high voltage noise generated by an external factor is received as a signal in the form of a shock wave, the switch is operated to protect the internal circuit and possibly stable measurement.

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

However, the technical idea of the present invention is not limited to some embodiments to be described, but can be implemented in various forms, and within the scope of the technical idea of the present invention, one or more elements may be selectively combined and replaced to used between examples.

Also, unless explicitly defined and described, terms (including technical and scientific terms) used in the embodiments of the present invention will be commonly understood by those of ordinary skill in the art to which the present invention belongs. Commonly used terms, such as terms defined in dictionaries, may be interpreted in consideration of contextual meanings in the relevant technical field.

In addition, the terms used in the embodiments of the present invention are used to describe the embodiments, and are not used to limit the present invention.

In this specification, the singular form may also include the plural form, unless the context specifically dictates otherwise, if it is described as "A and/and at least one (or more than one) of B and C", it may include one which may be combined with A One or more of all combinations of , B, and C.

Also, terms such as first, second, A, B, (a), and (b) may be used when describing constituent elements of the embodiments of the present invention.

These terms are only used to distinguish a constituent element from other constituent elements, and the terms are not used to limit the nature, order, or sequence of the constituent elements.

Also, if an element is described as being "connected," "coupled," or "contacting" another element, it is directly connected, coupled, or in contact with the other element. In addition, it may include that the component is "connected," "coupled," or "contacted" by another component between the component and another component.

Furthermore, when described as being formed or placed on the "top (top) or bottom (bottom)" of each component, the top (top) or bottom (bottom) includes not only the case where the two components are in direct contact, but also A situation where one or more other components are formed or disposed between two components. Further, when expressed as "top (top) or bottom (bottom)", not only the upward direction but also the downward direction based on one component may be included.

An embodiment proposes a new concept, wherein the signal transmission path and the signal reception path are respectively connected to the ultrasonic sensor, and the switch is arranged on the signal reception path, so that the switch is turned off when a signal is sent, and the switch is turned off when a signal is received. The switch is on.

1a to 1f are views showing an ultrasonic flow measurement device according to an embodiment of the present invention.

1a and 1b, an ultrasonic flow measurement device according to an embodiment of the present invention may include a measurement tube 100 through which fluid flows, an ultrasonic sensor 200, a control part 300, and a connection tube 400.

The measuring tube 100 is formed in a cylindrical shape so that the fluid can flow through an internal flow path. The measuring tube 100 is, for example, inserted and connected to the middle of water and sewage pipes and connected to pipes inside the water and sewage pipes, and the diameter of the pipes and the diameter of the flow path in the measuring pipe 100 may be the same.

The measuring tube 100 may include a main body part 110 , a fixing part 120 , a coupling part 130 and a cover 140 . The main body part 110 is formed in a cylindrical shape and has a flow path through which the fluid flows, and the fixing part 120 has a pair formed on one side or both sides of the main body part 110, and the pair of ultrasonic sensors 200 are provided on the fixing part On 110 , a pair of coupling parts 130 are formed at both ends of the body part 110 and connected to the pipe, and a cover 140 is coupled to the pair of fixing parts 120 to seal the interior of each fixing part 120 . In addition, the fixing part 120 may have a connecting hole 100a through which a cable for connecting the ultrasonic sensor 200 and the control part 300 is inserted on one side thereof.

In addition, the material of the measuring tube 100 may include synthetic resin and metal. At this time, the main body portion 110 , the fixing portion 120 , and the coupling portion 130 constituting the measuring tube 100 may be integrally formed.

The ultrasonic sensor 200 may be disposed obliquely and coupled to one or both sides of the measurement tube 100 , and includes a pair to transmit and receive ultrasonic signals to a fluid flowing in a flow path inside the measurement tube 100 . That is, the ultrasonic sensor 200 may include a first ultrasonic sensor 200a and a second ultrasonic sensor 200b. The first ultrasonic sensor 200a can transmit ultrasonic signals and the second ultrasonic sensor 200b can receive ultrasonic signals, or the second ultrasonic sensor 200b can transmit ultrasonic signals and the first ultrasonic sensor 200a can receive ultrasonic signals.

At this time, the ultrasonic sensor 200 may be arranged to be spaced apart from the flow path inside the measuring tube 100 by a predetermined distance. The transit distance of the ultrasonic signal can be increased by the separation distance.

The control part 300 may be connected to the pair of ultrasonic sensors 200 installed in the measuring tube 100, and by receiving ultrasonic signals from the pair of ultrasonic sensors 200 and utilizing the transit time difference of the transmitted ultrasonic signals, The flow velocity and flow rate of the fluid flowing through the flow path inside the measuring tube 100 are calculated.

The control part 300 may include a casing 310 and a controller 320 . The controller 320 may be disposed inside the housing 310, and the controller 320 may be connected to the ultrasonic sensor installed in the measuring tube 100 by a cable, and by using the space between the two ultrasonic sensors. Transmit and receive ultrasonic signals to measure fluid velocity and flow. In addition, a connection hole 300 a through which a cable for connecting the ultrasonic sensor 200 and the controller 300 is inserted may be formed on one side of the housing 310 .

The connecting pipe 400 may be provided between the measuring pipe 100 and the control part 300 by means of a plurality of fasteners 100b formed on one side of the measuring pipe 100 and a plurality of fasteners 300b formed on one side of the control part 300 Screwed and fixedly coupled.

The connecting tube 400 connects the connecting hole 100a formed on one side of the measuring tube 100 and the connecting hole 300a formed on one side of the casing 310 so that the cable connecting the ultrasonic sensor and the controller is located inside the casing And being prevented from being contacted from the outside, the connecting tube 400 is fixedly connected to the measuring tube 100 .

As shown in FIG. 1 c , instead of using the connecting tube 400 described in FIG. 1 b , it is also possible to directly connect the connecting hole 100 a of the measuring tube 100 and the connecting hole 300 a of the control unit 300 .

The ultrasonic flow measurement device according to the present embodiment may have some changes in configuration as required, as shown in FIGS. 1 d to 1 f .

2a and 2b are views for explaining the connection relationship between the ultrasonic sensor and the control section.

2a and 2b, according to an embodiment, a pair of ultrasonic sensors 200a and 200b disposed in the measuring tube 100 and the control part 300 may be connected by a cable 10 passing through the connecting tube 400. That is, the cable 10 may be disposed in and connected to the connection hole 100 a formed on one side of the measurement tube 100 , the connection pipe 400 , and the connection hole 300 a formed on one side of the housing 310 .

In addition, since the measurement tube 100 and the control unit 300 are connected by the connection tube 400 and are provided to be spaced apart by the length of the connection tube 400, thermal insulation and insulation are possible.

3 is a cross-sectional view showing the structure of an ultrasonic flow measurement device according to an embodiment of the present invention.

3 , the ultrasonic flow measurement device according to the embodiment is a reflection type, and includes a pair of ultrasonic sensors 200 a and 200 b respectively provided at a pair of fixing parts 120 a formed on one side of the main body part 110 and 120b, and the pair of ultrasonic sensors 200a and 200b are spaced apart from the flow path through which the fluid flows by a predetermined distance L11 and L21. Here, the diameter of the ultrasonic sensor and the diameter of the fixing portion may be designed to be the same as each other.

In this case, the ultrasonic sensors 200a and 200b can be divided into a first part that generates one end of the actual ultrasonic signal and a second part that supports the first part. The diameter of the ultrasonic sensor may represent the diameter of the first portion, and the diameter of the first portion may be equal to or smaller than the diameter of the second portion.

At this time, the fixing portions 120a and 120b are formed by inclining a predetermined angle θ with respect to the central axis of the main body portion, and the predetermined angle may be formed in a range of 30 degrees to 60 degrees, preferably, 45 degrees.

The ultrasonic signal generated from the first ultrasonic sensor 200a can be reflected once on the inner surface of the flow path and transmitted to the second ultrasonic sensor 200b, or the ultrasonic signal generated from the second ultrasonic sensor 200b The signal can be reflected once on the inner surface of the flow path and transmitted to the first ultrasonic sensor 200a.

According to this embodiment, since the pair of ultrasonic sensors are arranged to be spaced apart from the flow path by a predetermined distance, the passing path of the ultrasonic signal can be increased by L11+L21.

4 is a view showing a detailed configuration of the controller shown in FIG. 2a, and FIGS. 5a and 5b are views for explaining a signal transmission path and a signal reception path.

4 , the controller 320 according to an embodiment may include a control unit 321 and a time-to-digital converter (TDC) 322 , a first noise cancellation unit 323 , a second noise cancellation unit 324 , a first switch 325 , and a second switch 326 , interface 327 , display unit 328 and output unit 329 .

The control unit 321 can generate a transmission signal having a number of pulses, which is transmitted by the ultrasonic sensors 200a and 200b in the forward or reverse direction with respect to the fluid flow.

The control unit 321 may be provided with a digital code generated from the time-to-digital converter 322, which corresponds to the time difference between the transmitted signal and the received signal, and is measured using this time difference (ie, transit time) corresponding to the received digital code Fluid velocity and flow.

The control unit 321 may measure the transit time of the forward flow or reverse flow of the fluid, respectively. In the general method of measuring the flow velocity using the ultrasonic transit time difference, the reliability increases when the transit time difference in the forward and reverse directions increases. Therefore, in this embodiment, the ultrasonic sensor is arranged to be spaced apart from the flow path in the measuring tube by a predetermined distance to increase the passing time difference, thereby extending the passing path.

The time-to-digital converter 322 is a device that converts time information into a digital code, which can generate a digital code corresponding to the time difference (ie, transit time) between two input signals (ie, the transmit signal and the receive signal). Here, the input signal can be in the form of pulses or simple rising signals from different signal sources.

Such time-to-digital converters are used, for example, in analog-to-digital converters (ADCs), phase locked loops (PLLs), delay locked loops (DLLs), image sensors, shape scanning devices, distance measuring devices, and the like.

The time-to-digital converter 322 is usually directly connected for impedance matching with the ultrasonic sensor. However, when the final signal is received, since the high frequency signal has a relatively low signal level and is very sensitive to interference, a low noise amplifier is used to improve the overall sensitivity of the receiver and reduce noise.

The first noise canceling unit 323 is connected to the signal receiving path P12 between the time-to-digital converter 322 and the first ultrasonic sensor, and can cancel the noise of the signal received by the first ultrasonic sensor 200a. That is, the first noise canceling unit 323 can cancel out-of-band signals received by the first ultrasonic sensor 200a.

The second noise canceling unit 324 is connected to the signal receiving path P22 between the time-to-digital converter 322 and the second ultrasonic sensor, and can cancel the noise of the signal received by the second ultrasonic sensor 200b. That is, the second noise canceling unit 324 can cancel out-of-band signals received by the second ultrasonic sensor 200b.

Here, the case where the first noise cancellation unit 323 and the second noise cancellation unit 324 are implemented as a low noise amplifier (LNA) is taken as an example for description, but the present invention is not limited thereto, and various components are applicable.

The first switch 325 can be connected to the signal receiving path P12 between the first noise canceling unit 323 and the first ultrasonic sensor 200a to be turned on or off. When the signal is transmitted through the first ultrasonic sensor 200a, the first switch 324 can be closed, thereby preventing the signal transmitted by the signal transmission path P11 from entering the signal reception path P12.

The second switch 326 can be connected to the signal receiving path P22 between the second noise canceling unit 324 and the second ultrasonic sensor 200b to be turned on or off. When the signal is transmitted through the second ultrasonic sensor 200b, the second switch 326 can be closed, thereby preventing the signal transmitted by the signal transmission path P21 from entering the second signal reception path P22.

In this case, the first switch 325 and the second switch 326 may be, for example, T/R (transmit/receive) switches.

When a high-voltage noise in the form of a shock wave that may be generated by an external factor is received together with the signal in the process of transmitting or receiving a signal, the first switch 325 and the second switch 326 operate so that the internal circuit can be protected and stable Measurement.

The interface 327 can transmit or receive data by interacting with external terminals. Here, the interface 327 may be, for example, a universal asynchronous receiver-transmitter (UART) that converts parallel data into serial data and transmits, but is not limited thereto, and various methods may be applied.

The display unit 328 can display the calculated flow rate, instantaneous flow rate and integrated flow rate on the screen.

The output unit 329 can output the calculated flow, the instantaneous flow and the integral flow in an analogous manner. For example, the output unit 329 may convert the calculated flow into the magnitude of current or voltage to output the converted flow.

The output unit 329 may include a digital-to-analog converter (DAC) 329a and an analog output unit 329b. The digital-to-analog converter 329a can convert the digital signal into an analog signal and output it to the analog output unit 329b.

5a, the signal transmission path P11 according to the embodiment may include a control unit 321, a time-to-digital converter 322, and a first ultrasonic sensor 200a. The transmitted signal with pulses to be transmitted generated by the control unit 321 can be provided to the first ultrasonic sensor 200a through the time-to-digital converter 322 .

The signal receiving path P22 according to the embodiment may include the second ultrasonic sensor 200 b , the second switch 326 , the second noise removing unit 324 , the time-to-digital converter 322 and the control unit 321 . The signal received by the second ultrasonic sensor 200b can be provided to the control unit 321 through the second switch 326, the second noise removing unit 324 and the time-to-digital converter 322 in sequence.

5b, the signal transmission path P21 according to the embodiment may include a control unit 321, a time-to-digital converter 322, and a second ultrasonic sensor 200b. The transmitted signal with pulses to be transmitted generated by the control unit 321 can be provided to the second ultrasonic sensor 200b through the time-to-digital converter 322 .

The signal receiving path P12 according to the embodiment may include the first ultrasonic sensor 200 a , the first switch 325 , the first noise removing unit 323 , the time-to-digital converter 322 and the control unit 321 . The signal received by the first ultrasonic sensor 200a can be provided to the control unit 321 through the first switch 325, the first noise removing unit 323 and the time-to-digital converter 322 in sequence.

FIG. 6 is a view showing an ultrasonic flow measurement method according to a first embodiment of the present invention.

6 , the ultrasonic flow measurement device (hereinafter referred to as the measurement device) according to the embodiment emits an ultrasonic signal in a forward direction with respect to the flow of the fluid (S610), and can measure the ultrasonic signal emitted in the forward direction. Forward transit time (t _downstream ) of the sonic signal. The forward transit time may be obtained from a time-to-digital converter (S620).

其中c為該流體的聲速，v為該流體流動的平均速度，L為該兩個超音波感測器之間的該超音波訊號的該通過距離，而θ是該超音波感測器的傾角。這裡，參考圖3，L是L11、L12、L21及L22的總和。The forward transit time can be defined in Equation 1 below. [Equation 1]

where c is the sound speed of the fluid, v is the average velocity of the fluid flow, L is the passing distance of the ultrasonic signal between the two ultrasonic sensors, and θ is the inclination of the ultrasonic sensor . Here, referring to FIG. 3, L is the sum of L11, L12, L21, and L22.

Next, the measuring device transmits the ultrasonic signal in the reverse direction with respect to the fluid flow (S630), and may measure the reverse transit time (t _upstream ) of the ultrasonic signal transmitted in the reverse direction. The reverse transit time may be obtained from the time-to-digital converter (S640).

The reverse transit time can be defined in [Equation 2] below. [Equation 2]

、

The above [Equation 1] and [Equation 2] are summarized as the following [Equation 3]. [Equation 3]

,

[方程式5]

Next, the measuring device may calculate the flow rate using the transit times (t _upstream and t _downstream ) (S650). The flow velocity v and the sound velocity c are obtained from the two equations of [Equation 3], respectively, and are defined in the following [Equation 4] and [Equation 5]. [Equation 4]

[Equation 5]

Next, the measuring device may calculate the volume flow using the calculated flow rate (v) (S660).

、

At this time, since the area affected by the flow in the measuring tube is within the range of the ultrasonic signal passing distance, L'=L12+L21, so the forward passing time and the reverse passing time can be calculated as the passing distance L' and the passing distance L , and is defined in Equation 6 below. [Equation 6]

,

、

If the above [Equation 6] is defined as the transit time, it can be expressed as the following [Equation 7]. [Equation 7]

,

If [Equation 7] is applied to [Equation 4], the element in [Equation 4] (t _upstream - t _downstream ) (that is, the difference Δt between the two transit times) is calculated using the area through which the fluid does not flow, L11 and L21 to calculate. However, when the reverse time is subtracted from the forward time of the total passing distance L (=L11+L12+L21+L22), the same value as the calculation result of the time difference of only (L12+L22) is obtained by compensation. Therefore, if applied without multiplying by the ratio of the passing distance shown in [Equation 7], it is defined as [Equation 8] below. [Equation 8]

If [Equation 8] is used, the volumetric flow rate (ie, flow rate q _v ) is defined as follows [Equation 9] [Equation 9]

Here, A represents the area of the cross section of the flow path through which the fluid flows in the measuring tube.

FIG. 7 is a view showing an ultrasonic flow measurement method according to a second embodiment of the present invention.

7 , the ultrasonic flow measurement device (hereinafter referred to as the measurement device) according to the embodiment emits an ultrasonic signal in a forward direction with respect to the flow of the fluid (S710), and can measure the ultrasonic signal emitted in the forward direction. Forward transit time (t _downstream ) of the sonic signal. The forward transit time (t _downstream ) may be obtained from the time-to-digital converter (S720).

At this time, the measuring device may calculate an average value of the obtained forward passing time t _downstream and the forward passing time calculated by Equation 1, and correct the calculated average value by the forward passing time t _downstream (S721).

Next, the measuring device transmits the ultrasonic signal in the reverse direction with respect to the fluid flow (S730), and the reverse transit time (t _upstream ) of the ultrasonic signal transmitted in the reverse direction may be measured. The reverse transit time may be obtained from the time-to-digital converter (S740).

At this time, the measuring device may calculate an average value of the acquired reverse transit time t _upstream and the reverse transit time calculated by Equation 2, and correct the calculated average value by the reverse transit time t _upstream ( S741 ).

Next, the measuring device may calculate the flow rate using the transit times (t _upstream and t _downstream ) (S750).

Next, the measuring device may calculate the volume flow using the calculated flow rate (S760).

The term "unit" as used in this embodiment refers to a software or hardware component such as a Field Programmable Logic Gate Array (FPGA) or ASIC, and a "unit" performs some of these roles. However, "unit" is not limited to software or hardware. A "unit" may be configured to be stored in an addressable storage medium or may be structured to execute one or more processors. Thus, a "unit" includes, by way of example, software components, object-oriented software components, class and task components, programs, functions, properties and procedures, subroutines, program code segments, drivers, firmware, microcode, Circuits, data, databases, data structures, tables, arrays and variables. The functionality provided by components and "units" may be combined with a smaller number of components and "units" or further separated into additional components and "units". Furthermore, components and "units" may be implemented to execute one or more CPUs in a device or secure multimedia card.

The above has been described with reference to the preferred embodiments of the present invention, but it should be understood that those skilled in the art can make various modifications and changes to the present invention without departing from the spirit and scope of the present invention, as set forth in the following claims .

10: Cable 100: Measuring tube 100a: connection hole 100b: Fasteners 110: Main body 120: Fixed part 120a: Fixed part 120b: Fixed part 130: Coupling part 140: Cover 200: Ultrasonic sensor 200a: Ultrasonic sensor 200b: Ultrasonic sensor 300: Control Department 300a: connection hole 300b: Fasteners 310: Shell 320: Controller 321: Control Unit 322: Time to Digitizer 323: The first noise elimination unit 324: Second noise removal unit 325: First switch 326: Second switch 327: Interface 328: Display unit 329: output unit 329a: Digital-to-Analog Converters 329b: Analog output unit 400: connecting pipe L11: Predetermined distance L12: Distance L21: Predetermined distance L22: Distance P11: Signal transmission path P12: Signal receiving path P21: Signal transmission path P22: Signal receiving path θ: inclination angle

[Figs. 1a to 1f] are views showing an ultrasonic flow measurement device according to an embodiment of the present invention.

[ FIGS. 2 a and 2 b ] are views for explaining the connection relationship between the ultrasonic sensor and the control section.

[ Fig. 3 ] is a cross-sectional view showing the structure of an ultrasonic flow measurement device according to an embodiment of the present invention.

[Fig. 4] is a view showing a detailed configuration of the controller shown in Fig. 2a.

5a and 5b are views for explaining a signal transmission path and a signal reception path.

[ Fig. 6 ] is a view showing an ultrasonic flow measurement method according to a first embodiment of the present invention.

[ Fig. 7 ] is a view showing an ultrasonic flow measurement method according to a second embodiment of the present invention.

200a: Ultrasonic sensor

200b: Ultrasonic sensor

320: Controller

321: Control Unit

322: Time to Digitizer

323: The first noise elimination unit

324: Second noise removal unit

325: First switch

326: Second switch

327: Interface

328: Display unit

329: output unit

329a: Digital-to-Analog Converters

329b: Analog output unit

P11: Signal transmission path

P12: Signal receiving path

P21: Signal transmission path

P22: Signal receiving path

Claims (12)

A controller for an ultrasonic flow measurement device, wherein a pair of ultrasonic sensors are arranged on at least one side of a measuring tube through which fluid flows, the controller comprising: A plurality of switches are respectively connected to the pair of ultrasonic sensors to open or close the signal receiving path for transmitting and receiving signals; a plurality of noise canceling units to cancel the noise of the received signal transmitted to the signal receiving path; a time-to-digital converter that outputs a digital code corresponding to the time difference between the time of reception of the received signal from which the noise is removed and the time of transmission of the transmitted signal; and The control unit receives plural digital codes respectively output during the period of forward signal transmission and reverse signal transmission relative to the moving direction of the fluid, and uses the received plural digital codes to calculate the flow rate and flow of the fluid , Wherein, the control unit corrects the correspondence by the ratio of the passing distance of the area excluding the ultrasonic sensor and the measuring tube to the passing distance of the ultrasonic signal between the two ultrasonic sensors Based on the transit time of the digital code, and using the corrected transit time, the flow velocity and the flow rate of the fluid are calculated. The controller of claim 1, wherein the plurality of switches include a first switch and a second switch, The first switch is connected to the signal receiving path between any one of the pair of ultrasonic sensors and the time-to-digital converter, and closes the forward signal transmission relative to the moving direction of the fluid during the transmission of the forward signal signal receiving path, The second switch is connected to the signal receiving path between the other of the pair of ultrasonic sensors and the time-to-digital converter, and is closed during the transmission of the reverse signal relative to the moving direction of the fluid The signal receiving path. The controller of claim 2, wherein the switch comprises a T/R (transmit/receive) switch. The controller of claim 1, wherein the transit time during the transmission of the forward signal is given by the equation

,

Obtained, the transit time during the transmission of the reverse signal is given by the equation

,

Obtain, c is the sound velocity of the fluid, v is the average velocity of the fluid, L is the passing distance of the ultrasonic signal between the two ultrasonic sensors, and L' is not including the ultrasonic sensor The passing distance to the area between the measuring tube, θ is the inclination of the ultrasonic sensor. A controller for an ultrasonic flow measurement device, wherein a pair of ultrasonic sensors are arranged on at least one side of a measuring tube through which fluid flows, the controller comprises: a plurality of switches, respectively connected to the pair of ultrasonic sensors a device to turn on or off a signal receiving path for transmitting and receiving signals; a plurality of noise elimination units to eliminate the noise of the received signal transmitted to the signal receiving path; a time-to-digital converter to output a digital code, the digital code corresponding to the time difference between the reception time of the reception signal from which the noise is eliminated and the transmission time of the transmission signal; and a control unit to receive the period of forward signal transmission and reverse signal transmission with respect to the moving direction of the fluid The plurality of digital codes output respectively, and the received plurality of digital codes are used to calculate the flow velocity and flow rate of the fluid, wherein the control unit is based on the passage time corresponding to the digital code and the passage time calculated by the equation. The average value is used to correct the transit time corresponding to the digital code. During the forward signal transmission process, the transit time calculated by the equation is calculated by the equation

is obtained, and during the transmission of the reverse signal, the transit time calculated by the equation is given by the equation

Obtain, c is the sound velocity of the fluid, v is the average velocity of the fluid, L is the passing distance of the ultrasonic signal between the two ultrasonic sensors, and θ is the inclination of the ultrasonic sensor . The controller of claim 1, wherein the noise cancellation unit includes a low noise amplifier (LNA). An ultrasonic flow measurement device, comprising: The measuring tube through which the fluid flows; a pair of ultrasonic sensors disposed on at least one side of the measuring tube; and A control part, connected to the measuring tube, the control part comprising the controller according to any one of Claims 1-3 and 5 and a housing for accommodating the controller. The ultrasonic flow measurement device according to claim 7, further comprising a connecting pipe connecting the measuring pipe and the control part, wherein a cable for electrically connecting the pair of ultrasonic sensors and the controller is provided. An ultrasonic flow measurement method of an ultrasonic flow measurement device, the ultrasonic flow measurement device includes a time-to-digital converter to measure the transit time between a pair of ultrasonic sensors, the pair of ultrasonic sensors being arranged in a fluid flowing through at least one side of the measuring tube, the method comprising the steps of: measuring the forward transit time of the ultrasonic signal by the time-to-digital converter by emitting the ultrasonic signal in a forward direction relative to the direction of movement of the fluid; measuring the reverse transit time of the ultrasonic signal by the time-to-digital converter by transmitting the ultrasonic signal in the reverse direction; and Calculate the flow rate and flow of the fluid using the measured forward and reverse transit times, Wherein, in the calculation step, the ratio of the passing distance of the region excluding the ultrasonic sensor and the measuring tube to the passing distance of the ultrasonic signal between the two ultrasonic sensors , to correct the transit time corresponding to the digit, The flow rate and the flow rate of the fluid are calculated using the corrected transit time. The ultrasonic flow measurement method according to claim 9, wherein, in the step of measuring the forward transit time, the forward transit time measured by the time-to-digital converter is corrected by an equation, and during the forward signal transmission process , the forward transit time is given by the equation

,

to obtain, c is the sound speed of the fluid, v is the average speed of the fluid, L is the passing distance of the ultrasonic signal between the two ultrasonic sensors, and L' is the ultrasonic sensor that does not include the is the passing distance of the area between the detector and the measuring tube, and θ is the inclination of the ultrasonic sensor. The ultrasonic flow measurement method according to claim 9, wherein, in the step of measuring the reverse transit time, the reverse transit time measured by the time-to-digital converter is corrected by an equation, during the reverse signal transmission process , the reverse transit time is given by the equation

,

to obtain, c is the sound velocity of the fluid, v is the average velocity of the fluid, L is the passing distance of the ultrasonic signal between the two ultrasonic sensors, and L' is not including the ultrasonic sensing is the passing distance of the area between the sensor and the measuring tube, and θ is the inclination of the ultrasonic sensor. An ultrasonic flow measurement method of an ultrasonic flow measurement device, the ultrasonic flow measurement device includes a time-to-digital converter to measure the transit time between a pair of ultrasonic sensors, the pair of ultrasonic sensors being arranged in a fluid at least one side of a measuring tube flowing through, the method comprising the steps of: measuring the forward direction of the ultrasonic signal by the time-to-digital converter by emitting the ultrasonic signal in a forward direction relative to the direction of movement of the fluid transit time; measuring the reverse transit time of the ultrasonic signal by the time-to-digital converter by transmitting the ultrasonic signal in the reverse direction; and using the measured forward transit time and reverse transit time to Calculate the flow rate and flow of the fluid, wherein, in the step of measuring the forward transit time, the forward transit time measured by the time-to-digital converter is the positive transit time measured by the time-to-digital converter. Corrected to the average of the transit time and the transit time calculated by Equation 1, which is calculated by Equation 1 during forward signal transmission

It is obtained that, in the step of measuring the reverse transit time, the reverse transit time measured by the time-to-digital converter is calculated by the reverse transit time measured by the time-to-digital converter and by Equation 2 The transit time calculated by Eq. 2 is corrected by the average value of the transit time calculated by Eq.

Obtain, c is the sound velocity of the fluid, v is the average velocity of the fluid, L is the passing distance of the ultrasonic signal between the two ultrasonic sensors, and θ is the inclination of the ultrasonic sensor .

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