JP6187343B2 - Ultrasonic measuring instrument - Google Patents

Description

  The present invention relates to an ultrasonic measuring instrument that measures the flow velocity, flow rate, interface level, and the like of a fluid using ultrasonic waves.

  As one of measuring instruments that measure the flow velocity, flow rate, interface level, and the like of a fluid flowing in a pipe, an ultrasonic measuring instrument using ultrasonic waves is known. This ultrasonic measuring instrument has advantages such as a simple structure, no mechanical moving parts, a wide rangeability (measuring range in which accuracy can be guaranteed), and compatibility with large-diameter pipes. As a representative example of this ultrasonic measuring instrument, there are one using a transmission method (propagation time difference method), and one using a pulse Doppler method and a reflection method.

  The ultrasonic measuring instrument using the transmission method transmits and receives ultrasonic signals in an oblique direction with respect to the fluid flowing in the pipe, and the propagation time when the ultrasonic signals are transmitted and received in the direction along the fluid flow, and the fluid flow The flow velocity of the fluid flowing in the pipe is measured by obtaining the difference from the propagation time when the ultrasonic signal is transmitted and received in the direction opposite to the above. On the other hand, an ultrasonic measuring device using the pulse Doppler method or the reflection method transmits an ultrasonic signal in an oblique direction to the fluid flowing in the pipe, and reflects it from bubbles or fine particles (particles) contained in the fluid. It receives a signal and measures the flow velocity of the fluid flowing in the pipe.

  Patent Document 1 below discloses an ultrasonic flowmeter that can measure the flow velocity, flow rate, and the like of a fluid flowing in a pipe in a non-full state with higher accuracy than before. Specifically, in the ultrasonic flowmeter disclosed in Patent Document 1 below, fluid flows through a pair of ultrasonic transmitters and receivers that are set so that directional axes intersect each other at a liquid surface having a predetermined depth. Installed in the pipe (bottom of pipe) and receives ultrasonic signals reflected by the liquid level (interface) of the fluid that flows in the pipe in a non-full state, so that the flow velocity, flow rate, and liquid level (interface level) Is measuring.

Japanese Patent No. 4325922

  By the way, the ultrasonic flowmeter disclosed in Patent Document 1 described above transmits an ultrasonic signal obliquely upward from one ultrasonic transmitter / receiver of a pair of ultrasonic transmitters / receivers installed in a pipe, The ultrasonic wave signal reflected from the liquid surface and incident from obliquely above is received by the other ultrasonic transmitter / receiver to measure the interface level of the fluid flowing in the non-full state. For this reason, measurement cannot be performed unless the ultrasonic transmitter / receiver installed in the pipe is filled with fluid (the interface level of the fluid is located above the ultrasonic transmitter / receiver), There is a problem that the measurable range such as the interface level is limited.

  Moreover, since the ultrasonic flowmeter disclosed in Patent Document 1 described above needs to install an ultrasonic transmitter / receiver in a pipe, it is complicated to install the ultrasonic transmitter / receiver by drilling the pipe or the like. There is a problem that work is required and installation requires man-hours and costs. For example, in order to install an ultrasonic transmitter / receiver in a pipe while a plant or the like is in operation, stop the fluid flowing through the pipe where the ultrasonic transmitter / receiver is to be installed, empty the pipe, and then perform the installation work. Therefore, it is considered that installation is often difficult, and there is a possibility of opportunity loss.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an ultrasonic measuring instrument that can measure an interface level in a wider range than before and can be easily installed. And

In order to solve the above-mentioned problem, the ultrasonic measuring instrument of the present invention transmits an ultrasonic signal (U1, U2) to a fluid (X) flowing through a pipe (TB) and also transmits the ultrasonic signal via the fluid. In the ultrasonic measuring device (1, 2) that receives an acoustic wave signal and measures at least one of the flow velocity and flow rate of the fluid, the ultrasonic signal (U1) is oblique to the fluid flow direction (D). And transmitting / receiving element (11) attached to the outer surface of the pipe so as to receive a reflected signal of the ultrasonic signal obtained from the fluid, and of the reflected signal received by the transmitting / receiving element, A first calculation unit (24a) for obtaining an interface level of the fluid based on a change in intensity of a reflected signal of the ultrasonic signal (U2) directed in a direction perpendicular to a fluid flow direction. .
According to the present invention, among the reflected signals received by the transmitting / receiving element attached to the outer surface of the pipe so as to transmit the ultrasonic signal in an oblique direction with respect to the fluid flow direction, the reflected signal is perpendicular to the fluid flow direction. The interface level of the fluid is obtained based on the intensity change of the reflected signal of the ultrasonic signal directed in the direction.
Further, in the ultrasonic measuring instrument according to the present invention, the intensity of the reflected signal of the ultrasonic signal in which the first calculation unit is directed in a direction perpendicular to the fluid flow direction is a predetermined threshold (TH). It is characterized in that the position that exceeds the maximum value is determined as the interface of the fluid.
Further, the ultrasonic measuring instrument according to the present invention uses the reflected signal of the ultrasonic signal transmitted in an oblique direction with respect to the fluid flow direction among the reflected signals received by the transmitting / receiving element. A second calculation unit (24b) for obtaining a flow velocity distribution of the fluid in the radial direction of the fluid, wherein the first calculation unit reflects the ultrasonic signal in a direction perpendicular to the fluid flow direction. When the intensity of the fluid does not exceed the threshold value, the fluid interface is determined based on the fluid flow velocity distribution obtained by the second computing unit.
In the ultrasonic measuring instrument according to the present invention, the first calculation unit may include a region (R1) in which the flow velocity distribution of the fluid is obtained by the second calculation unit and a region in which the flow velocity distribution of the fluid is not obtained ( The position of the boundary with R2) is determined as the interface of the fluid.
In addition, the ultrasonic measuring instrument of the present invention includes a third calculation unit (24c) that obtains at least one of a flow velocity and a flow rate of the fluid based on the ultrasonic signal that has passed through the fluid, and the first calculation The unit calculates the interface level of the fluid when the third calculation unit cannot measure the flow velocity and flow rate of the fluid.
In the ultrasonic measuring instrument according to the present invention, the transmission / reception element has a first surface (P1) that is in contact with an outer surface of the pipe, and an angle formed with respect to the first surface is an acute angle. It is attached to the outer surface of the said piping via the attachment member (12) which has a 2nd surface (P2) in which an element is mounted.
The ultrasonic measuring instrument of the present invention is characterized in that the state of the interface of the fluid is determined from the temporal change of the interface level obtained by the first calculation unit.

  According to the present invention, among reflected signals received by a transmitting / receiving element attached to the outer surface of a pipe so as to transmit an ultrasonic signal in an oblique direction with respect to the fluid flow direction, the reflected signal is perpendicular to the fluid flow direction. Since the interface level of the fluid is obtained based on the intensity change of the reflected signal of the ultrasonic signal directed in any direction, it is possible to measure the interface level in a wider range than before and perform installation easily There is an effect that can be.

It is a figure which shows schematic structure of the ultrasonic measuring device by 1st Embodiment of this invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. It is a figure which shows the structure of the transmission / reception part with which the ultrasonic measuring device by 1st Embodiment of this invention is provided. It is a block diagram which shows the principal part structure of the measurement part with which the ultrasonic measuring device by 1st Embodiment of this invention is provided. It is a figure which shows an example of the received signal obtained with the ultrasonic measuring device by 1st Embodiment of this invention. It is a figure for demonstrating the determination method of the interface level in the ultrasonic measuring device by 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the ultrasonic measuring device by 1st Embodiment of this invention. It is a figure which shows schematic structure of the ultrasonic measuring device by 2nd Embodiment of this invention. It is a block diagram which shows the principal part structure of the measurement part with which the ultrasonic measuring device by 2nd Embodiment of this invention is provided. It is a flowchart which shows operation | movement of the ultrasonic measuring device by 2nd Embodiment of this invention. It is a figure for demonstrating the modification of this invention.

  Hereinafter, an ultrasonic measuring device according to an embodiment of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a diagram showing a schematic configuration of an ultrasonic measuring instrument according to the first embodiment of the present invention. 2 is a cross-sectional view taken along line AA in FIG. As shown in FIG. 1, the ultrasonic measuring instrument 1 of the present embodiment includes a transmitting / receiving unit 10 and a measuring unit 20 connected by a cable C, and the fluid X flowing in the pipe TB using an ultrasonic signal. The flow velocity, flow rate, and interface level (the liquid level position of fluid X) are measured. As shown in FIGS. 1 and 2, the pipe TB through which the fluid X flows is assumed to have an annular shape in cross section, and the flow direction of the fluid X is a direction indicated by a symbol D in the drawings.

  Here, it is assumed that the ultrasonic measuring instrument 1 of the present embodiment measures the flow velocity and flow rate of the fluid X using the reflection correlation method. In other words, an ultrasonic signal is transmitted a plurality of times in an oblique direction with respect to the fluid X flowing in the pipe TB, and bubbles and fine particles (particles) included in the fluid X (hereinafter, these are collectively referred to as “bubble B”). ) Is received over a plurality of times, and correlation processing is performed on the received signal to measure the flow velocity and flow rate of the fluid X flowing in the pipe TB.

  The transmission / reception unit 10 is attached to the outer surface of the pipe TB through which the fluid X flows, and transmits an ultrasonic signal in an oblique direction to the fluid X flowing through the pipe TB based on the drive signal from the measurement unit 20. A reflected signal of the ultrasonic signal obtained from the fluid X is received. As shown in FIGS. 1 and 2, the transmission / reception unit 10 is capable of measuring the flow velocity, flow rate, and interface level of the fluid X even when the fluid X flows in the pipe TB in a non-full state. It is attached to the outer surface at the bottom of the pipe TB. In addition, the transmission / reception part 10 can be attached, without processing, such as drilling with respect to piping TB.

  FIG. 3 is a diagram illustrating a configuration of a transmission / reception unit included in the ultrasonic measurement device according to the first embodiment of the present invention. As shown in FIG. 3, the transmission / reception unit 10 includes a transducer 11 (transmission / reception element) and a wedge member 12 (attachment member). The transducer 11 and the wedge member 12 are covered by a case, but the case is not shown in FIG. The transducer 11 includes a piezoelectric element such as a piezo element, is driven by a drive signal output from the measurement unit 20, transmits an ultrasonic signal for the fluid X flowing in the pipe TB, and is obtained from the fluid X. A reflected signal of the ultrasonic signal is received and a received signal is output.

  The wedge member 12 is a member (jig) used for attaching the transducer 11 to the pipe TB. The wedge member 12 is formed of a resin or metal, for example, and is a substantially cubic or substantially rectangular parallelepiped member having an inclined surface. Specifically, the wedge member 12 has the mounting surface P1 (first surface) in contact with the outer surface at the bottom of the pipe TB, and the angle formed with respect to the mounting surface P1 is an acute angle, and the transducer 11 is mounted. The mounting surface P2 (inclined surface: second surface) is attached to the pipe TB so that the inclination direction of the mounting surface P2 is along the flow direction D of the fluid X. The ultrasonic signal output from the transducer 11 is transmitted to the fluid X flowing in the pipe TB through the inside of the wedge member 12.

  Here, the transducer 11 is mounted on a mounting surface P2 formed at an acute angle with respect to the mounting surface P1, and the ultrasonic signal from the transducer 11 is strongly output in the normal direction of the mounting surface P2. Therefore, the ultrasonic signal from the transducer 11 is strongly transmitted as an ultrasonic signal U1 that is incident on the fluid X flowing in the pipe TB in an oblique direction, as shown in FIG. However, since the ultrasonic signal output from one point of the transducer 11 propagates as a spherical wave as shown by a broken line in FIG. 3, the ultrasonic signal U2 directed in a direction perpendicular to the fluid X flowing in the pipe TB is also included. Exists. In the present embodiment, the interface level of the fluid X is obtained based on the intensity change of the reflected signal of the ultrasonic signal U2.

  The measurement unit 20 outputs a drive signal to the cable C to transmit an ultrasonic signal (ultrasonic signals U1, U2) from the transmission / reception unit 10 (transducer 11), and transmits / receives the transmission / reception unit 10 transmitted via the cable C. The received signal from is processed to measure the flow rate, flow rate, and interface level of fluid X. Specifically, correlation processing is performed on the received signal obtained by receiving the reflected signal of the ultrasonic signal U1 shown in FIG. 3 to obtain the flow velocity (flow velocity distribution) and flow rate of the fluid X flowing in the pipe TB. Further, the interface level of the fluid X is obtained based on the intensity change of the reflected signal of the ultrasonic signal U2 shown in FIG.

  FIG. 4 is a block diagram showing the main configuration of the measurement unit provided in the ultrasonic measuring instrument according to the first embodiment of the present invention. As shown in FIG. 4, the measurement unit 20 includes a switching unit 21, a transmission circuit unit 22, a reception circuit unit 23, a control processing unit 24, and an operation display unit 25. 4 includes a connector CN to which a cable C having two core wires can be connected, and connection wires L1 and L2 connected to the two core wires of the cable C connected to the connector CN. The two transducers can be connected via the cable C.

  The switching unit 21 switches a transducer to be connected to the transmission circuit unit 22 and the reception circuit unit 23 under the control of the control processing unit 24. Specifically, the switching unit 21 is connected to the terminal T10 connected to the transmission circuit unit 22, the terminal T11 connected to the connection line L1, the terminal T12 connected to the connection line L2, and the reception circuit unit 23. A terminal T20, a terminal T21 connected to the connection line L1, and a terminal T22 connected to the connection line L2. Then, under the control of the control processing unit 24, the switching unit 21 switches whether the terminal T10 is connected to the terminals T11, T12 and switches whether the terminal T20 is connected to the terminals T21, T22.

  In the present embodiment, it is assumed that one transducer 11 shown in FIG. 3 is connected to the connection line L1 via the cable C. Therefore, it is assumed that the switching unit 21 is connected to the terminal T11 and the terminal T20 is connected to the terminal T21 as shown in FIG. 4 under the control of the control processing unit 24. In this embodiment, since there is only one transducer 11, the terminals T12 and T22 and the connection line L2 are not used.

  The transmission circuit unit 22 outputs a drive signal for generating ultrasonic signals U1 and U2 to be transmitted to the fluid X to the switching unit 21 under the control of the control processing unit 24. Here, the drive signal is a pulse-like (burst-like) signal having a predetermined time interval (for example, about several hundred μsec). The reception circuit unit 23 includes, for example, an amplifier and an A / D converter (both not shown), and receives a reception signal output from the transmission / reception unit 10 (transducer 11) under the control of the control processing unit 24. And is converted into a digital signal and output to the control processing unit 24.

  The control processing unit 24 controls the transmission circuit unit 22 to perform transmission control of the ultrasonic signals U1 and U2 with respect to the fluid X, and controls the reception circuit unit 23 to perform sampling control of the reception signal obtained from the transmission / reception unit 10. Do. The control processing unit 24 also performs switching control of the switching unit 21 as necessary. In addition, the control processing unit 24 performs signal processing on the reception signal (digital signal) output from the reception circuit unit 23 to measure the flow velocity (flow velocity distribution), the flow rate, and the interface level of the fluid X.

  The control processing unit 24 includes an interface level calculation unit 24a (first calculation unit) and a flow velocity distribution calculation unit 24b (second calculation unit). The interface level calculation unit 24a obtains the interface level of the fluid X based on the intensity change of the reflected signal of the ultrasonic signal U2 directed in the direction perpendicular to the flow direction D of the fluid X. FIG. 5 is a diagram illustrating an example of a received signal obtained by the ultrasonic measuring device according to the first embodiment of the present invention. The reception signals S1 and S2 shown in FIG. 5 are obtained by transmitting and receiving the reflected signals of the ultrasonic signals U1 and U2 continuously transmitted from the transmission / reception unit 10 at the predetermined time interval (for example, about several hundred μsec). It is a received signal obtained by sequentially receiving.

  As shown in FIG. 5, the received signals S1 and S2 include portions including waveforms W11 to W13, W15, W21 to W23, and W25 having small amplitudes and waveforms W14 and W24 having large amplitudes. Waveforms W11 to W13, W15, W21 to W23, and W25 having small amplitudes are waveforms obtained by receiving a reflected signal that is generated when the ultrasonic signal U1 is reflected by the bubble B included in the fluid X. Here, the bubble B contained in the fluid X moves in the flow direction D by a distance corresponding to the flow velocity of the fluid X between the transmission of the ultrasonic signal U1 and the transmission of the next ultrasonic signal U1. To do. Therefore, there is a time lag between the waveforms W11 to W13 and W15 included in the received signal S1 and the waveforms W21 to W23 and W25 included in the received signal S2 by the distance traveled by the bubble B as shown in FIG. Has occurred.

  On the other hand, the waveforms W14 and W24 having a large amplitude are waveforms obtained by receiving a reflected signal generated by the ultrasonic signal U2 being reflected by the interface of the fluid X. Since the waveforms W14 and W24 are obtained by receiving the reflected signal of the ultrasonic signal U2 that is perpendicularly incident (or substantially perpendicularly incident) on the interface of the fluid X, the waveforms W11 to W13, W15, and W21 are obtained. Amplitude is larger than -W23 and W25. In addition, since the waveforms W14 and W24 are due to the reflected signal of the ultrasonic signal U2 directed in the direction perpendicular to the flow direction D of the fluid X, if there is no fluctuation of the interface of the fluid X, it is included in the received signal S1. There is no time lag between the waveform W14 generated and the waveform W24 included in the received signal S2. The waveforms W14 and W24 are superimposed with the same waveforms as the waveforms W11 to W13, W15, W21 to W23, and W25 having small amplitudes described above.

  As described above, the waveforms W14 and W24 obtained by receiving the reflection signal generated by the reflection of the ultrasonic signal U2 by the interface of the fluid X receive the reflection signal generated by the reflection of the ultrasonic signal U1 by the bubble B. Compared to the obtained waveforms W11 to W13, W15, W21 to W23, and W25, the amplitude (intensity) is extremely large. For this reason, the interface level calculation unit 24a obtains amplitude changes (intensity changes) of the received signals S1 and S2 in which the intensity change of the reflected signal of the ultrasonic signal U2 directed in the vertical direction is reflected, and based on this intensity change. Thus, the interface level of the fluid X is obtained.

  FIG. 6 is a diagram for explaining a method for determining the interface level in the ultrasonic measuring instrument according to the first embodiment of the present invention, wherein (a) shows the intensity of the reflected signal of the ultrasonic signal U2 in the radial direction of the pipe. (B) is a figure which shows the flow velocity distribution of the fluid X in the radial direction of piping. The origin position “0” shown in FIG. 6 indicates the center position of the pipe TB, and the positions “−r” and “r” indicate the positions of both ends of the pipe TB in the traveling direction of the ultrasonic signal U2. Yes.

  As shown in FIG. 6A, the interface level calculation unit 24a has a position where the intensity exceeds the threshold value TH when there is a portion where the intensity of the reflected signal of the ultrasonic signal U2 exceeds a predetermined threshold value TH. Is determined as the interface of fluid X. In the example shown in FIG. 6A, the interface level calculation unit 24a determines that the position Q1 is the interface of the fluid X. That is, among the reflected signals of the ultrasonic signal U2, the reflected signal whose intensity does not exceed the threshold value TH is considered to have been obtained by being weakly reflected by the bubble B, while the reflected signal whose intensity exceeds the threshold value TH is It is considered that the light was strongly reflected at the interface of the fluid X. For this reason, the interface level calculation part 24a determines the position where the intensity | strength of the reflected signal of the ultrasonic signal U2 becomes the maximum exceeding the threshold value TH as the interface of the fluid X.

  In contrast, when there is no portion where the intensity of the reflected signal of the ultrasonic signal U2 exceeds the threshold value TH, the interface level calculation unit 24a is based on the flow velocity distribution of the fluid X obtained by the flow velocity distribution calculation unit 24b. Determine the X interface. Specifically, as shown in FIG. 6B, the interface level calculation unit 24a has a region R1 in which the flow velocity distribution of the fluid X has been obtained by the flow velocity distribution calculation unit 24b and a region R2 in which the flow velocity distribution of the fluid X has not been obtained. Is determined as the interface of the fluid X. Although the ultrasonic signals U1 and U2 can propagate inside the fluid X, they cannot propagate in the atmosphere. For this reason, it is considered that the fluid X exists in the region R1 in which the flow velocity distribution of the fluid X is obtained, and the fluid X does not exist in the region R2 in which the fluid velocity distribution of the fluid X is not obtained. For this reason, the interface level calculation unit 24a determines the boundary position Q2 between the region R1 in which the flow velocity distribution of the fluid X is obtained by the flow velocity distribution calculation unit 24b and the region R2 in which the flow velocity distribution of the fluid X is not obtained. Judged as an interface.

  The flow velocity distribution calculation unit 24b obtains the flow velocity distribution of the fluid X in the radial direction of the pipe TB using the reflected signal of the ultrasonic signal U1 transmitted in an oblique direction with respect to the flow direction D of the fluid X. Specifically, the flow velocity distribution calculation unit 24b divides a reception signal (for example, reception signals S1 and S2 shown in FIG. 5) sequentially obtained from the transmission / reception unit 10 into a plurality of divisions according to time positions, and correlates each division. Process. Then, the flow velocity distribution calculation unit 24b obtains the time interval at which the correlation is maximized for each of the above sections, and obtains the flow velocity of the fluid X for each section from each time interval, thereby obtaining the flow velocity of the fluid X in the radial direction of the pipe TB. Measure the distribution.

  The operation display unit 25 includes an operation device such as an operation button and a display device such as a liquid crystal display device. The operation display unit 25 configured as described above outputs an instruction input by the operator operating the operating device to the control processing unit 24 and also measures the fluid X obtained by the control processing unit 24 (flow velocity, flow rate, interface). Level). The operation display unit 25 can display various information other than the measurement result of the fluid X (for example, information indicating the internal state and measurement conditions of the ultrasonic measuring instrument 1).

  Next, the operation of the ultrasonic measuring instrument 1 having the above configuration will be described. FIG. 7 is a flowchart showing the operation of the ultrasonic measuring apparatus according to the first embodiment of the present invention. When the measurement is started, first, ultrasonic signals U1 and U2 are sequentially transmitted from the transducer 11 provided in the transmission / reception unit 10 to the fluid X flowing in the pipe TB, and the reflected signals of these ultrasonic signals U1 and U2 are transmitted. A receiving process is performed (step S11).

  Specifically, the transmission circuit unit 22 is controlled by the control processing unit 24 of the measurement unit 20, and a pulse-shaped (burst-shaped) drive signal having a predetermined time interval (for example, about several hundred μsec) is supplied to the transducer 11. The process to send to is performed. The drive signal from the transmission circuit unit 22 is input to the transmission / reception unit 10 via the switching unit 21 and the cable C in this order, whereby the ultrasonic signals U1 and U2 shown in FIG. Sequentially transmitted toward fluid X.

  The ultrasonic signal U1 incident on the fluid X propagates along a path PT1 (path oblique to the flow direction D of the fluid X) shown in FIG. Here, when the bubble B exists on the path PT1, a part of the ultrasonic signal U1 is reflected by the bubble B to generate a reflected signal. The reflected signal traces the path PT1 in the reverse direction and is received by the transducer 11. As a result, the reception signal output from the transceiver 10 (transducer 11) includes waveforms (W11 to W13, W15, W21 to W23, and W25 in FIG. 5) obtained by receiving the reflection signal caused by the bubble B. A similar waveform) is included.

  On the other hand, the ultrasonic signal U2 incident on the fluid X propagates along the path PT2 (path in the direction perpendicular to the flow direction D of the fluid X) shown in FIG. Here, when the ultrasonic signal U2 reaches the interface of the fluid X, most of the ultrasonic signal U2 is reflected to generate a reflected signal. The reflected signal traces the path PT2 in the reverse direction and is received by the transducer 11. Thereby, the reception signal output from the transmission / reception unit 10 (transducer 11) includes a waveform (a waveform similar to W14 and W24 in FIG. 5) obtained by receiving the reflection signal at the interface of the fluid X. It will be. Even when the bubble B exists on the path PT2, a part of the ultrasonic signal U2 is reflected to generate a reflected signal. This reflected signal is used for measuring the flow velocity, flow rate, and interface level of the fluid X. The description is omitted because it is not used.

  Next, a process of calculating the flow velocity distribution of the fluid X in the radial direction of the pipe TB is performed using reception signals sequentially output from the transmission / reception unit 10 (transducer 11) (step S12). Specifically, in the flow velocity distribution calculation unit 24b, the reception signal (digital signal) sequentially output from the reception circuit unit 23 is divided into a plurality of divisions according to time positions, and correlation processing is performed for each division. The maximum time interval is obtained for each of the above sections, and the process for obtaining the flow velocity of the fluid X for each section is performed from each time interval. By performing such processing, the flow velocity distribution of the fluid X in the radial direction of the pipe TB is obtained.

  Subsequently, processing for obtaining a change in the intensity of the reflected signal in the radial direction of the pipe TB is performed from the reception signals sequentially output from the transmission / reception unit 10 (transducer 11) (step S13). Specifically, in the interface level calculation unit 24a, the reception signal (for example, the reception signal S1 shown in FIG. 5) output from the reception circuit unit 23 is divided into a plurality of sections according to the time position, and the maximum for each section. Processing for obtaining the amplitude (maximum intensity) is performed. By performing such processing, processing for obtaining a change in the intensity of the reflected signal in the radial direction of the pipe TB is performed.

  Next, the interface level calculation unit 24a determines whether or not the interface (liquid level of the fluid X) can be determined from the intensity change of the reflected signal in the radial direction of the pipe TB calculated in step S13 (step S13). S14). Specifically, as shown in FIG. 6 (a), there is a position (position Q1 in FIG. 6 (a)) at which the intensity of the reflected signal of the ultrasonic signal U2 exceeds a predetermined threshold value TH. It is determined whether or not to do so. When it is determined from the change in the intensity of the reflected signal that the interface can be determined (when the determination result in step S14 is “YES”), the interface level measurement result (position Q1 in FIG. 6A) is displayed as an operation. It is displayed on the part 25 (step S15).

  On the other hand, when it is determined from the intensity change of the reflected signal that the interface cannot be determined (when the determination result in step S14 is “NO”), the fluid in the radial direction of the pipe TB calculated in step S12. From the flow velocity distribution of X, the interface level calculation unit 24a determines whether the interface can be determined (step S16). When it is determined from the flow velocity distribution of the fluid X that the interface can be determined (when the determination result in step S16 is “YES”), the interface level measurement result (position Q2 in FIG. 6B) is displayed as an operation. It is displayed on the part 25 (step S15). On the other hand, when it is determined from the flow velocity distribution of the fluid X that the interface cannot be determined (when the determination result of step S16 is “NO”), the inside of the pipe TB is empty (the fluid X is not flowing). A message to that effect is displayed on the operation display unit 25 (step S17).

  As described above, in this embodiment, the transducer 11 is attached to the outer surface of the pipe TB so as to transmit the ultrasonic signal U1 in an oblique direction with respect to the flow direction D of the fluid X flowing through the pipe TB. Among the reflected signals, the interface level of the fluid X is obtained based on the intensity change of the reflected signal of the ultrasonic signal U2 directed in the direction perpendicular to the flow direction D of the fluid X. For this reason, it is possible to measure the interface level of the fluid X in a wider range than before. Moreover, since the transducer 11 is attached to the outer surface of the pipe TB, it can be easily installed.

[Second Embodiment]
FIG. 8 is a diagram showing a schematic configuration of an ultrasonic measuring instrument according to the second embodiment of the present invention. In FIG. 8, the same components as those shown in FIG. 1 are denoted by the same reference numerals. As shown in FIG. 8, the ultrasonic measuring instrument 2 of the present embodiment includes two transmitting / receiving units 10a and 10b and a measuring unit 30 connected by a cable C. The ultrasonic measuring device 2 of the first embodiment shown in FIG. Similar to the sonic measuring instrument 1, the flow velocity, flow rate, and interface level of the fluid X flowing in the pipe TB are measured using an ultrasonic signal. However, the ultrasonic measuring device 2 of the present embodiment is capable of performing measurement using the transmission method in addition to the measurement using the reflection method (reflection correlation method) performed by the ultrasonic measurement device 1 of the first embodiment. Is possible.

  That is, the ultrasonic measuring device 2 of the present embodiment transmits and receives an ultrasonic signal in an oblique direction with respect to the fluid X flowing in the pipe TB, and propagates when the ultrasonic signal is transmitted and received in a direction along the flow of the fluid X. By obtaining the difference between the time and the propagation time when the ultrasonic signal is transmitted and received in the direction opposite to the flow of the fluid X, the flow velocity of the fluid X flowing in the pipe TB can be measured. In order to enable measurement using this transmission method, the ultrasonic measurement device 2 of this embodiment includes two transmission / reception units 10a and 10b.

  The transmission / reception units 10a and 10b have the same configuration as the transmission / reception unit 10 shown in FIG. 1, and are attached to the outer surface of the pipe TB through which the fluid X flows. Specifically, the transmission / reception unit 10a is attached to the outer surface at the bottom of the pipe TB, similarly to the transmission / reception unit 10 shown in FIG. 1, and is inclined toward the transmission / reception unit 10b based on the drive signal from the measurement unit 30. An ultrasonic signal is transmitted in the direction, and a reflected signal of the ultrasonic signal obtained from the fluid X or an ultrasonic signal transmitted from the transmission / reception unit 10b and transmitted through the fluid X is received. The transmission / reception unit 10b is upstream of the transmission / reception unit 10a and is attached to the outer surface in the upper part of the pipe TB, and ultrasonic waves are obliquely directed toward the transmission / reception unit 10a based on the drive signal from the measurement unit 30. A signal is transmitted, and an ultrasonic signal transmitted from the transmission / reception unit 10a and transmitted through the fluid X is received. In addition, these transmission / reception parts 10a and 10b can also be attached without processing such as drilling the pipe TB.

  FIG. 9 is a block diagram showing a main configuration of a measurement unit included in the ultrasonic measurement device according to the second embodiment of the present invention. In FIG. 9, the same components as those shown in FIG. 4 are denoted by the same reference numerals. As shown in FIG. 9, the measurement unit 30 has a configuration in which a flow rate / flow rate calculation unit 24c (third calculation unit) is added to the control processing unit 24 of the measurement unit 20 shown in FIG. Here, in this embodiment, the transducer (not shown) provided in the transmission / reception unit 10a is connected to the connection line L1 via the cable C, and the transducer (not shown) provided in the transmission / reception unit 10b is connected to the cable C. Is connected to the connection line L2.

  The flow velocity flow rate calculation unit 24c performs signal processing on the reception signal (digital signal) output from the reception circuit unit 23, and calculates the flow velocity and flow rate of the fluid X by the permeation method. Specifically, the flow rate / flow rate calculation unit 24c is configured such that the switching unit 21 receives the reception signal obtained when the transmission / reception unit 10a is connected to the reception circuit unit 23, and the switching unit 21 connects the transmission / reception unit 10b to the reception circuit unit 23. Signal processing is performed on the received signal obtained in this case, and the flow velocity and flow rate of the fluid X are calculated.

  That is, the flow rate flow rate calculation unit 24c transmits the ultrasonic signal transmitted from the transmission / reception unit 10b and transmitted through the fluid X, and the propagation time when the transmission / reception unit 10a receives the ultrasonic signal, and transmitted from the transmission / reception unit 10a and transmitted through the fluid X A difference from the propagation time when the ultrasonic signal is received by the transmission / reception unit 10b is obtained. Then, the flow rate of the fluid X is measured based on this difference, and the flow rate is measured from the product of the measured flow rate of the fluid X and the cross-sectional area inside the pipe TB.

  Next, the operation of the ultrasonic measuring instrument 2 having the above configuration will be described. FIG. 10 is a flowchart showing the operation of the ultrasonic measuring instrument according to the second embodiment of the present invention. When the measurement is started, first, an initial setting necessary for measuring the fluid X by the transmission method is performed (step S21). Specifically, the inner diameter of the pipe TB through which the fluid X flows, the mounting angles of the transmission / reception units 10a and 10b, the density and viscosity of the fluid X, the speed of sound, and the like are set in the measurement unit 30.

  When the above initial setting is completed, the control processing unit 24 of the measurement unit 30 determines whether or not to use the transmission method (step S22). Specifically, the control processing unit 24 determines whether or not an instruction for measuring the fluid X using the transmission method is input from the operation display unit 25. When it is determined not to use the transmission method (when the determination result of step S22 is “NO”), measurement by the reflection method is performed (step S23). That is, the same operation as that described with reference to FIG. 7 is performed.

  On the other hand, when it is determined that the transmission method is used (when the determination result of step S22 is “YES”), measurement by the transmission method is started (step S24). When measurement by the transmission method is started, first, the switching unit 21 is controlled by the control processing unit 24, the transmission / reception unit 10b is connected to the transmission circuit unit 22, and the transmission / reception unit 10a is connected to the reception circuit unit 23. It is said. Then, an ultrasonic signal is transmitted from the transducer (not shown) provided in the transmission / reception unit 10b to the fluid X flowing in the pipe TB, and the ultrasonic signal transmitted through the fluid X is transmitted (not shown) provided in the transmission / reception unit 10a. Processing (forward reception processing) received by the transducer is performed.

  Subsequently, the control processing unit 24 controls the switching unit 21 so that the transmission / reception unit 10 a is connected to the transmission circuit unit 22 and the transmission / reception unit 10 b is connected to the reception circuit unit 23. Then, an ultrasonic signal is transmitted from the transducer (not shown) provided in the transmission / reception unit 10a to the fluid X flowing in the pipe TB, and the ultrasonic signal transmitted through the fluid X is transmitted (not shown) provided in the transmission / reception unit 10b. Processing (reverse reception processing) received by the transducer is performed.

  Next, the control processing unit 24 determines whether or not an ultrasonic signal (transmission signal) that has passed through the fluid X has been received by the above-described forward reception process and reverse reception process (step S25). When it is determined that a transmission signal has not been received (when the determination result of step S25 is “NO”), measurement by the reflection method is performed (step S23). That is, the same operation as that described with reference to FIG. 7 is performed.

  Here, in this embodiment, as shown in FIG. 8, the transmission / reception units 10a and 10b are respectively attached to the outer surface at the bottom of the pipe TB and the outer surface at the top of the pipe TB. Then, when the fluid X flows in the pipe TB in a non-full state, the upper part in the pipe TB becomes a gas layer, so that the transmission signal is obtained in both the forward reception process and the reverse reception process described above. Is not received, and the flow rate and flow rate of the fluid X cannot be measured by the transmission method. For this reason, when the transmission signal is not received, measurement by the reflection method is performed to measure the flow velocity (flow velocity distribution), the flow rate, and the interface level of the fluid X.

  On the other hand, when it is determined that a permeation signal has been received (when the determination result in step S25 is “YES”), processing for calculating the flow velocity and flow rate of the fluid X by the permeation method is performed. That is, the flow rate flow rate calculation unit 24c performs the process of measuring the flow velocity and flow rate of the fluid X using the reception signal obtained by the forward direction reception processing and the reception signal obtained by the reverse direction reception processing. Specifically, there is a process for obtaining a difference between a propagation time when an ultrasonic signal is transmitted / received in a direction along the flow of the fluid X and a propagation time when an ultrasonic signal is transmitted / received in a direction against the flow of the fluid X. The flow rate of the fluid X is measured based on this difference, and the flow rate is measured from the product of the measured flow rate of the fluid X and the cross-sectional area of the pipe TB. When the above processing is completed, the measured flow velocity and flow rate of the fluid X are displayed on the operation display unit 25 (step S26).

  As described above, in this embodiment, when the permeation method is not used, the interface level of the fluid X is obtained by performing the same processing as in the first embodiment. For this reason, also in this embodiment, it is possible to measure the interface level of the fluid X in a wider range than before. Also in the present embodiment, the transmission / reception units 10a and 10b including the transducer (not shown) can be easily installed because they are attached to the outer surface of the pipe TB.

  Further, in the present embodiment, when the transmission method cannot be received when the transmission method is used, the same processing as that in the first embodiment is performed to determine the interface level of the fluid X and the like. ing. For this reason, when measurement by the transmission method becomes impossible, it can be easily and immediately determined whether the cause is due to the fluid X being in a non-full state or another cause. Can be confirmed.

  The ultrasonic measuring instrument according to the embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and can be freely changed within the scope of the present invention. For example, each of the ultrasonic measuring instruments 1 and 2 in the first and second embodiments described above calculates the interface level of the fluid X flowing in the pipe TB (the liquid level position of the fluid X at a certain time). The interface state of the fluid X (the degree of shaking of the interface) may be obtained (determined) from the time change of the interface level of the fluid X (for example, the time change of about 30 seconds).

  FIG. 11 is a diagram for explaining a modification of the present invention. In FIG. 11, as in FIG. 6, the center position of the pipe TB is set to the origin position “0”, and both end positions of the pipe TB in the traveling direction of the ultrasonic signal U <b> 2 (see FIG. 3) are set to the positions “−r”. ”And“ r ”. In a state where the interface of the fluid X is stable (when no wave-like shaking is generated), the ultrasonic signal U2 is incident perpendicularly to the interface of the fluid X (or almost perpendicular) as shown in FIG. Therefore, the intensity of the reflected signal is high, and the position where the reflected signal is obtained is almost constant. For this reason, the reflected signal of the ultrasonic signal U2 obtained in such a state has a high intensity and a small half-value width as indicated by a curve denoted by reference numeral R11 in the figure.

  On the other hand, when the interface of the fluid X is unstable (when a wave-like vibration is generated), the interface of the fluid X is undulated, and the ultrasonic signal U2 is applied to the interface of the fluid X. On the other hand, since the incident light is often oblique, the intensity of the reflected signal is lowered, and the position where the reflected signal is obtained also changes greatly. For this reason, the reflected signal of the ultrasonic signal U2 obtained in such a state has a low intensity and a large half-value width as indicated by a curve denoted by reference numeral R12 in the figure.

  For this reason, a threshold value (intensity threshold value) for the intensity of the received signal obtained by receiving the reflected signal of the ultrasonic signal U2 and a threshold value for the half value width (half value width threshold value) are set, and the intensity of the received signal exceeds the intensity threshold value. The interface state of the fluid X may be determined by comprehensively considering whether or not the half width of the received signal exceeds the half width threshold. For example, when the intensity of the received signal exceeds the intensity threshold and the half width of the received signal does not exceed the half width threshold, it is determined that the interface of the fluid X is in a stable state, and the intensity of the received signal Is not exceeding the intensity threshold and the half width of the received signal exceeds the half width threshold, it is determined that the interface of the fluid X is in an unstable state.

  In the ultrasonic measuring instrument 2 of the second embodiment described above, as shown in FIG. 8, the transceiver 10a is attached to the outer surface at the bottom of the pipe TB, and the transceiver 10b is attached to the outer surface at the top of the pipe TB. It was what has been. However, as long as the transmission / reception parts 10a and 10b can be measured by the transmission method, both may be attached to the outer surface of the bottom part of the pipe TB.

  In the above-described embodiment, the example in which the position where the intensity of the reflected signal of the ultrasonic signal U2 exceeds the predetermined threshold TH and is the maximum is described as the interface of the fluid X. Various methods other than the method using the threshold value TH can be used. For example, a method can be used in which a differential process is performed on the reflected signal of the ultrasonic signal U2 to determine a position where the inclination is 0 as an interface. When such a method is used, if there are a plurality of positions where the inclination is zero, the position where the intensity of the reflected signal of the ultrasonic signal U2 at these positions is maximized may be determined as the interface.

DESCRIPTION OF SYMBOLS 1, 2 Ultrasonic measuring device 11 Transmission / reception element 12 Wedge member 24a Interface level calculation part 24b Flow velocity distribution calculation part 24c Flow velocity flow rate calculation part D Flow direction P1 Mounting surface P2 Mounting surface R1, R2 area TB piping TH threshold value U1, U2 Ultrasonic wave Signal X Fluid

Claims (7)

In an ultrasonic measuring device that transmits an ultrasonic signal to a fluid flowing through a pipe, receives the ultrasonic signal via the fluid, and measures at least one of a flow velocity and a flow rate of the fluid,
A transmitting / receiving element attached to an outer surface of the pipe so as to transmit the ultrasonic signal in an oblique direction with respect to a flow direction of the fluid and receive a reflected signal of the ultrasonic signal obtained from the fluid;
A first calculation unit that obtains an interface level of the fluid based on a change in intensity of the reflected signal of the ultrasonic signal that is directed in a direction perpendicular to the flow direction of the fluid among the reflected signals received by the transmitting / receiving element. An ultrasonic measuring instrument comprising: and.   The first calculation unit determines that a position at which the intensity of the reflected signal of the ultrasonic signal in a direction perpendicular to the fluid flow direction exceeds a predetermined threshold value is the interface of the fluid. The ultrasonic measuring instrument according to claim 1, wherein: The flow velocity distribution of the fluid in the radial direction of the pipe is obtained using the reflected signal of the ultrasonic signal transmitted in an oblique direction with respect to the flow direction of the fluid among the reflected signals received by the transmitting / receiving element. A second computing unit,
When the intensity of the reflected signal of the ultrasonic signal directed in a direction perpendicular to the fluid flow direction does not exceed the threshold, the first calculation unit determines the fluid obtained by the second calculation unit. The ultrasonic measuring device according to claim 2, wherein an interface of the fluid is determined based on a flow velocity distribution.   The first computing unit determines a boundary position between a region where the fluid flow velocity distribution is obtained by the second computing unit and a region where the fluid flow velocity distribution is not obtained as the fluid interface. The ultrasonic measuring instrument according to claim 3. A third computing unit that obtains at least one of a flow velocity and a flow rate of the fluid based on the ultrasonic signal transmitted through the fluid;
The said 1st calculating part calculates | requires the interface level of the said fluid when the said 3rd calculating part cannot measure the flow velocity and flow volume of the said fluid. The ultrasonic measuring device according to claim 1.   The transmission / reception element includes an attachment member having a first surface that is in contact with an outer surface of the pipe, and a second surface on which the transmission / reception element is mounted with an acute angle formed with respect to the first surface. The ultrasonic measuring instrument according to any one of claims 1 to 5, wherein the ultrasonic measuring instrument is attached to an outer surface of the pipe via a pipe.   The ultrasonic measuring device according to any one of claims 1 to 6, wherein a state of an interface of the fluid is determined from a time change of an interface level obtained by the first calculation unit.

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