JP2010190775A - Ultrasonic flow rate measurement method and flow rate measurement apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic flow rate measurement method and flow rate measurement apparatus, capable of measuring a flow rate of the whole large-scale water passage with simple equipment. <P>SOLUTION: When the water passage is divided into a central part 120, a periphery 130 from the central part 120 to a wall surface or a bottom, and an external edge 140 next to the wall surface or the bottom, the flow velocity distribution of the periphery 130 of the water passage is measured by ultrasonic wave. The flow velocity distribution of the central part 120 of the water passage is interpolated with the measured flow velocity distribution to determine the flow rate of the whole water passage. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ultrasonic flow rate measuring method and a flow rate measuring apparatus for measuring a flow velocity distribution of a water channel with ultrasonic waves and measuring a flow rate of the entire water channel.

  In hydroelectric power generation, the generator output varies depending on the flow rate of water. The flow rate of water may be controlled by providing a dam or intake weir, but in small hydroelectric power generation, the water may be diverted from a natural river. In this case, the branched water channel is called an open channel or open channel, and there are various widths from several meters to several tens of meters. Such water flow is one of the most important observation data for river planning and management in hydropower generation.

  In order to measure the flow rate of a large-scale channel, it is necessary to obtain the water level, the cross-sectional shape of the channel, and the flow velocity distribution. In order to measure the flow velocity distribution over the entire cross section, it is essential to measure the flow velocity efficiently considering that the width of many first-class rivers is several tens to several hundred meters or more.

  The flow velocity measurement so far is basically point measurement, and in order to measure so as to cover a large-scale water channel, a great amount of labor proportional to the size of the water channel is required.

  There are propeller type velocimeters and electromagnetic velocimeters that can measure the flow velocity in one direction as point measurement devices. Or it becomes necessary to install many current meters. For this reason, there is a limit to the amount of data that can be acquired, and it takes time and labor to measure when moving, and when many are installed, the equipment cost increases and the labor of transportation increases. Furthermore, propeller-type velocimeters and electromagnetic velocimeters have a problem that proper measurement cannot be performed when the unsteadiness is strong, such as immediately after branching or merging of rivers.

  As another flow measuring device, a measuring device using an ultrasonic sensor and its method are known. This ultrasonic flow measurement device measures the flow velocity by receiving the reflected waves that are reflected by the ultrasonic waves oscillated in the water and reflected back to the suspended matter or bubbles in the water, and is mainly correlated with the Doppler method. The law is being used. In the market, a flow measuring device (ADCP: Acoustic Doppler Current Profiler) using the Doppler method is widely provided and used.

  As an example of ultrasonic flow measurement in a water channel, for example, Patent Document 1 includes at least a pair of ultrasonic sensors arranged on both banks of an open water channel, and transmits and receives between the ultrasonic sensors. An ultrasonic flow measurement device that measures the flow velocity in the ultrasonic propagation path based on the ultrasonic propagation time and calculates the flow rate in the open channel based on the measured value is disclosed (not the Doppler method). In Patent Document 1, the ultrasonic sensor can be moved up and down in the water depth direction, so that the flow velocity can be measured at the optimum measurement water depth position according to the optimum water depth.

JP 2002-162268 A

  However, in the case of the ultrasonic flow measuring device described in Patent Document 1, it is premised that the ultrasonic waves stably reach the receiving flow measuring device from the transmitting flow measuring device. However, there is a possibility that the ultrasonic waves cannot reach the opposite shore when the water channel becomes large. In addition, in order to control the ultrasonic sensors installed on both wall surfaces to always have the same height by using the lifting units on both wall surfaces of the water channel, large-scale equipment is required.

  In addition, the above ADCP flow measurement devices include a water surface installation type, a water bottom installation type, a mounting type on a towed body, etc., but all of them oscillate ultrasonic waves in the direction of the water depth, so measurement is difficult when the water depth is shallow. It is known that In particular, the towed type is difficult to measure when the flow scale of the water channel becomes large and the flow velocity becomes high, resulting in problems of stability and safety of the towed body. Therefore, the rivers where the ADCP flow measuring device can be used are limited.

  In addition, when ultrasonic waves are used, if the flow velocity is high, a predetermined resolution cannot be obtained unless the ultrasonic frequency is increased. However, since the reach of ultrasonic waves becomes shorter as the frequency becomes higher, there is a problem that it is difficult to measure a large-scale and large-flow water channel. Further, since the sampling frequency of AD conversion needs to be at least twice that of the ultrasonic wave according to Nyquist's theorem, the higher the frequency, the higher the speed and sensitivity of the receiving circuit, and the greater the signal processing load. For this reason, there is a problem that the measurement accuracy is sacrificed or the maximum flow rate that can be measured is limited.

  In view of such problems, the present invention has an object to provide an ultrasonic flow rate measuring method and a flow rate measuring apparatus capable of measuring the flow rate of the entire large-scale water channel with simple equipment.

  In order to solve the above-described problems, a typical configuration of the ultrasonic flow measurement method according to the present invention includes a water channel, a central part, a peripheral part from a wall surface or a bottom face from the central part, and a wall surface or a bottom face from a peripheral part. When the flow is divided into outer edges close to, the flow velocity distribution around the water channel is measured with ultrasonic waves, and the flow velocity distribution at the center of the water channel is interpolated using the measured flow velocity distribution to obtain the flow rate of the entire water channel. It is characterized by.

  According to the above configuration, the measurement range to be actually measured is only the peripheral portion, and the range in which the flow velocity is measured is narrower than the entire water channel, so that the number of flow velocity measurement points can be reduced. Therefore, even in a large-scale water channel, the distance that the ultrasonic wave should reach may be short, and measurement can be performed using a conventional ultrasonic sensor. In addition, since the distance that the ultrasonic wave should reach may be short, the frequency of the ultrasonic wave can be increased, and measurement can be performed even at a high flow rate.

  In the ultrasonic flow measurement method described above, the amount of change in the flow velocity from the wall surface toward the center portion is obtained, and a range in which the increment of the amount of change is equal to or less than a predetermined amount is preferably set as the peripheral portion. That is, when starting the flow measurement, first, a wide range of measurements is performed to set the peripheral part (calibration), and then the main measurement is performed on the peripheral part. Thereby, the peripheral part which is a data acquisition range can be set appropriately and objectively.

  In the ultrasonic flow rate measuring method described above, the amount of change in the flow velocity from the wall surface toward the central portion is obtained, and a stable flow range may be set as the central portion. That is, when starting the flow measurement, the central portion may be set instead of setting the peripheral portion. As a result, the flow velocity can be determined by interpolation without measuring a stable flow range, and the range over which the flow velocity is actually measured can be narrowed.

  The above-described ultrasonic flow rate measuring method may include an ultrasonic sensor arranged in the direction of the water surface and measure the water level in the water channel. Thereby, the height from the ultrasonic sensor to the water surface is known, and the water level is obtained together with the installation height of the ultrasonic sensor. From this water level and the known channel shape and dimensions, the cross-sectional area of the flowing water can be obtained, and the flow rate can be calculated from the measured flow velocity.

  The ultrasonic flow measurement method described above includes a reflection jig that reflects ultrasonic waves at a fixed distance from the ultrasonic sensor, measures the arrival time of the reflected wave of the ultrasonic wave, and calculates the sound velocity in water from the arrival time of the reflected wave. It is better to correct the flow velocity distribution.

  Thereby, it is possible to measure the speed of sound including environmental effects such as water temperature and water quality, and it is possible to sequentially reflect the change in the calibration value for measuring the above-mentioned flow velocity. Therefore, the flow velocity and flow rate of the water channel can be measured with high accuracy.

  In order to solve the above problems, another typical configuration of the present invention is an ultrasonic flow measurement method for measuring the flow rate of a water channel using an ultrasonic sensor, and has a large flow velocity distribution in the cross section of the water channel. Measure the flow velocity distribution in the turbulent flow region and the flow velocity distribution in the laminar flow region opposite to the turbulent flow region with respect to the ultrasonic sensor, and interpolate using the measured flow velocity distribution in the vicinity of the ultrasonic sensor. The flow rate of the whole waterway is calculated | required by this.

  According to the above configuration, the flow rate is measured in detail for a portion where the change amount of the flow rate is large, and the portion where the change amount is small is interpolated, so that the total flow rate can be known from the partial flow rate of the water channel. Therefore, since the range in which the flow velocity is measured becomes narrower than the entire water channel, the flow velocity measurement points can be reduced, the number of ultrasonic sensors can be reduced, and the data processing load can be reduced.

  In order to solve the above-described problems, a typical configuration of the flow rate measuring device according to the present invention includes a water channel, a central portion, a peripheral portion closer to the wall surface or the bottom surface than the central portion, and an outer edge closer to the wall surface or the bottom surface than the peripheral portion. A plurality of ultrasonic sensors that measure the flow velocity distribution from the central portion side toward the wall surface or bottom surface, and an interpolation unit that interpolates the flow velocity distribution in the central portion based on the flow velocity distribution measured by the ultrasonic sensor; It is characterized by providing.

  According to such a configuration, it is only necessary to measure the flow velocity only in the peripheral portion of the water channel, and the range in which the flow velocity is measured is narrower than the entire water channel, so that the flow rate can be measured with a small number of ultrasonic sensors. In the case of a large-scale water channel, it is preferable that the installation position of the device in the water channel to be measured is not a central part but a position closer to the wall surface. It is well known that the larger the water channel, the more stable the flow velocity in the central portion, and this is because the portion where the change in flow velocity is large, that is, the peripheral portion can be measured in detail.

  According to the present invention, it is possible to measure the flow rate of the entire large-scale water channel with a simple configuration.

It is a figure explaining schematic structure of a flow measurement device. It is sectional drawing of the direction orthogonal to the flow of a water channel. It is a schematic diagram of flow measurement in a water channel. It is a graph which shows the example of a measurement of flow velocity. It is a cross-sectional view of the flow of a water channel. It is a schematic diagram of an ultrasonic flow measuring device. It is a figure which shows the other structure of a flow measuring device. It is a figure explaining the other example of the flow measuring method. It is a figure explaining the structure of the flow measuring device used for the flow measuring method shown in FIG. It is a figure explaining the other example of the flow measuring method concerning the present invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a diagram illustrating a schematic configuration of a flow rate measuring device, FIG. 2 is a cross-sectional view in a direction orthogonal to the flow of the water channel, and FIG. 3 is a schematic diagram of flow rate measurement in the water channel in the present embodiment. The ultrasonic flow measurement method and the flow measurement device according to the present embodiment measure the flow rate of a water channel, and measure the flow rate in a water channel for intake of hydroelectric power generation as a representative example.

  A flow measuring device 200 shown in FIG. 1 has a plurality of ultrasonic sensors attached to a bowl-shaped sensor jig 202. As the ultrasonic sensor, a flow velocity detection sensor 204 arranged in the wall surface direction (horizontal direction), a water surface detection sensor 206 arranged in the water surface direction, and a correction sensor 208 are provided. In addition, a plate-like reflecting jig 210 is provided at a specific distance from the correction sensor 208 in the ultrasonic output direction of the correction sensor 208.

  The flow measuring device 200 is electrically connected to the control unit 250. The control unit 250 includes an operation unit 252 for operating measurement start and end, a recording unit 254 for recording ultrasonic sensor data, an interpolation unit 256 described later, and a display unit 258 for outputting processed data. It has. The processed data is not only displayed on the display unit 258 but may be stored as data in the recording unit 254 or transferred through a network. As a specific example, the control unit 250 can be configured using a computer and a control program.

  As shown in FIG. 2, in the present embodiment, the water in the water channel 100 is conceptually divided into three. That is, in the cross section of the water channel 100, the central portion 120 includes a center including the center of the water channel located in the center in the width direction and the water surface, the region near the wall surface or the bottom surface from the central portion 120, the peripheral portion 130, and the region extremely close to the wall surface or bottom surface Part 140.

  As shown in FIG. 3, the flow rate measuring device 200 having the above configuration is inserted from above a bridge or the like toward the center of the water channel 100, and is lowered until the lower end of the sensor jig 202 comes into contact with the bottom of the water channel 100. The flow rate measurement is performed with the flow velocity detection sensor 204 facing the wall surface 102.

  The sensor jig 202 is a jig for holding a plurality of ultrasonic sensors. For example, a steel pipe for pressure piping can be suitably used. When the ultrasonic sensors are arranged side by side, a horizontal member installed horizontally may be provided with respect to the main member installed vertically, and the ultrasonic sensor may be attached thereto.

  In this embodiment, the flow velocity detection sensors 204 are installed one by one toward the wall surfaces 102 on both sides of the water channel 100. The flow velocity detection sensor 204 measures the flow velocity of the water flowing through the water channel 100 using the Doppler method or the cross-correlation method. In order to measure the flow velocity, it is necessary to incline the output direction of the ultrasonic wave with respect to the flow. For example, it can be set to 15 ° from the direction orthogonal to the flow. As the flow velocity detection sensor 204, for example, a sensor provided with a 200 kHz vibrator can be suitably used.

  In this embodiment, the flow velocity detection sensor 204 measures the flow velocity distribution in the peripheral portion 130 of the water channel 100 with ultrasonic waves, and the flow velocity distribution in the central portion 120 of the water channel 100 is interpolated using the measured flow velocity distribution. The flow rate of the entire water channel 100 is obtained.

  FIG. 4 is a graph showing a measurement example of the flow velocity, where the horizontal axis is the distance (the center of the graph is the center of the water channel), and the vertical axis is the flow velocity. As shown in FIG. 4, the flow rate processes only a portion of the peripheral portion 130. Although the flow velocity of the outer edge portion 140 is actually measured, it is cut because the reflection from the wall surface 102 is too strong. The central part 120 does not measure the flow rate.

  The measured data is subjected to a predetermined calculation in the control unit 250 to acquire the flow velocity at each position. Then, the interpolation unit 256 interpolates the flow rate at the central portion 120 from the change in flow rate at each position in the peripheral portion 130. The interpolation may be linear approximation, but may be approximated by a quadratic or even-order function.

  It is known that the flow velocity of the outer edge portion 140 generally decreases near the wall surface. Therefore, the flow velocity (flow rate) of the outer edge portion 140 may be ignored. Furthermore, the flow velocity at the outer edge portion 140 may be extrapolated from the change in the flow velocity in the vicinity of the outer edge portion 140 among the changes in the flow velocity at the peripheral portion 130.

  According to the above configuration, the measurement range to be actually measured is only the peripheral portion 130, and the range in which the flow velocity is measured is narrower than that of the entire water channel 100. Therefore, the measurement points of the flow velocity can be reduced. Therefore, even in a large-scale water channel 100, the distance to which the ultrasonic wave should reach may be short, and measurement can be performed using a conventional ultrasonic sensor. In addition, since the distance that the ultrasonic wave should reach may be short, the frequency of the ultrasonic wave can be increased, and measurement can be performed even at a high flow rate.

  Here, the peripheral part 130 can be fixedly set as a ratio to the width of the water channel 100, for example. In addition, the flow rate detection sensor 204 is used to determine the amount of change in the flow velocity from the wall surface 102 toward the central portion 120, and the peripheral portion 130 can be a range in which the increment of the change amount is equal to or less than a predetermined amount. That is, when starting the flow rate measurement, first, a wide range of measurements may be performed to set the peripheral portion 130 (calibration), and then the peripheral portion 130 may be subjected to the main measurement. Thereby, the peripheral part 130 which is a data acquisition range can be set appropriately and objectively.

  Instead of setting the peripheral portion 130, the central portion 120 may be set. The central portion 120 can be fixedly set as a ratio to the width of the water channel 100, for example. Further, the flow rate detection sensor 204 is used to determine the amount of change in the flow velocity from the wall surface 102 toward the central portion 120, and a stable flow range (a range in which the amount of change or rate of change is a predetermined amount or less) is the central portion 120. Can be set. As a result, the flow velocity can be determined by interpolation without measuring a stable flow range, and the range over which the flow velocity is actually measured can be narrowed.

  The water surface detection sensor 206 is attached at an elevation angle so as to output ultrasonic waves from the underwater position of the sensor jig 202 toward the water surface. FIG. 5 is a cross section of the flow of the water channel. As shown in FIG. 5, the attachment angle of the water level detection sensor 206 can be set to 30 ° from the vertical, for example. As the water level detection sensor 206, for example, a sensor provided with a 300 kHz vibrator can be suitably used. Since the water level detection sensor 206 is used as a distance meter, the water level can be identified only by the level of the reflected wave.

  By knowing the height from the water level detection sensor 206 to the water level, the water level is obtained together with the installation height of the water level detection sensor 206. From this water level and the known channel shape and dimensions, the cross-sectional area of the flowing water can be obtained, and the flow rate can be calculated from the measured flow velocity. In the past, a measuring rod with a scale was inserted into the river to measure the water level, but by obtaining the water level as data using an ultrasonic sensor in this way, the data can be calculated in a lump. Processing becomes simple. Moreover, when measuring over a long time, transition of a water level can be grasped | ascertained and a more exact flow rate can be measured.

  Similarly, the correction sensor 208 transmits and receives ultrasonic waves to and from the reflection jig 210 attached to the sensor jig 202. Then, the correction sensor 208 outputs an ultrasonic pulse wave toward the reflection jig 210 and measures the arrival time of the reflected wave. Since the distance from the correction sensor 208 to the reflection jig 210 is known, the sound velocity in water can be calculated from the arrival time of the reflected wave, and the flow velocity distribution can be corrected. Thereby, it is possible to measure the speed of sound including environmental effects such as water temperature and water quality, and it is possible to sequentially reflect the change in the calibration value for measuring the above-mentioned flow velocity. Therefore, the flow velocity and flow rate of the water channel can be measured with high accuracy.

  The correction sensor 208 only needs to face the reflection surface of the reflection jig 210, and the attachment angle with respect to the sensor jig 202 may be arbitrary. For example, if both the correction sensor 208 and the reflection jig 210 are attached to the sensor jig 202, the output direction of the correction sensor 208 can be set parallel to the axial direction of the main material of the sensor jig 202. As the correction sensor 208, for example, a sensor provided with a 300 kHz vibrator can be suitably used.

  FIG. 6 shows another configuration of the flow rate measuring device 200, which is an example in which a plurality of sets of flow velocity detection sensors 204 are provided in the water depth direction (vertical direction). Even in this case, the flow velocity of the peripheral portion 130 is measured for each water depth, and the flow velocity distribution of the central portion 120 or the outer edge portion 140 is interpolated. As a result, the flow rate can be measured with a small number of ultrasonic sensors.

  FIG. 7 is a diagram showing another configuration of the flow rate measuring apparatus 200. In FIG. 7, a plurality of correction sensors 208 and reflecting jigs 210 are provided in the water depth direction (vertical direction). Thereby, even when the temperature distribution of the water flowing through the water channel 100 is large, the flow rate can be measured appropriately.

  FIG. 8 is a diagram for explaining another example of the flow rate measuring method. When the water channel 100 is a large-scale water channel, the installation position of the flow rate measuring device 200 is preferably a position closer to the wall surface 102 rather than the central portion 120. It is well known that the flow rate at the central portion 120 becomes more stable as the water channel becomes larger. If the water flow is set closer to the wall surface 102, the portion where the change in flow velocity is large, that is, the peripheral portion 130 is detailed. This is because it can be measured.

  Therefore, in FIG. 8, the flow measuring device 200 is installed in the vicinity of the wall surface 102 of the water channel 100, and only the peripheral portion 130 close to one wall surface 102 is measured. The measurement is performed on both sides of the water channel 100, but may be performed simultaneously using two flow rate measuring devices 200 or may be sequentially performed using one flow rate measuring device 200. In any case, since only the peripheral portion 130 of the wide water channel 100 is measured, the number of measurement points can be drastically reduced.

  FIG. 9 is a diagram for explaining the configuration of the flow rate measuring device used in the flow rate measuring method shown in FIG. In the method of FIG. 8, the flow rate is measured only in one direction with respect to the flow rate measuring device 200. Therefore, in the flow rate measuring device 200 shown in FIG. 9, the flow rate detection sensors 204 are not distributed to the left and right, and only one flow rate detection sensor 204 is provided at one water depth. Thereby, the number of ultrasonic sensors becomes necessary and sufficient, and highly accurate flow rate measurement can be performed with a small number of sensors.

  FIG. 10 is a diagram for explaining another example of the flow rate measuring method according to the present invention. In the above-described embodiment, the description has been made on the assumption that the laminar flow is a normal flow. However, depending on the state of the water channel 100, the water flow may be further disturbed.

  FIG. 10A shows an example in which the water channel 100 is bent and a vortex is generated. In this case, the peripheral portion 130 is set so that the vortex generation point 150 is included (the flow measuring device 200 is separated from the vortex generation point 150). Then, as can be seen from FIG. 10A, it can be seen that the peripheral portion 130 is not necessarily symmetrical on the left and right of the water channel 100.

  FIG. 10B is an example in which the flow is disturbed near the branch point of the water channel 100. In this case, the peripheral portion 130 is set so that the branch point 160 is included (the flow measuring device 200 is separated from the branch point).

  That is, the flow velocity distribution in the turbulent flow region having a large flow velocity distribution in the cross section of the water channel 100 and the flow velocity distribution in the laminar flow region on the side opposite to the turbulent flow region with respect to the flow detection sensor 204 are measured. By interpolating using the measured flow velocity distribution, the flow rate of the entire water channel 100 is obtained.

  In this way, by setting the peripheral portion 130 so that the measurement is performed reliably for the portion where the change amount of the flow velocity is large, the flow velocity can be measured at various locations, and the application range can be expanded. . Even in this case, since the range in which the flow velocity is measured is narrower than the entire water channel, the flow velocity measurement points can be reduced, the number of ultrasonic sensors can be reduced, and the data processing load can be reduced. it can.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  INDUSTRIAL APPLICABILITY The present invention can be used as an ultrasonic flow measurement method and a flow measurement device that measures the flow velocity distribution of a water channel with ultrasonic waves and measures the flow rate of the entire water channel.

DESCRIPTION OF SYMBOLS 100 ... Water channel 102 ... Wall surface 120 ... Center part 130 ... Peripheral part 140 ... Outer edge part 150 ... Vortex generation point 160 ... Branch point 200 ... Flow measuring device 202 ... Sensor jig 204 ... Flow velocity detection sensor 206 ... Water surface detection sensor 208 ... Correction Sensor 210 ... Reflecting jig 250 ... Control unit 252 ... Operation unit 254 ... Recording unit 256 ... Interpolation unit 258 ... Display unit

Claims (7)

When the water channel is divided into a central part, a peripheral part from the central part to the wall surface or the bottom surface, and an outer edge part closer to the wall surface or the bottom surface from the peripheral part,
Measure the flow velocity distribution in the periphery of the water channel with ultrasound,
An ultrasonic flow rate measuring method, wherein the flow rate distribution of the entire water channel is obtained by interpolating the flow rate distribution of the central part using the measured flow rate distribution of the peripheral part. Obtain the amount of change in flow velocity from the wall surface toward the central part,
The ultrasonic flow rate measuring method according to claim 1, wherein the peripheral portion is set up to a range in which the increment of the change amount is equal to or less than a predetermined amount. Obtain the amount of change in flow velocity from the wall surface toward the central part,
The ultrasonic flow rate measuring method according to claim 1, wherein a stable flow range is set as the central portion. It further includes an ultrasonic sensor arranged toward the water surface direction,
The ultrasonic flow rate measuring method according to claim 1, wherein the water level of the water channel is measured. Using a reflection jig that reflects ultrasonic waves at a certain distance from the ultrasonic sensor,
Measure the arrival time of the reflected wave of the ultrasonic wave,
Calculate the underwater sound speed from the arrival time of the reflected wave,
The ultrasonic flow rate measuring method according to claim 1, wherein the flow velocity distribution is corrected. An ultrasonic flow measurement method for measuring the flow rate of a water channel using an ultrasonic sensor,
Measure the flow velocity distribution of the turbulent flow region having a large flow velocity distribution in the cross section of the water channel, and the flow velocity distribution of the laminar flow region opposite to the turbulent flow region with respect to the ultrasonic sensor,
An ultrasonic flow rate measuring method, wherein the flow rate distribution in the vicinity of the ultrasonic sensor is interpolated using the measured flow rate distribution to determine the flow rate of the entire water channel. When dividing the waterway into a central part, a peripheral part from the wall surface or bottom surface from the central part, and an outer edge part close to the wall surface or bottom surface,
A plurality of ultrasonic sensors for measuring a flow velocity distribution from the central side toward the wall surface or bottom surface;
An flow rate measuring device comprising: an interpolation unit that interpolates the flow rate distribution at the center based on the flow rate distribution measured by the ultrasonic sensor.

Images