JP2010203865A - Ultrasonic type method and device for measuring flow rate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device of an ultrasonic type for measuring a flow rate which enable high accuracy measurement of the flow rate by measuring a flow velocity distribution and also by detecting the attitude of a sensor implement so as to compensate the flow velocity distribution. <P>SOLUTION: According to the typical constitution of this ultrasonic type method for measuring the flow rate, the sensor implement 202 is disposed in a water passage 100 and two or more ultrasonic sensors (flow velocity detecting sensors 204) for each one side of the wall surface 102 of the water passage 100 are disposed in the vertical direction of the sensor implement 202. While the flow velocity distribution is measured by the ultrasonic sensors, the position of the wall surface is measured thereby. From the position of the wall surface and the shape of the water passage, the attitude of the sensor implement is detected, and thereby the flow velocity distribution is compensated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ultrasonic flow rate measuring method and apparatus for measuring the flow velocity distribution of a water channel with ultrasonic waves and measuring the 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 acquire the water level, the cross-sectional shape of the channel, and the flow velocity distribution.

  As the measuring device for the point measurement, there are a propeller-type velocimeter, an electromagnetic velocimeter, an ultrasonic measurement device, and the like that can measure a unidirectional flow velocity. In any case, it is necessary to arrange the measurement device in water. The measuring device can be placed in the water by setting a scaffold and fixing a propeller type measuring device, installing a pedestal on the coast to fix an electromagnetic current meter, or sinking the ultrasonic measuring device to the bottom. It floats on the surface of the water.

  According to the ultrasonic flow velocity measuring apparatus described in Patent Document 1, a configuration in which an ultrasonic sensor is installed on the coast is described. In Patent Document 1, an elevating mechanism that elevates and lowers in the water depth direction is measured, and the flow rate distribution in the cross section of the open channel is measured by controlling the elevating mechanism so that the pair of ultrasonic sensors are at the same water depth position. It is possible to measure the flow rate with high accuracy.

  However, it is not always necessary to measure the flow rate, and it is often sufficient to measure it as necessary. On the other hand, there may be a plurality of points to be measured. Therefore, not a permanent flow measuring device but a portable portable device is also widely used. As a portable flow measuring device, for example, a configuration in which one or a plurality of current meters are attached to a bowl-shaped sensor jig and immersed in water is often used.

JP 2002-162268 A

  However, the portable flow rate measuring device has a problem that its position or posture is unstable as a price for portability. For example, when a bowl-shaped sensor jig to which an ultrasonic sensor is attached is suspended in water, even if the sensor jig is inclined in the width direction or the flow direction of the water channel, it is difficult for the operator to distinguish. If tilted, the flow rate measured by the ultrasonic sensor changes remarkably, resulting in a problem that the measurement accuracy is lowered.

  Further, when the water flow hits the ultrasonic sensor or the sensor jig, the sensor jig vibrates. In particular, vibration in the rotational direction (horizontal direction) can have a non-negligible effect on the measured flow velocity, and in this case as well, there is a problem that the measurement accuracy is lowered.

  For this reason, it is conceivable to acquire information on the position and orientation of the sensor jig. In order to obtain this information, it is possible to obtain information on the position and orientation of the sensor jig by installing a gyroscope, displacement meter, accelerometer, inclinometer, etc. on the sensor jig. A data collection device is required, which is not preferable from the viewpoint of labor and cost.

  Further, not only the flow velocity but also the water level change with time in measuring the flow rate. Therefore, conventionally, a measuring rod with a scale is inserted into the water channel, the water level is measured, and the cross-sectional area of the water is calculated together with the known cross-sectional shape of the water channel. .

  Therefore, the present invention provides an ultrasonic flow measuring method and a flow measuring device capable of measuring a flow velocity distribution, detecting the posture of a sensor jig, and correcting the flow velocity distribution to measure a flow rate with high accuracy. The purpose is that.

  In order to solve the above-mentioned problems, a typical configuration of the ultrasonic flow rate measuring method according to the present invention is that a sensor jig is disposed in a water channel, and 2 per side of the wall surface of the water channel in the vertical direction of the sensor jig. The above ultrasonic sensors are arranged, the flow velocity distribution is measured by the ultrasonic sensor, the position of the wall surface is measured, the posture of the sensor jig is detected based on the wall surface position and the shape of the water channel, and the flow velocity distribution is corrected. It is characterized by doing.

  According to the above configuration, the position and orientation information of the sensor jig can be easily obtained using the ultrasonic sensor for measuring the velocity distribution. Then, the flow rate distribution can be corrected using the posture information acquired in this way, and a highly accurate flow rate can be calculated.

  In another typical configuration of the ultrasonic flow rate measuring method according to the present invention, a sensor jig is arranged in the water channel, and one or more ultrasonic sensors are respectively provided on the sensor jig toward the wall surfaces on both sides of the water channel. And measuring the flow velocity distribution with an ultrasonic sensor, measuring the position of the wall surface, detecting rotational vibration of the sensor jig from the fluctuation of the wall surface position, and correcting the flow velocity distribution.

  According to the said structure, the rotational vibration of the sensor jig which arises in an ultrasonic sensor by the flow of water can be easily obtained using the ultrasonic sensor for measuring speed distribution. Then, it is possible to calculate the flow rate with high accuracy by eliminating the influence of rotational vibration.

  Another typical configuration of the ultrasonic flow rate measuring method according to the present invention is that a sensor jig is arranged in the water channel, and two or more of the sensor jig are directed to the bottom surface of the water channel from different angles or different heights. An ultrasonic sensor is arranged, the flow velocity distribution is measured by the ultrasonic sensor, the position of the bottom surface is measured, and the tilt angle in the flow direction of the sensor jig is detected from the position of the bottom surface measured by two or more ultrasonic sensors. The flow velocity distribution is corrected.

  According to the said structure, the inclination to the flow direction of a sensor jig can be detected easily. The flow rate distribution can be corrected using the gradient of the flow direction acquired in this way, and a highly accurate flow rate can be calculated.

  An ultrasonic sensor arranged toward the water surface direction may be further provided, and the water level of the water channel may be measured by the ultrasonic sensor. 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, it is possible to determine the cross-sectional area of the flowing water, and the flow rate can be calculated from the measured flow velocity.

  Furthermore, a reflection jig that reflects ultrasonic waves at a certain distance from the ultrasonic sensor is arranged, the arrival time of the reflected wave of the ultrasonic wave is measured using the reflection jig, and the sound speed in water is calculated from the arrival time of the reflected wave. It may be calculated 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, a typical configuration of the flow rate measuring device according to the present invention includes a sensor jig installed near the center of the water channel, and two or more sensor jigs facing the wall surface or bottom surface of the water channel. Detects the posture of the sensor jig based on the placed ultrasonic sensor, the control unit that measures the flow velocity distribution of the water channel and the position of the wall surface or the bottom surface using the ultrasonic sensor, and the position of the wall surface or the bottom surface and the shape of the water channel. And a correction unit that corrects the flow velocity distribution.

  According to such a configuration, it is possible to detect the attitude of the sensor jig in the water channel using the ultrasonic sensor for measuring the velocity distribution, and to correct the error in the flow velocity distribution based on the attitude of the sensor jig. And a more accurate flow rate can be calculated.

  According to the present invention, there is provided an ultrasonic flow measuring method and a flow measuring device capable of measuring a flow velocity distribution, detecting the attitude of a sensor jig, and correcting the flow velocity distribution to measure a flow rate with high accuracy. can do.

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 schematic diagram which shows the attitude | position of a sensor jig, and a measurement result example. It is a figure which shows the other structure of a flow measuring device. It is a schematic diagram of flow measurement in a water channel. It is a figure which shows the other structure of a flow measuring device.

  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. 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 plurality of flow velocity detection sensors 204 arranged in the wall surface direction (horizontal direction) are provided.

  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, and a display unit 258 for outputting processed data. 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 FIGS. 2 and 3, the flow rate measuring device 200 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 contacts the bottom surface 104 of the water channel 100. . The orientation of the sensor jig 202 is determined so that the flow velocity detection sensors 204 on both sides face the left and right wall surfaces 102, respectively. Further, at this time, the ultrasonic wave transmitted from the flow velocity detection sensor 204 is installed so as to face upstream as shown in FIG. In this state, an ultrasonic wave is oscillated from the flow velocity detection sensor 204, a reflected wave is received, and a flow velocity distribution measurement is performed.

  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 the present embodiment, the flow velocity detection sensor 204 has two or more flow velocity detection sensors 204 arranged on one side of the wall surface of the water channel 100 in the vertical direction of the sensor jig 202. In FIG. 1, six (six steps) flow velocity detection sensors 204 are arranged on one side. 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.

  The measured data is subjected to a predetermined calculation in the control unit 250 to acquire the flow velocity at each position. For the flow rate, a Doppler method or a cross-correlation method can be used.

  FIG. 4 is a graph showing a measurement example of the flow velocity, where the horizontal axis is the position (the center of the graph is the center of the water channel), and the vertical axis is the flow velocity. In the vicinity of the wall surface 102, the intensity of the reflected wave of the ultrasonic wave becomes extremely strong, so that the reliability of the flow velocity distribution data is low. Therefore, normally, data near the wall surface 102 is cut, and data as shown in FIG. 4 is acquired.

  FIG. 5 is a schematic diagram showing the posture of the sensor jig 202 and an example of measurement results. As shown in FIG. 5, when the sensor jig 202 is inclined in the width direction of the water channel 100 from the vertical direction, the flow velocity distribution is distorted. It is well known that the flow rate of water flowing through the water channel 100 increases as the distance from the wall surface or bottom surface increases. Therefore, when the sensor jig 202 is tilted, the ultrasonic scanning line on the opposite side to the tilted direction approaches the water surface 106, so that the flow velocity distribution tends to become faster.

  However, when the sensor jig 202 is tilted in this way, the distance to the wall surface 102 on the opposite side to the tilted direction becomes longer. For this reason, it can be acquired as data that the sensor jig 202 is tilted. Since the shape of the water channel 100 is known, the posture of the sensor jig 202 can be detected based on the position of the wall surface 102 and the shape of the water channel 100, and the flow velocity distribution can be corrected based on this posture information.

  Here, even if the flow velocity detection sensor 204 is a pair (one stage), if it is tilted, a difference occurs in the distance to the left and right wall surfaces 102. However, in the case of one stage, it cannot be distinguished from the case where the installation position of the sensor jig 202 is deviated from the center of the water channel 100. Therefore, it is preferable to provide at least two (two stages) flow velocity detection sensors 204 in the vertical direction of the sensor jig 202.

  According to the above configuration, the position and orientation information of the sensor jig 202 can be easily obtained using the flow velocity detection sensor 204 for measuring the velocity distribution. Then, the flow rate distribution can be corrected using the posture information acquired in this way, and a highly accurate flow rate can be calculated.

  Further, since the sensor jig 202 is inserted into the water flow, Karman vortices are generated on the downstream side of the sensor jig 202 and the flow velocity detection sensor 204, and rotational vibration is started as a whole. When the sensor jig 202 rotates and vibrates, the angle of the flow velocity detection sensor 204 with respect to the water flow changes, so that the flow velocity distribution to be measured is distorted. As described above, the scanning line of the flow velocity detection sensor 204 has an angle with respect to the flow, but when the angle becomes shallow (rotates in a direction orthogonal to the flow), the flow velocity is detected low. In addition, since the flow measuring device 200 is a long device of about 10 m, there is a risk that the portability may be lost if the flow measuring device 200 is rigid enough not to be twisted by the water flow.

  However, as described above, the sensor jig 202 is arranged at the approximate center of the water channel 100, and the flow velocity detection sensors 204 are arranged toward the wall surfaces 102 on both sides of the water channel 100. When the rotation angle as the center changes, the distance to the wall surface 102 changes. Therefore, by continuously measuring the position of the wall surface 102 when measuring the flow velocity distribution, the rotational vibration of the sensor jig 202 is detected from the change in the position of the wall surface 102, and the flow velocity distribution is corrected based on this posture information. be able to.

  According to the above configuration, the rotational vibration of the sensor jig 202 generated in the flow velocity detection sensor 204 due to the flow of water can be easily obtained using the flow velocity detection sensor 204 for measuring the velocity distribution. Then, it is possible to calculate the flow rate with high accuracy by eliminating the influence of rotational vibration.

  Furthermore, when the sensor jig 202 is arranged in the water channel, it is conceivable that the sensor jig 202 is installed in a rotational direction with respect to a predetermined installation direction. However, even in such a case, as described above, the sensor jig 202 is disposed at the approximate center of the water channel 100, and the flow velocity detection sensors 204 are disposed toward the wall surfaces 102 on both sides of the water channel 100. It can be acquired as data that the sensor jig 202 is rotating due to the difference between the left and right distances. As described above, since the shape of the water channel 100 is known, the posture of the sensor jig 202 can be detected based on the position of the wall surface 102 and the shape of the water channel 100, and the flow velocity distribution can be corrected based on this posture information. .

  It is also conceivable that the flow velocity detection sensor 204 in a part of the stage rotates depending on a change in the vertical velocity of the water flow. Even in such a case, it can be acquired as data that a part of the flow velocity detection sensor 204 is rotating from the difference between the left and right distances to the wall surface 102. Since the shape of the water channel 100 is known, the posture of the flow velocity detection sensor 204 can be detected based on the position of the wall surface 102 and the shape of the water channel 100, and the flow velocity distribution can be corrected based on this posture information.

  According to the above configuration, by using the flow velocity detection sensor 204 for measuring the velocity distribution, the position and orientation information at the time of installation of the sensor jig 202 and the deviation of a part of the flow velocity detection sensor 204 after installation can be easily detected. Can also be obtained. Then, the flow rate distribution can be corrected using the posture information acquired in this way, and a highly accurate flow rate can be calculated.

  FIG. 6 is a diagram showing another configuration of the flow rate measuring device 200, and FIG. 7 is a schematic diagram of flow rate measurement in a water channel.

  A flow rate measuring apparatus 200 shown in FIG. 6 is an example in which the sensor jig 202 includes a water surface detection sensor 206, a correction sensor 208, and bottom surface detection sensors 212a and 212b arranged in the direction of the water surface 106. . 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 water surface detection sensor 206 is attached at an elevation angle so as to output an ultrasonic wave from the underwater position of the sensor jig 202 toward the water surface 106. Further, the water surface detection sensor 206 is disposed with respect to the sensor jig 202, for example, in the flow direction (which may be either upstream or downstream). As shown in FIG. 7, the attachment angle of the water surface 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 surface detection sensor 206 is used as a distance meter, the water surface 106 can be identified only by the intensity of the reflected wave.

  By knowing the height from the water level detection sensor 206 to the water level 106, 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.

  In FIG. 6, one set of the correction sensor and the reflection jig 210 are provided, but the present invention is not limited to this, and a plurality of sets may be 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.

  The bottom surface detection sensors 212a and 212b are installed at different heights of the sensor jig 202, and are arranged to face the bottom surface of the water channel 100 at different angles. Further, the bottom surface detection sensors 212a and 212b are arranged, for example, in the flow direction (either upstream or downstream) with respect to the sensor jig 202. Both bottom surface detection sensors 212 a and 212 b measure the position of the bottom surface 104. As examples of different angles, the bottom surface detection sensor 212a is disposed at an angle of 30 ° from the vertical direction, and the bottom surface detection sensor 212b is disposed at an angle of 15 ° from the vertical direction. As the bottom surface detection sensors 212a and 212b, for example, those provided with a vibrator of 300 kHz can be suitably used.

  Thus, when the position of the bottom surface 104 (distance to the bottom surface 104) is measured by two ultrasonic sensors, the mounting position of each sensor (the height from the lower end of the sensor jig 202) is known. The inclination angle of the flow direction of the sensor jig 202 with respect to can be detected, the flow velocity distribution can be corrected based on this posture information, and a more accurate flow rate can be calculated.

  FIG. 8 is a diagram showing another configuration of the flow rate measuring device 200. The flow measuring device 200 shown in FIG. 8 further has a plurality of water level detection sensors 206a and 206b arranged in the direction of the water level 106. The water surface detection sensors 206a and 206b are installed at different heights of the sensor jig 202, and are arranged facing the water surface 106 at different angles. Further, the water level detection sensors 206a and 206b are arranged, for example, in the flow direction (which may be either upstream or downstream) with respect to the sensor jig 202. Both of the water level detection sensors 206 a and 206 b measure the position of the water level 106. As an example of different angles, the water surface detection sensor 206a is arranged at an angle of 30 ° from the vertical direction, and 206b is arranged at an angle of 15 ° from the vertical direction. As the water surface detection sensors 206a and 206b, for example, those having a 300 kHz vibrator can be suitably used.

  Although the bottom surface detection sensors 212a and 212b can determine the inclination of the flow direction from the bottom surface 104 of the water channel 100, the bottom surface 104 is not necessarily flat. On the other hand, if the water surface 106 is not violently disturbed, it generates a horizontal surface, and even if it is disturbed to some extent, the horizontal surface can be obtained by averaging the positions measured for a while (predetermined time: several seconds to several minutes). . Thus, the inclination of the flow direction can also be detected by using the water surface 106 as a reference, the flow velocity distribution can be corrected based on this posture information, and a highly accurate flow rate can be calculated.

  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 using ultrasonic waves and measures the flow rate of the entire water channel.

DESCRIPTION OF SYMBOLS 100 ... Water channel 102 ... Wall surface 104 ... Bottom 105 ... Flow direction 106 ... Water surface 120 ... Center part 130 ... Peripheral part 140 ... Outer edge part 150 ... Eddy point 160 ... Branch point 200 ... Flow measuring device 202 ... Sensor jig 204 ... Flow velocity detection Sensor 206 ... Water surface detection sensors 206a and 206b ... Water surface detection sensor 208 ... Correction sensor 210 ... Reflecting jigs 212a and 212b ... Bottom surface detection sensor 250 ... Control unit 252 ... Operation unit 254 ... Recording unit 258 ... Display unit

Claims (6)

Place the sensor jig in the waterway,
Two or more ultrasonic sensors are arranged on one side of the wall surface of the water channel in the vertical direction of the sensor jig,
With the ultrasonic sensor, the flow velocity distribution is measured, and the position of the wall surface is measured.
An ultrasonic flow rate measuring method, comprising: detecting an attitude of the sensor jig based on a position of the wall surface and a shape of the water channel and correcting the flow velocity distribution. Place the sensor jig in the waterway,
One or more ultrasonic sensors are arranged on the sensor jig toward the wall surfaces on both sides of the water channel,
With the ultrasonic sensor, the flow velocity distribution is measured, and the position of the wall surface is measured.
An ultrasonic flow rate measuring method, wherein rotational vibration of the sensor jig is detected from a change in the position of the wall surface, and the flow velocity distribution is corrected. Place the sensor jig in the waterway,
Two or more ultrasonic sensors facing the bottom surface of the water channel from different angles or different heights are arranged on the sensor jig,
With the ultrasonic sensor, the flow velocity distribution is measured, and the position of the bottom surface is measured,
An ultrasonic flow rate measuring method, wherein an inclination angle in a flow direction of the sensor jig is detected from a position of a bottom surface measured by the two or more ultrasonic sensors, and the flow velocity distribution is corrected. It further includes an ultrasonic sensor arranged toward the water surface direction,
The ultrasonic flow rate measuring method according to any one of claims 1 to 3, wherein the water level of the water channel is measured by the ultrasonic sensor. A reflection jig that reflects ultrasonic waves at a certain distance from the ultrasonic sensor is arranged,
Measure the arrival time of the reflected wave of the ultrasonic wave using the reflection jig,
Calculate the underwater sound speed from the arrival time of the reflected wave,
The ultrasonic flow rate measuring method according to any one of claims 1 to 3, wherein the flow velocity distribution is corrected. A sensor jig installed near the center of the waterway,
Two or more ultrasonic sensors arranged on the sensor jig toward the wall surface or bottom surface of the water channel,
A control unit for measuring the flow velocity distribution of the water channel and the position of the wall surface or the bottom surface using the ultrasonic sensor;
A flow rate measuring device comprising: a correction unit that detects the posture of the sensor jig based on the position of the wall surface or the bottom surface and the shape of the water channel, and corrects the flow velocity distribution.

Images