TWI230783B - Method and system of average flowing velocity measurement in river - Google Patents

Abstract

The present invention relates to a method and system of an average flowing velocity measurement in a river and, more particularly, to a system and method of an average flowing velocity measurement in a river abundant in silt. Two sound waves are transmitted from point A and point B of the river at the same time and are received by point B and point A respectively. The average flowing velocity between point A and point B is calculated according to the transmitting time of the sound waves. The present invention may further include a silt detecting device to measure the concentration of silt in the water as a basis to select suitable equipment.

Description

Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 1230783 A7 — B7____ V. Description of the Invention (1) Field of the Invention The present invention relates to a method and system for measuring the average flow velocity of river waters, especially to a river with mud and sand. Methods and systems for measuring average velocity in water. BACKGROUND OF THE INVENTION The river slopes in Taiwan are steep and the current is extremely difficult to observe. During heavy rains, the water flow is turbulent and river flows rise and fall rapidly, often causing severe disasters. 78% of the rainfall in the province was concentrated during the typhoon from May to October. Floods carried a large amount of sediment. Observations on the site were difficult, the instrument was easily lost and damaged, and personnel safety was a concern, making river flow measurement more difficult. However, even if the high-speed water flow during the flood period makes the on-site measurement difficult, data such as flow velocity are still important references for river improvement and water resource engineering planning and design, so it must be managed. The use of sound waves to detect the physical properties of water is an in-depth study, and there are many related studies, such as the use of sound waves to detect changes in the bottom of the ocean (Goff, 1999; Paige, 2000), and the search for certain fish schools or Structures (Volovov, 1999). The latest application is the use of two-dimensional underwater acoustic wave groups to monitor the movement of ships (submarines) in the sea (Yang Wenzhang, 1993; Chen Qifang, 1999). However, acoustic waves are generally used in marine engineering or ocean exploration, and rarely used in rivers. One of the reasons is that a single-point velocity or vertical velocity profile is required in the sea. Therefore, current commercial flow velocity measuring instruments are generally designed to measure single-point velocity or vertical velocity. In rivers, however, we are interested in flow. Therefore, in rivers, the average flow rate is 4LIU / 200101TW 1 pack --- (Please read the precautions on the back before filling this page) · Order L --- # This paper size applies to China National Standard (CNS) A4 specifications (210 X 297 mm) A7 1230783 B7 V. Description of the Invention (丄) It is the measurement focus, not the single-point velocity. (Please read the note on the back before filling this page.) Known technologies include many instruments that measure single-point flow velocity, such as the ARGONAUT-XR introduced by SONTEK, which can measure a maximum flow velocity of 6m / s, and ADV ( Acoustic Doppler Velocimeter) can measure a velocity of 0.5m / s within 250 meters. In addition, the company also launched ADP (Acoustic Doppler Profiler), which can measure a velocity of 10m / s in the sea within 500 meters. The company further combined ADV and ADP into a PC-ADP (Pulse-Coherent Acoustic Doppler Profile), which can only observe a distance of 12 meters, but the resolution is 1.6 cm. Other companies have similar products. The latest flow velocity measurement method applied to rivers printed by the Employees' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs is the use of Doppler ultrasonics to measure the vertical velocity profile of rivers (Lemmin & Rolland, 1997). This has been achieved to a certain extent. success. In conjunction with sound wave detection, Imran, Pafker & Pirmez proposed the theory of the relationship between sound waves and flow velocity and flow rate in 1999, while in China there are related theories proposed by Lu Zhaoyao from 1995 to 1997. The above measurement method uses the vertical resolution of an ultrasonic velocity profiler to measure the velocity profile in a river, and then uses Qiu's theory to calculate the flow. However, the above method not only has problems in theory and erection of equipment, the biggest problem is that it cannot overcome the effects of sediment in rivers. Another similar instrument is the SONIC FLOW introduced by Korea Changmin. This instrument uses ultrasonic waves to shoot vertically into the water, and then uses the Doppler effect to measure the average vertical flow velocity of the river. The maximum speed range of this instrument is 3m / s, but one of its shortcomings is that it cannot be used for more sediment content 4LIU / 200101TW 2 This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) Ministry of Economic Affairs Printed by the Intellectual Property Bureau Staff Consumer Cooperative 1230783 A7 B7 V. The River of Invention Description (3). In addition, the instrument is designed to be portable for use in the upper system, so it is suitable for small streams, but not for large rivers. Summary of the Invention The present invention relates to a method and system for measuring average flow velocity in river waters, and more particularly, to a method and system for measuring average flow velocity in river waters with mud and sand. In the present invention, a sound wave transmitter transmits a sound wave at the A terminal of the river water to be measured, and a sound wave receiver receives the sound wave at the B terminal; meanwhile, a sound wave is also transmitted at the B terminal, and is received at the A terminal. The two ends of A and B are located above and below the river waters. Record the time when two acoustic waves propagate in the river waters and find a time difference, so as to infer the average velocity of the water flow between the A and B ends. By integrating the velocity at different elevations, the flow in a section of the river waters can be obtained. The present invention may include a sediment content detector, and use the measured sediment content as a basis for selecting an appropriate measuring instrument. The acoustic wave transmitter and the acoustic wave receiver of the present invention can be the same device (dual-use for transmitting and receiving) to simplify the instrument. Acoustic transmitters and receivers can also be installed on a vertical bar to measure the velocity of flow at different elevations in a section of river waters. Brief Description of the Drawings Figure 1 shows the presenter's method for measuring the average velocity of river waters in the present invention. FIG. 2 is a schematic diagram of on-site measurement according to an embodiment of the present invention. FIG. 3 is a configuration diagram of a field measurement system according to an embodiment of the present invention. 4LIU / 200101TW 3 This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) ------- -------- r Order—ί ------- ( (Please read the notes on the back before filling this page) 1230783 A7 B7 V. Description of the invention (+) Figure 4 is a schematic diagram of the vertical bar of the embodiment of the present invention. Symbols of graphic elements indicate the printing of A, A, B, B, B at the Consumer Property Cooperative of the Intellectual Property Bureau of the Ministry of Economics. Measured end D. Channel width U! Measured flow velocity u2 between both ends of A and B. A ', B' both ends. Measured flow rate a. The angle between Sichuan and U2 301, 301, sonic generator 302, 302 'sonic transmitter 303, 303' sonic receiver 304, 304 'filter 305, 305' amplifier 306 data transmission group 307 microprocessor 308 Sediment content detector 309, 309 'Vertical bar Z 1 5 Z2 5 .....? Z7 Acoustic transmitter and receiver elevation (z coordinate) Ul, u2, ..., U7 Average velocity of different elevations (please (Read the precautions on the back before filling this page) Detailed description of the invention Figure 1 shows the flow chart of the method for measuring the average flow velocity of river waters according to the present invention. Step 101: First measure the sediment content and concentration in the river water to be measured. 4LIU / 200101TW 4 This paper is in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm) 1230783

Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of invention (5) Degree. In general, the presence of sediment is inevitable in river waters. In order to solve the difficulties of conventional techniques, the method for measuring the average flow velocity in river waters of the present invention includes a step of detecting sediment content. After grasping the sediment content in the river waters to be measured, it proceeds to step 102 ′ to select the sonic transmitter / receiver according to the sediment content and concentration. As the sediment in river water will reduce the acoustic wave amplitude, it is necessary to select an appropriate instrument in accordance with the sediment concentration. When a sound wave is transmitted in a medium, it is transmitted as a pressure wave, and the change of its pressure with distance is

Pr-Ps'f {r \ e ~ ar (1) where 6 is the pressure amplitude at the receiving end and is the pressure amplitude at the transmitting end 'is the energy consumed by the sound wave as it passes through the medium, indicating that the medium will absorb the energy of the sound wave, so a is Parameters of the medium. / (r) is the energy diffusion 'when the sound wave is transmitted, which can be regarded as a function of the geometric shape. For example, in a three-dimensional shape with no boundaries, outer) = Shi; and in a two-dimensional propagation pressure field, outer) = Shi; one-dimensional propagation depends on the shape of the propagation channel. The unit of sound wave amplitude is generally calculated in decibels (dB). The formula (1) is 201og1 () to obtain 20 log10 Pr = 20 log10 Ps + 20 log, 〇f (r)-20ar log10 e (2) The general microphone converts sound pressure into voltage 値 output, so formula (2) The sound pressure in medium is expressed by voltage. The formula for converting voltage to sound pressure is (y \ 201〇g10 | ^^ > ySPL ^ VL-SEN (3) 4LIU / 200101TW 5 This paper size is applicable to China National Standard (CNS) A4 (210 X 297 cm) (Li) Install -------- ^ Order L ------- (Please read the precautions on the back before filling out this page) A7! 23〇783 Β7 5. Description of the invention (k) in the air ， = 20 <; But in water, 々 = 1 this. Among them, SPL (sound pressure level) is obtained by subtracting the sensitivity (SEN) of the instrument itself from the voltage level (VL), and the acoustic energy level VL is Calculate VL = 20lo ^ 〇 ^ / fref from the following formula (4) Because the reference voltage Vref of SEN is IV, Vref = IV is also used in the calculation of formula (4). V in formula (4) is The transmitted or received sound wave voltage. SEN is the sensitivity of the instrument itself. The smaller the SEN 値, the higher the sensitivity of the instrument. The sensitivity of the transmitting and receiving underwater microphones is not necessarily the same. 201og1 () / (r) = // (r) and a = 20alog1 () e, the equation (2) can be rewritten as VLr = VLS + SENr-SENs + H (r) -〇cr (5) α system Is a medium parameter. The parameter represents the energy consumed in the medium when the sound wave passes through the medium; that is, the energy reduction rate of the sound wave through the water flow containing sediment. The relationship between α and the concentration of sediment M and the frequency of sound wave f is α = α (Μ , /), Α 値 at various sediment concentrations and acoustic frequencies needs to be obtained through a large number of indoor experiments. According to an embodiment of the present invention, the experimental results show that the concentrations M and α 値 are at a sound frequency of 5K and the frequency is fixed. The relationship becomes approximately linear. At a fixed concentration M, α 値 and the frequency of the sound wave are also approximately linear. After determining α 値, you can adjust the distance or choose an appropriate instrument based on the obtained 値 値. A microphone emits a 10V sound 4LIU / 200101TW 〈This paper size is applicable to China National Standard (CNS) A4 (21〇X 297 public love) (Please read the precautions on the back before filling this page) | Installation ---- ---- Order ----- 印 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs Printed by 1230783 A7 __ _____ ^^ B7 __ 5. Explanation of the Invention (")) Wave ' And assume its emission The sensitivity of the wave and the received sound wave are the same, both are _211.3dB. Then the sound size when the sound wave is transmitted to the receiving end is calculated according to formula (5). KLr = 20k) g (l0 / 1) + (_ 211.3) _ (- 211.3) + outside)-desire. Assume that the river water to be measured is a one-dimensional sound field, y (r): = +, and the river water contains trace sediment (α = 0 · 01). When the distance is r meters, the sound wave size is% = 20-211 · 3 + 211 · 3 + (0-2010 g) 100olr = 20-101 g g 001r. When the sound wave is transmitted by 100 meters from the transmitting end (r = 100), the size of the sound wave at the receiving end is -ldB. But the size of the sound wave actually received by the sound wave receiver needs to be deducted from the sensitivity ’, so the size of the sound wave received by the sound wave receiver is -ldB-(-211.3dB) = 20.3dB. If the sound wave receiver is located 200 meters away, the size of the received sound wave is 206.3dB. Therefore, according to the sediment content and concentration in river waters, instruments with appropriate sensitivity can be selected as the acoustic wave transmitter and acoustic wave receiver. After the sound wave transmitter / receiver is selected, step 103 is performed, and a sound wave having an appropriate frequency is formed by the sound wave generator. Since the preferred microwave frequency suitable for the present invention is between 500 Hz and 1 kHz, and different incident wavelengths and frequencies are required for different measurement conditions, a sound waveform generator is required to form a suitable sound wave. When a sound wave with an appropriate frequency is formed, the process proceeds to step 104, and the above-mentioned sound wave with an appropriate frequency is emitted from the A terminal. One of the embodiments of the present invention is the use of an underwater microphone to emit a sound wave of a selected frequency at the A end of river waters. However, the present invention is not limited to using an underwater microphone as a device for transmitting sound waves. Any other device that can be used to emit sound waves It is the intention of the present invention to guarantee 4LIU / 200101TW 7 This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) -------- r ^-L ------- ( (Please read the notes on the back before filling this page) 1230783 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the invention (8). Step 105: Receive the sound wave from the a terminal at the B terminal of the river water. Similarly, one of the embodiments of the present invention uses an underwater microphone as a device for receiving sound waves. However, the present invention is not limited to using an underwater microphone to receive sound waves. Any other device capable of receiving sound waves is intended by the present invention. The scope of protection. Step 106: Record the first time required for the sound wave to pass from the A terminal to the B terminal. Because the speed of sound wave transmission is extremely fast, the accuracy of the time recording device must be very accurate. The accuracy requirements will be described later. While performing steps 104, 105, and 106, steps 104a, 105a, and 106a can also be performed at once. In step 104a, a sound wave of an appropriate frequency is also transmitted at the B terminal. In step 105a, the sound wave from the B terminal is received at the A terminal. In step 106a, the second time required for the sound wave to travel from the B terminal to the A terminal is recorded. Similarly, one of the embodiments of the present invention uses an underwater microphone as a device for transmitting and receiving sound waves. However, the present invention is not limited to using an underwater microphone to transmit and receive sound waves. Any other device that can be used to transmit and receive sound waves All are within the scope of the present invention. In a specific embodiment of the present invention, the sound waves transmitted at both ends of A and B are of the same frequency and need to be transmitted simultaneously (that is, steps 104a, 105a, and 106a and steps 104, 105, and 106 need to be synchronized). Implementation) to avoid measurement errors. In step 107, the time difference Δ / transmitted by the sound waves at both ends of A and B is calculated from the first time and the second time, and the average flow velocity between the two ends of A and B is calculated based on it. After the measurement of the average flow velocity at a certain elevation between the two ends of A and B, enter 4LIU / 200101TW 〇 This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) I I ------ I ---------- Order --_------- (Please read the notes on the back before filling this page) 1230783 A7 B7 V. Description of the invention (q) Go to step 108 to determine whether The average velocity of all elevations between the two ends of A and B has been measured. Because different elevations in river water sections usually have velocity differences, if the average velocity of all elevations has not been measured, proceed to step 110, select one elevation and repeat the measurement steps; if the average velocity of all elevations has been measured, Then, step 109 is performed to calculate the cross-section flow according to the measured data. The calculation and explanation of the average velocity and discharge of river waters are as follows. Assume that the distance from the A end to the B end is R, the sound velocity is C, and u is the average flow velocity of the medium in the acoustic wave transmission path. When u and C are in the same direction (assuming that the current flows from end A to end B), the time required for sound waves to pass from end A to end B in the medium is (please read the precautions on the back before filling this page) • ΆΒ

R (6) and when the sound wave passes from B to A (counter current), the time required is

^ BA

R C — u (7) From (6) and (7) one half of the time difference is

At

^ AB —Xuan BA _ RU ~ RU 1 Η--r C2 \) (8) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 2 C2-Plant C2 Because the general river water flow is no faster than 10m / S, The speed of sound waves in water is about 1500m / s, so

C 4 · 4χ1 (Γ5. In general engineering science, this number is a negligible error. Therefore, using the characteristics of the acoustic wave in the time difference between the forward and reverse current, we can get

4LIU / 200101TW This paper size is applicable to Chinese National Standard (CNS) A4 (210 X 297 mm) 1230783 a7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the invention (L.) Among them, Δ / is a return signal At half of the receiving time, w is the average velocity of the medium flowing in the acoustic wave transmission path, and R is the linear distance from the transmitting end to the receiving end. Generally, the maximum width of the river water to be measured can reach 500 meters (at the estuary), and the smallest can also be 10 meters (irrigation channel). For the irrigation channel, the maximum flow velocity to be measured can reach 10 m / sec. Taking the irrigation channel as an example, the width and velocity are brought into equation (9), and we get = 0.0022 seconds. The accuracy of the general recorder can reach κΓ4 seconds, so in the case of [and R is very large, there is no problem in measuring with general instruments. But when w and R are small, the calculation of & will be difficult. In order to solve the above-mentioned difficulties, a preferred embodiment of the present invention is erected on both banks of the river water to be measured in the following manner. Fig. 2 is a schematic diagram of on-site measurement of a specific embodiment of the present invention. It can be known from equation (9) that when the flow velocity is constant, the farther the distance between the two ends of A and B is, the larger the 値 // is, and the smaller the error caused by the fixed signal interception time interval is. Therefore, as shown in Fig. 2, the embodiment of the present invention sets up two sets of instruments in a manner not parallel to the flow velocity, but avoids forming an angle of 90 degrees with the flow velocity direction. In Figure 2, the two ends of A and B are a transmitting / receiving group, and the two ends of A 'and B' are another transmitting / receiving group. The angle between the two groups of instruments is α, and the river waters to be measured The width between the two banks is D. During the measurement, each group will obtain the average velocity (A, B direction) and U2 (A ', B' direction) in the direction of the measurement line, and the combined velocity of U! And U2 is iRAsina. But this speed is not necessarily parallel to the two sides. In order to calculate the flow, 4LIU / 200101TW 10 (Please read the precautions on the back before filling this page) -Install -------- ^ Order ·! .-- # · 本Paper size applies Chinese National Standard (CNS) A4 (210 X 297 mm) 1230783 A7 B7 V. Description of invention ((υ (Please read the precautions on the back before filling this page) The concept of control volume can be controlled Check the triangle A′ΒΉ in Figure 2. Because there will be no outflow from the shore, the vertical flow of the A'B 'section is the flow of any section (such as B'H) in the river water. And the vertical The velocity component of the A'B 'section is UlSina, so the flow of river waters can be obtained by dividing UlSina with the A'B' section area. The advantage of this embodiment is that the measuring end can be selected by the researcher himself, without vertical It is located on both sides of the river water, so as to avoid the error of the vertical line. Another embodiment of the present invention can also use a set of instruments to measure the flow. The flow of the cross section of the river water can be expressed as the curve coordinate Q = [u-dA (10) where J is the cross-sectional area of vertical flow velocity. Generally measured At this time, because the flow velocity required to calculate the flow is parallel to the two banks, the direction of J can also be calculated by the average tangent direction of the two banks, and in the direction of the water flow is a straight line (usually the line connecting the midpoint of the river channel) (Consideration), the above formula can be used without vectors and the card-type coordinates can be written as Q = Wdydz where Y is the width of the river waters and Z is the depth of the water. If there is little change in the flow direction (X direction), Q can be written as the wisdom of the Ministry of Economy Printed by the Consumer Cooperative of the Property Bureau Q = \ V (iiudzdy) dx Ο. L 2 where I is the length of the river water area to be measured, π is the width of the river water area, A is the water depth, and W is the flow velocity in the X direction. Because the measurement must be at an angle with the main flow direction, the original (x, y, z) coordinates were changed to (χ / Α, ζ) coordinates, X; 4LIU / 200101TW 11 This paper scale applies Chinese national standards ( CNS) A4 specification (210 X 297 mm) 12307 ^ 3 A7 B7 V. The original X axis, h is the axis perpendicular to the original axis; c is rotated by a 0 angle counterclockwise. The measurement of the embodiment of the present invention is in the new Integrate in the yi direction under the coordinates Get a new flow Q 'Q' = \ t%: Jh \ dz (Kdyjhxdx '(12) where / 2 /, / ^ is the conversion coefficient from (X, y) coordinates to (heart force) coordinates, / ^ = 7 / 〇 is the evening, evening. The evening is the angle between the measurement line and the direction of the flow velocity. If the flow velocity at the (X, Jo) coordinate is (W, v), the flow velocity at the new coordinate is (M /, V /) , The relationship between

{W / = WV] = ucos θ-vsin θ (13) The measured flow velocity is actually v7, and the integral of V / is performed (formula (12)). Q 'is 1 PCQ + L ^-\ ζχιΘ Λ β = — I 丄 u cos ^-v sin 6dzdyx dxx (Please read the precautions on the back before filling out this page) One binding # Printed by the Ministry of Economic Affairs Intellectual Property Bureau Staff Consumer Cooperative

Qf = sinO— £ 0 + I ih ^ vdydzdx-cos6— [[+ L £ ^ udydzdx L L to fly L ϋ 1 = -Qsin Θ (14) because v is equal to j; the integral is zero and at the same time as (11) After comparison, the relationship between the obliquely measured flow rate 値 and the actual flow rate is Q'--Qcos Θ

Therefore, a single group of instruments can still get the flow of river water. However, the paper size of 4LIU / 200101TW is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm). 12 Printed by the Consumer Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs 1230783 A7 _ — ____ B7 V. The description of the invention is that the angle between the survey line and the velocity of the river water must be measured separately. The error in the regular channel is small in this embodiment. FIG. 3 is a configuration diagram of a field measurement system according to an embodiment of the present invention. The system for measuring the average flow velocity in river waters of the present invention includes sonic generators 301 and 301 '. Since the preferred microwave frequency suitable for the present invention is between 500 Hz and 1 kHz, and different incident wavelengths and frequencies are required for different measurement conditions, it is necessary to use the acoustic waveform generators 301 and 301 to drive into appropriate sound waves. . The present invention is not limited to including two acoustic wave transmitters 301 and 30Γ, and one acoustic wave transmitter 301 can be connected to the acoustic wave transmitters 302 and 302 'at both ends of a and B, respectively. The sound wave generators 301 and 301 'are connected to the sound wave transmitters 302 and 302, respectively, so as to transmit sound waves of appropriate waveforms from the A terminal to the B terminal. One of the embodiments of the present invention uses an underwater microphone as a device for transmitting sound waves. However, the present invention is not limited to using an underwater microphone to transmit sound waves. Any other device that can be used to transmit sound waves is within the scope of the present invention. . In addition, in a specific embodiment of the present invention, the sound wave transmitters 302 and 302 'transmit sound waves of the same frequency at the same time at both ends of A and B to avoid measurement errors. The system of the present invention further includes sound wave receivers 303 and 303 ', which respectively receive sound waves transmitted by the sound wave transmitters 302 and 302'. Similarly, one of the embodiments of the present invention uses an underwater microphone as a device for receiving sound waves. However, the present invention is not limited to using an underwater microphone to receive sound waves. Any other device that can receive sound waves is intended by the present invention. The norm of protection 4LIU / 200101TW 13 This paper size applies to China National Standard (CNS) A4 (210 X 297 public love) --- ^ -------- L ------- (Please read first Note on the back, please fill in this page again) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 1230783 A7 B7 V. Description of the invention (丨 +) It should be noted that 'for the accuracy of the measurement, the acoustic wave transmitter 302 of the invention The acoustic wave receiver 303 may be the same device; and the acoustic wave transmitter 302 and the acoustic wave receiver 303 ′ may also be the same device. That is, the sound wave transmitter 302 and the sound wave receiver 303 of the present invention can be a sound wave transmitting / receiving device of the same body; and the sound wave transmitter 302 'and the sound wave receiver 303 can also be a body of a transmitting and receiving body. Acoustic wave transmitting / receiving device, in order to avoid the error of acoustic wave transmission distance caused by the installation of the instrument, and achieve the purpose of streamlining the instrument. The system of the present invention may further include filters 304 and 304, which are connected to the acoustic receivers 303 and 303 ', respectively. The filters 304 and 304 are used to filter the sound waves received by the sound wave receivers 303 and 303 'to remove noise in the sound waves. The system of the present invention may further include amplifiers 305 and 305 'connected to filters 304 and 304', respectively. The amplifiers 305 and 305 'are used to amplify the sound waves filtered by the filters 304 and 304' to facilitate the measurement and judgment of the system. The system of the present invention includes a data transmission group 306 connected to the acoustic receivers 303 and 303 '. The data transmission group 306 wirelessly transmits the time data transmitted by the sound waves in the river waters to a remote workstation for the researchers at the remote site to conduct research. The system of the present invention further includes a microprocessor 307 connected to the data transmission group 306. The microprocessor 307 is responsible for receiving the acoustic wave transmission time data transmitted by the data transmission group 306, and performing the calculation of the flow velocity of the river water to be measured based on the acoustic wave transmission time data. The system of the present invention further includes a sediment content detector 308, which is connected to the data transmission group 306. The sediment content detector 308 detects the sediment concentration in the river water to be measured, and transmits the detection data to the Yuan 4LIU / 200101TW via the data transmission group 306. 14 This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297). Li) · Install -------- ^ Order L --- (Please read the precautions on the back before filling this page) # 1230783 A7

B7 V. Researchers of the invention description (\ 5) regard it as the basis for selecting the sound wave transmitter / receivers 302, 302 ', 303, 303'. FIG. 4 is a schematic diagram of a vertical bar according to an embodiment of the present invention. Since the flow velocity of river waters varies slightly according to the water depth, it is best to measure the flow velocity at different water depths to ensure the accuracy of the measurement. As shown in FIG. 4, the sound wave transmitters 302 and 302 ′ and the sound wave receivers 303 and 303 ′ are slidably arranged on the vertical bars 309 and 309 ′, among which the sound wave transmitters 302 and 302 and the sound wave receivers 303 and 303 The elevation (z coordinate) is controlled mechanically or manually. When the sound wave transmitters 302 and 302 ′ and the sound wave receivers 303 and 303 are both located at ζ :, the measured flow velocity is ^; when they are located at Z2, the measured flow velocity is ί; and so on. After measuring the average flow velocity at different elevations, integrate it to obtain the cross-sectional flow rate 2 Z itli. It should be noted that the present invention is not limited to measuring the average flow velocity of rivers, but can also be applied to lakes, reservoirs, and ponds. Measurement of the average flow velocity in other waters. The above detailed description of the preferred embodiments is used to more clearly describe the features and spirit of the present invention, but not to limit the scope of the present invention. The scope of the patentable scope of the present invention should be explained in the broadest sense according to the above description, and cover all possible equal changes and arrangements with equality.

4LIU / 200101TW 15 This paper size is applicable to China National Standard (CNS) A4 specification (21〇X 297) · Install -------- ^ Order L ------- Γ Read first read the back (Please note this page before completing this page) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs

Claims (1)

B8 C8 D8 Employee Consumption of Intellectual Property Bureau of the Ministry of Economic Affairs ^: Printed by the agency 1230783 VI. Patent application scope m Replacement page 2004/09/03 Case number 90112355. 1. A measurement of a river water between the A end and the B end A method of average flow velocity of one stream, wherein the B-end is benefiting from the downstream of the A-end, the method includes the following steps: measuring the sediment intake of one of the river waters; A sound wave and a sound wave transmitter of a second sound wave, and a sound wave receiver that receives the first sound wave and a sound wave of the second sound wave; the first sound wave is transmitted from the A terminal; the first sound wave is recorded to reach the river through the river waters One of the B-side first time; the second sound wave emitted by the B-side; recording the second time when the second sound wave reaches the A-side through the river waters; and 'from the first time and the second time Calculate the average velocity; wherein the first acoustic wave and a second acoustic wave are acoustic waves other than ultrasound. • 2. The method according to item 1 of the scope of patent application, wherein the frequency of the first sound wave is between 500 Hz and 1 kHz. 3. The method according to item 1 of the scope of patent application, wherein one of the better frequencies of the second acoustic wave is between 500 Hz and 1 kHz. 4. The method according to item 2. of the scope of patent application, wherein the frequency of the second sound wave is the same as the frequency of the first sound wave. 5. —A measure of the level of water flow between the A and B ends of a river. 4LIU / 200101TW 16 This paper size is applicable to China National Standard (CNS) A4 (210 X 297 public) B8 C8 D8 1230783 I. VI. Patent Application Replacement Page 2004/09/03 Case No. 90112355 The method of uniform flow velocity, wherein the B end is located downstream of the A end, the method includes the following steps:-measuring the river. Waters A sediment content; according to the sediment content, a sound wave transmitter that emits one sound wave and one second sound wave is selected, and one sound wave receiver receives the first sound wave and one sound wave; The first sound wave is transmitted from the A terminal and the second sound wave is transmitted from the B terminal at the same time; the first time when the first sound wave reaches the B terminal through the river waters is recorded, and the second sound wave passes through the river waters is recorded A first time to reach the A end; and a time difference is calculated from the first time and the second time, and the average flow velocity is calculated; wherein the first sound wave and a second sound wave system are non-ultrasonic waves. 6. · A system for measuring the average flow velocity of a river water area, including: measuring the sediment content of one river water area; the member of the Ministry of Economics and Intellectual Property Bureau X Consumption Co., Ltd. prints and launches a A sound wave transmitter of a first sound wave and a second sound wave, and a sound wave receiver that receives the first sound wave and one of the second sound wave; a sound wave generator forming the first sound wave and the second sound wave; a first A sonic transmitter connected to the sonic generator to emit the first sonic wave; a second sonic transmitter connected to the sonic generator to emit the second sonic wave; _4LIU / 200101TW__ __ This paper is dimensioned to the Chinese National Standard (CNS ) A4 specification (21〇X 297 MM) B8 1230783 one-to-one S5 VI. Patent application replacement page 2004/09/03 Case No. 90112355. A first sonic receiver to receive the first sonic wave; _ (please M first .Read the notes for reading δ again: a second sonic receiver to receive the second sonic wave; and a data transmission group, respectively to the first sonic receiver and the second sonic wave. Receive Connect, and transmit a time data of the first sound wave and the second sound wave in the river water to a remote workstation by wireless; wherein the first sound wave and a second sound wave are non-linear Ultrasound. 7. The system according to item 6 of the patent application, wherein the first sonic transmitter and the second receiver are the same device. 8. The system according to item 6 of the patent application, The second sonic transmitter and the first sonic receiver are the same device. 9. The system described in item 6 of the patent application, further includes a microprocessor connected to the data transmission group to process the data. Time data and average flow velocity calculation of a river water area 10. The system described in item 9 of the scope of patent application further includes a sediment content detector, which is connected to the microprocessor through the data transmission group to measure the river water area One is the content of sediment. Consumption of employees of the Intellectual Property Bureau of the Ministry of Economic Affairs ^: printed by the company • 11. The system described in item 10 of the scope of patent application, wherein the microprocessor is selected based on the content of sediment The acoustic wave transmitter and the acoustic wave receiver in the river waters. 12. The system described in item 6 of the scope of patent application, further comprising a filter, the first acoustic wave receiver and the second acoustic wave receiver, respectively. Connect, filter the first sound wave received by the first sound wave receiver and the second sound wave received by the second sound wave receiver, and remove a noise. _4LIU / 200101TW __18 This standard is suitable for China Standard (CNS) A4 specification (210 X 297 issued)-B8 C8 D8 1230783 =. VI. Patent Application Replacement Page 2004/09/03 Case No. 90112355. (Please M ^ Back V / Note before: 13. The system according to item 12 of the scope of patent application, further comprising an amplifier connected to the filter, the first sound wave and the second sound after the noise are removed are amplified. 14. The system according to item 6 of the scope of patent application, further comprising a vertical bar, wherein the first sonic transmitter is disposed on the vertical bar, and the vertical bar controls a vertical coordinate of one of the first sonic transmitters. . 15. The system according to item 6 of the scope of patent application, further comprising a vertical bar. The second sonic transmitter is disposed on the vertical bar, and the vertical bar controls the second sonic transmitter. A vertical coordinate. 1.6. The system according to item 6 of the patent application scope, further comprising a vertical bar, wherein the first sonic receiver is disposed on the vertical bar, and the vertical bar controls a vertical coordinate of one of the first sonic receivers. . 17. The system according to item 6 of the scope of patent application, further comprising a vertical bar, wherein the second sonic receiver is disposed on the vertical bar, and the vertical bar controls a vertical of one of the second sonic receivers. coordinate. Employees of the Intellectual Property Bureau of the Ministry of Economic Affairs and Consumer Affairs • Printed by the company 4LIU / 200101TW This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 g) 19