JP2005189186A - Flow-measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance measurement precision in the measurement of flow rate. <P>SOLUTION: This flow-measuring device is provided with a current meter for measuring the flow velocity of each of a plurality of divided areas set in the width direction of a measuring object, a water level gauge for measuring the water level of each divided area, and a calculating means for storing a section shape data showing the section shape of the measuring object; calculating the sectional area of each divided area, based on the water level obtained from the water level gauge and the section shape data; calculating the division flow rate of each divided area, based on the cross sectional area of each divided area and the flow velocity of each divided area obtained from the current meter; and calculating the total flow rate of the measuring object by adding each division flow rate together. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flow rate measuring device for measuring a flow rate of a measurement target.

For example, in Japanese Patent Application Laid-Open No. 02-083416, a plurality of flow velocity detectors are used to detect the flow velocity of each water surface in the width direction of the river, and a single water level transmitter is used to detect the water level of the river. A river flow rate monitoring system that automatically measures the flow rate of a river in real time based on an output signal (flow rate signal) of a flow velocity detector, an output signal (water level signal) of a water level transmitter, and cross-sectional shape data in a river water level measurement section is disclosed. ing. In this river flow monitoring system, the river is divided in the width direction according to the number of lines of flow velocity, and the sectional area (divided sectional area) of each divided area is obtained based on the water level and sectional shape data, and each divided sectional area is calculated. The total cross-sectional area is obtained by adding, and the flow rate is obtained by multiplying the total cross-sectional area by the flow velocity.
Japanese Patent Laid-Open No. 02-083416

  By the way, in the river flow rate monitoring system, there is a problem that the measurement accuracy at the time of low water level of the river is lowered. For example, when a low water level is reached, a river channel may be divided. In the above river flow monitoring system, only a single water level is detected by a single water level transmitter, so in such a divided state, based on the water level of one flow path detected by a single water level transmitter. If the flow rate of the other channel is obtained, an error due to a difference in water level occurs, and the measurement accuracy is significantly reduced. In addition, it is known that such a difference in the water level in the width direction of the river occurs not only in the state where the flow path is divided at the low water level but also in a curved portion of the river or a high water level.

  In addition, the divided cross-sectional area is obtained based on the water level and cross-sectional shape data. Depending on the cross-sectional shape of the river, the flow rate is measured because the river bottom is exposed due to the low water level even though water is flowing. However, there is a divided region where the measurement becomes impossible, and this causes a problem that the measurement accuracy is lowered.

  Furthermore, in the river flow monitoring system described above, in order to select each flow velocity signal in a time series in order by using a signal switching device and to load the flow velocity signal into the calculation processing portion, Deviation occurs. Since this shift in the capture timing becomes a shift in the measurement time of the flow velocity, there is a problem in that the measurement accuracy decreases as a result.

This invention is made | formed in view of such a situation, and aims at the following points.
(1) To improve measurement accuracy in flow rate measurement.
(2) Suppress fluctuations in measurement accuracy according to fluctuations in the water level of the measurement target.

  In order to achieve the above object, in the present invention, an anemometer that measures the flow velocity of each divided region set in the width direction of the measurement object, a water level meter that measures the water level of each divided region, and a cross section of the measurement object Stores cross-sectional shape data indicating the shape, calculates the cross-sectional area of each divided region based on the water level and cross-sectional shape data obtained from the water level meter, and obtains the cross-sectional area of each divided region and each divided region obtained from the anemometer A solution means is provided that includes a calculation means for obtaining a divided flow rate of each divided region based on the flow velocity of the divided areas and adding up the divided flow rates to obtain a total flow rate of the measurement object.

  According to the present invention, since the water level is measured for each divided region by the water level meter, for example, when the flow path is divided, the flow rate is measured with higher accuracy than when measuring the water level at one conventional location. can do.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the measurement target is a river.
FIG. 1 is a system configuration diagram of a flow rate measuring system using the flow rate measuring device according to the present embodiment. In FIG. 1, C is a flow meter, M is a processing device (communication means), K is a Web camera, N is the Internet, A is a management terminal, T1, T2,. This flow measuring device is composed of a flow meter C and a processing device M.

  The processing device M is provided between the flow meter C and the Internet N, and a Web camera K is connected thereto. The processing device M communicates with the flow meter C by a communication method compliant with RS-485, communicates with the Web camera K by a communication method compliant with Ethernet (registered trademark), and communicates with the TCP / IP protocol. Communicate with the management terminal A and user terminals T1, T2,... In addition to the communication function, the processing device M also has a data processing function for acquiring flow velocity data from the flow meter C and performing various processes.

  The Web camera K captures an image of a river (measurement site image) that is measured by the flow meter C, and transmits the measurement site image to the processing device M by a communication method compliant with Ethernet (registered trademark). Here, the processing device M has a Web server function and an FTP (File Transfer Protocol) server function as part of the communication function, and the flow rate data acquired from the flow meter C and the on-site image data acquired from the Web camera K. Are provided to the management terminal A and the user terminals T1, T2,... In the form of a Web page or FTP-compliant file.

  As is well known, the Internet N is a wide area communication network conforming to the TCP / IP protocol. The management terminal A is a computer that monitors the operation state of the flow meter C and the processing device M via the Internet N. The management terminal A accesses the processing device M, for example, provides the control data to the processing device M, acquires flow data, and acquires operation data indicating the operation state of the flow meter C and the processing device M, etc. I do. User terminals T1, T2,... Are computers operated by general users who need flow rate data, and obtain flow rate data by accessing the processing device M via the Internet N.

  FIG. 2 is a block diagram showing a functional configuration of the flow meter C. As shown in FIG. As shown in this figure, the flow meter C includes radio wave velocity meters F1 to F5, water level meters L1 to L5, RS-485 I / F1A to 1C, a CPU (Central Processing Unit) 2 (calculation means), a flash memory 3 and a shared memory. It consists of a memory 4 and the like. Among these components, the RS-485 I / F 1A to 1C, the CPU 2, the flash memory 3, and the shared memory 4 are accommodated in the apparatus main body H. That is, this flow meter C is composed of a total of five radio wave velocity meters F1 to F5 (velocity meter group), a total of five water level meters L1 to L5 (water level meter group), and an apparatus main body H.

  The radio wave velocimeters F1 to F5 utilize the phenomenon that the frequency of radio waves (measurement waves) irradiated to the water surface of the river is Doppler shifted by the flow velocity, that is, the Doppler effect. The flow velocity on the water surface is measured by detecting the frequency. Such radio wave anemometers F1 to F5 are attached to a bridge provided in a river, measure the flow velocities at a plurality of points set at predetermined intervals in the width direction of the river, and flow velocity signals indicating the measured values. Is transmitted to the apparatus main body H in a signal format conforming to RS-485.

  FIG. 3 is a schematic diagram showing each point (flow velocity measurement points P1 to P5) measured by the radio wave velocity meters F1 to F5 and each divided region corresponding to the flow velocity measurement points P1 to P5. As shown in FIG. 3, the radio wave velocimeters F1 to F5 are reflected from the flow velocity measurement points P1 to P5 by irradiating measurement waves to the flow velocity measurement points P1 to P5 preset in the width direction of the river. A wave is acquired, and the flow velocity on the water surface is measured based on the Doppler frequency of the reflected wave. The cross section of the river is divided into five regions (divided regions) in the width direction of the river by vertical lines corresponding to the flow velocity measurement points P1 to P5. Five water level meters L1 to L5 are provided corresponding to the radio wave velocity meters F1 to F5, measure the water level in each divided region, and form a water level signal indicating the measured value in accordance with RS-485. To the apparatus main body H.

  Subsequently, in the apparatus main body H, RS-485 I / F1A is an interface for performing communication based on the radio wave velocity meters F1 to F5 and RS-485 under the control of the CPU 2, and received from each of the radio wave velocity meters F1 to F5. The obtained flow velocity signal is output to the CPU 2. RS-485I / F1B is an interface that performs communication based on the above water level gauges L1 to L5 and RS-485 under the control of CPU2, and outputs the water level signal received from each water level gauge L1 to L5 to CPU2. To do.

  The CPU 2 calculates the flow rate of the river by calculating the flow velocity signal and the water level signal based on a predetermined calculation program, and outputs the flow rate value to the processing device M via the RS-485 I / F1C. The arithmetic processing by the CPU 2 will be described in detail in the operation description to be described later. As is well known, the flash memory 3 is an electrically rewritable memory, stores a water level-flow product table, an arithmetic program executed by the CPU 2, and the like. In response to a search request from the CPU 2, the water level-flow Specific flow data (cross-sectional area data) registered in the product table is output to the CPU 2.

  The water level-flow product table is cross-sectional shape data in this embodiment, and will be described in detail with reference to FIGS. As described above, the cross section of the river is divided into five divided areas in the width direction of the river by vertical lines, and the areas (cross-sectional areas) S1 to S5 of each divided area are areas through which water flows and are referred to as “flow products”. The flow products S1 to S5 are defined by the cross-sectional shape of the river and the water level as shown in FIG.

  Here, the cross-sectional shape of the river can be obtained by measurement in advance as a cross-section at the position where the flow velocity is measured by the radio wave velocimeters F1 to F5, so that the flow products S1 to S5 of each divided region depend on the water level of each divided region. Can be uniquely determined. As shown in the conceptual diagram of FIG. 4, the water level-flow product table is obtained by registering the product data indicating the products S1 to S5 corresponding to the water levels of the divided regions # 1 to # 5.

  The shared memory 4 is a memory that stores flow rate data that is a calculation result of the CPU 2 and various setting data necessary for the calculation process of the CPU 2. The RS-485 I / F 1C is an interface that mediates communication between the CPU 2 and the processing device M, and performs communication based on the RS-485 with the processing device M under the control of the CPU 2.

Next, the operation of the flow rate measuring apparatus configured as described above will be described.
First, the operation of the flow meter C will be described along the flowchart shown in FIG. This flowchart shows the main part processing procedure of the CPU 2.

  The CPU 2 is initialized first (step Sa), then acquires flow velocity data from each of the radio wave velocity meters F1 to F5 via the RS-485 I / F 1A (step Sb), and further via the RS-485 I / F 1B. Flow velocity data is acquired from each of the water level gauges L1 to L5 (step Sc). In the initialization process of step Sa, setting data is read from the shared memory 4 to the CPU 2.

  In the process of step Sb, the device numbers of the radio wave velocity meters F1 to F5 are sequentially specified in a predetermined order. For example, the radio wave velocity meter F1 → the radio wave velocity meter F2 → the radio wave velocity meter F3 → the radio wave velocity meter F4. → The flow velocity data corresponding to each of the divided areas # 1 to # 5 is sequentially acquired by the CPU 2 in the order of the radio wave velocity meter F5, and thus the flow velocity V1 to V5 corresponding to each of the divided areas # 1 to # 5 is specified to the CPU 2. Is done. Further, in the process of step Sc, the device numbers of the water level gauges L1 to L5 are sequentially specified in a predetermined order. For example, the water level gauge L1 → the water level gauge L2 → the water level gauge L3 → the water level gauge L4 → the water level gauge L5. The water level data corresponding to each of the divided areas # 1 to # 5 is sequentially acquired by the CPU 2 in order.

  Subsequently, the CPU 2 searches the water level-flow product table shown in FIG. 4 on the basis of the water level data Ri of the divided areas # 1 to # 5 acquired in the above step Sc, so that the divided areas # 1 to # 5 The flows S1i to S5i are specified. Here, the CPU 2 determines whether or not any of the flow velocity data of the divided areas # 1 to # 5 indicates that the flow velocity V1 to V5 indicates “0” (step Sd). In the case of “YES”, the water level data of the divided area located next to the divided area of the flow velocity data in which the flow velocities V1 to V5 indicate “0” are the flow velocity data in which the flow velocities V1 to V5 indicate “0”. Is applied to the water level data of the divided region (step Se), and if this determination is “NO”, the processing of step Se is omitted and the search processing of step Sf is executed.

  FIG. 6 is a diagram showing an example when there is flow rate data in which such flow rates V1 to V5 indicate “0”. That is, the radio wave velocity meters F1 to F5 irradiate the water surface of the river with the measurement wave and measure the water surface flow velocity V1 to V5 based on the Doppler frequency of the reflected wave of the measurement wave, as shown in FIG. When the water level of the river is low and the irradiation area of the measurement wave is the bottom of the river, there is no running water at the flow velocity measurement point P1 corresponding to the divided region # 1 and the flow velocity measurement point P5 corresponding to the divided region # 5. The flow velocities V1 and V5 measured for the divided areas # 1 and # 5 are “0”.

  In such a case, the CPU 2 applies the water level data and flow velocity data of the adjacent divided region # 2 to the water level data and flow velocity data of the divided region # 1 for the divided region # 1, and is adjacent to the divided region # 5. The water level data and flow velocity data of division area # 4 are applied to the water level data and flow velocity data of division area # 5. In addition, when the flow velocity data in which the flow velocity V1 to V5 indicates “0” exists, it may occur, for example, when any of the radio wave velocity meters F1 to F5 breaks down in addition to the low water level described above.

  Then, the CPU 2 searches the water level-flow product table based on the water level data applied to each of the divided regions # 1 to # 5, thereby obtaining the flow data corresponding to the water level of each of the divided regions # 1 to # 5. Obtain (step Sf). That is, the CPU 2 does not calculate the flow product of the divided regions # 1 to # 5 by calculation processing, but specifies the flow product of the divided regions # 1 to # 5 by searching the water level-flow product table. .

  Here, taking FIG. 6 as an example, if each water level data of the divided area # 2 and the divided area # 3 indicates the water level R2 in FIG. 4, the divided area # 1 includes the water level R2 of the adjacent divided area # 2. Apply. Similarly, when the divided area # 4 indicates the water level R1, the water level R1 of the adjacent divided area # 4 is applied to the divided area # 5. Then, the CPU 2 obtains the flow products S12, S22, S32 corresponding to the water level R2 for the divided areas # 1 to # 3 by searching the water level-flow product table, and for the divided areas # 4, # 5. The flow products S41 and S51 corresponding to the water level R1 are acquired.

  When the products S12, S22, S32, S41, and S51 of the divided regions # 1 to # 5 are identified in this way, the CPU 2 assigns each divided region # 1 to the products S12, S22, S32, S41, and S51. The flow rates A1 to A5 (segmented flow rates) of the divided areas # 1 to # 5 are calculated by multiplying the flow velocity V1 to V5 of # 5 (step Sg), and these segmented flow rates A1 to A5 are added together. To calculate the total flow rate As (step Sh). When the calculation of the total flow rate As is completed in this way, the CPU 2 returns the process to step Sb and starts the calculation process of the total flow rate As of the next cycle.

  According to such a flow meter C, when there is a flow velocity data in each of the divided areas # 1 to # 5 in which the flow velocities V1 to V5 indicate “0”, the divided areas are substituted. For example, by applying the water level data and flow velocity data of the adjacent divided area to the water level data and flow velocity data of the divided area of the flow velocity data indicating the flow velocity of “0”, the flooding is specified. The total flow rate As can be accurately calculated even when the radio wave velocimeters F1 to F5 are in a state incapable of measurement, such as when the radio wave velocimeters F1 to F5 fail.

  Moreover, since the water level of each flow velocity measurement point P1 to P5 is measured by a plurality of water level meters L1 to L5 corresponding to the radio wave velocity meters F1 to F5, for example, as shown in FIG. Even if the river is divided into two or more waterways due to the raised central part and there is a difference r in the water level of each waterway, each division is made according to the water level of each waterway. It is possible to accurately calculate the product of the regions # 1 to # 5.

Further, the flow velocity data of each of the radio wave velocity meters F1 to F5 is acquired by the CPU 2 at high speed via the RS-485 I / F1A, and the water level data of each of the water level meters L1 to L5 is acquired via the RS-485 I / F1B. The gap between the flow rate data and the water level data is very small. Therefore, it is possible to suppress a decrease in measurement accuracy due to the shift in the capture time.
That is, this flow meter C can measure the flow rate of the river with extremely high accuracy as compared with the prior art.

Next, the operation of the processing apparatus M will be described.
The processing device M periodically acquires the flow rate data stored in the shared memory 4 by accessing the CPU 2 via the I / F 1C, and acquires the field image data of the measurement field video from the Web camera K, Store in memory. When a measurement data provision request is received from the management terminal A and user terminals T1, T2,... Connected via the Internet N, the flow rate data and the field image data are provided to the management terminal A and user terminals T1, T2,. To do. This form of providing information is a form of a file based on a Web page or FTP.

  In addition, when the processing device M receives the calculation program of the CPU 2 and the rewrite request for the water level-flow product table stored in the flash memory 3 from the management terminal A, the processing device M receives the new calculation program, the water level-flow product via the I / F 1C. A table is provided to the CPU 2 to rewrite a conventional calculation program or water level-flow product table with a new calculation program or water level-flow product table.

  Since such a processing apparatus M has a communication function via the Internet N, maintenance and operation monitoring of the flow meter C can be performed from the remote management terminal A. Therefore, the convenience of maintenance and operation monitoring of the flow meter C is dramatically improved as compared with the conventional manual maintenance and operation monitoring, and the cost for maintenance and operation monitoring can be reduced. Further, since the flow rate information can be provided to the management terminal A and the user terminals T1, T2,... In the form of a file conforming to a general-purpose Web page or FTP as an Internet-related technology, the administrator or general user can obtain the flow rate information. Is very easy to obtain.

In addition, this invention is not limited to the said embodiment, For example, the following modifications can be considered.
(1) In the above embodiment, the five radio wave velocimeters F1 to F5 and the water level gauges L1 to L5 are connected to the apparatus main body H as described above. Since the specification is such that the water level meter can be connected, the number of radio wave velocimeters and water level meters, that is, the number of divided areas, can be appropriately changed according to the scale of the river.
(2) In the above embodiment, the five water level meters L1 to L5 are also provided corresponding to the five radio wave velocity meters F1 to F5. However, the number of the water level meters L1 to L5 is not necessarily limited to the radio wave velocity meter F1. It is not necessary to have the same number as ~ F5. The number of water level meters L1 to L5 may be smaller than the number of radio wave velocity meters F1 to F5.

1 is a system configuration diagram of a flow velocity measurement system using a flow rate measuring device according to an embodiment of the present invention. It is a block diagram which shows the principal part function structure of the measuring apparatus concerning one Embodiment of this invention. It is a schematic diagram which shows the flow velocity measurement points P1-P5 which each radio wave velocity meter F1-F5 measures in one Embodiment of this invention, and each division | segmentation area | region. It is a conceptual diagram of the water level-flow product table in one Embodiment of this invention. It is a flowchart which shows operation | movement of the flowmeter C in one Embodiment of this invention. It is a schematic diagram which shows the state of each flow velocity measurement point P1-P5 at the time of the low water level in one Embodiment of this invention. It is a schematic diagram which shows the division state of the flow path at the time of the low water level in one Embodiment of this invention.

Explanation of symbols

C ... Flow meter, M ... Processing device (communication means), K ... Web camera, N ... Internet, A ... Management terminal, T1, T2 ... User terminal, F1-F5 ... Radio current meter, L1-L5 ... Water level meter, 1A to 1C RS-485 I / F, 2 CPU (calculation means), 3 Flash memory, 4 Shared memory

Claims (7)

An anemometer that measures the flow velocity of each divided area set in the width direction of the measurement target,
A water level meter for measuring the water level in each of the divided regions;
Stores cross-sectional shape data indicating the cross-sectional shape of the measurement object, obtains a cross-sectional area of each divided region based on the water level obtained from the water level gauge and the cross-sectional shape data, the cross-sectional area of each divided region and the And calculating means for obtaining a divided flow rate of each divided region based on the flow velocity of each divided region obtained from an anemometer and adding the respective divided flow rates to obtain a total flow rate of a measurement object. Flow rate measuring device. The computing means obtains the cross-sectional area based on the water level of the divided area adjacent to the arbitrary divided area when the water level of the arbitrary divided area cannot be obtained from the water level meter. Flow measurement device.   The calculation means stores, as cross-sectional shape data, a water level-flow product table in which a plurality of cross-sectional area data indicating the cross-sectional area (flow product) of each divided region corresponding to the water level is registered for each divided region, and is obtained from the water level meter. The flow rate measuring device according to claim 1 or 2, wherein a cross-sectional area of each divided region is specified by searching a water level-flow product table based on the obtained water level.   The flow rate measuring device according to any one of claims 1 to 3, wherein a plurality of anemometers and water level meters are provided corresponding to each divided region.   The flow rate measuring apparatus according to claim 1, further comprising a communication unit that transmits the total flow rate calculated by the calculation unit to an external device via a communication line.   6. The flow rate measuring apparatus according to claim 5, wherein the communication means causes the calculation means to set the water level-flow product table when the cross-sectional shape data or the calculation program executed by the calculation means is received from the outside. The flow rate measuring device according to claim 5 or 6, wherein the communication means includes a Web server function and / or an FTP server function for providing the flow rate to an external device.

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