JP7449788B2 - Sediment flow meter and water intake control device for hydroelectric power plants - Google Patents

Description

The present invention relates to a quicksand amount measuring device and a water intake control device for a hydroelectric power plant.

In a run-of-river hydroelectric power plant, river water is sent to a penstock through an intake sluice gate, a settling basin, etc. The water that falls through the penstock rotates a water wheel and drives a generator.
Rivers are mixed with quicksand, and if a large amount of this quicksand enters a run-of-river hydroelectric power plant through a water intake, there is a risk of damaging the power plant's equipment. Therefore, for example, when the river water level is measured and the measured value is above a threshold value, it is estimated that a predetermined amount of quicksand is present, and the water intake sluice gate is closed to stop power generation.

Note that Patent Document 1 proposes a particle size determination device that arranges a piezoelectric sensor in a river and determines the particle size of river bedload based on an output signal detected by the piezoelectric sensor. This device makes it possible to measure the particle size of bed load flowing into a river and the distribution of bed load flowing at a given time.

Furthermore, Patent Document 2 proposes a particle size distribution estimation device that estimates the particle size (mass) of quicksand based on a signal detected by the accelerometer when quicksand collides with an accelerometer placed in a river. ing.

In Patent Document 3, an FBG (fiber Bragg grating) sensor is placed in a river, and an FBG analyzer detects the amount of strain caused by the collision of soil particles based on an optical signal of the Bragg wavelength outputted by the sensor, and the amount of strain is measured by an FBG analyzer. Based on this, the soil particle management and monitoring device determines the particle size of soil particles and the amount of sediment.

In Patent Document 4, a turbidity meter is placed in a river, and when the intake sluice gate is open and the turbidity exceeds the turbidity upper limit, the intake sluice gate is closed and the water intake sluice gate is closed. It has been proposed for a water intake control device for a run-of-river hydroelectric power plant that opens the intake sluice gate when the turbidity falls below the turbidity lower limit when the water is closed.

Japanese Patent Application Publication No. 2018-119792 Patent No. 4514730 Japanese Patent Application Publication No. 2010-276343 Japanese Patent Application Publication No. 2006-37354

In many run-of-river hydroelectric power plants, power generation is stopped based on the water level of a dam water level gauge that measures the water level of a river, or the turbidity value disclosed in Patent Document 4.
However, for example, when using the river water level as a standard, the amount of quicksand flowing into the river itself is unknown, so even though the river water level is actually in a state of quicksand that does not require power generation to be stopped, the river water level is The power plant may be shut down because it is within the range where it should be shut down. Another problem is that even though the power plant is in a state of quicksand that would require it to be shut down, it has restarted power generation because the water level of the river is within the range where it should. If the amount of quicksand is known, it can be expected to improve the accuracy of when to stop and restart power generation.

Patent Document 1 and Patent Document 2 measure the particle size of bed bed or quicksand, its distribution, etc., and do not aim at measuring the amount of quicksand, and do not disclose the measurement of the amount of quicksand. Not yet.

In the soil particle management/monitoring device of Patent Document 3, information on the basic flow velocity including the flow rate, width, slope, and roughness coefficient of the river is set in advance, and information on the collision angle, collision position, and collision with the FBG sensor according to the basic flow velocity is set in advance. The velocity probability information and the Salutation kinetic theory information are stored in the storage unit. For this reason, in Patent Document 3, it is necessary to set and input basic flow velocity information including the flow rate, width, slope, and roughness coefficient of the river for each river, which lacks versatility.

The purpose of the present invention is to solve the above-mentioned problems and to provide a sediment flow meter and a water intake control device for a hydroelectric power plant that are versatile and capable of detecting the flow sand amount in any river. be.

In order to solve the above problems, the quicksand amount measuring device of the present invention has an accelerometer that outputs a detection signal representing the magnitude of impact with quicksand flowing in a river, and an accelerometer that outputs a detection signal representing the magnitude of impact with quicksand flowing in a river, and , a database that has a plurality of combinations in which the integral value of acceleration per unit time and the amount of quicksand per unit time are associated, and the waveform of the detection signal is converted into an absolute value and an envelope connecting the waveforms is calculated. a first calculation unit that calculates a time integral value of a region surrounded by the envelope and a predetermined time frame; and a second calculation unit that calculates an integral value of acceleration per unit time based on the time integral value. The apparatus further includes a search unit that calculates the amount of quicksand per unit time from the database based on the input size mixing ratio of quicksand and the integral value of the acceleration per unit time.

Further, it is desirable to include an input section for inputting the diameter of the quicksand and the ratio of the size of the quicksand.
In addition, the quicksand amount measuring device of the present invention includes an accelerometer that outputs a detection signal representing the magnitude of impact with quicksand flowing in a river, and an integral value of acceleration per unit time and unit for each different size of quicksand. A database that has a plurality of combinations associated with the amount of quicksand per hour, and an envelope that connects the waveform by converting the waveform of the detection signal into an absolute value, and the envelope and a predetermined time frame. a first calculation unit that calculates a time integral value of the enclosed area; a second calculation unit that calculates an integral value of acceleration per unit time based on the time integral value; The apparatus includes a search section that calculates the amount of quicksand per unit time from the database based on the integral value of acceleration per unit time.

Moreover, it is preferable to include an input section for inputting the size of the quicksand.
The accelerometer may also include an acceleration sensor fixed within a sealed tube.

Further, in the present invention, the quicksand amount measuring device further includes a determination section that compares and determines the amount of quicksand per unit time and a water intake restriction threshold, and controls a gate drive section according to the determination result of the determination section. The determination unit closes the water intake gate when the amount of quicksand per unit time exceeds a water intake limit threshold. A water intake restriction signal is output to the gate driving section.

Further, in the present invention, the quicksand amount measuring device further includes a determination section that compares and determines the amount of quicksand per unit time and a water intake permissible threshold, and a gate drive section that determines the amount of quicksand according to the determination result of the determination section. is configured as a water intake control device for a hydroelectric power plant that controls and drives the water intake gate to open and close, and the determination unit is configured to control the water intake gate when the amount of quicksand per unit time is less than the water intake permissible threshold. A water intake permission signal for opening the gate is output to the gate driving section.

Further, in the present invention, the above-mentioned quicksand amount measuring device further includes a determination section that compares and determines the amount of quicksand per unit time, a water intake restriction threshold value, and a water intake permissible threshold value, and according to the determination result of the determination section. The system is configured as a water intake control device for a hydroelectric power plant that controls a gate drive unit to open and close a water intake gate, and the determination unit determines that if the amount of quicksand per unit time exceeds a water intake restriction threshold, A water intake restriction signal that closes the water intake gate is output to the gate drive unit, and when the amount of quicksand per unit time becomes less than the water intake permissible threshold, a water intake permission signal that opens the water intake gate is output to the gate drive unit. This is what is output.

According to the present invention, there is versatility and the amount of quicksand can be detected in any river.

FIG. 3 is an electrical block diagram of the quicksand amount measuring device according to the first embodiment. A schematic explanatory diagram of a test device. A waveform diagram of the output value of quicksand measured with a microphone. A waveform diagram of the output value of quicksand measured with an accelerometer. (a) is a graph showing the time change of the amount of quicksand, and (b) is a graph of the output waveform of the accelerometer with respect to the amount of quicksand. (a) is an explanatory diagram of the amount of quicksand in FIG. 4, and (b) is an explanatory diagram of the integral value of acceleration corresponding to the amount of quicksand in FIG. 4. (a) is a waveform diagram of the output signal of the accelerometer when it is hit by a glass bead with a diameter of 4 mm, and (b) is a waveform diagram of the output signal of the accelerometer when it is hit by a glass bead with a diameter of 2 mm. (a) is a waveform diagram of the output signal of the accelerometer when it is hit by a glass bead with a diameter of 1 mm, and (b) is a waveform diagram of the output signal of the accelerometer when it is hit by a glass bead with a diameter of 0.6 mm. (a) is a waveform diagram of the output signal of the accelerometer when silica sand No. 1 hits, and (b) is a waveform diagram of the output signal of the accelerometer when silica sand No. 3 hits. A waveform diagram of the output signal of the accelerometer when silica sand No. 5 hits. The characteristic diagram which shows the relationship between the integrated value of the output value of the accelerometer per unit time and the amount of quicksand per unit time when single grain sizes are separately introduced. The characteristic diagram which shows the relationship between the integrated value of the output value of the accelerometer per unit time and the amount of quicksand per unit time when silica sand with different particle sizes is mixed. An explanatory diagram of a database. The flowchart of the measurement program executed by the quicksand amount calculation device. FIG. 2 is an electrical block diagram of a quicksand amount measuring device and a water intake control device according to a second embodiment. FIG. 7 is a schematic explanatory diagram showing a state in which the water intake gate is opened in the water intake control device for a hydroelectric power plant according to the second embodiment. FIG. 7 is a schematic explanatory diagram of the water intake control device for a hydroelectric power plant according to the second embodiment, with the water intake gate closed. 2 is a flowchart of a determination program executed by the water intake control device. An explanatory diagram of river flow rate and amount of water used for power generation at a run-of-river hydroelectric power plant.

Hereinafter, a quicksand amount measuring device 10 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 13.
The quicksand amount measuring device 10 includes an accelerometer 20 and a quicksand amount calculation device 30. In the accelerometer 20, an acceleration sensor 22 is housed in a storage case 24. The material and structure of the storage case 24 are not limited, but since the storage case 24 is placed in a river, it is preferable that it has a watertight structure and will not be damaged even if it is hit by quicksand. For example, the material of the storage case 24 is preferably metal, synthetic resin, or the like. In the present embodiment, the storage case 24 is made of a circular tube or the like, and both ends are closed in a watertight manner by a lid 26. The acceleration sensor 22 is integrally fixed to the inner surface of the storage case 24 so that an impact when quicksand hits the storage case 24 can be transmitted to the acceleration sensor 22. The output signal of the acceleration sensor 22 is electrically connected to a quicksand amount calculation device 30 via a signal line 28.

The quicksand amount calculating device 30 is composed of a computer having a CPU (central processing unit) 31, a RAM, a ROM (both not shown), a storage device 32, etc., and stores a measurement program stored in the ROM or storage device 32 in advance in the RAM. By loading and executing the program, the functions of each part described later are realized. That is, the quicksand amount calculation device 30 realizes the functions of the first calculation section 33, the second calculation section 34, and the search section 35 based on the measurement program. Further, the storage device 32 stores a database.

An input section 37 is connected to the quicksand amount calculation device 30 . The input unit 37 includes a keyboard, a mouse, and the like. The input unit 37 allows the mixing ratio to be input to the quicksand amount calculating device 30 each time the size of quicksand differs.

<About the database>
Describe the database. The database contains the integral value of the output signal of the accelerometer 20 per unit time (that is, the integral value of the acceleration per unit time) and the accelerometer per unit time for each mixing ratio of quicksand with different particle sizes. 20 is associated with the amount of quicksand that has passed through. Based on the mixing ratio of quicksand with different particle sizes and the integral value of acceleration per unit time, it is possible to search for the amount of quicksand passing through the accelerometer 20 per unit time corresponding to the integral value of acceleration. There is. The database will be described in further detail with reference to FIG. 13.

<About the test>
It will be explained that there is a unique relationship between these two integral values.
FIG. 2 shows the test equipment. The test device is used to obtain the relationship between the time change in the amount of quicksand and the time change in the output signal of the accelerometer 20.

As shown in FIG. 2, the test device is integrally connected to a hopper 110 for storing sand S, a storage tank 112 for storing sand S input from the hopper 110 and supplied water W, and a lower part of the storage tank 112. It also includes a flow pipe 114 in which the accelerometer 20 is arranged in a direction perpendicular to the flow of water W, and a sand collection tank 116 integrally connected to the lower part of the flow pipe 114. From the storage water tank 112, water W and sand S flow through the flow pipe 114 under their own weight. When the accelerometer 20 is hit by the sand S (that is, quicksand) flowing through the channel pipe 114, it outputs a detection signal that detects the impact at the time of the hit to the quicksand amount calculation device 30 shown in FIG. There is. Note that for convenience of explanation, the detection signal may be referred to as an output signal.

Water W stored in the sand recovery tank 116 is made to flow into an underground water tank 118 provided below the sand recovery tank 116. Further, the water W in the underground water tank 118 is pumped to the elevated water tank 122 by the submersible pump 120, and then returns to the storage water tank 112 via the water supply pipe 126 equipped with a flow rate control valve 124. The water level of the elevated water tank 122 is controlled by driving the submersible pump 120 so that it is always higher than the water level of the storage water tank 112.

FIG. 3 shows the output signal of the microphone in the case where a microphone (not shown) as a comparative example (underwater microphone) was placed in the flow path pipe 114 of the same test device and tested. Specifically, FIG. 3 shows the output signal of the microphone when the quicksand hits the microphone when sand S having a diameter of 4 mm and 1 kg and running water of 40 L/s are introduced.

The microphone was placed so as to be covered with a tube material of the same size as the storage case 24 of the accelerometer 20. As shown in FIG. 3, the amplitude of the output signal is larger in the time period T1 when quicksand is not hitting and the time period T2 when quicksand is hitting.

On the other hand, FIG. 4 shows that when the accelerometer 20 is placed in the flow pipe 114 and sand S with a diameter of 2 mm and 1 kg and running water of 40 L/s are introduced, as shown in FIG. It represents the output signal of the accelerometer 20 when the object hits the object.

As shown in FIG. 4, the amplitude of the output signal is larger in the time period T2 when quicksand is present, but the amplitude of the output signal is larger in the time period T2 when quicksand is present. What is important is that the amplitude of the signal from the accelerometer 20 when it is not hit by quicksand is extremely small compared to the microphone shown in FIG. Then, in the time period T2 during which quicksand hits, at the end of the period, when the frequency of quicksand hits decreases, it becomes possible to clearly grasp the convergence status of the amplitude. On the other hand, in the case of the microphone shown in Fig. 3, in the time period T2 when quicksand hits, at the end of the period, when the frequency of quicksand hits decreases, the amplitude decreases and noise interferes with the detection of the quicksand. has become difficult. In FIG. 4, the arrows indicate the convergence of the amplitude of the output signal after the corresponding time period.

<Relationship between the amount of quicksand and the output signal of the accelerometer>
FIG. 5(a) shows the change over time in the amount of quicksand that passed through the detection location where the accelerometer 20 was placed in the testing device. Moreover, FIG. 5(b) shows a graph of the output waveform of the accelerometer with respect to the amount of quicksand when measured in FIG. 5(a).

In FIG. 6(a), in the same output signal of the accelerometer 20 as in FIG. 5(a), the area of the hatched area during the period of Δt is the amount (g) of quicksand that has passed during this period. If the amount of quicksand that has passed (g) is divided by Δt, the amount of quicksand per unit time (mg/s) is obtained.

On the other hand, in FIG. 6(b), when the output signal of FIG. 5(b) is A, it is set to |A|, that is, the waveform is inverted from a negative value of 0 or less to a positive value, and the waveform The peak values of are connected by an envelope H.

During the period of Δt, the area of the hatched region whose upper limit is the envelope H becomes the time integral value of the acceleration during this period. Dividing this time integral value of acceleration by Δt gives the integral value of acceleration per unit time.

A database is obtained by associating the amount of quicksand per unit time (mg/s) with the integral value of acceleration per unit time.
<About test data>
An example of test data will be explained.

Examples of the output signal of the accelerometer 20 when glass beads with different diameters and silica sand with different sizes are flowed together with water W as quicksand using the test apparatus are shown in FIGS. 7(a) and 7(a). b), FIG. 8(a), FIG. 8(b), FIG. 9(a), FIG. 9(b), and FIG.

FIG. 7A is a waveform diagram of the output signal of the accelerometer 20 when the glass beads with a diameter of 4 mm and 2 kg hit the accelerometer 20 when water was passed through the glass beads at a flow rate of 60 L/s. FIG. 7(b) is a waveform diagram of the output signal of the accelerometer 20 when the glass beads with a diameter of 2 mm and 2 kg hit the accelerometer 20 when water was passed through the glass beads at a flow rate of 60 L/s. FIG. 8(a) is a waveform diagram of the output signal of the accelerometer 20 when the glass beads hit the accelerometer 20 when water was passed through glass beads having a diameter of 1 mm and weighing 2 kg at a flow rate of 60 L/s. FIG. 8(b) is a waveform diagram of the output signal of the accelerometer 20 when the glass beads hit the accelerometer 20 when water is passed through glass beads having a diameter of 0.6 mm and weighing 2 kg at a flow rate of 60 L/s. be.

Figure 9(a) shows when glass beads hit the accelerometer 20 when 2 kg of silica sand No. 1, which mainly has particles of about 4.3 mm in size, was passed through water at a flow rate of 40 L/s. FIG. 2 is a waveform diagram of an output signal of the accelerometer 20 of FIG. Figure 9(b) shows when the glass beads hit the accelerometer 20 when water was passed through 2 kg of No. 3 silica sand, which mainly contains particles with a size of about 1.6 mm, at a flow rate of 40 L/s. FIG. 2 is a waveform diagram of an output signal of the accelerometer 20 of FIG.

Figure 10 shows the accelerometer when the glass beads hit the accelerometer 20 when 2 kg of silica sand No. 5, which mainly has particles of about 0.5 mm in size, was passed through water at a flow rate of 40 L/s. 20 is a waveform diagram of the output signal of No. 20. FIG.

Furthermore, after changing the water flow rate multiple times for the glass beads with different diameters and the silica sand of each of the above items, the accelerometer when the glass beads with different diameters and the silica sand of each of the above items hit the accelerometer 20. Obtain the output signal (output value) of

The output signal (output value) A related to the glass beads with different diameters and the silica sand of the above items obtained as described above is set to |A|, the peak value of the waveform is connected by the envelope H, and the acceleration is detected. The time integral value of the acceleration of the area surrounded by the envelope during the time from the start of detection to the end of detection is calculated. Then, this time integral value of acceleration is divided by the time from the start of detection to the end of detection to obtain the integral value of acceleration per unit time.

On the other hand, together with each measurement by the accelerometer 20, the amount of quicksand of the glass beads and silica sand is measured. The method for measuring the amount of quicksand is, for example, based on the amount of glass beads and silica sand thrown in during the period from the detection start time when glass beads and silica sand hit to the detection end time when detection became impossible. The method is not limited.

By dividing the amount of quicksand that passed during this period by the period from the detection start time to the detection end time when detection became impossible, the amount of quicksand per unit time (mg/s) is obtained.
In FIG. 11, the data obtained in the above test is plotted with the vertical axis representing the integral value of acceleration per unit time obtained as described above and the horizontal axis representing the amount of quicksand per unit time.

As shown in Figure 11, the groups in which the test data for 4mm glass beads and No. 1 silica sand (size 4.3mm) are plotted can be combined into one group, and in Figure 11, the "4mm group" It is said that Further, the group in which the test data of 2 mm glass beads and No. 3 silica sand (size 1.6 mm) are plotted can be combined into one group, and in FIG. 11, it is referred to as the "2 mm group". Furthermore, a group in which test data of 1 mm glass beads are plotted can be grouped together as a "1 mm group." In addition, the groups in which the test data of glass beads 0.6 mm and silica sand No. 5 (size 0.5 mm) are plotted can be combined into one group, and in Figure 11, it is called "0.6 mm group". .

As shown in Figure 11, in these groups, the larger the integral value of acceleration per unit time, the larger the amount of quicksand per unit time, and the regression curve (quicksand amount curve) for each size such as the diameter of quicksand. It is now possible to model.

In addition, silica sand No. 1 and No. 3 alone or silica sand No. 1, No. 3, and No. 5 were mixed at different mixing ratios, data was obtained using the test device, and based on these data, the same procedure as above was performed. The integral value of acceleration per unit time and the amount of quicksand per unit time were calculated. In FIG. 12, each data is plotted with the vertical axis representing the obtained integral value of acceleration per unit time and the horizontal axis representing the amount of quicksand per unit time.

The tests plotted in Figure 12 are "silica sand No. 1 only", "silica sand No. 3 only", "silica sand No. 1 and No. 3 mixed at a ratio of 3:1", and "silica sand No. 1 and No. 3 mixed at a ratio of 1:1". ” and “Mix silica sand No. 1 and No. 3 at a ratio of 1:3.” In addition, the tests plotted in Figure 12 are "Mixing silica sand No. 1, No. 3, and No. 5 at a ratio of 1:1:1", "Mixing silica sand No. 1, No. 3, and No. 5 at a ratio of 1:1:3", Includes "Mixing silica sand No. 3 and No. 5 at a ratio of 1:1" and "Mixing silica sand No. 3 and No. 5 at a ratio of 1:3."

In the test results plotted in FIG. 12, groups Ga and Gb can be distinguished.
Group Ga includes "silica sand No. 1 only,""silica sand No. 1 and No. 3 mixed at a ratio of 3:1,""silica sand No. 1 and No. 3 mixed at a ratio of 1:1," and "silica sand No. 1 and No. 3 mixed at a ratio of 1:1." Silica sand No. 1 of "Mixing silica sand No. 1, No. 3, and No. 5 at a ratio of 1:1:1" and "Mixing silica sand No. 1, No. 3, and No. 5 at a ratio of 1:1:3" This is a group that includes

Group Gb includes "silica sand No. 3 only", "silica sand No. 3 and No. 5 mixed at a ratio of 1:1", and "silica sand No. 3 and No. 5 mixed at a ratio of 1:3" with silica sand No. 1 not mixed. This groove contains silica sand No. 3.

As shown in FIG. 12, in each of groups Ga and Gb, the larger the integral value of acceleration per unit time, the larger the amount of quicksand per unit time. It is now possible to model the quantity curve).

Moreover, when silica sands of different sizes are mixed in this way, it can be seen that the amount of quicksand per unit time is influenced by the silica sand that is the largest among the mixed ones.
Based on the above test results, in the database of this embodiment, quicksand is leveled into multiple levels in order of size. Although the width of the level is not limited, for example, the level may be divided into arbitrary numerical values between 1 and 10 mm. The size of quicksand is, for example, a particle size, but may also be a value such as a mesh value, which is a value that measures the size of powder or granules.

For example, when the width of the level is divided into four levels every 1 mm, a1<a2<a3<a4. When a1≦1mm, 1mm<a2≦2mm, 2mm<a3≦3mm, and 3mm≦a4.

In the example shown in FIG. 13, the proportions at levels a1 to a4 are expressed as b1, b2, b3, and b4 (%), respectively, and the proportions are set in units of 10%.
In the same figure, the table shows the integral value of acceleration per unit time (vertical axis) and the amount of quicksand per unit time (horizontal axis) when b4 is 70%, b3 is 20%, b2 is 10%, and b1 is 0%. It is shown. In this way, the database has a plurality of combinations in which the integral value of acceleration per unit time and the amount of quicksand per unit time are associated with each other for different mixing ratios of quicksand sizes.

(Action of embodiment)
Next, the operation of the quicksand amount measuring device 10 in which the accelerometer 20 is placed in a river such as a riverbed will be explained. FIG. 14 is a flowchart executed by the CPU 31 of the quicksand amount calculation device 30 according to the measurement program.

In S20, the CPU 31 (first calculation unit 33) converts the output signal A input at predetermined time intervals from the accelerometer 20 into |A|, and calculates an envelope connecting the peak values of the waveform. . Note that the method for calculating the envelope is not limited, and any well-known technique may be used. For example, the envelope may be calculated using root mean square (RMS), Hilbert envelope, or the like. In this embodiment, a peak envelope is calculated.

Subsequently, the CPU 31 (first calculation unit 33) calculates the time integral value of the acceleration in the area surrounded by the calculated envelope and the predetermined time frame (see FIG. 6(b)).
In S30, the CPU 31 (second calculation unit 34) calculates an integral value of acceleration per unit time by dividing the time integral value of the acceleration by the predetermined time frame.

In S40, the CPU 31 (search unit 35) calculates the amount of quicksand per unit time from the database based on the mixing ratio of the size of river quicksand input from the input unit 37 and the integral value of the acceleration per unit time. The amount of quicksand that is the search result is output to a display (not shown), a printer, etc. as the amount of quicksand that is output based on the detection signal.

Note that the mixing ratio of the size of the river quicksand input from the input unit 37 is determined in the same time frame as the time when the accelerometer 20 is detecting river water placed near the accelerometer 20 placed in the river. The water was taken in, and the mixing ratio was measured based on the obtained quicksand using a known distribution meter that measures the particle size and distribution of bed bed or quicksand. In the input unit 37, for example, in the case of the levels a1 to a4, the ratios are input as b1, b2, b3, and b4, respectively.

This embodiment has the following features.
(1) The quicksand amount measuring device 10 of this embodiment includes an accelerometer 20 that outputs a detection signal representing the magnitude of impact with quicksand flowing in a river. Further, the quicksand amount measuring device 10 has a database having a plurality of combinations in which the integral value of acceleration per unit time and the amount of quicksand per unit time are associated for each time the mixing ratio of the size of quicksand is different. have.

The quicksand amount measuring device 10 also includes a first calculation unit 33 that calculates a time integral value of an area surrounded by an envelope connecting the waveform obtained by converting the detection signal into an absolute value and a predetermined time frame; A second calculation unit 34 is provided which calculates an integral value of acceleration per unit time based on the second calculation unit 34 . Further, the quicksand amount measuring device 10 includes a search unit 35 that calculates the amount of quicksand per unit time from the database based on the input size mixing ratio of quicksand and the integral value of acceleration per unit time.

As a result, it is versatile and can detect the amount of quicksand in any river.
(2) The quicksand amount measuring device 10 of this embodiment includes an input section 37 for inputting the size of quicksand and the mixing ratio of quicksand sizes. With the above configuration, it is possible to obtain the amount of quicksand per unit time from the database.

(3) Furthermore, in this embodiment, the accelerometer 20 includes an acceleration sensor 22 fixed within a sealed tube. As a result, the acceleration sensor 22 can be placed in water such as a river without any problem.

(Second embodiment)
Next, the water intake control device 200 for the run-of-river hydroelectric power plant 240 will be described with reference to FIGS. 15 to 18.

As shown in FIG. 15, the water intake control device 200 includes a determination device 40 to which accelerometers 20A and 20B are connected. The determination device 40 including the accelerometers 20A and 20B corresponds to a quicksand amount measuring device. The determination device 40 controls a gate drive unit 50 that drives the water intake gate 60 to open and close.

The determination device 40 is composed of a computer having a CPU (central processing unit) 41, a RAM, a ROM (both not shown), a storage device 42, etc., and reads a determination program stored in the ROM or storage device 42 in advance into the RAM. By executing this, the functions of each part described later are realized. That is, the determination device 40 realizes the functions of the first calculation section 43, the second calculation section 44, the search section 45, and the determination section 46 based on the determination program.

Further, the storage device 42 stores a database. The first calculation unit 43, the second calculation unit 44, the search unit 45, and the database are configured or function similarly to the first calculation unit 33, the second calculation unit 34, the search unit 35, and the database in the first embodiment. do. Further, the determination device 40 is provided with an interface 47 as an input section.

Accelerometers 20A and 20B are configured similarly to accelerometer 20 of the first embodiment.
In the run-of-river hydroelectric power plant 240, water from the river 205 flows into the settling basin 210 through the water intake 206 when the water intake gate 60 is opened, as shown in FIG. Although not shown, since the sand settling basin 210 is wider than the water intake port 206, the flow velocity decreases, and the sand flowing with the water settles to the bottom. Water is then sent from headrace 212 to water tank 220 . The water tank 220 is used to temporarily store water prior to power generation, and the remaining sand settles here as the flow rate decreases. The water stored in the water tank 220 falls through a penstock 230 installed on a slope, turns a water wheel (not shown) of a run-of-river hydroelectric power plant 240, and is returned to the river from a spillway (not shown). Further, the water turbine drives a generator (not shown) to generate electric power.

As shown in FIG. 16, the accelerometer 20A is placed closer to the river than the intake gate 60 of the water intake 206 in order to detect the amount of quicksand flowing near the water intake 206 in the river 205. The accelerometer 20B is arranged closer to the settling basin 210 than the water intake gate 60 in the water intake 206 in order to detect the amount of quicksand flowing from the water intake gate 60.

As shown in FIG. 15, quicksand distribution measuring devices 70A and 70B are electrically connected to the determination device 40 via an interface 47, respectively. As shown in FIG. 16, detectors 80A and 80B are electrically connected to the quicksand distribution measuring devices 70A and 70B. The interface 47 corresponds to an input section.

The detectors 80A and 80B are, for example, waterproof piezoelectric sensors, and are electrically connected to quicksand distribution measuring devices 70A and 70B, respectively, which analyze acoustic information when quicksand hits. Detectors 80A and 80B are placed near accelerometers 20A and 20B, respectively. The quicksand distribution measuring devices 70A and 70B analyze this acoustic information, that is, only signals in a specific frequency band corresponding to the flow of dirt particles are passed through the filter. The quicksand distribution measuring devices 70A and 70B are equipped with a multi-channel counter unit that counts the number of specific acoustic information that has passed for each signal strength, so that the quicksand distribution measurement devices 70A and 70B can measure the particle size distribution of quicksand, that is, the quicksand distribution. It is now possible to measure the size mixing ratio (ie, particle size distribution). Note that this method is known, for example, in Japanese Utility Model Application Publication No. 05-52972, so detailed explanation will be omitted. Note that the device for measuring the particle size distribution is not limited to this method, and other known devices may be used.

In addition, in the configuration of the water intake control device 200 of this embodiment, the accelerometers 20A and 20B, the storage device 42 of the determination device 40, the first calculation section 43, the second calculation section 44, the search section 45, and the interface 47 are configured to measure the amount of quicksand. Configure the instrument.

(Action of the second embodiment)
Next, the operation of the water intake control device 200 will be explained with reference to the flowchart of FIG. 18.
The flowchart in FIG. 18 is executed by the CPU 41 of the determination device 40 at predetermined intervals according to the determination program.

(S110)
In S110, the CPU 41 sets a flag indicating the water intake gate state. That is, an open position limit switch (not shown) outputs an on signal to the determination device 40 when the water intake gate 60 is in the open position, and an on signal is output to the determination device 40 when the water intake gate 60 is in the closed position. A closed position limit switch (not shown) is provided.

The CPU 41 of the determination device 40 sets the state identification flag F to "1" when the ON signal from the open position limit switch is input, and sets the state identification flag F to "0" when the ON signal from the closed position limit switch is input. ”.

(S120-S140)
The following processing from S120 to S140 is performed separately depending on whether the status identification flag F is "0" or "1" because the data acquisition source for calculating the amount of quicksand per unit time R is different. I will explain.

<1. When the status identification flag F is “0”>
In S120, the CPU 41 (first calculation unit 43) converts the output signal A input at predetermined time intervals from the accelerometer 20A into |A|, and calculates an envelope connecting the peak values of the waveform. . Note that the method for calculating the envelope is the same as in the first embodiment. Subsequently, the CPU 41 (first calculation unit 43) calculates the time integral value of the acceleration in the area surrounded by the calculated envelope and the predetermined time frame.

In S130, the CPU 41 (second calculation unit 44) calculates the integral value of acceleration per unit time by dividing the time integral value of the acceleration by the predetermined time frame.
In S140, the CPU 41 (search unit 45) searches the database based on the mixing ratio of the size of quicksand in the river 205 inputted from the quicksand distribution measuring device 70A via the interface 47 and the integrated value of the acceleration per unit time. From this, the amount R of quicksand per unit time is searched and obtained. The mixing ratio of the size of quicksand in the river 205 inputted from the quicksand distribution measuring device 70A is obtained at the same time as the output signal A for each predetermined time inputted from the accelerometer 20A at predetermined time intervals.

Here, the reason why the mixing ratio of the size of quicksand in the river 205 is obtained from the quicksand distribution measuring device 70A is that the current flow rate R of quicksand per unit time in the river 205 is applied to the equipment of the run-of-the-river type hydroelectric power plant 240. This is to find out whether the particles have a particle size that will not cause damage. In other words, the current distribution (particle size distribution) and amount of quicksand in the river 205 can be accurately grasped, and quicksand that may adversely affect the equipment of the run-of-river hydroelectric power plant 240, such as wear of the turbine runner or penstock 230, can be determined. This is to know the distribution (particle size distribution) and amount of quicksand, and to judge whether it is okay to restart power generation.

<2. When the status identification flag F is “1”>
In S120, the CPU 41 (first calculation unit 43) converts the output signal A input at predetermined time intervals from the accelerometer 20B into |A|, and calculates an envelope connecting the peak values of the waveform. . Note that the method for calculating the envelope is the same as in the first embodiment. Subsequently, the CPU 41 (first calculation unit 43) calculates the time integral value of the acceleration in the area surrounded by the calculated envelope and the predetermined time frame.

In S130, the CPU 41 (second calculation unit 44) calculates the integral value of acceleration per unit time by dividing the time integral value of the acceleration by the predetermined time frame.
In S140, the CPU 41 (search unit 45) calculates the mixing ratio of the size of quicksand downstream of the water intake 206 from the water intake gate 60 input from the quicksand distribution measuring device 70B via the interface 47, and the acceleration per unit time. Based on the integral value of , the amount of quicksand per unit time R is searched and obtained from the database. The mixing ratio of the size of quicksand passing through the water intake 206 input from the quicksand distribution measuring device 70B is obtained at the same time as the output signal A for each predetermined time input from the accelerometer 20B. It is.

Here, the reason why the mixing ratio of the size of quicksand downstream of the water intake 206 from the water intake gate 60 is acquired from the quicksand distribution measuring device 70B is as follows. In other words, the distribution (particle size distribution) and amount of quicksand passing through the water intake 206 rather than the water intake gate 60 can be accurately grasped, and the equipment of the run-of-river type hydroelectric power plant 240 can be checked to prevent wear and tear on the water turbine runners and penstock 230, etc. This is to know whether the quicksand distribution (particle size distribution) and the amount of quicksand are causing an adverse effect, and to judge whether or not power generation should be stopped.

(S150)
In S150, the CPU 41 determines whether the state identification flag F is "0" or not. Then, the CPU 41 moves to S160 when the state identification flag F is "0", and moves to S190 when the state identification flag F is "1".

(S160)
In S160, the CPU 41 (determination unit 46) determines whether the amount of quicksand per unit time R is less than the water intake permissible threshold RO. If the amount of quicksand per unit time R is less than the allowable water intake threshold RO, the CPU 41 moves to S170, and if the amount of quicksand per unit time R is equal to or greater than the allowable water intake threshold RO, returns to S110. The water intake gate 60 is kept closed.

(S170)
In S170, the CPU 41 (determination unit 46) outputs a water intake permission signal for opening the water intake gate 60 to the gate drive unit 50. The gate drive unit 50 opens the water intake gate 60 in response to the water intake permission signal.

(S180)
In S180, the CPU 41 sets the state identification flag F to "1" and returns to S110.

(S190)
In S190, the CPU 41 (determination unit 46) determines whether the amount of quicksand per unit time R exceeds the water intake restriction threshold RC. In this embodiment, water intake permissible threshold RO<water intake restriction threshold RC. If the amount of quicksand per unit time R exceeds the water intake limit threshold RC, the CPU 41 moves to S200, and if the amount of quicksand per unit time R is less than or equal to the water intake limit threshold RC, returns to S110. In this way, the water intake gate 60 is kept open.

In the present embodiment, the magnitude relationship between the water intake permissible threshold RO and the water intake restriction threshold RC is not limited to water intake permissible threshold RO<water intake restriction threshold RC, and may be the same value, or water intake permissible threshold RO>water intake. It may also be a limit threshold RC.

(S200)
If the amount of quicksand per unit time R exceeds the water intake restriction threshold RC, the CPU 41 (judgment unit 46) outputs a water intake restriction signal for closing the water intake gate 60 to the gate drive unit 50. The gate drive unit 50 closes the water intake gate 60 in response to the water intake restriction signal.

(S210)
In S210, the CPU 41 resets the state identification flag F to "0" and returns to S110.

This embodiment has the following features.
(1) The water intake control device 200 for a hydroelectric power plant according to the present embodiment includes a sediment flow meter that can detect the flow sand amount in any river. Then, when the amount of quicksand per unit time R exceeds the water intake restriction threshold RC, the determination unit 46 of the water intake control device 200 outputs a water intake restriction signal that closes the water intake gate 60 to the gate drive unit 50. Further, when the amount of quicksand per unit time R becomes less than the water intake permissible threshold RO, the determination unit 46 outputs a water intake permissible signal for opening the water intake gate 60 to the gate drive unit 50 .

As a result, this embodiment has versatility and can detect the amount of quicksand in any river, and can open and close the water intake gate of a run-of-river hydroelectric power plant.
FIG. 19 shows an example of a change in river flow rate when it rains in the upstream area of a river where the run-of-river hydroelectric power plant 240 is located.

In FIG. 19, the maximum water intake amount R10 is the maximum flow rate allowed when the run-of-river hydroelectric power plant 240 generates power.
Empirical judgment The flow rate R11 is the amount at which the monitor empirically predicts that when the amount of water in the river is increasing, the amount of quicksand (sediment) flowing with the river water will also increase, and it is difficult to draw more water than this amount. Then, the water intake gate 60 is closed because the equipment of the hydroelectric power plant will be damaged. Since the empirically determined flow rate R11 includes errors, a safety margin is expected.

Empirically determined flow rate R12 is the amount at which a monitor empirically predicts that when the amount of water in a river is decreasing, the amount of quicksand (sediment) flowing with the river water will also decrease. The water intake gate 60 is opened as long as the equipment is not damaged. Since the empirically determined flow rate R12 includes errors, a safety margin is expected.

As a result, conventionally, based on the empirical judgment flow rate R11, the area of the river water amount below the maximum water intake amount R10 until the time t1 when the water intake gate 60 is closed, and the intake gate based on the empirical judgment flow rate R12. The amount of river water less than or equal to the maximum water intake amount R10 from time t2 when 60 is opened becomes the amount of water used for power generation. The amount predicted empirically by the above-mentioned monitor is not constant, but a fluctuating value, because errors are expected as mentioned above, and it is also affected by the state of the water flowing into the river. be.

On the other hand, the determined river flow rate R21 is a river flow rate calculated based on the water intake restriction threshold RC, and when the amount of quicksand per unit time R exceeds the water intake restriction threshold RC, the water intake gate 60 is closed. This is the river flow rate when

In other words, the amount of quicksand per unit time R is often related to the river flow rate, and as the river flow rate increases, the amount of quicksand per unit time also tends to increase. A safety margin is expected when estimating . On the other hand, in this embodiment, water intake time, which conventionally was stopped at t1, can be extended to t11. FIG. 19 illustrates such a case.

Therefore, as shown in FIG. 19, the determined river flow rate R21 has a larger value than the empirical determined flow rate R11.
In addition, the determined river flow rate R22 is a river flow rate calculated based on the water intake permissible threshold RO, and when the water intake gate 60 is opened when the amount of quicksand per unit time R becomes less than the water intake permissible threshold RO. This is the river flow rate.

In other words, the amount of quicksand per unit time R is often related to the river flow rate, and as the river flow rate decreases, the amount of quicksand per unit time also tends to decrease. A safety margin is assumed in the estimation of , and it becomes possible to extend the water intake time to t21, which previously started at t2. FIG. 19 illustrates such a case.

Additionally, unlike the conventional method of estimating the amount of sand sand empirically from river flow rates, it is possible to directly determine the amount of sand sand using a sand flow meter, allowing for more appropriate equipment operation and maintenance.
The determined river flow rate R22 can be obtained through a test or the like, and is a value that can be uniquely obtained from the water intake permissible threshold RO. As shown in FIG. 19, the determined river flow rate R22 that can be obtained based on the water intake permissible threshold RO can reduce the error as compared to the empirical determined river flow rate R12.

Therefore, as shown in FIG. 19, the determined river flow rate R22 has a larger value than the empirical determined flow rate R12.
As a result, in this embodiment, the intake gate 60 is determined based on the region of the river water volume less than or equal to the maximum water intake amount R10 until the time t11 when the water intake gate 60 is closed based on the determined river flow rate R21, and on the basis of the determined river flow rate R22. The area of the river water amount below the maximum water intake amount R10 from the opening time t21 becomes the amount of water used for power generation.

Therefore, as shown in FIG. 19, compared to the conventional method, the amount of power generation used can be increased by the area shown by hatching. That is, by improving the accuracy of stopping and restarting power generation, it is possible to reduce power generation loss and increase the amount of power generation. In addition, since the amount of quicksand can be directly determined using a quicksand amount measuring device, more appropriate equipment operation and maintenance is possible.

This embodiment can be implemented with the following modifications.
This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

- The quicksand amount measuring device 10 of the first embodiment includes an input section 37 for inputting the size of quicksand and the mixing ratio of quicksand sizes. Alternatively, if only quicksand of the same size flows into a river or the like, an input section for inputting the size of the quicksand may be used instead. In this case, the database only needs to have a plurality of combinations in which the integral value of acceleration per unit time and the amount of quicksand per unit time are associated with each other for each different size of quicksand.

- In the second embodiment, the accelerometers 20A and 20B are provided, but one of them is omitted, and the determination device 40 controls the opening and closing of the gate drive unit 50 based on the detection signal of the remaining accelerometer. You may. In this case, either one of the quicksand distribution measuring devices 70A, 70B and the detectors 80A, 80B may be omitted.

In this case, if the accelerometer 20A, the quicksand distribution measuring device 70A, and the detector 80A are omitted, the accelerometer 20B can determine whether to stop water intake, but cannot determine whether to resume water intake (opening the intake gate). The operator can determine this and restart the water intake.

Furthermore, if the accelerometer 20B, the quicksand distribution measuring device 70B, and the detector 80B are omitted, for example, the accelerometer 20A and the quicksand distribution measuring device 70A can be used instead of the accelerometer 20B, the quicksand distribution measuring device 70B, and the detector 80B. The gate drive unit 50 may be controlled to close based on the output signal. Alternatively, the operator may determine this and control the gate drive unit 50 to close.

- In the second embodiment, the quicksand distribution measuring devices 70A and 70B are electrically connected to the outside of the determining device 40 shown in FIG. 15, but the determining device 40 has the functions of the quicksand distribution measuring devices 70A and 70B. You can leave it there. In this case, detectors 80A and 80B are electrically connected to interface 47. The interface 47 corresponds to an input section.

- Also, in the second embodiment, the single determination device 40 performs a comparative judgment between the amount of quicksand per unit time and the water intake limit threshold RC, and a comparative judgment between the amount of quicksand per unit time and the water intake permissible threshold RO.

Instead, a determination device to which the accelerometer 20A and the quicksand distribution measuring device 70A are electrically connected, and a determining device to which the accelerometer 20B and the quicksand distribution measuring device 70B are electrically connected may be provided, respectively. .

In this case, the determination unit 46 of the determination device to which the accelerometer 20A and the quicksand distribution measuring device 70A are electrically connected closes the water intake gate 60 when the amount of quicksand per unit time exceeds the water intake restriction threshold RC. It is assumed that a water intake restriction signal is output to the gate drive section 50.

Further, the determination unit 46 of the determination device to which the accelerometer 20B and the quicksand distribution measuring device 70B are electrically connected opens the water intake gate 60 when the amount of quicksand per unit time becomes less than the water intake permissible threshold RO. It is assumed that a water intake permission signal is output to the gate drive section 50.

- In the second embodiment, an input unit such as an input keyboard may be provided in place of the interface 47 as in the first embodiment. In this case, the user may input the mixing ratio of the sizes of quicksand output by the quicksand distribution measurement devices 70A and 70B by operating the input unit in the same manner as in the first embodiment.

- In the second embodiment, the quicksand distribution measuring devices 70A, 70B and the detectors 80A, 80B may be omitted. In this case, in S140 of FIG. 18, the CPU 41 (search unit 45) searches and obtains the amount of quicksand per unit time R from the database based on the integral value of acceleration per unit time.

- Also, in the second embodiment, one of the quicksand distribution measuring devices 70A, 70B, the detectors 80A, 80B, and the accelerometers 20A, 20B is omitted, and the detection signal of the other remaining accelerometer is used. Based on this, the determination device 40 may control the opening and closing of the gate drive unit 50.

In this case, if the accelerometer 20A, the quicksand distribution measuring device 70A, and the detector 80A are omitted, the accelerometer 20B can determine whether to stop water intake, but cannot determine whether to restart water intake (opening the intake gate). The operator can determine this and restart the water intake.

Further, if the accelerometer 20B, the quicksand distribution measuring device 70B, and the detector 80B are omitted, the gate drive unit 50 may be controlled to close based on the output signal of the accelerometer 20A. Alternatively, the operator may determine this and control the gate drive unit 50 to close.

10... Quicksand amount measuring device 20, 20A, 20B... Accelerometer,
22... Acceleration sensor 30... Quicksand amount calculation device 31... CPU
32...Storage device 33...First calculation unit 34...Second calculation unit 35...Search unit 37...Input unit 40...Determination device 41...CPU
42... Storage device 43... First calculation section 44... Second calculation section 45... Search section 46... Judgment section 47... Interface 50... Gate drive section 60... Water intake gate 70A, 70B... Quicksand distribution measuring device 80A, 80B... Detection Container 200... Water intake control device 205... River 206... Water intake 210... Sediment basin 212... Headrace 220... Water tank 230... Penstock 240... Run-of-river power plant

Claims (8)

An accelerometer that outputs a detection signal indicating the magnitude of impact with quicksand flowing in a river,
a database having a plurality of combinations in which the integral value of acceleration per unit time and the amount of quicksand per unit time are associated for each different mixing ratio of the size of quicksand;
a first calculation unit that converts the waveform of the detection signal into an absolute value, calculates an envelope connecting the waveform, and calculates a time integral value of an area surrounded by the envelope and a predetermined time frame;
a second calculation unit that calculates an integral value of acceleration per unit time based on the time integral value;
A quicksand amount measuring device having a search unit that calculates the amount of quicksand per unit time from the database based on the input size mixing ratio of quicksand and the integral value of the acceleration per unit time. The quicksand amount measuring device according to claim 1, further comprising an input section for inputting the size of the quicksand and the mixing ratio of the quicksand size. An accelerometer that outputs a detection signal indicating the magnitude of impact with quicksand flowing in a river,
a database having a plurality of combinations in which the integral value of acceleration per unit time and the amount of quicksand per unit time are associated for each different size of quicksand;
a first calculation unit that converts the waveform of the detection signal into an absolute value, calculates an envelope connecting the waveform, and calculates a time integral value of an area surrounded by the envelope and a predetermined time frame;
a second calculation unit that calculates an integral value of acceleration per unit time based on the time integral value;
A quicksand amount measuring device having a search unit that calculates the amount of quicksand per unit time from the database based on the inputted size of quicksand and the integrated value of the acceleration per unit time. The quicksand amount measuring device according to claim 1, further comprising an input section for inputting the size of the quicksand. The quicksand amount measuring device according to any one of claims 1 to 4, wherein the accelerometer includes an acceleration sensor fixed in a sealed pipe. The quicksand amount measuring device according to any one of claims 1 to 5 further includes a determination unit that compares and determines the amount of quicksand per unit time and a water intake restriction threshold, and the determination result of the determination unit It is configured as a water intake control device for a hydroelectric power plant that controls the gate drive unit to open and close the water intake gate according to the
A water intake control device for a hydroelectric power plant, wherein the determination unit outputs a water intake restriction signal for closing a water intake gate to the gate drive unit if the amount of quicksand per unit time exceeds a water intake restriction threshold. The quicksand amount measuring device according to any one of claims 1 to 5 further includes a determination unit that compares and determines the amount of quicksand per unit time and a water intake permissible threshold, and further includes a determination unit that compares and determines the amount of quicksand per unit time and a water intake permissible threshold, It is configured as a water intake control device for a hydroelectric power plant that controls the gate drive unit according to the result to open and close the water intake gate.
The determination unit is a water intake control device for a hydroelectric power plant that outputs a water intake permission signal for opening a water intake gate to the gate drive unit when the amount of quicksand per unit time is less than a water intake permission threshold. The quicksand amount measuring device according to any one of claims 1 to 5 further includes a determination unit that compares and determines the amount of quicksand per unit time with a water intake restriction threshold and a water intake permissible threshold, and further comprises: It is configured as a water intake control device for a hydroelectric power plant that controls a gate drive unit to open and close a water intake gate according to the determination result of the determination unit,
If the amount of quicksand per unit time exceeds the water intake limit threshold, the determination section outputs a water intake limit signal to close the water intake gate to the gate drive section, and the amount of quicksand per unit time exceeds the water intake limit threshold. A water intake control device for a hydroelectric power plant that outputs a water intake permission signal for opening a water intake gate to the gate drive unit when the water intake is less than an allowable threshold.