JPH0240532A - Method and apparatus for measuring sediment concentration of influent water in hydraulic machine - Google Patents

Abstract

PURPOSE:To shorten a measuring time largely and to make it possible to perform measurement at a low cost by providing a water column incorporating sediment and a pure water column which does not incorporate sediment, and measuring the pressure difference between the lower ends of both water columns with the differential pressure. CONSTITUTION:A draining valve 11 is opened. Water in an upper water tank 4 is guided into a pipe 9 for water incorporating sediment. The water is drained through a draining pipe 12. After the pipe 9 is filled, the draining valve 11 is closed. Aqueduct water 7 is supplied into a pure water pipe 8 from the outside. The upper end of the pipe 8 is aligned with the water surface of the water tank 4. This can be achieved readily by opening the water supply port for the water 7 and making the water overflow into a container-like float 6. In this way, the liquid column in the pipes 9 and 8 are prepared at the same height. Thereafter, a differential pressure DELTAP' in a differential pressure gage 10 is read. A sediment concentration C' for the measured differential pressure DELTAP' is obtained from the relationship between a differential pressure DELTAP and a sediment concentration C which are measured and prepared beforehand. When the concentration C' exceeds an allowable concentration Ca which is determined from the life of a water turbine, the operation of the water turbine is stopped.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method and device for measuring sediment concentration in inflow water from a hydraulic machine, and particularly to a method for measuring sediment concentration in inflow water from a hydraulic machine, and particularly for a hydroelectric power plant installed in a river with a high sediment content. The present invention relates to a method and apparatus for measuring the sediment concentration of water flowing into a hydraulic machine, which is suitable for measuring the sediment concentration of water flowing into a hydraulic machine.

[Conventional technology]

Measurement of the concentration of water containing sediment is normally carried out as in water.

In other words, water containing sediment is collected into a cylinder, and the volume (
vs+vw) and weight (Ws+W-).

Next, the earth and sand are precipitated, and the earth and sand are taken out and dried to separate them into moisture-free earth and sand, and the weight of the earth and sand is Ws, and the volume is Vs.
Measure.

from now, or Calculate.

Here, Vs: volume of earth and sand, vW: volume of water, Ws: weight of earth and sand, and Ww: weight of water.

In addition, devices for measuring the density or specific gravity of liquids that are related to devices that use a liquid column and a pressure gauge include 1, for example:
JP 50-80162, JP 50-57272, JP 56-151956, JP 61-8224
The techniques described in each publication of No. 9 are known.

[Problem to be solved by the invention]

Although the conventional technology described in the first half above has high measurement accuracy, it takes a lot of time to measure, and there are problems in that it is difficult to start and stop the hydraulic machine as needed.

In addition, in the related known examples described in the latter half of the above, sufficient consideration was not given to the fact that the use of two differential pressure gauges or pressure gauges makes the device complicated, the measurement accuracy is low, and the cost is high. Ta.

The present invention has been made to solve the above-mentioned problems in the prior art, and it is possible to significantly shorten the time required for measurement without significantly reducing measurement accuracy, and to measure sediment concentration in water flowing into hydraulic machines at low cost. The object is to provide a method and a measuring device.

[Means to solve the problem]

In order to achieve the above object, the method for measuring the sediment concentration of water flowing into a hydraulic machine according to the present invention is based on the height difference between the upper water tank water surface of the water containing soil, which becomes the water flowing into a hydraulic machine, and the intake part of a hydraulic machine. The pressure acting on the lower end of the liquid column and the differential pressure acting on the lower end of the liquid column of fresh water with the same height difference are measured, and from the relationship between the above differential pressure verified in advance and the concentration of the sediment-containing water, I am trying to find the sediment concentration.

In detail, one tube of the 0-shaped manometer, which has a communication part at the height of the hydraulic machine water suction part, has a water surface level at the top of the liquid column above the water tank water surface of the sediment-containing water that becomes the water flowing into the turbine. The soil-containing water is drained, and fresh water with a water surface level at the top of the liquid column is injected into the other pipe, and a differential pressure gauge is installed in the communication section at the bottom to measure the differential pressure. The sediment concentration of the sediment-containing water is determined from the relationship between the above differential pressure verified in advance and the concentration of the sediment-containing water.

In addition, in order to achieve the above object, the device for measuring the sediment concentration of inflow water from a hydraulic machine according to the present invention has a water tank for water containing sediment, which becomes inflow water from a hydraulic machine. A container-shaped float containing fresh water is floated on the water surface of the water tank, and the U-shaped pipe has a communication part at the height of the water absorption part of the hydraulic machine. A type manometer is provided, one pipe is connected to the water tank for the sediment-containing water to serve as a conduit for the sediment-containing water, and the other pipe is connected to the container-shaped float containing the fresh water to serve as a fresh water conduit. A differential pressure gauge is installed in the communication section.

It should be noted that the above purpose is not to separate and extract the sediment from the sediment-containing water and calculate the concentration by examining the amount.
A water column of sediment-containing water and a water column of fresh water that does not contain sediment are established.1
By measuring the pressure difference between the lower ends of both water columns using differential pressure, and determining the sediment concentration from the relationship between the pre-verified differential pressure and sediment concentration.

achieved.

[Effect]

The operation of the above technical means will be explained with reference to FIGS. 3 and 4.

FIG. 3 is a conceptual diagram of a liquid column connected to a differential pressure gauge showing the effect of the present invention, and FIG. 4 is a diagram showing the relationship between the differential pressure of the liquid column and the sediment concentration.

Generally, the weight concentration C of water containing soil and sand is defined as follows.

Here, Ws: Weight of sediment contained in a unit volume of sediment-containing water Ww: Weight of unit volume of sediment-containing water Meanwhile, the specific weight γ of the sediment-containing water is as follows.

Here, vs: volume of sediment in unit volume of sediment-containing water vW: volume of unit volume of sediment-containing water. Also, the specific weight γS of sediment and the specific weight γ of fresh water are expressed as vs 1. From equations (1) to (4), the weight concentration C of the earth and sand is as follows.

On the other hand, as shown in FIG. 3, when measuring the pressure difference ΔP at the lower end of the liquid column between the conduit 9 of earth and sand-containing water with the liquid column height H and the conduit 8 of fresh water whose upper end is open to the atmosphere, the pressure gauge 10 is used. , we get the following function:

ΔP=(γ−γw) H...(6) Here, ΔP: Differential pressure at the bottom of the liquid column H: height of liquid column Substituting equation (6) into equation (5) yields.

becomes. Here, in one fixed river, the specific weight γS of sediment is almost constant, and γw and H are known, so the concentration C can be determined by measuring ΔP.

That is, the relationship between the differential pressure ΔP and the concentration C becomes a diagram as shown in FIG. Therefore, if such a relationship is verified theoretically or experimentally in advance, the differential pressure ΔP
The soil concentration C' can be determined when '.

For example, H = 40 m, γ- = 1000 kgf /
ni', vs = 3000 kg f / m'', concentration C = 3%, ΔP = 0.082 kgf/d, and the measurement differential pressure head Δh = 0.82 m. Then, Δh/H = 2 .05%, and the measurement accuracy of the differential pressure gauge is 0.
．． 1 to 0.05% is easily obtained and can be sufficiently measured.

〔Example〕

Embodiments of the present invention will be described below with reference to FIG. 1, FIG. 2, and FIGS. 5 to 7.

FIG. 1 is a block diagram of a device for measuring the sediment concentration of water flowing into a water turbine according to an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between the differential pressure of the liquid column and the sediment concentration of the sediment-containing water. be.

In Fig. 1, 1 is a water turbine related to a hydraulic machine, 2 is a generator, 3 is a penstock pipe, 4 is a water tank for water containing sediment, 5 is a suction pipe, and is a reference for the water surface of the water tank 4 and the water turbine inlet. Hydroelectric power plants are constructed by maintaining a height difference (liquid column height) H.

Reference numeral 6 denotes a container-shaped float containing fresh water that maintains the water level at the same level as the water surface of the water tank 4, and this container-shaped float 6 is floated on the water surface of the water tank 4 containing soil and sand. Reference numeral 7 denotes a tap water supply port disposed on the upper part of the container-shaped float 6.

8 has an upper end connected to the bottom of the container-shaped float 6 and a lower end connected to the bottom of the container-shaped float 6.
The fresh water conduit that serves as the communication part of the pipe constitutes the liquid column height H of fresh water. Reference numeral 9 denotes a sediment-containing water conduit whose upper end is connected to the water supply MI4 for sediment-containing water and whose lower end is a communication part of the U-shaped pipe, and constitutes a liquid column height H of the sediment-containing water. Reference numeral 10 denotes a differential pressure gauge installed in a communication section between the fresh water conduit 8 and the earth and sand-containing water conduit 9.

Next, a more detailed configuration will be explained with reference to FIG.

River water containing sediment flows into the water tank 4.

The water flows into the water wheel 1 through the hydraulic pipe 3 and flows out through the suction pipe 5 to rotate the generator 2.

The water tank 4 for sediment-containing water has an inlet end 9a connecting a sediment-containing water conduit 9 constituting a liquid column of sediment-containing water; A container-shaped float 6 that constitutes a liquid column of fresh water is installed. The inlet end 9a may be provided on the bottom or side surface of the water tank 4.

The container-shaped float 6 floats on the surface of the water containing sediment, and the container is supplied with fresh water such as tap water, so that the surface of the fresh water in the float and the water surface of the water tank 4 are at the same level as the water surface of the water containing sediment. is set to .

A flexible conduit 8a is connected to the lower part of the container-shaped float 6, so that it can follow the float even when the water surface changes, and this conduit 8a forms one end of the fresh water conduit 8.
At least a portion inside the water tank 4 is made flexible.

The fresh water conduit 8 and the earth and sand-containing water conduit 9 are generally made of flexible materials such as steel pipes and polyethylene tubes, but the flexibility of the flexible conduit 88 section is particularly taken into consideration.

A differential pressure gauge 10 is connected to the U-shaped tubular communication portion at the lower end of both grooved pipes 8 and 9. The lowest end of the sediment-containing water conduit 9 is a drain pipe 12
A drain valve 11 is provided.

Next, a measurement procedure (measurement method) using the sediment concentration measurement device for water turbine inflow water having such a configuration will be explained.

The drain valve 11 is opened, and the water in the water tank 4 is led to the soil-containing water conduit 9 and discharged from the drain pipe 12. After the inside of the conduit 9 is filled with water containing earth and sand, the drain valve 11 is closed.

On the other hand, the fresh water conduit 8 is supplied with tap water 7 from the outside, and the upper end (fresh water liquid upper end) of the fresh water conduit 8 is adjusted to the water surface of the clean water tank 4 . This can be easily done by opening the tap water supply lower and causing the tap water to overflow into the container-shaped float 6.

After the liquid column in the soil-containing water conduit 9 and the liquid column in the fresh water conduit 8 are prepared at the same liquid column height in this way, the differential pressure ΔP' of the differential pressure gauge 10 is read. Then, as shown in FIG. 2, the sediment concentration C' with respect to the measured differential pressure ΔP' is determined using the relationship between the differential pressure ΔP and the sediment concentration C, which has been previously verified and prepared.

When the obtained sediment concentration C' is equal to or higher than the allowable concentration Ca determined based on the life of the water turbine, the operation of the water turbine is stopped.

In this way, to measure the sediment concentration of the sediment-containing water flowing through the water turbine, open the drain valve 11, drain the water from the drain pipe 12 for several minutes, then close the drain valve 11, and measure the differential pressure. The concentration can be determined in a very short time.

According to this embodiment, the sediment concentration of the sediment-containing water flowing into the water turbine can be measured in a short time, with high accuracy, and at a relatively low cost.

If this embodiment is applied as part of a water turbine operation maintenance method that complies with operation standards regarding sediment concentration, it becomes easy to periodically measure sediment concentration, which has the effect of extending the life of the water turbine.

Next, FIG. 5 is a block diagram of main parts of a control system of a sediment concentration measuring device according to another embodiment of the present invention, and FIG. 6 is a flowchart showing processing contents of a control computer.

In FIG. 5, the same reference numerals as in FIG. 1 indicate equivalent parts, and devices not shown in FIG. 5 are equivalent to those in FIG. 1.

In the sediment concentration measuring device shown in Fig. 5, the sediment-containing water conduit 9
and at the lower end of the liquid column of fresh water conduit 8.

Each has a drain pipe 12a, 12b portion, and is provided with a drain valve 11a, llb, which is operated by a signal from a computer 13 related to an arithmetic control means, respectively, and a fresh water conduit 8, a sediment-containing water conduit 9, in order to measure the sediment concentration. The operation of injecting fresh water and soil-containing water into the tank is performed according to instructions from the computer 13.

The processing procedure of the computer 13 is as shown in FIG. That is, the preliminary test or set data is read into the computer 13. The data is based on the specific weight of soil γ8. Specific weight of fresh water γ1. These are liquid column height H2, drain valve opening time TV, differential pressure gauge pressure settling time Tfl, volume concentration CV, allowable concentration C&, etc.

Sediment-containing water conduit9. Drain valves 11a, l at the bottom of the fresh water pipe 8
lb is opened for a time Tv, and when each conduit is filled with earth and sand-containing water and fresh water, each drain valve is closed. Wait for the differential pressure gauge pressure settling time TR and read the differential pressure gauge output ΔP.

The differential pressure signal thus measured by the differential pressure gauge 10 is taken into the computer 13, and the sediment concentration C is determined based on the relationship shown in FIG. 2 stored in the computer (7).
Calculated using the formula. The results are outputted by an output device, and if the obtained soil concentration is equal to or higher than the operating permissible concentration, an alarm signal 14 or a water turbine stop command signal 15 is issued.

According to the embodiment shown in FIG. 5, the same effect as the embodiment shown in FIG. 1 can be obtained automatically under computer control.

Next, FIG. 7 is a configuration diagram of a float section of a sediment concentration measuring device according to still another embodiment of the present invention. In the figure, the first
Components with the same reference numerals as in the figures indicate equivalent parts, and devices not shown in FIG. 7 are equivalent to those in FIG. 1.

In FIGS. 7(a) and (b), 16 is a water supply valve provided in the water supply lower, 17 is a float, and this float 17 is composed of a float 17a floating on the fresh water surface 20 of the container-shaped float 6 and a water containing sediment. The lever 1 moves the float 17b floating on the water surface 19 of the water tank 4.
8 are equally supported on the side wall of the container-shaped float 6, and the opening degree of the water supply valve 16 is controlled in conjunction with the vertical movement of these floats 17a and 17b. 21 is a flexible pipe that supplies tap water.

In the state shown in FIG. 7(a), the water surface 19 of the water tank 4 and the fresh water surface 20 of the container-shaped float 6 are at the same level, and the lever 18 connecting the floats 17a and 17b is kept horizontal.

From this state, as shown in FIG.
When it becomes lower than 9, the float 17a is at the bottom and the float 17b is at the top, the lever 18 is tilted, the water supply valve 16 is opened, and fresh water is injected from the water supply lower.

Eventually, as shown in FIG. 7(a), when the fresh water level 20 and the water level 19 of the sediment-containing water reach the same level, the water supply valve 16 is closed and the injection of fresh water into the container-shaped float 6 is stopped. Therefore, the fresh water surface 20 at the top of the clear water column is always
is at the same level as the water surface 19 at the upper end of the liquid column of sediment-containing water, and the height H of both liquid columns relative to the differential pressure gauge is the same, making it possible to measure the sediment concentration with high accuracy.

In addition, although each of the above embodiments describes an example of a method and an apparatus for measuring the sediment concentration of inflow water to a water wheel of a hydroelectric power plant, the present invention is not limited to the water wheel.

It can also be applied to pump equipment to the extent that similar effects are expected.

〔Effect of the invention〕

As described above, according to the present invention, there is provided a method and a measuring device for measuring the sediment concentration of hydraulic machine inflow water, which can significantly shorten the time required for measurement and perform measurement at low cost without significantly reducing measurement accuracy. It is something.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a device for measuring the sediment concentration of water flowing into a water turbine according to an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between the differential pressure of the liquid column and the sediment concentration of the sediment-containing water. Fig. 3 is a conceptual diagram of a liquid column connected to a differential pressure gauge showing the effect of the present invention, and Fig. 4 is a conceptual diagram of a liquid column connected to a differential pressure gauge.
Figure 5 is a diagram showing the relationship between the differential pressure in the liquid column and the sediment concentration.
A main part configuration diagram of a control system of a sediment concentration measuring device according to another embodiment of the present invention, FIG. 6 is a flowchart showing processing contents of a control computer, and FIG. It is a block diagram of the float part of the sediment concentration measuring device concerning this. DESCRIPTION OF SYMBOLS 1... Water wheel,... Water tank, 6... Container-shaped float, 7... Water supply port, 8... Fresh water conduit, 8a... Flexible conduit, 9... Sediment-containing water Conduit, 10... Differential pressure gauge,
11. lla. 11b...Drain valve, 13...Computer, 16.
... Water supply valve, 17, 17 a, 17 b ... Float, 18-... Lever! Figure 1 - Water turbine differential pressure, ap Coral water valve ■ Figure Fukuni (Otsu-) (b)

Claims (1)

[Scope of Claims] 1. Pressure acting on the lower end of the liquid column of sediment-containing water based on the height difference between the upper water tank water surface of the sediment-containing water that becomes inflow water of the hydraulic machine and the intake part of the hydraulic machine, and fresh water with the same height difference. The method is to measure the differential pressure between the pressure acting at the lower end of the liquid column and to determine the sediment concentration of the sediment-containing water from the relationship between the pre-verified differential pressure and the concentration of the sediment-containing water. Sediment concentration measurement method. 2. One pipe of the U-shaped manometer, which has a communication part at the height of the water intake part of the hydraulic machine, has a sediment-containing manometer that has a water surface level at the top of the liquid column at the water tank water surface of the sediment-containing water that becomes the water flowing into the turbine. Water is injected into the other pipe, and fresh water with a water surface level at the top of the liquid column, which is the same as the water level in the water tank, is injected into the other pipe. A differential pressure gauge is installed in the lower end communication section to measure the differential pressure, and the pressure is verified in advance. A method for measuring the sediment concentration of water flowing into a hydraulic machine, characterized in that the sediment concentration of the sediment-containing water is determined from the relationship between the above-mentioned differential pressure and the concentration of the sediment-containing water. 3. A water tank for water containing sediment, which will be inflow water from the hydraulic machine, is installed so that the water level of the water tank maintains a predetermined difference in height from the water turbine inlet, and a container containing fresh water that maintains the water level at the same level as the water surface of this water tank. A U-shaped manometer having a communication part is installed at the height of the water absorption part of the hydraulic machine, and one pipe is connected to the water tank for the sediment-containing water to drain the sediment-containing water. An apparatus for measuring sediment concentration in inflow water from a hydraulic machine, characterized in that the other pipe is connected to the container-shaped float containing fresh water to form a fresh water pipe, and a differential pressure gauge is provided at a communicating portion of both pipes. 4. In the item described in claim 3, a tap water inlet is provided at the upper part of the container-shaped float containing fresh water, so that even if the water level in the water tank changes, the water level of the fresh water surface in the container-shaped float is maintained. In order to maintain the water level at the same level as the water level in the water tank, a water supply valve that opens and closes in conjunction with the top and bottom of the float is provided, and the fresh water conduit connected to the container-shaped float is constructed such that at least the portion inside the water tank is a flexible pipe. A device for measuring sediment concentration in inflow water from a hydraulic machine, characterized by: 5. In the item described in claim 3, a drain valve and a drain pipe are provided at the lower part of the conduit for sediment-containing water, and the soil-containing water to be measured can be injected into the conduit for sediment-containing water by opening and closing the drain valve. A device for measuring sediment concentration in inflow water from a hydraulic machine, characterized in that: 6. In any one of claims 3 to 5, the drain valve at the bottom of the conduit for water containing sediment and the differential pressure gauge at the conduit communication part are connected to an arithmetic processing device, and the sediment-containing water is determined from the differential pressure. A device for measuring sediment concentration in water flowing into a hydraulic machine, characterized in that a control circuit is configured to calculate the sediment concentration in water, and to issue a sediment concentration output alarm and a water turbine stop command.