JPH0826846B2 - Cross-flow turbine control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a control method for a cross flow turbine, which is capable of removing clogging of foreign matter.

B. Summary of the Invention The present invention is a split guide vane type cross-flow turbine having two guide vanes, in which guide vanes clogged with foreign matter are opened to allow the foreign matter to flow down.

C. Conventional technology Since the equipment of small-capacity turbines is small, foreign matter mixed in the water being used may clog the turbine. In this case, it is necessary to stop the turbine and remove the foreign matter. was there.

There is a cross flow turbine as a small capacity turbine. In this type of cross-flow turbine with one guide vane, the thickness of the guide vane is large, so foreign matter such as cloth cuttings, leaves, and chips is rarely caught in the guide vane. Since the water flows from the outer diameter side to the inner diameter side and then flows again to the outer diameter side, the foreign matter is less likely to be entangled because the foreign matter is shaken off from the runner due to the centrifugal force of the water flow and the runner.

By the way, since the split guide vane type cross-flow turbine operates at high efficiency, foreign matter may be clogged. Here, the structure and operation of the split guide vane type cross flow turbine and the mode of clogging of foreign matter will be described.

FIG. 2 shows a split guide vane type cross flow turbine. As shown in this figure, this type of cross-flow turbine has two guide vanes 1a and 1b. The guide vane 1a controls opening / closing of 1/3 of the water channel, and the guide vane 1b controls 2/3 of the water channel. Control the opening and closing. The water introduced through the inlet pipe 2 enters the runner 3 from the outer diameter side of the runner 3, and the runner 3 again
To the outer diameter side and is drained through the draft pipe 4. The shaft 5 of the runner 3 is rotatably supported by the bearing of the bearing housing 6 and rotates. Reference numeral 7 is a partition plate, 8 is a housing, 9 is an air introduction valve, and 10 is a casing.

In the split guide vane type cross-flow turbine having such a configuration, high efficiency operation is performed according to the high efficiency operation characteristics shown in FIG. That is, when the flow rate is low, the guide vane 1b is fully closed and the opening degree of only the guide vane 1a is adjusted.
1/3 guide vane operation, when the flow rate slightly increases, fully close the guide vane 1a and adjust the opening of only the guide vane 1b 2/3 guide vane operation, when the flow rate is sufficiently high, guide vane 1a, Move 1b together to adjust the opening. Perform 3/3 guide vane operation.

D. Problems to be Solved by the Invention In the above-mentioned high-efficiency operation, since the operation mode is changed according to the flow rate, the guide vane may be closed when the operation mode is switched.

In this closing process, as shown in FIG. 4, the gap (water channel) between the closed guide vane 1 and the casing 2 may be clogged with foreign matter 11, and the guide vane 1 may not be closed. In such a case, conventionally, an abnormal torque (operation force) detection device provided in the operation mechanism of the guide vane operates to stop the water turbine.

In addition, as shown in FIG.
11 may become clogged and the guide vane 1 may become inoperable. In this case, since the opening of the guide vane 1 is large, the water is allowed to flow, and the water turbine is rotated up to the unrestrained speed and idles, causing the water to flow unnecessarily.

Switching of the operation mode, which causes clogging of foreign matter, occurs when the amount of water increases or decreases, and particularly when the water level increases, foreign matter around the flow channel tends to flow due to rainfall or water increase, and such foreign matter clogging tends to occur.

In order to prevent the inflow of foreign matter, the eyes of the screen provided in the water channel should be made small, but this makes the screen clogged even with small dust and the like, and maintenance of the screen becomes complicated, which leads to operational efficiency. Is reduced. Therefore, the eyes of the screen can remove large foreign matter,
The current situation is that only small things are allowed to pass.

In view of the above-mentioned conventional technique, the present invention provides a control method for a cross-flow turbine that can cause a foreign substance to flow down if it becomes clogged.

E. Means for Solving Problems The present invention which solves the above problems, when the closing operation is performed, foreign matter is clogged, and when the operation force of the guide vane becomes excessive, the clogged guide vane is removed. It is characterized in that the guide vane is controlled to be opened and the other guide vane to be closed so as to compensate for the difference in water amount.

F. Examples Hereinafter, the method of the present invention will be described in detail.

In the method of the present invention, operation control of the cross-flow turbine shown in FIG. 2 is performed according to the operation flow shown in FIG. That is,
When the operating force of a guide vane operating device (not shown) that operates the guide vanes 1a and 1b individually (generally, an electric servomotor device is used) is a steady value, high efficiency operation is performed. High-efficiency operation means, as shown in Fig. 3, when the amount of flowing water becomes small, the wide guide vane 1b is fully closed to adjust the opening degree of the narrow guide vane 1a so that the amount of flowing water becomes medium. Then, the guide vane 1a is fully closed to adjust the opening of the guide vane 1b, and when the amount of flowing water becomes large, the opening adjustment of the guide vanes 1a and 1b is performed together.

In the high-efficiency operation described above, when the guide vane is closed in the process of closing the guide vane, the guide vane cannot be closed and the operating force of the guide vane operating device becomes excessive as shown in FIG. 4, and an excessive operating force is detected. It also indicates that the operating force has become excessive. The detection time or the number of times of detection of this excessive operation force is counted, and when the count value is equal to or less than the set value, the foreign matter clogging operation is performed.

In the foreign object clogging operation, the guide vane 1a, 1b, which cannot be closed and whose operating force is excessive, is fully opened. For example, when shifting from the 1/3 guide vane operation to the 2/3 guide vane operation, the guide vane 1a is closed and the guide vane 1b is opened. If the guide vane 1a that was closed at this time is not closed due to foreign matter clogging and the operating force becomes excessive, the guide vane that was about to be closed
Reversely open 1a to fully open it. In this way, when the guide vanes 1a are fully opened, the foreign substances clogged in the guide vanes 1a often flow down. In this example,
In order to fully open the guide vane 1a, which should normally be fully closed, the opening of the guide vane 1b is adjusted within the margin range so as to compensate for the difference in water amount.

After the above-mentioned foreign matter clogging operation, when the required time has elapsed, the guide vanes that have been fully opened due to foreign matter clogging are closed. In the above example, since the foreign matter is clogged, the guide vane 1a which is fully opened by the foreign matter clogging operation is closed. When closing the clogged guide vane in this way, return to high-efficiency operation when the operating force does not become excessive, and when the operating force becomes excessive, detect excessive operating force again and perform foreign object clogging operation. .

If the clogged foreign matter does not flow down even after the foreign matter clogging operation, the foreign matter clogging operation is repeated. During this repetition, if the detection time or the number of detections of the excessive operation force exceeds the set value, it is displayed that the foreign matter clogging is serious. If this message is displayed, the monitor will either restart the operation with a foreign object clogged, or fix the position of the guide vane clogged with a foreign object and continue with only the other guide vane, so-called single guide vane operation, or stop the turbine. Or to choose freely.

It should be noted that the high-efficiency operation may be returned immediately after the required time has elapsed since the foreign material clogging operation was performed. At the time of returning to high efficiency operation in this way, the relationship between the opening degree of the guide vanes 1a, 1b and the flow rate is not in a state of high efficiency operation, so that the guide vanes 1a, 1b can be operated in high efficiency. The opening is operated. When an excessive operating force of the guide vane is detected during the opening operation, the foreign object clogging operation is performed again, and when the excessive operating force is not detected, the highly efficient operation is started.

Further, if an excessive operating force is detected, a so-called grab operation may be performed before the foreign object clogging operation. The grab operation is an operation of repeatedly opening and closing the guide vanes rapidly.

G. Effects of the Invention According to the present invention, as described in detail with reference to the embodiments above, according to the present invention, when the foreign matter is clogged, the clogged guide vane is opened to allow the foreign matter to flow down.

(1) The turbine can be effectively operated because the turbine is not stopped due to clogging of foreign matter.

(2) Since the generator circuit is not opened while water is flowing through the water turbine, the speed does not rise to an unrestrained speed and wear of the equipment is not promoted.

(3) The energy of water can be effectively converted into electric power without the loss of water due to the stop of the water turbine.

(4) Except for a particularly bad condition (as shown in FIG. 5), it is not necessary to perform the foreign matter removing work, and labor saving in maintenance can be achieved.

(5) By the count (number of times, time) of excessive operation force,
It is possible to check the water condition and take appropriate measures (such as modifying the screen). (6) In the initial plan, we would like to make the mesh of the screen coarse for easy maintenance, but to make it smaller from clogging with foreign matter. It is a thing. By adopting this method, even if a slightly rough screen is adopted, it does not cause any inconvenience in operation, so boldly adopt a coarse screen, and in the unlikely event of inconvenience (5) take appropriate measures after the fact. Can be given. This is an important feature for machines that deal with the natural world, where precise preliminary examination is difficult.

(7) When the operating force of the guide vane becomes excessive, it is caused by opening the guide vane of the operating force becomes excessive and opening the guide vane of the operating force becoming excessive. Since the other guide vane is closed at an opening that offsets the increase in the flowing water amount, the amount of water supplied to the runner (total amount of water) does not change. Therefore, even during foreign matter clogging operation, the internal pressure in the iron pipe supplying water to the water turbine does not rise and the iron pipe is not damaged. In addition, effective operation can be performed without wasting water. Even if the guide vane clogged with foreign matter is operated to open rapidly, the other guide vane closes rapidly, so there is no concern about the increase in iron pipe internal pressure. It can also be opened to allow foreign matter to flow down reliably.

[Brief description of drawings]

FIG. 1 is a flow chart showing the operation of the method of the present invention, FIG. 2 is a perspective view showing a cross-flow turbine with a part thereof removed, and FIG. 3 is a characteristic chart showing high efficiency operation, FIGS. 4 and 5. The figure is a schematic diagram showing a state in which foreign matter is clogged. In the drawing, 1a and 1b are guide vanes, and 3 is a runner.

Claims (1)

[Claims] 1. A cross-flow turbine that adjusts the amount of water supplied to the runner by controlling the opening and closing of two narrow and wide guide vanes, when the operating force of each guide vane is a steady value. When the amount of water flowing to the turbine is small, the wide guide vane is fully closed to adjust the opening of the narrow guide vane, and when the amount of water flowing to the turbine is medium, the narrow guide vane is fully closed. The wide guide vane opening is adjusted to adjust the opening of the narrow and wide guide vanes when the amount of water flowing to the turbine becomes large, and highly efficient operation is performed to control the amount of water supplied to the runner. , If the operating force of the guide vanes is too large, open the guide vane of the one with excessive operating force and the running water generated by opening the guide vane of the one with excessive operating force. At the opening to offset the increase in volume The method of cross-flow turbines and performing foreign matter clogging operation controls to gradually close the square of the guide vanes.