JP2579543Y2 - Cross flow turbine speed controller - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a speed control device for a cross-flow turbine having a plurality of guide vanes which are installed in a small hydroelectric power plant and each of which is independently controlled to open and close, and in particular, to opening of each guide vane. Regardless of degree, if each guide vane is closed individually or in combination ,
If the water pressure rise upstream of the water turbine
The present invention relates to a speed control device for a cross-flow turbine that is suppressed to a minimum .

[0002]

2. Description of the Related Art A cross-flow turbine has a drum-shaped runner, and a rotating shaft located at the center line of the drum is supported by casing, and the runner is rotated by flowing water introduced from a direction perpendicular to the rotating shaft. Driven small-capacity turbine, applied to small hydropower plants.

FIG. 2 is a side view conceptually showing a cross-flow turbine, and FIG. 3 is a perspective view showing a main part thereof, and the same parts as those in FIG. In FIG. 2 and FIG.
The case 2 is a runner supported on the case 1 by rotating shafts projecting from both ends thereof, and the case 3 is introduced into the runner 3 from the upper part of the case 1 through a penstock (not shown). This is a guide vane for adjusting the amount of flowing water.

In the cross-flow turbine constructed as described above, the flow rate of the flowing water introduced from above the casing 1 is adjusted by opening and closing the guide vanes 3 to enter the runner 2, and It hits the upper blade, passes through the runner 2 and hits the lower blade before being released out of the casing 1. In this way, the running water applies a rotational force to the runner 2 by an impulse on the upper blade and by a counterforce on the lower blade while passing through the runner 2, thereby rotating the runner 2 in a counterclockwise direction.

The rotation is transmitted to a generator (not shown) connected to the rotation shaft of the runner 2, and rotates the generator to convert the potential energy of the flowing water into electric energy. Therefore, the power generated by the generator can be adjusted by adjusting the flow rate of the flowing water.

[0006] The efficiency of the cross-flow turbine varies greatly depending on the flow rate of the flowing water introduced into the runner 2, but is considered so that high-efficiency operation can always be performed regardless of the flow rate. That is, for example, as shown in FIG. 3, the runner 2 has an integral structure but is divided into two parts 2a and 2b, and according to the division of the runner 2, the guide vanes 3 are also individually controlled to open and close. 2 of width la, lb (la <lb)
Is divided into three parts 3a and 3b.

Therefore, when the amount of flowing water that can be introduced into the water turbine is small, the opening and closing control of only the guide vanes 3a is performed. When the amount of flowing water is medium, the opening and closing control of only the guide vanes 3b is controlled. By controlling the opening and closing of the turbines 3a and 3b in combination, efficient water turbine operation can be realized.

When the guide vane is opened and closed, although not shown, the amount of water flowing in the penstock for guiding water to the casing 1 of the turbine is changed, and accordingly, the water pressure at the upstream of the water mouth of the turbine is changed. Changes occur. If the water pressure change is remarkable,
In this case, the load of a generator (not shown) connected to the water turbine is cut off due to an accident of a power system (not shown) to which the generator is connected, and the guide vanes 3 are forced to close suddenly. When the guide vane 3 is suddenly closed, the water pressure on the upstream side of the water turbine water port rapidly rises, and in the worst case, there is a concern that the penstock may be broken. Therefore, an allowable value for the water pressure increase generated when the guide vane is closed is determined in advance in consideration of the economic strength of the penstock, the economic rapid closing speed of the guide vane, and the like.

Considering the water turbine having the structure shown in FIG. 3, if the guide vanes are made to have the same rapid closing speed, when the guide vanes 3a are suddenly closed only when the amount of water is small, It is clear that the water pressure rise value generated when the combination of the guide vanes 3a and 3b is suddenly closed at the time of a large amount of water is larger in the latter case.

Accordingly, the rapid closing speed in controlling only the guide vanes 3b or in controlling the combination of the guide vanes 3a and 3b is adjusted in accordance with the rapid closing speed in controlling only the guide vanes 3a. Decide (same speed)
And only the guide vanes 3b or the guide vanes 3a and 3
At the time of sudden closing when combined with b, the increase in water pressure is larger than the above-mentioned allowable value, which is not preferable.

Conversely, in combination with the guide vanes 3a and 3b, only the guide vanes 3a are adjusted in accordance with the speed at the time of rapid closing.
Alternatively, if the sudden closing speed of only the guide vane 3b is determined,
When the guide vanes 3a or 3b alone are closed suddenly, the closing speed is low, and the turbine speed is higher than the permissible overspeed, which is not preferable in terms of water turbine protection.

[0012]

As described above, if the speeds at which a plurality of guide vanes of a cross-flow turbine having a plurality of guide vanes each of which are independently controlled to open and close are suddenly closed are the same, all the guides are controlled. When the vanes are suddenly closed at the same time, the water pressure on the upstream side of the water turbine water port may increase, and when the vanes are individually rapidly closed, the turbine speed may exceed the allowable range. Accordingly, the present invention sets the speed at which each guide vane is suddenly closed to an appropriate value, and increases the water pressure when all the guide vanes are suddenly closed at the same time, and when the sudden closing control of some of the guide vanes is performed. It is an object of the present invention to obtain a cross flow turbine speed control device in which the increase in speed does not exceed each allowable range.

[0013]

This invention SUMMARY OF THE INVENTION In order to achieve the above object, Te plurality of guide vanes speed controller smell <br/> crossflow water wheel having a each is independently controlled to open and close, said plurality All the guide vanes at the same time
The water opening area adjusted in unit time when
Both rise in water pressure upstream of the mouth and speed increase of the turbine are allowed
Set the guide vane to a specified value that does not exceed
Adjustment in unit time for quick closing control
So that the opening area of the spout is almost the same as the predetermined value.
Characterized in that the.

[0014]

When the guide vanes are controlled individually or in combination for quick closing control, if the opening area adjusted per unit time is substantially constant, the flow rate adjusted per unit time is also substantially constant. Neither the rise in the water pressure upstream of the water mouth of the turbine nor the increase in the speed of the turbine will exceed the respective allowable ranges.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a single-line diagram showing one embodiment of the present invention, and FIG.
Guide vanes, ie, each width is la,
lb is described as applied to a cross-flow turbine having a guide vane divided into two parts.

In FIG. 1, 3a. 3b has a width of l
The guide vanes a and lb. Each guide vane 3
Servo motors for individually controlling the opening and closing of a and 3b, for example, operating rods 5c and 5d of electric servo motors 5a and 5b.
Are connected to the upper ends of the arms 3c and 3d attached to the respective rotating shafts projecting right and left in the figure. 6a,
Reference numeral 6b denotes a servo amplifier, which is an electric servomotor 5a,
5b, and controls the driving of the electric servomotors 5a and 5b. 7a, 7b and 7c are guide vanes 3a and 3a, respectively.
3b is a speed setting device for setting the rapid closing speed (the rotation speed of the motors in the electric servomotors 5a and 5b), and is connected to the servo amplifiers 6a and 6b via the switching switches 8a and 8b. Is done.

As is apparent from the connection of the switching switches 8a and 8b shown in FIG. 1, when the switching contacts of the switching switches 8a and 8b are in the positions shown in the figure, the speed setting device 7a is connected to the guide vanes 3a. And the speed setting device 7b functions as a single quick closing control of the guide vane 3b. When the switching contacts of the switching switches 8a and 8b are in the switching position, the speed setting device 7b is used. 7a and 7b are excluded, and 7c is a guide vane 3a.
And 3b for quick closing control at the time of combination. As described above, different speed commands are given to the guide vanes 3a and 3b, respectively, at the time of the quick closing control alone or in combination.

At this time, the guide having the maximum width (1a + 1b)
In the case of quick closing control of Dvane (3a + 3b),
Upstream water pressure rise and turbine speed rise are both acceptable
Set the rapid closing speed so that it does not exceed
Assuming that Vc, another guide having a width of 1b (1b> 1a)
The rapid closing speed when only the vane 3b or only the guide vane 3a is determined by the following equation.

[0019]When combining guide vanes 3a and 3b
When the rapid closing speed is Vc, The rapid closing speed Vb when only the guide vane 3b is used is Vb = Vc × (1a + 1b) ÷ 1b _o The rapid closing speed Va when only the guide vane 3a is used is Va = Vc × (1a + 1b) ÷ 1a _o Here, Vc × (1a + 1b) is Opening per unit time
The rate of change of the area.

As described above, the speed setting devices 7a, 7b and 7c
Are set with rapid closing speeds Va, Vb, and Vc, respectively. Here, when the amount of flowing water is small,
When only the switch 3a is suddenly closed, the switching switch 8a
Is not changed, the state shown in the drawing is maintained, and the above-mentioned rapid closing speed Va set in the speed setting device 7a is supplied to the servo amplifier 6a via the switching switch 8a to operate the electric servo motor 5a. Thus, the guide vanes 3a are closed at the rapid closing speed Va regardless of the degree of opening of the guide vanes 3a.

When the amount of flowing water is medium, the guide vanes 3
In the case of performing the rapid closing control of only the b, the rapid closing speed Vb set in the speed setting unit 7b is changed to
The guide vane 3b is closed at the rapid closing speed Vb regardless of the degree of opening of the guide vane 3b by operating the electric servo motor 5b by supplying the servo vane 6b to the servo amplifier 6b via the switching switch 8b. .

When the amount of flowing water is large, the guide vanes 3
In the case of performing rapid closing control by combining a and 3b, the switching switches 8a and 8b are switched, and the above-mentioned rapid closing speed Vc set in the speed setting device 7c is applied to the servo amplifier via the switching switches 8a and 8b. The guide vanes 3a, 3b are closed at the rapid closing speed Vc regardless of the opening degree of the guide vanes 3a, 3b by operating the electric servo motors 5a, 5b.

[0023]

[Effects of the Invention] Although the present invention has been described in detail above,
According to the present invention, in a cross-flow turbine provided with a plurality of guide vanes each of which is independently controlled to open and close, when the guide vanes are individually or in combination, when the quick closing control is performed,
Since the opening area of the water port of the water turbine adjusted per unit time is made substantially constant, regardless of the degree of opening of each of the guide vanes, even if each of the guide vanes is suddenly closed, the upstream of the water port of the water turbine is opened. It is possible to provide a cross-flow turbine speed control device capable of suppressing an increase in the hydraulic pressure on the side and an increase in the speed of the turbine within respective allowable ranges. Furthermore, each guide base
No matter which guide vane is controlled to close rapidly, such as by itself or in combination, changes in the amount of water flow per unit time are equal.
The quick closing control operation is performed smoothly.

[Brief description of the drawings]

FIG. 1 is a single-line diagram showing an embodiment of the present invention.

FIG. 2 is a conceptual side view of a cross-flow turbine.

FIG. 3 is a perspective view showing a main part of FIG. 2;

[Explanation of symbols]

 1 ... casing, 2 ... runner, 3 ... guide vane, 5 ... servo motor, 6 ... servo amplifier, 7 ... speed setting device, 8 ... switching switch.

Claims (1)

(57) [Scope of request for utility model registration] A speed control device for a cross-flow turbine having a plurality of guide vanes each independently controlled to open and close.
Control the sudden closing of all of the plurality of guide vanes simultaneously.
The water opening area adjusted in unit time when
Both rise in water pressure upstream of the mouth and speed increase of the turbine are allowed
Set the guide vane to a specified value that does not exceed
Adjustment in unit time for quick closing control
So that the opening area of the spout is almost the same as the predetermined value.
Speed control device for a cross flow water turbine, characterized in that the.