JPH0723583Y2 - Intake device for once-through turbine - Google Patents

Description

[Detailed Description of the Invention] A. Industrial Application Field The present invention relates to the improvement of the once-through turbine, and is intended to improve the efficiency of the turbine.

B. Conventional technology A power generation system using a once-through turbine is known as a part of hydraulic energy recovery.

FIG. 7 shows a partially broken perspective view showing the structure of a conventional once-through turbine.

A runner 1 having a plurality of runner blades 1a rotated by the potential energy of water is rotatably supported by a rotary shaft 3 via a bearing 3a having a seal built in a casing 2. An upper nozzle 2a is provided between the casing 2 and the outer peripheral surface of the upper portion of the runner 1 to prevent water leakage and water flow scattering.
Is extended from the casing 2. An inlet pipe 4 is connected to the casing 2 on the upstream side of the runner 1, and a guide vane 5 for adjusting the amount of water entering the runner 1 can be opened and closed on the inlet side of the casing 2 corresponding to the outlet side of the inlet pipe 4. It is provided in. On the downstream side of the runner 1,
Another casing 6 is connected to the casing 2, and a water discharge pipe 7 is connected to the casings 2 and 6 so as to hang down. The water discharge pipe 7 is guided into the water in the water discharge garden. The water flowing in through the inlet pipe 4 is adjusted by the guide vanes 5 into the runner 1, is discharged from the outer periphery after rotating the runner 1, and is discharged into the water in the discharge garden through the water discharge pipe 7.

During operation of the water turbine, air is mixed into the discharged water and discharged, so that the pressure inside the water turbine chamber including the casings 2 and 6 becomes negative. This negative pressure state acts as a force for forcibly sucking in water from the inlet pipe 4, and consequently improves the efficiency of the water turbine. On the other hand, when the water pressure inside the water turbine chamber becomes negative, the water discharge surface in the water discharge pipe 7 rises. However, since the water discharge surface rises as the runner 1 is submerged, it is uncomfortable. A valve device 8 is provided in the casing 6 in order to properly operate the valve. That is, when the negative pressure in the turbine interior reaches a certain value, the valve device 8
Is opened to introduce air into the turbine to prevent the negative pressure in the turbine from exceeding a certain value.

C. Problems to be solved by the device The once-through turbine shown in Fig. 7 had the following problems.

In order to adjust the negative pressure in the turbine interior, it is necessary to supply air to the turbine interior by the valve device 8, and intake noise is generated, which causes noise. Therefore, a muffler is required.

When the water level in the discharge yard becomes higher than that of the water turbine due to a flood or the like, water may flow from the valve device 8 and infiltrate into the water turbine room.

There is a case where the water of the part which flows through the rotation shaft 3 side most and is discharged from the runner 1 is caught in the rotation of the runner 1 and is prevented from being discharged.

Water may be discharged from the valve device 8 when the flow inside the turbine changes suddenly, such as when the turbine starts or when the load changes suddenly.

The present invention has been made in view of the above circumstances, and provides an intake device for a once-through water turbine that supplies air in a water discharge yard to an idle portion of a runner, thereby preventing entrapment of water in the runner to remove air. And supply the water and air,
The purpose is to improve turbine efficiency.

D. Means for Solving the Problems The structure of the present invention for achieving the above-mentioned object is a runner in which a runner blade is arranged on a cylinder is rotatably supported in a water turbine casing, and water is generated by rotating the runner. In a once-through water turbine that discharges water to the discharge garden, the runner portion between the rear side in the rotation direction of the portion where water enters and the front side in the rotation direction of the portion where water is discharged is between the water surface upper portion of the discharge garden. And the intake flow rate adjusting valve is provided in the communication passage.

E. Function The air above the water surface of the discharge yard is sucked into the idle part of the runner after the flow rate is adjusted by the intake flow rate adjustment valve via the communication passage, and the negative pressure inside the water turbine chamber is prevented while blocking the entrainment of water in the runner. adjust. When the water level in the discharge yard becomes high, the intake flow rate control valve is closed to prevent water from flowing into the turbine interior.

F. Embodiment FIG. 1 shows a cross-section of a once-through turbine equipped with an intake device according to the first embodiment of the present invention, and FIG. 2 shows an enlarged view of an arrow II in FIG. The same components as those of the conventional once-through water turbine are designated by the same reference numerals, and duplicate description will be omitted.

The outlet of the water discharge pipe 7 opens into the water of the water discharge yard 11, and the casings 2 and 6 are mounted on the concrete floor 1 of the water discharge yard 11 via the mount 12.
Backed by 3. A lower flange 14 is welded and fixed to the water discharge pipe 7 on the water discharge yard 11, and an upper flange 15 is welded and fixed to the water discharge pipe 7 on the concrete floor 13. The lower flange 14 is provided with an air suction pipe 16 that opens above the water surface of the water discharge garden 11, and the upper flange 16 is provided with a water discharge pipe 7.
A pipe 17 is provided toward the outside. The pipe 17 is provided with a flow rate control valve 18 as an intake flow rate adjusting valve.
A discharge pipe 19 facing the runner 1 is provided at 18. The upper flange 15 and the lower flange 14 are connected by a connecting pipe 20 in a water discharge pipe 17. The tip of the discharge pipe 19 opens toward the idling portion 21 of the runner 1, that is, the rear side in the rotational direction of the portion where water enters and the front side in the rotational direction of the portion where water is discharged, and as shown in FIG. The air from the tube 19 is adapted to run along the direction of rotation of the runner 1.

In FIG. 1, the upper flange 15 and the lower flange 14 are connected by the connecting pipe 20, but the lower flange 14 is opened and a partition wall is provided inside the water discharge pipe 17 to surround the opening and the upper flange 15. A passage may be formed. By doing so, the water discharge pipe 17 can be reinforced, and it is economical because there is no need to provide a special supply member. Further, although the connecting pipe 20 is passed through the water discharge pipe 17, it may be provided outside the water discharge pipe 17.

In the once-through turbine, the water flowing from the inlet pipe 4 is adjusted by the guide vanes 5 into the runner 1, is discharged from the outer periphery after rotating the runner 1, and is discharged into the water in the discharge garden 11 through the discharge pipe 7. . Since the once-through water turbine mixes water and air in the runner 1 part, the water discharged from the water discharge pipe 7 has 20 to 30
% Of air is mixed, and the air floats on the discharge surface as bubbles.
Therefore, it is necessary to replenish the air because the air inside the water turbine is discharged through the water discharge pipe 7. The air shortage in the runner 1 portion is supplied through the discharge pipe 19, and the discharge flow rate of air is adjusted by the flow rate control valve 18. The air contained in the water discharged from the water discharge pipe 7 floats up in the water discharge garden 11, is sucked in from the air suction pipe 16, and is introduced again into the runner part 1 via the connection pipe 20, and the air is in the water turbine. And it will circulate through the discharge garden 11. By limiting the amount of air introduced from the discharge pipe 19 by the flow control valve 18, the inside of the water turbine becomes a negative pressure to form a water column in the discharge pipe 7, and the negative pressure sucks water from the inlet pipe 4. There is an effect, and there is an effect of effectively utilizing a part of the head on the discharge side and increasing a turbine output.

The air that has entered the turbine through the discharge pipe 19 enters the runner 1 and presses the boundary surface of the water as shown by the arrow in FIG. 1 to regulate the flow of the water. Further, as shown in FIG. 2, by introducing air with the discharge port of the discharge pipe 19 directed in the rotation direction of the runner 1, the water adhering to the runner blade 1a is blown off and the water jet of the next stage is blown in. Smooth the air flow and adjust the air flow inside the turbine. As a result, the turbulence of the flow of air and water in the runner 1 can be minimized and the turbine efficiency can be improved.

The air intake device described above does not require air supply to the room,
Quiet operation is possible without the generation of intake noise and no silencer is required. Further, even if the water level in the discharge garden rises, the flow control valve 18 is closed so that water does not flow back into the turbine.
Further, the flow of air and water is regulated, the amount of air mixed in the water is reduced, and the flow of water adhering to and caught in the runner 1 is blocked to improve the turbine efficiency. According to the experiment, it was confirmed that the efficiency was improved by 1.5% to 1.8% with a low head (head H _s = 2 m). In addition, there are no sudden changes in load and no water leakage at startup.
In addition, since air is circulated and used, it is possible to omit venting of the water discharge garden 11, and there is no emission of odor contained in the air.
Contaminated water and clean water (chlorinated gas treated water) can prevent the diffusion of odors contained in water.

Next, a second embodiment of the present invention will be described. FIG. 3 shows a cross section of a once-through turbine equipped with an intake device according to a second embodiment of the present invention.
FIG. 4 shows an enlarged view of an arrow IV portion in FIG.
The same parts as those in FIGS. 1 and 2 are designated by the same reference numerals, and a duplicate description will be omitted.

A partition wall 31 having a U-shaped cross section is provided inside the water discharge pipe 7, and a lower opening 33 of a passage 32 surrounded by the partition wall 31 and the water discharge pipe 7 is opened above the water surface of the water discharge garden 11. Further, the upper opening 34 of the passage 32 opens toward the idling portion 21 of the runner 1, and the passage 32
An opening / closing valve 35 as an intake flow rate adjusting valve is provided in the vicinity of the upper opening 34 of the. The partition wall 31 may be provided outside the water discharge pipe 7 and the passage 32 may be provided outside the water discharge pipe 7.

The structure of the on-off valve 35 will be described with reference to FIG. In the figure, reference numeral 36 denotes a valve body, and the base end of the valve body 36 is supported by the water discharge pipe 7 via an opening / closing pin 37, and the valve body 36 is provided with a clevius 38.
On the other hand, the water discharge pipe 7 is provided with an outer lid 39, and a screw shaft 40 is screwed into the outer lid 39. Clevius 38 at the tip of the screw shaft 40
A fork 41 for holding the
And is rotatably supported by the Clevius 38 through the long hole 43. In the figure
Reference numeral 44 is a handle for turning the screw shaft 40.

By turning the handle 44, the screw shaft 40 will move to the arrow Y in the figure.
The valve element 36 opens and closes in the range from fully open to fully closed by reciprocating in the direction. The amount of air can be arbitrarily adjusted by adjusting the interval δ by the valve body 36.

In this intake device, air is sent into the water turbine through the passage 32, and the opening / closing valve 35 limits the amount of air introduced.
The same action and effect as the intake device shown in the figure are achieved. Further, since all the members of this intake device are provided in the water discharge pipe 7, the installation and disassembly are easy, the number of parts is small, and the reliability against water leakage is high.

Next, a third embodiment of the present invention will be described. FIG. 5 is a cross section of a once-through turbine equipped with an intake device according to a third embodiment of the present invention,
FIG. 6 shows the valve opening / closing mechanism. The same members as those in the first and second embodiments are designated by the same reference numerals, and duplicate description will be omitted.

Since the amount of water of the once-through turbine is adjusted by the opening of the guide vane 5, the flow of water and air can be adjusted better by adjusting the intake amount to follow the opening of the guide vane 5. That is, if the intake air amount is adjusted with the guide vane 5 fully open, the supplied intake air amount may become excessive when the guide vane 5 is closed, and the head H _s may not be effectively recovered. In the intake system of the third embodiment, the opening degree of the guide vane 5 and the supplied intake air amount are adjusted in conjunction with each other.

The side wall 45 is provided in the water discharge pipe 7, and the side wall 45 allows the passage 46
Are formed. The passage 46 is open to the upper part of the water surface of the discharge garden 11 and to the idle part 21 of the runner 1. A valve 47 is provided near the upper opening of the passage 46 as an intake flow rate adjusting valve that opens and closes in conjunction with opening and closing of the guide vane 5. In the figure, 5a is a guide vane support shaft, and 47a is a valve shaft.

The opening / closing mechanism of the valve 47 will be described with reference to FIG. In the figure, reference numeral 48 denotes a guide vane servo, and the tip of the guide vane servo 48 is connected to a guide vane operating lever 50 via a pin 49. That is, the guide vane 5 is opened and closed via the guide vane operating lever 50 by the expansion and contraction of the guide vane servo 48. The guide vane operating lever 50 is provided with a connecting fitting 51, and one end of an adjusting connecting device 53 is pivotally supported by the connecting fitting 51 via a fork fitting 52. In the figure, reference numeral 54 denotes a valve operating arm attached to the valve shaft 47a, and the other end of the adjustment connecting device 53 is pivotally supported by the valve operating arm 54 via a fork fitting 55. That is, when the guide vane servo 48 extends as shown by the arrow in the figure, the guide vane operating lever 50 rotates clockwise, and the adjustment connecting device 53 is pulled up obliquely upward to the left. When the adjusting coupling device 53 is pulled up, the valve operating arm 54 rotates counterclockwise and the valve 4 moves through the valve shaft 47a.
7 will be opened in the opening direction.

The ratio of the open / close relationship between the guide vane 5 and the valve 47 is determined by the connecting fitting 51
Position, the length of the valve operating arm 54 and its set angle. In addition, the escape of excessive operation at the fully opened and fully closed positions of the valve 47 is absorbed by the adjusting coupling device 53.

In this intake device, the air is sent into the water turbine through the passage 46, and the introduction amount of the air is limited by the valve 47, so that the same operation and effect as those of the first and second embodiments are achieved. Since the opening and closing of the valve 47 is performed in conjunction with the opening and closing of the guide vanes 5, there is no waste can effectively make the most of fall H _s. By providing the number of valves 47 according to the number of guide vanes 5, the head H _s can be effectively used even when the amount of water is extremely small.

The above-described intake device (first to third embodiments) can be selected and used in combination depending on the shape of the once-through turbine, the installation environment, the use conditions, and the like.

G. Effect of the Invention In the intake device of the circulating water turbine of the present invention, since the water surface of the discharge yard and the idle part of the runner communicate with each other through the communication passage, the air in the discharge yard can be supplied to the idle part of the runner. . As a result,
By preventing the entrainment of water in the runner and supplying air into the turbine interior, the flow of water and air can be adjusted to improve turbine efficiency. In addition, since air is circulated between the water discharge yard and the water turbine room, there is no need to replenish the air or remove air from the water discharge yard, which enables quiet operation without generation of intake noise. Further, since the intake flow rate adjusting valve is provided, there is no backflow of water even when the water level rises, and water leakage can be prevented when the load suddenly changes.

[Brief description of drawings]

FIG. 1 is a sectional view of a once-through turbine equipped with an intake device according to a first embodiment of the present invention, and FIG. 2 is an enlarged view of an arrow II in FIG.
FIG. 3 is a sectional view of a once-through turbine equipped with an intake device according to a second embodiment of the present invention, and FIG. 4 is an enlarged view of an arrow IV in FIG.
FIG. 5 is a sectional view of a once-through turbine equipped with an intake device according to a third embodiment of the present invention, FIG. 6 is an explanatory view of its valve opening / closing mechanism, and FIG.
The figure is a partially broken perspective view of a conventional once-through turbine. In the drawings, 1 is a runner, 7 is a water discharge pipe, 11 is a water discharge garden, 16 is an air intake pipe, 17 is a pipe, 18 is a flow control valve, 19 is a discharge pipe, 20 is a connection pipe, 21 is an idle part, 31 is Partition wall, 32 is a passage, 35 is an on-off valve, 45
Is a side wall, 46 is a passage, and 47 is a valve.

Claims (1)

[Scope of utility model registration request] 1. A through-flow turbine that rotatably supports a runner, in which a runner blade is arranged on a cylinder, in a turbine casing, and water that is rotated by the runner is discharged to a discharge garden. The runner portion between the rear side in the direction of the water and the front side in the rotating direction of the portion where water is discharged is communicated with the upper surface of the water surface of the water discharge yard through a communication passage, and the intake flow rate adjusting valve is provided in the communication passage. An intake device for a once-through water turbine, which is characterized by being provided with.