JPS6211332Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a leakage water recovery device for returning water leaking out of a casing along the rotation axis of a runner in a cross-flow water turbine into the casing.

The structure of a typical cross-flow turbine is shown in Fig.
As shown in the figure, the runner 1, which is rotated by the potential energy of the water, is rotatably supported within the casing 2. The runner 1 is supported relative to the casing 2 by supporting the rotating shaft 3 of the runner 1 on the casing 2 side with a bearing 4 attached.
An inlet pipe 5 is connected to the casing 2 on the upstream side of the runner 1, and a guide vane 6 that can be opened and closed is provided on the inlet side of the casing 2 corresponding to the outlet side of this inlet pipe 5 to adjust the amount of water entering the runner 1. Another casing (cover) 7 is connected to the casing 2 on the downstream side of the runner 1, and a water discharge pipe 8 that hangs down from these casings 2 and 7 is connected to this water discharge pipe 8. This water discharge pipe 8 is led underwater. Water flowing in from the inlet pipe 5 is adjusted by the guide vane 6 and enters the runner 1, and the runner 1
After rotating, the water is discharged from its outer periphery and discharged through the discharge pipe 8
is discharged into the water through

During operation of this water turbine, air is mixed into the discharged water and discharged, resulting in a negative pressure inside the water turbine chamber made up of the casings 2, 7, and the like. This negative pressure state is caused by the inlet pipe 5
This acts as a force that forcibly sucks in water from the water, thereby improving the efficiency of the water wheel. On the other hand, when the water turbine chamber becomes negative pressure, the water discharge surface in the water discharge pipe 8 rises, but it would be bad if the water discharge surface rose to the extent that the runner 1 was submerged, so the water discharge surface was adjusted by adjusting the negative pressure inside the water turbine chamber. A valve device 9 is provided on the cover 7 in order to make it appropriate. In other words, when the negative pressure in the water turbine chamber reaches a certain value, the valve device 9 opens to guide air into the water turbine chamber, thereby preventing the negative pressure in the water turbine chamber from exceeding a certain value.

However, when the water turbine starts operating, a negative pressure within the water turbine chamber cannot be established until the water discharge pipe 8 is filled with water, and the pressure inside the water turbine chamber becomes positive due to the inflow of water. This pressure causes water to leak along the rotating shaft 3. In order to prevent this water from leaking, the leaking part, that is, the part through which the rotating shaft 3 passes through the casing 2, has been filled with gland packing. However, although water leakage can be prevented by providing a gland packing, frictional torque is generated between the gland packing and the rotating shaft 3, which adversely affects the rotation of the runner 1. In addition, the gland packing wears out, so retightening is required.
Various problems arise during maintenance and inspection, such as the need to replace them when they become obsolete.

The present invention was developed in view of the above-mentioned current situation, and aims to prevent water leakage along the rotation axis of a cross-flow water turbine by means other than a seal, thereby eliminating various problems caused by using a seal. The purpose is to

The gist of the present invention to achieve the above object is to house a runner in a casing that forms a water turbine chamber, support the rotating shaft of the runner in the casing, and furthermore, when the water turbine chamber reaches a negative pressure above a certain value, In a cross-flow water turbine in which the casing is provided with a valve device that opens to introduce air into the water turbine chamber, an annular frame surrounding the rotating shaft is integrally formed with the casing on the outside of a portion of the casing through which the rotating shaft passes. At the same time, a drain hole is provided at the bottom of the annular frame, a water receiver is provided below the drain hole, and the bottom of the water receiver communicates with a position higher than the highest water level in the water turbine chamber. It is located in the water leakage recovery device of cross-flow water turbines.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a leakage water recovery device according to the present invention will be described in detail based on an embodiment shown in the drawings.

FIGS. 2A and 2B and FIG. 3 show the main parts of one embodiment. In addition, please refer to FIG. 1 for the entire configuration of the cross-flow water turbine. An annular frame 10 surrounding the rotating shaft 3 is provided outside a portion of the casing 2 housing the runner 1 through which the rotating shaft 3 of the runner 1 passes. This annular frame 10 forms an air chamber 11 around the rotating shaft 3, and this air chamber 11 and the portion of the casing 2 surrounding the rotating shaft 3 form a labyrinth. A drain hole 12 is provided at the bottom of the annular frame 10, and a container-shaped water receiver 13 is provided below the drain hole 12 integrally with the casing 2. There is a drain hole 1 at the bottom of this water receptacle 13.
4 is open, and a pipe 16 is connected thereto via a nipple 15.

On the other hand, a communication hole 17 is provided in the upper part of the casing 7 of the casings 2 and 7 forming the water turbine chamber, and a case 18 connected to the communication hole 17 is attached via a packing 19. A partition plate 20 is provided in this case 18 whose upper end is open, and a valve device 21 is provided on this partition plate 20. The valve device 21 includes a valve body 23 that opens and closes a hole 22 provided in the partition plate 20 from below, and a valve body 23 that opens and closes a hole 22 provided in the partition plate 20 from below.
The valve stem 24 is attached to the valve stem 3 and extends upward through the hole 22, and a spring 26 is provided between the support plate 25 screwed to the upper end of the valve stem 24 and the partition plate 20. In addition, 27 is a gasket provided on the contact side of the valve body 23 with the partition plate 20;
29 is the partition plate 20 as a guide for the valve stem 24.
A guide supported by 30 is a cover that covers the valve device 21 and the case 18 above. According to this valve device, when the pressure inside the water turbine reaches a certain value or more, the suction force pulls down the valve body 23, the water turbine chamber communicates with outside air through the hole 22, and air flows into the water turbine room. That's what I do. The operating pressure of this valve device 21 can be adjusted by moving the support plate 25 and changing the spring force of the spring 26. Incidentally, a suction hole 31 is provided below the partition plate 20 in the case 18 . Then, the pipe 16 is inserted into this suction hole 31.
are connected via nipples etc.

When the cross-flow turbine starts operating, the pressure inside the turbine chamber increases, and water leaks from the shaft penetrating portion of the casing 2. However, since the portion of the casing 2 surrounding the rotating shaft 3 and the air chamber 11 constitute a labyrinth, the amount of leakage is smaller than in the conventional case. The leaked water enters the air chamber 11 and falls through the drain hole 12 at the bottom of the air chamber 11 and flows into the water receiver 13 below.
Enter and store here. The internal volume of the water receiver 13 is sufficient to accommodate the amount of water that leaks until the water discharge pipe 8 is filled with water and a negative pressure is established in the water turbine chamber. When the discharge pipe 8 is filled with water and the inside of the water turbine becomes negative pressure, the water in the water receiver 13 is drained through the drain hole 14, the pipe 16, and the suction hole 31 due to the action of the negative pressure.
and is sucked back into the water turbine chamber (inside the casings 2 and 7) through the communication hole 17. In the drawing, the routes of water leakage and recovery are indicated by arrows A, B, and C. Water tray 1
After all the water in 3 has been sucked out, air is sucked into the water turbine chamber through the same route. Then, when the negative pressure increases further and the amount of air suctioned through the drain hole 14, pipe 16, and suction hole 31 becomes insufficient, the valve device 21 is activated, that is, the valve body 23 is moved by the spring force of the spring 26. It is pulled down against the pressure, and air is sucked into the water turbine chamber through the hole 22 and the communication hole 17.

In addition, from the drain hole 14 of the water receiver 13 to the suction hole 3
If a check valve is provided on the way to point 1, backflow of water can be prevented. Further, the suction hole 31 to which the pipe 16 is connected may be provided directly in the casing 2 or 7 separately from the valve device 21. Basically, suction hole 3
1 may be provided at a position within the water turbine chamber that will not be submerged in water, that is, at a position higher than the highest water level.

As described above in detail based on one embodiment, the leakage water recovery device according to the present invention can collect water leaking from the shaft penetrating portion of the casing of a cross-flow turbine by removing the negative water generated inside the casing during operation of the water turbine. Since water is returned to the casing using pressure, there is no need for a gasket to prevent water leakage.
Maintenance and inspection problems will also be eliminated.

[Brief explanation of the drawing]

FIG. 1 is a partially exploded perspective view of a cross-flow water turbine, and FIGS. 2A, B, and 3 are partial sectional views showing essential parts of an embodiment of the present invention. In the drawing, 1 is a runner, 2 and 7 are casings,
3 is a rotating shaft, 8 is a water discharge pipe, 10 is an annular frame, 11 is an air chamber, 12 is a drain hole, 13 is a water receiver, 14 is a drain hole, 16 is a pipe, 17 is a communication hole, 21 is a valve device , 31 are suction holes.

Claims (1)

[Scope of utility model registration request] A cross-flow turbine has a casing which contains a runner and supports the rotating shaft of the runner by said casing, and further has a valve device which opens when the negative pressure in the turbine chamber reaches a certain value or more to introduce air into the turbine chamber. A water leakage recovery device for a cross-flow turbine is characterized in that an annular frame which surrounds the rotating shaft is provided integrally with the casing outside the part of the casing through which the rotating shaft passes, a drain hole is provided at the bottom of the annular frame, a water receiver is provided below the drain hole, and the bottom of the water receiver is connected to a position higher than the maximum water level in the turbine chamber.