JPS5825870B2 - Hydroelectric power plant cooling water supply system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water supply device that takes water from a water penstock using a pressure reducing device and supplies pressurized water to equipment.

When water is taken from a high-head penstock in a hydroelectric power plant and the water is supplied as cooling water to a lubricating oil cooler for a bearing or a cooler for cooling air in a forced air-cooled generator, the schematic configuration of the conventional system is shown in Figure 1. A water supply device as shown is used.

That is, in FIG. 1, a water turbine 1 converts the energy of high-pressure water flowing in from a penstock 2 into rotational power, and generates a generator 3.
is driving.

The water that has been depressurized by applying energy to the water turbine 1 passes through the suction pipe 4 and is discharged into the discharge channel 5.

Lubricating oil coolers 6 and 7 are installed on the bearings of the water turbine 1 and generator 3.
．． 8 is provided, and the generator is provided with an air cooler 9.

Water is taken from the penstock 2 and passed through the on-off valve 10 to the pressure reducing device 11
The cooling water whose pressure has been reduced to the supply pressure is branched off to the on-off valves 12, 13, 14 of the respective coolers 6, 7, 8.9.
．． 15 and is supplied to coolers 6,7°8.9.

The water that has passed through the coolers 6, 7, 8.9 is transferred to the flowing water relay 16.1.
7.18.19 and is discharged into the suction pipe 4.

Note that when these water flow relays 16, 17, 18, and 19 detect that water has stopped flowing, they stop the water turbine 1 for protection.

In the above-mentioned device, if water scale builds up or gets clogged in the coolers 6, 7, 8.9 and the discharge piping from these, the amount of cooling water passing through the pressure reducing device 11 may decrease or disappear. do.

The pressure reducing device 11 uses a throttle valve or pressure reducing pipe that is less likely to malfunction due to rust or water scale, and has a small cross-section of the passage, or one that reduces the pressure by flow.
If the amount of cooling water passing through decreases or disappears, the pressure of the cooling water after the pressure reducing device will become higher than the supply pressure, and there is a risk of damaging the coolers 6, 7, 8, 9, piping, etc.

For this purpose, a safety valve 20 is connected between the pressure reducing device 11 and the coolers 6.7 and 8.9, and when the pressure of the cooling water after the pressure reducing device 11 rises above a certain level, the safety valve 20 releases the cooling water. It is released into the atmosphere to suppress the increase in pressure of the pressure water passing through the pressure reducing device.

However, if the safety valve is used for a long period of time, the movable parts of the safety valve will become stuck due to rust and water scale and will not move.
The disadvantage is that there is a risk of damaging pipes and pipes.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and provide a cooling water supply system for a hydroelectric power plant that does not cause damage to coolers or piping.

According to this invention, the above object is to provide a piping between a pressure reducing device and a cooler with a water head higher than the supply cooling water pressure Φ water head to the cooler and a constant water head than a water head corresponding to the pressure resistance of the cooler and piping. When connecting a rising safety pipe that is open to the atmosphere and located at a lower height than the water head subtracting A distant relative can be achieved by providing the riser safety pipe with an inner diameter of a size that does not exceed the above-mentioned certain water head.

Embodiments of the present invention will be described below based on the drawings.

In the case of the cooling water supply system for a hydroelectric power plant according to the present invention shown in FIG. 2, the pressure reducing device 11 and the on-off valves 1213. A rising safety pipe 21 is connected between them, and an opening 22 of this rising safety pipe 21 to the atmosphere is connected to a cooler 6.7,
8.9 higher than the water head of the supply pressure to the coolers 6.7, 8
．． It is installed at a height lower than the water head obtained by subtracting a certain water head from the water head of the pressure that the piping can withstand.

Further, the riser safety pipe 21 has a size such that when water is sent only to the riser safety pipe 21 from the pressure reducing device 11, the resistance water head generated with respect to the amount of water flowing through the riser safety pipe 21 does not become larger than the above-mentioned constant water head. It has a large inner diameter.

Therefore, the cooling water reduced in pressure by the pressure reducing device 11 is transferred to the cooler 6.
, 7, 8.9 and the piping, the cooling water at the inlet of the cooler 6, 7, 8.9 is at the supply pressure, so
The supply pressure can be maintained without being released from the opening 22 of the rising safety pipe 21.

In addition, even if water scale accumulates in the cooler 6゜7.8.9 or the piping or the water stops flowing at all due to blockage, the pressure reducing device 1
The water from 1 passes through the rising safety pipe 21 and is discharged to the open port 22. At this time, the sum of the resistance water head of the rising safety pipe 21 and the height of the open port 22 is equal to Since the water head is lower than the pressure that can be withstood, the cooler 6.7.8
．． 9 and the pressure of the cooling water in the pipes can be kept below a tolerable pressure.

Moreover, since the rising safety pipe 21 has no moving parts, even if it is used for a long period of time, there is no risk of it becoming inoperable due to rust or water scale, and damaging the coolers 6, 7, 8.9 and piping.

FIG. 3 shows a schematic configuration of a cooling water supply system for a hydroelectric power plant according to another embodiment of the present invention.

This hydroelectric power plant is an underground type with a surge tank 23 in the spillway 5.
is provided.

The open port 22 at the upper end of the rising safety pipe 21 is the surge tank 2
3, there is no need to separately install a drainage channel for water discharged from the rising safety pipe.

Further, in the case of a device having a surge tank, a configuration as shown in FIG. 4 can be used.

In this underground hydroelectric power plant, there is a gate 24 at the outlet of the suction pipe 4.
During maintenance or inspection, the gate 24 is closed and the pump 25 drains the suction pipe 4.

A portion of this drainage piping and the piping of the cooling water supply system similar to that shown in FIG. 3 is shared, thereby saving piping.

Opening the on-off valves 10, 12, 13, 14 and 15 and closing the on-off valves 26 and 27 will result in the same connection as shown in Figure 3.
Water can be taken in from the penstock 2 and supplied to the coolers 6, γ, 8, and 9.

Further, by closing the on-off valves 10.12, 13, 14.15 and opening the on-off valve 26.27, water in the suction pipe 4 can be drained into the surge tank 23 at a lower position by the pump 26.

The water supply device according to the present invention configured as described above has a water head in the piping between the pressure reducing device and the cooler that is higher than the water head of the pressure of the cooling water supplied to the cooler and is higher than the water head corresponding to the pressure resistance strength of the cooler and the piping. Connect a rising safety pipe that is open to the atmosphere and located at a height lower than the water head after subtracting a certain water head, and
Since the riser safety pipe has an inner diameter large enough to prevent the resistance water head generated in the riser safety pipe from becoming larger than the above-mentioned certain water head when water is sent only to the riser safety pipe from the pressure reducing device, the cooler The pressure of the cooling water in the safety pipes can always be kept below a tolerable pressure, and since there are no moving parts in the safety pipes, even if used for a long period of time, rust and water scale may cause the pipes to stop working and damage the equipment and pipes. There's no fear.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a conventional cooling water supply system for a hydroelectric power plant, FIG. 2 is a schematic diagram showing an embodiment of the cooling water supply system for a hydroelectric power plant according to the present invention, and FIG. 3 is a schematic diagram of the present invention. FIG. 4 is a schematic diagram showing a modification of the cooling water supply system for a hydroelectric power plant shown in FIG. 3. FIG. 1: Water wheel, 2: Penstock pipe, 4: Suction pipe, 8.9: Cooler, 11: Pressure reducing device, 21: Rising safety pipe, 23: Surge tank, 25: Drainage pump.

Claims (1)

[Claims] 1 In a cooling water supply system for a hydroelectric power plant that takes water through a pressure reducing device from the middle of a penstock pipe and supplies this water as cooling water to a cooler via piping, the piping between the pressure reducing device and the cooler. The rising safety pipe is located at a height higher than the head of the cooling water pressure supplied to the cooler and lower than the head equivalent to the pressure resistance of the cooler or piping minus a certain head, and is open to the atmosphere. The rising safety pipe has an inner diameter of such a size that the resistance head generated in the rising safety pipe does not exceed the above-mentioned certain water head when the water is connected to the rising safety pipe and water is sent only to the rising safety pipe from the pressure reducing device. Features: Cooling water supply system for hydroelectric power plants.