JPH0720171Y2 - Jellyfish inflow prevention device - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is applied to an intake port of a facility that uses a large amount of seawater as cooling water, such as a nuclear power plant and a thermal power plant.
The present invention relates to a device for preventing jellyfish from flowing in.

(Prior art) Currently, in nuclear power plants and thermal power plants, a water channel (intake channel) is installed from the sea to the cooling device, seawater is introduced by a powerful pump, and turbine exhaust (low pressure after rotating the turbine) After being cooled, the high temperature steam is discharged into the sea.

In order to introduce seawater with such a powerful pump, jellyfish and other suspended matter near the inlet (intake) of the cooling water intake channel flow into the intake together with seawater, and as a result, those suspended matter are rough on the cooling device. Therefore, if the cooling device is stopped and the power generator is also stopped, the damage will be great.

Therefore, in the past, in order to prevent the inflow of suspended solids such as jellyfish, a dust removal device (a device that scoops up suspended solids clogging the iron grid screen by power or human power) was installed directly at the cooling water intake port. Abnormal occurrence of jellyfish in the suspended matter, if a large amount so that the sea surface becomes a jellyfish color, the dust remover can not be picked up a certain amount, it will not serve the role of dust remover, Due to a large amount of jellyfish that flowed into the cooling water intake channel and cooling device, and as a result, the cooling device and power generator were shut down, and households, factories, transportation facilities, traffic signals, etc. There was a risk of paralyzing for several hours or even days and causing a power outage panic. For this reason, conventionally, patrolling every few hours and landing jellyfish with nets and other equipment when a jellyfish group invaded was done manually, but such a procedure is not in time and the jellyfish raised Had a bad odor and could be odor pollution.

The present applicant has previously proposed a jellyfish inflow preventing device (No. Sho 56-51826) as shown in FIG. 5 in order to eliminate the above-mentioned problems.

An embodiment will be described below with reference to the drawings.

In the figure, 1 is the sea surface, 2 is the seabed, 3 is a quay wall, and 4 is a cooling water intake provided in the quay wall 3 in a tunnel shape.

This jellyfish inflow prevention device is, as shown in FIG. 5, a jetty that surrounds the intake port 4 on the sea surface 1 in front of the cooling water intake port 4.
11 protruding from the pier 11, and the seabed 2 outside the pier 11.
Fixed anchors 6 are installed at appropriate intervals on the upper side, and a rope 7 is stretched between the pier 11 and the fixed anchor 6 on the outside, and along this rope 7, the cable is inclined forward about 45 degrees. Net 8
Is stretched from the sea to near the seabed 2, and the lower edge 8a of this net 8 is
A lower opening 9 through which water flowing into the water intake 4 can pass is provided between the seabed 2 and the seabed 2. Normally, the height of this lower opening 9 is 1-2 m
Is appropriate. The size of the mesh 8 is preferably around 90 mm. Note that 13 is a handrail standing on the pier 11.

(Problems to be solved by the invention) As described above, the conventional jellyfish inflow prevention device is designed on the assumption that the vertical distribution of jellyfish in water is concentrated in the surface layer and not in the middle and bottom layers. Was there.

However, recent research has revealed that the vertical distribution of jellyfish in water is closely related to the illuminance in water. In other words, it was found that the jellyfish in the daytime are distributed near the surface layer, but after sunset, they are distributed in the surface layer and the middle layer, and especially after 10 pm, they are distributed almost evenly from the surface layer to the bottom layer.

The water in the intake channel is constantly flowing in except when the power station is stopped.Therefore, when a large amount of jellyfish is generated at night, the conventional jellyfish inflow prevention device uses a net that stretches around the intake. Not only the jellyfish passes through the lower opening and is sucked into the intake, but the meshes of the surface and middle layers are blocked by the jellyfish, which increases the flow velocity of the intake water flowing in through the lower opening and is generated by the water flow. The jellyfish in the middle layer and the surface layer may be drawn into the downward flow and flow into the intake port, causing an accident.

By the way, the inflow velocity in the lower opening near the intake is 0.2 m.
In the conventional jellyfish inflow prevention device in which the area of the opening is set to be about / sec to 0.3 m / sec, when the meshes of the surface and middle layers are all blocked as described above, the flow velocity in the lower opening Rises from 0.5m / sec to 0.6m / sec.
Therefore, in such a case, the jellyfish in the front and middle layers is also drawn into the increased water flow, and a part of the jellyfish flows into the intake.

(Means for Solving the Problem) In order to solve the above-mentioned problems, in the present invention, at the sea in front of the cooling water intake provided on the quay, the slope is inclined downward from the sea to near the seabed so as to surround the intake. A jellyfish inflow prevention device is constructed by tensioning the mesh and providing a lower opening between the bottom edge of the net and the seabed, and opening and closing the lower opening according to the vertical distribution of the jellyfish. To do.

(Operation) Since the device of the present invention is configured as described above, during the daytime, the jellyfish located on the surface layer in the water is stretched from the sea to near the seabed so as to be inclined downward to surround the intake. Can prevent it from flowing into the intake,
In this case, the seawater for cooling can be sufficiently taken in through the lower opening provided between the lower edge of the net and the seabed.

In addition, if a large amount of jellyfish is generated in the bottom layer of the water after sunset, it is possible to prevent the jellyfish from flowing into the intake by closing the lower opening described above. It is possible to prevent damage caused by stopping the cooling device and the power generator.

In addition, the jellyfish clusters accumulated on the front of the net are moved by being moved by the action of natural tidal currents and wave swells, thereby eliminating obstacles to the intake. At this time, if the water flow in the direction along the jellyfish prevention net is artificially generated, the jellyfish can be more effectively eliminated.

That is, according to the device of the present invention, even if an abnormally generated jellyfish group is distributed in the middle layer and the lower layer in addition to the surface layer in water, the jellyfish group is prevented from flowing into the intake port, and the jellyfish group is prevented. It is possible to prevent damage caused by the shutdown of the power plant cooling device and the power generation device, etc.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. In the figure, the same reference numerals as those used in the previous description denote the same elements.
That is, in the figure, 1 is the sea surface, 2 is the seabed, 3 is a quay wall, and 4 is a cooling water intake port provided in the quay wall 3 in a tunnel shape.

In the present embodiment, a jetty 11 is projectingly provided on the sea surface 1 in front of the cooling water intake 4 so as to surround the intake 4 via a column 12, and a suitable jetty is provided on the seabed 2 outside the jetty 11. Fixed anchors 6 are installed at intervals, and ropes 7 are stretched between the jetty 11 and the fixed anchors 6 on the outside, and along this ropes 7, a net 8 inclined at a forward angle of about 45 degrees is provided from the sea. It is stretched near the seabed 2, and a lower opening 9 through which water flowing into the intake port 4 can pass is provided between the lower edge 8a of the net 8 and the seabed 2. Usually, the height of the lower opening 9 is appropriately 1 to 2 m. Also the net 8
The size of the eyes is preferably around 90 mm. Note that 12a (see FIG. 2) is a diagonal member for reinforcing the column 12, and 13 is a jetty 11.
The handrail is installed upright.

Further, a net 14 that can close the lower opening 9 is provided so as to be openable and closable.

Any means may be used as the opening / closing means for the net 14, but an example of such means is shown in FIG.

That is, in FIG. 4, 8 is a net fixed along the rope 7 described above, 14 is a net for opening and closing the lower opening 9 provided below the lower edge 8a of the net 8, and its upper edge 14a is the net. Lower edge of 8
It is connected to a, and the lower edge 14b can be raised and lowered by a gliding device.

Reference numeral 15 is a pulley provided via a bracket 16 fixed to the fixed anchor 6, 17 is a pulley provided rotatably on a bracket 18 fixed to the pier 11, and 19 is a handle for the rotation.
Reference numeral 20 is a rope endlessly extended to the pulleys 15 and 17, and reference numeral 21 is a connecting fitting for connecting the rope 20 and the lower edge 14b of the net 14.

FIG. 4 shows a state in which the net 14 closes the lower opening 9, and if the handle 19 is rotated in the direction of arrow A from this state, the connecting metal fitting is connected via the rope 20 spanning the pulleys 15 and 17. twenty one
At the same time, the lower edge 14b of the net 14 moves as shown by the arrow B, the connecting fitting 21 moves to the position 21 ', and the lower edge 14b moves to 14b'.
Move to position. Then, in this state, the lower opening 9 is fully opened.

To close the lower opening 9 from the fully opened state, the handle 19 is rotated in the direction of arrow C. If you do this,
The lower edge 14b of the net 14 at the position 14b 'moves as shown by the arrow D and returns to the position of the solid line diagram. That is, the lower opening 9 is fully closed.

The lower opening 9 may be opened and closed depending on the distribution of the jellyfish in the vertical direction.

That is, the net 14 may be opened and closed manually by visually observing the condition of the water intake, or by installing an underwater television camera 22 as shown in FIG. 3 to monitor the jellyfish with this television camera. The opening / closing of the net 14 may be remotely controlled by electric power or the like, if necessary.

(Effect of the device) Since the device of the present invention is configured as described above, during the daytime, the jellyfish located at the surface layer in the water is stretched so as to surround the intake port 4 from the sea to the bottom of the sea in a downward slope. The net 8 provided can prevent the water from flowing into the intake port 4, and in this case, the seawater for cooling is sufficiently taken in through the lower opening 9 provided between the lower edge 8a of the net 8 and the seabed 2. be able to.

In addition, if a large amount of jellyfish is distributed in the bottom layer of the water after sunset, etc.
It is possible to prevent the jellyfish from flowing into the water intake port 4 by closing it by this so that damage due to the stop of the cooling device and the power generating device of the power plant can be prevented in advance.

In addition, the jellyfish clusters accumulated on the front of the net are washed away by the action of natural tidal currents and wave swells, and move to eliminate obstacles to the intake. At this time, if the water flow in the direction along the jellyfish prevention net is artificially generated, the jellyfish can be more effectively eliminated.

That is, according to the device of the present invention, even if an abnormally generated jellyfish group is distributed not only in the surface layer in water but also in the middle and lower layers, the jellyfish group is prevented from flowing into the intake port, and the jellyfish group is prevented. It is possible to obtain a practically excellent effect that damage due to the shutdown of the cooling device and the power generation device of the power plant due to the above can be prevented.

[Brief description of drawings]

 1 (a) is a plan view showing an embodiment of the device of the present invention, FIG. 1 (b) is its front view, FIG. 1 (c) is its side view, and FIG. 2 is of FIG. 1 (c). FIG. 3 is a detailed view showing a cross section, FIG. 3 is an explanatory view showing an opened state of the lower opening of FIG. 2, FIG. 4 is a front view showing an example of opening / closing means of the lower opening, and FIG. FIG. 1B is a front view and FIG. 1C is a side view showing an example. 1 …… Surface, 2 …… Sea floor 3 …… Wharf, 4 …… Intake port 6 …… Fixed anchor, 7 …… Rope 8 …… Mine, 9 …… Lower opening 11 …… Pier, 12 …… Post 13… … Handrails, 14 …… Nets 15 …… Pulleys, 16 …… Brackets 17 …… Pulleys, 18 …… Brackets 19 …… Handles, 20 …… Cables 21 …… Connecting fittings, 22… Underwater TV cameras

Claims (1)

[Scope of utility model registration request] 1. On the sea in front of the cooling water intake port provided on the quay, a net inclined forward and downward from the sea to near the bottom of the sea is stretched around the intake, and between the lower edge of the net and the bottom of the sea. A jellyfish inflow prevention device, characterized in that a lower opening is provided in the lower opening, and the lower opening can be opened and closed depending on the distribution of the jellyfish in the vertical direction.