JPH1161787A - Preventive device against air-draw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent whirlpools from arising near the seawater surface through a water stream generator installed in the sea and prevent air from being drawn into the water stream generator, by connecting a number of spherical floats with a rope and laying them on the surface of the sea. SOLUTION: A water stream generator 20 is installed at the intake opening for seawater in a thermal power station or the like to reject jelly fish. A number of propellers 21 are fixed to the support frame 107 installed on the bottom 02 of the sea, in the water stream generator 20. And signal lamps 103 are installed on the surface 01 of the sea. A number of spherical floats 1 made of synthetic resin are connected in series by a rope 2 to form a contact body 10 with whirlpools and laid on the surface 01 of the sea. Both ends of the rope 2 are connected to the signal lamps 103. In this way, the whirlpools generated near the surface of the sea by the water stream generator 20 come into toutch with the contact body 10 and they are attenuated to disappear. And hence, air suction into the water stream generator 20 resulting from the whirlpools can be prevented. And when contact cloths to contact whirlpools, fitted with weights are suspended from the floats 1, the attenuating effect of whirlpools is further increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air draw preventing device, and more particularly to an air draw preventing device suitable for preventing an air draw of a jellyfish eliminating water flow generating device provided at a seawater intake port in a thermal power plant or the like.

[0002]

2. Description of the Related Art Generally, in thermal power plants and the like, seawater is taken and used as cooling water for equipment. In order to prevent marine organisms such as jellyfish (hereinafter, abbreviated as "jellyfish") from flowing into the seawater intake port, a jellyfish elimination water flow generator is provided. As shown in FIGS. 5A to 5D, the water flow generating device is configured by mounting a plurality of propeller devices 21 on a support frame 107 provided on the seabed 02 and installed at a water intake 03.

[0003] A water flow generator 20 is installed in a sea area having a water depth of 10 m or less.
When the propeller device 21 is operated when the
As shown in FIG. 5 (a), a vortex 100 is generated near the sea surface 01, and the vortex 100 becomes large in time [FIG. 5 (b)]. Will be sucked into. (This phenomenon is called air draw (air suction)) [FIGS. 5 (c) and 5 (d)].
Reference numeral 103 in FIG. 5 indicates the sea surface almost immediately above each support frame 107.
A marker light floating at 01 is shown, and each marker light 103 is connected to each support frame via ropes 104 and 106 via sinks and floats 105, respectively. Reference numeral 101 denotes a bubble released to the offshore 04.

[0004]

For a water flow generator (for jellyfish elimination), an air draw (suction of air)
Serious problems related to the performance of the device, such as damage to the device (cavitation of the propeller) and reduced function (reduced thrust, reduced jellyfish removal capability), may be caused. The present invention
It is an object of the present invention to provide an air draw preventing device which can prevent an air draw which may cause an important problem for a water flow generating device by eliminating a vortex generated with the operation of the water flow generating device.

[0005]

According to the present invention, there is provided an air draw prevention device for a jellyfish elimination water flow generating device, wherein a vortex contact member formed by connecting a large number of floating bodies in a daisy chain is provided on a water surface almost immediately above the water flow generating device. , Provided substantially parallel to the water flow generating device as a means for solving the problem. In addition, a vortex contact cloth is hung on the floating body to solve the problem.

In the present invention, the vortex generated by the operation of the water flow generating device gradually approaches the vortex contact body while increasing in size. . Further, by suspending the vortex contact cloth on the floating body, the contact area of the vortex contact body with the vortex increases, thereby increasing the vortex annihilation effect.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of an air draw prevention device according to a first embodiment of the present invention; FIG. FIGS. 3 (a) to 3 (d) are front views of the floating body, and FIGS. FIG. 4 is a front view of a main part of the air draw prevention device according to the second embodiment. 1 to 4, the same reference numerals as those in FIG. 5 indicate substantially the same members.

First, a first embodiment will be described with reference to FIGS. In FIG. 1, reference numeral 1 denotes a floating body, and the floating body 1 has a through hole 3 at the center of a substantially spherical molded product (a commercially available “buoy”) made of synthetic resin as shown in FIG. Is formed.

[0009] A large number of the floating bodies 1 having such a configuration are daisy-chained by a rope 2 inserted into a through hole 3 formed in the center of each floating body 1, thereby forming a vortex contact body 10. The vortex contact body 10 is attached to two marker lights 103 floating on the sea surface at both ends of the rope 2, and is laid on the sea surface almost in parallel with the water flow generator 20.

Each of the marker lights 103 is connected to a pair of support frames 107 erected on the seabed 02 to support the water flow generating device 20 by ropes 104 and 106 via sinks 105. The water flow generating device 20 attached between the two support frames 107 is provided with a large number of propeller devices 21.

As shown in FIGS. 3 (a) to 3 (d), the vortex contact body 10 is provided on the sea surface 01 almost directly above the water flow generating device 20 or slightly above the water flow generating device 20 in parallel with the water flow generating device 20. One or a plurality of rows (one row in the figure) are laid.

When the water flow generator 20 is installed in a sea area within a depth of 10 m, the vortex 100 [FIG. 3 (a)] generated near the sea surface 01 with the operation of the water flow generator 20 gradually increases. While approaching the vortex contact body 10 [FIG. 3 (b)], it comes into contact with the floating body 1 of the vortex contact body 10 [FIG. 3 (c)].

The vortex 100 gradually becomes smaller by contacting the floating body 1 and eventually disappears (FIG. 3D). Vortex 10
By eliminating 0, it is possible to prevent the suction of air (air draw) into the water flow generator 20 together with the vortex.

The tide is reversed at the time of rising tide and at the time of falling tide.
Regardless of the tidal current in either direction, the vortex 100 will gradually become smaller as it comes into contact with the floating body 1 and will eventually disappear.
It has been confirmed in hydraulic tests (model test of 1/20) and tests in actual sea areas.

In the case of the first embodiment, the vortex contact body 10 is
Since a large number of floating bodies 1 can be easily constructed by connecting beads in a rosary with ropes 2, and the construction on the sea surface can be performed by using the existing sign lamp 103, an air draw prevention device can be obtained at low cost. When a plurality of rows of the vortex contact bodies 10 are provided, the contact area between the vortex 100 and the floating body 1 increases, so that the vortex annihilation effect, that is, the air draw prevention effect can be enhanced.

Next, a second embodiment will be described with reference to FIG. In the second embodiment, the vortex contact body 10 is
A large number of floating bodies 1 connected in a rosary by ropes 2 and floating bodies 1
And a cloth-like vortex contact cloth 4 such as vinyl, which is hung from the cloth.

Further, in order to keep the vortex contact cloth 4 substantially vertical in seawater, a plurality of weights 5 are attached to arbitrary positions of the vortex contact cloth 4. Similarly to the first embodiment, the air draw prevention device of the second embodiment is also arranged in a row or substantially in parallel with the water flow generation device 20 on the sea surface almost directly above the water flow generation device 20 or slightly near the intake side. Multiple rows are laid. Therefore, the vortex 100 generated by the operation of the water flow generator 20 comes into contact with both the floating body 1 and the vortex contact cloth 4, and the contact area between the vortex and the vortex contact body 10 increases. Thereby, the vortex annihilation effect can be enhanced.

The height of the vortex contact cloth 4 is determined by the water flow generator.
It is needless to say that the swirl contact cloth 4 is set to a size that does not get caught in the water flow generator 20 in consideration of the installation water depth, output, and the like of the 20.

In the case of the second embodiment, the vortex annihilation effect is greater (as compared with that of the first embodiment), so that the number of laid rows can be reduced as compared with the case of the first embodiment.

The air draw prevention device according to the second embodiment is also inexpensive because it has a simple structure and is easy to lay on the sea surface, similarly to the first embodiment, and can obtain a large vortex eliminating effect. it can.

[0021]

As described in detail above, according to the air draw prevention device of the present invention, the following effects can be obtained. (1) The vortex generated due to the operation of the water flow generator can be made to disappear by contacting a floating body forming a vortex contact body,
This can prevent air from being sucked into the water flow generator. (2) By increasing the contact area between the vortex and the vortex contact body by suspending the vortex contact cloth on the floating body, the vortex annihilation effect can be enhanced.

[Brief description of the drawings]

FIG. 1 is a front view showing an air draw prevention device as a first embodiment of the present invention.

FIG. 2 is a front view showing the floating body.

FIGS. 3 (a) to 3 (d) are front views for explaining the vortex annihilation action.

FIG. 4 is a front view showing a main part of the air draw prevention device according to the second embodiment.

FIG. 5 (a) is a front view showing a conventional jellyfish eliminating water flow generator. (b) Front view showing the state of generation of the vortex. (c) Front view showing the state of being sucked into the vortex water flow generating device. (d) The side view in the AA arrow of a figure (c).

[Explanation of symbols]

 01 Sea surface 02 Sea floor 03 Sea water intake 04 Offshore side 1 Floating body 2 Rope 3 Through hole 4 Vortex contact cloth 5 Weight 10 Vortex contact body 20 Water flow generator 21 Propeller device 100 Vortex 103 Sign light 104 Rope 105 Submersible float 106 Rope 107 Support flame

Claims (2)

[Claims] 1. An air draw prevention device for a jellyfish elimination water flow generating device, wherein a vortex contact body formed by connecting a large number of floating bodies in a daisy chain is provided on a water surface almost immediately above the water flow generating device.
An air draw prevention device, which is provided substantially parallel to the water flow generation device. 2. The air draw prevention device according to claim 1, wherein a vortex contact cloth is suspended from the floating body.