JPS6359027B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a device for extracting energy from waves.

Some examples of flotation devices adapted to extract energy from waves are the device invented by Yoshio Masuda and described in British Patent Specification No. 1014196, and the device described in Japanese Application No. 97699/77. These devices are configured to extract energy from waves by vibration of a column of liquid arranged to perform useful work.

Other examples of devices for extracting energy from waves are summarized in British Patent Specification No. 1482085 Salter
“Duck” and the subject matter of British Patent Specification No. 1448204. Christopher, Member of the British Academy
This is a "raft" device proposed by Cockerell.

One of the difficulties encountered in creating devices for extracting energy from waves is achieving significant energy extraction efficiency. The invention therefore relates to improving the energy extraction efficiency of such devices for applications.

According to the invention, a method for manufacturing a device for extracting energy from waves which, in use, floats with a degree of freedom of movement in a vertical plane aligned with the direction of propagation of the waves, comprising: (i) being below the surface of the liquid in use; (ii) test the model of the device under representative desired operating conditions to determine the transmitted wave heights, respectively, relative to the incident wave heights; (iii) change the center of gravity position of the model device and the radius of rotation around this center of gravity as a whole, and (iv) determine the ratio of the incident wave height to the transmitted wave height and the incident wave height to the reflected wave height. Repeat steps (ii) and (iii) until finding the value of the center of gravity position and radius of rotation for which the ratio of wave height is the minimum or is close to the minimum, and (v) minimize these ratios. Alternatively, the apparatus is characterized in that the apparatus is created by similarly enlarging the model found to be close to the minimum. Thus, in a device for extracting energy from waves according to this method, the device can move in a vertical plane aligned with the propagation direction of the waves approaching the device, and the device can move in response to said waves. The movement of the device in response to the waves is
The shape of the parts of the device below the liquid surface, the location of the center of gravity, and the value of the radius of gyration around the center of gravity in said vertical plane are such that the transmission and/or reflection of waves by the device itself is suppressed to a significant extent. We are prepared.

Preferably, the device manufactured according to the invention is optimized with respect to energy extraction to operate within a particular range of wave wavelengths.

Also, in devices made in accordance with the present invention, the air in the device is arranged to perform useful work, such as driving air through an air turbine or through an orifice adapted to drive a generator. Vibration of the liquid column makes it possible to extract energy from the waves, which in the latter case consumes energy when passing through the orifice, thereby allowing the device to act as a breakwater.

Additionally, a device made in accordance with the invention may be constructed of at least two elements and used such that relative movement between said elements in response to waves allows the device to extract energy from waves. In this case, one of the elements is the gist of British Patent Specification No. 1482085.
It would be nice if it consisted of Salter “Duck”.

As a variant, the two elements can also consist of a raft-shaped device.

In a vertical plane aligned with the direction of the approaching waves,
A stationary floating device with a symmetrical underwater geometry has a theoretical power absorption rate of about 50% of the energy of the approaching waves, with the remaining wave energy being transmitted by the device itself or reflected. Dissipated equally distributed between waves.

A device with a particular underwater geometry and weight distribution due to the wave-to-wave energy extraction manufacturing method of the present invention may be configured to be able to carry out special combinations of translational and/or rotational movements in the vertical plane as described above. , so that when extracting energy from the waves, the waves generated by the translational, rotational movements, ie the waves generated by the device, cancel each other out so as to suppress the transmission and reflection of waves by the device itself.

There are a number of underwater geometries that can be used for the proper location of the center of gravity and the value of the radius of gyration around the center of gravity in the manufacture of such floating devices, and once the location of the center of gravity and the value of the radius of gyration are determined, energy can be extracted from the waves. In doing so, this center of gravity location and radius of gyration values can be applied proportionally to a particular device to optimize device performance. For this purpose, a suitable underwater geometry and the corresponding location of the center of gravity and value of the radius of gyration can be determined by use of the model in the wave tank.

The invention will now be described by way of example with reference to the accompanying drawings.

Referring to FIG. 1, the illustrated device has a tank 10 of rectangular shape in plan and partially filled with water, which tank is connected at one end (by means of a device not shown). ) Swinging tank 1
A wave generator 12 is provided in the form of a cam-shaped vane arranged to transmit waves along the 0. An expanded metal wave absorber 13 is placed at the other end of the tank 10 to prevent waves from bouncing back. Model 14 of floating device to be tested
A wave height gauge 15 is placed in the tank 10 and detects waves transmitted by the model 14.
It is placed near the wave absorbing device 13. Two wave height gauges 16 and 17 separated by a distance equal to a quarter of the wavelength are used to detect the waves produced by the wave generator 12 and the waves reflected by the model 14. It is located between the device 12 and the model 14.

The model 14 consists of a number of vertically arranged wooden blocks 19 each having four openings 20 and connected to each other. The upper part of the model 14 is constituted by a molded wooden block 21 connected to the top of the block 19 and having a downwardly extending hollow part 22 with a rounded end.
This block 21 constitutes the upper part of a chamber 23 in which the air pocket is trapped by the water column. The base of the chamber 23 is constituted by horizontally extending blocks 19, the outermost of which has rounded ends.

Two containers 25 are connected to each other and attached to a molded block 21, which
An aluminum sheet 26 is connected to the container 25.
and the lowest part of the vertically disposed block 19 to form a cavity 27. The orifice 28 of the bridge portion 29 of the molded block 21 is located in the chamber 23.
This orifice 28 communicates with the pressure gauge 3.
0 is connected to chamber 23 on the opposite side.

Referring now to Figure 1a , glass panel 3
1 are placed on each side of the model 14,
These panels do not need to be in close contact with the model 14, and water may enter the cavity 27. Metal bar weights 32 (only one shown) are placed in some of the openings 20 to provide the necessary weight distribution around the model. Referring again to FIG. 1, the water in the container 25 and the hollow portion 22 of the molded block 21 supplements the weight 32 in achieving the required weight distribution, from which the location of the center of gravity and The value of the radius of gyration around the center of gravity can be determined.

To test model 14, wave generator 12
The model 14 is actuated to move toward the model 14 and transmit the incident wave to it. The height of these approaching waves is indicated by an incident wave height gauge 16. The water in chamber 23 is shaken by the influence of these waves incident on model 14 and the energy extracted from the incident waves is determined by the pressure indicated by pressure gauge 30.

The height of all waves transmitted by the model 14 is determined by a transmitted wave height gauge 15;
Similarly, the heights of all waves bounced by model 14 are determined by comparing the wave heights indicated by wave height gauges 16 and 17, respectively.

The shape of model 14 and its weight distribution can then be changed by removing, adding or redistributing blocks 19, weights 32 and containers 25, and by adjusting the amount of water in containers 25 and hollow portions 22. By changing the shape of the aluminum sheet 26, if necessary, by changing the shape of the aluminum sheet 26. This reshaped model 14 is then retested in the manner described above, and several reshaped models 14 in succession are retested.
The reshaped model 14 that gives the best results, i.e. the lowest transmitted and reflected wave heights, is selected as the one closest to the optimum conditions, and the size, weight distribution, center of gravity and rotation of this reshaped model are selected. The radii are calculated so that they can be applied proportionately to suit the particular application.

When a model 14 similar to that shown in Figures 1 and 1a is tested as described above, the optimal size (proportions) of the underwater shape, the location of the center of gravity and the radius of gyration around the center of gravity are determined. The values are determined as shown in FIGS. 2 and 3.

In FIG. 2, the model 14 shown in a schematic cross section
is annotated with respect to the interrelationship of the dimensions of the underwater geometry, the location of the center of gravity of the model 14, the radius of rotation of the model 14 around this center of gravity, the average height of the water in the chamber, the water line and the wavelength of the incident wave. There is.

The dimension 'L' in Figure 2 is related to the wavelength of the incident wave;
In applications where L' is approximately equal to 1/10 of the wavelength of the incident wave, it is desirable to utilize the dimensions of FIGS. 2 and 3. The wavelength of the incident wave of the model 14 in the tank 10 of FIG. It can be changed by changing .

The model 14 in FIG. 2 has approximately the energy of the incident wave.
75% is converted into useful work, approximately 5% is converted into transmitted waves, approximately 5% is converted into reflected waves, and the remaining energy is
It was found that 15% was consumed as losses during model operation. Freeboard above the waterline is not important except in relation to the location of the center of gravity and the value of the turning radius. It will be appreciated that in practical devices, a value on the order of 5% of the transmitted and reflected waves means that the losses associated with such devices are significantly reduced.

The model 14 shown in FIG. 3 is similar to the model 14 of FIG. 2 and is described in a similar manner. However, although the displacement of model 14 of FIG. 3 is much lower than model 14 of FIG. 2, it has little effect on the efficiency of the model in extracting energy from waves.

The dimensional proportions of the models shown in FIGS. 2 and 3 can be adapted to equipment for specific applications.

The model 14 in Figure 1 and the configuration shown in Figures 2 and 3 relate to devices that rely on vibrations in the water column to pressurize a gas, such as air, above the water column, and to direct this gas through an orifice into a turbine, such as a turbine. By discharging into a mechanical device, or by sizing the orifice 28 so that the energy is lost in passage through the orifice and the device acts as a bulwark, the gas is discharged through the orifice. The energy is extracted from the incident wave by

The orifice sizes shown in FIGS. 2 and 3 relate to orifices used in such breakwater devices. An example of a device for extracting energy from waves using vibrations in the water column is given in the aforementioned patent specification No.
No. 1104196 and Japanese Application No. 97699/77. A device that operates with the use of a vibrating water column to extract energy from waves is shown in FIG.

The device shown in FIG. 4 is of a buoyant construction, in a vertical plane aligned with the direction of wave propagation of the liquid (e.g. seawater) on which it floats.
It has the size (proportion) and weight distribution shown in FIG. The device includes a front wall 35, a molded rear wall 3
6, a lower end wall 37, and an upper portion 38 sealing the chamber 23 between the front wall 35 and the rear wall 36.
A port 39 between the bottom of the front wall 35 and the lower end wall 37 allows liquid to flow into and out of the chamber 23 in wave motion on the liquid surface.

The rectifying valve structure is provided by a check valve air inlet 40 to prevent return into the chamber 23 and a check valve air outlet 41 to prevent return from the chamber 23, the air inlet 40 and the air outlet 41 , connected to an air duct 42 with a check valve air inlet 43 from the atmosphere and a check valve air outlet 44 to the atmosphere. An air turbine 45 is disposed in the air duct 42 and is connected to the generator 4 so that as air flows through the air duct 42 it can drive a generator 46.
6.

The device has an elongated shape in the direction parallel to the waves as shown in FIG.
and constitutes a plurality of chambers 23, each connected to an air turbine 45 (not shown) and a generator 46 (not shown).

In operation of the apparatus of FIGS. 4 and 5, the vibration of the liquid in the chamber 23 in wave motion causes the air inlet 4
Air is drawn into chamber 23 through air inlet 3 and air outlet 41 and then expelled from chamber 23 through air inlet 40 and air outlet 44. The direction of the air flow in the air duct 42 is unidirectional, as is clear from the arrows indicating the air flow, so the air turbine 45 controls both the upward and downward movement of the liquid in the chamber 23. Driven for a while.

A device similar in most respects to the device shown in FIGS. 4 and 5, but having the dimensions (proportions) and weight distribution of FIG. 3, is shown in FIG. The device of FIG. 6 is similar to the device of FIG. 4, although it has a rear wall 36a with parallel side walls instead of the triangularly formed rear wall of the device shown in FIG. operates in the same manner as described;
Extract energy from waves.

Although the check valves for air inlets 43 and 40 and air outlets 41 and 44 are shown in FIGS. 4 and 6 as having a single closure, multiple closures in parallel relationship may be used. (not shown) may be used depending on the dimensions of the air inlet 40 or 43 or the air outlet 41 or 44. Although the energy extraction device produced by the method of the present invention has been described in the context of a device that extracts energy from an incident wave using vibrations in a water column, the present invention also relates to a device that extracts energy from an incident wave using vibrations in a water column. Other devices used in the Salter “Duck”, for example
Apparatus and Summary of British Patent Specification No. 1448204
It may also be combined with a device that derives power by moving one element relative to another, such as a Cockerell raft device.

Referring now to Figures 7 and 7a , several
A Salter "Duck" 50 is mounted on a rod 51 supported by a floating carrier device 52. The carrier device 52 has a number of partitions 53 arranged in parallel along the carrier device 52 to support the rods 51. In the method according to the invention described in connection with the installation of FIG.
By suitably testing the configuration and radius of rotation of the combination device with the “Duck” 50, the configuration, location of the center of gravity, and radius of rotation about the center of gravity values for the carrier device 52 and the Salter “Duck” 50 are determined. Salter minimizes the transmitted and reflected waves from the combination device and therefore
The swinging of the "Duck" 50 is determined to maximize the energy that can be extracted from the incident wave. A relatively short carrier device 52 may be used with only a few or just one Salter "Duck" 50, and the Salter "Duck" 50 may be
Although the Salter “Duck” 50 exhibits a translational motion with the carrier device 52 in response to the incident wave, the shape, center of gravity position and rotation of the carrier device 52 in combination with the Salter “Duck” 50 is controlled by the present invention. It will be appreciated that the value of the radius is chosen so as to still have a relatively high wave energy extraction efficiency. For details of the Salter “Duck” 50, reference is made to British Patent Specification No. 1482085.

Referring now to Figures 8, 8a and 8b , the principle is roughly similar to Cockerell's raft,
The essential features of a raft-type device for extracting energy from an incident wave are shown, each connected to a pivot rod 57 across a slot 59 in the beveled top of the carrier raft 58. A float 55 is provided which is pivotally connected by two A-shaped frames 56. The A-frames 56 each have an upright lug 60 and form a fixed part for a pivot rod 61 to which the fork end 62 of a piston rod 63 of a hydraulic piston pump 64 is pivotally connected. The cylinder member 65 of the pump 64 extends across the slot 69 in the top surface of the carrier raft 58.
It is pivotally connected to a pivot rod 67 located at 8.

In operation, relative motion between float 55 and carrier raft 58 in response to an incident wave is used to perform mechanical work by pumping hydraulic fluid in pump 64 through a hydraulic circuit (not shown). Let's do it.

As described in connection with the Salter “Duck,” the geometry, center of gravity location, and radius of gyration around the center of gravity values are selected to minimize transmitted and reflected waves from the apparatus of Figures 8-8b, and determined to maximize the energy extracted from the waves. An elongated device having a number of floats 5 connected in parallel relation to a single carrier raft 58 may be used in a manner similar to that described in connection with the Salter "Duck" in Figure 7a . .

Although the apparatus of FIGS. 2-8 is shown as a solid structure, suitable air space is provided to provide buoyancy and to assist in arranging the required location of the center of gravity and the value of the radius of rotation around the center of gravity. It is better to have a body.

Wave height gauge 1 used in the equipment shown in Figure 1
5, 16 and 17 are gauges conventionally used to determine wave height.

In the foregoing description of the invention, it is understood that the translational movement of the device relates to a vertical movement and/or a horizontal movement in a vertical plane aligned with the direction of the incoming waves. Such movements are also known as ridges and undulations, respectively, while rotational movements in this vertical plane are known as pitches. Movements intersecting this plane may also occur simultaneously with the aforementioned movements in said plane. If the device is relatively long in the direction perpendicular to this vertical plane compared to the length of the device between the front and rear parts in the vertical plane, the movement of the device in response to the waves will be substantially less in said vertical plane. becomes two-dimensional.

Furthermore, the method of manufacturing a device for extracting energy from waves according to the invention comprises a device for extracting energy from waves on a liquid which makes the device float, the device comprising: A device is manufactured which is arranged to respond to said waves with a combination of ridges, undulations and pitches which suppress reflections to a significant extent.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross - sectional view of equipment for a test model of a floating device used in the manufacturing method of a device for extracting energy from waves ;
an enlarged cross-sectional view along the line a ; FIG. 2 is a schematic cross-sectional view of the contour of the floating device with optimal parameters;
3 is a schematic cross-sectional view of the profile of another floating device with optimal parameters; FIG. 4 shows the parameters of the device of FIG. 2 according to the method of manufacturing the device for extracting energy from waves according to the invention; 5 is a cross-sectional view taken along the line - of FIG. 4, and FIG. 6 is a schematic cross-sectional view of the device according to the present invention for extracting energy from waves. a schematic cross-sectional view of the device with the parameters of the device;
FIG. 7 is a schematic cross-sectional view of a floating device used in the method of manufacturing a device for extracting energy from waves according to the present invention, which is different from that shown in FIGS. 2 to 6; FIG . 7 viewed from the direction of arrow A, and FIG. 8 a floating device used in a method for manufacturing a device for extracting energy from waves according to the present invention, which is further different from that shown in FIGS. 2 to 6. , 8th a.
The figure is a cross-sectional view taken along line a-a in FIG. 8, and FIG. 8b is a fragmentary view of FIG. 8 viewed from the direction of arrow X. 12... wave generator, 14... model, 23...
...chamber, 27...cavity, 28...orifice, 30
……Pressure gauge.

Claims (1)

[Scope of Claims] 1. A method for manufacturing a device for extracting energy from waves that, when in use, floats with a degree of freedom to move in a vertical plane aligned with the direction of wave propagation, comprising: (ii) test the model of the device under conditions of representative desired operating conditions to determine the transmitted wave height relative to the incident wave height; (iii) change the center of gravity position of the model and the radius of rotation around this center of gravity as a whole; and (iv) determine the ratio of the incident wave height to the transmitted wave height and the incident wave height to the reflected wave height. Repeat steps (ii) and (iii) until finding the value of the center of gravity position and radius of rotation in which the ratio of wave height is the minimum or is close to the minimum, and (v) minimize these ratios. Alternatively, a method for manufacturing a device for extracting energy from waves, characterized in that the device is created by similarly expanding the model found to be close to the minimum.