WO2011062401A2

WO2011062401A2 - Wave power conversion device

Info

Publication number: WO2011062401A2
Application number: PCT/KR2010/008049
Authority: WO
Inventors: 김종철
Original assignee: Kim Jongchul
Priority date: 2009-11-18
Filing date: 2010-11-15
Publication date: 2011-05-26
Also published as: KR101076080B1; WO2011062401A3; KR20110054919A

Abstract

Waves can only be found in the sea but are nevertheless the most attractive of all forms of renewable energy (sun, wind, hydro, tide, wave and geothermal). However, vibration characteristics have not been well understood hitherto and this technology improves productivity and survivability and paves the way to the unhampered use of wave power by means of a slight modification to the shortcomings of the prior art in terms of energy production using wave power.

Description

Wave power converter

The present invention relates to a power converter for converting the up and down oscillation kinetic energy of a liquid into a flow of a pressurized fluid pressurized gas or liquid, or by using a linear generator or a rotary generator.

In the case of wind power generation with a cost of 1/6 to 1/8 compared with photovoltaic power generation, if the wind speed is 5-6 m / s or more, it is economical. When the wind speed is 7m / s, the energy density is 206 W / ㎡, while the wave in the area where the waves are a little more than 50% of the waves dug year-round is 1.5 ~ 2.0m or less, and when the wave height is 2m, it is 5,000 W / ㎡. .

The higher the energy density, the more economical the waves are an attractive energy source, but the wave power generation is not widely spread because of the problems with the prior art.

The principle of wave power converter is that when a wave is forcedly vibrated against the power converter, vibration occurs in the power converter, and the power converter converts the vibration energy into the form of energy we need (electricity, pressurized fluid). , Mechanical kinetic energy, etc.).

In general, the vibration in the machine is troublesome, shorten the life of the machine and cause failure, especially avoid the resonance phenomenon extremely. However, in the wave power converter, the larger the generated vibration is, the more advantageous the resonance is.

A buoyancy force is a force acting in a direction opposite to gravity by the weight of the (peripheral) fluid, which is partially or entirely buoyant means submerged in the surrounding fluid.

Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object.

--- Archimedes of Syracuse

Therefore, the buoyancy increases as the buoyancy means increases. However, the vibration energy does not increase because the buoyancy means increases. In the case of disk cylindrical float, when the wave length is L, the maximum vibration energy is obtained when the diameter D of the disk is D = L / 2π = 0.159L.

However, the wave's wavelength often changes.

In addition, since the wave direction is not constant, most wave power converters are difficult to enlarge due to the adoption of circular buoyancy means.

In the following vibration equation, the natural frequency is

If the buoyancy means is cylinder D, the natural frequency is

to be. It is a circular cylinder that is blocked at the top and bottom and partly exposed on the surface of the water. It is a stable system because the spring always restrains the movement of the power converter. If we want to induce resonance in this stable system, the natural frequency of the wave power converter is the frequency of the wave.

Should be equal to

Therefore, wave power converters generally use air springs, magnetic springs, etc. to change the elastic modulus, or to subtract seawater in buoyancy means to change mass. However, these methods have little change amount and are slow to change, so they cannot cope with the changing speed of the wave. The device is complicated and the energy production rate is low compared to the increase of initial and maintenance costs.

Another reason for the slow spread of wave power converters is that the wave whims are too severe.

Usually, more than 50% of the sea is dug 1.5 ~ 2.0m year-round, but sometimes there is only 20m wave. It is obvious that equipment with 100 times robust energy density (which will be 100 times more expensive), which is proportional to the square of the crest, is uneconomical for producing energy, typically at one hundredth of its performance.

It is even more damaging if you build equipment that is suitable for normal operating conditions (less than 2m in height), and only a few years later, if it is economically viable.

In the present invention, various problems of the prior art, namely, the buoyancy change, the natural frequency change, the wave vibration absorption rate, etc. of the wave power converter which are too late or too weak with respect to the speed at which the wave changes, are simply applied to some equipment elements. I will change to solve it.

Wave power converter of the present invention is composed of at least one buoyancy means, power converter, support means, and connecting means connecting them.

The supporting means can be laid on the bottom of the sea to lay the foundation, or in places where it is difficult to construct, the weight or anchor can be dropped from the sea to locate the buoyancy means and supporting means while using relatively light weights. A drag plate can be added to induce a large relative movement between them. The drag plate may be made of rigid material, but it is preferable to use a cloth such as a parachute to reduce costs.

Fig. 1 is a wave power converter in which a part of the buoyancy means (3) is exposed on the surface of the support means consisting of the anchor (1-1) and the drag plate ( 1-2) , and the power converter is located in the buoyancy means. Suitable for the same small system.

Figure 2 is a small isometric system as shown in Figure 1, but the concept of applying the concept of the present invention, which is almost the same as the components of the prior art, but dynamically unstable system even with a slight change in the use of the attachment position or technology elements. As a result, it is shown to cause resonance for almost all waves.

The power converter converts up and down reciprocating motion, that is, vibration into energy-friendly form, and consists of a cylinder, a one-way check valve, and a piston to pressurize the surrounding fluid, that is, the seawater reservoir on the high land. It may be stored and hydro-powered if necessary, or electricity may be directly produced by a linear generator driven by a direct drive or by a rotary generator geared with hung in a hydro turbine driven by pressurized seawater. A simpler flexible hose and hose pump with a one-way check valve is also available to create pressurized fluid.

In order to increase energy productivity, the buoyancy means must first absorb as much of the vibrational energy of the waves as possible.

The buoyancy force should be increased in proportion to the volume and the buoyancy means in the direction of wave propagation should be one length (wavelength of wave) divided by (2π) for the vibration energy, but there is no restriction on the width.

Therefore, it is possible to increase the size and to change the length of the buoyancy means in the wave propagation direction if a wave is aimed for a wider range of wavelengths.

The canopy material uses a flexible fiber or tent cloth and can be adjusted in length by adjusting the pressure of the working fluid to air tubes, hydraulic cylinders, air bellows and the like to adjust the length. Alternatively, telescopic arms driven by electric servomotors are also available.

The posture control means is provided with the buoyancy means so that the width of the buoyancy means is always perpendicular to the direction of wave propagation. Posture control means use propellers, screws, compressed air jets or propellers used in ships or submersibles. Observation of the period, amplitude, wavelength, etc. of the wave uses the measured value of the wave at close range as not affected by the wave power converter.

To reduce system components, passives are preferred over active posture control with propellers. In order for the buoyancy means to have the width of the buoyancy means perpendicular to the direction of wave propagation, the shape of the buoyancy means has a concave shape with respect to the wave advancing direction.

After the buoyancy means receives the vibrational energy of the wave as much as possible, in order to produce a large amount of energy of the desired form, the resonance must be made at a wide range of wave frequencies to be a wave power converter.

As mentioned earlier, changing the mass and spring coefficient of a wave power converter is limited and expensive.

Therefore, make the spring mass system an unstable, always diverging system.

The following vibration equation is the case where all buoyancy means are submerged in a general spring system (prior art). Here, the buoyancy means is open at the bottom of the rigid body so that the water occupies freely and changes the volume occupied by the air, or the buoyancy means body is soft even though it is sealed like an air bag. The volume can change, and the whole buoyancy means is submerged in seawater.

At the equilibrium point, the position of the buoyancy means will be maintained, but if it rises due to slight fluctuations, the water pressure will be lowered and the volume will increase to increase the buoyancy force, which creates an ascending force, which rises to the hydraulic pressure drop and continues to rise. Descending from the equilibrium point increases the water pressure, which leads to a decrease in volume and an increase in water pressure, which in turn leads to a continuous decrease in volume.

In other words, it is an unstable system due to the continuous divergence within the wave cycle.

Here, the method of making the constant for displacement x completely negative causes the prior art spring to be eliminated. When a completely unstable system always diverges, resonance does not occur even if the natural frequency is not set to the wave frequency. However, due to the characteristics of the resonance, the amplitude of the generated vibration is larger than the original wave amplitude, so there is a fear of moving out of the operating range of the wave power converter, and the resonance may be shifted due to the delay in operation. Therefore, a spring or elastic stopper or latch is placed at the top dead center and bottom dead center of the power converter as a means of controlling it.

Alternatively, the elastic bumper and the spring may be attached to the driver of the piston or the linear generator, but unlike the prior art, the motion of the motion is constrained, i.e., the motion energy is converted into elastic energy, and then restrained only near the dead points. Convert it to energy and return it to the exerciser.

The phase control is possible by adjusting the distance between the dead points according to the change of the wave.

The characteristic of the resonance is that the amplitude of vibration generated is much larger than the original vibration amplitude, and the phase difference between the two vibrations is 0 ° or 180 °, and the phase difference can always be 0 ° or 180 ° by adjusting the distance between the two dead points of the power converter. . Thus, resonance occurs for waves of almost all frequencies.

In order to increase the viability of machinery in the sea, it is preferable to keep only the buoyancy means near the water surface and the rest near the bottom of the sea. For waves in the range that the buoyancy means can handle, operate near the surface of the water, but for waves above the limit, evacuate the buoyancy means near the bottom of the sea.

Therefore, the connecting means is provided with a length adjusting means, such as a squeeze or winch to adjust the length.

Survival, the biggest problem of structures in the sea, and the simplicity of the components, the resonance is solved for the waves in almost all frequency domains. Most of them are often destroyed by extreme weather during long-term construction in a distant sea where material transportation and construction are difficult, but the present invention has been prepared on land so that it can be installed in a distant sea. And most of the components can be standardized by module to be mass-produced and large in size.

Figure 1: Compact System for Slip Tables Using the Prior Art

Fig. 2: A concept diagram of a small-segment system using some of the concepts of the present invention, which is similar to the prior art elements, but shows that it can cause resonance for almost all frequencies.

Figure 3: Actual implementation of a large energy generation system applying the advantages of the present invention

Figure 4: The buoyancy means of the wave power converter can be made larger, instead of the active posture control means. Conceptual drawing of the passive posture buoyancy means structure which is passive and always keeps the width of buoyancy means perpendicular to the direction of wave travel

Figure 3 shows a large energy production system that takes advantage of the present invention.

The power converter consists of a linear generator, in which the springs (6) are attached to a stopper (8) which is adjustable in length or position in order to adjust the top dead center and the bottom dead center.

The buoyancy means (3) consists of an air bag and has a discharge port (9) for releasing the air of the buoyancy means (3) in order to speed up the descending speed of the extreme wave evacuation of the buoyancy means.

After the wave is calm, the air supply hose 10 is provided to lift the buoyancy means again. The air tank used for scuba diving is filled from 200 atm to 250 atm. The use of such compressed air tanks is inexpensive.

And a bobbin (11) for adjusting the distance between the buoyancy means (3) and the armature (5) consisting of an electromagnet or a permanent magnet, which is a mover of the power converter.

Figure 4 is a large buoyancy means to adjust the wave traveling direction length of the buoyancy means, and always canoe blood 15 in that the air pocket to be of buoyancy means to the wave traveling direction the width lies in a vertical polyurethane cloth or waterproof This is a conceptual view of the sea from the top, using nylon or deckon. Framed with two composite or aluminum struts (12) to maintain rigidity in the width direction, and adjust the pressure of the working fluid as a spring or bobbin band (13) and an air or hydraulic cylinder to adjust their spacing There is an air cylinder or air bellows 14 for adjusting the length of the buoyancy means. And a material capable of maintaining rigidity, such as plastic or metal, composite, or plastic, such that the buoyancy means has a convex width in the direction of wave propagation so that the buoyancy means is always perpendicular to the direction of wave travel. The vane 16 or oar, quarter rudder was attached.

Claims

In producing the flow of pressurized fluid from the vibrating motion of liquid or other forms of kinetic energy such as mechanical kinetic energy, electricity,

One or more buoyancy means: The buoyancy means is a material such as iron, aluminum, composite material, nylon, macron, aramid fibers, buoyancy by holding air in the form of a round or square cylinder tube or sphere, ellipse sphere to maintain the volume Receiving apparatus;

Power converter: The power converter may include a rotary generator or a linear generator that generates electricity when the exerciser in the power converter is driven, or a power converter such as a pneumatic pump, a hydraulic pump, or a hose pump that generates a flow of pressurized air or a pressurized water flow;

Supporting means: The supporting means is a foundation or a pile anchored on the ground or wave power converters such as anchors, weights, ballasts, drag plates do not drift to other places, and the power converter is supported so that the vibration movement is greatly generated by the waves Apparatus for making;

Connection means: a connection mechanism consisting of a combination of the pull line, the bridle, the strut, the frame, the beam connecting the buoyancy means, the power converter, the support means;

Wave power converter
The method according to claim 1,

Air tubes, pneumatic cylinders, hydraulic cylinders, electro-driven telescopic arms for adjusting the length of the buoyancy means parallel to the direction of wave propagation in one or more buoyancy means.

Wave power converter further comprising a length adjusting means
The method according to claim 1,

At least one buoyancy means further comprises a posture adjusting means, which can adjust the posture of the buoyancy means, such as a bow thruster, propeller, screw, compressed air injection device so that the width of the buoyancy means perpendicular to the direction of travel of the wave. Wave power inverter
The method according to claim 1,

The concave shape is attached to at least one buoyancy means by attaching an additive such as a vane or aer so that the buoyancy means is generally concave in the direction of the wave so that the width of the buoyancy means is perpendicular to the direction of travel of the wave. Or the buoyancy means itself has a concave shape, the wave power converter further comprises a buoyancy means having a concave shape of the buoyancy means width when the shape of the buoyancy means in the wave progress direction.
The method according to claim 1,

The power converter is a means for adjusting the length of the reciprocating section of the exerciser reciprocating in conjunction with the buoyancy means such as the exerciser and the piston of the power converter, the elastic stopper with adjustable length, the elastic latch with adjustable position, the elastic bumper Wave power converter including one or more movement section control means of the power converter or buoyancy means
In the connecting means of claim 1,

To the buoyancy means and the movement of the power converter, a piston, such as a traction line, a bridle line to interlock with the piston, the winch, the bobbin for adjusting the length of the connecting means, a bobbin, the length adjustment means such as a slewing force Inverter
In the buoyancy means of claim 1.

When the buoyancy means descends, the buoyancy decreases, and when the buoyancy means rises, the buoyancy increases, that is, a wave power converter further comprising buoyancy means having unstable motion characteristics
To the power converter of claim 1,

The mover of the power converter or the mover linked to the buoyancy means such as the piston can adjust the position of the top dead center and the bottom dead center such as the elastic bumper or stopper and the latch only near the top dead center and the bottom dead center or the top dead center and the bottom dead center. Wave power converter further comprising a power converter having a feature constrained by the means present