NO20093313A1

NO20093313A1 - Method for conversion of wave power

Info

Publication number: NO20093313A1
Application number: NO20093313A
Authority: NO
Inventors: Arvid Nesheim
Original assignee: Arvid Nesheim
Priority date: 2009-11-10
Filing date: 2009-11-10
Publication date: 2011-05-02
Also published as: NO330490B1

Description

Foreliggende oppfinnelse augar en metode far omfamning av bølgekraft til energitilstsndier egnet for utnytting. Metoden er relatert ril bclgekraftomfortnere som hai en flottar (1) som svinger vertikalt, horisontalt eller dreier om horisontale akser under påvirkning av sjøbølger og hvor uttak av energi skjer ved demping av bevegelser mellom flottaren (1) og et eller flere mothold, som for eksempel kan være flytende sjøanker. The present invention provides a method for embracing wave power into energy states suitable for utilization. The method is related to conventional power converters such as a float (1) that oscillates vertically, horizontally or rotates about horizontal axes under the influence of sea waves and where energy is extracted by dampening movements between the float (1) and one or more counterweights, such as for example can be a floating sea anchor.

Fra tidligere teori innen fagområdet er det kjent følgene krav for at energiuttaket fra nevnte type bølgekraftomfbnnere skal bli størst mulig: egenfrekvensen til flottøren skal kunne være lik frekvensen til innkommende bølger From previous theory in the field, the following requirements are known for the energy output from the aforementioned type of wave power converters to be as large as possible: the natural frequency of the float must be equal to the frequency of incoming waves

slik at det oppstår resonans med følgende stor svingeamplitude so that resonance occurs with the following large oscillation amplitude

- demping av relative bevegelser mellom flottør og mothold må skje med riktig størrelse på dempingskraften og til riktig tidspunkt i forhold til bølgebevegelsene - damping of relative movements between the float and counter-hold must be done with the right size of the damping force and at the right time in relation to the wave movements

Overnevnte krav bar imidlertid vært vanskelig å oppfylle ettersom frekvensen til bølgene vil variere slik at egenfrekvensen til flottøren automatisk må kanne endres, samt at bølgebevegelsene ikke følger en jevn sinuskinve men kan være irregulære slik at det stilles store krav til reguleringssystemet som skal styre denæingskraften. However, the above-mentioned requirements would have been difficult to fulfill as the frequency of the waves will vary so that the natural frequency of the float must be able to change automatically, and that the wave movements do not follow a smooth sine wave but can be irregular so that great demands are placed on the regulation system that will control the denation force.

Foreliggende opptfinnelse er en praktisk metode for å oppnå stor svingeamplitude og for å dempe relative bevegelser mellom flotter og mothold. Metoden er beskrevet med hensyn pa en bølgekralfomfbrmer som har en ringformet flottør (1) montert rundt en flyende søyle (2) med to eller flere flytende sjøanker (3, 4) seriekoblet til nederste ende av søylen. The present invention is a practical method for achieving a large swing amplitude and for dampening relative movements between floats and counter-holds. The method is described with respect to a wave kraal fomer which has an annular float (1) mounted around a floating column (2) with two or more floating sea anchors (3, 4) connected in series to the lower end of the column.

Flottøren (1) er dreibart koblet til søylen (2) hvor det inngår en fjærforbindelse (Kl) og en bevegelsesdemper (Dl) mellom flottaren og søylen. Hvert sjøanker (3, 4) har et kammer fylt med sjøvann som i tillegg til hydrodynamisk tiUeggsmasse utenfor kammeret svinger med sjøankeret. Sjøankerene er seriekoblet til nedre del av søylen (2) med fjærforbindelser (K2, K3) og bevegelsesdempere (D2, D3). Fjærførbmdelsene kan bestå av forskjellige typer fjærer som stålfjærer, hift- eller gassfjærer eller kombinasjoner av disse. The float (1) is rotatably connected to the column (2) where a spring connection (Kl) and a movement damper (Dl) are included between the float and the column. Each sea anchor (3, 4) has a chamber filled with seawater which, in addition to hydrodynamic sediment outside the chamber, oscillates with the sea anchor. The sea anchors are connected in series to the lower part of the column (2) with spring connections (K2, K3) and movement dampers (D2, D3). The spring means can consist of different types of springs such as steel springs, lift or gas springs or combinations of these.

Bevegelsesdemperene er typisk pneumatiske eller hydrauliske sylindere som pumper luft eller vann til en turbin (5) som kan være plassert pa selve bølgekrafiomformeren eller på land. Turbinen (5) er koblet til et eller flere svinghjul (6, 7) som igjen er koblet til roterende utstyr som utnytter energien som for eks. en elektrisk generator. Mellom turbinen og mellom svinghjulene er det fjærkobhnger (K5, K6) og det kan også inngå gir. Hvert svinghjul er fri til å rotere med større hastighet enn turbinen eller det svinghjulet som yter drivkraft. The motion dampers are typically pneumatic or hydraulic cylinders that pump air or water to a turbine (5) which can be located on the wave energy converter itself or on land. The turbine (5) is connected to one or more flywheels (6, 7) which are in turn connected to rotating equipment that utilizes the energy, such as an electric generator. Between the turbine and between the flywheels there are spring couplings (K5, K6) and gears can also be included. Each flywheel is free to rotate at a greater speed than the turbine or the flywheel providing the driving force.

Et karakteristisk trekk ved foreliggende oppfinnelse er at motholdet ril flottøren (1) omfatter en rekke vertikalt seriekoblede sjøanker (3,4), som er innrettet slik at hvert sjøanker svinger med en egenfrekvens som induserer resonans i minst et av de øvrige sjøankerene og flottaren. Dette oppnås ved at hvert enkelt sjøanker har en dynamisk masse og fjærforbindelser (K2, K3) som er tilpasset slik at sjøankeret har en bestemt egenfrekvens i forhold til overliggende eller underliggende sjøanker. Fordelen som oppnås er at høye svmgeamplihider oppnås serv om frekvensen til sjøbølgene er forskjellige fra egenfrekvensen til flottøren eller om bølgene er irregulære. A characteristic feature of the present invention is that the resistance to the float (1) comprises a number of vertically series-connected sea anchors (3,4), which are arranged so that each sea anchor oscillates with a natural frequency that induces resonance in at least one of the other sea anchors and the float. This is achieved by each individual sea anchor having a dynamic mass and spring connections (K2, K3) which are adapted so that the sea anchor has a specific natural frequency in relation to overlying or underlying sea anchors. The advantage achieved is that high waveform amplitudes are obtained even if the frequency of the sea waves is different from the natural frequency of the float or if the waves are irregular.

Et annet karakteristisk trekk vedl foreliggende oppfinnelse er at uttak av energi skjer ved at denmeikreftene mellom flottøren (1) og motholdene (2, 3, 4) absorberes av en rekke seriekoblede svinghjul (6,7) som er tilpasset demperkreftene. Another characteristic feature of the present invention is that energy is extracted by the damping forces between the float (1) and the counter-holds (2, 3, 4) being absorbed by a number of series-connected flywheels (6,7) which are adapted to the damping forces.

Dette oppnås ved at hvert enkelt svinghjul har et bestemt treghetsmoment og fjærforbindelse(r) (5, 6) i forhold til massene og treghetsmomentene til flottøren (1), søylen (2) og sjøankerene (3,4). This is achieved by each individual flywheel having a specific moment of inertia and spring connection(s) (5, 6) in relation to the masses and moments of inertia of the float (1), the column (2) and the sea anchors (3,4).

Fordelen som oppnås er at kraftpriser med ulik størrelse og som kommer på forskjellige tidspunkt fra bevegelsesdemperene kan absorberes uten bruk av et kontroll- og reguleringssystem som må beregne riktig størrelse på demperkraften, start og varighet av demperkraften ut ifra konfinnerlig varierende bølgekrefter. The advantage achieved is that power prices of different sizes and which come at different times from the motion dampers can be absorbed without the use of a control and regulation system which must calculate the correct size of the damping force, start and duration of the damping force based on finitely varying wave forces.

Foreliggende oppfinnelse er vist på følgende vedlagte skisser The present invention is shown in the following attached sketches

Figur 1 og 2 viser beregmugsmodell for en bølgekraftomfbrmer som har en ringformet flottør (1) montert rundt en flyende søyle (2) med to eller flere sjøanker (3, 4) koblet i serie til nederste ende av søylen. Figur 2 viser beregnmgsmodeO for turbin (5) og svinghjiil (6, 7). Eventuelle gir mellom komponentene er ikke vist. Betegnelsene i figuren betyr følgende: Figures 1 and 2 show a calculation model for a wave power converter which has an annular float (1) mounted around a flying column (2) with two or more sea anchors (3, 4) connected in series to the lower end of the column. Figure 2 shows the calculation mode for turbine (5) and slewing ring (6, 7). Any gears between the components are not shown. The designations in the figure mean the following:

Fi = innkommende krafrpulser fra bevegelsesdemperene (Dl, D2, D3) Fi = incoming power pulses from the motion dampers (Dl, D2, D3)

Fsl = kraft fra turbin (5) ril svinghjul (6) Fsl = power from turbine (5) ril flywheel (6)

Fs2 = kraft fra svinghjul (6) til svinghjul (7) Fs2 = force from flywheel (6) to flywheel (7)

Fo = kraft fra svinghjul ( 7) til utstyr som utnytter energien for eks. elektrisk generator Fo = power from flywheel ( 7) to equipment that utilizes the energy, e.g. electric generator

Det kan også inngå fjæiforbindelse mellom svmghjulet (7) og tilkoblet utstyr som for eks en elektrisk generator. Figurene er primært ment for å forklare prinsippet for foreliggende oppfinnelse og inneholder derfor ikke alle nødvendige detaljer. There can also be a spring connection between the swimming wheel (7) and connected equipment such as an electric generator. The figures are primarily intended to explain the principle of the present invention and therefore do not contain all necessary details.

Claims

1. Method for transforming the energy in the ocean and sea waves into energy states suitable for utilization, where the method includes a float (1) which swings vertically, horizontally or rotates about horizontal axes during the generation of sea waves, and where the extraction of energy takes place by dampening relative movements between the float and a floating counterweight, where the damping forces between float and counterweight are transferred hydraulically or pneumatically to a turbine, characterized by a series of vertically series-connected counterweights (3, 4) where the mass of each counterweight includes self-weight and hydrodynamic additional mass, and where the counterweights (3, 4) are connected to each other and to the float (1) with spring connections (EL2, K3), where the mass of each counter-hold (3, 4) and the stiffnesses of the associated spring connection T(K2, K3) are adapted so that each counter-hold (3, 4 ) including hydrodynamic additional mass, oscillates with a natural frequency that induces oscillations and resonance in at least one of the other counter-holds (2,3,4) and float (1).

2. Method according to claim 1 characterized in that the method additionally comprises at least one floating counter-hold for turning movements (2), where said counter-hold is connected to the float (1) with spring connections (Kl), and where the moment of inertia of each counter-hold and the stiffnesses of the associated spring-foi connection (Kl) are adapted so that each counter support (2), including hydrodynamic additional mass, oscillates with a natural frequency that induces oscillations and resonance in at least one of the other vertical counter supports (3, 4), other counter supports for turning movements and float (1).

3. Method according to claims 1 and 2 characterized in that the damping forces from the motion dampers (Dl, D2, D3) are absorbed by a number of series-connected flywheels (6, 7), where each individual flywheel has spring connections (K5, K6) to each other, to the turbine (5) and to the arm connected equipment which for for example, an electric generator, and where each individual flywheel has a specific moment of inertia and stiffness in the spring connections which are adapted to the masses, moments of inertia and natural frequencies of the float (1) and the counter-holds (2,3,4).

4. Method according to claims 1, 2 and 3 characterized in that the shear forces between the floats (1) and the counter-holds (2, 3, 4) are transmitted pneumatically or hydraulically to at least 2 parallel-coupled turbines (5) which are in turn connected to one or more series-connected flywheels (6, 7) in accordance with claim 3,

5. Method according to claims 1, 2 and 4 characterized by the fact that each of the counter-holds for vertical movement readings and turning movements (2, 3, 4) includes at least one floating water chamber where the mass of water in the chamber is arranged to oscillate with the counter-holds,

6. Method according to claims 1, 2, 4 and 5 characterized in that the wave power converter is uncontrolled with a control system that automatically adjusts the stiffnesses of the spring elements (K2, K3) between the counter-holders (3, 4) for vertical movements, the spring connections (Kl) between the counter-holders (2) tor turning movements and the stiffnesses of the spring elements (K5, K6) between the turbine (5) and the flywheels (6, 7) and the stiffness of the spring connections to other equipment connected to said flywheel