NO20211014A1 - Wave energy converter with adjustable natural frequency - Google Patents

Wave energy converter with adjustable natural frequency Download PDF

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Publication number
NO20211014A1
NO20211014A1 NO20211014A NO20211014A NO20211014A1 NO 20211014 A1 NO20211014 A1 NO 20211014A1 NO 20211014 A NO20211014 A NO 20211014A NO 20211014 A NO20211014 A NO 20211014A NO 20211014 A1 NO20211014 A1 NO 20211014A1
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NO
Norway
Prior art keywords
turbine
keel
rotation
float
floating body
Prior art date
Application number
NO20211014A
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Norwegian (no)
Inventor
Inge Bakke
Original Assignee
Inge Bakke
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Filing date
Publication date
Application filed by Inge Bakke filed Critical Inge Bakke
Priority to NO20211014A priority Critical patent/NO20211014A1/en
Publication of NO20211014A1 publication Critical patent/NO20211014A1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03B—MACHINES OR ENGINES FOR LIQUIDS
    • F03B13/00—Adaptations of machines or engines for special use; Combinations of machines or engines with driving or driven apparatus; Power stations or aggregates
    • F03B13/10—Submerged units incorporating electric generators or motors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03B—MACHINES OR ENGINES FOR LIQUIDS
    • F03B13/00—Adaptations of machines or engines for special use; Combinations of machines or engines with driving or driven apparatus; Power stations or aggregates
    • F03B13/12—Adaptations of machines or engines for special use; Combinations of machines or engines with driving or driven apparatus; Power stations or aggregates characterised by using wave or tide energy
    • F03B13/14—Adaptations of machines or engines for special use; Combinations of machines or engines with driving or driven apparatus; Power stations or aggregates characterised by using wave or tide energy using wave energy
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B39/00—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B39/00—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude
    • B63B39/02—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by displacement of masses
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B39/00—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude
    • B63B39/02—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by displacement of masses
    • B63B39/03—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by displacement of masses by transferring liquids
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/20—Hydro energy
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/30—Energy from the sea, e.g. using wave energy or salinity gradient

Description

Beskrivelse Description

Oppfinnelsen angår en innretning, kalt «Bølgeenergiomformer med justerbar egenfrekvens», i denne beskrivelsen forkortet til «omformer», som skal omforme bølgeenergi til elektrisk strøm (figur 1). Den består av et avlangt flytende legeme (2) som er utstyrt med en dyp og smal kjøl (3), på tvers av flyterens lengderetning, med tre forlengelser nederst hvortil det er festet en turbin (4) med to motsatt roterende rotorer (5 og 6). Rotorenes turbinblad (16) består av et fleksibelt materiale som omgir en fast, ikke-roterende bærende aksling (17) som bladet kan rotere omkring (19, 20 og 21). Denne rotasjonen er begrenset i bladets ytre ende der solide stenger (18) festet til akslingen holder, under alle forhold, denne del av turbinbladet parallelt med rotorens rotasjonsplan (22). Denne konstruksjonen fører til at bladet vrir seg i økende grad inn mot roten når det utsettes for press fra en vannstrøm, eller selv beveger seg gjennom vannet. Dette fører til at bladet inntar en gunstig angrepsvinkel for utnyttelse av bevegelsen til rotasjonskraft. I en oscillerende vannstrøm eller turbinbevegelse vil turbinbladet hele tiden drive rotoren i samme rotasjonsretning. The invention relates to a device, called "Wave energy converter with adjustable natural frequency", in this description abbreviated to "converter", which will convert wave energy into electrical current (figure 1). It consists of an elongated floating body (2) which is equipped with a deep and narrow keel (3), across the longitudinal direction of the float, with three extensions at the bottom to which is attached a turbine (4) with two counter-rotating rotors (5 and 6). The rotor's turbine blade (16) consists of a flexible material that surrounds a fixed, non-rotating supporting shaft (17) around which the blade can rotate (19, 20 and 21). This rotation is limited at the blade's outer end where solid rods (18) attached to the shaft hold, under all conditions, this part of the turbine blade parallel to the rotor's plane of rotation (22). This construction causes the blade to twist increasingly towards the root when it is subjected to pressure from a stream of water, or even moves through the water. This causes the blade to adopt a favorable angle of attack for utilizing the movement for rotational power. In an oscillating water flow or turbine motion, the turbine blade will constantly drive the rotor in the same direction of rotation.

De to motsatt roterende rotorenes akslinger går inn i et gir (7) som overføre rotasjonskraften fra de to rotorene til en aksling (8) som driver en generator (11) i flyteren. Giret vil ha utveksling slik at generatorens turtall blir høyere enn rotorenes. De to rotorenes rotasjonshastighet kan være låst til hverandre i giret (8) eller ikke. Det kan også innrettes gir i flyteren for å øke rotasjonshastigheten i generatoren ytterligere. The shafts of the two counter-rotating rotors go into a gear (7) which transfers the rotational force from the two rotors to a shaft (8) which drives a generator (11) in the float. The gear will have a ratio so that the speed of the generator is higher than that of the rotors. The rotation speed of the two rotors can be locked to each other in the gear (8) or not. Gears can also be fitted in the float to further increase the rotation speed in the generator.

Omformeren har to sammenkoblede, lukkede vanntanker (9). Den ene lavt i flyteren og øvre del av kjølen. Den andre i et tårn (12) som er solid festet til flyterens dekk. Ved hjelp av to rør, ett for vann (13) og ett for luft (14) og en pumpe (10a), kan en vannmengde flyttes mellom de to tankene. The converter has two interconnected, closed water tanks (9). One low in the float and upper part of the keel. The other in a tower (12) which is solidly attached to the float's deck. With the help of two pipes, one for water (13) and one for air (14) and a pump (10a), a quantity of water can be moved between the two tanks.

Tankene må være så store at vannmengden som kan forflyttes gir betydelige endringer i vertikal retning av omformerens tyngdepunkt. The tanks must be so large that the amount of water that can be moved causes significant changes in the vertical direction of the converter's center of gravity.

Flyteren har utstikkende fester for forankring (15) på hver side av flyteren i omformerens rotasjonsakse for pitchbevegelser. The float has protruding fasteners for anchoring (15) on each side of the float in the inverter's axis of rotation for pitch movements.

Forankringen skjer med et system av to stive forankringskabler eller stenger (26a), som holder fast avstand til en flytende bom (27) som holder kablene vekk fra flyterens sider, et flytende forankringstau (26b), fra et svivelfeste (28) midt på bommen fram til en flytebøye (29) som er forankret med kjetting (26c), til bunnfeste (30). The anchoring takes place with a system of two rigid anchoring cables or rods (26a), which maintain a fixed distance to a floating boom (27) that keeps the cables away from the sides of the float, a floating anchoring rope (26b), from a swivel mount (28) in the middle of the boom up to a buoy (29) which is anchored with a chain (26c), to the bottom attachment (30).

Ved å være festet til kun ett bunnfeste vil omformeren dreie seg etter vind og bølger slik at kjølens lengderetning og turbinens rotasjonsakse vil være tilnærmet vinkelrett på bølgefrontene mens flyteren ligge parallelt med disse. Avstanden mellom flyteren og bommen må være så stor at kjølen ikke under noen omstendigheter kan berøre bommen. De stive kablene eller stengene (26a) mellom forankringsfestene (15) og den flytende bommen (27) må sikre at bommen ikke kommer inntil flyteren, ei heller til flytebøyen (29), i stille vær når det ikke er strekk i forankringssystemet. By being attached to only one bottom attachment, the converter will turn according to wind and waves so that the longitudinal direction of the keel and the axis of rotation of the turbine will be approximately perpendicular to the wave fronts, while the float lies parallel to them. The distance between the float and the boom must be so great that the keel cannot under any circumstances touch the boom. The rigid cables or rods (26a) between the anchoring fasteners (15) and the floating boom (27) must ensure that the boom does not come close to the float, nor to the buoy (29), in calm weather when there is no tension in the anchoring system.

Flytetauet (26b) mellom bommen og flytebøyen (29) sikrer at heller ikke dette kommer nær turbinen. Når det ikke er strekk i systemet, vil kjettingen (26c) fra flytebøyen (29) ned til bunnfeste (30) henge rett ned. Siden den flytende bommen (27) og de stive kablene eller stengene (26a) holder flyteren vekk fra flytebøyen (29) vil heller ikke kjettingen (26c) kunne komme nær turbinen. The flotation rope (26b) between the boom and the flotation buoy (29) ensures that this does not come close to the turbine either. When there is no tension in the system, the chain (26c) from the buoy (29) down to the bottom attachment (30) will hang straight down. Since the floating boom (27) and the rigid cables or rods (26a) keep the float away from the buoy (29), the chain (26c) will also not be able to get close to the turbine.

Reparasjon og vedlikehold av omformeren skjer dels gjennom luker (ikke vist) på flyterens dekk, dels ved hjelp av to store tanker (23) i flyterens sider. Disse er utstyrt med pumper (10b) og forbindelse til sjøen. Ved å fylle en av tankene med sjøvann og samtidig flytte vannmengden i de lukkede tankene (9) til tårnet (12) vil omformeren legge seg over på siden (figur 6) slik at turbinen og den ene siden av kjøl og flyter blir tilgjengelig for rengjøring, inspeksjon og reparasjon. Et flytelegeme (24) øverst i tårnet hindrer at omformeren tipper helt rundt. Repair and maintenance of the converter takes place partly through hatches (not shown) on the float's deck, partly using two large tanks (23) in the sides of the float. These are equipped with pumps (10b) and a connection to the sea. By filling one of the tanks with seawater and at the same time moving the amount of water in the closed tanks (9) to the tower (12), the converter will lie over on its side (figure 6) so that the turbine and one side of the keel and floats become available for cleaning , inspection and repair. A floating body (24) at the top of the tower prevents the converter from tipping completely around.

Eksempel på anvendelse Example of application

Oppfinnelsen skal brukes til produksjon av elektrisk energi. Omformeren fungerer ved å bevege turbinen i en pendelbevegelse under flyteren når flyteren gjør pitchbevegelser under påvirkning av bølger. Pitchbevegelsen og dermed turbinens pendelbevegelse i vannet kan økes ved å bringe omformerens egenfrekvens i samsvar med bølgeperioden slik at det oppstår resonans. Dette gjøres ved å regulere vannmengden mellom de to delene i vanntanksystemet (9) ved hjelp av en pumpe (10a). En datamaskin styrer pumpemotoren etter en algoritme som kontinuerlig søker etter innstillingen som gir størst energiutbytte. Forankringssystemet vil ikke hindre pitchbevegelsen. The invention is to be used for the production of electrical energy. The converter works by moving the turbine in a pendulum motion under the float as the float makes pitch movements under the influence of waves. The pitch movement and thus the turbine's pendulum movement in the water can be increased by bringing the converter's natural frequency in line with the wave period so that resonance occurs. This is done by regulating the amount of water between the two parts in the water tank system (9) using a pump (10a). A computer controls the pump motor according to an algorithm that continuously searches for the setting that gives the greatest energy yield. The anchoring system will not impede the pitch movement.

Dette oppnås ved oppfinnelsen This is achieved by the invention

• En flyter med lengderetningen liggende parallelt med bølgefrontene vil få pitchbevegelsen påvirket av en tilsvarende lang bølgefront og motta tilsvarende mye energi. • A float with the longitudinal direction lying parallel to the wave fronts will have its pitch movement affected by a correspondingly long wave front and receive a corresponding amount of energy.

• Den tverrstilte kjølen vil ha en form som i liten grad hindrer flyterens pitchbevegelse. • The transverse keel will have a shape that slightly hinders the float's pitch movement.

• Turbinens plassering nederst i kjølen fører til at den kan få en pendelbevegelse. • The location of the turbine at the bottom of the keel means that it can have a pendulum movement.

• Pendelbevegelsens lengde kan økes ved å regulere omformerens egenfrekvens slik at flyterens pitchbevegelse holdes i resonans med bølgeperioden. • The length of the pendulum movement can be increased by regulating the converter's natural frequency so that the float's pitch movement is kept in resonance with the wave period.

• Pendelbevegelsens lengde kan også økes ved å forlenge kjølen. • The length of the pendulum movement can also be increased by extending the keel.

• Omformerens egenfrekvens kan styres automatisk etter en algoritme for maksimering av energiutbytte og innrette seg etter varierende bølgeforhold. • The converter's natural frequency can be controlled automatically according to an algorithm for maximizing energy yield and adapt to varying wave conditions.

• De to motsatt roterende rotorene opphever hverandres dreiemomenter og utsetter ikke omformeren for vridningskrefter. • The two counter-rotating rotors cancel each other's torques and do not subject the converter to twisting forces.

• Systemet har ikke et endestopp-problem, i dette tilfellet problemer med begrensning av pendelutslag. Hvis utslaget blir så stort at omformeren legger seg helt over på siden, vil videre velt hindres av flytelegemet (24) øverst på tårnet (12). Omformeren kan derfor være i normal drift også under ekstreme bølgeforhold. Hvis det likevel er ønskelig å begrense utslaget, kan systemet bringes ut av resonans med bølgeperioden ved at alt vann i tanksystemet for regulering av tyngdepunktet (9, 10a, 13, 14) samles i den nedre tanken. • Generatorens plassering gir god beskyttelse og lett tilkomst for service. • The system does not have an end stop problem, in this case problems with limitation of pendulum travel. If the impact becomes so great that the converter lies completely on its side, further overturning will be prevented by the floating body (24) at the top of the tower (12). The converter can therefore be in normal operation even under extreme wave conditions. If it is nevertheless desirable to limit the impact, the system can be brought out of resonance with the wave period by collecting all the water in the tank system for regulating the center of gravity (9, 10a, 13, 14) in the lower tank. • The location of the generator provides good protection and easy access for service.

• Det er god plass i flyteren for installasjon av annet utstyr. • There is plenty of space in the float for the installation of other equipment.

• Forankringssystemet hindrer ikke omformerens pitchbevegelse. • The anchoring system does not prevent the inverter's pitch movement.

• Tilkomst til turbinen og til omformerens underside kan skje uten assistanse fra andre fartøyer. • Access to the turbine and to the underside of the converter can be done without assistance from other vessels.

• Forankring i ett enkelt bunnfeste er kostnadsbesparende. • Anchoring in a single bottom bracket is cost-saving.

• Omformeren kan sjøsettes ved kai og slepes til operasjonsområdet. • The converter can be launched at the quay and towed to the operating area.

Claims (1)

PatentkravPatent claims Krav 1Requirements 1 En innretning for omforming av bølgeenergi til elektrisk strøm bestående av et flytelegeme utstyrt med en kjøl hvortil det nederst, med rotasjonsaksen parallelt med kjølen, er festet en turbin med to motsatt roterende rotorer med fleksible turbinblad som gir enveis rotasjon ved turbinens oscillerende pendelbevegelse gjennom vannet når bølgefronter på tvers av kjølens lengderetning og turbinens rotasjonsakse skaper pitchbevegelser hos flytelegemet.A device for converting wave energy into electric current consisting of a floating body equipped with a keel to which, at the bottom, with the axis of rotation parallel to the keel, is attached a turbine with two counter-rotating rotors with flexible turbine blades which provide unidirectional rotation by the turbine's oscillating pendulum movement through the water when wave fronts across the keel's longitudinal direction and the turbine's axis of rotation create pitch movements of the floating body. Krav 2Requirement 2 En innretning i henhold til krav 1, med et system for heving og senkning av innretningens tyngdepunkt for justering av innretningens egenfrekvens slik at den samsvarer med den til enhver tid rådende bølgeperiode.A device according to claim 1, with a system for raising and lowering the device's center of gravity for adjusting the device's natural frequency so that it corresponds to the prevailing wave period at any given time. Krav 3Requirement 3 En innretning i henhold til krav 1 og 2, med vanntanker, pumper og flytelegeme som kan få innretningen til vekselvis å velte over på den ene og den andre siden slik at turbinen og undervannsdelene av innretningen gjøres tilgjengelig for inspeksjon og vedlikehold.A device according to claims 1 and 2, with water tanks, pumps and a floating body which can cause the device to alternately tip over on one side and the other so that the turbine and the underwater parts of the device are made available for inspection and maintenance. Krav 4Requirement 4 En innretning i henhold til krav 1 og 2 med festepunkter for forankring ved innretningens rotasjonsakse for pitchbevegelse. A device according to claims 1 and 2 with attachment points for anchoring at the device's axis of rotation for pitch movement.
NO20211014A 2021-08-23 2021-08-23 Wave energy converter with adjustable natural frequency NO20211014A1 (en)

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NO20211014A NO20211014A1 (en) 2021-08-23 2021-08-23 Wave energy converter with adjustable natural frequency

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NO20211014A NO20211014A1 (en) 2021-08-23 2021-08-23 Wave energy converter with adjustable natural frequency

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NO327567B1 (en) * 2007-02-16 2009-08-17 Hydra Tidal Energy Technology Liquid plants for the production of energy from streams in water
CN113217263A (en) * 2021-05-10 2021-08-06 东北师范大学 Novel energy-gathering duct type self-variable-pitch direct-drive wave power generation device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NO327567B1 (en) * 2007-02-16 2009-08-17 Hydra Tidal Energy Technology Liquid plants for the production of energy from streams in water
CN113217263A (en) * 2021-05-10 2021-08-06 东北师范大学 Novel energy-gathering duct type self-variable-pitch direct-drive wave power generation device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
SOMOSA, M.H. et al., Reduction of tidal turbines hydrodynamic loads employing bend-twist adaptive blades, 3rd International Symposium on Environmental Friendly Energies and Applications (EFEA), november 2014, ISBN 978-1-4799-7517-4, spesielt sammendrag, Section IV og figur 2, Dated: 01.01.0001 *

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