OCEAN CURRENT POWER PLANT

Abstract

An ocean current power plant with an electric generator and a turbine, which comprises a stator and a rotor that is rotatable about the stator, for driving the electric generator. The rotor comprises a plurality of rotor arms, which respectively have a carrier mechanism and multiple rotor blades that are pivotably mounted on the carrier mechanism.

Claims

1. A current power plant for use in a current of an ocean, comprising an electric generator, and a turbine, which comprises a stator and a rotor that is rotatable about the stator, for driving the electric generator, wherein the rotor comprises a plurality of rotor arms, which respectively have a carrier mechanism and multiple rotor blades that are pivotably mounted on the carrier mechanism.

2. The ocean current power plant according to claim 1, wherein one, multiple or each of the rotor arms comprises a pivoting mechanism that is configured to pivot multiple or all rotor blades of a respective rotor arm simultaneously.

3. The ocean current power plant according to claim 2, wherein the ocean current power plant furthermore comprises a pivoting adjustment mechanism that is configured to adjust the pivoting mechanisms in dependence on a respective current rotational position of the respective rotor arm.

4. The ocean current power plant according to claim 1, which furthermore comprises an adjusting mechanism that is configured to adapt the ocean current power plant to alternating inflow directions occurring with tidal changes.

5. The ocean current power plant according to claim 1, wherein one, multiple or each of the rotor arms is fastened on a central element of the rotor so as to be pivotable parallel to a rotational axis of the rotor.

6. The ocean current power plant according to claim 5, which furthermore comprises a wave generator formed as a hydraulic system that is configured to be acted upon by respective pivoting movements of at least one rotor arm and for thereby converting respective wave energy into electric energy.

7. The ocean current power plant according to claim 1, which comprises one or more buoyancy bodies configured to hold one or more elements of the ocean current power plant on a water surface in a floating manner.

8. The ocean current power plant according to claim 7, wherein at least one buoyancy body is fixed on the carrier mechanism of one of the respective rotor arms.

9. The ocean current power plant according to claim 1, wherein the stator is rigid.

10. The ocean current power plant according to claim 1, wherein the stator comprises a mast with a base for being anchored on a floor of the ocean or on a foundation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Preferred exemplary embodiments of the invention are described in greater detail below with reference to the drawings. It goes without saying that individual elements and components may also be combined in a different way than in the illustrations. Reference symbols for corresponding elements are used comprehensively in all figures and, if applicable, not described anew for each figure.

[0063] In the Schematic Drawings:

[0064] FIG. 1 shows an exemplary embodiment of an inventive ocean current power plant in the form of a sectioned side view;

[0065] FIG. 2 shows a central unit of an exemplary inventive ocean current power plant viewed from a direction perpendicular to the rotational axis.

[0066] FIG. 3 shows a central unit of an exemplary embodiment of an inventive ocean current power plant in the region of the rotor, namely in the form of a section orthogonal to the rotational axis of the rotor;

[0067] FIG. 4 shows a rotor arm of an exemplary embodiment of an inventive ocean current power plant with a pivoting mechanism;

[0068] FIG. 5 shows a rotor blade of an exemplary inventive ocean current power plant with its rotor blade suspension on a rotor aim;

[0069] FIG. 6a shows the rotor of an exemplary inventive ocean current power plant viewed in the direction along the rotational axis;

[0070] FIG. 6b shows an illustration of the function of a pivoting adjustment mechanism of an exemplary embodiment of an inventive ocean current power plant; and

[0071] FIG. 7 shows part of an exemplary inventive ocean current power plant with wave generator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0072] FIG. 1 shows an exemplary embodiment of an inventive ocean current power plant 1 in the form of a sectioned view from a direction extending perpendicular to the rotational axis X, which in the present example is aligned vertically, wherein the ocean current power plant stands on the ocean floor G in an intended operational alignment. In the present example, an inflow direction S extends horizontally and therefore, particularly, perpendicular to the rotational axis X.

[0073] The ocean current power plant 1 comprises an electric generator, which in the present example is arranged in a housing 21 of a central unit 100 and not visible in FIG. 1. The ocean current power plant 1 furthermore comprises a turbine with a rotor 10 and an immovable stator 30, which in the present example is realized in the form of a rigid mast 30a with a base 30b in the form of a flange for being anchored on a foundation 30c.

[0074] It is preferred that the mast 30a has, at least regionally, a gearwheel structure on its circumferential surface and, therefore, is at least regionally designed in the form of a spline shaft (not visible in the figure).

[0075] In an installed ocean current power plant 1, the length of the mast 30a (measured in the direction of the rotational axis X) preferably is adapted to the installation site, particularly to a local water depth at chart datum, a locally occurring tidal range and a predefined safety factor. These parameters also define a required length of the mast 30a in comparison with a height of the housing 21.

[0076] A length of the mast 30a, particularly, may amount to at least 7 m, at least 8 m or at least 9 m and/or no more than 15 m, no more than 13 m or no more than 11 m. These lengths advantageously allow the installation at different suitable installation sites. A diameter of the mast 30a orthogonal to the longitudinal axis preferably can amount to at least 30 cm or at least 40 cm and/or no more than 70 cm or no more than 60 cm.

[0077] The mast 30a, particularly, may be made of shipbuilding steel. It is preferred that the foundation 30c is at least partially made of reinforced concrete. Its diameter on the ocean floor G preferably lies between 4 m and 8 m, particularly between 5 m and 7 m. A submarine cable connection may be embedded therein.

[0078] The rotor 10 of the ocean current power plant 1 comprises multiple rotor arms 11, e.g., four, five, six, seven or eight rotor arms. Two rotor arms 11 are visible in FIG. 1.

[0079] In this case, the rotor arms 11 respectively comprise a carrier mechanism 12, which in the present example points away from the stator 30 with respect to its longitudinal extent; in the example shown, its longitudinal extent particularly runs radially (referred to the rotational axis X of the rotor 10). A buoyancy body 13 is respectively fixed on the carrier mechanism 12 and floats on the water surface W when the ocean current power plant 1 is in use, such that the respective rotor arm 10 is held at a constant water depth and, in particular, visible for marine traffic. The respective buoyancy bodies 13 are movably fastened on the central unit 100, e.g., suspended thereon.

[0080] In the exemplary embodiment shown, the buoyancy bodies 13 respectively extend over the length of the respective rotor arm 10 up to a radially outer region and thereby indicate a size of the ocean current power plant 1. At least one of the buoyancy bodies 13 may be marked in color for better visibility, for example with a (e.g., yellow) marking. According to advantageous embodiments, at least one of the buoyancy bodies is designed in the form of a closed shipbuilding body. It may be manufactured, for example, from a conical flat oval pipe. It may have at least one fastening flange (that is not illustrated in the figure) for being connected to the carrier mechanism 12.

[0081] In the present example, the carrier mechanisms 12 of the rotor arms 11 are respectively designed in the form of a frame, which encircles the multiple (preferably at least three and/or no more than eight or no more than six) rotor blades 14 that likewise belong to the respective rotor arm 11; each rotor arm 11 has four rotor blades 14 in the exemplary embodiment shown.

[0082] The respective rotor blades 14 can be pivoted about a respective pivoting axis that extends in the longitudinal direction of the respective rotor blade. The carrier mechanisms 12 of each rotor arm 10 have connecting braces 12a adjacent to each rotor blade 14 in order to stabilize the blade mountings.

[0083] The carrier mechanism 12, the buoyancy body 13 and/or the rotor blades 14 preferably are comprised of, at least partially, shipbuilding steel. The mountings for the rotor blades 14 preferably are comprised of, at least partially, special steel.

[0084] FIG. 2 shows a central unit 100 of an exemplary inventive ocean current power plant viewed from a direction perpendicular to the rotational axis X, wherein this figure also provides a view into the housing 21 that, particularly, encloses an electric generator 22 of the ocean current power plant. According to advantageous embodiments, the housing has a round (circular) cross section (perpendicular to the rotational axis X). Other preferred elements of an electronics system, e.g., control electronics with an on-board computer, a transmitter for transmitting data and/or at least one sensor device, likewise may (although not shown) be at least partially arranged within the housing 21.

[0085] The electric generator 22 converts the rotation of a drive shaft 22a, which is driven by a central element of the rotor in the form of a rotator 16 via a gearwheel 23, into electric energy that preferably can be fed into an electrical network via a not-shown electric line with submarine cable connection and a connected submarine cable. The rotator 16 is set in rotation by rotor arms that are not illustrated in FIG. 2; the rotor arms are fastened, e.g., suspended, on the rotator 16 and in turn moved by a respective ocean current. According to advantageous embodiments of an inventive ocean current power plant, the rotator 16 is thereby driven with a rotational speed of 50% to 90%, preferably 60% to 80%, of an inflow speed of 1 m/sec to 2 m/sec.

[0086] The central unit 100 furthermore comprises a pivoting adjustment mechanism 24 (which in the present example is realized in the form of a control disk) for adjusting respective pivoting mechanisms of the rotor arms in dependence on their respective current rotational position, wherein this is described in greater detail below, in particular, with reference to FIGS. 6a, 6b. In this case, the rotator 16 is rotatable relative to the pivoting adjustment mechanism 24 (about the rotational axis X). In the intended operational alignment of the ocean current power plant (or its central unit 100) shown in the figure, the pivoting adjustment mechanism 24 is arranged underneath the rotator 16.

[0087] The housing 21 likewise encloses an adjusting motor 25a of an adjustment mechanism 25, which in the present example also comprises a shaft 25b and a gearwheel 25c and is designed for adjusting, i.e., correspondingly adapting, the ocean current power plant to alternating inflow directions occurring with tidal changes. To this end, the gearwheel 25c, which is set in rotation by the adjusting motor 25a via the shaft 25b, engages into a gear structure in the (radially) inner surface of the pivoting adjustment mechanism 24, wherein a gear structure on a radially outer surface of the mast 30a of the stator 30 serves as abutment. In this way, the pivoting adjustment mechanism 24 is rotated about the stator 30, preferably by 180°, together with the rotator 16 fixed thereon. The position of the pivoting adjustment mechanism 24 (that is not designed rotationally symmetrical) relative to the flow direction, which reverses with the tidal change, influences the pivoting positions of the respective rotor blades on the rotor arms as described in greater detail below, in particular, with reference to FIGS. 6a, 6b.

[0088] Another gearwheel 27 is in idle mode and merely serves for stabilizing the pivoting adjustment mechanism 24. A gearwheel 28 similarly is in idle mode and merely serves for stabilizing the rotator 16.

[0089] In the present example, the central unit 100 furthermore comprises an annular buoyancy body 26, on which the pivoting adjustment mechanism 24 is fastened, wherein this buoyancy body is designed for holding the pivoting adjustment mechanism on a water surface W in a floating manner. A (not-shown) buoyancy body may be arranged in the space enclosed by the housing 21 alternatively or additionally to the annular buoyancy body 26.

[0090] FIG. 3 shows the annular rotator 16 from the direction of the housing 21 (which is not illustrated in FIG. 2) together with the subjacent pivoting adjustment mechanism 24, the mast 30a of the stator 30, the gearwheel 23 connected to the drive shaft of the electric generator, the gearwheel 25c of the adjustment mechanism 25 and the additional gearwheels 27 and 28. In the present example, the rotator 16 has on its outer circumference eight stops 16a for anchoring (e.g., by means of bolts) not-shown rotor arms, by means of which it is set in rotation about the rotational axis X in the rotating direction R as a result of an ocean current. Buoyancy bodies on the rotor arms, as well as the buoyancy body 26 illustrated in FIG. 2, are designed for holding the rotator 16 on a water surface, particularly at water line.

[0091] The rotator 16 has on its edge surface facing the rotational axis X a (not-shown) gear structure in the form of a gear ring, which engages into the gearwheel 23 and thereby drives the (not-shown) electric generator via its drive shaft.

[0092] The pivoting adjustment mechanism 24 in the form of a disk likewise has a (not-shown) gear structure in the form of a gear ring on its edge surface facing the rotational axis X. The gearwheel 25c of the adjustment mechanism 25 engages into this gear structure and furthermore into a gear structure on the outer surface of the mast 30a. When the gearwheel 25c is set in rotation by the adjusting motor 25a (see FIG. 2), the pivoting adjustment mechanism 24 is respectively rotated about the mast 30a or the rotational axis X (preferably together with the housing 21 and at least some of the components arranged therein). In this way, the ocean current power plant can be adapted to the alternating inflow directions occurring with tidal changes. The adjustment mechanism 25 furthermore serves for locking the pivoting adjustment mechanism 24 while the adjusting motor is at a standstill during the operation of the ocean current power plant.

[0093] According to advantageous embodiments, the rotator 16 comprises a forged steel ring. During the operation of the ocean current power plant, it is preferably held on the water surface in a floating manner by buoyancy bodies 13 of the rotor arms 11, e.g., buoyancy bodies of the type illustrated in FIG. 1.

[0094] FIG. 4 schematically shows a rotor arm 11 with a carrier mechanism 12, which in the present example has a thickened suspension 12b for being connected to a (not-shown) rotator by means of two bolts. In the exemplary embodiment shown, four rotor blades 14 are respectively mounted on the carrier mechanism 12 so as to be pivotable about an associated pivoting axis V; in this case, respective journals 14a of the rotor blades 14 respectively engage into a (not-shown) bearing bush in the form of a recess in the carrier mechanism 12.

[0095] In this case, the pivoting movement can be accomplished simultaneously for all rotor blades 14 of the rotor arm 11 by means of a pivoting mechanism 15, which in the present example is realized in the form of a push rod and engages on a respective control pin 14b of each rotor blade 14. The rotor blades 14 of the rotor arm 11 can be simultaneously pivoted about their respective pivoting axis V by displacing the push rod in the direction of its longitudinal axis as indicated with broken lines in FIG. 4. A maximum pivoting angle γ preferably is limited; the rotor blades can be pivoted by +/−45°, preferably by no more than +/−40° or +/−30°, relative to a position I, in which they lie transverse to a longitudinal extent of the rotor aim (unhatched in FIG. 4). In FIG. 4, a position II after a maximum pivoting movement by the pivoting angle γ of presently 30° is indicated with hatched rotor blades.

[0096] The operation of the pivoting mechanism 15 preferably is realized by means of a control head 15a on its end facing the (not-shown) rotator, wherein the control head engages into a rail or groove that acts as pivoting adjustment mechanism; this is described in greater detail further below with reference to FIG. 6b.

[0097] FIG. 5 shows a rotor arm 11 of an exemplary inventive ocean current power plant in the form of a section along a rotating direction R of the rotor arm 11 (i.e., perpendicular to its longitudinal alignment). In this case, the rotor arm 11 is illustrated in an intended operational alignment, in which the buoyancy body 13 is fastened on top of the carrier mechanism 12 and the rotor blades, particularly the rotor blade 14 shown, preferably extend vertically referred to their longitudinal alignment.

[0098] FIG. 5 particularly shows a rotor blade suspension of the rotor blade 14 on the carrier mechanism 12: journals 14a, 14c on opposite ends of the rotor blade 14 respectively engage into a bearing bush 12c, 12d of the carrier mechanism 12. The bearings consisting of journals 14a, 14c and bearing bushes 12c, 12d preferably run without any lubricant other than water.

[0099] A pivoting mechanism 15, which in the present example is realized in the form of a push rod extending perpendicular to the plane of projection of FIG. 5, engages on a control pin 14b on the upper end of the rotor blade 14 and can thereby cause the above-described pivoting movement about the pivoting axis V.

[0100] In the present example, the rotor blade 14 has an advantageous blade shape with a NACA profile. It particularly has an elliptical cross section (perpendicular to the longitudinal alignment). Its blade surfaces preferably are designed in the form of surfaces of a hollow, welded shipbuilding construction that is provided with ribs, wherein the journals 14a, 14c preferably are welded to the ends of this construction.

[0101] The blade surfaces have a length L and a width B that is defined by the distance of an inflow edge 14d from an outflow edge 14e of the rotor blade 14. The rotor blade furthermore has a (maximum) thickness D that is measured in the direction perpendicular to the length L and the width B. In this case, the blade width B preferably is chosen in dependence on a respective length of the associated rotor arm just like the number of rotor blades and the maximum pivoting angle γ; the length of the rotor aim may amount, for example, to at least 8 m, at least 10 m or at least 12 m and/or no more than 16 m or no more than 13 m.

[0102] In these examples, the width B of the rotor blades 14 may lie, for example, between 1 m and 3 m, particularly in the range between 1.5 m and 2.5 m, and/or the thickness D may lie in the range between 20 cm and 60 cm, particularly in the range between 30 cm and 50 cm.

[0103] The length L of the blade surfaces (and therefore the immersion depth) preferably is adapted to a usable water depth (at low tide) in the (intended) installation position; for example, it may be 1 m to 2 m smaller than this water depth. The installation of the ocean current power plant 1 in many suitable installation positions can be advantageously realized with embodiments, in which the length L lies in the range between 6 m and 10 m, particularly in the range between 7 m and 9 m.

[0104] The journals 14a, 14c are spaced apart from the outflow edge 14e by a distance B1, wherein 0.2B≤B1≤0.3B preferably applies. The control pin 14b is spaced apart from the outflow edge 14e by a distance B2, wherein it is alternatively or additionally preferred that 0.6B≤B2≤0.9B or even 0.7B≤B2≤0.8B applies.

[0105] FIG. 6a shows the rotor 10 of an inventive ocean current power plant viewed in the direction along the rotational axis X; the drawing therefore corresponds to a top view of the installed ocean current power plant. It shows that the rotor 10 has in the present example eight rotor arms 11 that are fastened on the rotator 16 and respectively provided with four rotor blades 14, wherein the rotor has in a counterclockwise rotating direction R an effective area E in the form of a sector of approximately 270°. The illustration in FIG. 6a shows the rotor in a coordinate system, in which the effective area E lies axially symmetrical to the x-axis.

[0106] The rotor blades 14 can be pivoted into a respective alignment that depends on a respective current rotational position of the respective rotor arm 11 by means of the pivoting mechanisms of the rotor arms 11, which are not illustrated in FIG. 6a, and a pivoting adjustment mechanism, which is likewise not illustrated in FIG. 6a. The respective rotational position in FIG. 6a is defined by the angle α between the respective rotor aim 11 and the x-axis; however, the angle is in this figure only indicated for one of the rotor arms 11 in order to provide a better overview. In this case, the y-axis extends in the inflow direction S and its values increase opposite to the inflow direction S. The angle α=0 particularly lies in the rotational position 0, in which only counterpressure has to be overcome, and the angle α=90° lies in the rotational position facing the inflow direction.

[0107] Respective angles θ (of which only one is indicated in FIG. 6a) show a pivoting movement of the rotor blades toward the inside (i.e., toward the rotational axis X) or toward the outside (away from the rotational axis X) starting from an alignment tangential to the rotating direction. In the present example, the values of β are advantageously adjusted in dependence on the rotational position and therefore in dependence on the angle α as shown in the following table:

TABLE-US-00001 α β  0° 0°  45° 15° inward  90° 30° inward 135° 30° inward 180° 30° inward 225° 0° 270° 30° outward 315° 15° outward 360° = 0 0°

[0108] FIG. 6b elucidates how a pivoting adjustment mechanism 24, which in the present example is realized in the form of a control disk, can correspondingly adjust the pivoting mechanisms 15 of the rotor arms in dependence on a respective current rotational position of the respective rotor arm:

[0109] To this end, the pivoting adjustment mechanism 24 has a control groove 24a with a rotationally asymmetrical extent around the rotational axis X, of which only the sections belonging to the positions of the rotor arms illustrated in FIG. 6a are shown in FIG. 6b, wherein a control head 15a on the end of a pivoting mechanism 15 in the form of a push rod engages into the control groove. When the rotor is rotated by means of the pivoting adjustment mechanism 24, the control heads 15a are guided about the rotational axis X along the control groove 24a and in the process assume different distances from the rotational axis X. In the present example, this causes the respective different pivoting movements of the rotor blades in accordance with the table shown above. The directional tendency is indicated with arrows in FIG. 6b.

[0110] FIG. 7 shows a rotor arm 11 that is suspended on the rotator 16. A control head 15a is arranged on the end of a pivoting mechanism 15, which in the present example is designed in the form of a push rod and only partially and schematically illustrated in order to provide a better overview, wherein the control head engages into the control groove 24a of the pivoting adjustment mechanism 24. A double arrow in FIG. 7 indicates that a rotation of the rotator 16 about the rotational axis X changes its distance from the control head 15a and thereby causes a respective adjustment of the pivoting mechanism 15 in dependence on a respective current rotational position of the respective rotor arm 11, which in turn implies a respective pivoting movement of the rotor blades 14.

[0111] In the exemplary embodiment shown, the rotor arm 11 can be pivoted by a deflection angle parallel to the rotational axis X (in the present example upward and downward) as indicated with another double arrow in FIG. 7. Such pivoting movements are caused by wave movements and the buoyancy body 13. The pivoting mechanism 15 therefore can also be pivoted accordingly as schematically indicated with positions drawn with broken lines in FIG. 7. The pivoting mechanism 15 has a joint in the exemplary embodiment shown; this joint, particularly, may be designed in the form of a universal joint. It is preferred that the pivoting mechanism 15 alternatively or additionally lies in one plane with the carrier mechanism 12.

[0112] In the present example, the pivotability of the rotor aim is limited by means of a hydraulic system 17 comprising a hydraulic damper, e.g., respectively limited to no more than 20° or no more than 15° in both directions (upward and downward). The hydraulic system 17 is acted upon by respective pivoting movement of the rotor arm 11 and can thereby convert occurring movements of the ocean into electric energy.

[0113] The invention discloses an ocean current power plant 1 with an electric generator 22 and a turbine, which comprises a stator 30 and a rotor 10 that is rotatable about the stator, for driving the electric generator 22. The rotor comprises a plurality of rotor arms 11, which respectively have a carrier mechanism 12 and multiple rotor blades 14 that are pivotably mounted on the carrier mechanism.

[0114] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.

LIST OF REFERENCE SYMBOLS

[0115] 1 Ocean current power plant [0116] 10 Rotor [0117] 11 Rotor arm [0118] 12 Carrier mechanism [0119] 12a Connecting brace [0120] 12b Suspension [0121] 12c, 12d Bearing bush [0122] 13 Buoyancy body [0123] 14 Rotor blade [0124] 14a, 14c Journal [0125] 14b Control pin [0126] 14d Inflow edge [0127] 14e Outflow edge [0128] 15 Pivoting mechanism [0129] 15a Control head [0130] 16 Central element/rotator [0131] 16a Stop [0132] 17 Hydraulic system [0133] 21 Housing [0134] 22 Electric generator [0135] 22a Drive shaft [0136] 23 Gearwheel [0137] 24 Pivoting adjustment mechanism [0138] 25 Adjustment mechanism [0139] 25a Adjusting motor [0140] 25b Shaft [0141] 25c Gearwheel [0142] 26 Buoyancy body [0143] 27, 28 Gearwheel [0144] 30 Stator [0145] 30a Mast [0146] 30b Base [0147] 30c Foundation [0148] 100 Central unit [0149] B Rotor blade width [0150] B.sub.1 Distance of journals from outflow edge [0151] B.sub.2 Distance of control pin from outflow edge [0152] D Rotor blade thickness [0153] E Effective area [0154] G Ocean floor [0155] L Rotor blade length [0156] R Rotating direction [0157] S Inflow direction [0158] V Pivoting axis [0159] W Water surface [0160] X Rotational axis