Kinetic modular machine for producing energy from fluid flows

Abstract

A kinetic modular machine for producing electricity from flows, either mono or bi-directional, moving at different speeds, includes one or more turbines that are “open center” and coaxial; a floating/positioning system; and a connection between the kinetic modular machine and a docking. Each turbine has a rotor, a stator, and a synchronous generator. In different configurations, the turbines are structurally, mechanically and electrically independent. The floating/positioning system includes a floater, a wing, and a fixture linking the turbines to the floater, implementing the control of the rotational axes (roll, pitch, yaw), with the wing keeping the machine at a given distance from the shore and the fluid surface. The modular design, having independent turbines, allows for a flexible design, keeping the installation and maintenance costs low.

Claims

1. A modular kinetic machine (M) for producing electricity from fluid flows, the modular kinetic machine being adapted to be floating in a fluid, “open center”, with a swept area fully immersed and perpendicular to flow direction, comprising: one or more turbines (T; where i=1, 2, . . . n) that are mechanically and electrically independent; and a floating/positioning control device (F), wherein each turbine is structurally, mechanically, and electrically independent, by comprising a rotor with blades, a stator, and a built-in generator.

2. The modular kinetic machine (M), according to the claim 1, wherein each rotor and stator comprise parts centered on an axis of the modular kinetic machine rotational, the parts being arranged to cause a minimal radial runout and a minimal out of bound runout among rotational parts.

3. The modular kinetic machine (M), according to the claim 1, wherein a number of blades (5, 10) is a maximum number suitable dimensions and performances of the kinetic modular machine, so as to reduce a load for each blade and allow using materials having a lower structural strength and lower machine weight and costs.

4. The modular kinetic machine (M), according to the claim 1, wherein the one or more turbines have a center hole that is designed using a Di/De (external diameter/center hole diameter) ratio to provide a maximum available energy production.

5. The modular kinetic machine (M), according to the claim 1, wherein the floating/positioning control device (F) comprises at least a buoy (11), a positioning wing (12), and a machine buoy link fixture (13), wherein the buoy (11) is designed to allow positioning the modular kinetic machine in terms of optimal depth and stable transient mood; and wherein the positioning wing (12) is installed out of the turbine, in proximity to the buoy (11) and it is linked to the turbine by one or more beams or any other frame (13) configured fir linking, allowing the modular kinetic machine to reach a desired distance from a shore or an anchoring point.

6. The modular kinetic machine (M), according to the claim 1, wherein there is only one turbine to provide low cost and high Power Coefficient.

7. The modular kinetic machine (M), according to claim 1, wherein the one or more turbines are a plurality of turbines installed on a single fixture, including a number of floating/axes control devices.

8.-9. (canceled)

Description

BRIEF DESCRIPTION OF DRAWINGS

[0032] FIG. 1 is an axonometric view displaying a machine as per invention;

[0033] FIG. 2 is an axonometric view of the external bladed turbine (T1), cross sectioned by a diametral plan perpendicular to the rotational plan;

[0034] FIG. 3 is an axonometric view of the internal bladed turbine (T2), cross sectioned by a diametral plan perpendicular to the rotational plan;

[0035] FIG. 4 is a side view of the floating/positioning system (F) of the machine;

[0036] FIG. 5 shows the more profitable purpose of anchoring of the the invention compared to the previous art;

[0037] FIG. 6 is a frontal view of the double turbine as assembled;

[0038] FIG. 7 is an axonometric view of a version of a single turbine machine (M) as per invention;

[0039] FIG. 8 is an axonometric view of the generator (G1), cross sectioned by a diametral plan perpendicular to the rotational plan, built in the turbine (T1);

[0040] FIG. 9 is an axonometric view of the generator (G21), cross sectioned by a diametral plan perpendicular to the rotational plan, built in the turbine (T2).

BEST MODE FOR CARRYING OUT THE INVENTION

[0041] The following descriptions are the minimum instructions whose an expertise person needs to build the machine, consequently any other improvements/modifications can be introduced without any preconceptions to the subject of the subject of the innovation and without vary the related field of protection as defined on the claims.

[0042] The machine of the finding, generically defined as (M) in FIG. 1, is a floating one, that is to say immersed in water but not anchored to the shore bed, just connected to the shore by a system allowing to balance the drag exerted over the machine itself by the flow.

[0043] The machine (M) following the invention consists of two coaxial turbines counter rotating, one with external blades (T1) and the other with internal blades (T2); a floating/positioning system; a connection system between machine and shore (FIG. 5 shows the working principle).

[0044] The turbine (T1), as shown in FIG. 2, consists of a rotor (R1), a stator (S1) and a synchronous generator (G1).

[0045] The rotor (R1), round shaped, is composed of four rings (1a, 1b, 1c, 1d). It rotates inside the stator (S1) housing over the external perimeter the blades (5).

[0046] The blades (5), of suitable aerodynamic shape and section and at low aspect ratio (less than two), are characterized by a tapered shape with root chord larger or equal than the tip one. The connection blade-rotor is at section with the longer chord.

[0047] The stator (S1) is a case torus shaped assembled with four rings (2a, 2b, 2c, 2d).

[0048] The generator (G1), shown in FIG. 8, consists of a metal support ring (14), housed inside the rotor (R1), where are installed a number of permanent magnets (15) and a metal support ring (16), housed inside the stator (S1), where are installed a number of copper coils (17), in the same quantity as the magnets.

[0049] The quantity of the rotor blades, the magnets and coils can vary depending on the design purpose and specifications.

[0050] The rotation of the rotor (R1) inside the stator (S1) is provided by means of rotating elements (4) of spherical, cylindrical or other suitable shape, order to reduce the mechanical friction between stator and rotor. Such elements, in variable quantity depending on the purpose and design specifications, run along circular races made partially on the rotor, near to the blades root, and partially on the stator (as shown in FIG. 2); these elements are positioned at the same mutual suitable distance by a spacer (3). As optional configuration, instead of the rotating elements, it is possible, depending on the purpose, it is possible to introduce, or use at the same time, any other devices using other physical phenomena (as example, but not the only one, the magnetic levitation), in order to reduce the friction.

[0051] The turbine (T2), as shown in FIG. 3, consists of a rotor (R2), a stator (S2) and a synchronous generator (G2).

[0052] The rotor (R2), round shaped, is composed of four rings (6a, 6b, 6c, 6d). It rotates inside the stator (S2) housing in the internal perimeter the blades (10). It rotates inside the stator (S2) housing in the internal perimeter the blades (10).

[0053] The blades (10), of suitable aerodynamic shape and section, are characterized by a tapered shape with root chord smaller or equal than the tip one. The connection blade-rotor is at section with the smaller chord.

[0054] The stator (S2) is a case torus shaped assembled with six rings (7a, 7b, 7c, 7d, 7e, 7f).

[0055] The generator (G2), shown in FIG. 9, consists of a metal support ring (18), housed inside the rotor (R2), where are installed a number of permanent magnets (19) and a metal support ring (20), housed inside the stator (S2), where are installed a number of copper coils (21), in the same quantity as the magnets.

[0056] The quantity of the rotor blades, the magnets and coils can vary depending on the design purpose and specifications.

[0057] The rotation of the rotor (R2) inside the stator (S2) is provided by means of rotating elements (9) of spherical, cylindrical or other suitable shape, order to reduce the mechanical friction between stator and rotor. Such elements, in variable quantity depending on the purpose and design specifications, run along circular races made partially on the rotor, near to the blades root, and partially on the stator (as shown in FIG. 3); these elements are positioned at the same mutual suitable distance by a spacer (8). As optional configuration, instead of the rotating elements, it is possible, depending on the purpose, it is possible to introduce, or use at the same time, any other devices using other physical phenomena (as example, but not the only one, the magnetic levitation), in order to reduce the friction.

[0058] The floating/positioning system (F), as shown in FIG. 4, consists of a floater (11), a positioning wing (12) and a fixture connecting the machine to the floater (13).

[0059] The synergic operation provided by the cited components (11) (12) e (13) allows to control the machine at the datum distance from the the water surface and shore, as per design requirements, as shown in FIG. 5.

[0060] In particular: [0061] the floater (11), suitably designed and modelled, provides the right depth of the machine and the stability during the transients in order to optimize the energy production (see: S. Barbarelli, G. Florio, M. Amelio, N. M. Scornaienchi, A. Cutrupi, G. Lo Zupone Transients analysis of a tidal currents self-balancing kinetic turbine with floating stabilizer Applied Energy 160 (2015) 715-727); [0062] the positioning wing (12) allows controlling the machine position with regard to the shore (see: Barbarelli S., Amelio M., Castiglione T., Florio G., Scornaienchi N. M., Cutrupi A., Lo Zupone G., Analysis of the equilibrium conditions of a double rotor turbine prototype designed for the exploitation of the tidal currents, Energy Conversion and Management, 2014, Vol. 87, pp. 1124-1133—doi:10.1016/j.egypro.2014.11.1005); [0063] the connecting fixture machine-floater (13) consists of one or more beams, or any other support structure useful for the purpose, and it is designed for providing the optimal machine depth, at which the maximum suitable flow speed is achieved as required from the design.

[0064] The innovative aspects of the present invention, compared to the closest prior art, are:

[0065] Modularity

[0066] Structural, mechanical and electrical turbine independency, allowing the machine to be fully modular, proves to be the machine itself more profitable in terms of components manufacturing and assembling and also maintenance. Mainly, the modularity concept provides a stop operation time reduction, to pull out one or more fault turbines meanwhile the remaining ones can continue the production even in a lower quantity.

[0067] Floating/Positioning System

[0068] The floating/positioning system (F) covers the control of the roll, pitch and yaw of the machine (M), thanks to the configuration and the innovative features of the system (F). Its configuration, as per invention, is specifically favourable because, as shown in FIG. 1, the machine (M) acts as a pendulum hinged at roll axis A′ and pitch axis B′ (depending on the considered oscillation plan); meanwhile the rotational control around the yaw axis C is performed by the floater (11) shape and by the fluid dynamics performances of the positioning wing (12). In particular: [0069] the floater volume (11), due to the volume of the moved fluid by the immersed machine, provides to avoid the machine sinks; meanwhile, the shape, due to specific fluid dynamic requirements as shown in figures only for example purpose, allows to maintain the right machine position during the small oscillations around the axes A′ and B′; [0070] the positioning wing (12), located outside the turbine, can be designed at higher aspect ratios (more than one), in order to operate with higher positioning angles and linking machine-shore fixture shorter, as shown in FIG. 5 (cfr. S. Barbarelli, G. Florio, M. Amelio, N. M. Scornaienchi, A. Cutrupi, G. Lo Zupone Transients analysis of a tidal currents self-balancing kinetic turbine with floating stabilizer Applied Energy 160 (2015) 715-727); [0071] the length “l” of the element (13), measured from the rotational axis A of the turbine, fixes the oscillation period of the machine, once known mass and momentum of inertia of the the machine itself.

[0072] Central Hole

[0073] The optimal sizing of the central hole is based on a comparative analysis performed by CFD, referring to a conventional turbine “wind like”, with central hub, a turbine open center single rotor, as per invention, and a double rotor turbine, as per invention, demonstrate that the last one is profitable in terms of energy production.

[0074] It is in fact known that the performances, in terms of energy production, depend, at same other factors, on the Power Coefficient Cp and the swept area S.

[0075] The results show that, by increasing the central hole diameter Di, as shown in FIG. 6, maintaining the external diameter De of the turbine (T1), an open center turbine provides a Cp higher than a “wind like” (with central hub). Anyway the energy production is lower, in the open center case, due to the fact that the swept area reduces when the central hole diameter increases.

[0076] A good settlement, between the advantages taken from the conventional technology and the ones offered from the open center solution, following the obtained results, is provided adopting the open center solution combined with the double rotor configuration, taking the advantages of suitable energy production of the innovative technology (as shown in Giacomo Lo Zupone, Mario Amelio, Silvio Barbarelli, Gaetano Florio, Nino Michele Scornaienchi, Antonino Cutrupi LCOE evaluation for a tidal kinetic self balancing turbine: Case study and comparison Applied Energy 185 (2017) 1292-1302), on the current invention is based.

[0077] Indeed, this solution allows to achieve, despite a lower swept area, an increase of Cp and energy production compared to the ones of the conventional technology, with more economic advantages (as shown in Giacomo Lo Zupone, Mario Amelio, Silvio Barbarelli, Gaetano Florio, Nino Michele Scornaienchi, Antonino Cutrupi LCOE evaluation for a tidal kinetic self balancing turbine: Case study and comparison Applied Energy 185 (2017) 1292-1302).

[0078] It is also known that the central hole solution reduces the fauna impact and, as demonstrated by the CFD results, the wake phenomena, behind the machine, are significantly reduced.

[0079] FIG. 7 depicts one more example of practical execution of the invention involving the principle just displayed. A single turbine configuration is more performing, in terms of Power Coefficient Cp, compared to the double rotor configuration previously considered, and so it is a profitable solution for low cost purposes and/or small users.

[0080] Such a solution is mostly profitable for some purposes requiring a number of installed turbines on the same anchoring structure, including floating/positioning systems custom designed.

SEQUENCE LISTING PART OF THE DESCRIPTION

[0081] M machine [0082] T1 turbine: external bladed [0083] T2 turbine: internal bladed [0084] F floating/positioning system [0085] A turbine rotational axis [0086] B turbine pitch axis [0087] C yaw axis [0088] A′ machine roll axis [0089] B′ machine pitch axis [0090] 1 machine—floater lenght fixture [0091] R1 rotor 1 [0092] 1a ring 1 [0093] 1b ring 2 [0094] 1c ring 3 [0095] 1d ring 4 [0096] S1 stator 1 [0097] 2a ring 1 [0098] 2b ring 2 [0099] 2c ring 3 [0100] 2d ring 4 [0101] 3 balls spacer [0102] 4 balls [0103] 5 blades [0104] G1 external bladed turbine generator [0105] 14 generator rotor ring [0106] 15 magnet [0107] 16 generator stator ring [0108] 17 coil [0109] R2 rotor 2 [0110] 6a ring 1 [0111] 6b ring 2 [0112] 6c ring 3 [0113] 6d ring 4 [0114] S2 stator 2 [0115] 7a ring 1 [0116] 7b ring 2 [0117] 7c ring 3 [0118] 7d ring 4 [0119] 7e ring 5 [0120] 7f ring 6 [0121] 8 balls spacer [0122] 9 balls [0123] 10 blades [0124] G2 internal bladed turbine generator [0125] 18 generator rotor ring [0126] 19 magnet [0127] 20 generator stator ring [0128] 21 coil [0129] 11 floater [0130] 12 positioning wing [0131] 13 fixture link machine-floater [0132] 22 prior art [0133] 23 new finding subject of present invention [0134] 24 anchoring element length of prior art [0135] 25 anchoring element length of new finding [0136] 26 anchoring base [0137] 27 boundary layer [0138] 28 shore [0139] Di internal turbine diameter [0140] De external turbine diameter