1. An optical fiber, comprising:
a fiber core having a radial thickness;
a cladding layer enclosing the fiber core having a radial thickness half of the radial thickness of the fiber core;
a first buffering layer attached to the cladding layer having a radial thickness equal to the radial thickness of the fiber core;
a colored layer coating on the first buffering layer, the colored layer being made of color ink or paint;
a second buffering layer enclosing the colored layer having a radial thickness twice of the radial thickness of the first buffering layer; and
wherein the second buffering layer is at least partially transparent or translucent and the colored layer can be observed from an outside.
2. The optical fiber as recited in claim 1, wherein the fiber core is cylindrical shape and made of quartz glass.
3. The optical fiber as recited in claim 2, wherein a diameter of the fiber core is about 62.5 um.
4. The optical fiber as recited in claim 1, wherein the fiber core, the clapping layer, the first buffering layer, the colored layer, the second buffering layer are coaxially arranged from an inner to an outside.
5. The optical fiber as recited in claim 4, wherein the cladding layer has a radial thickness about 31.25 um.
6. The optical fiber as recited in claim 4, wherein the first buffering layer has a radial thickness about 62.5 um.
7. The optical fiber as recited in claim 4, wherein the second buffering layer has a radial thickness about 122.5 um.
8. The optical fiber as recited in claim 4, wherein the colored layer has a radial thickness about 2.5 um.
9. The optical fiber as recited in claim 1, wherein both the first buffering layer and the second buffering layer are made of resin.
10. An optical fiber, comprising:
a fiber core;
a cladding layer enclosing the fiber core;
a first buffering layer attached to the cladding layer;
a colored layer coating on the first buffering layer, the colored layer being made of color ink or paint;
a second buffering layer enclosing the colored layer; and
wherein the first buffering layer and the second buffering layer are at least partially transparent or translucent and separated from each other by the colored layer, under the condition that portions of the first buffering layer and the second buffering layer facilitating stripping off, respectively;
wherein the second buffering layer is about twice thickness of the first buffering layer;
wherein the fiber core is circular shape and has a diameter twice of a radial thickness of the cladding layer.
11. The optical fiber as recited in claim 10, wherein the colored layer is much thinner than the first and the second buffering layers, that the colored layer is more fragile than the first buffering layer and the second buffering layer.
12. The optical fiber as recited in claim 10, wherein the both the fiber core and the cladding layer are made of glass.
13. An optical fiber comprising:
a core, a cladding layer, an inner buffering layer, an identification layer and an outer buffering layer coaxially surrounding one another in sequence wherein at least a part of the outer buffering layer is translucent or transparent for allowing the identification layer to be visible from an exterior; wherein
said identification layer is essentially not of strength material and a thickness of said identification layer is dimensioned to be less than one tenth of those of both said inner buffering layer and said outer buffering layer.
14. The optical fiber as claimed in claim 13, wherein a thickness of said identification layer is less than 10 um.
15. The optical fiber as claimed in claim 13, wherein said thickness of the identification layer is 2.5 um.
16. The optical fiber as claimed in claim 13, wherein said identification layer is coated or printed upon the cladding layer and thinner than both the core and the cladding layer.
17. The optical fiber as claimed in claim 13, wherein said identification layer is colored.
18. The optical fiber as claimed in claim 13, wherein the inner buffering layer and the outer buffering layer are essentially axially completely separated from each other by said identification layer.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A generating apparatus for converting kinetic energy from a substantially horizontal water flow to electrical energy, the apparatus comprising:
a rotationally fixed hub;
a power wheel arranged for rotation about a substantially vertical axis about the hub and provided with rotor vanes adapted to cause rotation of the power wheel when the power wheel is subject to a substantially horizontal water flow;
a shroud rotationally mounted on the hub and arranged to cover at least some of the rotor vanes of the power wheel;
a directional controller adapted to hold the shroud in a predetermined rotational position relative to the hub dependent on the direction of the substantially horizontal water flow; and
at least one generator provided on the hub and adapted to produce electrical power output derived from rotation of the power wheel relative to the hub.
2. A generating apparatus according to claim 1, wherein the power wheel and the shroud each have controlled buoyancy.
3. A generating apparatus according to claim 1 or 2, wherein the shroud extends over at least 180\xb0 and substantially covers at least half of the rotor vanes of the power wheel at any instant.
4. A generating apparatus according to any of claims 1 or 3, wherein the shroud substantially covers at least some of the rotor vanes moving in a direction opposed to the direction of the substantially horizontal water flow.
5. A generating apparatus according to any of claims 1 to 4, wherein the shroud includes a plurality of vertically extending apertures adjacent to rotor vanes moving in a direction opposed to the direction of the substantially horizontal water flow.
6. A generating apparatus according to any of claims 1 to 5, wherein the shroud includes a plurality of shroud vanes adapted to divert water flow away from the vertical axis.
7. A generating apparatus according to claim 6, wherein the shroud vanes are adapted to create regions of low pressure adjacent to at least some of the rotor vanes moving in a direction opposed to the direction of the substantially horizontal water flow.
8. A generating apparatus according to any of claims 1 to 7, wherein the directional controller comprises a directional vane connected to the shroud and extending radially away from the shroud.
9. A generating apparatus according to claim 8, wherein the directional vane includes a trimming device adapted to trim the rotational position of the shroud.
10. A generating apparatus according to any of claims 8 to 9, wherein the directional controller comprises a flow separator connected to the shroud radially in a location substantially diametrically opposite the directional vane, the flow separator being shaped so as to divert at least part of the substantially horizontal water flow onto the rotor vanes of the power wheel.
11. A generating apparatus according to any of claims 1 to 10, further including:
a support structure to which the hub is rotationally fixed to the support structure; and
a hub level controller adapted to control the level of the hub on the support structure.
12. A generating apparatus according to claim 11, wherein the support structure comprises a substantially vertical support column.
13. A generating apparatus according to any of claims 11 to 12, wherein the support structure comprises one or more guide means which engage with one or more key means on the hub to prevent relative rotation of the support structure and hub.
14. A generating apparatus according to any of claims 11 to 13, wherein the hub level controller comprises one or more floodable ballast chambers provided on the hub.
15. A generating apparatus according to any of claims 1 to 14, wherein each generator is provided in a generator chamber having an opening in a roof of said generator chamber and a removable cover sealably covering said opening.
16. A generating apparatus according to claim 15 when dependent on claim 11, further including a crane provided on the support structure and adapted to lift any one of said generators.
17. A generating apparatus according to any of claims 1 to 16, wherein the apparatus includes a plurality of hydraulic pumps provided on the hub, each hydraulic pump being adapted to pump hydraulic fluid to drive one or more of said generators.
18. A generating apparatus according to claim 17, wherein each hydraulic pump is provided in a pump chamber having an opening in a roof of said pump chamber, each hydraulic pump being liftable through said opening.
19. A generating apparatus according to any of claims 1 to 18, wherein the apparatus includes a plurality of transmissions provided on the hub, each transmission being adapted to transmit a driving force from the power wheel to drive one or more generators.
20. A generating apparatus according to any of claims 1 to 19, wherein the generating apparatus comprises a substantially vertical support column and a plurality of hubs, each hub being rotationally fixed to the support column, and each hub having an associated power wheel arranged for rotation about a substantially vertical axis about the hub and provided with rotor vanes adapted to cause rotation of the power wheel when the power wheel is subject to a substantially horizontal water flow to drive one or more generators provided on the hub.
21. A generating apparatus according to any of claims 1 to 20, the apparatus further comprising:
a plurality of generators provided on the hub and adapted to produce electrical power output derived from rotation of the power wheel relative to the hub, each generator having an associated drive means driven by rotation of the power wheel; and
generator control means adapted to selectively switch each of said plurality of generators between an active state and an inactive state.
22. A generating apparatus according to claim 21, wherein the generator control means includes an electrical controller adapted to selectively switch each of said plurality of generators on and off.
23. A generating apparatus according to claim 21 or 22, wherein the generator control means includes a sensor for detecting a speed parameter indicative of the relative rotational speed of the power wheel and the hub.
24. A generating apparatus according to any of claims 21 to 23, wherein the generator control means includes switching means adapted to switch each of said plurality of generators between an active state and an inactive state in response to the detected speed parameter.
25. A generating apparatus according to claim 24, wherein the generator control means is adapted to switch more generators to an active state when the detected speed parameter is indicative of an increase in the relative rotational speed of the power wheel and the hub.
26. A generating apparatus according to any of claims 24 to 25, wherein the generator control means is adapted to switch a generator to an active state when the detected speed parameter is indicative that the relative rotational speed of the power wheel and the hub has reached a predetermined upper trigger value.
27. A generating apparatus according to any of claims 24 to 26, wherein the generator control means is adapted to switch a generator to an inactive state when the detected speed parameter is indicative that the relative rotational speed of the power wheel and the hub has reached a predetermined lower trigger value.
28. A generating apparatus according to any of claims 21 to 27, wherein each drive means comprises:
a primary driver driven by the power wheel;
a drive shaft for driving the associated generator; and
a transmission coupled between the primary driver and the drive shaft.
29. A generating apparatus according to claim 27, wherein the apparatus includes a primary transmission comprising a ring gear fixed to the power wheel and adapted to drive each of the primary drivers.
30. A generating apparatus according to claim 28 or 29, wherein each drive means includes a clutch to selectively engage or disengage the generator from the drive shaft.
31. A generating apparatus according to any of claims 21 to 27, wherein each drive means comprises:
a hydraulic pump provided on the hub, the hydraulic pump being adapted to pump hydraulic fluid;
a primary transmission coupled between the power wheel and the hydraulic pump;
a hydraulic motor associated with the generator; and
hydraulic control means adapted to direct flow of the hydraulic fluid to the hydraulic motor.
32. A generating apparatus according to claim 31, wherein the primary transmission comprises a ring gear fixed to the power wheel and a plurality of pinions, each pinion being coupled by a drive shaft to one of said hydraulic pumps.
33. A generating apparatus according to claim 31 or 32, wherein the hydraulic control means includes a sensor for detecting a speed parameter indicative of the relative rotational speed of the power wheel and the hub.
34. A generating apparatus according to claim 33, wherein the hydraulic control means includes valve switching means adapted to direct flow of said hydraulic fluid to one or more of said hydraulic motors in response to the detected speed parameter.
35. A method of generating electricity from a substantially horizontal water flow in a body of water using a generating apparatus including a power wheel arranged for rotation about a substantially vertical axis about a hub rotationally fixed to a support structure, the power wheel having a plurality of rotor vanes, the method comprising the steps of:
providing a shroud rotationally mounted on the hub and arranged to cover at least some of the rotor vanes of the power wheel;
fixing the hub in an operating position in the substantially horizontal water flow;
aligning the shroud with the substantially horizontal water flow such that the rotor vanes on a first side of the generating apparatus are not covered by the shroud and are subject to hydrodynamic forces from the substantially horizontal water flow, and such that the rotor vanes on a second side of the generating apparatus are at least partially covered by the shroud so as to at least partially shield the rotor vanes from hydrodynamic forces from the substantially horizontal water flow;
driving the power wheel to rotate about the hub by means of the hydrodynamic forces from the substantially horizontal water flow on the rotor vanes provided on the power wheel; and
driving one or more generators provided on the hub from the rotation of the power wheel.
36. A method according to claim 35, wherein the step of aligning the shroud is carried out by providing a directional controller on the shroud adapted to hold the shroud in a predetermined rotational position relative to the hub dependent on the direction of the substantially horizontal water flow.
37. A method according to claim 35 or 36, wherein the directional controller comprises a directional vane connected to the shroud and extending radially away from the shroud, and the step of aligning the shroud includes allowing the shroud to adopt an equilibrium position such that the directional vane is substantially aligned with the substantially horizontal water flow.
38. A method according to any of claims 35 to 37, wherein the step of aligning the shroud includes the further step of trimming the rotational position of the shroud, for example by adjusting the position of a pivotable flange, for example a trim tab or servo tab, at the trailing edge of the directional vane.
39. A method according to any of claims 35 to 38, including the further step of separating the substantially horizontal water flow at the generating apparatus so as to divert at least part of the substantially horizontal water flow onto the rotor vanes of the power wheel on the first side of the generating apparatus and to divert at least part of the substantially horizontal water flow past the shroud on the second side of the generating apparatus.
40. A method according to claim 39, wherein the separating step is carried out by a flow separator connected to the shroud radially in a location substantially diametrically opposite the directional vane.
41. A method according to any of claims 35 to 40, including the
step of providing a plurality of vertically extending apertures adjacent to rotor vanes moving in a direction opposed to the direction of the substantially horizontal water flow and creating a region of reduced pressure adjacent to at least some of the plurality of vertically extending apertures.
42. A method according to any of claims 35 to 41, including the
step of providing a plurality of shroud vanes and creating regions of low pressure adjacent to at least some of the rotor vanes moving in a direction opposed to the direction of the substantially horizontal water flow.
43. A method according to any of claims 35 to 42, comprising the further step of:
moving the hub in a vertical direction on the support structure to an operating position in the substantially horizontal water flow.
44. A method according to claim 43, further including the step of selecting an optimum level in the substantially horizontal water flow and moving the hub in a vertical direction on the support structure to an operating position at said level.
45. A method according to any of claims 43 to 44, wherein the step of moving the hub to an operating position includes flooding one or more floodable ballast chambers provided on the hub.
46. A method according to any of claims 43 to 45, further including the step of lifting the hub in a vertical direction on the support structure to a maintenance position in which at least part of the generating apparatus is above the surface of the body of water.
47. A method according to claim 46, wherein the step of lifting the hub to a maintenance position includes displacing water from one or more floodable ballast chambers provided on the hub.
48. A method according to any of claims 35 to 42, comprising the steps of:
driving a plurality of drive means from the rotation of the power wheel to pump pressurised hydraulic fluid, each drive means being associated with one of a plurality of generators on the hub;
selectively switching each of said plurality of generators between an active state in which the generator is driven by the associated drive means to generate electrical power and an inactive state in which the generator generates no electrical power; and
generating electrical power from the plurality of generators.
49. A method according to claim 48, wherein the step of driving a plurality of drive means includes:
driving a plurality of pumps from the rotation of the power wheel to pump pressurised hydraulic fluid; and
selectively directing the pressurised hydraulic fluid to one or more of a plurality of hydraulic motors, each hydraulic motor being associated with one of a plurality of generators on the hub.
50. A method according to claim 49, wherein the step of driving a plurality of pumps includes driving a plurality of pinions from a ring gear fixed to the power wheel, each pinion being coupled by a drive shaft to one of said hydraulic pumps.
51. A method according to any of claims 48 to 50, wherein the method includes the step of detecting a rotational speed parameter indicative of the relative rotational speed of the power wheel and the hub.
52. A method according claim 51, wherein the method includes the step of detecting a flow speed parameter indicative of the speed of the substantially horizontal water flow.
53. A method according claim 52, wherein the method of selectively switching each of said plurality of generators between an active state and an inactive state includes selecting a number of generators to be switched to the active state based on one or both of the detected rotational speed parameter and the detected flow speed parameter.
54. A method according to any of claims 51 to 53, wherein the step of selectively switching each of said plurality of generators between an active state and an inactive state includes selecting more generators to be switched to the active state when one or more of the detected speed parameters is indicative of an increase in the relative rotational speed of the power wheel and the hub or an increase in the speed of the substantially horizontal water flow.
55. A method according to any of claims 51 to 54, wherein the step of selectively switching each of said plurality of generators between an active state and an inactive state includes selecting fewer generators to be switched to the active state when the detected speed parameter is indicative of a decrease in the relative rotational speed of the power wheel and the hub or a decrease in the speed of the substantially horizontal water flow.
56. A method according to any of claims 35 to 55, wherein the generating apparatus is a generating apparatus according to any of claims 1 to 34.