A MULTIROTOR WIND TURBINE

Abstract

A multirotor wind turbine (1) comprising a vertical tower and at least two energy generating units (5), a load carrying structure (9, 10) extending transverse to the vertical direction and carrying the at least two energy generating units (5); and at least one escape route extending between a start and an exit. To provide a safe escape route, the load carrying structure forms at least a first section of the escape route from the start to an intermediate location, and the wind turbine comprises an escape opening in the nacelle, the escape opening leading from an interior space of a nacelle of the energy generating unit to a passage structure and the passage structure extending from the escape opening to the start of the escape route.

Claims

1. A multirotor wind turbine comprising: a tower extending in a vertical direction from a tower bottom to a tower top (4); at least two energy generating units, each energy generating unit holding a rotor arranged to rotate a drive train and each energy generating unit comprising a nacelle forming an interior space for the drive train; a load carrying structure extending transverse to the vertical direction and carried by the tower, the load carrying structure arranged to carry the at least two energy generating units; and at least one escape route extending between a start and an exit; wherein the load carrying structure forms at least a first section of the escape route from the start to an intermediate location, and wherein the wind turbine further comprises an escape opening in the nacelle, the escape opening leading from the interior space to a passage structure and the passage structure extending from the escape opening to the start of the escape route.

2. The multirotor wind turbine according to claim 1, wherein the nacelle forms a sidewall extending between a bottom and a roof, and wherein the escape opening is in the roof and the passage structure extends from the roof along the sidewall.

3. The multirotor wind turbine according to claim 2, wherein the roof has a forward half portion towards the rotor and a rearward half portion away from the rotor, and wherein the escape opening is in the forward half portion of the roof.

4. The multirotor wind turbine according to claim 1, wherein the nacelle forms a sidewall extending between a bottom and a roof, wherein the escape opening is in the sidewall and the passage structure extends from the escape opening along the sidewall.

5. The multirotor wind turbine according to claim 1, wherein the nacelle forms a sidewall extending between a bottom and a roof, and wherein the escape opening is in the bottom and the passage structure extends from the bottom along the sidewall.

6. The multirotor wind turbine according to claim 1, wherein the nacelle forms a sidewall extending between a bottom and a roof, and wherein the escape opening is in the sidewall, and the passage structure is constituted by a pick-up platform outside the nacelle and located at the opening to allow entrance from the nacelle to the safety platform.

7. The multirotor wind turbine according to claim 1, wherein the escape opening is in the bottom, and the passage structure is constituted by a pick-up platform below the nacelle and located at the opening to allow access to the start of the escape route from the nacelle via the opening in the bottom.

8. The multirotor wind turbine according to claim 1, wherein the load carrying structure comprises: a first load carrying arrangement extending outwards on a left side of the tower; and a second load carrying arrangement extending outwards on a right side of the tower; each load carrying arrangement comprising a primary structure attached to the tower in a lower interface and extending between the lower interface and a corresponding one of the at least two energy generating units and a tension arrangement, the tension arrangement comprising at least one secondary structure attached to the tower in an upper interface and extending above the primary structure between the upper interface and the corresponding one of the at least two energy generating units such that gravity acting on the energy generating units causes compression of the primary structure and tension in the at least one secondary structure.

9. The multirotor wind turbine according to claim 8, wherein the escape route extends along a selected one of the secondary structures.

10. The multirotor wind turbine according to claim 9, wherein the escape route includes a trolley structure movable along the selected secondary structure.

11. The multirotor wind turbine according to claim 8, wherein the tension arrangement comprises: a forward secondary structure attached to the tower in a forward point of the upper interface and extending above the primary structure between the forward point and the corresponding one of the at least two energy generating units, and a rearward secondary structure attached to the tower in a rearward point of the upper interface and extending above the primary structure between the rearward point and the corresponding one of the at least two energy generating units, where the forward point and the rearward point are on opposite sides of the right side or left side of the tower, where the forward point is closer to the rotor than the rearward point, and where the selected secondary structure extends to the rearward point.

12. The multirotor wind turbine according to claim 1, further comprising a safety platform, where the safety platform is carried at the tower top, and where the safety platform forms the exit.

13. The multirotor wind turbine according to claim 8, wherein the primary structure comprises a primary structure opening at the start, the primary structure opening configured for entrance of personnel into an internal primary structure passage extending inside the primary structure, and wherein the escape route extends through the primary structure opening and through the internal primary structure passage.

14. The multirotor wind turbine according to claim 13, comprising a fire-bulkhead arranged in the internal primary structure passage and separating the internal primary structure passage into a forward portion and a rearward portion, the forward portion extending below one of the at least two energy generating units and the rearward portion extending from the fire-bulkhead to the tower.

15. The multirotor wind turbine according to claim 14, wherein the rearward portion extends into an internal tower passage extending inside the tower from the tower top to the tower bottom.

16. The multirotor wind turbine according to claim 13, wherein the primary structure opening extends into the rearward portion.

17. The multirotor wind turbine according to claim 1, comprising at least two escape routes.

18. The multirotor wind turbine according to claim 1, comprising an electronic escape control system comprising at least one alert sensor configured to provide an alert signal upon detection of smoke, high temperatures, or loud noise.

19. The multirotor wind turbine according to claims 17, wherein the electronic escape control system comprises a processor and a number of alert sensors each configured to provide an alert signal upon detection of smoke, high temperatures, or loud noise, the alert sensors being located in different escape routes and wherein the processor is configured to communicate with the plurality of alert sensors and to select a recommended escape route between the at least two escape routes based on at least one alert signal from at least one of the alert sensors.

20. A method for escaping from a power generating unit of a multirotor wind turbine according to claim 1, wherein the power generating unit is evacuated via an escape route extending through the escape opening and via the passage structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0086] The invention will now be described in further detail with reference to the accompanying drawings in which

[0087] FIG. 1 is a front view of a multirotor wind turbine comprising two load carrying structures according to an embodiment of the invention,

[0088] FIG. 2 is an enlarged view of one of the energy generating units in FIG. 1 including further details,

[0089] FIG. 3 is a perspective view of one of the energy generating units,

[0090] FIG. 4 illustrates an escaping person using a trolley along a secondary structure,

[0091] FIG. 5 illustrates details of a safety platform at which two different escape routes terminate,

[0092] FIG. 6 outlines the contour of a wind turbine with different escape routes,

[0093] FIG. 7 illustrates a specific embodiment of the passage structure in the form of a pick-up platform connecting an opening in the nacelle with an opening in the primary structure, and

[0094] FIGS. 8 and 9 illustrate details of asymmetry between the tower cross section and the safety platform.

DETAI LED DESCRI PTI ON OF THE DRAWINGS

[0095] FIG. 1 is a front view of a multirotor wind turbine 1 comprising a tower 2 carrying two load carrying structures 3 according to an embodiment of the invention. The load carrying structures 3 are arranged one above the other, along the length of the tower 2.

[0096] Each load carrying structure 3 comprises two load carrying arrangements 4, extending away from the tower 2 on opposite sides of the tower 2, as seen from the viewing angle of FIG. 1. Each load carrying arrangement 4 carries an energy generating unit 5, and each energy generating unit 5 comprises a nacelle 6 and a rotor 7 carrying three wind turbine blades 8.

[0097] Each load carrying arrangement 4 comprises a primary structure 9, in the form of a tube, and two secondary structures 10, in the form of double wires. In FIG. 1, only one of the secondary structures 10 for each load carrying arrangement 4 is visible.

[0098] The primary structures 9 extend away from the tower 2 along a direction which forms an acute angle with respect to a substantially vertical longitudinal axis defined by the tower 2. Thereby the primary structures 9 extend away from the tower 2 along an inclined upwards direction.

[0099] The secondary structures 10 extend away from the tower 2 along a direction which is substantially perpendicular to the substantially vertical longitudinal axis defined by the tower 2. Thereby the secondary structures 10 extend away from the tower 2 along a substantially horizontal direction. Accordingly, an angle is defined between the direction in which primary structure 9 of a given load carrying arrangement 4 extends, and the plane in which the secondary structures 10 of the load carrying arrangement 4 extend.

[0100] The primary structures 9 and the secondary structures 10 are attached to the tower 2 via a yaw arrangement 11, allowing the entire load carrying structure 3 to perform yawing movements with respect to the tower 2 in order to direct the rotors 7 into the incoming wind. The yaw arrangement comprises a yaw bearing in the form of a tubular element 11′ which is arranged rotationally relative to the tower, and which encircles the outer surface of a part of the tower. The yaw arrangement 11 forms a lower and an upper interface 11″ where the load carrying structure interfaces the tower. In this way, the load carrying structure is allowed to rotate relative to the tower. The escape route may intersect a space formed between the outer surface of the tower and the tubular element 11′. For that purpose, the tubular element 11′ forms an opening allowing passage of personnel from the primary structure 9 into the tower.

[0101] The multirotor wind turbine further comprising a safety platform 12 forming an upwards facing plane working surface

[0102] The primary structures 9 of a given load carrying structure 3 and the secondary structures 10 of the load carrying structure 3 are attached to the tower 2 at separate positions along the length of the tower 2.

[0103] When gravity acts on the energy generating units 5, the mutual positions of the primary structures 9 and the secondary structures 10 causes push in the primary structures 9 and pull in the secondary structures 10. Thereby a preload is introduced in the secondary structures 10, due to the gravity acting on the energy generating units 5.

[0104] During operation of the multirotor wind turbine 1, thrust forces will act on the energy generating units 5, in the direction of the incoming wind or in the opposite direction. When this occurs, the pull in one of the secondary structures 10 of each of the load carrying arrangements 4 is decreased while the pull in the other secondary structure 10 is increased. However, the preload introduced in the secondary structures 10, due to gravity acting on the energy generating units 5, is sufficiently high to ensure that the secondary structure 10, in which the pull is decreased, remains tight. Accordingly, the load carrying structure 1 is capable of handling the thrust forces introduced during operation of the multirotor wind turbine 1.

[0105] The wind turbine illustrated in FIG. 1 forms three different escape routes. All three escape routes extend from the nacelle 6 through an escape opening in the roof of the nacelle, along a passage structure along the sidewall to a pick-up platform 13 at the primary structure.

[0106] From the pick-up platform, a first one of the three escape routes extends through a primary structure opening configured for entrance of personnel into an internal primary structure passage extending inside the primary structure. The internal primary structure passage communicates with an internal tower passage and allows escape through the tower to the safety platform 12 or to the tower bottom 2′.

[0107] From the pick-up platform, a second one of the three escape routes extends through on the primary structure, but outside the primary structure along an outer passage protected by the fence 14. This is only illustrated on one of the primary structures, but it could be implemented on all primary structures. From the outer passage, the personnel may enter the internal tower passage via a hatch in the tower and escape through the tower to the safety platform 12 or to the tower bottom 2′.

[0108] From the pick-up platform, a third one of the three escape routes extends through along one of the secondary structures 10. If one of the lower energy generating units is escaped, the personnel may enter from the secondary structure into the internal tower passage via a hatch in the tower and escape through the tower to the safety platform 12 or to the tower bottom 2′. If one of the upper energy generating units is escaped, the personnel may enter from the secondary structure directly onto the safety platform 12, or optionally, the personnel may continue from the safety platform 12 through the internal tower passage to the tower bottom 2′.

[0109] FIG. 2 illustrates an enlarged view of one of the energy generating units 5 carried by a first load carrying arrangement 9, 10. In this view, the dotted linel5 illustrates a first escape route along one of the secondary structures by use of a trolley movable directly between the energy generating unit 5 and the safety platform 12. The dotted line 16 illustrates a second escape route along the outer surface of the primary structure 9 to a hatch opening in the tower. The hatch opening allows entrance into the internal tower passage through which the escaping person can move upwardly to the safety platform 12 or downwardly to the tower bottom 2′. The dotted line 17 illustrates a passage through the internal primary structure passage from a primary structure opening at the energy generating unit down to the tower, and into the internal tower passage.

[0110] FIG. 3 illustrates an enlarged view of one of the energy generating units 5, including the escape opening 18 in the roof of the nacelle 19, and the passage structure 20 extending along the sidewall to a pick-up platform 21. The nacelle includes another escape opening 18′ in a sidewall. This escape opening allows sideways exit from the nacelle and escape along the passage structure 20 to the start of the escape route.

[0111] FIG. 3 further illustrates a primary structure opening 22 leading into an internal primary structure passage extending inside the primary structure and being connected to the internal tower passage.

[0112] Each load carrying arrangement 4 comprises two secondary structures 10′, 10″, extending on opposite sides of the primary structure 9 from the energy generating unit 5 to respective attachment points at the tower top 2″. 8. I.e. the wind turbine comprises a forward secondary structure 10′ attached to the tower in a forward point of the upper interface and extending above the primary structure 9 between the forward point and the corresponding one of the at least two energy generating units 5, and a rearward secondary structure 10″ attached to the tower in a rearward point of the upper interface and extending above the primary structure 9 between the rearward point and the corresponding one of the at least two energy generating units 5. The forward point and the rearward point are on opposite sides of the right side or left side of the tower, and the forward point is closer to the rotor than the rearward point. In this embodiment, the selected secondary structure which is used for the escape route extends to the rearward point. This is illustrated in FIG. 4, where the rearward secondary structure 10″ is used in combination with a trolley attached to a person 23 escaping from the pick-up platform 21.

[0113] FIG. 5 illustrates further details of a portion of two different escape routes. One of the escape routes extends through the internal tower passage to a tower top opening 25 into an access bridge 26. The tower top opening 25 allows entrance from the tower to the access bridge 26, and from the access bridge, the escaping person can enter the working surface 27 of the safety platform 28 where the escape can be completed by helicopter. Another of the two routes extends via one of the secondary structures 10 directly onto the working surface 27 of the safety platform 28 by use of the trolley 24 shown in FIG. 4.

[0114] FIG. 6 outlines the contour of a wind turbine where the nacelle is tubular. The arrow 29 illustrates the location of the passage structure from the escape opening at the open hatch 30 to the pick-up platform 31 forming the start of the escape route, and the arrows 32, 33, 34, 35 indicate four different escape routes, where routes 32, 34 have an exit at the tower top 2″, and routes 33, 35 have an exit at the tower bottom 2′.

[0115] FIG. 7 illustrates an embodiment where the escape opening 36 is in the bottom 37, i.e. in the floor of the nacelle 38. The passage structure is constituted by the pick-up platform 39 which is located below the nacelle directly beneath the opening 36.

[0116] In the illustrated embodiment, the load carrying structure comprises a primary structure 40 configured to absorb compression. In practise, the primary structure could be a tubular element of steel etc.

[0117] The primary structure comprises a primary structure opening 41 which defines the start of the escape route. The primary structure opening is sized to allow entrance of personnel into an internal primary structure passage extending inside the primary structure from the start to an intermediate location being at the tower. At the tower, the escape route extends through a yaw bearing and into the tower, and via an internal tower passage to the top or bottom of the tower.

[0118] A fire-bulkhead 42 is arranged in the internal primary structure passage between the nacelle and the primary structure opening 41. The bulkhead separates the internal primary structure passage and defines a rearward portion extending from the fire-bulkhead to the tower. This part is separated from fire which may occur in the nacelle.

[0119] Personnel are allowed to exit the nacelle through the opening and access the pick-up platform, and to reach the start of the escape route from the pick-up platform.

[0120] The wind turbine may additionally comprise secondary structures extending from the end of the primary structure where the energy generating unit is attached.

[0121] The secondary structures extend to a point at the tower, e.g. near the top of the tower.

[0122] The secondary structures may be configured for tension, and in practise they could be constituted by rods or cables, e.g. steel wires.

[0123] The escape route may include a well defined path along one or more of the secondary structures. The escape route may e.g. be well defined by the inclusion of a trolley structure movable along one or more of the secondary structures.

[0124] FIGS. 8 and 9 illustrate details of asymmetry between the tower cross section and the safety platform. Both FIG. 8 and FIG. 9 illustrate the wind turbine seen from above and FIG. 8 illustrates an embodiment where the contour of the safety platform 12 overlaps the contour of the tower top 2″. FIG. 9 illustrates an embodiment where the contour of the safety platform 12 does not overlap the contour of the tower top 2″.

[0125] The illustrated wind turbine has blades forming a rotor plane 43 by rotation of blades around the rotor axes 44, and in both embodiments the safety platform 12 is asymmetric in the direction away from the rotor planes 43, and in both embodiments, the platform 12 is completely within the borders defined on right and left sides by the rotor axis 44.

[0126] The safety platform 12 is asymmetric relative to the tower top 2″ which means that the geometrical centre of the safety platform 12 is shifted relative to the geometric centre of the cross section of the tower top.

[0127] In both FIGS. 8 and 9, a front point 45 of the outer periphery of the safety platform 12 is behind the corresponding front point 46 of the periphery of the tower top cross section in the direction of the arrow 47, i.e. in the direction from the rotor plane 43 along the rotor axes 44 and rearwards. The distance between the front points 45 and 46 in the direction of the arrow 47 could be anything above zero such as 10, 20, 30, 40, 50, 60 or more percent of the largest dimension of the platform.

[0128] An opposite asymmetry can also be applied, i.e. instead of the front point 45 of the outer periphery of the safety platform 12 being behind the corresponding front point 46 of the periphery of the tower top cross section in the direction of the arrow 47, the front point 45 of the outer periphery of the safety platform 12 is in front of the corresponding front point 46 of the periphery of the tower top cross section in the direction opposite the arrow 47. Again, the distance between the front points 45 and 46 in the direction opposite the arrow 47 could be anything above zero such as 10, 20, 30, 40, 50, 60 or more percent of the largest dimension of the platform.