DK179742B1

DK179742B1 - Aeration and Water-Air separation System for a Wind Turbine Generator

Info

Publication number: DK179742B1
Application number: DKPA201770792A
Authority: DK
Inventors: Hjort Søren; Kilian Allan; Kurt Christensen Claus; Ditlev Christensen Jørgen; Kjaer Ole
Original assignee: Envision Energy (Denmark) Aps
Priority date: 2017-10-18
Filing date: 2017-10-18
Publication date: 2019-05-01
Also published as: CN111279074A; CN111279074B; WO2019076414A1; DK201770792A1

Abstract

The present invention relates to an aeration or water-air separation system for a wind turbine having a wind turbine hub supporting blades and about a rotation axis rotatably arranged on a nacelle. The wind turbine hub is protected by a spinner separating an exterior from an interior and arranged to rotate with the wind turbine hub. The system has an inlet in the spinner and an outlet in the interior of the wind turbine generator.

Description

Aeration and Water-Air Separation System for a Wind Turbine Generator

Field of the Invention

The present invention relates to an aeration or water-air separation system for a wind turbine having a wind turbine hub supporting blades arranged for rotating about a rotation axis supported by a nacelle. The wind turbine hub is protected by a spinner separating an exterior from an interior and arranged to rotate with the wind turbine hub. The system has an inlet in the spinner and an outlet in the interior of the wind turbine generator.

Background of the Invention

The increasing size of modern wind turbines has led to a growing awareness and focus on the thermal control of heat emitting components in the wind turbine hub and nacelle. The need for thermal control is caused by the increasing frictional heat emitted by main components such as main bearings, gearbox, generator, converter, and control/supervisory electronics. The increasing size of said main components also increases the risk of having large thermal stresses, caused by temperature differences across a main component, e.g. a main bearing unit.

The thermal control cooling air can be delivered actively by a power-unit such as a fan with/without a compressor, or passively by using natural air convection. The advantage of a charged air convection is higher cooling impact and higher cooling controllability. The advantage of passive air convection is low cost and conceptual simplicity.

A common method to separate rain from dry air in ambient air inlets is to force the air flow through a channel of multiple angled obstructing plates, or so called “baffle plates”, such that the heavier rain drops are forced out on the baffle surfaces through centrifugal forcing effects. Baffle plate separator units are often charged powerdevices, since the flow through multiple baffles is rather obstructed, with associated pressure head losses, which necessitates an active forcing of the flow.

WO 2014/020639 A1 discloses a system for aerating the interior of a horizontal axis wind turbine and relates to the same technical field and problem of aeration of the interior of a wind turbine generator.

Object of the Invention

It is an objective of the present disclosure to provide a passive and operational system and a method for aerating the interior, e.g. hub and nacelle, of a wind turbine generator.

Description of the Invention

An object is achieved by a water-air separation system for a wind turbine having a wind turbine hub supporting blades arranged for rotating about a rotation axis supported by a nacelle. The wind turbine hub is protected by a spinner separating an exterior from an interior and arranged to rotate with the wind turbine hub. The water-air separation system configured with the following features.

The spinner has spinner front face arranged on the external side to face in the yaw direction (compass heading) away from the nacelle during intended operation. The spinner front face has an inlet connecting the exterior with the interior via a channel with a channel face connecting the inlet with an outlet in the interior.

The system has a cavity having a cavity face. The cavity face may be penetrated at least once to a cavity drain.

The cavity is partially surrounding a capture body having a capture body face and being suspended in the cavity. The capture body has a capture body front face facing the inlet and with a capture body rear face extending away from the front face and facing the outlet. The capture body substantially defining a volume.

The system described enables passive aeration of the interior of a wind turbine generator in an effective way. The system further enables separation of water and air during rain, snow, hail, generally humid or alike adverse weather conditions thereby enabling aeration during otherwise adverse weather conditions.

The system described further enables passive aeration without disturbing, or with minimal impact on, the wind conditions experienced by the wind turbine during operation.

The system described even further provides, at least for a variety or broad range of wind flow conditions, a laminar air flow, a substantially laminar air flow, or a sufficiently conditioned air flow into the interior of the wind turbine.

The system disclosed further overcomes or improves prior disadvantages of passive air convection where the air mass-flow might be insufficient during operational active periods of low wind, and/or periods with high ambient temperature. The system disclosed enables or improves the convective inflow of air that enters the hub/nacelle by providing a flow channel or arrangement that is as unobstructed as possible, such that the free stream ambient wind can enter the wind turbine directly, e.g. through an orifice in the hub apex pointing directly into the upstream wind.

Instead of allowing a direct inflow of unobstructed ambient wind with the disadvantage of allowing precipitation, such as rain, snow, hail, etc. to enter the hub, the system further eliminates or reduces the introduction of water into the hub and nacelle which will accelerate corrosion processes, and increase the potential risk of electric short-circuiting.

During operation i.e. when the rotor is rotating, The disclosed system constitutes an air-rain or air-water separator for a wind turbine hub, where the rain is separated by centrifugal force in a way which minimizes the pressure head loss, such that the device will work effectively in passive mode, without the need of external power to force the flow through.

The inlet, the cavity and the capture body form the channel or canal. The faces of the respective parts may overlap but collectively form the channel having a channel face. A person skilled in the art will appreciate parts or sections and generally be able to make transitions and integrations. Having gained operational experience, a person skilled in the art will also be induced to modify or adjust relative arrangements, curvatures of faces to circumvent experienced adverse effects.

The channel face may have an outward channel face primarily formed by the inlet face and the cavity face. The channel face may have an inward channel face primarily formed by the capture body face.

In an aspect, the channel face is substantially symmetrical about a symmetry axis. The symmetry axis may be substantially aligned with the rotation axis during intended operation. Thereby rotating the channel face and substantially maintaining the channel shape relative to the flow.

Thereby, the channel face may, by design, be symmetrical about a symmetry axis. In an aspect, the system may be installed to align with the rotation axis of the rotor during operation of the wind turbine. Thus, rotating the drain will guide the water towards the outlets of the drain.

Freedom in the placement and/or actual symmetry of capture body suspension means is available. Thus, the capture body may be suspended by capture body suspension means that adhere to symmetry or the capture body suspension means may e.g. using three suspension means break the symmetry.

In an aspect, the capture body face is substantially symmetrical about a symmetry axis. The symmetry axis may be substantially aligned with the rotation axis during intended operation. Thereby, forming part of the channel face and substantially maintaining the shape relative to the flow when rotated.

The capture body front face may be substantially symmetrical about a symmetry axis. The capture body rear face may be substantially symmetrical about a symmetry axis.

A person skilled in the art will realise that there may be introduced asymmetry e.g. by attachments or connection of capture body connection means. Likewise e.g. the capture body rear side may have features that introduce asymmetry.

In an aspect guides may be arranged on the capture body. In one aspect there may be guides along the capture body front face, which guides are arranged from a foremost centre point and extend in the flow direction. Such guides may deviate from perfect symmetry.

In an aspect, the capture body has a capture body front face facing the inlet and arranged to more than cover the projection of the inlet aperture onto the capture body. The capture body has the capture body front face arranged to cover more than the extent of the inlet aperture.

Thus, from a point of view along a common symmetry axis or when installed along an axis the capture body covers the inlet aperture area. Thus, enabling capturing a majority of water during rain and stopping and radially distributing the air flow towards the face of the cavity.

In an aspect, the capture body has the capture body rear face formed with curvature that is more curved than the curvature of the capture body front face.

The capture body front face may be relatively flat albeit curved. The capture body front face is arranged at a distance from the inlet aperture and the capture body front face has a curvature so as to form a converging smooth and aerodynamically sound entry part of the channel. The capture body may be arranged in the cavity so that the capture body front face is downward from the inlet aperture. The capture body front face may be in the vicinity or crossing the inlet aperture. In an aspect the capture body may be adjustable along the axis so as to adjust the size of the inlet part of the channel and the flow characteristics; including closing of the channel or the inlet aperture.

The capture body rear face may be formed in view of the cavity to form a diverging channel part towards the outlet. The capture body rear face may also have a curvature that is more curved than the front face.

In an aspect, the capture body is arranged in the cavity where the cavity face and the capture body face are formed to converge the channel from the inlet towards a minimum channel width and from there to diverge the channel towards the outlet.

Due to the convergence the flow will accelerate and cause the flow to have a favourable pressure gradient.

Aspects hereof will be described in details in the following.

In an aspect, the channel 300 has an inlet centre flow line 320 centred between the cavity face 410 and the capture body face 510 and an outlet centre flow line 330 centred between the cavity face 410 and the capture body face 510, wherein the cavity face 410 and the capture body face 510 are formed and arranged so that the inlet centre flow line 320 and the outlet centre flow line 330 break in a turn angle 350, which turn angle 350 is at least 70-degrees. A turn angle of about 90-degrees may also be a suitable starting point. Turn angles may vary or be adjustable or differ during operation.

The outlined definition and suggested definition of a turn angle at least provides a starting point to achieve an advantageous flow pattern and separation of water and air where the inside channel surface of said channel is that of a smooth bluff body which directs the flow axis-symmetrically radially outwards and then radially inwards, such that the turn angle of the inwards curving flow, say at least 70 degrees, effects that centrifugal separation of the rain will take place.

The outward channel surface, i.e. on the cavity face, is off-set from the inside channel surface, i.e. on the capture body face, so that the channel cross-area is converging, thereby effecting that the flow will accelerate and cause the flow to have a favourable pressure gradient so that flow separation and stall is avoided. Furthermore the pressure head loss is minimized.

In an aspect, the spinner front face is substantially symmetrical about a symmetry axis and in the radial cross section having a stagnation point foremost. From the stagnation point towards the cavity the spinner has an inlet face that is aerodynamically shaped.

The stagnation point or stagnation periphery parts the wind flow in two parts. One outer part that directs the wind flow on the exterior and to pass the wind turbine as intended for producing power. Another inner part directs a part of the wind flow to the interior via the disclosed aeration or water-air separation system. The partition of the wind flow is according to the disclosure as un-disturbing as possible.

The inlet face from the stagnation point or stagnation periphery to the inlet aperture point or inlet aperture periphery forms a part of the channel face. The inlet face may be aerodynamically shaped. The area about the stagnation point or periphery may be aerodynamically shaped. The transition from the inlet face to the cavity face may also be curved, smooth or aerodynamically shaped.

Generally the system may be provided with drains for removing collected water from the system. Drains may be holes, penetrations or alike. A person skilled in the art will place the drains at gravitationally low points or valleys. Drains or holes may also be present downwards of the flow direction to capture water pressed up-hill during operation or experiencing flows.

The water from say rain will be caught on the radially outward channel surface and is led through surface holes or slits connected to a hose that drains the water away from the hub and out into the ambient surroundings or exterior.

In an aspect, the cavity drain may be penetrating the cavity face at about the maximum width, or at a gravitational low of a valley. The drain may be formed as a spiral spiralling towards the spinner inlet penetrating the spinner front face, the spiralling of the spiral being threaded as the intended rotational direction of the rotor. This should be equivalent to a right hand thread for right hand rotation. Thus rotating the drain will guide the water towards the outlets of the drain.

Hence, the rain or water content being caught on the outward channel surface is led through surface holes or slits connected to a hose or drain, which then is spiralling back towards the inlet, where the water may be disposed of. The spiralling back of the hose is arranged so that the water trapped in the lower part of the hose or drain windings will work its way back towards or upstream towards the air inlet by the rotational motion of the hub itself.

Similarly, an opposite spiralling drain may be implemented. In an aspect, the cavity drain may be penetrating the cavity face at about the maximum width, or at a gravitational low, and is formed as a spiral spiralling towards the outlet and penetrate the front spinner face. The penetration may be downwind from a stagnation point. The spiralling of the spiral may be threaded in the opposite direction as the intended rotational direction of the rotor. This should be equivalent to a left hand thread for right hand rotation. Thus, rotating the drain will guide the water towards the outlets of the drain and downstream from the penetration or holes in the cavity.

The aeration or water-air system disclosed to passively convectively drive airflow through said rain separator may auxiliary be further driven by an active fan positioned downstream of the separator. In an example, the location of an active fan may be at the hub-nacelle sliding interface openings, or inside the nacelle provided that the flow is allowed to propagate through the hub into the nacelle.

At suitable locations or connection sections a drop-catcher may be installed along the circumference of the outward channel face at the trailing edge axial-wise position, said drop-catcher being shaped as an L-profile, that will trap surface-rolling drops and prevent said drops from being caught by the channel air jet and propagate into the hub interior.

The outlined water-separation system may also be extended with a funnel or an extension of the cavity.

In an aspect, the aeration or water-air separation system may further comprise a funnel arranged between the cavity and the outlet. Thus, the downstream outlet of the funnel will form the outlet of the system. The funnel has a funnel inlet aperture complementary to the cavity outlet aperture and a funnel face forming the part of the channel face from the cavity face to the outlet.

In an aspect, the funnel face is substantially symmetrical about a symmetry axis. The symmetry axis may be substantially aligned with the rotation axis during intended operation.

In an aspect, the funnel face has at least one major funnel radius about which the funnel face is penetrated at least once to a funnel drain.

An object may be achieved by acts of aerating or separating water and air by using a water-air separation system as disclosed.

Description of the Drawings

Embodiments of the invention will be described in the figures, whereon:

Fig. 1 illustrates a wind turbine generator with a spinner;

Fig. 2 illustrates a water-air separation system with indicative flow lines;

Fig. 3 illustrates a water-air separation system;

Fig. 4 illustrates details of a connection formed as water stop;

Fig. 5 illustrates details a funnel drain;

Fig. 6 illustrates an arrangement of a cavity drain;

Fig. 7 illustrates an arrangement of a spiralling cavity drain; and

Fig. 8 illustrates an embodiment of a capture body with a capture body front face and a capture body rear side separated;

Detailed Description of the Invention

No	Item
1000	Wind turbine
1010	Tower
1020	Nacelle
1030	Rotor
1040	Hub
1050	Blades
1060	Rotation axis
1070	Yaw direction
1100	Exterior
1110	Interior
1200	Symmetry axis
100	Water-air separation system
110	Air
112	Air flow lines
120	Water
122	Water flow lines
200	Spinner
210	Spinner front face
220	Inlet
222	Inlet aperture
230	Outlet
250	Stagnation point
260	Inlet face
300	Channel
310	Channel face
320	Inlet centre flow line
330	Outlet centre flow line
350	Turn angle
400	Cavity
402	Cavity inlet aperture
404	Cavity outlet aperture

410	Cavity face
450	Cavity drain
460	Spiral
500	Capture body
510	Capture body face
512	Capture body front face
514	Capture body rear face
520	Capture suspension means
530	Capture body gap
600	Funnel
610	Funnel face
620	Funnel inlet aperture
625	Funnel outlet aperture
630	Funnel drain
640	Funnel radius
670	Funnel connection

Figure 1 illustrates a wind turbine 1000 having a wind turbine hub 1040 supporting blades 1050 arranged for rotation about a rotation axis 1060 supported by a nacelle 1020, the wind turbine hub 1040 being protected by a spinner 200 separating an exte5 rior 1100 from an interior 1110 and arranged to rotate with the wind turbine hub 1040.

In the following, a water-air separation system will be described with reference to a wind turbine 1000 and the operation of the wind turbine 1000.

Figure 2 illustrates a water-air separation system 100 with reference to a wind turbine generator (WTG) such as illustrated in figure 1. Figure 2 has illustrated flow of air 110 and water 120. Figure 3 details aspects of the water-air separator system 100 from figure 2. In the following details of a water-air separation system 100 refer to figure 2 and 3.

Figure 2 and 3 illustrate a water-air separation system 100 for a wind turbine 1000 having a wind turbine hub 1040 supporting blades 1050 arranged for rotating about a rotation axis 1060 supported by a nacelle 1020. The wind turbine hub 1040 is protected by a spinner 200 separating an exterior 1100 from an interior 1110 and arranged to rotate with the wind turbine hub 1040.

The water-air separation system 100 is configured with the spinner 200 having a spinner front face 210 arranged on the external side 1100 to face in the yaw direction 1070 (compass heading) during intended operation. The spinner front face 210 having an inlet 220 connecting the exterior 1100 with the interior 1110 via a channel 300 with a channel face 310 connecting the inlet 220 with an outlet 230 in the interior 1110. The inlet 220 has an inlet aperture 222.

From the exterior 1100 flow lines of air 110 and water are illustrated as air flow lines 112 and water flow lines 122. The flow lines are illustrated to enter the inlet 220 and can be followed towards the outlet 230. As is apparent, the air flow lines 112 enter the interior 1110 whereas the water flow lines 122 are illustrated to be captured in the water-air separator system 100 and water 120 is directed towards drains as will be described.

The water-air system 100 has a cavity 400 having a cavity face 410. The cavity 400 is penetrated at least once to a cavity drain 450.

The cavity 400 partially surrounds a capture body 500 having a capture body face 510 and is suspended in the cavity 400 by more capture suspension means 520.

The capture suspension means 520 are here rods attached to the cavity face 410 and the capture body 500. The suspension means may be aerodynamically shaped in the flow direction.

In this embodiment, the channel face 310 is substantially symmetrical about a symmetry axis 1200, which symmetry axis 1200 is substantially aligned with the rotation axis 1060 (not shown) during intended operation of the wind turbine generator.

The capture body face 510 is substantially symmetrical about a symmetry axis 1200, which symmetry axis 1200 is substantially aligned with the rotation axis 1060 during intended operation. The cavity body 500 may in itself be symmetrical. The cavity body 500 is shown to be suspended symmetrically, so that it rotates symmetrically about the rotational axis 1060.

The capture body 500 has a capture body front face 512 facing the inlet 220 and arranged to more than cover the projection of the inlet aperture 222. That is that the area of the cross section of the capture body front face 512 is larger than the area of the inlet aperture.

The capture body 500 has a capture body rear face 514 facing the outlet 230. The rear face 514 here is formed with curvature that is more curved than the curvature of the capture body front face 512.

The capture body 500 is seen as an egg-shaped body, here slightly skewed. The capture body 500 has a capture body face 510 that is aerodynamically formed.

The water-air separation system 100 has the capture body 500 arranged in the cavity 400. The cavity face 410 and the capture body face 510 are formed to converge the channel 300 from the inlet 220 towards a minimum channel width and from there to diverge the channel 300 towards the outlet 230.

As shown in figure 3, the water-air separation system 100 has the cavity 400 and the capture body 500 arranged so that the channel 300 has an inlet centre flow line 320 centred between the cavity face 410 and the capture body face 510 and an outlet centre flow line 330 centred between the cavity face 410 and the capture body face 510. The cavity face 410 and the capture body face 510 are formed and arranged so that the inlet centre flow line 320 and the outlet centre flow line 330 break in a turn angle 350. The turn angle 350 is at least 70-degrees.

From figure 3 the spinner front face 210 is substantially symmetrical about a symmetry axis 1200. In a radial cross section there the spinner front face 210 is seen having a stagnation point 250 foremost, i.e. in the yaw-direction. From the stagnation point 250 towards the cavity 400 the inlet 220 has an inlet face 260 that is aerodynamically shaped.

The faces, and including the transitions from one face to another face, are generally smooth and aerodynamically formed. Thus, the channel face 310 is generally smooth and aerodynamically formed.

Also seen from figures 2 and 3 is a water-air separation system 100 including a funnel 600. The water-air separation system 100 may be without the funnel 600.

With the funnel 600 in the water-air separation system 100, the funnel 600 is arranged between the cavity 400 and the outlet 230, which outlet 230 in this case is the outlet of the funnel 600 here shown as a funnel outlet aperture 625. The funnel 600 has a funnel inlet aperture 610 complementary to the cavity outlet aperture 404 and a funnel face 610 forming the part of the channel face 310 from the cavity face 410 to the outlet 230.

In this embodiment, the funnel face 610 is substantially symmetrical about a symmetry axis 1200. The symmetry axis 1200 is substantially aligned with the rotation axis 1060 during intended operation of the wind turbine generator.

The funnel face 610 has at least one major funnel radius 640 about which the funnel face 610 is penetrated at least once to a funnel drain 630. Figure 2 illustrates water flow lines 122 leading the water to the funnel drain 630.

Figure 4 illustrates optional details of the transition from the cavity 400 to the cavity outlet aperture 404 towards the interior 1110. In this embodiment is further shown a drop-catcher 470, which in here has an L-shaped form having one leg attached outside the cavity 400 and the other leg extending into the cavity 400 for catching drops of water.

Figure 5 illustrates details of the connection of a funnel 600 as seen in the transition between the cavity 400 and the funnel 600 in the lower part of figure 3. A structural part of e.g. the spinner forms the cavity face 410 and is bent and extends upstream and forms a part of the funnel face 610A. The funnel 600 is also formed by a structure forming the funnel face 610 that tilts downward towards a funnel connection 670 where there is a funnel drain 630 formed as a gap between the actual spinner 200 and the main structural part of the funnel 600.

Figure 6 illustrates an embodiment of a cavity drain 450 penetrating the cavity face 410. In this embodiment, the penetration is at about the maximum width. In this embodiment, multiple cavity drains 450 are illustrated. The drains are formed so as to guide the separated water away from the cavity 400 (not shown) here is that the cavity drains are formed to lead the water to the exterior of the spinner face. Alternatively, the drains may be connected to a common drain to guide the water away.

Figure 7 illustrates an embodiment of a cavity drain 450 penetrating the cavity face 410. In this embodiment, the penetration is at about the maximum width and is formed as a spiral 460 spiralling towards the inlet 220. The spiralling of the spiral 460 is being threaded as the intended rotational direction of the rotor 1030.

Figure 8 illustrates an alternative embodiment of a capture body 500 having the capture body face 510 with a capture body gap 530 separating a capture body front face 512 and a capture body rear face 514. The capture body gap 530 here shown to be formed by the capture body front face 512 having a smaller extent or radius than the capture rear face 514. Furthermore, the capture body front face 512 extends into the capture rear face 514 thereby being arranged to capture water into the capture body 500. Drain holes in the capture body may be provided as required.

Claims

REQUIREMENTS

A water / air separation system (100) for a wind turbine (1000) having a blade support (1050) wind turbine hub (1040) adapted to rotate about an axis of rotation (1060) supported by a nacelle (1020), the wind turbine hub (1040), which is protected by a spinner (200) which separates an outer (1100) from an inner (1110) and which is arranged to rotate with the wind turbine hub (1040); the water / air separation system (100) is configured with:

the spinner (200) having a spinner surface (210) located on the outer side (1100) against the direction of curvature (1070) away from the nacelle (1020), for intended use, the spinner surface (210) having an inlet (220) connecting the outer (1100) with the inner (1110) via

a channel (300) having a channel surface (310) which connects the inlet (220) to an outlet (230) on the inside (1110) and which has

a cavity (400) with a cavity surface (410) penetrated at least once to a cavity drain (450) and partially encircling

a capture body (500) having a capture body surface (510) having a capture body surface (512) toward the inlet (220) and having a capture body back surface (514) extending away from the front (512) toward the outlet (230), characterized in that the capture body (500) substantially defines a volume suspended in the cavity (400).

Water / air separation system (100) according to claim 1, characterized in that the channel surface (310) is substantially symmetrical about an axis of symmetry (1200), which axis of symmetry (1200) is substantially in line with the axis of rotation (1060), for intended use .

Water / air separation system (100) according to one or more of the preceding claims, characterized in that the capture body surface (510) is substantially symmetrical about an axis of symmetry (1200), which axis of symmetry (1200) is substantially aligned with the axis of rotation (1060). ), for its intended use.

Water / air separation system (100) according to one or more of the preceding claims, characterized in that the capture body (500) has the capture body surface (512) arranged to cover more than the extent of the inlet opening (222).

A water / air separation system (100) according to any one of the preceding claims, wherein the capture body (500) has a capture body back surface (514) formed with a curvature that is more curved than the curvature of the capture body surface (512).

Water / air separation system (100) according to one or more of the preceding claims, characterized in that the capture body (500) is located in the cavity (400), and wherein the cavity surface (410) and the capture body surface (510) are shaped to converge the channel (300) from the inlet (220) towards a minimum channel width and from there diverge the channel (300) towards the outlet (230).

Water / air separation system (100) according to one or more of the preceding claims, characterized in that the duct (300) has a central inlet flow line (320) centered between the cavity surface (410) and the capture body surface (510) and a central outlet flow line ( 330) centered between the cavity surface (410) and the capture body surface (510), wherein the cavity surface (410) and the capture body surface (510) are shaped and arranged so that the central inlet flow line (320) and the central outlet flow line (330) rotate in a pivot angle (330). 350), which angle of rotation (350) is at least 70 degrees.

Water / air separation system (100) according to one or more of the preceding claims, characterized in that the spinner surface (210) is substantially symmetrical about an axis of symmetry (1200), and in the radial cross-section the spinner surface has a stagnation point (250) at the front , and from which stagnation point (250) towards the cavity (400) the spinner surface has an inlet surface (250) which is aerodynamically shaped.

Water / air separation system (100) according to one or more of the preceding claims, characterized in that the cavity drain (450) penetrates the cavity side (410) at the approximately maximum width and is formed as a spiral (460) which winds against the spinner inlet (220) passing through the spinner surface (210), the twist of the coil (460) is threaded as the intended direction of rotation of the rotor (1030).

Water / air separation system (100) according to any one of claims 1 to 8, characterized in that the cavity drain (450) penetrates the cavity surface (410) at the approximately maximum width and is formed as a spiral (460) which winds against the outlet (230) and passes through the spinner surface (210), the twist of the coil (460) is threaded in the opposite direction of the intended direction of rotation of the rotor (1030).

A water / air separation system (100) according to any one of the preceding claims, further comprising a hopper (600) located between the cavity (400) and the outlet (230), said hopper (600) having a hopper inlet opening (610) complementary to the cavity outlet opening (404) and a funnel surface (610) forming the portion of the channel surface (310) from the cavity surface (410) to the outlet (230).

Water / air separation system (100) according to claim 11, characterized in that the funnel surface (610) is substantially symmetrical about an axis of symmetry (1200), which axis of symmetry (1200) is substantially in line with the axis of rotation (1060), for intended use .

Water / air separation system (100) according to claim 11 or 12, characterized in that the funnel surface (610) has at least one main funnel radius (640) about which the funnel surface (610) is penetrated at least once to a funnel drain (630).

A method of venting an interior (1110) of a wind turbine (1000), the method comprising the act of using a water / air separation system (100), according to one or more of claims 1 to 13.