Patent Description:
Wind turbines are used to produce electrical energy using a renewable resource and without combusting a fossil fuel. Generally, a wind turbine converts kinetic energy from the wind into electrical power. A horizontal-axis wind turbine includes a tower, a nacelle located at the apex of the tower, and a rotor having a plurality of blades and supported in the nacelle by means of a shaft. The shaft couples the rotor either directly or indirectly with a generator, which is housed inside the nacelle. Consequently, as wind forces the blades to rotate, electrical energy is produced by the generator.

Components of the generator located within the nacelle generate significant heat during operation, which in turn, causes the temperature of the nacelle walls and the generator components to increase. When the generator components are heated, the overall efficiency of power generation may be decreased. Therefore, the generator components and the nacelle may be cooled to ensure that the heat does not adversely affect power generation and/or damage the components.

Conventional wind turbines may include one or more cooling devices configured to remove the heat generated during operation of the wind turbine. The cooling devices may include standard heat sinks. Another exemplary cooling device is a cooler top positioned along one side (e.g., the top surface or roof) of the nacelle and including one or more panels partially enclosed by a cover or spoiler to encourage air flow over the panels. The air flowing past the wind turbine cools a second fluid free flowing through the panels, the second fluid being directed to other heat exchangers within the nacelle to remove heat from generator components and the nacelle. To this end, the cooling devices operate without being separately powered to thereby reduce the temperature of the nacelle and the generator components.

Conventional wind turbines may include a heliplatform or helihoist platform (hereinafter collectively referred to generally as a "heliplatform") adjacent to the nacelle for receiving a helicopter or supplies/personnel hoisted from a hovering helicopter to the heliplatform. The heliplatform includes a platform, a railing surrounding the platform, and a support structure for the platform. As the heliplatform is configured to support workers and/or a helicopter carrying workers, the placement of the heliplatform in relation to the nacelle is typically subject to numerous safety regulations in certain countries. For example, the railing of the heliplatform must conform to a minimum height safety standard. Additionally, the heliplatform (e.g., including the railing) may be required to be the highest point of the wind turbine, excluding the blades. Consequently, the support structure for the heliplatform must position the heliplatform at least coplanar with the highest point of the nacelle or above the nacelle to fully comply with such safety regulations. In conventional wind turbines, the heliplatform is generally positioned at a rear end of the nacelle roof (e.g., opposite to the rotor) to comply with these regulations. However, when a cooling device such as the cooler top is added to a wind turbine, the conventional placement of a heliplatform may no longer comply with safety regulations because the platform and/or railing thereof may be located below the level of the cover or spoiler.

Furthermore, conventional wind turbines may include a crane or winch for moving replacement or new components delivered to the nacelle. For example, the crane or winch may include a service crane operable within the nacelle. A wind turbine equipped with an internal nacelle crane and a helihoist platform is disclosed in <CIT>. However, conventional cranes or winches are typically not operable to move components to or from the heliplatform when the heliplatform is positioned mostly behind the nacelle. In this regard, conventional cranes and winches cannot extend over the heliplatform to move items onto and off of the heliplatform. Accordingly, during significant repair or restoration of the wind turbine, a larger secondary crane may need to be mounted on rails on the nacelle to provide crane operational coverage at the heliplatform as well as the nacelle roof. Mounting and removing this secondary crane is expensive and inefficient because this process adds significant downtime to the repair or restoration of a wind turbine.

Thus, there remains a need for an improved cooler and heliplatform arrangement that addresses these and other shortcomings in conventional wind turbines. Furthermore, there is also a need for an improved crane that addresses these and other shortcomings in conventional wind turbines.

Accordingly, there is proposed a wind turbine as defined in appended claim <NUM>. Further optional features thereof are defined in subclaims <NUM>-<NUM>. There is also proposed a method of using a wind turbine as defined in appended claim <NUM>. Further optional features thereof are defined in appended subclaims <NUM>-<NUM>.

Accordingly, a wind turbine includes a tower and a nacelle located adjacent the top of the tower and having a nacelle roof. The wind turbine also includes a rotor with a hub and at least one wind turbine blade operatively coupled to a generator housed within the nacelle. The wind turbine further includes a heliplatform having a support structure extending from the nacelle. A crane is coupled to the nacelle and is configured to move between a stowed position underneath the nacelle roof and an operational position. In the operational position, the crane is selectively positionable over the heliplatform.

A method of using a wind turbine is also provided. The wind turbine includes a nacelle having a nacelle roof with a plurality of openable panels, a crane supported by the nacelle, and a heliplatform. The method includes opening at least one of the panels in the nacelle roof to uncover the crane. The crane may be moved from a stowed position underneath the nacelle roof to an operational position. In the operational position, the crane is selectively positionable above the heliplatform. The method also includes hoisting items on the heliplatform into the nacelle through at least one of the panels with the crane. The method may also include moving the crane from the operational position back to the stowed position underneath the nacelle roof, and closing the plurality of panels to cover the crane. In embodiments, a wind turbine includes a tower and a nacelle located adjacent the top of the tower and having a nacelle roof. The wind turbine also includes a rotor with a hub and at least one wind turbine blade operatively coupled to a generator housed within the nacelle. The generator is configured to produce electrical power from the rotation of the wind turbine blade. According to the invention the wind turbine includes a cooler having a spoiler and at least one cooler panel projecting above the nacelle roof. Such a cooler removes heat from the interior of the nacelle. A heliplatform includes a support structure extending from the nacelle and may be at least partially integrated with the cooler.

The heliplatform may further include a platform and a railing surrounding the platform, each of which may be substantially coplanar with the spoiler in alternative embodiments. A front portion of the platform may project forward of the cooler panels while a rear portion of the platform may be disposed rearward of the cooler panels. To accommodate the platform, the cooler panels may define a gap for the platform, or one of the cooler panels may be pivotally mounted so that the cooler panel can open to provide access between the front and rear portions of the platform. The support structure may further include at least one triangular frame at least partially integrated with the cooler.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the invention.

With reference to <FIG>, a wind turbine <NUM> includes a tower <NUM>, a nacelle <NUM> disposed at the apex of the tower <NUM>, and a rotor <NUM> operatively coupled to a generator <NUM> housed inside the nacelle <NUM>. In addition to the generator <NUM>, the nacelle <NUM> houses miscellaneous components required for converting wind energy into electrical energy and various components needed to operate, control, and optimize the performance of the wind turbine <NUM>. The tower <NUM> supports the load presented by the nacelle <NUM>, the rotor <NUM>, and other components of the wind turbine <NUM> that are housed inside the nacelle <NUM>, and also operates to elevate the nacelle <NUM> and rotor <NUM> to a height above ground level or sea level, as may be the case, at which faster moving air currents of lower turbulence are typically found.

The rotor <NUM> of the wind turbine <NUM>, which is represented as a horizontal-axis wind turbine, serves as the prime mover for the electromechanical system. Wind exceeding a minimum level will activate the rotor <NUM> and cause rotation in a substantially perpendicular direction to the wind direction. The rotor <NUM> of wind turbine <NUM> includes a central hub <NUM> and at least one blade <NUM> that projects outwardly from the central hub <NUM>. In the representative embodiment, the rotor <NUM> includes three blades <NUM> circumferentially distributed about the central hub <NUM>, but the number may vary. The wind turbine blades <NUM> are configured to interact with the passing air flow to produce lift that causes the rotor <NUM> to spin generally within a plane defined by the blades <NUM>.

The wind turbine <NUM> may be included among a collection of similar wind turbines belonging to a wind farm or wind park that serves as a power generating plant connected by transmission lines with a power grid, such as a three-phase alternating current (AC) power grid. The power grid generally consists of a network of power stations, transmission circuits, and substations coupled by a network of transmission lines that transmit the power to loads in the form of end users and other customers of electrical utilities. Under normal circumstances, the electrical power is supplied from the generator <NUM> to the power grid as known to a person having ordinary skill in the art.

In order to provide cooling for the generator <NUM> and the nacelle <NUM>, the wind turbine <NUM> according to a first embodiment includes a cooler <NUM> as shown in <FIG>. The wind turbine <NUM> also includes a heliplatform <NUM> for receiving a helicopter or turbine components and/or working personnel hoisted from a hovering helicopter (i.e. , the heliplatform <NUM> also functions as a helihoist platform). To this end, the wind turbine <NUM> of the embodiment shown in <FIG> includes a cooler and heliplatform arrangement described in further detail below. The wind turbine <NUM> of this embodiment may also include a crane <NUM> for moving items to and from the nacelle <NUM> and the heliplatform <NUM>, the crane <NUM> being shown in phantom in <FIG>.

As shown in <FIG>, the nacelle <NUM> includes an outer housing <NUM> defined, at least in part, by a nacelle roof <NUM>, a rear wall <NUM>, and a pair of sidewalls 36a, 36b. The rear wall <NUM> of the nacelle <NUM> generally faces a direction opposite from the hub <NUM> and wind turbine blades <NUM>. The rear wall <NUM> may be oriented to be upwind or downwind from the wind turbine blades <NUM> in various embodiments. The nacelle roof <NUM> may have a paneled configuration and include a plurality of panels <NUM> configured to be opened as shown in <FIG> to provide access between the interior of the wind turbine <NUM> and the exterior surroundings of the nacelle <NUM>. The panels <NUM> may cover a substantial portion of the surface area of the nacelle roof <NUM> so that replacement parts and components may be hoisted into the nacelle <NUM> close to the point of installation or removal. The panels <NUM> are illustrated as hinged panels in the current embodiment, but it will be appreciated that the panels <NUM> may be slidable or otherwise moveable between opened and closed positions in other embodiments. The panels <NUM> are generally configured to be opened individually by separate mechanical actuators (not shown), as is well understood in the field of wind turbines.

To ensure efficient and safe operation of the wind turbine <NUM>, the cooler <NUM> is provided to remove heat generated within the nacelle <NUM> by the generator <NUM> and other interior components. The cooler <NUM> includes many of the same elements as the cooling device disclosed in International Patent Publication No. <CIT>, which is owned by the assignee of the present application. As shown in <FIG>, the cooler <NUM> includes a spoiler <NUM> (also referred to as a "cover" in the cooler art) and a plurality of cooler panels <NUM> projecting upwardly from the nacelle roof <NUM> so as to generally extend between the nacelle roof <NUM> and the spoiler <NUM>. The cooler panels <NUM> operate as heat exchangers that transfer heat in a first fluid (e.g. , coolant, refrigerant, etc.) flowing through the cooler panels <NUM> to a second fluid (e.g. , wind) flowing around the cooler panels <NUM>. Preferably, the cooler <NUM> operates as a free-flow cooling device wherein wind is encouraged to pass over the cooler panels <NUM> to cool the first fluid flowing in the cooler panels <NUM> without the assistance of fans or other actuators requiring power from the generator <NUM>.

The cooler panels <NUM> shown in <FIG> may be rigidly coupled to the nacelle roof <NUM> and the spoiler <NUM>. Alternatively, the cooler panels <NUM> may be flexibly coupled to one of the nacelle roof <NUM> and the spoiler <NUM> to ensure that position fluctuations of the spoiler <NUM> or expansion/contraction of the cooler panels <NUM> does not damage the cooler <NUM>. The cooler panels <NUM> may be disposed generally perpendicular to the nacelle roof <NUM> to maximize a flow area in the path of wind flowing past the nacelle <NUM>. However, it will be understood that the cooler panels <NUM> may be disposed at a non-perpendicular angle to the nacelle roof <NUM> and be within the scope of this invention. The cooler panels <NUM> are arranged in a row or series with small spacing between adjacent cooler panels <NUM> to permit wind to pass through the cooler <NUM>. For example, adjacent cooler panels <NUM> may be separated by a distance of between about <NUM> millimeters and about <NUM> millimeters. Each of the cooler panels <NUM> may be connected to shared supply and return lines (not shown) configured to deliver coolant or refrigerant to and from the cooler panels <NUM> and the interior components of the nacelle <NUM> that require cooling. Multiple supply and return lines may be provided in alternative embodiments.

The spoiler <NUM> includes a top wall <NUM> and a pair of arms <NUM> extending downwardly from the top wall <NUM> to form a generally inverted U-shaped member. Each of the arms <NUM> may be coupled to the corresponding sidewalls 36a, 36b of the nacelle <NUM> as shown most clearly in <FIG>, for example. The top wall <NUM> and arms <NUM> are elongate in a direction parallel to the nacelle roof <NUM> to thereby form a flow channel at least partially surrounding the cooler panels <NUM>. The flow channel between the nacelle roof <NUM> and the spoiler <NUM> encourages air flowing past the nacelle <NUM> to flow over and through the plurality of cooler panels <NUM>, thereby increasing the cooling effect of the cooler <NUM>. It will be appreciated that the top wall <NUM> and the arms <NUM> may be angled with respect to the direction of air flow to promote optimal cooling in other embodiments. The top wall <NUM> of the spoiler <NUM> is positioned above the nacelle roof <NUM> and is therefore the top structure of the wind turbine <NUM> (excluding the blades <NUM>).

To comply with many local and/or national regulations, the heliplatform <NUM> must be positioned at least as high as the top wall <NUM> of the spoiler <NUM>. To this end, the heliplatform <NUM> includes a support structure <NUM> composed of two generally triangular frame members <NUM>. Each of the frame members <NUM> includes a top leg 50a extending generally horizontally and configured to underlie (e.g. , directly engage) a platform <NUM> of the heliplatform <NUM>. Each of the frame members <NUM> also includes a front leg 50b extending forwardly and downwardly from one end of the top leg 50a through the cooler panels <NUM> and the nacelle roof <NUM> to an interior frame structure <NUM> (see <FIG>) of the nacelle <NUM>. The frame members <NUM> further include a rear leg 50c extending forwardly and downwardly from the other end of the top leg 50a through the outer housing <NUM> and the interior frame structure <NUM> of the nacelle <NUM>. It will be understood that the front leg 50b and rear leg 50c of each frame member <NUM> may be joined at the same location at the interior frame structure <NUM> of the nacelle <NUM>, or may alternatively be spaced from one another at the interior frame structure <NUM> of the nacelle <NUM> in various embodiments. In this regard, the frame members <NUM> provide structural support for the heliplatform <NUM> to position at least a portion of the heliplatform <NUM> as the highest structure of the wind turbine <NUM> other than the wind turbine blades <NUM>.

As shown in <FIG>, the platform <NUM> includes an upper surface 52a configured to receive replacement components, workers, or a helicopter, a lower surface 52b disposed on or adjacent the frame members <NUM>, and an outer periphery 52c defining the shape of the platform <NUM>. The heliplatform <NUM> may further include a railing <NUM> or fence that generally surrounds the upper surface 52a at the outer periphery 52c. The railing <NUM> is configured to prevent items or workers (one worker shown for illustrative purposes in <FIG>) from sliding or blowing off the heliplatform <NUM>. According to the safety regulations discussed above, the top 56a of the railing <NUM> must be the highest structure (or at least coplanar with the highest structure) on the wind turbine <NUM> (excluding the blades <NUM>). In this regard, the support structure <NUM> may support the top 56a of the railing <NUM> above the nacelle roof <NUM> and the top wall <NUM> of the spoiler <NUM>. In the embodiment shown in <FIG>, the platform <NUM> is supported so as to be substantially coplanar or adjacent to the top wall <NUM> of the spoiler <NUM>. As clearly shown in <FIG>, this positioning of the heliplatform <NUM> does place the top 56a of the railing <NUM> as the highest structure on the wind turbine <NUM>, notwithstanding the blades <NUM>. It will be understood that the support structure <NUM> may support the heliplatform <NUM> in difference positions than those shown in the figures in other embodiments, as long as the top 56a of the railing <NUM> is at least as high in elevation as the spoiler <NUM>.

The platform <NUM> includes a front portion <NUM> (i.e. , where the worker is standing in <FIG>) extending forwardly from the cooler panels <NUM> and the spoiler <NUM>, and a rear portion <NUM> extending rearward of the cooler panels <NUM> and the spoiler <NUM>. The plurality of cooler panels <NUM> may include a gap <NUM> configured to receive the platform <NUM> between the front portion <NUM> and the rear portion <NUM> as shown in <FIG>. However, when the platform <NUM> is positioned so as to be substantially coplanar with the spoiler <NUM>, as shown in <FIG>, the gap <NUM> may be omitted in some embodiments. The front portion <NUM> may be used by a worker as shown in <FIG> to inspect the nacelle roof <NUM> or to observe operation of the crane <NUM> described in further detail below. The rear portion <NUM> may be larger than the front portion <NUM> so as to accommodate large replacement components or a helicopter, as understood in the wind turbine art. The rear portion <NUM> may also include an elevator or ladder (not shown) for transporting a worker from the heliplatform <NUM> to an access door or skylight (not shown) of the nacelle <NUM>. Such a system would allow a worker to gain access to the interior of the nacelle <NUM>.

As shown most clearly in <FIG> and <FIG>, the heliplatform <NUM> may be at least partially integrated structurally with the spoiler <NUM>. More particularly, the support structure <NUM> and/or the platform <NUM> may be at least partially integrated with the top wall <NUM> of the spoiler <NUM>. In one exemplary embodiment, the support structure <NUM> may be integral with the spoiler <NUM> such that the supporting elements for the cooler <NUM> and the heliplatform <NUM> are substantially integrated with each other. The heliplatform <NUM> may be composed of a mixture of protruded fiberglass material and steel. For example, the platform <NUM> may be composed of a higher percentage of fiberglass material than steel such that the platform <NUM> is structurally sound yet lightweight. Limiting the weight of the heliplatform <NUM> is important because the heliplatform <NUM> is generally located off the center of gravity of the nacelle <NUM>. Consequently, the fiberglass and steel mixture provides a desirable balance between structural strength and weight forces applied by the heliplatform <NUM> to the nacelle <NUM> and the tower <NUM>. It will be appreciated, however, that the heliplatform <NUM> may be composed of other materials in alternative embodiments without departing from the scope of this invention.

<FIG> illustrate the operation of the crane <NUM> incorporated with the nacelle <NUM> for use with the heliplatform <NUM> according to the first embodiment. In one example, the crane <NUM> may be a hydraulic knuckle-boom crane commercially available from Palfinger AG of Bergheim, Salzburg Austria. However, other commercially-available crane designs may be used within the scope of this invention. The crane <NUM> is configured to be stowed completely within the nacelle <NUM> as shown in <FIG> in a first stowed position. The crane <NUM> is also configured to move to a second operational position. In the operational position, the crane <NUM> may be moved above the various panels <NUM> on the nacelle roof <NUM>, or may be moved to the location shown in <FIG> wherein the free end <NUM> of the telescoping boom <NUM> of the crane <NUM> is disposed over the heliplatform <NUM> so as to hoist items to and from the heliplatform <NUM>. Consequently, when the crane <NUM> is in the operational position as shown in <FIG>, the crane <NUM> is operable to move components from the heliplatform <NUM> to the correct location within the nacelle <NUM> through the corresponding panel <NUM> on the nacelle roof <NUM>. Although the free end <NUM> of the boom <NUM> is illustrated over the front portion <NUM> of the platform <NUM> in <FIG>, it will be understood that the crane <NUM> may be configured to extend to the rear portion <NUM> of the platform <NUM> in some embodiments.

As shown most clearly in <FIG>, the nacelle roof <NUM> has a generally planar profile in the first embodiment of the wind turbine <NUM>. To this end, the nacelle roof <NUM> may be raised uniformly in all areas from the interior frame structure <NUM> and components of the nacelle <NUM>. A plurality of roof support members <NUM> may be disposed between the nacelle roof <NUM> and the interior frame structure <NUM>, as shown in <FIG>. These roof support members <NUM> provide adequate space for the crane <NUM> to be completely stowed within the nacelle <NUM> and underneath the nacelle roof <NUM> when the panels <NUM> are closed as shown, for example, in phantom in <FIG>. Furthermore, the roof support members <NUM> also provide adequate clearance between the interior frame structure <NUM> and the nacelle roof <NUM> to enable the crane <NUM> to move and operate completely within the nacelle <NUM> with the panels <NUM> closed. In this regard, the crane <NUM> is configured to be operable to move components around the interior of the nacelle <NUM> without subjecting the interior components of the nacelle <NUM> to the outside environment (e.g. , the panels <NUM> may be closed).

In this embodiment, a portion of the panels <NUM> on the nacelle roof <NUM> define a cover <NUM> for the crane <NUM>. The cover <NUM> is opened by rotating or otherwise moving the panels <NUM> above the boom <NUM> of the crane <NUM> from the closed position in <FIG> to the opened position in <FIG>. As discussed above, the movement of the panels <NUM> between the open and closed positions may be enabled by known mechanical or electrical actuators. After the boom <NUM> of the crane <NUM> is lifted above the plane of the nacelle roof <NUM>, a portion of the panels <NUM> forming the cover <NUM> may be closed, as shown in <FIG>, to limit unnecessary exposure of the interior components of the nacelle <NUM> to the external environment. However, the panels <NUM> forming the cover <NUM> may also be left open during operation of the crane <NUM> outside the nacelle <NUM>. The crane <NUM> may then be moved between the nacelle roof <NUM> and the heliplatform <NUM>, as previously described and shown in <FIG>.

A second embodiment of the wind turbine <NUM> according to the invention is illustrated in <FIG> and <FIG>. This embodiment of the wind turbine <NUM> includes many of the same elements previously described with reference to <FIG>, and these elements have been provided with the same reference numbers. In this embodiment, the support structure <NUM> has been lowered such that the front portion <NUM> of the platform <NUM> extends through the gap <NUM> in the cooler panels <NUM>. The top 56a of the railing <NUM> of the heliplatform <NUM> is positioned substantially coplanar with the top wall <NUM> of the spoiler <NUM> as shown in <FIG>. Consequently, the top 56a of the railing <NUM> remains the highest structure on the wind turbine <NUM> (excluding the blades <NUM>) so as to comply with safety regulations. A worker or a replacement component may be moved between the rear portion <NUM> of the platform <NUM> and the front portion <NUM> by moving through the gap <NUM> in the cooler panels <NUM> underneath the spoiler <NUM>. It will be understood that the support structure <NUM> may be modified in other embodiments to position the heliplatform <NUM> at any height above the position shown in <FIG> and <FIG> within the scope of this invention.

In the second embodiment of the wind turbine <NUM>, the nacelle roof <NUM> includes a bifurcated sliding cover <NUM> configured to cover the crane <NUM> in the stowed position instead of the cover <NUM> formed by the panels <NUM> of the previously-described embodiment. The sliding cover <NUM> includes a forward portion <NUM> and a rear portion <NUM>. The forward portion <NUM> and the rear portion <NUM> each include a raised portion <NUM> projecting above the nacelle roof <NUM> and a second portion <NUM> configured to be substantially coplanar with the remainder of the nacelle roof <NUM>. The boom <NUM> of the crane <NUM> is configured to snugly fit within the raised portion <NUM> when the cover <NUM> is closed, as shown in <FIG>. In this regard, the crane <NUM> is generally not operable within a closed nacelle <NUM>, in contrast to that described with reference to the first embodiment.

To deploy the crane <NUM>, the forward portion <NUM> of the cover <NUM> may be configured to slide forwardly, and the rear portion <NUM> of the cover <NUM> may be configured to slide rearward along the nacelle roof <NUM>. The sliding movement of the forward portion <NUM> and rear portion <NUM> may be enabled by known mechanical or electrical actuators. When the forward portion <NUM> and rear portion <NUM> are opened, as shown in <FIG>, the crane <NUM> may be moved to the operational position above the nacelle roof <NUM>. As with the previous embodiment, and as shown in <FIG>, the telescoping boom <NUM> of the crane <NUM> may be extended so that items may be moved from the heliplatform <NUM> to the interior of the nacelle <NUM> through one or more of the selected panels <NUM>. When movement of items is complete, the crane <NUM> may be moved back to the stowed position shown in <FIG> such that the bifurcated cover <NUM> may be moved back to the closed position.

A third embodiment of the wind turbine <NUM> according to the invention is illustrated in <FIG> and <FIG>. This embodiment of the wind turbine <NUM> includes many of the same elements previously described with reference to <FIG>, and these elements have been provided with the same reference numbers. In this embodiment, the support structure <NUM> is located in the same position as the previous embodiment of <FIG> and <FIG> such that the front portion <NUM> of the platform <NUM> extends through the gap <NUM> in the cooler panels <NUM>. The top 56a of the railing <NUM> of the heliplatform <NUM> is again positioned substantially coplanar with the top wall <NUM> of the spoiler <NUM>, as shown in <FIG>. Consequently, the top 56a of the railing <NUM> remains the highest structure on the nacelle <NUM> so as to comply with safety regulations. A worker or a replacement component may be moved between the rear portion <NUM> of the platform <NUM> and the front portion <NUM> by moving through the gap <NUM> in the cooler panels <NUM> underneath the spoiler <NUM>.

In the third embodiment of the wind turbine <NUM>, the nacelle roof <NUM> includes a unitary sliding cover <NUM> configured to cover the crane <NUM> in a stowed position instead of the cover <NUM> formed by the panels <NUM> of the first-described embodiment. The unitary cover <NUM> includes a raised portion <NUM> projecting above the nacelle roof <NUM> and a second portion <NUM> configured to be substantially coplanar with the remainder of the nacelle roof <NUM>. The boom <NUM> of the crane <NUM> is configured to snugly fit within the raised portion <NUM> when the cover <NUM> is closed, as shown in <FIG>. In this regard, the crane <NUM> is generally not operable within a closed nacelle <NUM>, in contrast to that described with reference to the first embodiment.

To deploy the crane <NUM>, the cover <NUM> may be configured to slide rearward along the nacelle roof <NUM>. The sliding movement of the cover <NUM> may be enabled by known mechanical or electrical actuators. When the cover <NUM> is opened, as shown in <FIG>, the crane <NUM> may be moved to the operational position above the nacelle roof <NUM>. As with the previous embodiment, and as shown in <FIG>, the telescoping boom <NUM> of the crane <NUM> may be extended so that items may be moved from the heliplatform <NUM> to the interior of the nacelle <NUM> through one or more of the selected panels <NUM>. When movement of items is complete, the crane <NUM> may be moved back to the stowed position shown in <FIG> such that the unitary cover <NUM> may be moved back to the closed position. It will be understood that the bifurcated cover <NUM> and the unitary cover <NUM> may be modified to pivotally open or slide open in a different direction in other embodiments within the scope of this invention.

Another embodiment of the wind turbine <NUM> according to the invention is illustrated in <FIG>. This embodiment of the wind turbine <NUM> includes many of the same elements previously described with reference to <FIG>, and these elements have been provided with the same reference numbers. In this embodiment, the gap <NUM> in the cooler panels <NUM> has been partially filled with a central cooler panel <NUM> having an upper panel portion <NUM> and a lower panel portion <NUM>. The upper panel portion <NUM> may be pivotally coupled to the spoiler <NUM> by a hinge (not shown) or similar connector such that the upper panel portion <NUM> is rotatable between a closed position shown in <FIG> and an open position shown in <FIG>. In the closed position, the upper panel portion <NUM> is generally coplanar or aligned with the remaining cooler panels <NUM>. In the open position, the upper panel portion <NUM> is rotated out of alignment with the remaining cooler panels <NUM> such that passage of items or workers between the front portion <NUM> and the rear portion <NUM> of the platform <NUM> is enabled. Alternatively, the upper panel portion <NUM> may be pivotally coupled to the heliplatform <NUM> and/or an adjacent cooler panel <NUM> in other embodiments.

It will be understood that the upper panel portion <NUM> may be operatively coupled with the lower panel portion <NUM> such that the second fluid flowing through the upper panel portion <NUM> may be routed into the nacelle <NUM> for cooling interior components of the nacelle, as previously described with reference to the cooler panels <NUM>. Moreover, the lower panel portion <NUM> is illustrated as spaced from the nacelle roof <NUM> in the illustrated embodiment, but the lower panel portion <NUM> may alternatively be pivotally coupled to the nacelle roof <NUM> by a hinge (not shown) or similar connector such that the lower panel portion <NUM> may also be rotated between a closed position and an open position. For example, this moveable lower panel portion <NUM> may be provided in embodiments with sliding covers <NUM>, <NUM> having raised portions <NUM>, <NUM> that must pass through the cooler panels <NUM> underneath the heliplatform <NUM>. It will also be understood that the upper panel portion <NUM> and the lower panel portion <NUM> may be coupled together for unitary rotational movement about one or more hinge-like connections with the spoiler <NUM> and/or the nacelle roof <NUM>.

<FIG> also illustrate that the plurality of cooler panels <NUM> may include corresponding openings <NUM> configured to receive the front legs 50b of the triangular frame members <NUM> making up the support structure <NUM> for the heliplatform <NUM>. In this regard, the plurality of cooler panels <NUM> may be modified as necessary to receive the various members of the support structure <NUM> at least partially integrated with the spoiler <NUM> and the cooler <NUM>.

In summary, the wind turbines <NUM>, <NUM>, <NUM>, <NUM> of the present invention incorporate the support structure <NUM> for a heliplatform <NUM> with a cooler <NUM> such that the railing <NUM> of the heliplatform <NUM> is disposed at the highest point on the wind turbine <NUM> (excluding the blades <NUM>). The wind turbine <NUM> therefore advantageously provides both a cooler <NUM> and a heliplatform <NUM> while complying with various safety regulations for wind turbines. Furthermore, the wind turbine <NUM> of the present invention includes a crane <NUM> that is operable to move items to and from the heliplatform <NUM> and the interior of the nacelle <NUM>. The crane <NUM> is stowed within the nacelle <NUM> when not in use by providing a cover <NUM>, <NUM>, <NUM> on the nacelle roof <NUM> as described in further detail above.

Claim 1:
A wind turbine, comprising:
a tower (<NUM>);
a nacelle (<NUM>) disposed adjacent a top of the tower and including a nacelle roof (<NUM>); a rotor (<NUM>) including a hub (<NUM>) and at least one wind turbine blade (<NUM>) operatively coupled to a generator (<NUM>) housed within the nacelle (<NUM>);
a heliplatform (<NUM>) including a support structure (<NUM>) extending from the nacelle (<NUM>); and a crane (<NUM>) coupled to the nacelle (<NUM>) and configured to move between a first stowed position underneath the nacelle roof (<NUM>) and a second operational position, the crane (<NUM>) being selectively positionable in the second operational position over the heliplatform (<NUM>) characterised by comprising:
a cooler (<NUM>) including a spoiler (<NUM>) and at least one cooler panel (<NUM>) projecting above the nacelle roof (<NUM>), the cooler (<NUM>) operable to remove heat from an interior of the nacelle (<NUM>), wherein the crane (<NUM>) is operable in the operational position to hoist items from the heliplatform (<NUM>) over the cooler (<NUM>) and into the nacelle (<NUM>) through the nacelle roof (<NUM>).