Patent Description:
A wind turbine converts wind power into electrical energy by using a generator placed among other equipment in the nacelle of the wind turbine. When the generator converts energy, the air surrounding the equipment is heated, and the equipment itself is thus also heated.

When the equipment is heated, the efficiency with which the conversion occurs is substantially decreased. In order to cool the equipment, the walls and the air surrounding the equipment are cooled down by means of a heat sink positioned on top of the nacelle. Thus, the cool outside air passes through the heat sink and cools a fluid within the heat sink, which is subsequently used to cool the walls, the equipment in the wind turbine or the air surrounding the equipment.

However, such cooling constructions have previously required large and weighty mounting frames for assembly with the wind turbine nacelle, which increases the production costs as well as the costs for assembly and mounting of the wind turbine.

Furthermore, known cooling devices for wind turbine nacelles which are optimised to achieve a large cooling effect have a large amount of relatively thin cooling pipes across the cooling area. This causes an increase in pressure drop due to the pumping of cooling fluid along a lengthy fluid path through the cooling pipes.

To ensure that no negative structural effects on the cooling device and the wind turbine nacelle can occur due to the pressure drop, the cooling device may be dimensioned to be larger, i.e. by having larger cooling pipes and thicker heat exchanger cores, which increases the production costs and requires more costly and complex mounting arrangements. Known heat exchangers are disclosed in <CIT>, <CIT> and <CIT>.

Accordingly, conventional cooling devices have shown not to provide a solution which allows for a less costly mounting arrangement.

It is an object of the present invention to wholly or partly overcome the above disadvantages and drawbacks of the prior art. More specifically, it is an object to provide an improved cooling device which can be mounted to the wind turbine nacelle in a simple and cost-efficient manner and involves lower production costs.

The above objects, together with numerous other objects, advantages, and features, which will become evident from the below description, are accomplished by a solution in accordance with the present invention by an integrally supported cooling device assembly for mounting to a wind turbine nacelle without a mounting frame, the wind turbine nacelle having a first face with a longitudinal extension in a wind direction, and the cooling device assembly comprising:.

Furthermore, the cooling device may be a passive cooling device.

To increase the cooling capacity, the cooling device may comprise a plurality of heat exchanger cores in a row extending along the cooling area.

Moreover, the cooling device may comprise a first fixating beam extending along a first surface of the second manifold, whereby the fixating beam is fixed to the first surface of the second manifold via the suspension means, the fixating beam being adapted to be attached to the first face of the wind turbine nacelle.

Thus, a cooling device which can be mounted to a wind turbine nacelle in a stable and robust manner at a lower cost since less material is required can be achieved.

In one embodiment, the cooling device may further comprise an expansion vessel in fluid connection with one of the manifolds. The expansion vessel further serves to protect the cooling device from excessive cooling fluid pressure. Thereby, the cooling device can be dimensioned according to a lower maximum allowed pressure, which allows for a more cost-efficient and compact cooling device.

In addition, the cooling device may comprise a top fixating beam extending along a top surface of the first manifold, whereby the top fixating beam is fixed to the expansion vessel and the top surface of the first manifold.

The first manifold is adapted to receive a plurality of diagonally extending supporting struts for connecting the cooling device and the first face of the wind turbine nacelle. Thus, further support against the pressure generated by the wind colliding with the cooling area of the cooling device is achieved.

In one embodiment, the first manifold and the second manifold may each have a proximal end and a distal end along a length l of the cooling area, whereby one of the manifolds comprises a coolant inlet arranged in the proximity of the proximal end, and one of the manifolds comprises a coolant outlet arranged in the proximity of the distal end.

The second manifold may comprise the coolant inlet and the coolant outlet. This allows for a more efficient mounting to the wind turbine nacelle since no further interfaces are required in order to connect the inlet and outlet to the cooling system of the wind turbine nacelle.

In one embodiment, the manifolds may be connected by means of a first fluid connection and a second fluid connection, whereby the second manifold comprises a proximal second manifold compartment and a distal second manifold compartment. Said manifold compartments are separate from one another. The first manifold compartment may comprise a proximal first manifold compartment and a distal first manifold compartment, said manifold compartments being separate from one another, whereby the first fluid connection connects the proximal second manifold compartment and the distal first manifold compartment, and the second fluid connection connects the proximal first manifold compartment and the distal second manifold compartment.

Thus, the cooling is effectively divided along the length of the cooling area since a first portion of the cooling fluid is cooled in one section of the cooling device, and a second portion of the cooling fluid is cooled in another. Hence, the sheer volume of cooling fluid meant to pass through each cooling pipe of the heat exchanger core(s) is reduced, whereby a lower pressure drop throughout the cooling area is achieved. A lower pressure drop enables usage of smaller, i.e. thinner, heat exchanger cores, whereby a more cost-efficient as well as lighter cooling device is achieved. Furthermore, it allows for the usage of a less bulky and weighty mounting arrangement for mounting the cooling device on the wind turbine nacelle since the same structural strength is not required.

Furthermore, the heat exchanger core may comprise a plurality of cooling pipes, the cooling pipes having a first flow area, the manifold compartments having a second flow area, and the second flow area being larger than the first flow area. Hereby is obtained that when the cooling fluid is being introduced into the coolant inlet, it will first be distributed in the manifold compartment and led to the second manifold compartment via the connection before entering into the heat exchanger cores.

Additionally, the fluid connections may have a third flow area being equal to or larger than the first flow area.

To further reduce the pressure drop, the first fluid connection may be adapted to distribute approximately <NUM>-<NUM>% of the cooling fluid entering the proximal second manifold compartment directly to the distal first manifold compartment without the cooling fluid entering the heat exchanger cores.

Advantageously, the fluid connections may be disposed at a distance d along the length I from the proximal end, whereby <NUM> < d < <NUM>, and more preferably <NUM> < d <<NUM>. Thus, the structural load generated by the pressure drop becomes more evenly distributed, making the cooling device more robust.

In one embodiment, the cooling device may further comprise a first additional fluid connection connecting the distal second manifold compartment to an additional first manifold compartment and a second additional fluid connection connecting the distal first manifold compartment to an additional second manifold compartment, the additional manifold compartments being disposed along the length l of the cooling area distally to the distal manifold compartments. The additional splitting of the cooling fluid flow allows for an even lower pressure drop.

Preferably, the first and second fluid connections may be disposed at a distance d1 along the length I from the proximal end, and the first and second additional fluid connections are disposed at a distance d2 along the length I from the proximal end, whereby <NUM> < d1 < <NUM> and d2 <NUM> < d2 <<NUM>. Thus, the structural load due to the pressure drop is more evenly distributed along the length of the cooling device.

To further ensure the robustness of the cooling device when mounted to the wind turbine nacelle, the second manifold may be adapted to be further connected to the first face of the wind turbine nacelle via a plurality of supporting legs.

The first fixating beam may, in one embodiment, be fixed to the second manifold by means of a plurality of bolts. Preferably, the plurality of bolts may extend into the second manifold from the first fixating beam in a vertical direction, which allows for a more user-friendly and cost-efficient assembling process.

In one embodiment, the first fixating beam may extend along the first surface of the second manifold over a distance corresponding to <NUM> -<NUM>. Thus, the first fixating beam increases the torsional stiffness of the cooling device in a manner which does not increase the weight of said cooling device drastically.

Preferably, the first fixating beam may a U-profile beam. The U-profile beam allows for the second manifold to be inserted into the profile, which further increases the robustness of the cooling device.

In one embodiment, the top fixating beam may extend along the top surface of the first manifold over a distance corresponding to <NUM> -<NUM>.

The expansion vessel may be fixed to the top fixating beam by means of a plurality of fastening elements. In one embodiment, the fastening elements may be cable ties extending around the expansion vessel.

The length l of the cooling area of the cooling device may be approximately <NUM>-<NUM> metres, and a height h of said cooling area defined by the at least one heat exchanger may be approximately <NUM>-<NUM> metres.

In one embodiment, the coolant inlet and/or the coolant outlet may be connected to fluid lines, each extending through a respective supporting leg.

Finally, the invention also relates to a wind turbine comprising a wind turbine nacelle as described above.

The invention and its many advantages will be described in more detail below with reference to the accompanying schematic drawings, which for the purpose of illustration show some non-limiting embodiments and in which:.

<FIG> shows a perspective view of a wind turbine nacelle <NUM> comprising a cooling device <NUM> for mounting to said wind turbine nacelle <NUM> without a mounting frame, hereinafter referred to as the cooling device <NUM>. The wind turbine nacelle <NUM> is situated on top of a tower and has a front facing a hub <NUM> in which a plurality of rotor blades <NUM>, normally three blades, are fastened. The wind turbine nacelle <NUM> may house a generator and other equipment used for driving the conversion process of wind energy to electricity - also called the drive train. When producing electricity, the drive train produces a lot of heat, resulting in a less effective conversion process.

In other words, the cooling device <NUM> serves to be supported by suspension of its functional components (i.e. the manifolds) without requiring a mounting frame for securing the cooling device to the nacelle <NUM>. Accordingly, the cooling device <NUM> is a self-sustaining cooling device.

In order to cool the equipment and other parts of the nacelle, the cooling device <NUM>, i.e. a self-sustaining cooling device, is arranged outside the nacelle <NUM>. Wind flowing along a longitudinal extension of the nacelle flows in through at least one cooling area of the cooling device <NUM> and cools a fluid within the cooling device. The cooled fluid exchanges heat with the parts of the nacelle <NUM> or equipment to be cooled. The wind turbine nacelle <NUM> has a first face <NUM> with a longitudinal extension in the wind direction.

The present invention will mainly be described in connection with an upwind wind turbine, i.e. a wind turbine where the nacelle is placed downwind from the wind turbine blades. However, the invention may also advantageously be implemented in a downwind wind turbine, i.e. a wind turbine where the nacelle is placed upwind from the wind turbine blades.

<FIG> shows a cooling device <NUM> for the wind turbine nacelle according to the present invention. The wind turbine nacelle <NUM> has the first face <NUM> with a longitudinal extension in a wind direction. The cooling device <NUM> comprises:.

Further referring to <FIG>, the second manifold <NUM> comprises suspension means, and the cooling device <NUM> is adapted to be mounted to the wind turbine nacelle <NUM> by suspension of the second manifold <NUM> to the first face <NUM> of the wind turbine nacelle <NUM> via said suspension means. Thus, the cooling device <NUM> can be mounted to the wind turbine nacelle <NUM> without a heavy mounting frame, which leads to a more expensive mounting process and production process. Advantageously, the cooling device <NUM> may be mounted to the wind turbine nacelle <NUM> solely by suspension of the second manifold <NUM> to the wind turbine nacelle <NUM>. Furthermore, in one embodiment, the self-sustained cooling device <NUM> may be mounted to the wind turbine nacelle <NUM> solely by suspension of any of the manifolds <NUM>, <NUM> or both.

Preferably, the self-sustaining cooling device <NUM> is a passive cooling device.

Said suspension means may include any conventional suspension means, such as a first surface <NUM> of the second manifold <NUM> suitable for welding and a weld (as shown in <FIG>), holes <NUM> for receiving screws or bolts <NUM> (as shown in <FIG>), fixtures or fittings. Notably, the second manifold <NUM> may be suspended to the nacelle both directly by, for example, fittings on the face of the nacelle <NUM> or indirectly by means of, for example, a fixating beam <NUM> (as shown in <FIG>).

A number of suspension means are well-known for the skilled person and suitable for implementing by way of connection to the second manifold <NUM> and will therefore not be described in detail.

To increase the cooling area and/or increase the flexibility of the cooling capacity by adding or subtracting the heat exchanger cores <NUM>, the cooling device <NUM> may, in one embodiment, comprise a plurality of heat exchanger cores <NUM> in a row extending along the cooling area.

By pumping cooling fluid through the cooling pipes extending throughout the heat exchanger core(s), a pressure drop occurs towards the outlet(s) of the heat exchanger due to both the cooling of the cooling fluid in the heat exchanger core(s) and most importantly due to the relatively thin and winding cooling pipes. A solution in order to reduce the pressure drop is described below:
Again referring to <FIG>, the first manifold <NUM> and the second manifold <NUM> each have a proximal end <NUM>, <NUM> and a distal end <NUM>, <NUM> along the length l of the cooling area, i.e. the first manifold <NUM> has the proximal end <NUM> and the distal end <NUM>, and the second manifold <NUM> has the proximal end <NUM> and the distal end <NUM>. In one embodiment, one of the manifolds <NUM>, <NUM> comprises a coolant inlet <NUM> disposed in the proximity of the proximal end <NUM>, <NUM>, and one of the manifolds <NUM>, <NUM> comprises a coolant outlet <NUM> disposed in the proximity of the distal end <NUM>, <NUM>.

Preferably, the second manifold <NUM> comprises the coolant inlet <NUM> and the coolant outlet <NUM>. This allows for simpler fitting of the cooling device <NUM> to the cooling system interface situated inside the wind turbine nacelle <NUM> since the cooling fluid does not have to be rerouted by means of connecting hoses to the first manifold from the wind turbine nacelle or by having additional structures with passages for leading the cooling fluid upwards towards the first manifold of the cooling device.

With further reference to <FIG>, the manifolds <NUM>, <NUM> are connected by means of a first fluid connection <NUM> and a second fluid connection <NUM>. The fluid connections <NUM> and <NUM> extend outside the heat exchanger cores <NUM>. The second manifold <NUM> comprises a proximal second manifold compartment <NUM> and a distal second manifold compartment <NUM>, said manifold compartments being separate from one another, i.e. said compartments are not in direct fluid communication. The first manifold compartment <NUM> comprises a proximal first manifold compartment <NUM> and a distal first manifold compartment <NUM>, said manifold compartments being separate from one another, i.e. said compartments are not in direct fluid communication. The first fluid connection <NUM> connects the proximal second manifold compartment <NUM>, and the distal first manifold compartment <NUM> and the second fluid connection <NUM> connect the proximal first manifold compartment <NUM> and the distal second manifold compartment <NUM>.

Hence, fluid communication is provided between the first and second manifolds without the cooling fluid entering the cooling pipes of the heat exchanger cores <NUM>. The flow of cooling fluid running through the cooling pipes of the one or more heat exchanger cores <NUM> is thus split, effectively reducing the pressure drop through the cooling device <NUM>.

The compartments of the second manifold <NUM> and the first manifold <NUM> may be separate manifold units extending along the length of the cooling area connected by means of the fluid connections <NUM>, <NUM>. Said compartments may also be achieved by providing the second manifold <NUM> and the first manifold <NUM> with fluid-tight separating walls.

The fluid connections <NUM> and <NUM> may be, for example, hoses or pipes which extend in a vertical direction parallel to cooling pipes of the heat exchanger cores <NUM>. Advantageously, the ends of each fluid connection are bent so as to connect to the compartments of the first manifold <NUM> and second manifold <NUM>.

Referring to <FIG>, the cooling fluid flow through the cooling device <NUM> is depicted. The cooling fluid flow is referenced with the arrows extending through the cooling device <NUM>. As seen in said figure, the cooling fluid flows through the cooling device <NUM> in a figure-<NUM>-type manner, wherein the cooling fluid enters the cooling device via the inlet <NUM> and exits via the outlet <NUM>.

The warm cooling fluid entering through the inlet <NUM> is led into the proximal second manifold compartment <NUM> of the second manifold <NUM>, wherein it is distributed through the heat exchanger cores <NUM> connected to said compartment. However, a portion of the cooling fluid will be led through the fluid connection <NUM> and thereby enter the distal first manifold compartment <NUM> of the first manifold <NUM>. In the distal first manifold compartment <NUM>, the warm cooling fluid is led downwards through the cooling pipes of the heat exchanger cores <NUM> connected with said compartment, thus entering the distal second manifold compartment <NUM>. Said distal second manifold compartment is connected with the outlet <NUM>, whereby the cooling fluid is led back into the wind turbine nacelle.

The portion of the cooling fluid which is led upwards through the heat exchanger cores connected to the proximal second manifold compartment <NUM> is led into the proximal first manifold compartment <NUM> and is consequently cooled along the way. The now cooled cooling fluid inside said proximal first manifold compartment <NUM> is led to the distal second manifold compartment <NUM> by means of the second fluid connection <NUM>. Said distal second manifold compartment is connected with the outlet <NUM>, whereby the cooling fluid is led back into the wind turbine nacelle.

Thus, all of the cooling fluid entering the cooling device is cooled while the cooling flow is effectively split between different portions of the cooling area, i.e. different heat exchanger cores <NUM>. Due to the cooling fluid's tendency to choose the path of the least resistance and the length of the fluid connections being similar to the length of the cooling pipes of the heat exchanger cores, a portion of the cooling fluid will pass through the first fluid connection <NUM> without entering the heat exchanger cores <NUM> in fluid communication with the manifold compartments <NUM> and <NUM>. Hence, not all of the cooling fluid will be forced to enter through the thin cooling pipes at the same position along the cooling area, whereby the pressure drop is severely reduced. This allows for usage of lighter and less bulky radiators which can be supported solely by suspension of the second manifold <NUM>, i.e. not requiring a mounting frame.

To minimise the pressure drop, the first fluid connection <NUM> is adapted to distribute approximately <NUM>-<NUM>% of the cooling fluid entering the proximal second manifold compartment <NUM> directly to the distal first manifold compartment <NUM> without the cooling fluid entering the heat exchanger cores <NUM>.

Accordingly, approximately <NUM>-<NUM>% of the cooling fluid will be cooled directly through the aforementioned heat exchanger cores <NUM> and then pass to the outlet <NUM> via the second fluid connection <NUM> and the distal second manifold compartment <NUM>. This may be achieved by dimensioning the length and/or flow diameter of the first fluid connection <NUM> so as to alter the pressure distribution in relation to the cooling pipes of the heat exchanger cores <NUM>.

A lowering of the pressure drop may, for example, enable the use of a cooling device which is cheaper to manufacture and mount to a wind turbine nacelle. This may be achieved via a less bulky and weighty mounting arrangement and/or thinner heat exchanger cores since said heat exchanger cores do not have to be dimensioned to withstand a high pressure drop.

As is known to the skilled person, the most optimal flow pattern through a cooling device is for the cooling fluid to flow diagonally from top to bottom. Hence, it is particularly advantageous to utilise the split-flow features described above in a cooling device with the inlet <NUM> and <NUM> in connection to the second manifold <NUM>. This allows for a cooling device which is easier and more cost-efficient to mount to an existing wind turbine nacelle by allowing for mounting in a single plane, i.e. the face <NUM> of the nacelle. Furthermore, the split-flow features allow for a diagonal flow between the first and second manifolds through the cooling device, which leads to a more efficient cooling in comparison to a non-split cooling device with the inlet and the outlet being connected to the second manifold since the cooling device <NUM> at least partly achieves the desired diagonal flow pattern (between the distal manifold compartments). Accordingly, a cooling device which is both more efficient in terms of cooling and easier to mount to a wind turbine nacelle is achieved.

Referring again to <FIG>, the fluid connections <NUM>, <NUM> may be disposed at the distance d along the length I from the proximal end <NUM>, <NUM>, whereby <NUM> < d < <NUM>, and more preferably <NUM> < d <<NUM>. Thus, the structural load generated by the pressure drop is distributed more evenly along the length of the cooling device, making the cooling device more robust and sturdier.

To further decrease the pressure drop, further fluid connections and separate compartments of the first and second manifolds may be provided. Accordingly, the cooling device <NUM> may further comprise a first additional fluid connection connecting the distal second manifold compartment <NUM> to an additional first manifold compartment and a second additional fluid connection connecting the distal first manifold compartment <NUM> to an additional second manifold compartment, the additional manifold compartments being disposed along the length l of the cooling area distally to the distal manifold compartments <NUM>, <NUM>.

To optimise the distribution of the load generated by the pressure drop, the first and second fluid connections <NUM>, <NUM> may be disposed at a distance d1 along the length I from the proximal end <NUM>, <NUM>, and the first and second additional fluid connections may be disposed at a distance d2 along the length I from the proximal end <NUM>, <NUM>, whereby <NUM> < d1 < <NUM> and <NUM> < d2 <<NUM>.

As is recognised by the skilled person, any number of evenly distributed additional fluid connections and manifold compartments along the length of the cooling area may be applicable.

A split-flow solution according to any of the aforementioned examples is especially beneficial in conjunction with a cooling device according to the invention since a lowering of the pressure drop enables the usage of heat exchanger(s) with smaller dimensions. Thereby, a lighter self-sustaining mounting arrangement can be achieved without risking structural damage due to the frictional shear forces associated with the pressure drop as well as the load exerted on the cooling device due to the difference in pressure along the cooling area. The mounting of a cooling device to a wind turbine nacelle is a complicated as well as resource and time-consuming process due to the large dimensions and high weight of the cooling device as well as the altitude of the wind turbine nacelle. Accordingly, it is essential to achieve a lighter, more efficient cooling device which can be mounted without adding further complex structural components, as is enabled with the aforementioned embodiments of the cooling device <NUM>.

Again referring to <FIG>, to achieve a cooling device which can be mounted in a safer and more robust manner to the wind turbine nacelle without requiring a weighty mounting frame, the cooling device may further comprise a first fixating beam <NUM> extending along a first surface <NUM> of the second manifold <NUM>, the fixating beam <NUM> being fixed to the first surface <NUM> of the second manifold <NUM> via the suspension means, and the fixating beam being adapted to be attached to the first face <NUM> of the wind turbine nacelle <NUM>. The fixating beam <NUM> may be attached to the first face <NUM> via a support structure <NUM> of the wind turbine nacelle. The first fixating beam <NUM> serves to increase the stability and torsional rigidity of the cooling device <NUM> during transport. Furthermore, it is particularly advantageous with a plurality of heat exchanger cores <NUM> since this allows for a more robust cooling device which keeps the heat exchanger cores <NUM> aligned and secured in a robust manner.

The suspension means may, for example, be a weld extending along the first surface <NUM> connecting to the fixating beam or threaded holes <NUM> for receiving bolts <NUM> connecting the fixating beam and the second manifold, as depicted in <FIG>.

As seen in <FIG>, the first fixating beam <NUM> may extend along the first surface <NUM> of the second manifold <NUM> along a distance corresponding to between <NUM> and <NUM>. Thereby, an increased torsional rigidity is achieved.

The cooling device <NUM> may further comprise an expansion vessel <NUM> in fluid connection with one of the manifolds <NUM>, <NUM>. Thus, the cooling device becomes more robust and sustainable for rapid changes in pressure due to the expansion vessel being partially filled with air which can absorb excess pressure as well as cushion shocks due to water hammer. The expansion vessel <NUM> may have a volume of between <NUM> and <NUM> litres.

Advantageously, the cooling device <NUM> may further comprise a top fixating beam <NUM> extending along a top surface <NUM> of the first manifold <NUM>, whereby the top fixating beam <NUM> is fixed to the expansion vessel <NUM> and the top surface <NUM> of the first manifold <NUM>. The positioning of the expansion vessel on top of the first manifold allows for a more compact cooling device. Furthermore, positioning the expansion vessel above the heat exchanger cores facilitates possible generated steam as well as reduces the pressure in the cooling pipes of the heat exchanger cores.

Preferably, the top fixating beam is fixed to the first manifold <NUM> by means of bolts extending into the first manifold <NUM>.

With reference to <FIG>, the expansion vessel <NUM> may be fixed to the second fixating beam <NUM> by means of a plurality of fastening elements <NUM>. Preferably, the fastening elements may be cable ties connected to the second fixating beam <NUM> and extending around the expansion vessel <NUM>.

The cooling device <NUM> may be further adapted to be connected to the first face <NUM> of the wind turbine nacelle <NUM> via a plurality of supporting legs <NUM>. Accordingly, the coolant inlet <NUM> and/or the coolant outlet <NUM> may be connected to fluid lines, each extending through a respective supporting leg <NUM>, whereby said fluid lines are adapted to lead the cooling fluid to and from the wind turbine nacelle.

Referring again to <FIG> and <FIG>, the first manifold <NUM> is configured to receive a plurality of diagonally extending supporting struts <NUM> (shown in <FIG>) for connecting the cooling device <NUM> and the first face <NUM> of the wind turbine nacelle <NUM>. Said struts extend diagonally downwards towards the first face <NUM> of the wind turbine nacelle <NUM>. The struts provide additional support for the cooling device when it is mounted to the wind turbine nacelle. The struts may advantageously be in the form of metal wires connected to the wind turbine nacelle <NUM> and the first manifold <NUM>. According to some embodiments, the second fixating beam <NUM> may be adapted to receive a plurality of diagonally extending support struts <NUM> for connecting the cooling device <NUM> and the first face <NUM> of the wind turbine nacelle <NUM>. The second fixating beam or first manifold may be adapted to receive the struts by any conventional means, such as, for example, by comprising a plurality of eye bolts or loops, each adapted to receive one of the diagonal struts.

The provision of the struts <NUM> allows for compensation for the pressure exercised on the cooling area by the wind. Accordingly, the struts <NUM> may extend from a backside in relation to the wind direction of the first manifold <NUM> or the second fixating beam <NUM>.

Preferably, again referring to <FIG>, the length l of the cooling area defined by the at least one heat exchanger core <NUM> is approximately <NUM>-<NUM> metres. A height h of said cooling area defined by the at least one heat exchanger core <NUM> may be approximately <NUM>-<NUM> metres.

Turning to <FIG>, a cross-section view of a part of the second manifold <NUM> is depicted. The first fixating beam <NUM> is fixed to the second manifold <NUM> by means of a plurality of bolts <NUM>. The bolts <NUM> extend through said first fixating beam <NUM> (not shown in <FIG>). Preferably, the plurality of bolts <NUM> extend into the second manifold <NUM> from the first fixating beam <NUM> in a vertical direction. Thus, the risk of material damage is reduced compared to having the bolts extend through a side surface of the manifold. This is due to the thickness of the material along the bottom of the second manifold usually being thicker than the side surfaces of said second manifold. A more robust and reliable assembly process is therefore achieved.

In one embodiment, the bolts <NUM> may be adapted to be received by threaded holes <NUM> extending vertically into the second manifold <NUM>. Hence, the suspension means may be comprised of the threaded holes <NUM> disposed on the first surface <NUM>.

Referring to <FIG>, the first fixating beam <NUM> may be a U-profile beam which allows for the second manifold <NUM> to be inserted into the profile. This increases the stability and robustness of the cooling device <NUM>, especially if it comprises a plurality of heat exchanger cores <NUM>. As seen in said <FIG>, the U-profile beam <NUM> is adapted to receive the second manifold <NUM>, preferably in a close fit. Hence, load can be transferred from the heat exchanger cores <NUM> in an efficient manner.

With further reference to <FIG>, the U-profile beam <NUM> may comprise holes for receiving the fluid connections <NUM>, <NUM>. Furthermore, the cooling device may comprise an additional protective plate protecting said fluid connections <NUM>, <NUM>.

Claim 1:
An integrally supported cooling device assembly (<NUM>) for mounting to a wind turbine nacelle (<NUM>) without a mounting frame, the wind turbine nacelle (<NUM>) having a first face (<NUM>) with a longitudinal extension in a wind direction, and the cooling device assembly (<NUM>) comprising:
- at least one heat exchanger core (<NUM>) configured to extend across the wind direction and to define a cooling area of the integrally supported cooling device assembly (<NUM>), the heat exchanger core (<NUM>) having a first side (<NUM>) and a second side (<NUM>) arranged opposite the first side in relation to the heat exchanger core,
- a first manifold (<NUM>) being arranged along the first side and a second manifold (<NUM>) being arranged along the second side, each in fluid communication with the at least one heat exchanger core (<NUM>), the first manifold (<NUM>) and the second manifold (<NUM>) extending parallelly along the cooling area,
- the second manifold (<NUM>) comprises suspension means (<NUM>), and the cooling device assembly (<NUM>) is adapted to be mounted to the wind turbine nacelle (<NUM>) by suspension of the second manifold (<NUM>) to the first face (<NUM>) of the wind turbine nacelle (<NUM>) via said suspension means (<NUM>), characterised in that the cooling device assembly further comprises:
- a plurality of diagonally extending supporting struts (<NUM>) for connecting the cooling device assembly (<NUM>) and the first face (<NUM>) of the wind turbine nacelle (<NUM>),
wherein the plurality of diagonally extending supporting struts are connected to the first manifold (<NUM>), and
wherein the supporting struts are positioned on a side of the cooling device assembly facing the wind direction.