Patent Description:
Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and one or more rotor blades. The rotor blades capture kinetic energy of wind using known foil principles. The rotor blades transmit the kinetic energy in the form of rotational energy so as to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid. <CIT> relates to a wind energy installation having a synchronous generator. <CIT>relates to a method of using additive materials for production of fluid flow channels.

The nacelle typically houses the generator, the gearbox, and various other mechanical and electrical components of the wind turbine. Therefore, such components generate heat that must be cooled off during operation of the wind turbine. Cooling of hot components in wind turbines, particularly cooling of the generator in off-shore wind turbines is currently accomplished using a complex system of ducts, fans, and/or large fabricated heat exchangers. However, such systems are complex, costly, and heavy.

Accordingly, an improved heat transfer assembly configured for cooling off components within the wind turbine nacelle and methods of manufacturing same that addresses the aforementioned issues would be welcomed in the art.

In one aspect, the present disclosure is directed to a nacelle for a wind turbine according to independent claim <NUM>. The nacelle includes a housing defining an outer wall and a heat transfer assembly embedded at least partially within the outer wall of the housing. The heat transfer assembly includes a heat transfer apparatus having a body with a flow path formed in an outer surface thereof and a working fluid configured to flow through the flow path. The heat transfer apparatus also includes a plate member arranged adjacent to the flow path of the body. As such, the plate member and the outer wall of the housing of the nacelle are configured to conduct heat from the working fluid to ambient air.

In one embodiment, the body of the heat transfer apparatus may be formed via at least one of an additive manufacturing process or injection molding. For example, in such embodiments, the additive manufacturing process may include big area additive manufacturing (BAAM), directed energy deposition, or material jetting.

The body is formed of a non-thermally conductive material. In such embodiments, the non-thermally conductive material may include a resin material, a ceramic material, or a low-conductivity material. More specifically, in certain embodiments, the resin material may include a thermoplastic material or a thermoset material.

The plate member is formed of a thermally-conductive material so as to conduct the heat from the working fluid to the ambient air. In such embodiments, the thermally-conductive material may include a metal material. In addition, the working fluid may include a fluid or a gas.

In particular embodiments, the heat transfer apparatus may be sized to fit within a recess of the outer wall of the nacelle of the wind turbine or to fit along a contour of a surface of the nacelle. In another embodiment, an inner surface of the body may face an interior of the nacelle, whereas the outer surface of the body may face the ambient air.

In additional embodiments, the heat transfer apparatus may also include a sealing layer arranged between the body and the plate member so as to minimize leakage of the working fluid. In another embodiment, the plate member may further include one or more protrusions so as to enhance a heat transfer coefficient of the heat transfer apparatus and to minimize an overall size of the heat transfer apparatus.

In several embodiments, the heat transfer apparatus may also include a pump, piping, or a blower for moving the working fluid through the body of the heat transfer apparatus and/or through the wind turbine.

In an embodiment, a heat transfer assembly includes a heat transfer apparatus having a body formed of a non-thermally conductive material via an additive manufacturing process. The body also a flow path formed in an outer surface thereof via the additive manufacturing process. The heat transfer apparatus further includes a working fluid configured to flow through the flow path and a plate member arranged adjacent to the flow path of the body. The plate member is formed of a thermally-conductive material so as to conduct heat from the working fluid to ambient air. It should also be understood that the heat transfer apparatus may further include any of the additional features described herein.

In yet another aspect, the present disclosure is directed to a method for manufacturing a heat transfer apparatus for a wind turbine according to the independent method claim. The method includes forming a base portion of a body of a non-thermally conductive material via an additive manufacturing process. The method also includes forming a flow path on an outer surface of the base portion of the body via the additive manufacturing process. Further, the method includes providing a working fluid within the flow path. Moreover, the method includes arranging a plate member adjacent to the flow path of the body. As such, the plate member is formed of a thermally-conductive material so as to conduct heat from the working fluid to ambient air.

In one embodiment, the method may further include pumping, via one or more pumps and associated piping, the working fluid through or across at least one the body of the heat transfer apparatus, the nacelle, or a tower of the wind turbine. In another embodiment, the method may also include extracting water from the ambient air via a condenser and expelling the water onto the heat transfer apparatus. It should also be understood that the method may further include any of the additional steps and/or features described herein.

Referring now to the drawings, <FIG> illustrates a perspective view of one embodiment of a wind turbine <NUM> according to the present disclosure. As shown, the wind turbine <NUM> generally includes a tower <NUM> extending from a support surface <NUM>, a nacelle <NUM> mounted on the tower <NUM>, and a rotor <NUM> coupled to the nacelle <NUM>. The rotor <NUM> includes a rotatable hub <NUM> and at least one rotor blade <NUM> coupled to and extending outwardly from the hub <NUM>. For example, in the illustrated embodiment, the rotor <NUM> includes three rotor blades <NUM>. However, in an alternative embodiment, the rotor <NUM> may include more or less than three rotor blades <NUM>. Each rotor blade <NUM> may be spaced about the hub <NUM> to facilitate rotation of the rotor <NUM> to enable kinetic energy to be transferred from the wind into usable mechanical energy, and subsequently, electrical energy. For instance, the hub <NUM> may be rotatably coupled to an electric generator <NUM> (<FIG>) positioned within the nacelle <NUM> to permit electrical energy to be produced.

The wind turbine <NUM> may also include a wind turbine controller <NUM> centralized within the nacelle <NUM>. However, in other embodiments, the controller <NUM> may be located within any other component of the wind turbine <NUM> or at a location outside the wind turbine. Further, the controller <NUM> may be communicatively coupled to any number of the components of the wind turbine <NUM> in order to control the components. As such, the controller <NUM> may include a computer or other suitable processing unit. Thus, in several embodiments, the controller <NUM> may include suitable computer-readable instructions that, when implemented, configure the controller <NUM> to perform various different functions, such as receiving, transmitting and/or executing wind turbine control signals.

Referring now to <FIG>, a simplified, internal view of one embodiment of the nacelle <NUM> of the wind turbine <NUM> shown in <FIG> is illustrated. As shown, the wind turbine <NUM> includes the generator <NUM> housed within the nacelle <NUM>, which is coupled to the rotor <NUM> for producing electrical power from the rotational energy generated by the rotor <NUM>. For example, as shown, the rotor <NUM> may include a rotor shaft <NUM> coupled to the hub <NUM> for rotation therewith. The rotor shaft <NUM> may, in turn, be rotatably coupled to a generator shaft <NUM> of the generator <NUM> through a gearbox <NUM> connected to a bedplate support frame <NUM> by a torque support <NUM>. As is generally understood, the rotor shaft <NUM> may provide a low speed, high torque input to the gearbox <NUM> in response to rotation of the rotor blades <NUM> and the hub <NUM>. The gearbox <NUM> may then be configured to convert the low speed, high torque input to a high speed, low torque output to drive the generator shaft <NUM> and, thus, the generator <NUM>.

Each rotor blade <NUM> may also include a pitch adjustment mechanism <NUM> configured to rotate each rotor blade <NUM> about its pitch axis <NUM>. Further, each pitch adjustment mechanism <NUM> may include a pitch drive motor <NUM> (e.g., any suitable electric, hydraulic, or pneumatic motor), a pitch drive gearbox <NUM>, and a pitch drive pinion <NUM>. In such embodiments, the pitch drive motor <NUM> may be coupled to the pitch drive gearbox <NUM> so that the pitch drive motor <NUM> imparts mechanical force to the pitch drive gearbox <NUM>. Similarly, the pitch drive gearbox <NUM> may be coupled to the pitch drive pinion <NUM> for rotation therewith. The pitch drive pinion <NUM> may, in turn, be in rotational engagement with a pitch bearing <NUM> coupled between the hub <NUM> and a corresponding rotor blade <NUM> such that rotation of the pitch drive pinion <NUM> causes rotation of the pitch bearing <NUM>. Thus, in such embodiments, rotation of the pitch drive motor <NUM> drives the pitch drive gearbox <NUM> and the pitch drive pinion <NUM>, thereby rotating the pitch bearing <NUM> and the rotor blade <NUM> about the pitch axis <NUM>. Similarly, the wind turbine <NUM> may include one or more yaw drive mechanisms <NUM> communicatively coupled to the controller <NUM>, with each yaw drive mechanism(s) <NUM> being configured to change the angle of the nacelle <NUM> relative to the wind (e.g., by engaging a yaw bearing <NUM> of the wind turbine <NUM>).

The various components within the nacelle <NUM> may generate excessive heat that needs to be dissipated to ambient air. As such, the present disclosure is directed to a heat transfer assembly <NUM> for cooling off such components within the nacelle <NUM> (or any other location of the wind turbine <NUM>). More specifically, as shown in <FIG>, schematic diagrams of one embodiment of the heat transfer assembly <NUM> according to the present disclosure are illustrated. Further, as shown, the heat transfer assembly <NUM> includes a heat transfer apparatus <NUM>, e.g. embedded within an outer wall <NUM> of the nacelle <NUM>. Thus, as shown in the illustrated embodiment, heat from the generator <NUM> can be removed via a hot fluid path, e.g. via a duct. The heat transfer apparatus <NUM> then receives the hot fluid and cools it down such that the cool or cold fluid can then be sent to a compressor/condenser <NUM>. The compressed cooled fluid can then be recirculated back to the generator <NUM>.

Referring now particularly to <FIG> and <FIG>, the heat transfer apparatus <NUM> also includes a body <NUM> having a base portion <NUM> formed of a non-thermally conductive material <NUM> via an additive manufacturing process. For example, in one embodiment, the non-thermally conductive material <NUM> may be a thermoplastic material or a thermoset material. Further, as shown, the base portion <NUM> of the body <NUM> may define a generally linear cross-sectional shape, i.e. so that the body <NUM> can easily be embedded or recessed with the outer wall <NUM> of the nacelle <NUM>. In addition, as shown, the base portion <NUM> of the body <NUM> includes an inner surface <NUM> and an outer surface <NUM> having a flow path <NUM> extending therefrom. In such embodiments, the flow path <NUM> may also be formed via the additive manufacturing process. Thus, as shown, the flow path <NUM> may be a simple serpentine flow path or a more complex path which is enabled by the additive manufacturing process.

As used herein, additive manufacturing generally refers to processes used to create a three-dimensional object in which layers of material are deposited or formed under computer control to create an object. Thus, in certain embodiments, the additive manufacturing process described herein may include, for example, big area additive manufacturing (BAAM), directed energy deposition, material jetting, or any other suitable additive manufacturing technique.

Still referring to <FIG>, the heat transfer apparatus <NUM> also includes a working fluid <NUM> configured to flow through the flow path <NUM>. In several embodiments, the heat transfer assembly <NUM> may also include a pumping device <NUM>, such as a pump or a blower for moving the working fluid <NUM> through the body <NUM>. In addition, the working fluid <NUM> described herein may be a gas or a liquid. Further, as shown, the heat transfer apparatus <NUM> also includes a plate member <NUM> arranged adjacent to the flow path <NUM> of the body <NUM>. Thus, as shown, the plate member <NUM> may be formed of a thermally-conductive material <NUM> so as to conduct heat from the working fluid <NUM> to ambient air <NUM>. In such embodiments, the thermally-conductive material <NUM> may be a metal material, such as for example, aluminum, steel, or titanium. In certain embodiments, as shown in <FIG> and <FIG>, the plate member <NUM> may have a relatively smooth cross section. Alternatively, as shown in <FIG>, the plate member <NUM> may include one or more protrusions <NUM> or fins to enhance a heat transfer coefficient of the heat transfer apparatus <NUM> and/or to minimize an overall size of the heat transfer apparatus <NUM>.

Referring back to <FIG>, the heat transfer apparatus <NUM> may include a sealing layer <NUM> arranged between the body <NUM> and the plate member <NUM> so as to minimize leakage of the working fluid <NUM>. For example, as shown, the sealing layer <NUM> may include a sealing material <NUM> spaced apart along the flow path <NUM>. In such embodiments, the sealing material <NUM> may be, for example, a polymer, an adhesive, silicone, rubber, or any other suitable sealant.

Referring now to <FIG> and <FIG>, the heat transfer apparatus <NUM> may be sized to fit within a recess <NUM> of the outer wall <NUM> of the nacelle <NUM>. In addition, as shown in <FIG>, the heat transfer apparatus <NUM> may extending along one of the sides of the nacelle <NUM>. Alternatively, as shown in <FIG>, the heat transfer apparatus <NUM> may fit along a contour or edge of the outer wall <NUM> of the nacelle <NUM>. Thus, as shown generally in <FIG>, the inner surface <NUM> of the body <NUM> may face an interior <NUM> of the nacelle <NUM>, whereas the outer surface <NUM> of the body <NUM> may face the ambient air <NUM>.

Referring now to <FIG>, a flow diagram of one embodiment of one embodiment of a method <NUM> for manufacturing a heat transfer apparatus for a wind turbine <NUM> according to the present disclosure is illustrated. In general, the method <NUM> will be described herein with reference to the wind turbine <NUM>, nacelle <NUM>, and heat transfer apparatus <NUM> shown in <FIG>. However, it should be appreciated that the disclosed method <NUM> may be implemented with wind turbines having any other suitable configurations. In addition, although <FIG> depicts steps performed in a particular order for purposes of illustration and discussion, the methods discussed herein are not limited to any particular order or arrangement. One skilled in the art, using the disclosures provided herein, will appreciate that various steps of the methods disclosed herein can be omitted, rearranged, combined, and/or adapted in various ways without deviating from the scope of the present disclosure.

As shown at (<NUM>), the method <NUM> may include forming the base portion <NUM> of the body <NUM> of the non-thermally conductive material <NUM> via an additive manufacturing process. As shown at (<NUM>), the method <NUM> may include forming the flow path <NUM> on or into the outer surface <NUM> of the base portion <NUM> of the body <NUM> via the additive manufacturing process. As shown at (<NUM>), the method <NUM> may include providing the working fluid <NUM> within the flow path <NUM>. As shown at (<NUM>), the method <NUM> may include arranging the plate member adjacent to the flow path <NUM> of the body <NUM>. Further, as mentioned, the plate member <NUM> is formed of the thermally-conductive material <NUM> so as to conduct heat from the working fluid <NUM> to ambient air <NUM>.

In one embodiment, the method <NUM> may further include pumping, via one or more pumps and associated piping, the working fluid <NUM> through or across the body <NUM> of the heat transfer apparatus <NUM>, the nacelle <NUM>, and/or the tower <NUM> of the wind turbine <NUM>. In another embodiment, the method <NUM> may also include extracting water from the ambient air via the condenser <NUM> and expelling the water onto the heat transfer apparatus <NUM>. In other words, the heat transfer apparatus <NUM> provides the ability to pump water up to the nacelle <NUM> via passages or piping in the tower <NUM>. In addition, the condenser can extract water from the air and expel the water onto the surface (plate member/fins) of the heat transfer apparatus <NUM>, i.e. either periodically or constantly via a mist, pore-like orifices in the convection surface, or a steady stream of water running down the convection surface. Such water provides evaporative cooling as needed in order to temporarily enhance the heat transfer coefficient of the heat transfer apparatus <NUM> in times of high thermal loading (e.g. warm or hot days with high power output).

The thermoplastic material as described herein may generally encompass a plastic material or polymer that is reversible in nature. For example, thermoplastic materials typically become pliable or moldable when heated to a certain temperature and returns to a more rigid state upon cooling. Further, thermoplastic materials may include amorphous thermoplastic materials and/or semi-crystalline thermoplastic materials. For example, some amorphous thermoplastic materials may generally include, but are not limited to, styrenes, vinyls, cellulosics, polyesters, acrylics, polysulphones, and/or imides. More specifically, exemplary amorphous thermoplastic materials may include polystyrene, acrylonitrile butadiene styrene (ABS), polymethyl methacrylate (PMMA), glycolised polyethylene terephthalate (PET-G), polycarbonate, polyvinyl acetate, amorphous polyamide, polyvinyl chlorides (PVC), polyvinylidene chloride, polyurethane, or any other suitable amorphous thermoplastic material. In addition, exemplary semi-crystalline thermoplastic materials may generally include, but are not limited to polyolefins, polyamides, fluropolymer, ethyl-methyl acrylate, polyesters, polycarbonates, and/or acetals. More specifically, exemplary semi-crystalline thermoplastic materials may include polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polypropylene, polyphenyl sulfide, polyethylene, polyamide (nylon), polyetherketone, or any other suitable semi-crystalline thermoplastic material.

Further, the thermoset material as described herein may generally encompass a plastic material or polymer that is non-reversible in nature. For example, thermoset materials, once cured, cannot be easily remolded or returned to a liquid state. As such, after initial forming, thermoset materials are generally resistant to heat, corrosion, and/or creep. Example thermoset materials may generally include, but are not limited to, some polyesters, some polyurethanes, esters, epoxies, or any other suitable thermoset material.

Claim 1:
A nacelle (<NUM>) for a wind turbine (<NUM>), the nacelle (<NUM>) comprising:
a housing defining an outer wall (<NUM>); and,
a heat transfer assembly (<NUM>) embedded at least partially within the outer wall (<NUM>) of the housing, the heat transfer assembly (<NUM>) comprising a heat transfer apparatus (<NUM>), the heat transfer apparatus (<NUM>) comprising a body (<NUM>) comprising a flow path (<NUM>) formed in an outer surface (<NUM>) thereof and a working fluid (<NUM>) configured to flow through the flow path (<NUM>), the heat transfer apparatus (<NUM>) further comprising a plate member (<NUM>) arranged adjacent to the flow path (<NUM>) of the body (<NUM>),
wherein the plate member (<NUM>) and the outer wall (<NUM>) of the housing of the nacelle (<NUM>) are configured to conduct heat from the working fluid (<NUM>) to ambient air (<NUM>),
wherein the body (<NUM>) is formed of a non-thermally conductive material (<NUM>), and wherein the plate member (<NUM>) is formed of a thermally-conductive material (<NUM>) so as to conduct the heat from the working fluid (<NUM>) to the ambient air (<NUM>).