Cooling device for components of wind turbines

Abstract

A cooling device for components of wind turbines, comprising at least one conduit (3) containing therein a working fluid (5) selected to change from a liquid to gas phase, and vice versa, during operation; wherein a first lower portion of each conduit (3) is inserted into a receptacle (2) through which a primary coolant fluid (10) transporting heat from a component of a wind turbine to be cooled (7) circulates, said lower portion acting as an evaporator of the working fluid (5); and wherein a second upper portion of each conduit (3) remains outside the receptacle (2), acting as a condenser of the working fluid (5).

Claims

1. A cooling device for components of wind turbines, comprising a plurality of conduits, each conduit containing therein a working fluid selected to change from a liquid to gas phase, and vice versa, during operation; wherein a first lower portion of each conduit is inserted into a receptacle through which a primary coolant fluid transporting heat from a component of a wind turbine to be cooled circulates, said lower portion acting as an evaporator of the working fluid; and wherein a second upper portion of each conduit remains outside the receptacle, acting as a condenser of the working fluid; wherein: each conduit is sealed at both ends; and the plurality of conduits includes a first conduit holding a first working fluid and a second conduit holding a second working fluid, wherein the first and second working fluids have different boiling points.

2. The cooling device according to claim 1, wherein the second upper portion of each conduit projects from the roof of a nacelle of the wind turbine.

3. The cooling device according to claim 2, further comprising a nozzle responsible for housing the upper portion of each conduit and increasing the speed of the outer fluid.

4. A cooling device for components of wind turbines, comprising a plurality of conduits, each conduit containing therein a working fluid selected to change from a liquid to gas phase, and vice versa, during operation; wherein a first lower portion of each conduit is inserted into a component of a wind turbine through which a primary coolant fluid transporting heat circulates, said lower portion acting as an evaporator of the working fluid; and wherein a second upper portion of each conduit remains outside the component of the wind turbine, acting as a condenser of the working fluid; wherein: each conduit is sealed at both ends; and the plurality of conduits includes a first conduit holding a first working fluid and a second conduit holding a second working fluid, wherein the first and second working fluids have different boiling points.

5. The cooling device according to claim 1, wherein the receptacle connected to the component of the wind turbine to be cooled comprises a recirculation pump for recirculating the primary coolant fluid.

6. The cooling device according to claim 5, wherein the component of the wind turbine to be cooled is any one of the following: a generator of the wind turbine; a multiplier of the wind turbine; a transformer of the wind turbine; control electronics of a power converter of the wind turbine.

7. The cooling device according to claim 5, further comprising ducts through which the primary coolant fluid circulates from and to the receptacle and the component of the wind turbine to be cooled.

8. The cooling device according to claim 1, further comprising at least one hermetic seal to assure leak-tightness between the receptacle and each conduit.

9. The cooling device according to claim 8, wherein the hermetic seal is flexible.

10. The cooling device according to claim 1, wherein the first lower portion of each conduit extends, forming a chamber common to the plurality of conduits.

11. The cooling device according to claim 1, wherein the second upper portion of each conduit extends, forming a chamber common to the plurality of conduits.

12. The cooling device according to claim 1, wherein each conduit is sealed at one end.

13. The cooling device according to claim 1, wherein the working fluid inside each conduit is subjected to a pressure greater than an atmospheric pressure.

14. The cooling device according to claim 1, wherein a plurality of fins is coupled to the second portion of each conduit.

15. The cooling device according to claim 14, wherein the plurality of fins include an upper seal of each conduit.

16. The cooling device according to claim 14, wherein the plurality of fins includes metal fins.

17. The cooling device according to claim 1, wherein each conduit is tubular.

18. The cooling device according to claim 1, wherein the component to be cooled is a component of an onshore, offshore, or underwater wind turbine.

19. The cooling device according to claim 1, wherein the each conduit comprises end segments made of a metal material and an intermediate segment made of a flexible and electrically insulating material.

20. The cooling device according to claim 1, wherein a plurality of fins is coupled to the first lower portion of each conduit.

21. The cooling device according to claim 4, wherein the component of the wind turbine is any one of the following: a nacelle of the wind turbine; a compartment of a transformer of the wind turbine; a receptacle of a hydraulic unit of the wind turbine; ducts through which the primary coolant fluid circulates.

Description

DESCRIPTION OF THE DRAWINGS

(1) The invention will be described below in more detail in reference to the attached drawings in which:

(2) FIGS. 1A and 1B show a diagram depicting the cooling device in which the receptacle through which the primary fluid circulates and the conduit extending to the heat discharge point are seen.

(3) FIGS. 2A and 2B show an alternative embodiment of the cooling device in which the receptacle is the component to be cooled itself.

(4) FIG. 3 depicts a detail of the end of a conduit with fins.

(5) FIGS. 4A and 4B depict the cooling device applied for cooling different components of a wind turbine.

(6) FIG. 5 depicts the possible embodiment in which a nozzle, arranged on the outside of the nacelle of the wind turbine, houses the upper portion of each conduit.

DETAILED DESCRIPTION OF THE INVENTION

(7) The object of the invention is a device for discharging heat generated by various components of a wind turbine. The device comprises one or more conduits extending from a receptacle through which the primary fluid transporting heat from the component to be cooled to the discharge point in contact with the outside air circulates. Said conduits contain therein a working fluid which undergoes a phase change, transporting heat from one point to another.

(8) The component to be cooled (7) has no heat spot concentrated in a single element, and it is therefore advisable to concentrate it so as to be discharged by means of a primary coolant fluid (10). This fluid can be, for example: air, water, a mixture of water and glycol, oil, etc. Ducts (9) through which the primary fluid (10) circulates driven by means of a recirculation pump for recirculating the fluid are arranged between the component to be cooled (7) and the receptacle (2). These ducts can be, for example, tubings, pipes, hydraulic connections, air ducts, openings for communication between the component and the receptacle, etc.

(9) In the embodiment of the invention shown in FIGS. 1A (schematic side view) and 1B (schematic perspective view), the component to be cooled (7) is connected to a receptacle (2) into which at least one preferably tubular-shaped conduit (3) is inserted.

(10) A working fluid (5) performs a phase change-based thermodynamic cycle inside the conduit. The lower part of the conduit (3) (referred to as evaporator) receives the heat to be dissipated and the fluid in liquid phase evaporates and transforms into vapor. Due to the difference in densities existing between the liquid and vapor state of all fluid, said vapor moves upward to the higher and colder part of the conduit (3) (referred to as condenser) where it condenses, giving off latent heat, and again moving downward by gravity to the lower part. The working fluid (5) repeats this cycle over and over again, a quick heat transfer in one direction from top to bottom thus being obtained.

(11) The dimensions of the receptacle (2) as well as the dimensions of the conduit (3) will be adapted according to the power to be dissipated and the environmental conditions of the surroundings.

(12) Optionally, as shown in FIGS. 2A (schematic side view) and 2B (schematic perspective view), the receptacle (2) can be the component to be cooled (7) itself: the nacelle itself, the compartment of the transformer, the receptacle of the hydraulic unit, the ducts through which the primary fluid circulates, etc.

(13) The conduit (3) is selected for each application based on its fundamental parameters: material, thickness, length, etc. The material can be copper, for example.

(14) The working pressure of the conduit (3) must also be considered when determining the material and the thickness so that there will be no deformations which may reduce heat transfer.

(15) The first hermetic seal (4) at the end of the conduit (3) assures leak-tightness of the conduit to the selected design conditions. Seals made by compression, hydraulic seals, seals with epoxy resins, etc. can be used, for example.

(16) A second hermetic seal (8) allows assuring leak-tightness between the receptacle (2) and the conduit (3) to prevent the leakage of the primary fluid (10). A sealing gasket, hydraulic seal, weld, etc. can be used, for example. The second hermetic seal (8) can be a flexible seal such that it allows immediately adjusting the height or axial displacement of the conduits (3), in addition to a very quick assembly.

(17) The working fluid (5) can be a coolant fluid, for example, R-134-a or the like.

(18) FIG. 3 shows a possible embodiment of the part of the condenser of the conduit (3) where metal fins (6) are installed for the purpose of making more surface available for heat exchange between the conduit itself and the outside air. Said fins (6) can be, for example, corrugated metal plates or flat discs inserted, welded, or embedded in the conduit itself, arranged horizontally, vertically, in a spiral, etc. The main function of these fins (6) is to increase the surface for passive heat transfer with respect to the air.

(19) Alternatively, the fins can be built as a single assembly and with different shapes. In this case, the conduit (3) can be sealed against this assembly which would perform the function of a condenser.

(20) The cooling device may comprise the fins (6) coupled to the first portion of the conduits (3) additionally and alternatively to the coupling of the fins (6) to the second portion of the conduit. With the coupling of the fins (6) to the first portion of the conduits (3), the contact surface and thereby heat transfer are increased.

(21) FIGS. 4A and 4B depict the cooling device applied to different components of the wind turbine.

(22) The application of the cooling device in FIG. 4A corresponds with the diagram of FIG. 1A, where the device comprises a receptacle (2) which is connected with the component to be cooled (7), in this case, the multiplier (11) of a wind turbine. FIG. 4A shows the cooling of the multiplier (11) of a wind turbine using an intermediate receptacle (2) into which the conduits (3) are inserted, the receptacle being connected by means of ducts (9) to the mechanical pump (12) and to the return inlet of the multiplier (11) itself. The pump (12) is responsible for recirculating the primary coolant fluid (oil).

(23) However, the application shown in FIG. 4B corresponds to the diagram of FIG. 2A since, in this case, the receptacle is the component to be cooled (7) itself, in this case, the receptacle (15) of a hydraulic unit of the wind turbine. FIG. 4B shows the cooling of the hydraulic unit of a wind turbine using the actual receptacle (15) of the hydraulic pump assembly for inserting the conduits (3) therein, and thereby discharging heat from the oil to the outside air.

(24) FIG. 5 shows the possible embodiment in which a nozzle (19) arranged on the outside of the nacelle (18) of the wind turbine houses the upper portion of each conduit (3). In the embodiment schematically shown in FIG. 5, the upper portion of each conduit (3) (i.e., the condensers of the conduits) projects from the roof of the nacelle (18) of the wind turbine. The condensers of the conduits are housed in a nozzle (19) generating a tunnel effect, increasing the speed of the outside air and thereby increasing system capacity. The nozzle (19) is a good complement for cooling the nacelle (18) and the compartment of the transformer, and is also useful for cooling the rest of the components of the wind turbine if the conduits (3) extend above the roof of the nacelle. This nozzle (19) takes advantage of the fact that the nacelle (18) is always oriented towards the wind when the wind turbine is working, and that when more cooling is required (i.e., when more power is generated) it is due to there being higher wind speed.