CA2916779A1 - Method for de-icing a rotor blade of a wind turbine - Google Patents
Method for de-icing a rotor blade of a wind turbine Download PDFInfo
- Publication number
- CA2916779A1 CA2916779A1 CA2916779A CA2916779A CA2916779A1 CA 2916779 A1 CA2916779 A1 CA 2916779A1 CA 2916779 A CA2916779 A CA 2916779A CA 2916779 A CA2916779 A CA 2916779A CA 2916779 A1 CA2916779 A1 CA 2916779A1
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- Canada
- Prior art keywords
- rotor blade
- air stream
- air
- circuit
- icing
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- 238000000034 method Methods 0.000 title claims abstract description 51
- 238000010438 heat treatment Methods 0.000 claims abstract description 77
- 230000008569 process Effects 0.000 claims description 16
- 230000001419 dependent effect Effects 0.000 claims description 6
- 238000007791 dehumidification Methods 0.000 claims description 5
- 239000003570 air Substances 0.000 description 154
- 230000009849 deactivation Effects 0.000 description 9
- 238000010926 purge Methods 0.000 description 9
- 238000009529 body temperature measurement Methods 0.000 description 6
- 238000005192 partition Methods 0.000 description 6
- 239000012080 ambient air Substances 0.000 description 5
- 239000000428 dust Substances 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 238000009413 insulation Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 238000012544 monitoring process Methods 0.000 description 4
- 238000009434 installation Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 230000035508 accumulation Effects 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 2
- 238000009530 blood pressure measurement Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000007710 freezing Methods 0.000 description 2
- 230000008014 freezing Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000004913 activation Effects 0.000 description 1
- 238000005273 aeration Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 238000000265 homogenisation Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
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- 230000009467 reduction Effects 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03D—WIND MOTORS
- F03D1/00—Wind motors with rotation axis substantially parallel to the air flow entering the rotor
- F03D1/06—Rotors
- F03D1/065—Rotors characterised by their construction elements
- F03D1/0658—Arrangements for fixing wind-engaging parts to a hub
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03D—WIND MOTORS
- F03D1/00—Wind motors with rotation axis substantially parallel to the air flow entering the rotor
- F03D1/06—Rotors
- F03D1/065—Rotors characterised by their construction elements
- F03D1/0675—Rotors characterised by their construction elements of the blades
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03D—WIND MOTORS
- F03D80/00—Details, components or accessories not provided for in groups F03D1/00 - F03D17/00
- F03D80/40—Ice detection; De-icing means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- F05B2240/00—Components
- F05B2240/20—Rotors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- F05B2240/00—Components
- F05B2240/20—Rotors
- F05B2240/30—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- F05B2260/00—Function
- F05B2260/20—Heat transfer, e.g. cooling
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- F05B2260/00—Function
- F05B2260/20—Heat transfer, e.g. cooling
- F05B2260/205—Cooling fluid recirculation, i.e. after having cooled one or more components the cooling fluid is recovered and used elsewhere for other purposes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/70—Wind energy
- Y02E10/72—Wind turbines with rotation axis in wind direction
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T50/00—Aeronautics or air transport
- Y02T50/60—Efficient propulsion technologies, e.g. for aircraft
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- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Wind Motors (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
The invention relates to a method for de-icing a rotor blade (5) of a wind turbine (1), wherein an air stream (13, 14) is conducted through the rotor blade (5) by way of a fan (22), wherein the air stream (13, 14) is conducted in a circuit by way of an air-guiding system (9) and, furthermore, the air stream (13, 14) is heated by way of a heating device (21). The method according to the invention is characterized in that a fraction of the air stream (13, 14) that is conducted in the circuit is removed from the circuit.
Description
Method for de-icing a rotor blade of a wind turbine Description The invention relates to a method for de-icing a rotor blade of a wind turbine, wherein an air stream is conducted through the rotor blade by way of a fan, wherein the air stream is conducted in a circuit by way of an air-guiding system and, furthermore, the air stream is heated by way of a heating device.
Rotor blade de-icing devices of wind turbines, and methods for de-icing a rotor blade of a wind turbine, are basically known. In this regard, reference is made to the applicant's EP 2 585 713 Bl.
In the case of the known method for de-icing a rotor blade of a wind turbine, the rotor blade has a first and a second duct within the rotor blade for conducting an air stream, wherein the air stream comprises a heated air stream which is introduced into the first duct and which flows at least in sections in a direction from the rotor blade root to the rotor blade tip in a predefinable flow guide and which, for the purposes of de-icing at least a section of the rotor blade, flows along at least a part of an outer wall of the rotor blade.
It is an object of the present invention to provide an improved and efficient method for de-icing a rotor blade of a wind turbine, or for de-icing the rotor blades of a wind turbine.
Rotor blade de-icing devices of wind turbines, and methods for de-icing a rotor blade of a wind turbine, are basically known. In this regard, reference is made to the applicant's EP 2 585 713 Bl.
In the case of the known method for de-icing a rotor blade of a wind turbine, the rotor blade has a first and a second duct within the rotor blade for conducting an air stream, wherein the air stream comprises a heated air stream which is introduced into the first duct and which flows at least in sections in a direction from the rotor blade root to the rotor blade tip in a predefinable flow guide and which, for the purposes of de-icing at least a section of the rotor blade, flows along at least a part of an outer wall of the rotor blade.
It is an object of the present invention to provide an improved and efficient method for de-icing a rotor blade of a wind turbine, or for de-icing the rotor blades of a wind turbine.
- 2 -Said object is achieved by means of a method for de-icing a rotor blade of a wind turbine, wherein an air stream is conducted through the rotor blade by way of a fan, wherein the air stream is conducted in a circuit by way of an air-guiding system and, furthermore, the air stream is heated by way of a heating device, which method is refined in that a fraction of the air stream that is conducted in the circuit is removed from the circuit.
By means of the method according to the invention, it is ensured, in an efficient manner, that the corresponding rotor blade is de-iced, wherein preferably, the air stream is conducted by way of an air-guiding system in the rotor blade to the locations which are to be preferentially de-iced. For this purpose, a rotor blade de-icing device of a wind turbine is preferably provided, wherein the wind turbine has a rotor with at least one rotor blade attached to a hub, wherein the rotor blade de-icing device has a heating device, a fan and an air-guiding system.
The air-guiding system preferably has a first duct, which conducts an air stream in the direction of a rotor blade tip, and a second duct, which conducts the air stream in the direction of the hub. The air stream that is conducted in the direction of the rotor blade tip is preferably an air stream that has been heated by the heating device. The air stream that is then conducted back is preferably a cooled air stream. The cooling arises in particular as a result of a release of heat to the rotor blade external material, in order to melt ice adhering thereto. Here, the ducts may preferably be of insulated form in sections in order that the least possible heat losses arise at locations at which the rotor blade does not necessarily have to be de-iced. It is preferable for the in particular
By means of the method according to the invention, it is ensured, in an efficient manner, that the corresponding rotor blade is de-iced, wherein preferably, the air stream is conducted by way of an air-guiding system in the rotor blade to the locations which are to be preferentially de-iced. For this purpose, a rotor blade de-icing device of a wind turbine is preferably provided, wherein the wind turbine has a rotor with at least one rotor blade attached to a hub, wherein the rotor blade de-icing device has a heating device, a fan and an air-guiding system.
The air-guiding system preferably has a first duct, which conducts an air stream in the direction of a rotor blade tip, and a second duct, which conducts the air stream in the direction of the hub. The air stream that is conducted in the direction of the rotor blade tip is preferably an air stream that has been heated by the heating device. The air stream that is then conducted back is preferably a cooled air stream. The cooling arises in particular as a result of a release of heat to the rotor blade external material, in order to melt ice adhering thereto. Here, the ducts may preferably be of insulated form in sections in order that the least possible heat losses arise at locations at which the rotor blade does not necessarily have to be de-iced. It is preferable for the in particular
- 3 -heated air stream to flow along the inner wall of a rotor blade nose, specifically preferably in the front third of the rotor blade length, specifically in the region of the rotor blade tip.
A substantially closed air-guiding system is preferably provided. The air-guiding system ensures that the air situated in the system is conducted in the circuit such that cooled but still slightly heated recirculated air is heated again, whereby less heating power is required.
The air-guiding system has, in particular, the smallest possible volume in order to also keep the heating power as low as possible. For this purpose, provision is preferably made for those regions of the rotor blade which are at greater risk of icing to be heated in targeted fashion. These are in particular the nose region of the outer half or outer third of the rotor blade toward the rotor blade tip. It is preferable for substantially 40% of the outer part of the rotor blade toward the rotor blade tip to be heated. Furthermore, provision is preferably made for at least the warm-air supply, or a part of the warm-air supply, to be of insulated form.
It is preferable for an opening, which is in particular of predefinable size, to be provided on a pressure side of the fan, in particular for the continuous discharge of air out of the rotor blade de-icing device.
Through the provision of the opening, it is possible for a fraction of the air stream that is conducted in the circuit to be removed from the circuit. It is preferable for less than 10%, in particular less than 6%, in particular less than 4%, in particular less than 2%, of the amount of air conducted in the circuit to be removed from the circuit.
A substantially closed air-guiding system is preferably provided. The air-guiding system ensures that the air situated in the system is conducted in the circuit such that cooled but still slightly heated recirculated air is heated again, whereby less heating power is required.
The air-guiding system has, in particular, the smallest possible volume in order to also keep the heating power as low as possible. For this purpose, provision is preferably made for those regions of the rotor blade which are at greater risk of icing to be heated in targeted fashion. These are in particular the nose region of the outer half or outer third of the rotor blade toward the rotor blade tip. It is preferable for substantially 40% of the outer part of the rotor blade toward the rotor blade tip to be heated. Furthermore, provision is preferably made for at least the warm-air supply, or a part of the warm-air supply, to be of insulated form.
It is preferable for an opening, which is in particular of predefinable size, to be provided on a pressure side of the fan, in particular for the continuous discharge of air out of the rotor blade de-icing device.
Through the provision of the opening, it is possible for a fraction of the air stream that is conducted in the circuit to be removed from the circuit. It is preferable for less than 10%, in particular less than 6%, in particular less than 4%, in particular less than 2%, of the amount of air conducted in the circuit to be removed from the circuit.
- 4 -By means of this measure, a part of the air, including any gas released from the rotor blade, air moisture and any dust from the rotor blade, is blown out of the circuit. This firstly gives rise to a pressure reduction in the air circuit, and secondly, ice is also prevented from being able to accumulate within the rotor blade, for example at the rotary leadthrough.
The above measure is preferably enhanced in that, in a suction region of the air-guiding system in a rotor blade interior, there is provided an opening for the introduction of air from the rotor blade interior into the air-guiding system. Continuous purging of the rotor blade interior is made possible in this way.
In the context of the invention, a circuit is to be understood in particular to mean that air is conveyed from the rotor blade hub in the direction of the rotor blade tip and from the rotor blade tip back to the rotor blade hub again, before then being conducted to the rotor blade tip again, etc. In the case of such a substantially closed system, the residual heat of the air stream recirculated to the rotor blade hub, which preferably still has residual heat greater than the ambient heat, can be utilized further, such that highly efficient de-icing is possible. It is thus possible, for example, for air in a first duct, or an air stream in a first duct, to be conducted from a rotor blade root or rotor blade hub to the rotor blade tip, and, in the region of the rotor blade tip, proceeding for example from the middle of the rotor blade length, to be split up, in accordance with the air stream, into a component which is conducted further along the longitudinal axis toward the rotor blade tip and a component which is conducted transversely with respect thereto in order to conduct a warm air stream to the rotor blade nose. In the region of the rotor blade
The above measure is preferably enhanced in that, in a suction region of the air-guiding system in a rotor blade interior, there is provided an opening for the introduction of air from the rotor blade interior into the air-guiding system. Continuous purging of the rotor blade interior is made possible in this way.
In the context of the invention, a circuit is to be understood in particular to mean that air is conveyed from the rotor blade hub in the direction of the rotor blade tip and from the rotor blade tip back to the rotor blade hub again, before then being conducted to the rotor blade tip again, etc. In the case of such a substantially closed system, the residual heat of the air stream recirculated to the rotor blade hub, which preferably still has residual heat greater than the ambient heat, can be utilized further, such that highly efficient de-icing is possible. It is thus possible, for example, for air in a first duct, or an air stream in a first duct, to be conducted from a rotor blade root or rotor blade hub to the rotor blade tip, and, in the region of the rotor blade tip, proceeding for example from the middle of the rotor blade length, to be split up, in accordance with the air stream, into a component which is conducted further along the longitudinal axis toward the rotor blade tip and a component which is conducted transversely with respect thereto in order to conduct a warm air stream to the rotor blade nose. In the region of the rotor blade
- 5 -nose, where most ice accumulates, the warm air stream is cooled, and is correspondingly conveyed in cooled form from the rotor blade tip, or the region toward the rotor blade tip of the rotor blade, through a second duct in the direction of the rotor blade root again.
The conveyed air stream is thus conducted in the circuit in an air-guiding system. Said circuit also includes a fan and a heating device, for example in the form of a heating register.
In the context of the invention, a rotor blade nose is to be understood in particular to mean a blade leading edge.
It is preferable for fresh air to be added to the circuit. This also means in particular that fresh air is introduced into the circuit. The fresh air may be introduced for example from outside the rotor blade, in particular via the hub, or from the interior of the rotor blade. Provision may furthermore be made for the air supplied to the circuit to be filtered. In the context of the invention, fresh air is to be understood to mean fresh air added, from outside the air stream conducted in the circuit, to the air stream. Fresh air is preferably introduced into the rotor blade from outside the rotor blades, in particular via the hub.
It is preferable for an opening through which fresh air can be introduced into the rotor blade interior to be provided in a partition of the rotor blade. A
corresponding filter is preferably provided in order to filter the fresh air before it is introduced into the rotor blade.
Some of the provided openings, or all of the provided openings, may preferably be closable and/or adjustable in terms of their diameter. This is preferably realized
The conveyed air stream is thus conducted in the circuit in an air-guiding system. Said circuit also includes a fan and a heating device, for example in the form of a heating register.
In the context of the invention, a rotor blade nose is to be understood in particular to mean a blade leading edge.
It is preferable for fresh air to be added to the circuit. This also means in particular that fresh air is introduced into the circuit. The fresh air may be introduced for example from outside the rotor blade, in particular via the hub, or from the interior of the rotor blade. Provision may furthermore be made for the air supplied to the circuit to be filtered. In the context of the invention, fresh air is to be understood to mean fresh air added, from outside the air stream conducted in the circuit, to the air stream. Fresh air is preferably introduced into the rotor blade from outside the rotor blades, in particular via the hub.
It is preferable for an opening through which fresh air can be introduced into the rotor blade interior to be provided in a partition of the rotor blade. A
corresponding filter is preferably provided in order to filter the fresh air before it is introduced into the rotor blade.
Some of the provided openings, or all of the provided openings, may preferably be closable and/or adjustable in terms of their diameter. This is preferably realized
- 6 -during the operation of the method for de-icing the rotor blade.
Through the provision of a further opening in a partition of the rotor blade and the introduction of fresh air, the concentration of gases that are harmful to health in the blade interior can be continuously reduced.
It is preferable for a first air filter to be provided in the first duct and/or for a second air filter to be provided in the second duct. This prevents dust particles in the interior of the rotor blade, which dust particles were created during the production of the rotor blade or during operation or are possibly still being created, from being deposited on heating elements of the heating device, whereby the risk of fire or explosion upon activation of the heating device is eliminated. Furthermore, mechanical protection for the heating elements, for example, can be realized in this way. The heating device is preferably a heating register.
The amount of fresh air introduced into the circuit, in particular during the method for de-icing a rotor blade, is preferably adjustable.
A refinement of the method is particularly preferable in which, before and/or after the heating of the air stream by means of the heating device, the air stream is conducted in the circuit in particular for a predefinable time. This means in particular that the air stream is conducted in the circuit without the supply of further heating energy. Efficient dehumidification of the system is realized in this way.
Said method step is preferably performed with corresponding partial deaeration, that is to say a discharge of a fraction of the air stream conducted in
Through the provision of a further opening in a partition of the rotor blade and the introduction of fresh air, the concentration of gases that are harmful to health in the blade interior can be continuously reduced.
It is preferable for a first air filter to be provided in the first duct and/or for a second air filter to be provided in the second duct. This prevents dust particles in the interior of the rotor blade, which dust particles were created during the production of the rotor blade or during operation or are possibly still being created, from being deposited on heating elements of the heating device, whereby the risk of fire or explosion upon activation of the heating device is eliminated. Furthermore, mechanical protection for the heating elements, for example, can be realized in this way. The heating device is preferably a heating register.
The amount of fresh air introduced into the circuit, in particular during the method for de-icing a rotor blade, is preferably adjustable.
A refinement of the method is particularly preferable in which, before and/or after the heating of the air stream by means of the heating device, the air stream is conducted in the circuit in particular for a predefinable time. This means in particular that the air stream is conducted in the circuit without the supply of further heating energy. Efficient dehumidification of the system is realized in this way.
Said method step is preferably performed with corresponding partial deaeration, that is to say a discharge of a fraction of the air stream conducted in
- 7 -the circuit out of the circuit, and possibly additional, in particular active, aeration or addition of fresh air to the circuit. A dehumidification is efficient in particular if the air stream continues to be conducted in the circuit after heating of the air stream. This is because heated air can absorb a greater amount of air moisture, and furthermore, water or molten ice deposits can be removed from the air-guiding system.
It is preferable if, before the heating of the air stream, temperature sensors arranged in the air stream are checked with regard to functionality. Here, it is assumed in particular that the air stream, before the heating of the air stream, leads to a constant uniform temperature in the entire air-guiding system, in particular if the air stream has been conducted through the circuit multiple times. In this way, it is then possible for the temperature sensors to be checked with regard to plausibility. Said temperature sensors should specifically measure substantially the same temperature if the sensors are working correctly. The check of the functionality of the temperature sensors is thus preferably performed after the non-heated air stream has been conducted through the circuit for a predefinable time.
The method for de-icing the rotor blade is preferably performed while the rotor blade is arranged leeward of a tower of the wind turbine. In this way, damage to the wind turbine as a result of falling ice is prevented.
This is performed in particular in the presence of a corresponding wind strength, which is predefinable. The method for de-icing the rotor blade is preferably performed only above a predefinable wind strength.
The rotor blade position during the de-icing process is preferably such that the blade leading edge is arranged
It is preferable if, before the heating of the air stream, temperature sensors arranged in the air stream are checked with regard to functionality. Here, it is assumed in particular that the air stream, before the heating of the air stream, leads to a constant uniform temperature in the entire air-guiding system, in particular if the air stream has been conducted through the circuit multiple times. In this way, it is then possible for the temperature sensors to be checked with regard to plausibility. Said temperature sensors should specifically measure substantially the same temperature if the sensors are working correctly. The check of the functionality of the temperature sensors is thus preferably performed after the non-heated air stream has been conducted through the circuit for a predefinable time.
The method for de-icing the rotor blade is preferably performed while the rotor blade is arranged leeward of a tower of the wind turbine. In this way, damage to the wind turbine as a result of falling ice is prevented.
This is performed in particular in the presence of a corresponding wind strength, which is predefinable. The method for de-icing the rotor blade is preferably performed only above a predefinable wind strength.
The rotor blade position during the de-icing process is preferably such that the blade leading edge is arranged
- 8 -leeward. In this way, the heated blade leading edge is turned out of the wind, which leads to more efficient and faster de-icing.
It is preferable for the rotor blade or the rotor with the corresponding rotor blades to track the wind direction, such that, during the de-icing process, the rotor blade is in any case arranged leeward of the tower of the wind turbine.
A rotor of the wind turbine, comprising at least three rotor blades, is preferably positioned such that at least two rotor blades point downward or are arranged below the horizontal, wherein an angular adjustment of at least one rotor blade is performed in order to substantially maintain the position of the rotor. It is ensured in this way that the two rotor blades which are to be de-iced possibly simultaneously or at least partially in succession also continue to point downward during the de-icing process, such that ice which falls off does not damage the wind turbine. In the case of a wind turbine having two blades, a rotor blade that is to be de-iced can point downward, or alternatively, it is possible for the rotor blades to be arranged in the horizontal and for one or both rotor blades to be de-iced. Correspondingly, in the case of wind turbines having more than three rotor blades, the rotor blades to be de-iced should, during the de-icing process, be arranged in the horizontal or below the horizontal.
The method is highly efficient if two rotor blades are de-iced such that, after the de-icing of a first rotor blade, a heated air stream is conducted out of the first rotor blade into a second rotor blade.
It is preferably the case that, before the introduction of the heated air stream into the second rotor blade, a non-heated air stream is conducted in the second rotor
It is preferable for the rotor blade or the rotor with the corresponding rotor blades to track the wind direction, such that, during the de-icing process, the rotor blade is in any case arranged leeward of the tower of the wind turbine.
A rotor of the wind turbine, comprising at least three rotor blades, is preferably positioned such that at least two rotor blades point downward or are arranged below the horizontal, wherein an angular adjustment of at least one rotor blade is performed in order to substantially maintain the position of the rotor. It is ensured in this way that the two rotor blades which are to be de-iced possibly simultaneously or at least partially in succession also continue to point downward during the de-icing process, such that ice which falls off does not damage the wind turbine. In the case of a wind turbine having two blades, a rotor blade that is to be de-iced can point downward, or alternatively, it is possible for the rotor blades to be arranged in the horizontal and for one or both rotor blades to be de-iced. Correspondingly, in the case of wind turbines having more than three rotor blades, the rotor blades to be de-iced should, during the de-icing process, be arranged in the horizontal or below the horizontal.
The method is highly efficient if two rotor blades are de-iced such that, after the de-icing of a first rotor blade, a heated air stream is conducted out of the first rotor blade into a second rotor blade.
It is preferably the case that, before the introduction of the heated air stream into the second rotor blade, a non-heated air stream is conducted in the second rotor
- 9 -blade in the circuit via a further air-guiding system, and a fraction of the air stream that is conducted in the circuit is removed from the circuit. This preferably also serves for the calibration or checking of the functionality of the temperature sensors in the second rotor blade and/or for the dehumidification of the air contained in the rotor blade. The corresponding measures that have been performed in the first rotor blade or in the rotor blade as described above may also be performed in the second rotor blade for de-icing said rotor blade.
The duration of the de-icing process and/or the amount of heat supplied are/is preferably predefined in a manner dependent on at least one detected starting condition. In the context of the invention, a starting condition is to be understood in particular to mean a temperature of the air stream in the interior of the rotor blade, in particular in the air-guiding system.
The temperature during the conducting of the air stream in the circuit preferably means the temperature without the air stream being heated, wherein the air stream is conducted in the circuit for a predefinable time.
Furthermore, a wind speed, a wind direction, an ambient temperature and/or an air humidity may be understood as starting conditions. The duration of the de-icing process and/or the supplied amount of heat are/is preferably predefined in a manner dependent on multiple detected starting conditions.
It is preferably the case that, during the heating of the air stream, closed-loop control of the temperature in the feed line, in particular in the heating device, is performed. In this way, for a system-limited maximum power, highly efficient and fast de-icing can be performed.
The duration of the de-icing process and/or the amount of heat supplied are/is preferably predefined in a manner dependent on at least one detected starting condition. In the context of the invention, a starting condition is to be understood in particular to mean a temperature of the air stream in the interior of the rotor blade, in particular in the air-guiding system.
The temperature during the conducting of the air stream in the circuit preferably means the temperature without the air stream being heated, wherein the air stream is conducted in the circuit for a predefinable time.
Furthermore, a wind speed, a wind direction, an ambient temperature and/or an air humidity may be understood as starting conditions. The duration of the de-icing process and/or the supplied amount of heat are/is preferably predefined in a manner dependent on multiple detected starting conditions.
It is preferably the case that, during the heating of the air stream, closed-loop control of the temperature in the feed line, in particular in the heating device, is performed. In this way, for a system-limited maximum power, highly efficient and fast de-icing can be performed.
- 10 -The air stream is preferably dehumidified by way of an additional dehumidification device. For example, for this purpose, a cooled surface may be provided on which air moisture condenses, which air moisture is then correspondingly discharged from the system and from the wind turbine.
To be able to thaw and shed ice adhering to rotor blades, those surfaces of the rotor blades which are to be de-iced are heated to a temperature higher than 0 C.
The heat energy required for this purpose, and the air stream required, are provided by preferably in each case one rotor blade de-icing device per rotor blade.
Here, a heating device and a fan are provided, preferably in the form of a fan-heater unit, which is arranged within a blade root of the rotor blade and fastened to the rotor hub.
In particular, the fan-heater unit comprises a fan, a heating device, for example a heating register, and a concentric double pipe in the form of a first and a second duct for the feed and return of the air in the air-guiding system. A counterpart to the concentric double pipe is preferably provided, which counterpart co-rotates with the rotor blade during the pitch adjustment. The counterpart of the rotor blade and the concentric double pipe of the fan-heater unit are preferably connected to one another by way of a rotary leadthrough.
By way of an open-loop and closed-loop controller, which is preferably provided externally with respect to the fan-heater unit, the heating device and the fan are actuated and preferably also monitored. The air-guiding system or the ventilation system in each rotor blade is, in terms of basic principle, a closed system, wherein provision may be made for small amounts of air to be exchanged or replaced. In this way, the residual
To be able to thaw and shed ice adhering to rotor blades, those surfaces of the rotor blades which are to be de-iced are heated to a temperature higher than 0 C.
The heat energy required for this purpose, and the air stream required, are provided by preferably in each case one rotor blade de-icing device per rotor blade.
Here, a heating device and a fan are provided, preferably in the form of a fan-heater unit, which is arranged within a blade root of the rotor blade and fastened to the rotor hub.
In particular, the fan-heater unit comprises a fan, a heating device, for example a heating register, and a concentric double pipe in the form of a first and a second duct for the feed and return of the air in the air-guiding system. A counterpart to the concentric double pipe is preferably provided, which counterpart co-rotates with the rotor blade during the pitch adjustment. The counterpart of the rotor blade and the concentric double pipe of the fan-heater unit are preferably connected to one another by way of a rotary leadthrough.
By way of an open-loop and closed-loop controller, which is preferably provided externally with respect to the fan-heater unit, the heating device and the fan are actuated and preferably also monitored. The air-guiding system or the ventilation system in each rotor blade is, in terms of basic principle, a closed system, wherein provision may be made for small amounts of air to be exchanged or replaced. In this way, the residual
- 11 -heat in the return line during the rotor blade de-icing process is substantially maintained.
The air-guiding system preferably has a first duct, which is designed to conduct an air stream from the fan-heater unit in the region of the rotor blade root to the rotor blade tip, and a second duct, by means of which the air stream is conducted back from the rotor blade tip to the rotor blade root.
The air volume conducted in the circuit in the air-guiding system is preferably 6 m3 20 m3. A volume of 8 m3 to 12 m3 is particularly preferred. Said values apply preferably in the case of blade lengths of 50 m.
In one exemplary embodiment of the rotor blade de-icing device, between 800 m3/h and 2000 m3/h of air is conveyed in the circuit. It is preferable for approximately 20 m3/h to 100 m3/h of fresh air to be added. However, the invention is not restricted to these ranges. The stated ranges represent preferred embodiments.
The ratio of air conveyed in the circuit to freshly added air or fresh air is preferably between 20 and 40, particular preferably 25 to 30.
Owing to the fixed installation of the heating device and also of the fan or of the fan-heater unit on the hub, the electrical energy supply does not need to be led into the rotating part of the rotor blade, and furthermore, in this way, adequate lightning protection for the electrical energy supply and also for the open-loop control device can be ensured.
By means of the concentric double pipe, which is preferably positioned in the axis of rotation of the rotor blade, the warm feed air is blown via an appropriate counterpart into the duct system or the
The air-guiding system preferably has a first duct, which is designed to conduct an air stream from the fan-heater unit in the region of the rotor blade root to the rotor blade tip, and a second duct, by means of which the air stream is conducted back from the rotor blade tip to the rotor blade root.
The air volume conducted in the circuit in the air-guiding system is preferably 6 m3 20 m3. A volume of 8 m3 to 12 m3 is particularly preferred. Said values apply preferably in the case of blade lengths of 50 m.
In one exemplary embodiment of the rotor blade de-icing device, between 800 m3/h and 2000 m3/h of air is conveyed in the circuit. It is preferable for approximately 20 m3/h to 100 m3/h of fresh air to be added. However, the invention is not restricted to these ranges. The stated ranges represent preferred embodiments.
The ratio of air conveyed in the circuit to freshly added air or fresh air is preferably between 20 and 40, particular preferably 25 to 30.
Owing to the fixed installation of the heating device and also of the fan or of the fan-heater unit on the hub, the electrical energy supply does not need to be led into the rotating part of the rotor blade, and furthermore, in this way, adequate lightning protection for the electrical energy supply and also for the open-loop control device can be ensured.
By means of the concentric double pipe, which is preferably positioned in the axis of rotation of the rotor blade, the warm feed air is blown via an appropriate counterpart into the duct system or the
- 12 -air-guiding system of the rotor blade, and the cooled return line is led to the suction side of the fan again. By means of this circuit, the heating and fan power that is available can be utilized in an efficient manner.
The components of the air guide or of the air-guiding system are preferably partially of thermally insulated form. Furthermore, in the air circuit, that is to say in the air-guiding system, there may also be incorporated at least one further component which, for example, mechanically prevents a reversal of the defined air flow. Said component may be a non-return flap or a non-return valve.
The front blade chamber is preferably used at least partially as a return line in order to simplify the air-guiding system. Material can be saved in this way.
Nevertheless, in this case, the air volume that flows through is greater. Furthermore, then, the pressure losses in the circuit system or in the air-guiding system are reduced, whereby the volume flow increases and the return line temperature increases, specifically in the case of an unchanged feed line temperature. This can improve the heat transfer conditions.
By means of an in particular passive admixing of ambient air, different method implementations are possible. Here, local releases of gas in the system or from the rotor blade material can be homogenized and diluted with ambient air. It is preferably possible for active ambient air admixing to be performed, wherein here, flap open-loop control is provided actively and in accordance with demand, by means of which the amount of ambient air that is admixed can be adjusted.
The components of the air guide or of the air-guiding system are preferably partially of thermally insulated form. Furthermore, in the air circuit, that is to say in the air-guiding system, there may also be incorporated at least one further component which, for example, mechanically prevents a reversal of the defined air flow. Said component may be a non-return flap or a non-return valve.
The front blade chamber is preferably used at least partially as a return line in order to simplify the air-guiding system. Material can be saved in this way.
Nevertheless, in this case, the air volume that flows through is greater. Furthermore, then, the pressure losses in the circuit system or in the air-guiding system are reduced, whereby the volume flow increases and the return line temperature increases, specifically in the case of an unchanged feed line temperature. This can improve the heat transfer conditions.
By means of an in particular passive admixing of ambient air, different method implementations are possible. Here, local releases of gas in the system or from the rotor blade material can be homogenized and diluted with ambient air. It is preferably possible for active ambient air admixing to be performed, wherein here, flap open-loop control is provided actively and in accordance with demand, by means of which the amount of ambient air that is admixed can be adjusted.
- 13 -Furthermore, dust accumulations can be supplied to corresponding filters, or partially released to the ambient air.
Furthermore, it is preferable for thermal homogenization of the air stream to take place in the circuit in particular before the heating of the air stream, such that sensors can be checked for plausibility, in particular temperature sensors can be checked for plausibility.
Furthermore, it is preferably the case that, after the ending of the de-icing process and a deactivation of a heating device, that is to say when there is no further supply of heat energy into the air stream, the air stream is preferably maintained in order to allow the heating device to cool to substantially homogenized system temperatures. In this way, it is preferably possible for the system, in particular the air-guiding system, to be correspondingly purged in order for any contained moisture to be discharged from the system. In this way, condensing of water in the air-guiding system, and in particular for example at a rotary leadthrough, is prevented, thus preventing the possibility of condensate freezing there and causing damage to components, for example during rotor blade adjustment processes.
The first rotor blade to be de-iced is preferably selected such that, after the ice has fallen off, an imbalance of the rotor that arises assists a rotation of the rotor in the desired manner.
An inclination sensor is preferably provided in order to permit rotor position detection. The inclination sensor is preferably arranged in a switchgear cabinet for the supply to and/or open-loop control of a rotor blade de-icing device.
Furthermore, it is preferable for thermal homogenization of the air stream to take place in the circuit in particular before the heating of the air stream, such that sensors can be checked for plausibility, in particular temperature sensors can be checked for plausibility.
Furthermore, it is preferably the case that, after the ending of the de-icing process and a deactivation of a heating device, that is to say when there is no further supply of heat energy into the air stream, the air stream is preferably maintained in order to allow the heating device to cool to substantially homogenized system temperatures. In this way, it is preferably possible for the system, in particular the air-guiding system, to be correspondingly purged in order for any contained moisture to be discharged from the system. In this way, condensing of water in the air-guiding system, and in particular for example at a rotary leadthrough, is prevented, thus preventing the possibility of condensate freezing there and causing damage to components, for example during rotor blade adjustment processes.
The first rotor blade to be de-iced is preferably selected such that, after the ice has fallen off, an imbalance of the rotor that arises assists a rotation of the rotor in the desired manner.
An inclination sensor is preferably provided in order to permit rotor position detection. The inclination sensor is preferably arranged in a switchgear cabinet for the supply to and/or open-loop control of a rotor blade de-icing device.
- 14 -The heating time and the amount of heat imparted are preferably defined in a manner dependent on a starting condition, such as for example the temperature of the air stream during the first purging process, the wind speed, the ambient temperature or the like. The heating time and the amount of heat imparted are preferably adapted in a manner dependent on a present return line temperature during the de-icing process. The heating time may vary for example between two and five hours.
Here, the amount of heat required for the de-icing process is preferably predefined, specifically on the basis of calculations or estimations based on the starting conditions. Furthermore, in this way, it is possible to set the minimum amount of supplied heating energy that should be used during the heating time.
It is preferable, for the adjustment of the rotor, for rotor position detection to be performed by way of an inclination sensor or multiple inclination sensors.
Said inclination sensor(s) may be installed in an open-loop control device which performs open-loop control of the de-icing process or of the de-icing method, and may thus be positionally fixed in relation to a rotor blade. It is preferable for a single open-loop control device to be provided, which is fixed relative to a rotor blade hub within a rotor blade. Said open-loop control device preferably serves for the open-loop control of the de-icing processes of all of the rotor blades.
A temperature measurement is preferably performed at different locations in the air stream. The temperature measurement values are made available to the open-loop control device, and open-loop control of the de-icing process is performed with the aid of the temperature measurement values. There are preferably further temperature measurement sensors for example in the
Here, the amount of heat required for the de-icing process is preferably predefined, specifically on the basis of calculations or estimations based on the starting conditions. Furthermore, in this way, it is possible to set the minimum amount of supplied heating energy that should be used during the heating time.
It is preferable, for the adjustment of the rotor, for rotor position detection to be performed by way of an inclination sensor or multiple inclination sensors.
Said inclination sensor(s) may be installed in an open-loop control device which performs open-loop control of the de-icing process or of the de-icing method, and may thus be positionally fixed in relation to a rotor blade. It is preferable for a single open-loop control device to be provided, which is fixed relative to a rotor blade hub within a rotor blade. Said open-loop control device preferably serves for the open-loop control of the de-icing processes of all of the rotor blades.
A temperature measurement is preferably performed at different locations in the air stream. The temperature measurement values are made available to the open-loop control device, and open-loop control of the de-icing process is performed with the aid of the temperature measurement values. There are preferably further temperature measurement sensors for example in the
- 15 -heating device and/or in the first duct, that is to say in the feed line, which further temperature measurement sensors ensure redundant load circuit deactivation.
Here, it may be provided that the temperature threshold value above which redundant load circuit deactivation is performed is higher than the temperature measurement value which, by way of the open-loop control device, leads for example to a deactivation of the heating device.
It is furthermore preferable for monitoring to be performed. In particular, it is checked whether the electrically supplied heating energy corresponds at least to the expected or pre-calculated amount of heat.
If this is not the case, it can for example be inferred that the air stream has not been conducted over the region in which it was intended to perform de-icing. In this case, a pipe fracture, for example, may exist.
Furthermore, it is preferable for plausibility monitoring of a return line temperature with regard to a maximum possible temperature and a minimum expected temperature after a heating phase to be performed. It is preferably possible for the power demand for the de-icing to be determined through the formation of a difference between feed line temperature and return line temperature, and for the determined power to be compared with the supplied power. It can also be checked in this way whether the de-icing method is functioning correctly.
Redundant load circuit deactivation is preferably provided. In the event of a corresponding fault, which may for example be an excessively high feed line temperature of over 65 C or over 50 C, wherein said temperature may be predefined, it is possible for the heating device to be deactivated by way of a redundant temperature sensor. The excessively high feed line
Here, it may be provided that the temperature threshold value above which redundant load circuit deactivation is performed is higher than the temperature measurement value which, by way of the open-loop control device, leads for example to a deactivation of the heating device.
It is furthermore preferable for monitoring to be performed. In particular, it is checked whether the electrically supplied heating energy corresponds at least to the expected or pre-calculated amount of heat.
If this is not the case, it can for example be inferred that the air stream has not been conducted over the region in which it was intended to perform de-icing. In this case, a pipe fracture, for example, may exist.
Furthermore, it is preferable for plausibility monitoring of a return line temperature with regard to a maximum possible temperature and a minimum expected temperature after a heating phase to be performed. It is preferably possible for the power demand for the de-icing to be determined through the formation of a difference between feed line temperature and return line temperature, and for the determined power to be compared with the supplied power. It can also be checked in this way whether the de-icing method is functioning correctly.
Redundant load circuit deactivation is preferably provided. In the event of a corresponding fault, which may for example be an excessively high feed line temperature of over 65 C or over 50 C, wherein said temperature may be predefined, it is possible for the heating device to be deactivated by way of a redundant temperature sensor. The excessively high feed line
- 16 -temperature preferably lies between 70 C and 85 C. The deactivation of the heating device is preferably performed in the event of a defect of the temperature sensor, which measures a feed line temperature of an open-loop control device for the open-loop control of the heating device and/or of the fan. The redundant sensor is a further temperature sensor which shuts off the heating device directly in the presence of an excessively high measurement value. For this purpose, a main switch can be correspondingly triggered. It is preferable, for this purpose, for the temperature threshold above which a direct shut-off of the heating device is provided to be higher than the temperature threshold set by way of the open-loop control device.
Furthermore, triggering of the main switch may be provided if a malfunction of the load circuit deactivation is identified. This is performed for example by way of a protective switch.
It is preferable for electronic load circuit relays to be used for optimum assistance of the feed line temperature closed-loop control and/or of the power splitting between a first rotor blade to be de-iced and a second rotor blade to be de-iced.
It is preferably provided that, during the heating or during the heating process, the feed line temperature is simulated and compared with the measured feed line temperature. The feed line temperature preferably has a PT1 characteristic.
Through the parallel or simultaneous simulation of the feed line temperature during the heating process and the comparison of the simulated and measured feed line temperatures, it is possible to identify different hardware or software faults, such as for example whether a filter is blocked or an air path is
Furthermore, triggering of the main switch may be provided if a malfunction of the load circuit deactivation is identified. This is performed for example by way of a protective switch.
It is preferable for electronic load circuit relays to be used for optimum assistance of the feed line temperature closed-loop control and/or of the power splitting between a first rotor blade to be de-iced and a second rotor blade to be de-iced.
It is preferably provided that, during the heating or during the heating process, the feed line temperature is simulated and compared with the measured feed line temperature. The feed line temperature preferably has a PT1 characteristic.
Through the parallel or simultaneous simulation of the feed line temperature during the heating process and the comparison of the simulated and measured feed line temperatures, it is possible to identify different hardware or software faults, such as for example whether a filter is blocked or an air path is
- 17 -constricted. Furthermore, it can be identified whether the fan power is too low or too high, or whether the air path or the ducts exhibit, for example, a pressure difference loss owing to a broken line. It is also possible to identify whether an excessive amount of heating energy has been introduced, for example as a result of a short circuit of an electrical load relay, or whether heating elements of the heating device are defective. The possible faults listed are mentioned merely by way of example.
With the supplied electrical power, in particular the measured inlet temperature and/or return line temperature into the fan-heater unit, and the system characteristics, which are determined substantially by the energy storage behaviour and thus by the transfer function, for example by way of the mass of the heating register or the heating device, a simulation of the feed line temperature is possible. With correspondingly accurately simulatable heating devices or fan-heater units, it may be possible to dispense with plausibility monitoring of the feed line temperature compared with the measured heating device temperature and/or to dispense with a determination of the power demand by forming the difference between feed line and return line temperature for a comparison of the determined powers with the supplied power.
It is preferable for the return line temperature to be measured and to monitor whether the latter lies within predefinable limits.
It is preferable for that fraction of the air stream which is removed from the circuit to be discharged between a fan and a heating device, wherein an opening or a purging air outlet is preferably provided.
With the supplied electrical power, in particular the measured inlet temperature and/or return line temperature into the fan-heater unit, and the system characteristics, which are determined substantially by the energy storage behaviour and thus by the transfer function, for example by way of the mass of the heating register or the heating device, a simulation of the feed line temperature is possible. With correspondingly accurately simulatable heating devices or fan-heater units, it may be possible to dispense with plausibility monitoring of the feed line temperature compared with the measured heating device temperature and/or to dispense with a determination of the power demand by forming the difference between feed line and return line temperature for a comparison of the determined powers with the supplied power.
It is preferable for the return line temperature to be measured and to monitor whether the latter lies within predefinable limits.
It is preferable for that fraction of the air stream which is removed from the circuit to be discharged between a fan and a heating device, wherein an opening or a purging air outlet is preferably provided.
- 18 -It is preferable for the air flow rate at the purging air outlet to be measured, wherein this is performed in particular during maintenance, preferably without heating of the air stream. The measurement value may then be compared with a predefined value, and rotor blade damage or air-guiding system damage can be inferred in the event of an excessively large deviation. Alternatively, a continuous air flow rate measurement at the purging air outlet may be provided in order to automatically detect faults.
Fault monitoring is furthermore possible by way of a differential pressure measurement, wherein expected pressure differences are dependent on the configurations of openings that are used and on the power of the fan.
It is preferably identified, on the basis of a pressure measurement in the rotor blade, whether the rotor blade is air-tight or whether those parts of the rotor blade which are supposed to be air-tight are in fact so. It is also possible, during times in which there is no risk of icing, for example when ambient temperatures are above freezing, for an air stream to be generated in order to check for damage, for example leaks, of the rotor blade.
It is preferable for the pressure of the air in the air-guiding system to be subject to open-loop control.
This may be realized by way of the fan power and/or the size of the openings for the inlet and outlet of the purging air. In the case of a negative pressure being generated in the rotor blade, no heated air can escape at undesired locations. This leads to efficient de-icing. Furthermore, in this way, it is possible to prevent system-critical rotor blade parts from being subjected to an excessively high feed line temperature over an excessively long period of time. Furthermore,
Fault monitoring is furthermore possible by way of a differential pressure measurement, wherein expected pressure differences are dependent on the configurations of openings that are used and on the power of the fan.
It is preferably identified, on the basis of a pressure measurement in the rotor blade, whether the rotor blade is air-tight or whether those parts of the rotor blade which are supposed to be air-tight are in fact so. It is also possible, during times in which there is no risk of icing, for example when ambient temperatures are above freezing, for an air stream to be generated in order to check for damage, for example leaks, of the rotor blade.
It is preferable for the pressure of the air in the air-guiding system to be subject to open-loop control.
This may be realized by way of the fan power and/or the size of the openings for the inlet and outlet of the purging air. In the case of a negative pressure being generated in the rotor blade, no heated air can escape at undesired locations. This leads to efficient de-icing. Furthermore, in this way, it is possible to prevent system-critical rotor blade parts from being subjected to an excessively high feed line temperature over an excessively long period of time. Furthermore,
- 19 -in this way, it is also possible for the feed line temperature to be increased, which reduces the de-icing duration.
Further features of the invention will become clear from the description of embodiments according to the invention together with the claims and the appended drawings. Embodiments according to the invention may satisfy individual features or a combination of multiple features. The preferred embodiments above and/or below may be advantageously combined with the above-stated individual features or solutions according to the invention.
The invention will be described below, without restriction of the general concept of the invention, on the basis of exemplary embodiments and with reference to the drawings, wherein, with regard to all details of the invention that are not discussed in any more detail in the text, reference is made explicitly to the drawings, in which:
figure 1 shows a schematic view of a wind turbine, figure 2 is a schematic illustration of a rotor blade on a hub, and figure 3 is a schematic illustration of a rotor blade de-icing device according to the invention.
In the drawings, identical or similar elements and/or parts are in each case denoted by the same reference designations, such that a repeated explanation will be omitted in each case.
Figure 1 schematically shows a wind turbine 1. The wind turbine 1 comprises a tower 2 on which there is provided a nacelle 3. Three rotor blades 5 are arranged
Further features of the invention will become clear from the description of embodiments according to the invention together with the claims and the appended drawings. Embodiments according to the invention may satisfy individual features or a combination of multiple features. The preferred embodiments above and/or below may be advantageously combined with the above-stated individual features or solutions according to the invention.
The invention will be described below, without restriction of the general concept of the invention, on the basis of exemplary embodiments and with reference to the drawings, wherein, with regard to all details of the invention that are not discussed in any more detail in the text, reference is made explicitly to the drawings, in which:
figure 1 shows a schematic view of a wind turbine, figure 2 is a schematic illustration of a rotor blade on a hub, and figure 3 is a schematic illustration of a rotor blade de-icing device according to the invention.
In the drawings, identical or similar elements and/or parts are in each case denoted by the same reference designations, such that a repeated explanation will be omitted in each case.
Figure 1 schematically shows a wind turbine 1. The wind turbine 1 comprises a tower 2 on which there is provided a nacelle 3. Three rotor blades 5 are arranged
- 20 -on a hub 4. The wind turbine is of horizontal-axis type. The horizontal axis simultaneously also constitutes the axis of rotation of the rotor 10, formed from the hub 4 and the rotor blades 5, of the wind turbine 1. In figure 1, the axis of rotation points substantially perpendicularly out of the plane of the drawing.
Each rotor blade 5 extends from a rotor blade root 6, which is arranged on the hub 4, to a rotor blade tip 45.
In the case of wind turbines 1 installed in cold regions with an atmosphere that gives rise to icing, accumulations of ice commonly occur on the rotor blade, specifically with such intensity that the performance of the installation is considerably reduced, which in the extreme case can lead to a shut-down of the installation. To ensure the operation of the wind turbine, provision is made for the rotor blades 5 to be de-iced by way of corresponding measures.
For this purpose, a rotor blade de-icing device of a wind turbine 1 is proposed, which rotor blade de-icing device, as schematically indicated in figure 2, conducts air or an air stream 13 substantially in a circuit in an air-guiding system 9, which air or air stream is heated in the vicinity of the hub 4 or in the vicinity of the rotor blade root or in the rotor blade root 6 and is conducted to the rotor blade tip 45 in a first duct 11. In the tip region of the rotor blade 5, the warm air passes into a second duct 12 which is arranged in the vicinity of the blade leading edge 7.
The first duct 11 is arranged further toward the trailing edge 8 of the rotor blade 5.
To conduct the heat energy to the locations at which the icing is most likely or most intense, the first
Each rotor blade 5 extends from a rotor blade root 6, which is arranged on the hub 4, to a rotor blade tip 45.
In the case of wind turbines 1 installed in cold regions with an atmosphere that gives rise to icing, accumulations of ice commonly occur on the rotor blade, specifically with such intensity that the performance of the installation is considerably reduced, which in the extreme case can lead to a shut-down of the installation. To ensure the operation of the wind turbine, provision is made for the rotor blades 5 to be de-iced by way of corresponding measures.
For this purpose, a rotor blade de-icing device of a wind turbine 1 is proposed, which rotor blade de-icing device, as schematically indicated in figure 2, conducts air or an air stream 13 substantially in a circuit in an air-guiding system 9, which air or air stream is heated in the vicinity of the hub 4 or in the vicinity of the rotor blade root or in the rotor blade root 6 and is conducted to the rotor blade tip 45 in a first duct 11. In the tip region of the rotor blade 5, the warm air passes into a second duct 12 which is arranged in the vicinity of the blade leading edge 7.
The first duct 11 is arranged further toward the trailing edge 8 of the rotor blade 5.
To conduct the heat energy to the locations at which the icing is most likely or most intense, the first
- 21 -duct 11 is equipped with insulation 16 so as to conduct the air stream 13 in the direction of the rotor blade tip 45 with the least possible heat losses. In the region of the rotor blade tip 45, the air stream 13 is, preferably by way of transverse flows 15, conducted in the direction of the rotor blade leading edge 7, around the blade leading edge, which exhibits the greatest icing tendency, specifically in particular that part of the rotor blade leading edge which is arranged toward the rotor blade tip 45. In this way, ice is correspondingly thawed and can fall off. The somewhat cooled air is conveyed, as a cooled air stream 14, back to the heater (not illustrated in figure 2). On the path to there, the second duct 12 is equipped with insulation 17 in order that the residual heat in the cooled air stream is not lost at locations where it does not need to be released.
Figure 3 schematically shows a rotor blade de-icing device of a wind turbine 1 according to the invention.
The rotor blade 5 is attached to the hub 4, which is merely indicated. Also connected positionally fixedly to the hub is a heating device 21, which may be in the form of a heating register, and the fan 22.
By means of the heating device 21 and the fan 22, warm air is conducted through the first duct 11, via the rotary leadthrough 25, in the direction of the rotor blade tip 45. The warm air is conducted onward, having been filtered by way of a filter 27, in the direction of the rotor blade tip 45. A corresponding air stream 13 is schematically indicated here. The arrows are intended to illustrate the warm-air flows which are conducted into a blade heating chamber 20 which is arranged at the rotor blade nose or rotor blade leading edge in the region of the rotor blade tip 45.
Figure 3 schematically shows a rotor blade de-icing device of a wind turbine 1 according to the invention.
The rotor blade 5 is attached to the hub 4, which is merely indicated. Also connected positionally fixedly to the hub is a heating device 21, which may be in the form of a heating register, and the fan 22.
By means of the heating device 21 and the fan 22, warm air is conducted through the first duct 11, via the rotary leadthrough 25, in the direction of the rotor blade tip 45. The warm air is conducted onward, having been filtered by way of a filter 27, in the direction of the rotor blade tip 45. A corresponding air stream 13 is schematically indicated here. The arrows are intended to illustrate the warm-air flows which are conducted into a blade heating chamber 20 which is arranged at the rotor blade nose or rotor blade leading edge in the region of the rotor blade tip 45.
- 22 -Cooled air 14 or a cooled air stream 14 passes back via an air filter 27' and the second duct 12 in the direction of the fan 22 via the rotary leadthrough 25.
The air stream that is conducted in the circuit comprises the air stream 13 and the air stream 14.
For corresponding open-loop or closed-loop control of the amounts of air and/or the amount of heat, multiple temperature sensors are provided. For example, the temperature sensor 32, which measures the temperature of the returned air, and the temperature sensors 33 and 34. The temperature sensor 34 measures the heating device temperature or the heating register temperature, and the temperature sensor 33 measures the feed line temperature. The feed line temperature is the temperature prevailing immediately downstream of the heating device as viewed in the flow direction of the air stream. The measurement values of the sensors 32, 33 and 34 are provided to an open-loop control unit 44 (not illustrated) for the open-loop and/or closed-loop control of the heating device 21 and the fan 22.
As a safety measure, there is also provided a temperature sensor 35 which, for example in the presence of an excessively high feed line temperature, can directly shut off the heating device 21.
Correspondingly, the heating device can also be shut off by way of the temperature sensor 36, by means of which the heating device temperature is measured.
Furthermore, on the pressure side of the fan 22, there is provided a small opening 23 via which a small volume flow of the air that is conducted in the circuit can be discharged via an air line or a purging air line 24.
Furthermore, an opening 28 may be provided on the suction side of the air-guiding system 9 or at the inlet side of the filter 27' in order to draw off air
The air stream that is conducted in the circuit comprises the air stream 13 and the air stream 14.
For corresponding open-loop or closed-loop control of the amounts of air and/or the amount of heat, multiple temperature sensors are provided. For example, the temperature sensor 32, which measures the temperature of the returned air, and the temperature sensors 33 and 34. The temperature sensor 34 measures the heating device temperature or the heating register temperature, and the temperature sensor 33 measures the feed line temperature. The feed line temperature is the temperature prevailing immediately downstream of the heating device as viewed in the flow direction of the air stream. The measurement values of the sensors 32, 33 and 34 are provided to an open-loop control unit 44 (not illustrated) for the open-loop and/or closed-loop control of the heating device 21 and the fan 22.
As a safety measure, there is also provided a temperature sensor 35 which, for example in the presence of an excessively high feed line temperature, can directly shut off the heating device 21.
Correspondingly, the heating device can also be shut off by way of the temperature sensor 36, by means of which the heating device temperature is measured.
Furthermore, on the pressure side of the fan 22, there is provided a small opening 23 via which a small volume flow of the air that is conducted in the circuit can be discharged via an air line or a purging air line 24.
Furthermore, an opening 28 may be provided on the suction side of the air-guiding system 9 or at the inlet side of the filter 27' in order to draw off air
- 23 -from the rotor blade interior and thus permit a removal of undesired gases from the rotor blade interior.
The system may for example be operated with a negative pressure overall.
Furthermore, in the partition 26 in which the rotary leadthrough 25 is arranged, there may be provided an opening 31 via which fresh air, which passes into the rotor blade interior for example via the hub 40, passes, having been filtered by way of a filter 30, into the rotor blade interior to the left of the partition 26 in figure 3. Permanent purging is ensured in this way.
By means of the illustrated features from figure 3, the method for de-icing a rotor blade of a wind turbine can be implemented in an efficient manner. It is optionally also possible for a dehumidifier 50 to be provided in order to dehumidify the air stream 13 that is conducted in the circuit in the air-guiding system. Said dehumidifier may for example be a cooling device which cools the duct 11 over a certain distance, wherein the condensate is collected and removed from the rotor blade, for example by way of a pump or by gravity, via a hose (not illustrated).
Furthermore, it may be provided that the inlet and outlet openings by means of which a fraction of the air stream 13 that is conducted in the circuit is removed from the circuit, or fresh air can be supplied, is of variable cross section or even closable. In this way, it is possible for the flow rate of the air stream 13 conducted out of the circuit, and/or the flow rate of the fresh air introduced into the circuit, to be adjusted in targeted fashion during operation.
The system may for example be operated with a negative pressure overall.
Furthermore, in the partition 26 in which the rotary leadthrough 25 is arranged, there may be provided an opening 31 via which fresh air, which passes into the rotor blade interior for example via the hub 40, passes, having been filtered by way of a filter 30, into the rotor blade interior to the left of the partition 26 in figure 3. Permanent purging is ensured in this way.
By means of the illustrated features from figure 3, the method for de-icing a rotor blade of a wind turbine can be implemented in an efficient manner. It is optionally also possible for a dehumidifier 50 to be provided in order to dehumidify the air stream 13 that is conducted in the circuit in the air-guiding system. Said dehumidifier may for example be a cooling device which cools the duct 11 over a certain distance, wherein the condensate is collected and removed from the rotor blade, for example by way of a pump or by gravity, via a hose (not illustrated).
Furthermore, it may be provided that the inlet and outlet openings by means of which a fraction of the air stream 13 that is conducted in the circuit is removed from the circuit, or fresh air can be supplied, is of variable cross section or even closable. In this way, it is possible for the flow rate of the air stream 13 conducted out of the circuit, and/or the flow rate of the fresh air introduced into the circuit, to be adjusted in targeted fashion during operation.
- 24 -It is preferable for warm exit air that is removed from the circuit to be directed toward a pitching gearbox or a drive system of the rotor blade.
All of the stated features, even the features that emerge only from the drawings and also individual features that are disclosed in combination with other features, are regarded as being essential to the invention individually and in combination. Embodiments according to the invention may be satisfied by individual features or a combination of multiple features. In the context of the invention, features referred to using "in particular" or "preferably" are to be understood as optional features.
All of the stated features, even the features that emerge only from the drawings and also individual features that are disclosed in combination with other features, are regarded as being essential to the invention individually and in combination. Embodiments according to the invention may be satisfied by individual features or a combination of multiple features. In the context of the invention, features referred to using "in particular" or "preferably" are to be understood as optional features.
- 25 -List of reference designations 1 Wind turbine 2 Tower 3 Nacelle 4 Hub 5 Rotor blade 6 Rotor blade root 7 Blade leading edge 8 Blade trailing edge 9 Air-guiding system 10 Rotor 11 First duct 12 Second duct 13 Air stream 14 Cooled air stream 15 Transverse flow 16 Insulation 17 Insulation 20 Blade heating chamber 21 Heating device 22 Fan 23 Opening, pressure side 24 Purging air line 25 Rotary leadthrough
26 Partition
27, 27' Filter
28 Opening, suction side Filter 30 31 Opening, blade partition 32 Temperature sensor 33 Temperature sensor 34 Temperature sensor Temperature sensor with hardware deactivation 35 36 Temperature sensor with hardware deactivation 37 Bracket 38 Rotor blade interior Hub connection 45 Rotor blade tip 46 Axis of rotation 50 Dehumidifier
Claims (11)
1. Method for de-icing a rotor blade (5) of a wind turbine (1), wherein an air stream (13, 14) is conducted through the rotor blade (5) by way of a fan (22), wherein the air stream (13, 14) is conducted in a circuit by way of an air-guiding system (9) and, furthermore, the air stream (13, 14) is heated by way of a heating device (21), characterized in that a fraction of the air stream (13, 14) that is conducted in the circuit is removed from the circuit.
2. Method according to Claim 1, characterized in that fresh air is added to the circuit.
3. Method according to Claim 1 or 2, characterized in that, before and/or after the heating of the air stream (13, 14) by means of the heating device (21), the air stream (13, 14) is conducted in the circuit in particular for a predefinable time.
4. Method according to Claim 3, characterized in that, before the heating of the air stream (13, 14), temperature sensors (32 - 36) arranged in the air stream (13, 14) are checked with regard to functionality.
5. Method according to one of Claims 1 to 4, characterized in that the method for de-icing the rotor blade (5) is performed while the rotor blade (5) is arranged leeward of a tower (2) of the wind turbine (1).
6. Method according to one of Claims 1 to 5, characterized in that a rotor (10) of the wind turbine (1), comprising at least three rotor blades (5), is positioned such that two rotor blades (5) point downward, wherein an angular adjustment of at least one rotor blade (5) is performed in order to substantially maintain the position of the rotor (10).
7. Method according to one of Claims 1 to 6, characterized in that two rotor blades (5) are de-iced such that, after the de-icing of a first rotor blade (5), a heated air stream (13, 14) is conducted out of the first rotor blade (5) into a second rotor blade (5).
8. Method according to Claim 7, characterized in that, before the introduction of the heated air stream (13, 14) into the second rotor blade (5), a non-heated air stream (13, 14) is conducted in the second rotor blade (5) in the circuit via a further air-guiding system (9), and a fraction of the air stream (13, 14) that is conducted in the circuit is removed from the circuit.
9. Method according to one of Claims 1 to 8, characterized in that the duration of the de-icing process and/or the amount of heat supplied are/is predefined in a manner dependent on at least one detected starting condition.
10. Method according to one of Claims 1 to 9, characterized in that, during the heating of the air stream (13, 14), closed-loop control of the temperature in the feed line, in particular in the heating device (21), is performed.
11. Method according to one of Claims 1 to 10, characterized in that the air stream (13, 14) is dehumidified by way of an additional dehumidification device (50).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102015000636.3A DE102015000636A1 (en) | 2015-01-22 | 2015-01-22 | Method for deicing a rotor blade of a wind energy plant |
| DE102015000636.3 | 2015-01-22 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2916779A1 true CA2916779A1 (en) | 2016-07-22 |
| CA2916779C CA2916779C (en) | 2018-09-18 |
Family
ID=55066534
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2916779A Expired - Fee Related CA2916779C (en) | 2015-01-22 | 2016-01-06 | Method for de-icing a rotor blade of a wind turbine |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP3048296A1 (en) |
| CA (1) | CA2916779C (en) |
| DE (1) | DE102015000636A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107882692A (en) * | 2016-09-30 | 2018-04-06 | 西门子公司 | The damage check of the rotor blade of wind turbine |
| CN110131864A (en) * | 2019-06-18 | 2019-08-16 | 国电联合动力技术有限公司 | Intelligent temperature regulating system and adjusting method in a kind of wind electricity blade manufacturing process |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA3017775C (en) | 2016-03-31 | 2020-08-25 | Vestas Wind Systems A/S | Controlling heating elements in a wind turbine system |
| CN110242512B (en) * | 2019-07-16 | 2021-05-11 | 株洲时代新材料科技股份有限公司 | Wind power blade deicing system, application method thereof and wind generating set |
| CN112780509B (en) * | 2019-11-01 | 2023-07-28 | 新疆金风科技股份有限公司 | Air cooling system, wind generating set and cooling method thereof |
| CN111237139A (en) * | 2019-12-09 | 2020-06-05 | 苏州思曼特自动化科技有限公司 | Blade deicing system and method |
| EP4303436A1 (en) * | 2022-07-04 | 2024-01-10 | Wobben Properties GmbH | Wind turbine blade rotor blade and wind turbine |
| EP4306797A1 (en) | 2022-07-12 | 2024-01-17 | Wobben Properties GmbH | Wind turbine blade rotor blade and wind turbine |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE9112945U1 (en) * | 1991-10-17 | 1991-12-05 | Aurora Konrad G. Schulz Gmbh & Co, 6933 Mudau | Ventilation and heating device |
| DE19621485A1 (en) * | 1996-05-29 | 1998-03-12 | Schulte Franz Josef | Warm air heating device for preventing icing-up of rotor blades of wind power plant |
| ES2371988T3 (en) * | 2007-10-05 | 2012-01-12 | Vestas Wind Systems A/S | DEVELOPMENT PROCEDURE OF A SHOVEL OF A WIND TURBINE, A WIND TURBINE AND USE OF THE SAME. |
| DE102010030472A1 (en) | 2010-06-24 | 2011-12-29 | Repower Systems Ag | Rotorblattenteisung |
| DE102011086603A1 (en) * | 2011-11-17 | 2013-05-23 | Wobben Properties Gmbh | Wind turbine rotor blade and method for defrosting a wind turbine rotor blade |
-
2015
- 2015-01-22 DE DE102015000636.3A patent/DE102015000636A1/en not_active Withdrawn
-
2016
- 2016-01-04 EP EP16150031.9A patent/EP3048296A1/en not_active Withdrawn
- 2016-01-06 CA CA2916779A patent/CA2916779C/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107882692A (en) * | 2016-09-30 | 2018-04-06 | 西门子公司 | The damage check of the rotor blade of wind turbine |
| CN110131864A (en) * | 2019-06-18 | 2019-08-16 | 国电联合动力技术有限公司 | Intelligent temperature regulating system and adjusting method in a kind of wind electricity blade manufacturing process |
Also Published As
| Publication number | Publication date |
|---|---|
| CA2916779C (en) | 2018-09-18 |
| EP3048296A1 (en) | 2016-07-27 |
| DE102015000636A1 (en) | 2016-07-28 |
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