NL2022584B1 - System for on-site maintenance of a turbine blade of a land or sea-based wind turbine, and method of using such a system for performing maintenance - Google Patents

Abstract

The present invention relates to a system for on-site maintenance of a turbine blade of a land- or sea-based wind turbine, comprising: - a land- or sea-based carrier that is arrangeable near the wind turbine; - a maintenance device, comprising an enclosure that is configured to at least partly enclose a part of the turbine blade of said wind turbine; and - an actuator that is arrangeable on said carrier supporting the enclosure and configured to extend the enclosure upward from said carrier along the turbine blade. The invention further relates to a method of performing on-site maintenance to a turbine blade of a land- or sea-based wind turbine with a maintenance system according to any of the foregoing claims, comprising the steps of: - arranging the carrier near the wind turbine; - supporting the enclosure from the carrier; - fixing the wind turbine against rotation; and - using the actuator to move the enclosure upward from said carrier along the turbine blade to at least partly enclose a part of the turbine blade of said wind turbine.

Description

System for on-site maintenance of a turbine blade of a land or sea-based wind turbine, and method of using such a system for performing maintenance The present invention relates to a system for on-site maintenance of a turbine blade of a land or sea-based wind turbine. The invention is further related to a method of performing on- site maintenance to a turbine blade of a land or sea-based wind turbine with such a maintenance system.

Maintenance may comprise preventive maintenance and break down maintenance and repairs works, possibly immediately following an inspection.

Maintenance issues with respect to wind turbine blades may be related to many factors, but are often associated with leading-edge erosion and impact damage. The tips speeds of a wind turbine blade may be well above 300 km/h. At these speeds, rain drops can take on the impact of small stones, while blowing sand may have a significant erosion power. Erosion of the wind turbine blades causes a blade roughness, and debris may accumulate on the wind turbine blades over time. They both negatively affect the performance of the wind turbine. Moreover, wind turbine blades that require maintenance may create a vibration that contributes to gearbox wear and failures.

During maintenance of a wind turbine blade, maintenance personnel ascends inside the tower to the nacelle, from where they climb on the nacelle and descend downwards along the blades using rope suspension, also called rope access, Wind turbines are getting bigger and bigger, and the largest wind turbine in 2018 is the MHI Vestas V164-9.5, which has a blade length of 80 m and a tower of 105 m. For maintenance on this type of wind turbine, the maintenance personnel is thus suspended by ropes of up to 80 m long. As maintenance work is performed at a relatively high altitude, while wind turbines are — by nature — preferably arranged at windy locations, also the maintenance personnel is exposed to severe winds. Moreover, adverse weather conditions often prevent maintenance work to be carried out and significantly reduce the season at which maintenance work can be performed.

An object of the present invention is to provide a system for on-site maintenance of a turbine blade of a land or sea-based wind turbine, that is improved relative to the prior art and wherein at least one of the above stated problems is obviated.

Said object is achieved with the system for on-site maintenance of a turbine blade of a land- or sea-based wind turbine according to claim 1 or the present invention, said system comprising: - a land- or sea-based carrier that is arrangeable near the wind turbine; - a maintenance device, comprising an enclosure that is configured to at least partly enclose a part of the turbine blade of said wind turbine; and

- an actuator that is arrangeable on said carrier supporting the enclosure and configured to extend the enclosure upward from said carrier along the turbine blade.

The enclosure is extended upward from the land- or sea-based carrier that is arrangeable near the wind turbine, thereby providing a number of advantages relative to the rope- suspended maintenance as described above.

First of all, maintenance personnel may perform maintenance work from said enclosure that is far more stable than a rope suspension, also allowing maintenance work to be executed all year round in a safe and comfortable manner. This also contributes to high quality repair work that is not negatively influenced by weather conditions outside the enclosure.

Secondly, the enclosure may shield the maintenance personnel from adverse weather conditions, further contributing to safety and comfort of the maintenance personnel.

Thirdly, the system for on-site maintenance according to the invention is relatively casy and fast to set up, preventing the need for ascending via the tower to the nacelle and successively descending from the nacelle along the turbine blades.

The invention further relates to a method of performing on-site maintenance to a turbine blade of a land- or sea-based wind turbine with a maintenance system according to any of the foregoing claims, comprising the steps of: - arranging the carrier near the wind turbine; - supporting the enclosure from the carrier; - fixing the wind turbine against rotation; and - using the actuator to move the enclosure upward from said carrier along the turbine blade to at least partly enclose a part of the turbine blade of said wind turbine.

Preferred embodiments are the subject of the dependent claims.

The various aspects and features described and shown in the specification can be applied, individually, wherever possible. These individual aspects, and in particular the aspects and features described in the attached dependent claims, may be made subject of divisional patent applications.

In the following description preferred embodiments of the present invention are further elucidated with reference to the drawing, in which: Figure 1 is a perspective view of a sea-based wind turbine and a maintenance system according to a first embodiment of the invention; Figures 2-4 are perspective views of successive steps of using the system of Figure 1; Figure 5 is a partially transparent perspective detail view of Figure 3; Figure 6 is a partially transparent perspective detail view of Figure 4;

Figure 7 is a perspective view of a maintenance system according to a second embodiment; Figure 8 is a perspective view of a maintenance system according to a third embodiment; Figure 9 is a perspective view of a maintenance system according to a fourth embodiment; and Figures 10A and 10B are perspective views of two states of a maintenance system according to a fifth embodiment.

All embodiments are related to a system 1 for on-site maintenance of a turbine blade 2 of a land- or sea-based wind turbine 3. In the shown embodiments, said system | comprises a sea-based carrier 4 that is arrangeable near the wind turbine 3. The sea-based carrier 4 may be a vessel or a barge. The sea-based carrier 4 may comprise or define an elevated platform. Preferably, the sea-based carrier 4 is a jack-up vessel. The skilled person will understand that the invention is not limited to sea-based wind turbines, and that the same principles may be applied to a land-based wind turbine.

The system 1 further comprises a maintenance device 5, comprising an enclosure 6 that is configured to at least partly enclose a part of the turbine blade 2 of said wind turbine 3, and an actuator 7 that is arrangeable on said carrier 4 supporting the enclosure and configured to extend the enclosure 6 upward from said carrier 4 along the turbine blade 2.

Figures 2-4 show successive steps of using the system for preparing and executing on-site maintenance of the turbine blade 2. The actuator 7 is configured to move said enclosure 6 between a transport state (Figure 2) onto the carrier 4 and a maintenance state (Figure 4) extending upward from said carrier 4 along the turbine blade 2. From the transport state in Figure 2, the actuator 7 first moves the enclosure 6 to extend outward relative from the carrier 4 — see arrow A in Figure 3. Simultaneously, the enclosure 6 may be opened - see arrows B in Figure 3. If necessary, a transverse positioning of the enclosure 6 in the direction of arrows E, and a pivoting of the enclosure 6 in the direction of arrow F around a pivot axis p, is possible to optimally align the enclosure 6 relative to a to be maintained turbine blade 2 (Figure 2).

Said enclosure 6 comprises a rigid elongate casing 8 configured to extend along a longitudinal direction of said turbine blade 2. Such an enclosure 6 makes it possible to guarantee optimal working conditions. For example, a {not shown) heating system may be applied to provide a temperature inside said enclosure, e.g. approximately 20 °C, that provides optimal working conditions and. A controlled environment results in higher quality of the maintenance and repair works of the turbine blades 2.

Said enclosure 6 preferably comprises two casing halves 9 that are moveable towards and away (arrow B in Figures 3 and 5) from each other, allowing the enclosure 6 to enclose a turbine blade 2 from a sideward direction.

After the enclosure 6 is positioned with the casing halves 9 on two opposite sides of the turbine blade 2, the casing halves 9 are moved in the direction of arrow C in Figures 4 and 5, while the height may be adjusted in the direction of arrows D in Figure 5.

In the shown embodiment, an upper wall 10 of said enclosure 6 comprises a passage opening 11 configured to allow passage of the turbine blade 2 into the enclosure 6. Said passage opening 11 may comprise a seal 12 that is configured to seal a space between the passage opening 11 and the turbine blade 3 during maintenance thereof. This seal 12 seals the inside of the enclosure 6 against weather conditions outside the enclosure 6.

The seal 12 is preferably also configured to provide a damper that is configured to reduce relative movement and/or vibrations between the enclosure 6 and the turbine blade 2. In practice, the (sea-based) carrier 4 may move. Also the wind turbine 3 may move, including the tower as a whole, but also the turbine blades 2 relative to the tower. After all, even when the turbine blades 2 are locked, a turbine blade 2 that is under maintenance may experience some movement as a result of resonance and vibrations. If the seal 12 is configured to provide a damper between the enclosure 6 and the turbine blade 2, any negative effects of a relative movement and/or vibrations between the enclosure 6 and the turbine blade 2 may be reduced.

In a preferred embodiment, said seal 12 is inflatable. An inflatable seal 12, such as an air seal, is very suitable to provide a sealing against weather conditions and to provide a damping action. Moreover, an inflatable seal 12 easily forms in correspondence to the specific dimensions and shape of the turbine blade 2 at the position of the passage opening 11. These dimensions and shape varies for different turbine blades 2, and moreover varies along the length of an individual turbine blade 2.

Preferably, a bottom wall 13 of said enclosure 6 comprises a further passage opening 14 configured to allow passage of the turbine blade 2 out of the enclosure 6. This would allow the enclosure to be moved along the turbine blade 2 for increasing the area that can be maintained from inside the enclosure 6.

The enclosure 6 comprises a plurality of internal platforms 15 that are vertically distributed. In the maintenance state of Figures 4 and 6, maintenance personnel may use the internal platforms 15 to safely and comfortably position themselves along the turbine blade 2 to perform maintenance work, while being protected from any adverse weather conditions.

Figure 7 shows a second embodiment, wherein the enclosure 6 comprises at least one internal platform 15 that is movable inside said enclosure 6 along a to be maintained turbineblade 2. This allows maintenance personnel to move along the turbine blade 2 in a comfortable and safe manner, while every area of the turbine blade 2 may be easily reached.

An improved stability of the system 1 may be obtained if the carrier 4 comprises a carrier-connector 16 that is configured to connect the carrier 4 to the wind turbine 3 (Figure 8).

5 Alternatively, the enclosure 6 may comprise an enclosure-connector 17 that is configured to connect the enclosure 6 to the wind turbine 3 (Figure 9). The enclosure-connector 17 may comprise two clamp halves 18a, 18b, each extending from a respective casing halve 9 of said enclosure 6.

In Figure 10A, a carrier-connector 16 and an enclosure-connector 17 are used in combination.

In the further embodiment of Figures 10A, 10B, the enclosure 6 is disengabable from the carrier 4 and configured to be temporarily connected to the wind turbine 3 as a stand- alone maintenance device 5. This would allow a single carrier 4, such as vessel 19, to transport a plurality of maintenance devices 5 to a wind park. At the wind park, the maintenance devices 5 may each be arranged on a dedicated wind turbine 3 for performing maintenance work to the turbine blades 2 thereof. Once maintenance work is finished for a specific wind turbine 3, the carrier 4 may engage the maintenance device 5 again to pick it up, after which it may be shipped by the carrier 4 to a further wind turbine 3 that requires maintenance. In this way, a single carrier 4 may be used to service a plurality of wind turbines 3 at a wind park at once, while providing a home base for the maintenance personnel during resting hours.

In an alternative embodiment of the system 1, it further comprises one or more than one motion sensor 20 configured to monitor a motion of said carrier 4 relative to said wind turbine 3, and a controller 21 configured to control the actuator 7 to actively counteract the motion of said carrier 4 relative to said wind turbine 3. Said motion sensor 20 and controller 21 are schematically indicated in Figure 4.

The invention further relates to a method of performing on-site maintenance to a turbine blade 2 of a (land- or) sea-based wind turbine 3 with a maintenance system 1 as described above, comprising the steps of: - arranging the carrier 4 near the wind turbine 3; - supporting the enclosure 6 from the carrier 4; - fixing the wind turbine 3 against rotation; and - using the actuator 7 to move the enclosure 6 upward from said carrier 4 along the turbine blade 2 to at least partly enclose a part of the turbine blade 2 of said wind turbine 3.

Preferably, the step of fixing the wind turbine 3 against rotation is preceded by the step of positioning the to be maintained turbine blade 2 in a substantially downward directed orientation.

The above described embodiment is intended only to illustrate the invention and not to limit in any way the scope of the invention.

Accordingly, it should be understood that where features mentioned in the appended claims are followed by reference signs, such signs are included solely for the purpose of enhancing the intelligibility of the claims and are in no way limiting on the scope of the claims.

The scope of the invention is defined solely by the following claims.

Claims (19)

Conclusions System for on-site maintenance of a turbine blade of a land- or sea-bound wind turbine, comprising: - a land- or sea-bound support that can be installed at the wind turbine; - a maintenance device, comprising a casing configured to at least partially encase a portion of the turbine blade of said wind turbine; and - an actuator disposable on said carrier supporting the casing and configured to extend the casing from said carrier upward along the turbine blade. The system of claim 1, wherein said actuator is configured to move said enclosure between a transport position on the carrier and a maintenance position extending upwardly from said carrier along the blade. A system according to any preceding claim, wherein said enclosure comprises a rigid elongated housing configured to extend along a longitudinal direction of said turbine blade. System according to any of the preceding claims, wherein an upper wall of said casing includes a passage opening configured to allow passage of the turbine blade into the casing. The system of claim 4, wherein said orifice comprises a seal configured to close a space between the orifice and the turbine blade during maintenance thereof. The system of claim 5, wherein the seal is further configured to provide a damper configured to reduce relative movement of and / or vibrations between the enclosure and the turbine blade. System according to claim 5 or 6, wherein said seal is inflatable. A system according to any of claims 4-7, wherein a lower wall of said enclosure includes a further passage opening configured to allow passage of the turbine blade out of the enclosure. The system of at least one of the preceding claims, wherein said enclosure comprises a plurality of internal platforms that are vertically distributed. System according to at least one of claims 3-9, wherein said enclosure comprises two enclosure halves movable towards and away from each other. System according to at least one of the preceding claims, further comprising a carrier connector configured to connect the carrier to the wind turbine. System according to at least one of the preceding claims, further comprising a casing connector configured to connect the casing to the wind turbine. The system of claims 10 and 12, wherein the sheath connector comprises two clamp halves, each of which extends from a respective sheath half of said sheath. System according to claim 12 or 13, wherein the enclosure is detachable from the carrier and is configured to be temporarily connected to the wind turbine as an autonomous maintenance device. System according to at least one of the preceding claims, further comprising: - one or more motion sensors, configured to monitor a movement of said carrier relative to said wind turbine; and - a control configured to control the driver to actively resist the movement of said carrier relative to said wind turbine. System according to at least one of the preceding claims, wherein the sea-based carrier is a vessel, such as a lifting platform or a push barge. 17. Maintenance device of or for a system according to any of the preceding claims. A method for performing on-site maintenance on a turbine blade of a land or sea-based wind turbine with a maintenance system according to any of the preceding claims, comprising the steps of: - arranging the carrier at the wind turbine; supporting the sheath from the wearer; - fixing the wind turbine to prevent rotation; and - using the actuator to move the casing from said carrier upward along the turbine blade to at least partially encase a portion of the turbine blade of said wind turbine. The method of claim 18, wherein the step of fixing the wind turbine to resist rotation is preceded by the step of positioning the turbine blade to be maintained in a substantially downward orientation.