Leak detection in wind turbines

Abstract

A wind turbine comprising a tower, a nacelle and a rotor hub. The wind turbine further includes a leak detection system comprising a control unit coupled with at least one elongated fluid sensing member positioned on a component within the wind turbine, the elongated fluid sensing member being responsive to the presence of hydraulic oil from a hydraulic power system of the wind turbine, and / or lubricating oil from an oil supply system of the wind turbine. The control unit is operable to monitor the elongated sensing member and to generate a response action in response to detecting the presence of the hydraulic oil and / or lubricating oil. Usefully, the elongated fluid sensing member enables detection over a greater distance compared with conventional approaches which rely on point detection of fluid leaks. Therefore, the invention provides a more effective system which is better able to detect leaks promptly so appropriate action can be taken to minimise the severity of the leak and to carry out any required clean-up action.

Description

[0001] LEAK DETECTION IN WIND TURBINES

[0002] Technical Field

[0003] The invention relates generally to approaches for detecting fluid leaks within wind turbines, for example leakages of lubricating fluid, hydraulic fluid and coolant.

[0004] Background

[0005] Wind turbines are complex electromechanical systems which comprise various components and systems which make use of, or consume, working fluids. For example, typically a wind turbine incorporates a gearbox housed within the wind turbine nacelle which requires a lubricating oil system for efficient operation and a fluid cooling system to guard against excessively raised operating temperatures. Furthermore, it is usual for wind turbines to include a hydraulically actuated blade pitch system.

[0006] Leaks can occur wherever such lubricating fluids or hydraulic fluids are used. Typically, leak detection approaches rely on the pooling of fluids in certain locations which can then be detected by a suitable sensor, such as a float sensor. More sophisticated approaches are known, which rely generally on monitoring of stored fluid capacities during operation whereby suitable monitoring algorithms can be used to infer the presence of leaks. However, existing approaches tend to only be effective when relatively large volumes of fluid have leaked, which can be problematic. By way of an example, a pitch system is housed predominantly within a rotor hub of a wind turbine which is a relatively confined environment. In this space, a leakage of a few tens of litres will be dramatic as it moves around the interior surfaces of the hub as the hub rotates. Such a leakage, when detected, would require a significant effort to clean up which can increase maintenance burden resulting in undesirable machine down-time.

[0007] By way of further background, CN211230728U proposes a water cooling system for a direct drive wind turbine wherein the cooling system is applied to a generator of the wind turbine. The water cooling system has a leakage monitoring system that relies on pressure readings of the cooling system and leaking readings to infer the presence of a leak.

[0008] A more effective approach to the detection of fluid leaks within a wind turbine is desirable, and it is against this background that the invention has been devised.

[0009] Summary of the Invention According to the examples of the invention, there is provided a wind turbine comprising a tower, a nacelle and a rotor hub. The wind turbine further includes a leak detection system comprising a control unit coupled with at least one elongated fluid sensing member positioned on a component within the wind turbine. The at least one elongated fluid sensing member is responsive to the presence of hydraulic oil from a hydraulic power system of the wind turbine, and / or lubricating oil from an oil supply system of the wind turbine. The control unit is operable to monitor the elongated sensing member and to generate a response action in response to detecting the presence of the hydraulic oil and / or lubricating oil.

[0010] Usefully, the elongated fluid sensing member enables the detection of fluid over a greater distance compared with conventional approaches which rely on point detection of fluid leaks. Therefore, the invention provides a more effective system which is better able to detect leaks promptly so appropriate action can be taken to minimise the severity of the leak and to carry out any required clean-up action.

[0011] In principle, the leak detection system may be applied to any component of the wind turbine. For example, the elongate fluid sensing member may be attached to various surfaces of the nacelle or rotor hub where leakages are possible; for example to interior surfaces of the nacelle and / or applied to the nacelle floor, walls and ceiling surface. However, in particularly advantageous examples of the invention, the component is a fluid-using component from which it could be expected that a leakage could occur. For example, the elongated fluid sensing member could be applied to hydraulic cylinders, accumulators, manifolds and so on. It is particularly useful if the elongated fluid sensing member is flexible so that it is able to be wrapped around components in a suitable route to increase the effectiveness of detection. Moreover, the elongate nature of the fluid sensing member means that it can be selected in different sizes to fit a variety of applications and is insensitive to the size of the component to which it is applied, and its orientation.

[0012] Notably, the control unit is configured not to be responsive to the presence of water on the elongated sensing member. This is beneficial since the present invention is targeting leaks from known systems that use hydraulic oil and lubricating oil. In an environment like a nacelle or hub, in theory there could be humidity in the air which potentially in some situations could condense enough on a detection rope to trigger detection if it was not configured to be non- responsive to water. Further, the control unit may be operable to generate a response action indicative of a sensed fluid leak based solely on the monitoring of the elongated sensing member. No pressure signals or similar may be required, as required in for instance CN211230728U.

[0013] The examples of the invention extend to a wind turbine component having attached thereto an elongated fluid sensing member, the elongated fluid sensing member being adapted to be connected to a computerised control unit configured to detect the presence of fluid using the elongated fluid sensing member.

[0014] In addition to applying to components including an elongated fluid sensing member, the invention also extends to, and embraces, the application of elongated fluid sensing members to those components and, as such, provides a method of adapting a wind turbine component for the detection of fluid leaks, the method comprising: providing a wind turbine component; providing at least one elongated fluid sensing member that is responsive to hydraulic oil from a hydraulic power system of a wind turbine, and / or a lubricating oil from an oil supply system of a wind turbine, and attaching at least one elongated fluid sensing member to the wind turbine component, the elongated fluid sensing member being adapted for connection to a computerised control unit.

[0015] Further optional and advantageous features are referenced in the detailed description and the appended claims.

[0016] Brief Description of the Drawings

[0017] In order that the present invention may be more readily understood, embodiments of the invention will now be described, by way of non-limiting example, with reference to the accompanying drawings, in which:

[0018] Figure 1 is a schematic view of a wind turbine including a leak detection system;

[0019] Figure 2 is a schematic view of the leak detection system in more detail;

[0020] Figure 3 is a view of a rotor hub in the wind turbine of Figure 1 which makes use of the leak detection system in Figure 2, wherein the rotor hub accommodates components of a blade pitch system; Figure 4 is a view from above of a nacelle of the wind turbine in Figure 1 , which shows examples of locations where the leak detection system may be used.

[0021] Detailed Description

[0022] The invention relates generally to approaches for detecting leaks of conductive fluids from components of wind turbines. The approaches that will be the focus of this discussion permit prompt detection of leaks and can provide information about the location of the leaks, both of which are useful factors in the context of leak detection in wind turbines. The examples of the invention therefore do not rely on a significant volume of fluid to leak from a particular fluidusing device for a leak to be detected. Overall, the systems, devices and methods presented herein offer a way of detecting and identifying needed maintenance or repair actions to mitigate potential risks or damage. By monitoring key parameters and offering timely alerts, the system contributes to maintaining the integrity and reliability of the WTG throughout its lifetime. It is particularly beneficial that the leak detection system in accordance with the invention provides for continuous monitoring for the presence of fluids in difficult to reach areas, components and zones within a wind turbine where existing leak detection approaches are impractical.

[0023] With reference to Figure 1 , a wind turbine 2 includes a tower 4 on which a nacelle 6 is mounted. A yaw system may be included to allow the nacelle 6 to yaw with respect to the tower 4 although such a yaw system is not shown in Figure 1 for brevity. The nacelle 6 rotatably supports a rotor 8. The rotor includes a rotor hub 10 to which a set of rotor blades 12 are attached. It will be apparent that the wind turbine 2 of Figure 1 is a horizontal-axis wind turbine, as is generally known in the art. Other types of which turbines are also known, and the invention applies also to these other types of wind turbines.

[0024] As is conventional, the rotor hub 10 is a three-bladed design, although any number of blades is possible, in principle.

[0025] Figure 1 is a schematic view and, as such, provides a general system overview of components associated with the wind turbine 2 that may be relevant to the examples of the invention that will be described here.

[0026] In overview, the rotor hub 10 is attached to a main rotor shaft 14 which rotates together with the rotor hub 10. The main rotor shaft 14 provides a low-speed input to a gearbox 16. The gearbox 16 gears up the rotational speed of the main rotor shaft 14 and provides high speed output shaft which constitutes a generator drive shaft 18. The generator drive shaft 18 drives a generator 20 which converts the mechanical energy of the generator drive shaft 18 to electrical energy, which is generally known in the art. Note that some wind turbine configurations do not include a gearbox and are known as ‘direct drive’ machines.

[0027] A power converter system 22 is coupled to an electrical output 24 of the generator 20. The power converter system 22 converts the AC input power from the generator 20 to a suitable output power format, as required. Typically, the output power of the converter will be three- phase AC at a selectable voltage, phase and frequency. However, the power converter 22 may also output DC power. Power is exported from the wind turbine 2 by a down conductor 25.

[0028] It should be appreciated that the wind turbine components described here have been simplified for the sake of brevity and that, in practice, a wind turbine is a complex piece of machinery which would include many other components and subsystems. However, a full discussion is not crucial for understanding the principle of the invention and so a deeper discussion will not be provided.

[0029] In addition to the main components discussed above which are concerned directly with the conversion of mechanical torque to electrical power, there are other components and system that support operation of the wind turbine 2. Two of these are illustrated in Figure 1 by way of example, namely a hydraulic power system or ‘unit’ 26 and an oil supply system 28.

[0030] The hydraulic power unit 26 has the function of generating a supply of pressurised hydraulic fluid for operating various systems of the wind turbine 2, as would be understood by the skilled person. One such hydraulic system is a pitch system 30 which is generally accommodated within the rotor hub 10 of the wind turbine, and is shown schematically in Figure 1 , and as will be described in more detail later. Although not shown in Figure 1 , hydraulic fluid would be conveyed to the rotor hub 10 typically by way of a pitch tube that extends inside the rotor shaft 14 and coupled to it by a suitable rotating union.

[0031] The oil supply system 28 has the function of supplying lubricating oil and / or coolant oil to the gearbox 16. Although not shown here, the oil supply system 28 may also be configured to supply lubricating oil and / or cooling oil to the generator 20 and may include an oil pump and an oil cooler, although these components are not shown in Figure 1 specifically. The hydraulic power unit 26 and the oil supply system 28 are both generally known in the art and their general operation would be well-understood by a skilled person, so a full discussion will not be provided here.

[0032] It should be appreciated however, that both the hydraulic power unit 26 and the oil supply system 28 can be considered to be fluid-consuming or ‘fluid-using’ components as they make use of a functional fluid to perform useful work within the broader wind turbine system. To this end, therefore, both the hydraulic supply unit 26 and the oil supply system 28 are vulnerable to leakage of fluids used by those systems.

[0033] The wind turbine 2 further comprises a fluid leakage detection system 32 that is adapted to detect leakages from or on components of the wind turbine. The fluid leakage detection system 32 is shown generally in the schematic view in Figure 1 but it is to be appreciated that the location of the fluid leakage detection system 32 as shown within the nacelle 6 should not be considered as applying any positional limitation on the fluid leakage detection system 32 or components and parts thereof. Further discussion of aspects of the fluid leakage detection system will now follow.

[0034] Figure 2 shows the fluid leakage detection system 32 in more detail, which, in overview, comprises a computerised control unit 34 and an elongated fluid sensing member 36.

[0035] The elongated fluid sensing member 36 is adapted to be coupled to the computerised control unit 34 at an interface connector 40.

[0036] The control unit 34 is operable to detect the presence of fluid that is incident at any point along the elongated fluid sensing member 36. The length of the elongated fluid sensing member 36 is selectable for a particular task, and may range from a few centimetres to several metres in length. In some examples, the elongated fluid sensing member 36 may be modular in form and its total length may be achieved by shorter modules that are connected by appropriate electrical connectors to form the full-length sensing member 36.

[0037] Beneficially, the elongated fluid sensing member 36 is flexible in form and so may be adapted to form various shapes and routes when attached to components of the wind turbine 2, thereby providing an increased sensing area compared to point-sensing technologies. The elongated fluid sensing member 36 may be attachable to components and surfaces of the wind turbine by any suitable means, such as by clips or brackets or adhesive tape. The elongated fluid sensing member 36 may be operable to sense the presence of conductive fluids such as organic liquids / hydrocarbons e.g. hydraulic oil and lubrication oil, and also optionally alcohols such as ethylene glycol, to name a few examples for completeness. Other fluid substances may of course be detectable by the elongated fluid sensing member 36.

[0038] As can be seen in the inset panel in Figure 2, the elongated fluid sensing member 36 is in the form of a cable comprising a plurality of cable elements 42. In some examples, the cable elements 42 may be arranged in a twisted form. In some examples, the cable elements 42 may be enveloped within an external braid structure (not shown) for the purposes of containment and strength.

[0039] The cable elements 42 include a pair of base elements 44a, 44b and a pair of conductive elements 46a, 46b. The base elements 44a, 44b have a larger diameter than the pair of conductive elements 46a, 46b and provide the main structural strength of the elongated fluid sensing member 36.

[0040] The base elements 44a, 44b are in the form of a non-conductive polymer which is flexible enough to provide the required bulk flexibility of the elongated fluid sensing member 36. Both base elements 44a, 44b are circular in cross section, in the illustrated example, although that is not essential. In other examples, the base elements 44a, 44b may be merged into a single element to provide a figure-of-eight cross section. Other cross sections are also acceptable.

[0041] The form of the base elements 44a, 44b provides two elongated recesses or pockets 48 where the base elements 44a, 44b meet which is suitable for receiving the narrower-diameter form of the pair of conductive elements 46a, 46, one on either side.

[0042] The conductive elements 46a, 46b may be simple wires. In such an example, the twisted form of the base elements 44a, 44b forms a protective structure to prevent the wires of the conductive elements 46a, 46b from contacting any external conductive surfaces. However, in the illustrated example, the conductive elements 46a, 46b are composed of an inner wire 50 surrounded by a coating 52 which is impervious to selected liquids.

[0043] The inner wires 50 of the conductive elements 46a, 46b are the active sensing elements of the elongated fluid sensing member 36. To this end, the control unit 34 is adapted to apply a voltage to the conductive elements 46a, 46b and sense the voltage drop which varies based on the application of a conductive fluid to the conductive elements 46a, 46b. The base elements 44a, 44b may be solid polymer elements but they may also carry internal conducting wires as is shown here. This may be for the purposes of communication along the elongated fluid sensing element 36 and for sensing breakages along its length.

[0044] The control unit 34 is adapted to sense the presence of fluid along the elongated fluid sensing member 36 and implement an appropriate response action. An appropriate response action depends on what is required in the circumstances. For example, upon sensing the presence of fluid, the control unit 34 may record an appropriate flag in a maintenance log showing that a leakage has been detected and where that leakage is located, or with what component the leak is associated. The control unit 34 may be adapted to implement further algorithms, for example, suitable time delay reflectometry techniques, in order to identify the distance along the elongated fluid sensing member 36 that the leak has occurred.

[0045] Other response actions are also envisaged. For example, depending on the perceived severity of the leak, the detection of the leak may trigger changes in wind turbine operation. For example, the operation of the pitch system 30 may be degraded if a severe leak associated with the pitch system is detected.

[0046] It should be noted that although the control unit 34 is shown in Figure 2 as being attached to one elongated fluid sensing member 36, the control unit 34 may be adapted to couple to more than one elongated fluid sensing member 36. Therefore, the control unit 34 may provide the facility for centralised data collection, analysis and alerting for a wide range of sensing abilities spread about the internal confines of the wind turbine by a network of elongated fluid sensing members 36. It should also be noted that the elongated fluid sensing member 36 may include non-sensing portion for the function of connecting the sensing portion to the control unit 34. In this way, the sensing portion can be located an increased distance from the control unit 34, suitable separated from it by the non-sensing portion.

[0047] The control unit 34 is shown as a standalone module in Figure 2. However, the functionality provided by the control unit 34 may in principle be subsumed into any other computerised control unit of the wind turbine, for example a main wind turbine controller which has the functionality of implementing the main power generation control algorithm of the wind turbine.

[0048] In other examples, the control unit 34 may be equipped with wireless networking functionality to provide an external system (not shown) to receive leakage report logs from the control unit 34. Examples of elongated fluid sensing members are known in the art, and are sometimes known as sensing ‘cables’ or sensing ‘ropes’ which are available commercially, for example as the FG-OD series of products from TTK Liquid Leak Detection Systems, part of the TTK Group of companies. Such examples are known for use in the oil and gas industry for ‘long line’ applications such as pipelines and fuel distribution networks. A further example is also known from US3981181 , which discusses the use of cable-type leak detectors in the context of the transportation of liquid chemicals through pipelines and the transportation of such liquids in storage tanks. In these known cases, sensing cables would tend to be used to erect a cable ‘fence’ around a potential area for spillage so that leaked liquid would pool in the fenced area and trigger a detection mechanism.

[0049] As the skilled person would be aware, such elongated sensing cables / ropes may operate on the principle of capacitive sensing wherein the conductive elements 46a, 46b and the insulating materials (e.g. coating 52) establish a sensing capacitor. When the sensing elements come into contact with a liquid hydrocarbon such as hydraulic oil and / or lubricating oil, the capacitance of the system is altered which can therefore be used to trigger an alert signal. Other sensing principles would also be known to the skilled person. For example, sensing elements in such sensing cables may be surrounded by porous substances such as suitable polymers which are reactive in the presence of conductive liquids to swell. Such swelling alters the resistance of the conductive elements due to the change in composition of the surrounding coating, thereby triggering a leak detection.

[0050] As the skilled person would also appreciate such sensing cables are configurable to sense organic liquids such as hydrocarbon-based hydraulic oils and lubrication oils and to reject the presence of water either as a separate liquid incidence on the sensing cable or where water is intermixed with other liquids. It is against this background that the elongated fluid sensing member 34 finds particular use.

[0051] It is notable that the leakage detection system 32 of the examples of the invention is configured to sense the presence of leaked hydraulic fluids based solely on the electrical input of the at least one fluid sensing member 36 to the control unit 34. Therefore, the leakage detection system 32 does not rely on pressure readings or fluid level quantify readings from hydraulic tanks, fuel tanks or pressurisation systems in order to achieve a reliable leak detection.

[0052] Some specific examples of how the elongated fluid sensing member 34 may be located and used will now be described with respect to Figure 3. Figure 3 shows an exploded perspective view of the rotor hub 10 in Figure 1 , including a pitch system 60. The rotor hub 10 is seen to the left-hand side of Figure 3 and components of the pitch system 60 are shown exploded in relation to one of three blade root apertures 62 of the rotor hub 10.

[0053] The pitch system 60 includes a bearing 63, first and second coupling members 64, 66, and a drive system 68. More specifically, the bearing 63 includes an inner bearing ring 70 mounted to the rotor hub 10 and an outer bearing ring 72 mounted to the blade (not shown in Figure 3). The first coupling member 64 is positioned between the rotor hub 10 and the inner bearing ring 70. The second coupling member 66 is positioned between the blade and outer bearing ring 72. The drive system 68 comprises hydraulic linear actuators 74, which are connected to the first and second coupling members 64, 66 so that the drive system 68 can rotate the inner bearing ring 70 relative to the outer bearing ring 72 and thereby pitch the blade relative to the rotor hub 10.

[0054] The first and second coupling members 64, 66 shown in Figure 3 each comprise a pitch ring for attaching to a respective bearing ring 70, 72. The first coupling member 64 further includes a plate, whilst the second coupling member 66 includes a cross-beam. The plate and crossbeam of the respective coupling members 64, 66 provide mounting points 75 for the hydraulic linear actuators 74.

[0055] The hydraulic linear actuator 74 comprises an actuator body in the form of a hydraulic cylinder 78, in this example, and an actuator rod or ‘cylinder rod’ 80 that is slidable with respect to the cylinder 78 along a rod axis. The cylinder rod 80 has a rod end with a rod end coupling 82 attached to it for connecting to respective connecting mounting points 75 of a respective one of the cross beams.

[0056] As shown in the interior of the rotor hub 10, the pitch system 60 includes a pitch control system 84 that includes one or more hydraulic accumulators 86, a pitch control unit 88 and a hydraulic manifold 90. The one or more hydraulic accumulators 86 and the hydraulic manifold 90 may receive pressurised hydraulic fluid from the hydraulic power unit 26 which is shown in Figure 1 as being accommodated within the nacelle 4, although other locations are possible. Hydraulic fluid may be transferred from the hydraulic power unit 26 to the pitch system 60 internal to the rotor hub 10 by a suitable rotating union (not shown) which permits pipes, cables and other service lines in a stationary reference frame within the nacelle to be transferred to other associated pipes cables and service lines accommodated in the rotating reference frame within the rotor hub 10.

[0057] It should be noted that the pitch system 60 may include other components that are not shown here as Figure 3 is presented in a simplified form, for clarity.

[0058] Still with reference to Figure 3, it should be appreciated that the rotor hub 10 is an important area for leak detection. The hydraulic linear actuators 74 are major consumers of hydraulic fluid and are in almost constant use as the wind turbine control system reacts continually to varying wind conditions and active damping demands. The total volume of hydraulic fluid may be many hundreds of litres, so there is the potential for fluid leaks to cause severe contamination of the interior of the rotor hub 10 but also that hydraulic fluid may leak from the rotor hub 10 to the external environment.

[0059] The inset panel in Figure 3 illustrates one option for a location of an elongated fluid sensing member 36. As is shown, the elongated fluid sensing member 36 is formed into an annular or ring shape and is applied to an end face 92 of the hydraulic linear actuator 74. The elongated fluid sensing member 36 is therefore located very close to the sealing system (not shown) which retains hydraulic fluid within the linear actuator 74 against reciprocating linear movement of the cylinder rod 80. Such a sealing system is prone to leaks and so the configuration of the elongated fluid sensing member 36 so that it wraps around the cylinder rod 80 near to where it enters the hydraulic cylinder 78 which means that leaks can be detected promptly, thereby ensuring that the volume of leaked hydraulic fluid is kept to a minimum.

[0060] Further location options are also shown in Figure 3, as denoted by dashed lines.

[0061] A first option, labelled A, provides for an elongated fluid sensing member 36 that is applied to the one or more hydraulic accumulators 86. The elongated fluid sensing member 36 may be adapted to encircle or wrap around the one or more hydraulic accumulators 86, as is shown here, by virtue of its flexibility but such a configuration is not required. Since the one or more hydraulic accumulators 86 contain pressurised hydraulic fluid, location A is a beneficial location at which to apply an elongated fluid sensing member 36 to ensure that any leaks are detected promptly.

[0062] A second option is shown at location B. Here, the elongated fluid sensing member 36 is adapted to curve around one of the blade root apertures 62, although a similar configuration may be provided at the other ones of the blade root apertures 62. A third option is shown at location C. Here, the elongated fluid sensing member 36 is shown as wrapping around the hydraulic manifold 90 of the pitch system 60.

[0063] Finally, a fourth option is shown at location D. Here, the elongated fluid sensing member 36 is shown as extending about a nose region 94 of the rotor hub 10. Although the viewing perspective of Figure 3 provides an external view of the rotor hub 10, it should be noted that the elongated fluid sensing member 36 would be attached to the interior surface of the rotor hub 10. Such a location may be suitable for detecting miscellaneous leaks from the hydraulic pitch system 60 which may not have been detected by other means. A similar consideration applies for the elongated fluid sensing member 36 applied at location B.

[0064] In the above discussion, the fluid-using components around which the elongated fluid sensing member 36 is arranged are located in the rotor hub 10. However, further location options are provided in the nacelle 6. Figure 4 illustrates some examples of this.

[0065] At location E, the elongated fluid sensing member 36 is shown as being arranged on the gearbox 16. Usefully, the flexible shape of the elongated fluid sensing member 36 permits it to wrap around the gearbox in any configuration which gives it the capability to detect leaks about the gearbox casing at a variety of positions.

[0066] At location F, the elongated fluid sensing member 36 is shown as extending along the nacelle floor 96 which may be useful in terms of general leaks within the nacelle 6.

[0067] At location G, the elongated fluid sensing member 36 is shown as being applied to the hydraulic power unit 26. It should be noted that the location of the hydraulic power unit 26 is exemplary and other locations are acceptable.

[0068] Finally, at location H, the elongated sensing member 36 is applied to a cooling system 98 which may include various components such as a compressor, control valves, pressure regulators and so on. The inset panel in Figure 4 shows in more detail where placement of one or more elongate fluid sensing members 36 may be achieved on an example fluid-using component 100. Here, the one or more fluid sensing members 36 are shown in dashed lines, and are attached to the component 100 and shaped to extend about, along or near to a base 100a of the component, a valve 100b, and the joint between fluid pipes 100c and the component. In each of these example locations, the elongated fluid sensing members 36 is positioned on or close to leakage-sensitive components to ensure that leak detection is achieved with high sensitivity and fast reaction time.

[0069] In Figure 4, there are multiple elongated fluid sensing members 36 located at various locations within the nacelle. Each of the elongated fluid sensing members 36 can be considered to be electrically connected to the control unit 34 (not shown in Figure 4). However, it should be noted that the multiple elongated fluid sensing members 36 may be a single length of cable which are connected together by suitable connectors, possibly spaced from one another by lengths of non-sensing cable, as discussed above. In this way, a single run of elongated fluid sensing member 36 may be used which meanders around various pieces of equipment for fluid detection purposes.

[0070] In the above examples, it will be noted that the elongated fluid sensing member 36 is applied directly to components to detect leakages from them. Therefore, the approach is not dependent on the pooling of leaks fluids to trigger detection and, moreover, does not require the creation of a container to collect leaking substances. Furthermore, since the elongated fluid sensing member 36 are simply applied to existing components, the approach does not require invasive modification of components when retrofitting to incorporate the leak detection system to existing components and systems. A further benefit is that the elongated fluid sensing members used in the leakage detection system are reusable since they can be cleaned after a detection is occurred and monitoring can continue.

[0071] The skilled person would appreciate that the illustrated embodiment is one example of how the invention may be put into effect. Accordingly, the embodiment described herein is provided purely for illustrative purposes and is not to be construed as limiting the scope of the invention. Some variations of the illustrated embodiments have been described above, but the skilled person would understand that other variants are possible without departing from the invention as defined by the claims.

Claims

CLAIMS1. A wind turbine (2) comprising a tower (4), a nacelle (6) and a rotor hub (10), and further including: a leak detection system (32) comprising a control unit (34) coupled with at least one elongated fluid sensing member (36) positioned on a component within the wind turbine, the at least one elongated fluid sensing member (36) being configured to be responsive to the presence of hydraulic oil from a hydraulic power system (26) of the wind turbine, and / or lubricating oil from an oil supply system (28) of the wind turbine; wherein the control unit (34) is operable to monitor the at least one elongated sensing member (36) and is configured to generate a response action in response to detecting the presence of hydraulic oil and / or lubrication oil.

2. The wind turbine of Claim 1 , wherein the component is a fluid-using component.

3. The wind turbine of Claims 1 or 2, wherein the at least one elongated fluid sensing member (36) is positioned on the component such that it wraps around at least a part of the component.

4. The wind turbine of Claims 1 or 2, wherein the at least one elongated fluid sensing member (36) extends along, about, or next to at least part of a leakage-sensitive part of the component.

5. The wind turbine of Claim 4, wherein the leakage-sensitive part includes a valve associated with the component.

6. The wind turbine of Claim 4, wherein the leakage-sensitive part includes a pipe associated with the component.

7. The wind turbine of Claims 1 or 2, wherein the at least one elongated fluid sensing member (36) extends along, about, or next to at least part of a base of the component.

8. The wind turbine of any one of the preceding claims, wherein the component is at least one of a hydraulic accumulator (86), a hydraulic cylinder (74), a hydraulic manifold (90).

9. The wind turbine of Claims 1 to 7, wherein the at least one elongated fluid sensing member (36) is attached to an end face (92) of a hydraulic cylinder (74) and extends about a cylinder rod (80) of the hydraulic cylinder, at least in part.

10. The wind turbine of any one of the preceding claims, wherein the component is located in the rotor hub (10) of the wind turbine (2).11 . The wind turbine of any one of the preceding claims, wherein the control unit (34) is located in the nacelle (6).

12. The wind turbine of Claim 10, when dependent on any of Claims 1 to 3, wherein the at least one elongated fluid sensing member (36) includes an elongated fluid sensing member (36) that is attached to an interior surface of the rotor hub (10).

13. The wind turbine of any one of Claims 1 to 9, wherein the component is located within the nacelle (6).

14. The wind turbine of Claim 13, wherein the component is at least one of: a hydraulic power unit (26), an oil cooler, an oil pump, a gearbox (16), a compressor.

15. The wind turbine of Claim 13, wherein the at least one elongated fluid sending member (36) includes an elongated fluid sensing member that is attached to an interior surface of the nacelle and / or applied to a nacelle floor (96).

16. The wind turbine of any one of the preceding claims, wherein the control unit (34) is configured not to be responsive to the presence of water on the elongated sensing member (36).

17. The wind turbine of any one of the preceding claims, wherein the at least one elongated fluid sensing member is configured to be responsive to the presence of an organic hydraulic oil and / or organic lubricating oil thereon.

18. The wind turbine of any one of the preceding claims, wherein the control unit (34) is operable to generate a response action indicative of a sensed fluid leak based solely on the monitoring of the at least one elongated sensing member (36).

19. A wind turbine component having attached thereto an elongated fluid sensing member (36), the elongated fluid sensing member (36) being adapted to be connected to a computerised control unit (34) configured to detect the presence of hydraulic oil from a hydraulic power system (26) of a wind turbine, and / or lubricating oil from an oil supply system (28) of a wind turbine using the elongated fluid sensing member (36).

20. A method of adapting a wind turbine component for the detection of fluid leaks, the method comprising: providing a wind turbine component; providing at least one elongated fluid sensing member (26) that is responsive to hydraulic oil from a hydraulic power system (26) of a wind turbine, and / or lubricating oil from an oil supply system (28) of a wind turbine, attaching the at least one elongated fluid sensing member (36) to the wind turbine component, the elongated fluid sensing member (36) being adapted for connection to a computerised control unit (34).

Images