Wind turbine inspection
Using different technologies and techniques, including video probes and Non-Destructive Testing, we surveyed every part of a wind turbine: from the concrete base on which it stands, to the very tip of its blades and all the mechanics in between.
Challenge
Operating over 35 metres (114 feet) from the ground and with three blades each measuring over 20 metres (65 feet), a wind turbine is not the easiest piece of equipment to inspect.
A wind turbine is situated on a hillside in a fairly harsh environment and is continually exposed to the elements. Ensuring that all the components are operating the way they should is a standard health and safety compliance procedure.
Solution
Using different technologies and techniques, including video probes and Non-Destructive Testing, we surveyed every part of a wind turbine: from the concrete base on which it stands, to the very tip of its blades and all the mechanics in between. Each survey which we undertake is carried out in a way which minimises the risk to the inspector and the time involved in the turbine being out of operation.
Result
The tower is continually exposed to the elements, with gale force winds battering it, the tower can bear the brunt of the weather. Constructed out of welded steel, each section of the tower is bolted together on the inside.
An inspection of the outside of the tower examines the integrity of the welds and details any possible damage. A remote access crawler attaches to the tower with the use of magnets, which allows it to travel vertically and horizontally on the structure to carry out an inspection and feed information back to the inspector on the ground. This eliminates the need for costly scaffolding or rope access.
Internally, visual inspections are carried out to identify any damage to the bolts or flanges. Damage to these can impact on the safety of the turbine. The Nacelle is one of the most important parts, the nacelle houses much of the mechanics of the turbine, including the gearbox, generator, brake, controller and yaw mechanism. If each of these items did not operate correctly then the turbine could fail to generate electricity.
Inspections are carried out with video probes to ensure that there is no damage, and no debris has built up around the moving parts. If the yaw mechanism is damaged then the turbine may not be able to turn its blades against the wind, which could result in greater damage.
As a turbine rotates, heat is generated in the nacelle. If there was debris in the nacelle, this in the worst case could ignite. Video probes allow the inspector to see parts of the mechanism which he can’t by sight. Using retrieval tools debris can be removed.