Integrated System for Wind Turbine Tower Inspection

SIUI NDT

1. What is a tower?

The tower is usually designed to be conical or cylindrical, and a large amount of welding work is required during the manufacturing process, including welding of tower section and flanges, tower sections, and foundation rings. The weight accounts for about half of the total weight of the wind turbine. In order to achieve a suitable windward height, it is usually hundreds of meters high.

2. Tower inspection

In addition to supporting the entire cabin and blades, the tower also needs to withstand vibration, corrosion, fatigue, and force changes caused by the environment and working conditions during operation. If there are defects inside the weld, the welding strength will be seriously reduced, and there will be hidden dangers such as fracture and damage, causing major economic losses and safety accidents. In order to ensure the manufacturing quality of the tower, welding inspection is required to ensure its strength and safety. The welds in the tower manufacturing process include the butt welds after the steel plate is rolled into a cylinder, the welds connecting the tower sections, and the welds connecting the tower to the flange. There may be various defects such as non-fusion, incomplete penetration, slag inclusions, porosities, cracks, etc.

The above-mentioned weld defects are usually detected by visual inspection, ultrasonic testing, magnetic particle testing, penetration testing, acoustic emission testing and radiographic testing. At present, the detection of in-service tower welds is mostly carried out by hanging with ropes or building tower ladders. The inspectors are always faced with dangerous high-altitude working environments and long hours of physical labor, which not only poses a threat to the health and safety of the personnel, but also seriously limits the work efficiency and quality.

3. Integrated testing system ALPHA 1006

In response to the various difficulties and problems in wind turbine tower weld inspection, SIUI has developed the integrated testing system ALPHA 1006 (SIUI) , which creatively integrates the ultrasonic module and the wall-climbing scanner. This allows inspectors to work in a safer environment, greatly reducing labor difficulty and pressure and improving work efficiency.

ALPHA 1006 (SIUI) is mainly composed of three parts: a wall-climbing scanner, a wireless remote control, and an rugged laptop with customized software. The scanner is integrated with an ultrasonic module, supports PAUT/TOFD probes. Through manual control or software intelligent planning, the scanner moves on the tower surface to complete the welding quality inspection. In order to adapt to the complex working environment, the system adopts multiple functional designs and safety considerations, and can play the following advantages in the on-site inspection process.

Friendly working environment

• The ultrasonic module and the wall-climbing scanner are integrated. The entire system has only one water pipe for external connection.
• The inspectors basically work on the ground, which greatly reduces the work risks of high-altitude operations.
• It can enter small and dark spaces for inspection, optimize the operating environment of inspectors and reduce work difficulty.

Multiple measures to ensure safety

• Use safety rope to prevent accidental falls.
• Equipped with multiple sensors to obtain real-time information about the surrounding environment, continuously monitor the current environment and scanner status, and avoid possible problems in advance.
• Use industrial-grade magnetic wheels for adsorption, with a load/weight ratio of more than 1.
• The magnetic wheels can automatically adjust its height to achieve adaptive fit to curved surfaces of the tower, and obtain sufficient adsorption force.
• The protection code reaches IP66, which can withstand violent water spray and cope with harsh and complex working environments.

Flexible movement

• The dual-motor module drives the magnetic wheels on both sides to achieve girth, longitudinal and steerable movement on the tower surface.
• Built-in lithium batteries for power supply, no need to carry and connect to bulky power cable. The movement is lighter and more flexible, and it is convenient to transport and carry.
• Avoid hidden dangers such as cable entanglement, damage, and long-distance transmission signal interference during movement.

High-precision movement

• The scanner can move along the weld on the tower surface with high precision according to the planned moving path.
• Encoder integrated with the wheel, adjusts dynamically along the moving path to ensure scanning accuracy.

Remote visual monitoring

• The system is equipped with a wireless camera that can monitor the operation of the scanner in real time. The inspectors can intuitively perceive the surrounding environment and current working status, and adjust the scanner movement at any time as needed.
• The wireless data transmission distance up to 30 meters, meeting the general requirements of on-site inspections.
• The data acquisition is received by the laptop, the parameters can be adjusted as needed in real time.

Expandable

• The system adopts modular design and can be quickly expanded and adapted according to specific workpieces, such as long-distance pipelines and pressure vessels.
• The standard configuration supports 2 PA probes+ 1 channel TOFD probes for simultaneous detection, up to 8 probes.
• It can be expanded with dual-axis raster arm for corrosion mapping.

4. On-site cases

In addition to tower inspection, the integrated testing system ALPHA 1006 can also be used in other application scenarios.