Measuring Impeller Turbines in Harsh Manufacturing Environments
To operate hydropower plants safely and limit outages, expertise in both measurement and analysis techniques is required. Having precise knowledge of the plant’s conditions and the load on its components is vital. This is particularly true when the impeller turbines function in challenging modern environments.
Challenges: Hydraulic contours of impeller blades are largely responsible for maximizing power generation. Therefore, how can we check if the blade dimensions deviate from the nominal shape?
When individual impeller blades deviate (even slightly) from the nominal contour, the impact on water flows in the entire power plant and, therefore, on energy efficiency is severe. In this context, impeller segments must be measured before assembly to ensure that they meet the required tolerance and manufacturing accuracy. Moreover, the assembled impeller must also be measured to ensure that the accuracy of the assembled components meets the specifications.
Knowing that vibrations and thermal variations prevail in manufacturing environments, how can we guarantee measurement accuracy in these harsh conditions?
Flexible technologies that can adapt to the instabilities of the environment are essential to carry out measurements in industrial steel construction sites. To do so, measurement instruments must be free from a rigid setup that absorbs vibration or variation, impacting the measurement results. In addition, the measuring tool needs to be portable in order to reach parts that are difficult to access otherwise.
Knowing that the diameter of impeller turbines and their individual parts can be five meters or larger, how can we inspect these large parts and guarantee high accuracy?
Choosing a technology that is adapted to large-scale dimensions is crucial to delivering inspection reports with the highest measurement accuracy and repeatability. To do so, photogrammetry remains unmatched. Based on a series of 2D photos, it uses triangulation to generate accurate positioning models for other devices, such as 3D scanners or portable CMM technologies.
Knowing that hydropower plants are under constant pressure over verification obligations, how can they inspect their impeller turbines to the highest industry standards?
In recent years, power plants' requirements for metrology equipment have become more demanding and more exacting as verification obligations and documentation of measurements have become necessary. Advanced technologies are now needed to meet these requirements. Measurements must be meticulously compared with CAD models. Tolerances must be met narrowly. The integrity of massive electromechanical systems depends on a quality inspection.
Photo credit: Andritz
Solution: Portable, Accurate, Fast, and Intuitive 3D Scanning Technologies
Portability means a solution designed for manufacturing environments, i.e., not sensitive to shop floor vibrations, part movement, and environmental instability. Without the requirements of a rigid measurement setup, the entire measuring system can move freely at any time during the measurement sequence.
Accuracy means a technology that can provide the high data accuracy and efficiency of photogrammetry, specifically on large-scale projects and large parts. Because its measurement accuracy is unaffected by the instability of the environment, the metrology solution can accurately measure geometrical entities on parts of any size in harsh environments.
Speed means that little time is needed to perform the measurements and proceed with the data analysis. A quick and detailed scan of the shape of the entire impeller blade can then be made.
Simplicity means sophisticated user guidance technology and laser-projected software feedback that is accessible to everyone, regardless of their knowledge in metrology.
Photogrammetric cameras, such as the MaxSHOT 3D, and 3D scanners, such as the HandySCAN 3D, with PolyWorks Inspector software, are good examples of these portable, accurate, fast, and intuitive 3D scanning solutions.
Photo credit: Andritz
Benefits: With portability, accuracy, speed, and simplicity, defects on impeller blades can be easily identified and corrected.
With 3D scanning, a blade’s dimensional information can be compared and analyzed against target data (CAD). The color mapping function enables the engineers to interpret the measurement results quickly, easily, and clearly.
Using this metrology equipment, the measurement process is accelerated, reducing the time needed for data analysis and model comparison. With an intuitive interface, metrology experts are no longer required to perform measurements and analyze 3D scan data.
Strengthen Process Reliability
With a faster technology, intermediate steps can be added to the measurement process, which contributes to the process’s reliability. Thus, impeller turbines can now be measured before assembly to ensure that they meet the required tolerance and manufacturing accuracy, and after assembly to ensure that the accuracy of the assembled components meets the specified dimensions.
2-year ROI and New Possibilities
The payback period on the new measuring system can be as short as two years, at which point, annual savings will be realized. The equipment can also be used for new applications, such as creating CAD data from old components when no drawing or model is available, reverse engineering applications, and much more.
Photo credit: Andritz
Client: Andritz Hydro GmbH
ANDRITZ Hydro is a global supplier of electromechanical equipment and systems for hydropower stations and one of the leaders in the world market for hydraulic power generation. Headquartered in Vienna, Austria, the company has already installed more than 30,000 turbines globally, which represent over 420,000 MW.
Adding a HandySCAN 3D and a MaxSHOT 3D to their existing metrology equipment portfolio brought new flexibility to their measurement process. ANDRITZ is now able to carry out measurements in different locations, such as its own manufacturing facility, at the supplier's location, or even on customer construction sites. The 3D scanners’ ease of use has helped accelerate and strengthen the entire measurement process.
The company is also very satisfied with the ROI they obtained with Creaform’s measuring systems.
"Creaform technology has taken us to a new level. We can now digitize and measure parts for which our conventional measuring equipment was not designed. This measurement technology is simply innovative as well as easy to use," says Yener Korkmaz, Head of Metrology at Andritz.