UNal seeks patent for device that repairs water turbines
A thermal localized heat treatment comprised by software and hardware programs repairs buckets from turbine impellers without the need to remove them from their location.Medellín, 14 de junio de 2016 — Agencia de Noticias UN-
This new invention belongs to the Universidad Nacional de Colombia (UNal) in Medellín Faculty of Mining’ Tribology and Surfaces Research Group, which develops programs along with the Medellín Public Utilities Company (EPM, for its Spanish acronym), some of them related to hydroelectric energy production.
One of the projects consisted on improving the durability and efficiency of turbines to minimize losses and downtime. One of the most frequent damages is loss of form of the paddles or buckets due to the constant water flow, many times with particles or corrosive materials.
The main purpose of the research group was to find a way to rapidly recover the damaged parts and repair them in a suitable manner and also spacing the time between interventions.
The new invention consists of a system that not only quickly repairs turbine buckets but also carries out the process on location without the need to dissemble the turbine, which have diameters between 1 and 5 meters (3 and 16 feet) and can weigh up to 6 tons. Furthermore moving these pieces to the workshop means time, costs and transportation issues.
UNal Faculty of Mining Professor Alejandro Toro says the system is then taken to the hydroelectric water plant where the turbine is located. There they identify the exact location of the damage and produce heat in the desired conditions for an exact amount of time.
“After treatment the turbine is immediately in optimal working condition and ready to be put to service,” he said.
The thermal treatment that the turbines undergo consists of providing heat to parts in a controlled and localized manner. A software program provides information on which pieces of the material are colder or hotter and which need more heat treatment.
“This has enormous implications because when a piece is heated inadequately, it produces unwanted residual tensions which could later result in fractures in the turbine, which can have consequences not only for energy production but for the safety of the workers,” said Toro.
During the course of the project the researchers saw the possibility for their work to have intellectual protection. Although at first they considered the possibility of professional industrial silence, but then they finally opted for processing a patent as it could be marketed to produce profit.
“The real profit, besides the patent is that we learned that things can be made to work, but require effort and this is not an easy task. We need to compromise but at the end with the results, it is very gratifying,” said David Bernardo Hoyos, a student linked to the project
Professor Toro highlights that the participation of the UNal Tribology and Surfaces Research Group played a fundamental role in the process. While some were devoted to aspects such as heat transferal in the turbines, others were analyzing the metallurgy of steel of the turbines. They also researched how the machines are damaged and the corrective measures which need to be taken.
Other inventors of the system were Sebastián Romo, Hernando Pacheco, and Jorge Iván Jiménez.(Por: Fin/SLGS/DMH/APBL