Geothermal energy continues to circulate thanks to a 3D printer »3dpbm
As part of our ongoing AM Focus 2021 sustainability goal, we looked at how 3D printers can help make energy production cleaner and more efficient. One way is to help the development of next-generation nuclear power plants, another is to make fossil fuel-based energy production cleaner and more efficient. Yet another is to help develop more efficient renewable energy production systems. One segment where AM applications are still hard to find is geothermal energy. Now, Enel, Italy’s largest energy company (the Italian state is the largest shareholder with 23%), through its Enel Green Powder division, has shown how 3D printers can help geothermal power plants to operate more easily and efficiently by providing spare parts at a significantly reduced cost. fresh.
The success story recently involved the Metallurgy Laboratories of Santa Barbara d’Enel in Cavriglia, near Arezzo, as part of our Geyser d’Enel project. This project is dedicated to geothermal energy, one of the most widely used renewable sources; Italy – and Enel Green Power – are leaders in this area.
Geyser’s objective is to optimize the management of geothermal power plants, ensuring their durability and full functionality, increasing their operational efficiency and constantly improving their technical and financial performance – while paying particular attention to safety and the environment.
The team working on the project organized a round table of technicians and experts from the geothermal, thermal and hydroelectric sectors. This is where the idea of using a 3D printer for the first time to repair an essential component of a geothermal power plant arose.
“It all started with our curiosity and our desire to use the 3D printer that we had in-house,” said Nicoletta Mazzuca, Enel Green Power’s project manager for Geyser, which is developing around 42 initiatives involving more than 80 people. “We wanted to repair parts that were going to end up in landfills because they could not be repaired with conventional forging techniques. But, thanks to the passion, skill and cooperation of our colleagues, we found a solution.
The 3D printer is provided by Prima Additive, and Enel actively participated in its development (as reported by our Italian sister site Replicatore). The LMD machine (Prima Additive also offers LPBF metal technology) is located in the metallurgical laboratories of Santa Barbara, at the engineering and technical support headquarters for Enel Production, and has been available since 2019. This extremely high-tech tool can reproduce and repair various metal parts by depositing the necessary material one layer at a time.
“The fact that the printer is located in an area that also has a metallurgy laboratory provides immense added value. In this way, the additive manufacturing process can be monitored almost in real time, checking the mechanical, chemical and metallurgical properties of the manufactured items so that we can also count on constant feedback ”, explained Giulio Andrucci, technical manager and coordinator of the Santa Barbara Metallurgy Laboratory.
The printer was used to repair an impeller, which is a critical component of a geothermal power plant’s centrifugal compressor because it extracts non-condensable gases from the steam at the end of the expansion process in the turbine. Non-condensable gases contain solid particles and water droplets which impact the blades, wearing away the exterior of the intake profile.
The pilot project began with the purchase of a powdered form of the material used to make the impellers (17-4 PH stainless steel), followed by laser scans and the creation of the 3D model. The work was carried out by a team led by Gennaro Raniello, responsible for hydraulic maintenance assistance – O&M Hydro Italy at Enel Green Power, and ended with the first historic repair of a worn part using this technology. The result is a lasting innovation that will start a cycle of material reuse: until now, worn wheels were simply replaced with new ones and ended up in landfills, so repairing them will also save around 70,000. € per year.
The economic calculation takes into account the restoration of four out of six wheels, on average, which break every year in our geothermal power plants. This estimate takes into account that the damage may be too great in some cases, so two out of six might not be repairable at all. “After a year of work, we were able to use additive manufacturing processes to repair our impellers for the first time. Not only does this give our wheels a second life, but it also saves us money while respecting the environment thanks to 100% circularity. I am honored to have participated in the creation of this innovative repair process and I want to thank my colleagues for teaching me so much in such a short time, ”added Nicoletta Mazzuca.
“The Geyser project allowed us to present and share the skills available in several poles of excellence of the different supply chains of Enel in Italy”, explained Matteo Niccolai, responsible for maintenance of workshops and technical services – O&M Geo Italy by Enel Green Power. “The idea of using additive manufacturing to solve one of Geo’s supply chain problems is a concrete example of how effectively problems and best practices are shared across the company,” by solving critical problems using new perspectives.
This is an achievement that further strengthens the centuries-old history of geothermal energy in Italy, where EGP operates the oldest and most innovative power plant complex in the world, with 34 factories located in the Tuscan provinces of Pisa, Siena and Grosseto.