ACC, a new era for AM sand casting in Haliade-X offshore wind turbines
GE Renewable Energy and Fraunhofer IGCV to work with voxeljet AG on development to the world's largest sand binder jetting system
GE (NYSE: GE), Fraunhofer IGCV and voxeljet AG (NASDAQ: VJET) have formed a research partnership to develop the Advance Casting Cell, or ACC (which will be the world’s largest system for sand 3D printing) to be used in the production of parts for offshore wind turbines. The machine will produce the world’s largest 3D printed sand molds via voxeljet’s AM sand casting (binder jetting) process, in order to streamline the production of key components of GE’s Haliade-X offshore wind turbines. With the ability to produce molds up to 9.5 meters in diameter and 60-plus tons in weight, it truly marks a new era in additive sand casting.
The ACC 3D printer under development will benefit from financial support from the German Federal Ministry for Economic Affairs and Energy and will be capable of printing molds to cast components for the nacelle of the GE Haliade-X, that can each weigh more than 60 metric tons, reducing the time it takes to produce this pattern and mold from ten weeks or more to just two weeks. In addition, the use of the 3D printer is expected to reduce the product’s carbon footprint by eliminating the need to transport the large parts from a central manufacturing location. The partners expect to launch the project during the third quarter of 2021 with initial printer trials starting during the first quarter of 2022.
GE Renewable Energy has already conducted tests in the use of 3D printing—using the concrete extrusion system developed by COBOD—to build the giant bases of offshore wind turbines such as the Haliade-X on location. There are many other ways that Haliade-X systems, and other offshore wind turbines—could benefit from large format additive manufacturing processes as we discussed in a recent article for our AM Focus 2021 Sustainability and relative eBook.
The ACC project involves the development of a new, large-format 3D printer capable of producing sand molds for AM sand casting the highly complex metal parts of different shapes and sizes that make up an offshore wind turbine nacelle. The modular 3D printing process, which is based on voxeljet’s core “Binder-Jetting” technology, can be configured to print molds for castings up to 9.5 meters in diameter and 60-plus tons in weight, dimensions.
Juan Pablo Cilia, Senior Additive Design Engineer at GE Renewable Energy, said, “The 3D printed molds will bring many benefits including improved AM sand casting quality through the improved surface finish, part accuracy and consistency. Furthermore, sand binder jet molds or additive molds provide cost savings by reducing machining time and other material costs due to optimized design. This unprecedented production technology will be a game-changer for production efficiency allowing localized manufacturing in high-cost countries, a key benefit for our customers looking to maximize the local economic development benefits of offshore wind.”
The Fraunhofer Institute for Casting, Composite and Processing Technology IGCV is responsible for casting and materials technology issues as well as digital process monitoring. “We are taking a close look at thermal management during casting, and we will evaluate the ideal proportions of the printing materials,” said Dr. Daniel Günther, Head of Department Molding Processes and Molding Materials at Fraunhofer IGCV.
“Also, we will develop and test new approaches to process monitoring as part of the project.” Based on prior experience the team expects to significantly improve the environmental footprint of processes involved in producing the Haliade-X type wind turbines. This sustainability aspect is a firmly established guiding principle of research at Fraunhofer-Gesellschaft, according to the institute’s director, Prof. Dr. Wolfram Volk, who adds: “We aim to optimize the mold printing to avoid extremely costly misprints or even miscasts, to save on binder and activator, and to improve mechanical and thermal behavior during casting. By developing a process that conserves resources as much as possible, we want to help to improve the environmental and cost balance in the manufacture of wind turbines.”
Christian Traeger, Director of Marketing and Sales at voxeljet, also commented the ACC project: “The test mold we printed for GE in 2019 consisted of dozens of individual parts. With the ACC, we aim to print a significantly reduced number of parts for the full set. Added to that, the mold can be optimized in terms of functionality and material consumption. This optimization makes completely new casting designs possible that can further enhance the efficiency of the turbines.”
“While offsite on-demand 3D printing provides many benefits for small quantities of cast parts, running a 3D printing system on-site leverages the technology to its fullest capacity. Given the demand for offshore wind turbines, that will help a lot to fulfill project schedules and high market demands,” added Dr. Ingo Ederer, CEO at voxeljet. “With our productive Binder-Jetting technology in combination with our experience in large format industrial 3D printing, we are serving customers in the foundry industry for over 20 years. It is our mission to bring 3D printing into true industrial manufacturing and we are therefore very excited to be part of this groundbreaking project.”
The International Energy Agency3 has projected that global offshore wind capacity will increase 15-fold by 2040, becoming a 1 trillion dollar industry, thanks to falling costs, supportive government policies and technological progress like that behind the Haliade-X offshore turbine from GE Renewable Energy. GE Renewable Energy has been selected to supply its Haliade-X turbine for 5.7 GWs worth of projects in Europe and the US. The company is a member of the Offshore Wind Industry Council (OWIC) and as part of that supports various initiatives that aim at increasing the production of sustainable wind energy.
