Additive manufacturing: Better turbines thanks to 3D-printing

The burners look good. A little wear at the edges, but nothing the engineers at E.ON Energy Projects and Siemens Energy didn’t expect. For nearly one year, more than 8,000 operating hours, the burners had been firing a gas turbine in an ultra-modern combined cycle power plant in Philippsthal in the German state of Hesse.

Although expected, the results are still remarkable:  They were printed layer by layer using Selective Laser Melting (SLM) technology. "As an energy service provider, precision and durability of our turbines are absolute necessities for us," says Niklas Lange, project manager at E.ON Energy Projects. "In our experience, additive manufacturing delivers this and even improves performance compared to older models.”

Additive manufacturing is revolutionizing the development and production of components – not just in the automotive and aerospace industries but also in the energy sector. For example, it’s becoming increasingly difficult for conventional manufacturing technologies to produce more efficient or low-emission turbines with higher temperature tolerances. 3D-printing now makes it possible to produce almost any structure imaginable from polymers, metals, or ceramic materials. It accelerates rapid prototyping, which in turn shortens the design and market introduction of new components and devices. It is also more sustainable, because it uses up to two-thirds less material.

The benefits are reflected in the burners. In 2017, they were manufactured at a Siemens Energy plant in Finspång, Sweden, as part of a pilot project for additive production in the energy industry. Each burner is manufactured in one piece, whereas they used to require 13 individual parts and 18 welds. This reduces error tolerance during production and also means that the parts are more similar, so production problems are less likely. The design has also been improved. The pilot-gas feed isn’t mounted outside as a separate pipe: It’s now a part of the printed burner. All of the new design measures allow the operating temperature to be kept lower. In turn, the burner shows a lower dynamic load at the same output, and the turbine as a whole is subjected to less stress – all of which extends the component’s lifespan.

When Lange saw the burners ­­­­­at a meeting with Siemens Energy in Finspång, he was impressed. "One advantage was specifically important to me: Since these burners can be printed with low error tolerances, one can exchange them without having to tune the whole combustion mechanism anew – a 'plug & play' process that hasn’t been available for burners so far." Since Lange was in charge of a turbine at the plant in Philippsthal which these burners fit exactly he was willing to give them a try. "We carried out a careful risk analysis, the results were positive," says Lange. Even if there were anomalies they would be immediately noticed. For example, temperature sensors on the burners constantly provide feedback on their current status. "So, I was confident that these burners would be a good solution for us”, says Lange.

After E.ON Energy Projects and Siemens Energy had reached an agreement, engineers from both companies installed 18 burners in the turbine in Philippsthal in July 2017. After 2,000 operating hours, they performed a first minor inspection of the turbine. In the summer of 2018, after more than a year of operation, the major inspection took place - with positive results.  It marked a milestone on the way to the industrialization of 3D-printing for the energy industry.

The cooperation between E.ON and Siemens Energy benefited both companies. E.ON was able to offer its customers improved services. "E.ON Energy Projects provides tailor made energy solutions for clients in the chemical, paper & pulp and other high energy consuming industries,” explains Lange. “For that we rely on the top-quality standards of the major components delivered from our suppliers such as Siemens on site.”  E.ON Energy Projects also collects and analyzes data from these burners, which can use to further optimize their design.
 

"Thanks to 3D-printing we’ll be able to develop even more powerful, environmentally friendly, and durable gas turbines and components in the future,” says Vladimir Navrotsky, Technology Director in Finspång, who has been advancing additive manufacturing at Siemens Energy for years. "Cooperation with customers such as E.ON Energy Projects enables us to test new technologies and, where necessary, improve them - faster than would otherwise be possible.”

The most important prerequisite for a successful cooperation like this one is mutual trust. "This project went far beyond the traditional relationship between manufacturer and customer," says Lange. "Without such strategic partnerships, innovations in the energy sector would certainly take much longer. They are the key to success when it comes to remaining competitive and offering our customers the best possible performance.”

October 2, 2018

Hubertus Breuer is a science and technology journalist based in Munich.

Picture credits: E.ON / Siemens Energy