Accelleron turbochargers for two-stroke engines

The X300-L series turbochargers are designed to adapt for different requirements that might evolve from an increasing variety of fuels. (Photo: Accelleron)

To come up with its next generation of turbochargers, Accelleron had to rethink the way it did research and development.

Accelleron’s new X300-L series of turbochargers for two-stroke engines came after the company saw a marine industry that was facing a changing landscape from everything to digitalization to fuel choices, said Christoph Rofka, division president for medium and low speed products.

The company knew it couldn’t approach developing a new turbocharger using old methods, Rofka said.

“We changed the process landscape,” he said. “ And we were surprised ourselves about the very positive impact.”

One key was starting with the pre-development of core components, like the compressors and turbine, that normally would be developed within the overall development of the turbocharger.

“We make that process front loaded, we take more risk in the advanced technology development, because there’s no product pressure behind it, we can make bigger steps and take bigger risks and we also have the right to fail,” Rofka said. “If we had done it in the old way of working, the qualification of these core components was very late in the development process, and then you don’t want to fail, because you lose time, and it cost you a fortune. So that already gave us a good starting point for the next generation.”

The X300-L series is currently comprised of the ACCX365-L and ACCX370-L models, both of which offer a platform-based, compact design that the company said is easy to service and to adapt for different requirements that might evolve from an increasing variety of fuels. Because they are designed with margin for the even higher pressure ratios new fuels could require, the series’ core components for specific fuels can be incorporated more rapidly for newbuild projects as well as for upgrading the existing population, Accelleron said.

The company gave a presentation on the development process of the turbochargers at the CIMAC Congress in Busan, Korea.

The new turbocharger design enables the entire rotor subassembly to be exchanged in a single port call using a new or refurbished cartridge. This means instead of servicing every five years, the full run time between overhauls can be used, Accelleron said, resulting in just three scheduled services rather than four across a 25-year vessel lifespan.

“The really exciting story is the flexibility when it comes to maintenance,” Rofka said. “And it’s not only being able to exchange during regular port calls (but) having the digital connectivity.”

The X300-L series is fully enabled with Turbo Insight digital technology, which provides the ability for ship operators to identify performance improvement opportunities and when service will be needed well in advance. The system is also used to help Accelleron to judge exposure-based maintenance needs.

The series’ power density improvements and cartridge concept are designed to allow more flexibility for the turbochargers on engine arrangement. Concept studies have shown the feasibility of turbocharging an engine with a twin arrangement where two X300-L type turbochargers are applied per intercooler instead of one large conventional type without fundamentally changing the engine design concept, Accelleron stated. The result is that the benefits of port call cartridge exchange can be extended to largest engines and vessel types, according to the company, adding that the turbocharger cut-out options increase, leading to added fuel savings.

“The X300-L series re-imagines turbocharging for an era of multiple fuels and increasing cost pressures in shipping,” said Christoph Rofka, president of Accelleron’s Medium and Low Speed Product Division. “A platform-based design means upgrades can be introduced more easily as technology advances and provides the enhanced serviceability that operators need in order to control operating costs. Ship operators need flexible technology to exceed existing performance and excel on their path to decarbonization. The X300-L series delivers exactly that.”

The first X300-L turbochargers are expected to be delivered by the end of 2025, with the first orders being taken in the second half of 2024.