Introducing the Fuel Flexible Injection system (FFI)
Through the long-running HERCULES series of collaborative projects, technologies holding the promise of reducing the environmental impact of shipping were developed between engine designers, universities and technology companies across Europe to advance the performance of large marine engines. The FFI development was an important contribution to the last project in this series, in which WinGD has led the design of an injection system that would facilitate the assessment of a future fuel mix that is not only comprised of both liquid and gas fuels, but also involves a considerably larger range of liquid fuel types.
“A fuel injection system which can inject everything from residual fuels to methanol would likely be able to cover most of the possible liquid fuel alternatives in the future.”
Dr. Andreas Schmid
General Manager, Technology Development
WinGD
Increasing the spectrum of flow flexibility for improved capability
The wide range of properties of liquid fuels mean that different injection strategies are needed to ensure complete and efficient combustion of all these fuels. Alcohols, for example, have half the energy density of traditional marine fuels. To allow for fuels with different energy densities, the FFI system has a variable flow area.
When traditional liquid fuels like HFO or marine diesel oil are to be used, the needle opens only the lower row of orifices. Opening both rows of spray orifices increases the injection rate and allows the use of fuels with low energy density.
Cleaner fuels. Lower emissions.
As further investigation of low-carbon liquid fuels continues, we are well placed to identify the most likely fuels to help reduce the emissions of the shipping industry. The promising development of the FFI system has already highlighted the potential benefits of ethanol fuel, including lower NOx formation and smoke emissions.
Commercial injection concepts continue to evolve and FFI is an important basis to build upon. As the types of fuels that will be available in the future will become more well-defined, further improvements to the system are expected. Our experimental injection set-up has been calibrated for research, and as we shift towards performance testing with more tailored injection concepts, even greater results could be achieved that allow for the reduction of the amount of diesel fuel needed.
“[As] the injection system is the most challenging element of designing an engine for low-carbon fuels, this experimental design will give us an important head start.”
Dr. Andreas Schmid
General Manager, Technology Development
WinGD