Future technological directions for hydrogen internal combustion engines in transport applications
Year: 2024
Type: article
Abstract: The paper discusses some of the requirements for manufacturers to develop hydrogen combustion engines for use in two types of market application – on-road heavy- and light-duty. One of the main requirements is legislative certainty, and this has been afforded – at least in the major market of Europe – by the European Union’s recent adoption of tailpipe emissions limits specifically designed to encourage the uptake of hydrogen engines in heavy-duty vehicles, giving manufacturers the confidence they need.It then discusses combustion and boosting systems for the two market types, emphasizing that heavy-duty vehicles need best efficiency throughout their operating map while light-duty ones, since they are rarely operated at full load, will primarily need efficiency in the part-load region. This difference will likely cause a divergence in solutions, with heavy-duty engines running very lean everywhere and light-duty ones likely operating at the chemically-correct air-fuel ratio. The impacts of the strategies on engine systems and vehicle integration are discussed.It is postulated that hydrogen engines will rapidly adopt direct injection and that heavy-duty types will migrate towards typical current spark-ignition-type cylinder head architecture. They may adopt active pre-chamber technology to ignite extremely lean mixtures for maximum efficiency. Meanwhile, light-duty engines will likely evolve less from their current gasoline architectural norm but, since part-load efficiency will be important, some new operating strategies may become desirable. Developing dual-fuel light-duty engines could accelerate uptake.The likely technological evolution suggests that variable valve trains would be extremely useful for all types of hydrogen engine, especially since they are readily available in gasoline engines now. New operating strategies afforded by variable valve trains would benefit both heavy- and light-duty engines. There will therefore likely be a convergence of technologies for the two markets, albeit with some key differences due to their vehicle applications.
Author: J.W.G. Turner
Institution: King Abdullah University of Science and Technology
Language: English
Subfield: Fluid Flow and Transfer Processes
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,000
OpenAlex ID: W4404056034