Advanced H2 ICE Development Aiming for Full Compatibility with Classical Engines While Ensuring Zero-Impact Tailpipe Emissions

Current GHG emissions are rebounding from an intermediate decline during the economic downturn caused by the Covid-19 pandemic. To get back on track to support the realization of the formulated goals of the Paris Agreement, scientific communities suggest that worldwide GHG emissions should be roughly halved by 2030 on a trajectory to reach net zero by around mid-century. Carbon neutrality imposes substantial changes in our energy mix. Hydrogen (H2) is considered to play a key role as a carbon-free and versatile energy carrier for all kinds of applications and use cases.Considering the high technological maturity of internal combustion engines (ICEs), the interest in ICEs powered by hydrogen as a CO2-free solution is rising worldwide.The content of this publication displays the necessary engineering steps to successfully convert a diesel-based engine to H2 DI operation. In this context, upfront simulations work dictated the newly designed combustion system layout and the associated exhaust aftertreatment topology that fulfils the requirements for an appropriate level of charge motion for favorable raw emission levels and thermal efficiencies. To keep development cost low while leveraging the maturity of the base Diesel engine parts, a maximum degree of communality with the given Diesel base engine and its flat cylinder head design was decided. The obtained results demonstrate the significant potentials of the hydrogen engine technology towards future needs.The engine KPI are matching the ones from the diesel base engine while offering a near-zero emission concept thanks to the alignment of engine control and aftertreatment system calibration. Remarkable experimental results regarding emissions at zero impact level, high specific power, dynamic response, and efficiency are presented as well as further potentials and needs for the following research and development work.The technical paper closes with a direct comparison of the key functional data of the origin Diesel engine and the newly engineered H2-powered variant for two target applications in the field of on- and off-highway installations.