Exploring Dilution Potential for Full Load Operation of Medium Duty Hydrogen Engine for the Transport Sector

The current political scenario and the concerns for global warming have pushed very harsh regulations on conventional propulsion systems based on the use of fossil fuels. New technologies are being promoted, but their current technological status needs further research and development for them to become a competitive substitute for the ever-present internal combustion engine. Hydrogen-fueled internal combustion engines have demonstrated the potential of being a fast way to reach full decarbonization of the transport sector, but they still have to face some limitations in terms of the operating range of the engine. For this reason, the present work evaluates the potential of reaching full load operation on a conventional diesel engine, assuming the minimum modifications required to make it work under H2 combustion. This study shows the methodology through which the combustion model was developed and then used to evaluate a multi-cylinder engine representative of the medium to high duty transport sector. The evaluation included different strategies of dilution to control the combustion performance, and the results show that the utilization of EGR brings different benefits to engine operation in terms of efficiency improvement and emissions reduction. Nonetheless, the requisites defined for the needed turbocharging system are harsher than expected and result in a potential non-conventional technical solution.