Advanced combustion strategies for enhanced performance and emissions control in light-duty hydrogen internal combustion engines

[EN] This study experimentally investigates combustion and emission control strategies for a spark-ignition direct-injection hydrogen (DI-H2) engine operating under high-load and high-speed conditions. The work systematically evaluates the influence of air dilution, exhaust gas recirculation (EGR),...

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Detalles Bibliográficos
Autores: Molina, Santiago|||0000-0001-7879-2421, Gómez-Soriano, Josep|||0000-0002-2742-9224, Echavarria-Olaya, Juan David|||0000-0002-9611-0751, Olcina-Girona, M., Gessaroli, D., Pesce, F. C.
Tipo de recurso: artículo
Fecha de publicación:2026
País:España
Institución:Universitat Politècnica de València (UPV)
Repositorio:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Idioma:inglés
OAI Identifier:oai:dnet:riunet______::6ef34493dea1e730a25877a7a16a1ca8
Acceso en línea:https://riunet.upv.es/handle/10251/233582
Access Level:acceso abierto
Palabra clave:Hydrogen
Direct injection
Water injection
Lean combustion
Spark-ignition engine
Descripción
Sumario:[EN] This study experimentally investigates combustion and emission control strategies for a spark-ignition direct-injection hydrogen (DI-H2) engine operating under high-load and high-speed conditions. The work systematically evaluates the influence of air dilution, exhaust gas recirculation (EGR), multi-pulse injection, and water injection on combustion phasing, knock tendency, and cycle-to-cycle variability. Results show that air dilution effectively reduces NOx emissions-particularly at high excess air ratios (lambda >= 2.2), while maintaining stable combustion and high efficiency. Advancing combustion phasing toward TDC improves indicated efficiency levels but increases knocking risk at lower dilution levels (lambda = 2.0). EGR dilution, at a fixed lambda = 2.3, further decreases NOx but leads to unstable operation and reduced gross indicated efficiency (GIE). Multi-pulse injection strategies, in which approximately 20% of the total injected fuel mass is shifted from the main pulse to an early pilot injection during the intake stroke, provide no efficiency gain and increase stability and NOx compared with single-pulse operation. In contrast, moderate water injection (water-to-hydrogen mass ratio of approximately 2) achieves over 50% NOx reduction with acceptable combustion stability, while excessive injection (water-to-hydrogen mass ratio of 3) degrades efficiency and stability. Overall, the results highlight air dilution as the most effective strategy for balancing efficiency, emissions, and stability, while water injection offers promising potential for additional NOx control and knock mitigation. These findings provide quantitative insights into optimizing combustion strategies for high-load DI-H2 engines and support the development of efficient, low-emission hydrogen combustion systems.