Effect of Injection Duration on Engine Performance and Hydrogen Substitution Limits in Biodiesel-Hydrogen Dual-Fuel Systems

Abstract

As the global community moves toward net-zero emissions, transforming traditional heavy-duty engines into clean energy platforms is essential. This study explores the potential of a single-cylinder diesel engine to transition from fossil fuels to a pure hydrogen future using a biodiesel-hydrogen dual-fuel strategy. Focusing on high-load conditions (4500 W), we systematically evaluated how varying the Duration of Injection (DOI) for both fuels influences performance and energy substitution. Our findings reveal that optimizing injection duration is key to balancing power and efficiency. Peak performance was achieved at a 60° CA DOI with 3.493 kW of brake power, while the highest thermal efficiency of 15.73% occurred at a 70° CA DOI. Notably, the engine successfully substituted up to 26.85% of its energy intake with hydrogen. However, the results also highlight a critical threshold: excessive hydrogen can displace intake air, limiting oxygen for combustion and triggering instability. By synchronizing injection timing and managing thermal loads evidenced by reduced exhaust temperatures at higher efficiencies this research provides a practical roadmap for developing resilient, hydrogen-ready engines that do not sacrifice performance for sustainability.