Performance and emissions characteristics of hydrogen-diesel dual-fuel combustion for heavy-duty engines

This study investigates hydrogen-diesel dual-fuelling specifically for a modern 4.4L 4-cylinder heavy-duty diesel engine using extensive one-dimensional combustion modelling in Ricardo WAVE. Parametric analyses from 900 to 2200 rpm speeds and 0 to 17.5% hydrogen fractions introduced via port injection are undertaken to assess the effect of exhaust gas recirculation (EGR) for controlling NOx. Moreover, impacts on key indicators like brake power, torque, thermal efficiency, and emissions are also evaluated. Results revealed that the benefits of hydrogen enrichment are highly dependent on operating conditions. At speeds above 1700 rpm and hydrogen mass fraction of 17.5% remarkable gains were attained, increasing brake power and torque by up to 17% and 16.5% respectively. Brake-specific diesel consumption (BSDC) improves by 29% at higher speeds due to hydrogen's larger energy content. NOx emissions display a trade-off, decreasing substantially by 96% at lower speeds but increasing by 43% at 2200 rpm with 17.5% hydrogen.