Technical Paper
Effect of Standard Tuning Parameters on Mixture Homogeneity and Combustion Characteristics in a Hydrogen Direct Injection Engine
2023-04-11
2023-01-0284
Dihydrogen, as a zero CO2 fuel, is a strong candidate for internal combustion engine to limit global warming. This study shows the impact of standard tuning parameters on mixture homogeneity and combustion characteristics. A 2.2L Diesel engine on which the head was reworked to allow side mounted direct injector and central mounted spark plug was selected. The discussed tests were made at low engine speed and partial load. A spark advance sweep at different air-fuel ratios (λ) was conducted. The exponential relation between λ and NOx emissions is highly marked and extremely low NOx emissions up to 1.7 g/kWh at minimum spark advance for maximum brake torque can be measured. A λ sweep was performed at different starts of injection (SOI). The results show that, depending on the engine speed, a later SOI might lead to lower NOx emissions. For a λ setpoint of 1.8, at 1500 rpm, late SOI leads to 30% higher NOx emissions where at 2500 rpm these emissions are 26% lower.
