Characterization of Gaseous and Particle Emissions of a Direct
Injection Hydrogen Engine at Various Operating Conditions 2023-32-0042
This paper investigates the gaseous and particulate emissions of a hydrogen
powered direct injection spark ignition engine. Experiments were performed over
different engine speeds and loads and with varying air- fuel ratio, start of
injection and intake manifold pressure. An IAG FTIR system was used to detect
and measure a variety of gaseous emissions, which include standard emissions
such as NOX and unburned hydrocarbons as well as some non-standard emissions
such as formaldehyde, formic acid, and ammonia. The particle number
concentration and size distribution were measured using a DMS 500 fast particle
analyzer from Cambustion. Particle composition was investigated using ICP
analysis as well as a Sunset OC/EC analyzer to determine the soot content and
the presence of any unburned engine oil. The results show that NOX
emissions range between 0.1 g/kWh for a λ of 2.5 and 10 g/kWh λ of 1.5. The
highest particle concentration was found for low loads and low intake pressures,
with peaks values as high as 5*108 n/cc. ICP analysis confirmed that
the particles contained traces of engine oil, while the OC/EC analysis showed
that 99% of particle matter collected on filters was organic carbon, and <1%
soot. The emissions of N2O as well as several other species measured
with FTIR was found to be in the single ppm range, and thus not significant.