Performance of a Heavy Duty DME Engine – the Influence of Methanol and Water in the Fuel
Paper i proceeding, 2008
In the study reported here the combustion and emission
characteristics of a heavy duty six-cylinder diesel engine
fuelled with dimethyl ether (DME) of chemical grade and
DME with small and varying amounts of methanol and/or
water were experimentally investigated. In addition, the
size distribution of emitted particles and selected
unregulated emissions were sampled.
Methanol and water additions had a very limited effect
on emissions, but affected the combustion processes in
a way that accentuated the premixed combustion and
thus caused more energy to be released early in the
cycle. At high load, however, the effect was reversed,
due to the lack of distinct premixed combustion.
The results confirm that DME combustion does not
generate any accumulation mode particles. The particles
that are detected are smaller than the soot size range
and do not occur in greater numbers than those from a
diesel engine in the corresponding size range.