As engine load rises from 20% to 44% and MSP increases to about
76%, the misfire bound is reached. With the further increase of MSP
and further decrease of pilot diesel injection, the phase of DMDF
combustion starts to become unstable. Finally misfire occurs in
some cycles shown by Fig. 4. Fig. 4 shows the variation of cylinder
pressure with ten consecutive cycles at misfire condition. It is clear
that roar combustion and misfire occur alternately cycle after cycle.
The misfire combustion in alternative cycles leads to more
unburned charge, characterized by high carbon monoxide and
unburned hydrocarbons, and the increase in coefficient of
variation (COV) of net indicated mean effective pressure (IMEP).
Misfire bound is a further step of partial burn and roar combustion,
as the bounds between misfire and roar combustion or between
misfire and partial burn are not clear. At misfire condition, the small
amount of diesel injected may not be compressed to ignite due to
the large plenty of methanol mixture in combustion chamber and
then misfire cycle occurs. Then in the cycle after misfire the
unburned diesel and methanol from the last misfire cycle together
with the new injected fuel formed high reactivity premixed
mixtures, which is more easily to ignite and more likely to cause
knock. Subsequent cycles show an alternating occurrence of
HCCI-like knock and misfire throughout the relatively short
experiment. The engine speed varies over 300 r/min and combustion
variation is more than 10% COV of net IMEP. Clearly, under
40% of full load, this would impose a maximum MSP of about 65%
in order to remain within tolerable limits under these conditions.
As engine load rises from 20% to 44% and MSP increases to about
76%, the misfire bound is reached. With the further increase of MSP
and further decrease of pilot diesel injection, the phase of DMDF
combustion starts to become unstable. Finally misfire occurs in
some cycles shown by Fig. 4. Fig. 4 shows the variation of cylinder
pressure with ten consecutive cycles at misfire condition. It is clear
that roar combustion and misfire occur alternately cycle after cycle.
The misfire combustion in alternative cycles leads to more
unburned charge, characterized by high carbon monoxide and
unburned hydrocarbons, and the increase in coefficient of
variation (COV) of net indicated mean effective pressure (IMEP).
Misfire bound is a further step of partial burn and roar combustion,
as the bounds between misfire and roar combustion or between
misfire and partial burn are not clear. At misfire condition, the small
amount of diesel injected may not be compressed to ignite due to
the large plenty of methanol mixture in combustion chamber and
then misfire cycle occurs. Then in the cycle after misfire the
unburned diesel and methanol from the last misfire cycle together
with the new injected fuel formed high reactivity premixed
mixtures, which is more easily to ignite and more likely to cause
knock. Subsequent cycles show an alternating occurrence of
HCCI-like knock and misfire throughout the relatively short
experiment. The engine speed varies over 300 r/min and combustion
variation is more than 10% COV of net IMEP. Clearly, under
40% of full load, this would impose a maximum MSP of about 65%
in order to remain within tolerable limits under these conditions.
การแปล กรุณารอสักครู่..

As engine load rises from 20% to 44% and MSP increases to about
76%, the misfire bound is reached. With the further increase of MSP
and further decrease of pilot diesel injection, the phase of DMDF
combustion starts to become unstable. Finally misfire occurs in
some cycles shown by Fig. 4. Fig. 4 shows the variation of cylinder
pressure with ten consecutive cycles at misfire condition. It is clear
that roar combustion and misfire occur alternately cycle after cycle.
The misfire combustion in alternative cycles leads to more
unburned charge, characterized by high carbon monoxide and
unburned hydrocarbons, and the increase in coefficient of
variation (COV) of net indicated mean effective pressure (IMEP).
Misfire bound is a further step of partial burn and roar combustion,
as the bounds between misfire and roar combustion or between
misfire and partial burn are not clear. At misfire condition, the small
amount of diesel injected may not be compressed to ignite due to
the large plenty of methanol mixture in combustion chamber and
then misfire cycle occurs. Then in the cycle after misfire the
unburned diesel and methanol from the last misfire cycle together
with the new injected fuel formed high reactivity premixed
mixtures, which is more easily to ignite and more likely to cause
knock. Subsequent cycles show an alternating occurrence of
HCCI-like knock and misfire throughout the relatively short
experiment. The engine speed varies over 300 r/min and combustion
variation is more than 10% COV of net IMEP. Clearly, under
40% of full load, this would impose a maximum MSP of about 65%
in order to remain within tolerable limits under these conditions.
การแปล กรุณารอสักครู่..
