187
Dimethyl Ether
Relative soot emission
1.0
0.8
0.6
0.4
0.2
0.0
Beatrice et al., 1997
Cheng and Dibble, 1999
Miyamoto et al., 1998
Scholl and Sorenson, 1993
DTU
DMM-DTU
DME
0
1 0
2 0
3 0
4 0
5 0
Percent oxygen
Figure 6.10
The smoke formation tendencies of various fuels in diesel engine as a function of fuel oxygen
content.
Miyamoto et al. 1998) and unpublished studies of the author. There does not
appear to be a specific fuel effect on the reduction of smoke formation for
these fuels. The lack of soot formation in a diesel flame has been shown on
a detailed level to depend on the atomic C/O ratio of the fuel air mixture
(Curran et al. 2001).
The first version of a DME commercial 7 liter diesel engine satisfied emissions standards of up to a decade in advance of existing technology, using
EGR and only a passive oxidation catalyst to clean up CO emissions (Fleisch
et al. 1995). Thus a DME diesel engine offers significant advantages in that
an exhaust gas after treatment system for particulate matter is not necessary. For conventional diesel engines, particulate matter control normally
requires a form of filtration, and requires a complicated filter regeneration
system, possibly combined with a fuel additive to assist filter regeneration.
Figures 6.11 through 6.13 show the basic situation concerning operation
with DME in diesel engines. These data are from the very first engine tests
with DME conducted by the author on a small diesel engine, and the trends
shown here have been seen in all subsequent engine tests with DME in a
wide range of diesel engine types and sizes. In the tests shown, the engine
was operated with the standard fuel injection pump and injection nozzle,
but with a lower injector opening pressure than the diesel version, 80 bar
instead of 200. Since the pump volume was the same for DME and diesel, a
larger volume of DME had to be injected due to its lower heating value, and
this occurred over a longer period of time. This, and the low injector opening
pressure, would be expected to give very high smoke emissions in an engine
operating with diesel fuel.
Dimethyl Ether
Relative soot emission
1.0
0.8
0.6
0.4
0.2
0.0
Beatrice et al., 1997
Cheng and Dibble, 1999
Miyamoto et al., 1998
Scholl and Sorenson, 1993
DTU
DMM-DTU
DME
0
1 0
2 0
3 0
4 0
5 0
Percent oxygen
Figure 6.10
The smoke formation tendencies of various fuels in diesel engine as a function of fuel oxygen
content.
Miyamoto et al. 1998) and unpublished studies of the author. There does not
appear to be a specific fuel effect on the reduction of smoke formation for
these fuels. The lack of soot formation in a diesel flame has been shown on
a detailed level to depend on the atomic C/O ratio of the fuel air mixture
(Curran et al. 2001).
The first version of a DME commercial 7 liter diesel engine satisfied emissions standards of up to a decade in advance of existing technology, using
EGR and only a passive oxidation catalyst to clean up CO emissions (Fleisch
et al. 1995). Thus a DME diesel engine offers significant advantages in that
an exhaust gas after treatment system for particulate matter is not necessary. For conventional diesel engines, particulate matter control normally
requires a form of filtration, and requires a complicated filter regeneration
system, possibly combined with a fuel additive to assist filter regeneration.
Figures 6.11 through 6.13 show the basic situation concerning operation
with DME in diesel engines. These data are from the very first engine tests
with DME conducted by the author on a small diesel engine, and the trends
shown here have been seen in all subsequent engine tests with DME in a
wide range of diesel engine types and sizes. In the tests shown, the engine
was operated with the standard fuel injection pump and injection nozzle,
but with a lower injector opening pressure than the diesel version, 80 bar
instead of 200. Since the pump volume was the same for DME and diesel, a
larger volume of DME had to be injected due to its lower heating value, and
this occurred over a longer period of time. This, and the low injector opening
pressure, would be expected to give very high smoke emissions in an engine
operating with diesel fuel.