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Background
The experiments were conducted on a 6-cylinder, 6 L, naturally aspirated, water-
cooled, equipped with DPF, direct-injection HDDE of model year 1992 (Hino W06E).
The HDDE was tested under two loads, 25% and 75%, under steady cycle on a
dynamometer.
The test fuels included neat diesel (reference fuel), hydrogen-, methane- and natural-
gas mixed with diesel.
Aerosol sampling, dilution and thermal conditioning include:
a rotating disc thermo-dilutor (Matter Engineering Model MD19-2E)
a thermal conditioner (ThC, Matter Engineering Model ThC-1).
• The diluted exhaust samples were then measured at ~25 and 300ºC, with which
the former is referred to as "volatile" and the latter as "nonvolatile" particles.
a scanning mobility particle sizer and condensation particle counter (SMPS/CPC)
system (GRIMM Model 5.500).
Experimental
Results and Discussion
Emissions of volatile and nonvolatile nanoparticles from HDDE running on different gas-diesel mixture fuelsL.-H. Young1*, Chau-Wei Lai1, Hsi-Hsien Yang2, Lin-Chi Wang3, Jau-Huai Lu4, Wen-Jhy Lee5
1Department of Occupational Safety and Health, China Medical University, Taichung 40402, Taiwan. 2Department of Environmental Engineering and Management, Chaoyang University of Technology, Taichung 41349, Taiwan. 3Department of Civil Engineering and Geomatics,
Cheng Shiu University, Kaohsiung 83347, Taiwan. 4Department of Mechanical Engineering, National Chung Hsing University, Taichung 40254, Taiwan. 5Department of
Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan
*Corresponding author: lhy@mail.cmu.edu.tw
(2018) 22nd ETH Conference on Combustion Generated Nanoparticles
China Medical University, Taichung, Taiwan
Acknowledgements
June 18-21, 2018 @ ETH-Zurich, Switzerland
Conclusions
Engine emission
valve
MD19-2E control unitElectronic
signal
Diluted
Sample
Rotating disk diluter
Thermo denuder and
Control unit
DM
A
Auxiliary pump
CPC
Dynamometer
Hino W06E (6000 c.c.)
Gas feul tank
Air intake filter
PUMP
75%-Load25%-Load
Pure Diesel M100 H100
Em
issio
n fa
cto
r, E
F (
#/b
hp
-hr)
1010
1011
1012
1013
1014
1015
1016
(b) EF25C 75%-Load
97.2%93.0%
19.3%
w/o DPF
w/ DPF
Pure Diesel M100 H100
Em
issio
n f
acto
r, E
F (
#/b
hp
-hr)
1010
1011
1012
1013
1014
1015
1016
(b) EF300C 75%-Load
98.3%98.2%
99.7%
w/o DPF
w/ DPF
Particle Diameter, Dp (nm)
10 100
Num
be
r C
on
centr
atio
n
dN
/dlo
gD
p (
#/c
m3)
0
107
2x107
3x107
4x107
0
107
2x107
3x107
4x107
5x107
w/o DPF
w/ DPF (right axis)
H100 NT25C (75%-Load)
1x
68.4 nm
22.6 nm
1x
Particle Diameter, Dp (nm)
10 100
Num
ber
Concentr
ation
dN
/dlo
gD
p (
#/c
m3)
0
2x106
4x106
6x106
8x106
0
3x105
6x105
9x105
1x106
2x106
w/o DPF
w/ DPF (right axis)
Pure Diese NT25C (75%-Load)
62.2 nm
62.2 nm
The use of gas-diesel mixture fuels resulted in increases of both volatile and non-
volatile particles number emissions, compared to that from pure diesel fuel. In general,
hydrogen and biogases resulted in the highest EF.
The increase of engine load (mostly in rpm) resulted in decreases of both EF25C and
EF300C, but slight increases of particle mode diameters.
The particle number remained relatively stable before and after heating to 300ºC,
indicating little volatile materials on the nanoparticles, except H2.
Diesel engine exhaust contains hazardous gas pollutants and nanoparticles (<100 nm)
that have been linked to adverse health effects and environmental impact. Amongst,
diesel engine particles (DEPs) are a complex mixture of nonvolatile (or solid) and
semivolatile components. The emission characteristics of the DEP depend on engine
type, speed, load, fuel type, aftertreatment and sampling conditions.
Recently, the need and trend of energy conservation and pollution abatement have
given rise to the use of gas fuels (e.g., hydrogen, methane, natural gas) gas-diesel
mixture fuels in diesel engines. The pollutant characteristics of such dual-fuel system are
not well studied, especially for number-based nanoparticles.
With that in mind, this study aims to evaluate the effects of gas-diesel mixture fuels
and diesel particulate filter (DPF) on the emission characteristics (number/size
distribution) of volatile and nonvolatile nanoparticles in heavy-duty diesel engine
(HDDE) exhaust.
Items Contents Notations
Commercial diesel Neat diesel Pure Diesel
Hydrogen H2:100% H100
Methane CH4:100% M100
Biogas A CH4:90% + CO2:10%* M90C10
Biogas B CH4:70% + CO2:30%* M70C30
Results and Discussion
Fig. 1 Gas fuel system
Fig. 2 Sampling/analytical
system
Fig. 3 Emission factors of volatile (EF25C) and nonvolatile (EF300C) particle number
for HDDE running on different gas-diesel mixture fuels under 25% and 75% load.
The use of gas-diesel mixture fuels resulted in increases of both volatile and non-volatile
particles number emissions, compared to that from pure diesel fuel, but have negligible
effects on the size distribution. Such observations may be related to the replacement of
O2 by the fuel gas, decrease of A/F ratio, and hence more incomplete combustion or
unburned fuel, indicated by the increase of HC emissions.
The DPF is highly effective for the removal of nonvolatile nanoparticles, regardless of the
engine load and gas-diesel fuel type, but not necessarily for volatile nanoparticles.
The increase of HC emissions from the use of gas fuels (H2 and CH4) may also increase
the likeliness of new “volatile” particle formation downstream of the PDF.
The increase of engine load (mostly in rpm) resulted in decreases of both volatile and
non-volatile particles number emissions, but slight increases of particle mode diameters.
This may be attributable to the high particle number and thus stronger coagulation growth
under high load.
The nanoparticles emitted under the tested conditions contained little volatile materials
on the nanoparticles, except H2.
The above results highlight that the benefits of gas-diesel mixture fuels for aerosol mass
reductions are possibly accompanied by the increase of aerosol number emissions.
Fig. 4 Size distributions of volatile (N25C) and nonvolatile (N300C) particle number for
HDDE running on different gas-diesel mixture fuels under 25% and 75% load.
Fig. 5 Emission factors of volatile (EF25C) and nonvolatile (EF300C) particle number
with and without DPF under 25% and 75% load.
EF25C @ 75% Load EF300C @ 75% Load
Fig. 6 Size distributions of volatile (N25C) particle number
with and without DPF under 75% load.
This work was supported by Taiwan’s Ministry of Science and Technology under the contract number of
MOST 106-2111-M-039-001. Also, thanks to the conference sponsors for waiving the participation fees.
new “volatile” particle formation
new “volatile” particle formation
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