View
216
Download
0
Category
Preview:
Citation preview
Testing of various fuel and additive
options in a compression-ignited
heavy-duty alcohol engine
2015 Polttomoottori- ja turboteknologian seminaari
Espoo, 7.5.2015
Timo Murtonen, Nils-Olof Nylund,
Mårten Westerholm & Christer Söderström (VTT)
Timo Huhtisaari (NEOT)
Gurpreet Singh (DTU)
2 2
Bioruukki Pilot Centre National asset, international atmosphere, global competence
Scale-up and demonstrations for companies Flexible research and piloting infrastructure
Small scale manufacturing for SMEs
Combined with strong competence pool and expertise
International innovation ecosystem for research partners Large networks in Europe and globally
VTT Brazil a window to South American markets
Team Finland partner
In Espoo, close to Otaniemi innovation hub 500 experts in bioeconomy
Close connections to universities
Active stakeholder in national bioeconomy Supports national targets
Connects national players in bioeconomy – FIBIC, INKA etc.
MAKES BIOECONOMY REAL
3 3
Bioruukki Pilot Centre – Enabler of national bioeconomy and cleantech strategies, platform for circular economy based activities
1. Renewable Energy Sources
Infrastructure - RES Infra
Thermochemical conversion
platform; gasification and pyrolysis
technologies
2. Biomass Centre - BIO-infra 1
Biomass fractionation and processing
for new biobased value chains
3. Green Chemistry Centre - BIO-infra 2
Sustainable process chemistry; high-
consistency processing
4. Solar Centre - BIO-infra 3
Storage and distribution systems to
solar energy
Unique combination
of FOUR technology
platforms
4 4
Background of the project
The International Energy Agency Implementing Agreement on Advanced
Motor Fuels has initiated an activity, Annex 46, on alcohols fuels for diesel
engines
The goal is to report the best possibilities for implementation of alcohols in
diesel engines
Two research partners, DTU Technical University of Denmark and VTT of
Finland teamed up in this activity, with technical support from Scania
DTU and VTT have their respective research agendas:
DTU is carrying out work with an experimental engine
VTT has conducted work using a commercial Scania heavy-duty
ethanol engine
5 5
Motivation
Especially in Europe, there is a shortage of middle distillates
The commercial vehicles are in practise running on diesel fuel only,
and diesel fuelled passenger cars have become increasingly popular
The demand of aviation kerosene is increasing, as well as the demand
of distillate fuels in the marine sector, due to the new limits on sulphur
dioxide emissions
Currently the greater part of the ethanol is used for low-level blending
into petrol
Using ethanol in diesel engines would bring about two major benefits:
Alleviate the shortage of middle distillates
Enable the use of ethanol with high engine efficiency
6 6
Scania ethanol engine
Scania DC9 E02 270 EEV
Model year 2011
5 cylinders
Displacement: 8.9 dm3
Compression ratio 28:1
(corresponding diesel engine 18:1)
Power: 198 kW / 1900 rpm
Torque: 1200 Nm / 1100-1400 rpm
Unit injectors, EGR, oxidation catalyst
However, the engine was tested w/o catalyst
Emission level Euro5/EEV
Additional fuel injectors were installed into the intake manifold
7 7
Instrumentation
For emission measurements, the apparatus corresponds to the
requirements of the European Directive 1999/96/EC on emission
measurements of heavy-duty engines
However, as a steady-state engine dynamometer was used, the
measurements were basically carried out using the European Steady
Cycle (ESC) procedure
Emissions of unburned alcohol and aldehydes were measured using
an FTIR instrument.
8 8
Test programme
The objectives of the test programme were to test:
Three alternative additive packages, all approved by Scania
Three different ethanol water concentrations (appr. 0, 5 and 10 %
water by weight)
Two fuels containing methanol; one blend of ethanol and methanol
and neat methanol
Whether injection of fuel into the manifold would facilitate ignition
on the main fuel shot
It must be pointed out that Scania doesn’t approve the use of methanol
containing fuels in its ethanol engine.
9 9
Test programme
Performance indicators monitored included, among other things:
Energy consumption
Carbon dioxide (CO2) emission
Regulated emissions (carbon monoxide CO, unburned
hydrocarbons HC*, nitrogen oxides NOx, particulate matter PM)
Unregulated emissions (unburned alcohol, aldehydes)
Ignition delay and heat release
*When running on alcohols, the hydrocarbon result is not accurate. However, the
HC values can with caution be used for fuel to fuel comparisons.
10 10
Test fuels
Density Ethanol H2O Methanol Carbon Hydrogen LHV
kg/m3 mass-% mass-% mass-% mass-% mass-% MJ/kg
Fuel 1 818,50 88,90 5,70 0,10 48,80 13,10 24,90
Fuel 2 813,90 90,50 5,52 0,50 47,80 13,30 24,70
Fuel 3 819,10 88,70 5,80 0,50 47,20 12,60 25,00
Fuel 4 804,40 92,30 0,44 0,10 49,60 12,50 26,80
Fuel 5 831,80 84,00 10,09 0,10 45,10 12,40 23,90
Fuel 6 819,50 57,00 5,14 28,70 43,20 12,30 23,20
Fuel 7 807,90 3,20 0,32 87,90 37,70 12,10 20,40
11 11
Differences in energy consumption within the measurement accuracy
Energy consumptions has been calculated using the analysed LHVs
(lower heating values)
0% 1% 2% 1% 1% -1 %
0,01,02,03,04,05,06,07,08,09,0
10,0C
on
sum
pti
on
, [M
J/kW
h]
Energy consumption, ESC test cycleFuels 4-7 with additive 1
12 12
0% 0% 0% 0% -1%-2 %
0
100
200
300
400
500
600
700
800Em
issi
on
, [g/
kWh
]
CO2 emission, ESC test cycleFuels 4-7 with additive 1
13 13
EEV emission limit for CO emission is 1.5 g/kWh (ESC test cycle)
Engine was measured without catalyst
-8% -6%+10%
-7%
-24%
-54%
0,0
0,2
0,4
0,6
0,8
1,0Em
issi
on
, [g/
kWh
]
CO emission, ESC test cycleFuels 4-7 with additive 1
14 14
EEV emission limit for HC emission is 0.25 g/kWh (ESC test cycle)
Engine was measured without catalyst
0% -1% -6% 2-6%
-29 %
0,0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8Em
issi
on
, [g/
kWh
]
HC emission, ESC test cycleFuels 4-7 with additive 1
15 15
EEV emission limit for NOx emission is 2.0 g/kWh (ESC test cycle)
NOx emission with Fuel 7 is most likely affected by the extended injection times
+2% +4% +10% -3% -2%
+23 %
0,0
0,5
1,0
1,5
2,0
2,5
3,0Em
issi
on
, [g/
kWh
]
NOx emission, ESC test cycle
Fuels 4-7 with additive 1
16 16
EEV emission limit for PM emission is 20 mg/kWh (ESC test cycle)
PM emission with methanol fuels is high
No visible soot on the filters so the result must be an indication
of semivolatile components or artifacts
-4 -9% -4% 0 +16%
+67 %
05
101520253035404550
Emis
sio
n, [
mg/
kWh
]
PM emission, ESC test cycleFuels 4-7 with additive 1
17 17
Summary of fuel comparison
Engine operated “equally and normally” with fuels 1-6
Equal energy consumption with all fuels
No real differences between additive packages could be found
The normal dosing of ignition improver additive is sufficient for stable engine
operation in all conditions
Leaving out the water increases both CO and NOx emissions, whereas adding
water reduces both these emissions marginally (in the case of ethanol)
Some effects of methanol on emissions and cylinder pressure
All in all the testing shows that the direct injection ethanol engine concept has
some built-in multifuel capabilities
18
Can the need for
additive be reduced?
19 19
Intake manifold injection & amount of ignition
additive
VTT tested an idea for enhancing the start of combustion
A small amount of ethanol is injected into intake manifold for
shortening the ignition delay
Would it be possible to decrease the amount of ignition additive?
A sequential 5-point injection system was added to Scania engine for
injecting fuel to the intake manifold
The system would not require an additional fluid, just a relatively simple
low-pressure injection system
20 20
Implementation of the idea
A sequential 5-point injection system was added to Scania engine for
injecting fuel to the intake manifold
Commercial “open” ECU was used to control the system
21 21
Measurements with the intake manifold injection
Test runs with fuels having a different additive levels were performed with
and without intake manifold fuel injection
When additive level was decreased to ¼ compared to commercial ED95
fuel, a clear difference with and w/o intake manifold injection was found out
Without intake manifold injection
1800 rpm / 25% load With intake manifold injection
1800 rpm / 25% load
22 22
Measurements with the intake manifold injection
Crank angle location for 10% heat release value indicates the differences in
start of combustion
23 23
Conclusions – intake manifold injection
Intake manifold injection was tested at high rpm and low load, the
conditions most critical for ignition
Intake manifold injection did indeed facilitate ignition of the fuel
In the preliminary tests using intake manifold injection increased overall
fuel consumption
Further testing to optimise, e.g., amount of pilot fuel and timing of main
fuel injection, is needed to really show the potential of the concept
In a common-rail engine pre-injection could be realised without
additional hardware
24 24
Acknowledgements
DTU Technical University of Denmark serves as operating agent and
coordinator of the IEA Advanced Motor Fuels project “Annex 46:
Alcohols fuels for diesel engines”
The work reported here is Finland’s contribution to this project
VTT received technical support from Scania and financial support from
North European Oil Trade NEOT and St1.
Recommended