Testing of various fuel and additive options in a compression-ignited heavy-duty alcohol engine

Transcription

1 Testing of various fuel and additive options in a compression-ignited heavy-duty alcohol engine 2015 Polttomoottori- ja turboteknologian seminaari Espoo, Timo Murtonen, Nils-Olof Nylund, Mårten Westerholm & Christer Söderström (VTT) Timo Huhtisaari (NEOT) Gurpreet Singh (DTU)

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 2

3 Bioruukki Pilot Centre Enabler of national bioeconomy and cleantech strategies, platform for circular economy based activities Unique combination of FOUR technology platforms 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; highconsistency processing 4. Solar Centre - BIO-infra 3 Storage and distribution systems to solar energy 3

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 4

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 5

6 Scania ethanol engine Scania DC9 E EEV Model year cylinders Displacement: 8.9 dm 3 Compression ratio 28:1 (corresponding diesel engine 18:1) Power: 198 kw / 1900 rpm Torque: 1200 Nm / 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 6

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. 7

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. 8

9 Test programme Performance indicators monitored included, among other things: Energy consumption Carbon dioxide (CO 2 ) emission Regulated emissions (carbon monoxide CO, unburned hydrocarbons HC *, nitrogen oxides NO x, 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. 9

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 10

11 Consumption, [MJ/kWh] 10,0 9,0 8,0 7,0 6,0 5,0 4,0 3,0 2,0 1,0 0,0 Energy consumption, ESC test cycle Fuels 4-7 with additive 1 0% 1% 2% 1% 1% -1 % Differences in energy consumption within the measurement accuracy Energy consumptions has been calculated using the analysed LHVs (lower heating values) 11

12 Emission, [g/kwh] CO2 emission, ESC test cycle Fuels 4-7 with additive 1 0% 0% 0% 0% -1% -2 % 12

13 Emission, [g/kwh] 1,0 0,8 0,6 CO emission, ESC test cycle Fuels 4-7 with additive 1 +10% -8% -6% -7% -24% 0,4-54% 0,2 0,0 EEV emission limit for CO emission is 1.5 g/kwh (ESC test cycle) Engine was measured without catalyst 13

14 Emission, [g/kwh] 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0,0 HC emission, ESC test cycle 0% -1% -6% 2 Fuels 4-7 with additive 1-6% -29 % EEV emission limit for HC emission is 0.25 g/kwh (ESC test cycle) Engine was measured without catalyst 14

15 Emission, [g/kwh] NOx emission, ESC test cycle 3,0 2,5 2,0 +2% +4% +10% -3% -2% Fuels 4-7 with additive % 1,5 1,0 0,5 0,0 EEV emission limit for NO x emission is 2.0 g/kwh (ESC test cycle) NOx emission with Fuel 7 is most likely affected by the extended injection times 15

16 Emission, [mg/kwh] PM emission, ESC test cycle Fuels 4-7 with additive % -4% 0 +16% +67 % 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 16

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 NO x 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 17

18 Can the need for additive be reduced? 18

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 19

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 20

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 21

22 Measurements with the intake manifold injection Crank angle location for 10% heat release value indicates the differences in start of combustion 22

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 23

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. 24