Future Powertrain Conference 2017 Advanced Ethanol-Diesel Dual-Fuel Combustion for Heavy-Duty Engines Vinícius Pedrozo* Prof. Hua Zhao Centre for Advanced Powertrain and Fuels - CAPF College of Engineering, Design and Physical Sciences
As one of America s governors has said, We are the first generation to feel the impact of climate change, and the last generation that can do something about it. Sources: https://www.youtube.com/watch?v=r7mxyzcfkb8; https://www.whitehouse.gov/the-press-office/2015/11/30/remarkspresident-obama-first-session-cop21. Source: http://climate.nasa.gov/effects. 2
Ethanol as an Alternative Fuel - Renewable; - Low carbon fuel; - Well established use in Brazil. Source: http://blog.mfrural.com.br/tag/cana-de-acucar Rape seed 60% reduction vs. fossil fuel comparator Biodiesel Hydrotreated vegetable oil (HVO) from rape seed Soybean Palm oil biodiesel Bioethanol Fossil Waste vegetable/animal oil Wheat ethanol Sugar beet ethanol Sugar cane ethanol Fossil fuel comparator Default GHG emissions (RED Annex V) ILUC IFPRI 2011 0 20 40 60 80 100 120 140 gco 2 eq / MJ Source: Adapted from Shell, Challenges and Fuels Options for Future HD Transportation, SAE 2016 HDDEC Symposium. 3
Research Motivation - Increasingly fuel energy demand and oil dependency; - Stringent emissions regulations. Global transportation demand (Million oil-equivalent barrels per day) 75 Global transportation demand by fuel (Million oil-equivalent barrels per day) 75 Other Natural gas Jet fuel 50 Commercial 50 Fuel oil Diesel 25 25 Light-duty road Gasoline 0 2000 2020 2040 0 2000 2010 2020 2030 2040 Source: Adapted from Exxon Mobil Corporation, The Outlook for Energy: A View to 2040. 4
Research Objectives - Research advanced dual-fuel combustion strategies; - Achieve efficient engine operation with low exhaust emissions (e.g. Euro VI compliant); - Maximise the use of ethanol in a heavy-duty diesel engine. Direct Injection of Diesel Port Fuel Injection of Ethanol 5
Single Cylinder Heavy-Duty Engine Parameter Bore x Stroke Connecting rod length Value 129 x 155 mm 256 mm Swept volume 2.026 dm 3 Geometric compression ratio 16.8:1 Max. in-cylinder pressure Piston type Diesel injection system Ethanol injection system 18 MPa Re-entrant bowl Bosch Common Rail, max. 220 MPa, 8 holes, 150 spray PFI Marelli IWP069, 300 kpa rel., 15 spray 6
Test Cell Diagram 7
Methodology - CDC vs. Dual-fuel; - Engine loads: 3 to 15 bar IMEP. - Engine speed: 1200 rpm. - Limitations: EGR rate 25%; PRR 20 bar/cad; COV_IMEP 3%; COV_Pmax 3%. 8
Methodology - Diesel injection timings for maximum net indicated efficiency; Up to 80% - Ethanol energy fractions for minimum ISNOx/ISsoot. Ethanol energy fraction = m ethanol LHV ethanol m ethanol LHV ethanol + m diesel LHV diesel 9
Combustion Control Pre- and main inj. near TDC at mid/high loads Split inj. (51/49) at mid load Early single inj. at light loads 10
Combustion Characteristics PRR 20 bar/cad Shorter and retarded combustion process Higher peak heat release 11
Exhaust Emissions Lower consumption of aqueous urea solution in the SCR system EGT below 200 C at 3 bar IMEP 53-84% lower NOx emissions Low levels of smoke 12
Exhaust Emissions EGT below 200 C at 3 bar IMEP Higher unburnt HC Higher CO emissions 13
Performance Crevice volumes + lower local in-cylinder gas temperatures/φ Lower combustion efficiencies High net indicated efficiencies 14
Summary - The introduction of a premixed charge of ethanol into a HD diesel engine was effective in reducing NOx emissions by up to 84%; - The adoption of optimum fuel injection strategies at each engine load was the key enabler for controlling the in-cylinder charge reactivity and PRR s; - Fuel flexibility combined with an efficient dual-fuel combustion and lower NOx emissions can decrease the engine running costs. 15
Thank you for your attention! vinicius.pedrozo@brunel.ac.uk hua.zhao@brunel.ac.uk 16