Dual-fuel RCCI combustion Project leader: Prof. Ingemar Denbratt PhD student: Zhiqin Jia Project start date: 30 Jan 2016 Project end date: Feb 2018 Program: CERC Project funding: 2,158,000SEK
Zhiqin Jia Background & goals Experimental setup Methodology Results Conclusions Outline
Zhiqin Jia Background Dual-fuel RCCI (Reactivity Controlled Compression Ignition) combustion concept gives quite promising results (efficiency and emissions). Limited research work regarding althernative fuels a) Kokjohn, S.L., Hanson, R.M., Splitter, D.A., Reitz, R.D., Fuel Reactivity Controlled Compression Ignition (RCCI): a Pathway to Controlled High- Efficiency Clean Combustion, Int. J. Engine Res. 12 (2011) 209-226, 2011 b) Kokjohn, S.L., Hanson, R.M., Splitter, D.A., Kaddatz, J., Reitz, R.D., Fuel Reactivity Controlled Compression Ignition (RCCI) Combustion in Light- and Heavy-Duty RCCI Engines, SAE combustion. Technical Paper 2011-01-0357. c) Splitter, D. A., Wissink, M. L., Reitz, R.D., RCCI Engine Operation Towards 60% Thermal Efficiency, SAE Technical Paper: 2013-01-0279. Dual-fuel multi-dimensional CFD model could help understanding combustion details. a) Dahodwala, M., Joshi, S., Koehler, E., Franke, M., Experimental and computational analysis of diesel-natural gas RCCI combustion in heavy-duty engines, SAE Technical Paper: 2015-01-0849. b) Demsey, A.B., Ryan Walker, N., Reitz, R.D., Effect of piston bowl geometry on dual fuel reactivity controlled compression ignition (RCCI) in a light-duty engine operated with gasoline/diesel and methanol/diesel, SAE Technical Paper 2013-01-0264. c) Derek, D. E., Demsey, A.B., Reitz, R.D., Heavy-duty RCCI operation using natural gas and diesel, SAE Technical Paper: 2012-01-0379.
Zhiqin Jia Goals To investigate dual-fuel (natural gas/diesel) RCCI fast combustion in a heavy duty Diesel engine. Using multi-dimensional CFD model to understand natural gas/diesel RCCI combustion details. To evaluate direct injection of high-octane fuel (methanol) on RCCI combustion.
Zhiqin Jia Experimental setup Volvo D13 single cylinder engine Engine type Bore (mm) 131 Stroke (mm) 158 Connecting rod (mm) Compression ratio (-) Number of valves 4 Single cylinder AVL 501 267.5 16.8
Zhiqin Jia Methanol port injector Methanol Delphi F3 Methanol Delphi F2 Methodology SOI [ÅTDC] -350-358 -100 Methanol injection PFI DI(F3) 7-hole DI(F2) 2-hole Methanol Diesel -360-300 -240-180 -120-60 0 Crank angle [ ATDC] Diesel injection profile (electrical signal) SOI=-48 ATDC SOI =-15 ATDC
Cylinder pressure [bar] Soot [g/kwh] NOx [g/kwh] CA50 [ ATDC] η thermal [%] Zhiqin Jia Results Effect of Diesel pilot SOI timing Port & Delphi F3 Delphi F2 injectors injector Main SOI -15-15 [ ATDC] Pilot duration 6.75 8.91 [degree] Main duration 4.86 6.41 [degree] Equivalent ratio 0.38 0.43 Methanol 65.2-65.6 53.3-53.8 substitution -43 ATDC percentage [%] F2 F3 Port IMEP 100 [bar] ~5 340 ~5 Engine 80 speed 1500 280 1500 (rpm) 60 220 Intake 40 60 160 60 20 100 temperature 0 40 [ C] -20-20 -30-20-10 0 10 20 30 40 Crank angle [ ATDC] Apparent heat release rate [J/ CA] 48 F2 F3 Port 44 40 6 2-2 16 12 8 0,15 0,1 0,05 0-50 -45-40 -35 Pilot SOI [ ATDC]
Methanol/Diesel vs pure Diesel at various loads Results Zhiqin Jia
Conclusions Effect of Diesel pilot SOI on combustion and emissions were limited. F3 and port configurations had very similar combustion patterns but not F2 configuration. Both methanol configurations showed potential greenhouse gas reduction for all the load points compared with pure Diesel case. Port configuration maintained both ultra-low NO x and soot at 12 bar IMEP but not F2 configuration. Zhiqin Jia The combustion of direct injection of methanol didn t show any improvement compared with port methanol injection.
Zhiqin Jia Thank you for your attention
Cylinder pressure [bar] Zhiqin Jia 100 80 60 40 20 0-20 -48 ATDC F2 F3 Port 400 330 260 190 120 50-20 -30-20-10 0 10 20 30 40 Crank angle [ ATDC] Apparent heat releae rate [J/ CA]
NOx [g/kwh] Soot [g/kwh] CH 3 OH [g/kwh] η thermal [%] Zhiqin Jia Effect of main SOI timing Results Port & Delphi F3 injectors Delphi F2 injector Pilot SOI -48-48 [ ATDC] Main SOI -15-15 [ ATDC] Equivalent ratio 0.38 0.43 Methanol 65.5-66.9 52.9-53.7 substitution percentage [%] IMEP [bar] ~5 ~5 Intake temperature [ C] 60 60 46 F2 F3 Port 43 40 8 5,5 3 5,00E-02 2,50E-02 0,00E+00 20 12,5 5 0,4 0,5 0,6 0,7 0,8 0,9 Main/pilot duration ratio
Soot [g/kwh] NOx [g/kwh] CA50 [ ATDC] η Thermal [%] Zhiqin Jia Results Effect of Diesel main SOI timing 47 F3 Port F2 44 41 7 2-3 20 12,5 5 0,10 0,05 0,00-20 -18-16 -14-12 Main SOI [ ATDC]