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Comparison MDT gas engines. Niels Kjemtrup LDF. Gas engine working principles. Fundamentals: Combustion principles for Gas Engines. Figures based on: Mollenhauer, K., Tschöke , H., (2007): Handbuch Dieselmotoren. 3. Auflage, Springer Verlag, Berlin, Heidelberg, New York. .
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Comparison MDT gas engines • Niels Kjemtrup LDF
Gas engineworkingprinciples Fundamentals: Combustion principles for Gas Engines Figuresbased on: Mollenhauer, K., Tschöke, H., (2007): Handbuch Dieselmotoren. 3. Auflage, Springer Verlag, Berlin, Heidelberg, New York
What do weknowfrom 4-stroke engines Engine Emissions – NOX (SOX, PM) NOX: • Lean burn Otto-cycle low NOx • Diesel-cycle combustion high NOx NOX [g/kWh] SOX and Particle Matters (PM): • Emissions of SOX and PM depend on the pilot fuel oil consumption: • GI: 1-5% pilot (of MCR) • DF: ~1% pilot (of MCR) • G: No Pilot Engine Load [%] 51/60DF (MZ 80) 4T50ME-GI-X 48/60CR (HFO) 35/44G
What do weknowfrom 4-stroke engines Engine Emissions – Greenhouse Gas (GHG) GHG[g/kWh] 51/60DF (MZ 80) 48/60CR (HFO) http://www.enwin.com/kids/conservation/greenhouse_effect.cfm S70ME-GI, L1 35/44G Engine Load [%] Definition: All gases which influence the greenhouse effect given as mass equivalent to CO2 • For gas engines, mainly CO2 and CH4 emissions are relevant • GHG = CO2 + 25 * (4/3) * CH4 as C1
What do weknowfrom 4-stroke engines Engine Efficiency • Engine efficiency without preconditioning of fuel gas supply ηmech 51/60DF (MZ 80) S70ME-GI, L1 35/44G Engine Load [%]
DF: From Gas Tank to Engine Fuel Gas Supply System DF Engine Cyrogenic pump LP Compressor 10 bar 45 dg. C LP Compressor Varporizer 3337813.2011.05.18 (LB/LRJ)
ME-GI: From Gas Tank to Engine Fuel Gas Supply System ME-GI Engine 300 bar 45oC 3337813.2011.05.18 (LB/LRJ)
Design Examples: 4T50ME-GI-X (Gas Diesel engine) • Connection block for: • Gas inlet/outlet, Hydraulic oil, Sealing oil, Hydraulic oil drain, Oil drain, Low pressure oil, Double wall ventilation system
DF / G - System Relatively simple low pressure gas supply Mainly easy to change maintenance components w/o further adjustment: Spark plug Pilot injector Gas valves Pre-Chamber Check Valve ... Few pipes necessary to assure full functionality: Gas inlet Pilot fuel inlet (DF) or pilot gas inlet (G) Pilot fuel drain (DF) Maintenance of Gas Systems on Engine GI- System • 300bar high pressure gas supply • All pipes connected to a fixated distribution block to ease maintenance and to assure full functionality: • Gas inlet • Gas outlet • Hydraulic oil • Sealing oil • Hydraulic oil drain • Oil drain from window/shutdown valve and gas injection valves • Low pressure oil • Double wall ventilation system • Both engines can be serviced by experienced crew & trained service staff
25 g/kWh
Pilot Fuel for ignition • Gas injection in top, • Shortly after Pilot injection • ”Diesel combustion”
Pro’s • High efficiency (better than Diesel) • High efficiency at all loads • Stable and reliable ”Diesel Combustion” • No methane slip • Small gas volumes • Fully verified • Con’s • High pressure supply system • Needs EGR/SCR for Tier III
GI • IMO Tier II Compliance in combination • With SCR/EGR • Safe and reliable diesel operation • No knocking • No Derating • No special requirements to • Methane Quality • Dual Fuel (NG/HFO)Capability without • methane slip Yes! Yes! Yes!
Tier III Propulsion System on GasAll use Same Tank system • 4T DFDE: • Con’s / Pro’s • Big efficiency losses • Derating, i.e. largerengine • Tier III onlyon gas • LP FGSS • Efficiencyloss (gear) • Derating, i.e. largerengine • Needgensets DF • Tier III onlyon gas • LP FGSS • Derating, i.e. largerengine • Needgensets DF • Tier III onlyon gas • LP FGSS • Need HP/LP FGS5 • Needgensets DF • Noderating, i.e. save cyl. • Need EGR/SCR • Tier III onanyfuel • Best efficiency Tank LP FGSS DFDE Train, more power need 4T DF Mech: DFDE gensets Tank LP FGSS DF Mech. ,eng. + gear 2T DF LP: DFDE gensets Tank LP FGSS LP Low Speed; + 1-2 cyl. 2T DF HP: DFDE gensets Tank HP/LP FGSS HP Low Speed + EGR/SCR
Complete GI Engine Program Available
The GI dual fuel engine has • exactly the same output as • the corresponding Diesel engine • The GI has in GI mode better • SFOC than in Diesel mode • Especially at par and low load • The GI engine in combination • With EGR/SCR is fully IMO Tier III • compliant in both NG and HFO • operation conditions Same as Diesel Betterthan Diesel Compilantwith IMO Tier III In combinationwith SCR/EGR
Design Modifications Diesel GI • Gas Admission System • Control system • Gas valves • Gas Block • Safety system