WÄRTSILÄ 2-STROKE GAS. Ship Power March 2013

Transcription

1 WÄRTSILÄ 2-STROKE GAS Ship Power March Wärtsilä

2 Natural Gas as marine fuel 60s-70s Today -25% Emission values [%] stroke DF results CO 2-85% -100% NO x SO x -99% : low pressure loop scavenged engine 6RD76 tested in Winterthur 7RNMD90 installed in m 3 LNG-carrier MV Venator in 1972 Particulates Dual-Fuel engine in gas mode Diesel engine 0 2 Wärtsilä

3 Basic concept (2 stroke low pressure) Pre-mixed lean-burn combustion Principles: Engine operating accordingly to Otto process Injection of gas at mid-stroke. Low pressure gas injection (<10 bar) sufficient High impact on NO X reduction Meets IMO Tier III without after treatment Scavenging Compression/ gas admission Ignition expansion 3 Wärtsilä

4 Other concept (2 stroke high pressure) Direct injection, diffusion combustion Principles: Engine operating accordingly to Diesel process Injection of gas close to TDC. Air is completely compressed and, therefore, high pressure gas injection (300 bar) is required. No significant NO X reduction Scavenging/ compression Pilot & HP gas injection Expansion Requires SCR or EGR (not proven) in order to meet IMO Tier III levels 4 Wärtsilä

5 Otto & Diesel cycle: effects on NO X Big temperature difference NOx formation! Diesel, max flame temp. Otto, max flame temp. 5 Wärtsilä

6 Technical features Gas admission Gas admission system 2 x GAV (gas admission valve) per cylinder GAV actuated by hydraulically fast-switching solenoid valves Hydraulic power supply from exhaust valve servo oil system 6 Wärtsilä

7 Technical features Pilot fuel system Pilot fuel system Pilot fuel utilized for ignition (as in four-strokes DF engines) Micro pilot valves utilization. Pilot fuel consumption < 1% of BSFC Pre-chamber technology for best ignition and combustion stability Fuel supply based on common-rail technology (as in four-strokes DF engines) Pilot fuel injectors Pre-chamber 7 Wärtsilä

8 Technical features Pilot fuel system Pilot fuel system Single fuel oil pump serving all cylinders (common-rail technology) Filters and pressure regulation included Pilot fuel pump can be electrically or mechanically driven UNIC 8 Wärtsilä

9 Technical features Gas feed system Gas Valve Unit (GVU) Wärtsilä standardized and proven design applied Pressure regulation, gas filtering and safety valves included Emergency venting procedure and leakage test features introduced 9 Wärtsilä

10 Technical features Automation Engine automation and control system UNIC based control system Individual control of combustion related parameters Safety functions related to gas operation included Exhaust valve (Pilot fuel pressure) Control system Gas pressure Engine speed/ca-signal Engine stop signal Gas duration Test cylinder running on gas Pilot fuel injectors 2x Gas admission valves Pilot fuel injector Gas admission valves Exhaust valve drive 10 Wärtsilä

11 Performance targets (<10bar) Operational features Dual Fuel operation (HFO,Gas) Low gas feed pressure Tier III compatible in gas mode without exhaust gas after treatment Pilot fuel required when in gas mode 1% of BSFC at 100% engine load Idling speed on gas operation (Verification required in all cylinder operation) 11 Wärtsilä

12 Project overall time schedule Project activities Pre-study Concept evaluations Product requirement spec. Technology development Simulations & design for 1 cyl Engine tests 1 cyl Industrialisation 6 cylinder engine design Full scale engine tests Introduction Concept release Pilot installation data release: information release installation manual (MIM) Full scale engine testing: customer demo (lab engine) validation at licensee First sailing validation Design, development, preparation Engine testing 12 Wärtsilä 2014

13 2-stroke gas engine development 2-stroke gas engine development based on vast experience from 4-stroke dual fuel engines/installations 13 Wärtsilä 4-stroke dual fuel references: Power plants, Merchant, Offshore, Cruise & Ferry, Special ~190 installations > 5,000,000 running hours

14 Minimum gas quality requirements Property Unit Value Lower heating value (LHV), min 1) MJ/m 3 N 2) 28 Methane number (MN), min 3) 90 (IMO Tier 1) 80 (IMO Tier 2) Methane (CH 4 ), min % volume 70 Hydrogen sulphide (H 2 S), max % volume 0.05 Hydrogen (H 2 ), max 4) % volume 3 Ammonia, max mg/m 3 N 25 Chlorine + Fluorines, max mg/m 3 N 50 Particles or solids at engine inlet, max mg/m 3 N 50 Particles or solids at engine inlet, max size um 5 Gas inlet temperature C 0 60 Water and hydrocarbon condensates at engine inlet not allowed 5) 1) The required gas feed pressure is depending on the LHV (see section Gas feed pressure in chapter Fuel system). 2) Values given in m³ are at 0 C and kpa. 3) The methane number (MN) is a calculated value that gives a scale for evaluation of the resistance to knock of gaseous fuels. Above table is valid for a low Methane Number optimized engine. Minimum value is depending on engine configuration, which will affect the performance data. However, if the total content of hydrocarbons C4 and heavier is more than 1% volume Wärtsilä has to be contacted for further evaluation. 4) Hydrogen content higher than 3% volume has to be considered project specifically. 14 Wärtsilä

15 BSFC characteristics for W5X72 LNG BSFC [g/kwh] Engine load [%] LNG consumption [g/kwh] Pilot fuel MDO [g/kwh] Pilot fuel MDO [g/kwh] High efficiency turbocharger ABB A100 or MET MB / ISO, LCV of kj/kg Tol. +5% between 85 to 100% load, +6% between 65 to 84% load, +7% between 50 to 64% load 15 Wärtsilä

16 Fuel Gas Handling System Low pressure compressor set Qh Heater LNG FUEL GAS MODULE Evaporator Qv LNG tank Low pressure feed pump 16 Wärtsilä

17 WÄRTSILÄ 2-STROKE GAS RT-flex engine conversion to gas (DF) RT-flex RT-flex (Dual Fuel) 17 Wärtsilä Wärtsilä 2-stroke / Gas Engine /

18 RT-flex engine conversion to gas Exhaust valve CCM-20 (Additional) 2/3 Pilot fuel injectors & Pre-chambers Replacement of cylinder cover Cylinder 2 x Gas Admission Valves (GAV) Extra machining of cylinder liner 2 x Gas Rail PRELIMINARY MDO supply unit Support platform for MDO SU MDO pipes to injectors 18 Wärtsilä Wärtsilä 2-stroke / Gas Engine /

19 RT-flex engine conversion to gas Action Component and description Quantity Existing components to be replaced Cylinder cover 1 per cylinder Existing RT-flex parts to be modified New fuel system related parts Machining cylinder liner for gas admission valves (might also need replacement) MDO pump unit for fuel pilot injectors MDO pipes to fuel pilot injectors 1 per cylinder 1 per engine 1 system per engine Ignition system Pilot fuel injectors Pre-chambers 2/3 per cylinder 2/3 per cylinder Turbocharging & Scavenge air system parts Waste gate on the turbocharger By-pass valve on the turbocharger (possibly) 1 per engine 1 per engine Gas admission valves 2 per cylinder Gas admission system components Servo oil piping to gas admission valves 2 per cylinder Gas rails (piping) 2 per engine CCM-20 1 per cylinder New automation system related parts (Installed automation system dependant) Booster Cylinder pressure sensor 8 per cylinder 1 per cylinder Knocking sensor 1 per cylinder Other Assembly, relocation of pipes, sensors, small components. - PRELIMINARY 19 Wärtsilä Wärtsilä 2-stroke / Gas Engine /