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EPA Compliant Fuel Systems IBEX Sep 28, 2010 Sean Whelan P.E. 1. Agenda. Which diurnal system should I choose What is Automatic Shut off/no spit back & how do I meet it Automatic shut off in cars & trucks Venting and Thermal Expansion Engine Performance & Fuel Line Pressure Drop
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EPA Compliant Fuel Systems IBEX Sep 28, 2010 Sean Whelan P.E. 1
Agenda • Which diurnal system should I choose • What is Automatic Shut off/no spit back & how do I meet it • Automatic shut off in cars & trucks • Venting and Thermal Expansion • Engine Performance & Fuel Line Pressure Drop • Safety Considerations • Technical Considerations 2
Which Architecture do I choose? Diurnal Systems (all) • Can I fit a new tank with diurnal components mounted? • How do I maintain accessibility of all attachments? Carbon Canister System • Can I fit a carbon canister in my boat? • How do I prevent liquid gas and water from entering the canister? Pressure Release System • Can I prevent fuel line from pressurizing or do I need rigid fuel lines? • Can my new tank assembly withstand the pressure cycles over time? • Is there room for my tank to swell under pressure without contacting deck or hull? • Do I have sufficient pressure drop budget in my engine(s)?
Automotive Fuel System • Nozzle shut off feature
Automotive Fuel System • Nozzle shut off feature
Automotive vs. Marine Fuel Systems Automotive System -Fittings below topmost surface -Active purge canister system -Filling event emission limits -Fuel pump in tank Marine System -All fittings on topmost surface -Tank must pass fire test -Passive purge canister only -Fuel pump on engine 7
Refueling Considerations • How will the system handle high and low RVP fuels? • How will the system handle high and low temperature refueling events? • Will my boat be compatible with marina fuel fills of larger sizes? • Will my customer be safe after filling boat with a jerry can?
Venting -Components must be dry -Must vent freely
Ullage Ullage Reservoir *http://dictionary.reference.com/browse/ullage
Tank Modeling Tank Body Tank Volume (281.80 Ga) (93% of Complete Tank Volume) Min Distance Max Distance
0.3° STATIC POSITION FRONT DOWN (4°) RIGHT DOWN (2°) Tip/Vent Study LEFT Tank Orientation (Static) REAR FRONT RIGHT Tank Tip Study At (98% of Complete Tank Volume) LEFT DOWN (2°) REAR DOWN (4°)
REAR & LEFT DOWN FRONT & LEFT DOWN REAR & RIGHT DOWN FRONT & RIGHT DOWN Tip/Vent Study FUEL ORIENTATION AT VARIOUS TIP STUDY ANGLES LAYERED OVER EACHOTHER. Iso View Tank Tip Study – Vapor Space available in various combinations
Venting Considerations • How does my fuel system create ullage? • How does my system allow for venting at ABYC H24 angles? • What happens at angles beyond H24? • How do I prove that my fleet vents safely for every model?
Engine Performance • Fuel Line Pressure Drop • What different engines may end up on boat model? • What are the engine manufacturers vacuum requirements?
Requires 12” of anti-siphon protection (or stop valve) Elevation “X” to Engine Current Anti Siphon Engine Fuel line vacuum = X + 12”gasoline + hose routing restriction Ex. = 32”gasoline+ 12”gasoline+ 9”gasoline= 53”gasoline (1.47psi, 10kPa, 3inHg) 12”
Requires 12” of anti-siphon protection (or stop valve) Elevation “X” to Engine EPA compliant Anti Siphon Engine Fuel line vacuum = X + 12”gasoline + hose routing restriction + Y Ex. = 32”gas+ 12”gas+ 9”gas+ 10”gas= 63”gasoline (1.75psi, 12kPa, 3.6inHg) Diurnal Vacuum/ restriction of “Y” in-gasoline 12”
Requires 30” of anti-siphon protection (or stop valve) Elevation “X” to Engine EPA compliant Anti SiphonUllage Tank Example Engine Fuel line vacuum = X + 30”gasoline + hose routing restriction + Y Ex. = 32”gas+ 30”gas+ 9”gas+ 10”gas= 81”gasoline (2.25psi, 15.5kPa, 4.6inHg) Ullage Tank 18” Diurnal Vacuum/ restriction of “Y” in-gasoline 12”
May require rigid fuel lines to engine or May require pressure management device Special Note Regarding Fuel Line (for PRV Diurnal Systems)
Engine considerations • What different engines may end up on boat model? • What are the engine manufacturers vacuum requirements? • What is elevation of engine hook ups? • Do I have sufficient pressure drop budget for the EPA Diurnal system I want? • What is the tank vacuum with EPA diurnal system? • What is the additional fuel pressure drop with EPA diurnal system?
Safety Considerations • What is preventing over pressurization of the tank? • What safety methods and strategies prevent fuel from entering into the bilge? • What happens when a customer fills a tank in an extreme circumstance beyond ABYC & EPA specifications? (i.e. 65°F temperature swing) • Will the new fuel systems allow engines to operate properly under all conditions? • Is there a single component that can cause system to fail or is there redundancy built in?
Technical Considerations • Refueling with no spit-back • Engine fuel line pressure drop • Hot Fuel Handling • Extreme Vessel angles/ attitudes • Jerry Can filling event • Non-automatic nozzle filling event • Vapor Condensation/ liquid accumulation • Expected CARB requirements • Pressure Lifecycle • Fill Level Repeatability 22
Summary/ Review • Diurnal • Refueling • Venting • Engine Compatibility 23
Questions? 24
Appendix 25
Diurnal Emissions • What is diurnal? • What are diurnal emissions? • How are systems built to reduce emissions ? • Carbon Canister • Pressure Release Valve