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EPA Compliant Fuel SystemsIBEX Sep 28, 2010

Sean Whelan P.E.

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Agenda

1. Which diurnal system should I choose

2. What is Automatic Shut off/no spit back & how do I meet it

3. Automatic shut off in cars & trucks

4. Venting and Thermal Expansion

5. Engine Performance & Fuel Line Pressure Drop

6. Safety Considerations

7. Technical Considerations

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)?

What Is Automatic Shut Off

Automotive Fuel System– Nozzle shut off feature

Automotive Fuel System– Nozzle shut off feature

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Automotive vs. Marine Fuel Systems

Marine System

-All fittings on topmost surface

-Tank must pass fire test

-Passive purge canister only

-Fuel pump on engine

Automotive System

-Fittings below topmost surface

-Active purge canister system

-Filling event emission limits

-Fuel pump in tank

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?

-Components must be dry

-Must vent freely

Venting

Ullage Reservoir

Definition:

The volume by which a liquid container falls short of being full*

Ullage

*http://dictionary.reference.com/browse/ullage

TANK VOL (cu.in.) TANK VOL ( Gallons)

Min Distance Between Tank Top surface and Fuel (in) (93% OF TOTAL INTERIOR VOLUME)

Max Distance Between Tank Top surface and Fuel (in) (93% OF TOTAL INTERIOR VOLUME)

Tank Wall Thickness (in)

69997.3857 303.01 1.1752 1.4333 0.25

TOTAL INTERIOR VOLUME OF TANK

FLUID VOLUME OF TANK (93% OF TOTAL INTERIOR VOLUME)

FLUID VOLUME OF TANK (98% OF TOTAL INTERIOR VOLUME)

cu. in. 69997.3857 65097.5687 68597.4380

US Gallons 303.01 281.80 296.95

Tank Volume (281.80 Ga)(93% of Complete Tank Volume)

Tank Body

Min Distance

Max Distance

Tank Modeling

Tank Orientation (Static)

Tank Tip Study At (98% of Complete Tank Volume)

FRONT DOWN (4°) RIGHT DOWN (2°)

LEFT DOWN (2°)

STATIC POSITION0.3°

RIGHT

LEFT

FRONTREAR

REAR DOWN (4°)

Tip/Vent Study

FUEL ORIENTATION AT VARIOUS TIP STUDY ANGLESLAYERED OVER EACHOTHER.

Iso View

Tank Tip Study – Vapor Space available in various combinations

FRONT & LEFT DOWN

FRONT & RIGHT DOWN

REAR & LEFT DOWN

REAR & RIGHT DOWN

Tip/Vent Study

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

• What different engines may end up on boat model?

• What are the engine manufacturers vacuum requirements?

– Fuel Line Pressure Drop

Current Anti Siphon

12”

Requires 12” of anti-siphon protection (or stop valve)

Elevation “X” to Engine

Engine Fuel line vacuum = X + 12”gasoline + hose routing restriction

Ex. = 32”gasoline+ 12”gasoline+ 9”gasoline= 53”gasoline (1.47psi, 10kPa, 3inHg)

EPA compliant Anti Siphon

12”

Requires 12” of anti-siphon protection (or stop valve)

Elevation “X” to Engine

Engine Fuel line vacuum = X + 12”gasoline + hose routing restriction + YEx. = 32”gas+ 12”gas+ 9”gas+ 10”gas= 63”gasoline (1.75psi, 12kPa, 3.6inHg)

Diurnal Vacuum/ restriction of “Y” in-gasoline

EPA compliant Anti SiphonUllage Tank Example

12”

Requires 30” of anti-siphon protection (or stop valve)

Elevation “X” to Engine

Engine Fuel line vacuum = X + 30”gasoline + hose routing restriction + YEx. = 32”gas+ 30”gas+ 9”gas+ 10”gas= 81”gasoline (2.25psi, 15.5kPa, 4.6inHg)

Diurnal Vacuum/ restriction of “Y” in-gasoline

Ullage Tank18”

Special Note Regarding Fuel Line (for PRV Diurnal Systems)

May require pressure management device

May require rigid fuel lines to engine

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?

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Technical Considerations1) Refueling with no spit-back

2) Engine fuel line pressure drop

3) Hot Fuel Handling

4) Extreme Vessel angles/ attitudes

5) Jerry Can filling event

6) Non-automatic nozzle filling event

7) Vapor Condensation/ liquid accumulation

8) Expected CARB requirements

9) Pressure Lifecycle

10) Fill Level Repeatability

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Summary/ Review

1. Diurnal

2. Refueling

3. Venting

4. Engine Compatibility

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Questions?

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Appendix

Diurnal Emissions• What is diurnal? • What are diurnal emissions?• How are systems built to reduce emissions ?

– Carbon Canister– Pressure Release Valve

Carbon Canister Fuel System

Pressure Relief Fuel System