“In the name of supreme being”

DUAL‐FUEL ENGINES

Gathered by:Ali Eidi Ahmadabad

Ali Mohamadi RashtinAmin Mohamadi

Composition

1.Biomethane as vehicle fuel Energy Independency, Environmental benefits

2.Gas vehivle a brief history

3.Dual fuel, Technology, advantage and Disadvantage

Oil depedency

Limited supply of fossil fuel

• By 2025, we need to find, devolope and produce a volume of new oil and Gas that equal 8 out of every 10 barrels produced today.

Possible fuels

Advantages using CNG

• The most environmental friendly fuel

• Cost efficient• Up to 60 000 new jobs• Health benefits• Independency• One solution to several problems

• The ignition temperature for natural gas is higher than for gasoline and diesel fuel.

• Natural gas is lighter than air and will dissipate upward rapidly if a rupture occurs.

• Gasoline and diesel will pool on the ground, increasing the danger of fire.

• Compressed natural gas is non-toxic and will not contaminate groundwater if spilled.

Engine emission result

CNG lean burn fuel consumption

Disadvantage of biomethane

• New unreliable technology• Dangerous• Vehicle range• Fuel storage• Infrastructure costs• Ensuring sufficient supply.

Dangerous….

Some solvation for above problem

Those can be overcome by:• The proper design• Fuel management• Exhaust treatment

techniques

History

A brief history• There were many experiments

with gas engines in the 19th century but the first practical gas fuelled internal-combustion engine was built by the Belgian engineer Étienne Lenoir in 1860.

• However, the Lenoir engine suffered from a low power output and high fuel consumption.

• His work was further researched and improved by a German engineer Nikolaus August Otto, who was later to invent the first 4-stroke engine to efficiently burn fuel directly in a piston chamber.

• In August 1864 Otto met Eugen Langen who, being technically trained, glimpsed the potential of Otto's development, and one month after the meeting, founded the first engine factory in the world, NA Otto & Cie, in Cologne.

• In 1867 Otto patented his improved design and it was awarded the Grand Prize at the 1867 Paris World Exhibition.

How does a gas vehicle work

• Integrated gas canisters• High pressure (200 bar)• Pressure regulator→ valves→

cylinders• Fuel consumption measured

in m3 (or kg)

• The fuel injectors must be disabled when the engine is running on gas, although fuel must still flow to the injectors and then pass directly to the return fuel line to provide cooling.

Gas injection system of CNG

According to the poulton

• The bi-fuel engines of the spark ignition petrol engines is of all sizes can be converted to natural gas by the fitting of a gas carburetor / mixer, regulator, shut-off valves, control system and fuel storage tanks.

The converted CNG engines suffer from

• Power loss• encounter driveability

problems• Lower fuel efficiency• Methane gas not always

available

• In performance terms the converted bi-fuel engine will generally have a 15-20 percent maximum power reduction than that for the petrol version.

• A further disadvantage of methane is that it is a greenhouse gas with a warming forcing factor many times

That of the principal greenhouse gas, CO2, gas leakage or vehicular emission, will have an impact on the overall greenhouse gas(GHG) emissions.

Power curves on gasoline and natural gas

A example of that

• A 15-20 percent loss in thermal efficiency was reported in a dual-fuel heavy-duty truck demonstration in Canada, where natural gas provided 60 percent of the total fuel requirement during dual-fuel operation.

Application

• Production of electricity

• Trains

• Buses

• Tractors

• Lorries

• Maritime application

Gas as a fuel characteristics

Gas refueling

According to poulton there are two refueling modes with CNG :• The first is fast fill• The second is slow fill

• Fast fill

• Fast fill normally requires some buffer high pressure (25 MPa) storage at the refueling station although an alternative is to use a compressor sized to fill vehicles directly without intermediate (or cascade) storage.

A typical medium-sizedrefueling station with a compressor output around of 300 m3/hour would

be capable of servicing 30 buses or 300 cars over a 12-hour period.

Slow fill

• The slow fill is where one or more vehicles are connected directly to a low pressure supply via a compressor over relatively long time periods without the high pressure buffer storage facility.• For many fleet operations therefueling installation will be located at the fleet garage with trickle fill dispensers located adjacent to the vehicle parking spaces.

Conclusion

• CNG is attractive for five reasons:

1)It is the only fuel cheaper than gasoline or diesel. 2)It has inherently lower air pollution emissions. 3)It has lower greenhouse gas emissions.

4) Its use extends petroleum supplies5)there are large quantities of the fuel available in the world.• There are several major

problems needed to be solved when using natural gas engines:

1) There is the set point for the best compromise between emissions and fuel economy is not clear.2)The optimum air–fuel ratiochanges with both operating conditions and fuelproperties.

”No single issue is as fundamental to our future as energy”

The End