Transportation
description
Transcript of Transportation
Transportation
Alicia Kettler, Dana Sweatlock, Elizabeth De Smet
History
• 3 types of engines– Gas– Diesel
• Daimler, Benz– Steam
• Patented by Savery• Improved by Watt
Gas, Diesel, & Steam
• Gas– http://auto.howstuffworks.com/engine1.htm
• Diesel• http://www.howstuffworks.com/diesel1.htm
• Steam– http://www.howstuffworks.com/steam1.htm
Efficiency
• The efficiency of engines whether gasoline, diesel, or steam are important factors in pollution and resource consumption
Combustion
• There are two forms of combustion in engines– Internal
• Where fuel is burned inside the engine– External
• Where fuel is burned outside the engine
• Steam engines utilize external combustion• Diesel and gasoline engines use internal
combustion
Steam Engines• Steam engines are
only about 1-3% efficient
• This is due to a loss of heat to the atmosphere
• A condenser can be added with the potential of higher efficiency but the difference is small
http://sitemanager.ncl.ac.uk/images/projects/swan_2774.jpg
Gasoline Engines
• Only 15% of the energy from fuel goes to moving the car
• That does not take into consideration that there is inefficiency in gas production
• Overall the engine is about 25% efficient
http://www.fueleconomy.gov/feg/tech/energy.gif
Diesel Engines
• About 30-35% efficient concerning the energy that goes to movement
http://www.hydrogen-fc.com/wp-content/uploads/2007/01/efficiency_comparison.jpg
New Technologies
• In recent years, there have been many new advancements in transportation technologies. Some of these advancements include:– Natural Gas Vehicles– Electric Vehicles– Hydrogen Fuel Cell Vehicles
Natural Gas Vehicles (NGV’s)
• 110,000 NGV’s on the road today – 11 million worldwide– 1,100 fueling stations in the US – half open to
public• At the pump, natural gas costs about half as much as a
gallon of gasoline.• Natural Gas is sold in gasoline gallon equivalents (GGE).
A GGE has the same energy content as a gallon of unleaded gasoline without ethanol (125,000 Btu)
http://www.ngvc.org/about_ngv/index.html
Natural Gas Vehicles Cont…
• Benefits– Less dependent on foreign oil
• 98% of natural gas used is produced in North America– Reduced emissions
• Carbon monoxide by 70-90%• Non-methane organic gas by 50-75%• Nitrogen oxides by 75-95%• Carbon dioxide by 20-30%
– Natural gas has less carbon than any other fossil fuel
http://www.ngvc.org/about_ngv/index.html
Natural Gas Vehicles Cont…• Benefits
– Safety• Natural gas dissipates into the atmosphere in the event
of an accident– No pools on the ground, like gasoline, that could create a fire
hazard• Fuel storage cylinders for natural gas are stronger than
those used for gasoline.• Natural gas has a higher ignition temperature than
gasoline and a narrow range of flammability. • Natural gas is not toxic or corrosive – will not
contaminate ground water
http://www.ngvc.org/about_ngv/index.html
Natural Gas Vehicles Cont…
• Target audience– Lack of infrastructure – Fleets
• Fleets usually refuel in a central location and don’t need a widespread infrastructure
• Many fleets are already beginning to use NGV’s– Taxi cabs– Transit buses– School buses– Delivery vehicles– Street sweepers
http://www.ngvc.org/about_ngv/index.html
Electric Vehicles
• Electric vehicles are propelled by an electric motor powered by rechargeable battery pack.
• There are several advantages over internal combustion engines, as well as several significant disadvantages
http://www.fueleconomy.gov/feg/evtch.shtml
Electric Vehicles cont…• Advantages
– Energy efficient- 75% of chemical energy from battery goes to power the wheels
• Internal combustion engines only convert about 20%– Environmentally friendly – no tailpipe pollution
• BUT not emission free if a fossil fuel power plant generates the electricity to charge the vehicle
– Performance benefits – quiet smooth operation
http://www.fueleconomy.gov/feg/evtch.shtml
Electric Vehicles cont…• Disadvantages
– Driving Range – EV’s can only go 100-200 miles before needing to be recharged
• Gasoline vehicles on average can go about 300 miles– Recharge time – full charge- 4-8 hours, “quick
charge” of 80% battery- 30 minutes.– Battery cost – expensive and need to be replaced
more often than a battery in a gasoline car– Bulk & Weight – battery packs are heavy and large
http://www.fueleconomy.gov/feg/evtch.shtml
Electric Vehicles Coming The Nissan Leaf The Mini Cooper Electric
Ford Focus Electric
Hydrogen
• Charged plates conduct hydrogen– The electrons released create a current– http://inventors.about.com/od/sstartinventions/ss
/Physics_Illustr_2.htm• Water is released as a byproduct
Hydrogen Fuel Cell Efficiency
• A fuel cell’s efficiency is dependant on the fuel that it is charged with
• A cell powered by pure hydrogen can be 80% efficient
http://i36.tinypic.com/n3nqz7.jpg
Conversion
• The energy taken from the hydrogen would be converted to electrical energy and then to mechanical work
• The electric motor and inverter perform this process
• This step is about 80% efficient making the cell only about 64% efficient under ideal circumstances
Fuel
• If the fuel does not come from pure hydrogen the vehicle requires the use of a transformer, which will turn hydrocarbon and alcohol fuels into hydrogen
• The heat given off in this process lowers the efficiency of the system
Efficiency in Practice• Fuel cell vehicles
are only about 40% efficient
• The losses that come from the production (“power-plant-to-wheel”) lowers the efficiency to 22% for gaseous hydrogen and 17% for liquefied hydrogen
http://www.blogcdn.com/green.autoblog.com/media/2006/11/slides-for-sam.jpg
Benefits of Fuel Cells
• Fewer emissions/pollutants– Tailpipe emits only heat and water– Only pollutants and greenhouse gasses that are
emitted come from the fossil fuels used to produce hydrogen
• Reduce oil dependence– Hydrogen can be derived from domestic sources
• Fuel cells can store enough hydrogen to travel about as far as a gasoline engine.
http://www.fueleconomy.gov/feg/fcv_benefits.shtml
Challenges of Fuel Cells• Onboard Hydrogen Storage – systems are large, heavy, and
expensive• Vehicle cost- too expensive to compete with hybrids and
gasoline/diesel vehicles• Fuel Cell durability/reliability- not as durable as internal
combustion engines• Lack of infrastructure
– There is currently no infrastructure in place to deliver hydrogen to consumers. New facilities need to be made for producing, transporting, and dispensing hydrogen to consumers
• Safety/Public Acceptance – public does not now how to handle hydrogen – new fuel storage– Fuel cell technology needs to be embraced by consumers before it is
economically viable.
http://www.fueleconomy.gov/feg/fcv_benefits.shtml
The Future of Hydrogen Fuel Cells
• Many car manufacturers are currently working on hydrogen fuel cell vehicles– BMW – CleanEnergy Education Program– Chrystler – ecoVoyager concept vehicle– Ford – fuel cell vehicles– GM – Chevy Equinox fuel cell vehicle– Honda – FCX Clarity fuel cell vehicle– Nissan – X-Trail fuel cell vehicle
Chevy Equinox Fuel Cell
Honda FCX Fuel Cell
BMW CleanEnergy Fuel Cell
Nissan X-Trail Fuel Cell