Transportation

Document Sample
Transportation Powered By Docstoc
					EGEE 102 – Energy Conservation
And Environmental Protection


Transportation
    Automobiles in the US
    (1994)
•   156 Million Vehicles
•   11,400 miles average miles/y
•   578 gallons of gasoline
•   19.8 mpg
•   88.3 billion gal of gasoline
•   1.2 billion gal of Diesel

                  EGEE 102         2
 How Cars Work?
• Almost all cars currently use what is called a
  four-stroke combustion cycle to convert
  gasoline into motion. The four-stroke
  approach is also known as the Otto cycle, in
  honor of Nikolaus Otto, who invented it in
  1867. The four strokes are
• The intake stroke.
• The compression stroke.
• The combustion stroke
• The exhaust stroke
                     EGEE 102                      3
Best website for
information


  http://www.howstuffworks.com/engine.htm




                  EGEE 102                  4
SI Engine Operation




         EGEE 102     5
    Parts of an Engine

•   Cylinder
•   Spark Plug
•   Valves
•   Piston
•   Piston Rings
•   Cooling system
•   Crankshaft
                 EGEE 102   6
Cylinder Arrangement
V-6 Engine




         EGEE 102      7
Cylinder Arrangement
Inline Arrangement




         EGEE 102      8
Cylinder Arrangement
Flat Cylinder




         EGEE 102      9
The Camshaft




        EGEE 102   10
Engine Cooling System




         EGEE 102       11
 Compression Ratio
The difference between the maximum and minimum is
  called the displacement and is measured in liters or
  CCs (Cubic Centimeters, where 1,000 cubic
  centimeters equals a liter). So if you have a 4-
  cylinder engine and each cylinder displaces half a
  liter, then the entire engine is a "2.0 liter engine." If
  each cylinder displaces half a liter and there are six
  cylinders arranged in a V configuration, you have a
  "3.0 liter V-6."


                          EGEE 102                        12
 Efficiency
• When the United States recognized the hazards of its
  dependency on foreign oil supplies in the aftermath of
  the first oil embargo in 1973, passenger automobile
  fuel economy averaged only 14 miles per gallon
  (mpg).
• Congress established Corporate Average Fuel
  Economy (CAFE) standards in 1975 for each
  automaker, with domestically produced and imported
  automobiles counted as separate fleets.The uniform
  CAFE standard for automobiles began at 18 mpg
  with the 1978 model year, increasing to 27.5 mpg by
  1985
                        EGEE 102                      13
Energy Intensity of
Passenger Transport




         EGEE 102     14
Energy Intensity of
Freight Transport
(Btu/ton-miles)




                                EGEE 102                                     15
 Source: http://www.eia.doe.gov/emeu/efficiency/eefig_ch5.htm#Figure%205.5
 Efficiency of a IC Engne
• As the compression ratio increases efficiency
  increases
• As the compression ratio increases, fuel
  quality (Octane number) is important
• Higher compression ratios produce more
  power, up to a point. The more you compress
  the air/fuel mixture, however, the more likely it
  is to spontaneously burst into flame (before
  the spark plug ignites it). Higher octane
  gasoline prevents this sort of early
  combustion           EGEE 102                 16
Gasoline: Octane
Number
1. Octane has an octane rating of 100
2. Heptane has an octane rating of 0

Gasoline is compared in a test engine
  with a mixture of heptane and “octane.”

The higher the “octane” number the less
  likely to knock.
                       EGEE 102                     17
For More info: http://www.howstuffworks.com/question90.htm
 Octane Number

Higher octane numbers are obtained by
  adding:

1. Branched chain hydrocarbons

2. Aromatics (now being reduced)

3. Antiknock agents
                  EGEE 102              18
Tubocharger




        EGEE 102   19
Where the turbocharger is
located in the car
                • Power is determined
                    by the amount of air
                    and fuel that it can
                    burn.
                • The typical boost
                    provided by a
                    turbocharger is 6 to
                    8 pounds per square
                    inch (PSI).
                •
           EGEE 102 Increased restriction20
                    in the exhaust
 Cars and Environment

• See hand out




                 EGEE 102   21
 Automobile Emissions
• Hydrocarbons (Paraffins, Olefins,
  Naphthenes, Aromatics)
• Nitrogen Oxides (NO, NOx, NO2)
• Carbon Dioxide (CO2)
• Carbon Monoxide (CO)
• Particulates (any material collected
  on a filtering medium after exhaust
  dilution)
• Air Toxics (???)EGEE 102             22
Average Passenger Car
Emissions
 Pollutant          Emission Rate
                    (g/mile)
 Hydrocarbons       2.8
 Carbon          20.9
 Monoxide
 Nitrogen Oxides 1.39
 CO2                0.916 lb
 Gasoline           0.0465 gal
                EGEE 102            23
 Personal Auto Emissions

• Calculate the annual emissions (lbs)
  by your car based on the average
  annual mileage and the kind of car
  you you (mpg)?




                EGEE 102             24
 Effect of Carpooling

• Average commute is 20 miles round
  trip.
• 1,000 people participate in the
  carpool program.
• Calculate the personal monetary
  savings annually and the reduction
  of emissions (lbs) based on the
  emissions per mile
                EGEE 102           25
Sources of Emissions

  Source                Pollutant %
                CO HC       NOx Particles
  Exhaust       100 62      100 90
  Crankcase         20           10
  emission
  Fuel Tank         9
  Evaporation
  Carburetor        9
  evaporation


                   EGEE 102                 26
 Processes by Which
 Gasoline Compounds
 Escape Burning
• Gasoline vapor-air mixture
  compressed into the combustion
  chamber crevice volumes
• Gasoline compounds absorbed in oil
  layers on the cylinder liner
• Gasoline absorbed by, and/or
  contained within, deposits on the
  cylinder head and piston crown.
               EGEE 102            27
Parameters that
Influence Emissions
from Gasoline Engines
• Carburetion and Fuel Injection
• Spark timing
• Surface to volume ratio, valve timing
  and the use of exhaust gas
  recirculation


                EGEE 102             28
 Environmental Problems
• The pollution comes from two sources. The
  first is the combustion of the oil. The oil
  makes all two-stroke engines smoky to some
  extent, and a badly worn two-stroke engine
  can emit huge clouds of oily smoke.
• Each time a new charge of air/fuel is loaded
  into the combustion chamber, part of it leaks
  out through the exhaust port. That's why you
  see a sheen of oil around any two-stroke boat
  motor.
                    EGEE 102                 29
Catalytic Converters




         EGEE 102      30
Pollution Reduction
               • A three-way catalytic
                 converter - Both types
                 consist of a ceramic
                 structure coated with
                 a metal catalyst,
                 usually platinum,
                 rhodium and/or
                 palladium. two
                 separate catalysts.



         EGEE 102                   31
Honeycomb Structure




        EGEE 102      32
 Catalyst Function
• The reduction            • The oxidation catalyst
  catalyst is the first      is the second stage of
                             the catalytic converter.
  stage of the catalytic
                             It reduces the unburned
  converter. It uses         hydrocarbons and
  platinum and               carbon monoxide by
  rhodium to help            burning (oxidizing) them
  reduce the NOx             over a platinum and
  emissions.                 palladium catalyst.


                      EGEE 102                     33
 What You Can do to
 Save the Environment
• See the Handout (Your Car and
  Clean Air)
• Avoid Unnecessary Driving
• Maintain your car properly
• Drive your car wisely



               EGEE 102           34
    How to Help an Engine
    Produce More Power
•   Increase displacement
•   Increase the compression ratio
•   Stuff more into each cylinder
•   Cool the incoming air
•   Let air come in more easily
•   Let exhaust exit more easily
•   Make everything lighter
•   Inject the fuel
                    EGEE 102         35
 Hybrid Technology
 Efficiency
• Recover energy and store it in the
  battery
• Sometimes shut off the engine
• Use advanced aerodynamics to
  reduce drag
• Use low-rolling resistance tires
• Use lightweight materials
                 EGEE 102              36
   Hybrid Cars Available
        http://www.eren.doe.gov/EE/transportation.html




                            Honda Insight
http://www.honda2001.com/insight/homepage.html



                 Toyota Prius
                          EGEE 102                       37
 HEVs
• The HEV is able to operate
  approximately two times more
  efficiently than conventional vehicles.
  Honda's Insight can go 700 miles on a
  single tank of gas. The Toyota Prius can
  go about 500 miles. For the driver,
  hybrids offer similar or better
  performance than conventional
  vehicles. More important, because such
  performance is available now, hybrids
  are a practical way for consumers to
  chose a cleaner drive today.
                    EGEE 102              38
Cars of the Future
                          • Hybrid cars
                                • combines two or
                                  more sources of
                                  power.
                          • Fuel Cells



 http://www.eren.doe.gov/EE/transportation.html


                     EGEE 102                       39
    http://www.ott.doe.gov/pdfs/fuelcell_basics.pdf
 Fuel Cells
• Based on an electrochemical reaction
  that combines hydrogen with ambient
  air
• Pure hydrogen or any fossil fuel that
  has been "reformed" can be used to
  produce a hydrogen-rich gas
• Fuel cell's emission is mostly water
  vapor
• Energy conversion efficiencies up to
  50% are demonstrated
• ..\..\..\Desktop\Ami_320x240.ram
                    EGEE 102                          40
    Alternative Fuels

•   Methanol
•   Ethanol
•   CNG
•   Oxygenated Fuels
•   Reformulated Fuels

      More information on Clean Fuels:
      http://www.epa.gov/otaq/consumer/06-clean.pdf
                        EGEE 102                      41
 Two Stroke Engines

• Lawn and garden equipment (chain
  saws, leaf blowers, trimmers)
• Dirt bikes
• Mopeds
• Jet skis
• Small outboard motors
• Radio-controlled model planes
                EGEE 102             42
2 Stroke Engine
              • Two-stroke engines do
                not have valves, which
                simplifies their
                construction.
              • Two-stroke engines fire
                once every revolution
                (four-stroke engines fire
                once every other
                revolution) -- this gives
                two-stroke engines a
                significant power boost.

         EGEE 102                      43
Two Strokes




        EGEE 102   44
 Disadvantages of Two
 Stroke Engines
• Two-stroke engines don't last nearly as long as four-
  stroke engines. The lack of a dedicated lubrication
  system means that the parts of a two-stroke engine
  wear a lot faster.
• Two-stroke oil is expensive, and you need about 4
  ounces of it per gallon of gas. You would burn about
  a gallon of oil every 1,000 miles if you used a two-
  stroke engine in a car.
• Two-stroke engines do not use fuel efficiently, so you
  would get fewer miles per gallon.
• Two-stroke engines produce a lot of pollution. So
  much, in fact, that it is likely that you won't see them
  around too much longer. 102
                           EGEE                            45