11.1 11.2 Spark Ignition Engines11.3 Compressed Ignition Engines11.4 Advanced technology

11.1 11.1.1

11.1.2

11.1.3 1014% 9220% 1%1.021.94

2

135.84

178.29

321.12

361.95

408.07

464.39

511.32

551.36

606.11

691.74

817.58

914.95

1040

1100.08

1219

1313

/104

12city(ENG)

12

//

Standard Buses per 104 personsRoad area per capitaBus number (standard)Passenger transport (106 persons)

1997199319971993199719931997199319971993

1Shanghai8.6888.93535.213.24.93.21623785212636.795626.87

2Beijing6.1095.74819.2145.84.8854848903373.892862.68

3Tianjin4.6984.586.467.77.128962193536.47397.19

4Wuhan3.5643.34612.98.843.643551971943.491250.57

5Shenyang3.493.7247.57.58.24.723592406625.05536.52

6Guangzhou3.2673.03614.896.84.5461123381073.56663.72

7Chongqing2.882.3448.58.94.6424792090502.49752.96

8Ha'erbin2.5672.57612.17.33.75.331391344542.74612.13

9Nanjing2.3482.1749.7117.24.823602412499.32500.17

10Xi'an2.2552.067.38.15.15.51418871299.35355.04

11Chengdu2.0951.8358.18.15.54.216181408293.37288.2

12Changchun2.0321.75710.76.84.9522491031340.66309.57

43.99342.115152.4108.768.456.7522693147511667.1814155.62

3.6663.5110.79.15.74.74355.82662.9972.271179.64

194.699165.5018.667.86.51685668860627348.8827258.91

Shanghai

Beijing

Tianjin

Wuhan

Shenyang

Guangzhou

Chongqing

Ha'erbin

Nanjing

Xi'an

Chengdu

Changchun

12city(ENG)

00000

00000

00000

00000

00000

00000

00000

00000

00000

00000

00000

00000

Standard Buses per 104 persons

#REF!

#REF!

Passenger transport (106 persons)

12city(CHN)

00

00

00

00

00

00

00

00

00

00

00

00

1997

1993

/

7city

00

00

00

00

00

00

00

00

00

00

00

00

1997

1993

/

lead

00

00

00

00

00

00

00

00

00

00

00

00

1997

1993

urbanization

00

00

00

00

00

00

00

00

00

00

00

00

1997

1993

road-density

00

00

00

00

00

00

00

00

00

00

00

00

1997

1993

Buses/10000 persons

Ratio of buses possession

vehicle-pop+increa

00

00

00

00

00

00

00

00

00

00

00

00

1997

1993

Square meter/person

Road area per person

Sheet1

00

00

00

00

00

00

00

00

00

00

00

00

1997

1993

Number of standard buses

Public buses

00

00

00

00

00

00

00

00

00

00

00

00

1997

1993

Million persons

Passenger transport by busses

12

//

1997199319971993199719931997199319971993

18.6888.93535.213.24.93.21623785212636.795626.87

26.1095.74819.2145.84.8854848903373.892862.68

34.6984.586.467.77.128962193536.47397.19

43.5643.34612.98.843.643551971943.491250.57

53.493.7247.57.58.24.723592406625.05536.52

63.2673.03614.896.84.5461123381073.56663.72

72.882.3448.58.94.6424792090502.49752.96

82.5672.57612.17.33.75.331391344542.74612.13

92.3482.1749.7117.24.823602412499.32500.17

102.2552.067.38.15.15.51418871299.35355.04

112.0951.8358.18.15.54.216181408293.37288.2

122.0321.75710.76.84.9522491031340.66309.57

43.99342.115152.4108.768.456.7522693147511667.1814155.62

3.6663.5110.79.15.74.74355.82662.9972.271179.64

194.699165.5018.667.86.51685668860627348.8827258.91

Shanghai

Beijing

Tianjin

Wuhan

Shenyang

Guangzhou

Chongqing

Ha'erbin

Nanjing

Xi'an

Chengdu

Changchun

8.68835.24.9162372636.79

6.10919.25.885483373.89

4.6986.47.72896536.47

3.56412.944355943.49

3.497.58.22359625.05

3.26714.86.846111073.56

2.888.54.62479502.49

2.56712.13.73139542.74

2.3489.77.22360499.32

2.2557.35.11418299.35

2.0958.15.51618293.37

2.03210.74.92249340.66

Standard Buses per 104 persons

#REF!

#REF!

Passenger transport (106 persons)

35.213.2

19.214

6.46

12.98.8

7.57.5

14.89

8.58.9

12.17.3

9.711

7.38.1

8.18.1

10.76.8

1997

1993

/

4.93.2

5.84.8

7.77.1

43.6

8.24.7

6.84.5

4.64

3.75.3

7.24.8

5.15.5

5.54.2

4.95

1997

1993

/

162378521

85484890

28962193

43551971

23592406

46112338

24792090

31391344

23602412

1418871

16181408

22491031

1997

1993

2636.795626.87

3373.892862.68

536.47397.19

943.491250.57

625.05536.52

1073.56663.72

502.49752.96

542.74612.13

499.32500.17

299.35355.04

293.37288.2

340.66309.57

1997

1993

35.213.2

19.214

6.46

12.98.8

7.57.5

14.89

8.58.9

12.17.3

9.711

7.38.1

8.18.1

10.76.8

1997

1993

/

4.93.2

5.84.8

7.77.1

43.6

8.24.7

6.84.5

4.64

3.75.3

7.24.8

5.15.5

5.54.2

4.95

1997

1993

/

162378521

85484890

28962193

43551971

23592406

46112338

24792090

31391344

23602412

1418871

16181408

22491031

1997

1993

2636.795626.87

3373.892862.68

536.47397.19

943.491250.57

625.05536.52

1073.56663.72

502.49752.96

542.74612.13

499.32500.17

299.35355.04

293.37288.2

340.66309.57

1997

1993

1997646.2860250392.38379.64259.7100.34

1997km2488412.27170266.75299.47185.398

1997%33.4317.825.827.534.3539.226.9

1997%.

km549.498026.584.4

km4221.318.48

km1114.8

km/h13-19

11.1.4

HC

7.24

9.64

13.17

CO

72.37

45.19

195.55

NOX

1.84

2.84

4.5

HC

1.86

2.24

6.74

CO

14.03

17.7

72.97

NOX

1.02

1.14

3.29

/104t

/%

/%

CO

1995

107.5

76.8

76.5

86.3

1998

129.0

82.7

84.1

89.5

NOx

1995

9.38

40.2

68.4

72

1998

11.5

42.9

72.8

73.6

11.1.5 HC 20%CONOXPb HC 60%HC15%

11.2 Spark Ignition Engines11.2.1 Theoretical Combustion

=6~10=16~24=(Vc+Vd)/VcEngine Cylinder

Actual CombustionLeadHydrocarbonsCarbon MonoxideOxides of NitrogenCarbon DioxideParticulatesOther pollutantsWater Vapor

(C8H17): 14.7CO:HCStoichiometry

HC:

NOx: Thermal NOPrompt NOFuel NO

Other Emissions

1: ?

?

?

?

-------------,

New Cars Are Cleaner and More Efficient

Conventional carburetor car

(IM240)

_1003611110.doc

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240

mph

_1119797880.doc

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220

240

m/s

1. , CO, HC, : CO: 1.0%6%; HC: 4003000ppm NOx: 10100ppm

2. , NOx, : NOx: 10004000ppm CO: 0.53.0%; HC: 200600ppm , : 0.005g/m3

2: ?

? (, )

: (0.013g/L), (1200ppm50ppm) (EGR): 20%, NOx60%, 3%

: / ; ;

: , (, --)

(EGR)

3: CO, HC, NOx: (TWC)

+, Pt, Rd, Pd80000160000km, ! (TWC)

(crankcase)

Evaporative emission control

Clean Air Strategy DevelopedComplete Lead Phase Out by 2000Introduce Euro 1(1992 Vintage,Catalyst Based) Standards for Cars & Lt.Trucks in 2000 (Beijing,Shanghai 1999)Heavy Truck Standard,Euro 1,also in 2001(2000 in Beijing)I/M Pilot Being Developed in Shanghai

3: ?

?

?

-------------

11.3 Compressed Ignition Engines,

, , 3050%, , , 3,

Formation path of Soot

Pollutants and Air-fuel ratio

1. CO, 0.1%

2. , HC, 400ppm NOx, 3070ppm 3. , NOx, : NOx: 8002500ppm HC: 90200ppm

4. , 0.30g/m3

Inter-coolerTurbo-charge and Emission

Oxidation catalyst

Particulate Trap

11.4 Advanced Technology

(OBD)

PMNOx

4: ?

?

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----------,

Thus, enforcement is the most critical component of an I/M program. It is more important than the test you use, more important than quality control, more important the standards. All of the technical and policy questions are irrelevant if you cannot insure that all of the subject vehicles show up to get tested when they are supposed to. While this may seem easy enough to do, in reality has proven very difficult. Once you get the cars to show up, you need enforcement to make sure that the tests are conducted honestly, the repairs are effective, and the retests are also done honestly. Corruption can easily eliminate the benefits of the I/M program.Finally, on old technology vehicles especially, you need a way to prevent readjustment - usually enrichment of the air-fuel mixture - after the retest. If vehicles are only clean for a day, then air quality benefits will not be realized.Under ideal, theoretical conditions, combustion would look like this. Ignition of a combination of fuel and oxygen would yield energy, with carbon dioxide and water vapor as side products. The goal of mobile source pollution control has been to force technology and the users of combustion equipment to come closer to this ideal. This theoretical combustion equation does not happen in the real world. In reality, many things are going on and many factors are influencing the process.Besides tailpipe emissions, motor vehicles also pollute in other ways and some of these sources can be significant. Evaporative emissions and refueling losses are major sources of raw, unburned hydrocarbons released into the atmosphere. We estimate that in the U.S. - given very tight controls on tailpipe emissions - evaporative emissions contribute as much as half the excess emissions from vehicles! Actual combustion is much different from theoretical combustion. Instead of oxygen, we are dealing with air - a mixture of oxygen, nitrogen, and other gases and particles. The fuel is not a pure, simple compound but rather a complex mixture of hydrocarbons, sulfur, lead, and other substances that have a significant impact on emissions from vehicles. Because we need the energy produced by combustion to do useful work - in this case push a piston - we are combust gasoline under less than ideal conditions inside a cylinder. So, what comes out the tailpipe is not simply water and CO2 but rather a complex mix of pollutants that result from these less than ideal operating conditions.Another way to look at ideal combustion is to consider the ideal air fuel mixture. At an air-fuel mixture of 14.5:1, stoichiometry, the operation of the combustion engine is optimized - taking into consideration the full range of factors we are trying to control. Note, however, that at 14.5:1, the HC and CO emissions are reduced by the NO emissions increase dramatically. This fundamental trade off in emission control makes reducing pollution from combustion engines very difficult.Another way to look at ideal combustion is to consider the ideal air fuel mixture. At an air-fuel mixture of 14.5:1, stoichiometry, the operation of the combustion engine is optimized - taking into consideration the full range of factors we are trying to control. Note, however, that at 14.5:1, the HC and CO emissions are reduced by the NO emissions increase dramatically. This fundamental trade off in emission control makes reducing pollution from combustion engines very difficult.Another way to look at ideal combustion is to consider the ideal air fuel mixture. At an air-fuel mixture of 14.5:1, stoichiometry, the operation of the combustion engine is optimized - taking into consideration the full range of factors we are trying to control. Note, however, that at 14.5:1, the HC and CO emissions are reduced by the NO emissions increase dramatically. This fundamental trade off in emission control makes reducing pollution from combustion engines very difficult.Besides tailpipe emissions, motor vehicles also pollute in other ways and some of these sources can be significant. Evaporative emissions and refueling losses are major sources of raw, unburned hydrocarbons released into the atmosphere. We estimate that in the U.S. - given very tight controls on tailpipe emissions - evaporative emissions contribute as much as half the excess emissions from vehicles! There is hope however, Since we started controlling emissions from motor vehicles back in the 1960s, we have seen a tremendous reduction in the emissions from motor vehicles while improving fuel economy at the same time. This benefit has come from new vehicle standards.Transient testing is the best general purpose tailpipe emission test that we have developed to date. New vehicle standards are a function of a transient loaded test so it stands to reason that such a test is going to be a good choice. By transient we mean two things: first, the speed at which the vehicle is operated during the course of the test varies. Second, the load the vehicle is subjected to varies as well. The other feature of transient tests that contributes to their effectiveness is time. Instead of being a snapshot, they measure emissions at different speeds and loads over the course of a significant amount of time. By comparison, other tailpipe emission test result are usually based on only 5-10 seconds of measurement (under steady state conditions). The remote sensing test is less than 1 second usually under unknown conditions.

This driving trace for the IM240 shows the speed/time relationship over the course of the test.New standards, however, will not solve all of your problems. The volume of new car sales and the rate of scrappage of old technology cars will have great influence on emission trends. Motor vehicle manufacturers have improved the quality and longevity of vehicles such that average age of vehicles in the U.S. fleet has been getting older slowly but surely. If conditions are such that old decrepit vehicles are kept in the fleet, their air quality impact will be huge. Another consideration relates to which standards and how they are enforced. Certification and compliance programs are expensive and complex to administer. The benefits of tight standards may be lost if the government infrastructure and resources do not exist to effectively manage a compliance program. Strong authority is required to permit enforcement - ultimately, denying a manufacturer the ability to sell a non-complying vehicle or engine. International manufacturers dont want to have to deal with different standards and certification programs in each country. Local manufacturers dont want to be left a competitive disadvantage to foreign competitors. Thus, allowing certificates from other countries may make it easier and cheaper to ensure and achieve compliance (by sharing information across national boundaries). One final thought, how will the cost of additional controls impact fleet turnover? In a rapidly growing economy, this may not be an important consideration. Nevertheless, a substantial increase in the cost of new vehicles as a result of new emission standards will affect demand. New standards, however, will not solve all of your problems. The volume of new car sales and the rate of scrappage of old technology cars will have great influence on emission trends. Motor vehicle manufacturers have improved the quality and longevity of vehicles such that average age of vehicles in the U.S. fleet has been getting older slowly but surely. If conditions are such that old decrepit vehicles are kept in the fleet, their air quality impact will be huge. Another consideration relates to which standards and how they are enforced. Certification and compliance programs are expensive and complex to administer. The benefits of tight standards may be lost if the government infrastructure and resources do not exist to effectively manage a compliance program. Strong authority is required to permit enforcement - ultimately, denying a manufacturer the ability to sell a non-complying vehicle or engine. International manufacturers dont want to have to deal with different standards and certification programs in each country. Local manufacturers dont want to be left a competitive disadvantage to foreign competitors. Thus, allowing certificates from other countries may make it easier and cheaper to ensure and achieve compliance (by sharing information across national boundaries). One final thought, how will the cost of additional controls impact fleet turnover? In a rapidly growing economy, this may not be an important consideration. Nevertheless, a substantial increase in the cost of new vehicles as a result of new emission standards will affect demand.