Path to High Efficiency Gasoline Engine

Home , Engine downsizing, Engine efficiency, Fuel efficiency

SI HCCI PPC

Prof. Bengt Johansson

Division of Combustion Engines Department of Energy Sciences Lund University 1 Scania diesel engine running on gasoline

Group 3, 1300 [rpm] 60 !

50 FR47333CVX 45 FR47334CVX FR47336CVX 40

30 Gross Indicated Efficiency [%] Efficiency Indicated Gross

20 0 2 4 6 8 10 12 14 Gross IMEP [bar]

ηi=57% = Isfc =147 g/kWh (@43 MJ/kg heating value)

2 Outline

• HCCI and fuel efficiency – 50% thermal efficiency • Partially premixed combustion, PPC – Background – Why gasoline is the best diesel engine fuel – 56% thermal efficiency in car size engine – 57% thermal efficiency in truck size engine – Why 55% thermal efficiency is better than 57% – How to reach 26 bar IMEP with US10 NOx, PM, HC and CO engine out 3 Outline

5 Energy flow in an IC engine

FuelMEP

Combustion efficiency QemisMEP

QhrMEP QhtMEP

Thermodynamic efficiency QlossMEP

QexhMEP Gross Indicated efficiency IMEPgross

Gas exchange efficiency PMEP

Net Indicated efficiency lMEPnet

Mechanical efficiency FMEP

Brake efficiency BMEP

= * * * η Brake η Combustion ηThermodynamic η GasExchange η Mechanical Thermodynamic efficiency Saab SVC variable compression ratio, VCR, HCCI, Rc=10:1-30:1; General Motors L850 “World engine”, HCCI, Rc=18:1, SI, Rc=18:1, SI, Rc=9.5:1 (std) Scania D12 Heavy duty diesel engine, HCCI, Rc=18:1; Fuel: US regular Gasoline

7 SAE2006-01-0205 All four efficiencies

8 Problem with HCCI: Too fast combustion

9 Phasing HCCI combustion late helps burn rate but

reduce ηC

10 Magnus Christensen Ph.D. thesis 2002 Outline

Spark Ignition (SI) Compression Ignition engine (Gasoline, (CI) engine (Diesel) Otto)

+ High efficiency Homogeneous Charge -Combustion control Compression Ignition + Ultra low NOx -Power density (HCCI)

Spark Assisted Partially premixed Compression Ignition combustion (PPC) (SACI) Diesel HCCI Gasoline HCCI + Injection controlled - Less emissions advantage Partially Premixed Combustion, PPC p y 6000 1200 CI HCCI PCCI 5000 PPC 1000

4000 800

3000 600 HC [ppm] NOx [ppm]

2000 400

1000 200

-180 -160 -140 -120 -100 -80 -60 -40 -20 SOI [ATDC] Def: region between truly homogeneous combustion, HCCI, and diffusion controlled combustion, diesel

13 PPC: Effect of EGR with diesel fuel

Load 8 bar IMEP Abs. Inlet Pressure 2.5 bar Engine Speed 1090 rpm Swirl Ratio 1.7 Compression Ratio 12.4:1 (Low)

Scania D12 single cylinder

14 DEER2005 1 2

3 4 Lund/Delphi/Volvo PPC Project Volvo D13 Multi-cylinder engine

NOx <0.3 g/kWh PM < 2 FSN using Swedish MK1 diesel fuel

Adapted from 16 SAE paper 2009-01-1127 Outline

Lic. Thesis by Henrik Nordgren 2005 and 18 presented at DEER2005 Outline

Injection SOI [TDC] Fuel MEP [bar] Percentage [%] 1 -64.00 10.88 41.28 2 -29.20 7.74 29.36 3 0.80 7.74 29.36

150

Cyl Pressure [bar] Inj Signal [a.u.] RoHR [J/CAD]

100

Load & CA50 N 2000 [rpm] Noise Load IMEPg 13.38 [bar] 50 Pin 2.57 [bar] Tin 354 [K] EGR 39 [%] 0 lambda 1.75 [-] -8020 -60 -40 -20 0 20 40 CAD [TDC] Efficiencies & Emissions

! D60 project goal 60 40 0.46 % 58 35 56 30 54

52 25 4598 ppm 50 20

48 Emissions 13 ppm Efficiency [%] 91 % 15 46 10 44 Below 42 5 Detectable Level 40 0 Indicated Gross Thermal Combustion/2 NOx*100 [g/kWh] CO [g/kWh] HC [g/kWh] Soot [FSN]

dPmax 7.20 [bar/CAD] CA5 3.40 [TDC] ID -1.00 [CAD] CA50 11.35 [TDC] CA90-10 13.00 [CAD] 21 Burn rate and ηT

Optimum Thermodynamic efficiency

150

Cyl Pressure [bar] Inj Signal [a.u.] Low effective RoHR [J/CAD] High heat expansion 100 losses ratio

0 -80 -60 -40 -20 0 20 40 CAD [TDC]

Premixedness 22 Outline

Bosch Common Rail

Prailmax 1600 [bar] Orifices 8 [-] Orifice Diameter 0.18 [mm] Umbrella Angle 120 [deg]

Engine / Dyno Spec BMEPmax 15 [bar] Vd 1951 [cm3] Swirl ratio 2.9 [-]

Fuel: Gasoline or Ethanol

24 Two Test Series: High & Low Compression Ratio

rc: 14.3:1 rc: 17.1:1

Low Compression Ratio PPC High Compression Ratio PPC

25 Injection Strategy

It consists of two injections. The first Const. Load & CA50 one is placed @ -60 TDC to create a 1 homogeneous mixture while the second 0.8 around TDC. The stratification created 0.6

by the second injection triggers the [a.u.] combustion. The first injection must not 0.4 It must not react during the compression stroke, react during 0.2 this is achieved by using EGR. compression

0 -60 -50 -40 -30 -20 -10 0 10 CAD [TDC]

Fuel amount in the pilot is a function of: 1.rc 2.RON/MON 3.EGR 26 SAE 2009-01-0944 High Compression Ratio PPC

IMEP sweep @ 1300 [rpm] EGR ~ const throughout the sweep, 40-50 [%] λ~ const throughout the sweep, 1.5-1.6 [-] Tin = 308 [K]

Standard piston bowl, rc: 17:1

27 SAE 2009-01-2668 Running Conditions

2.5 350 2 60

Inlet Temperature 300 1.9 Exhaust Temperature 55 2.25 1.8 250 50 1.7 200 Inlet Pressure

2 [-] 1.6 45 [C]

Exhaust Pressure λ [bar]

150 EGR [%] 1.5 40 100 1.75 1.4 35 50 1.3

1.5 0 1.2 30 4 5 6 7 8 9 10 11 12 13 4 5 6 7 8 9 10 11 12 13 Gross IMEP [bar] Gross IMEP [bar]

28 Efficiencies

100

80 Combustion Efficiency 75 [%] Thermal Efficiency 70 Gas Exchange Efficiency Mechanical Efficiency 65

50 4 5 6 7 8 9 10 11 12 13 Gross IMEP [bar]

29 Efficiency

57%

60 Too much rate Too much heat transfer controlled combustion 55

45 [%]

Gross Ind. Efficiency 40 Net Ind. Efficiency Brake Efficiency

30 2 4 6 8 10 12 14 Gross IMEP [bar]

30 Emissions

0.5 5 Obsolete injection 0.45 Gross 4.5 Net system 0.4 Brake 4 EU VI Not well tuned EGR-λ 0.35 3.5 US 10 combination 0.3 3

0.25 2.5

NOx [g/kWh] 0.2 2 Smoke [FSN] Smoke 0.15 1.5

0.1 1

0.05 0.5

0 0 2 4 6 8 10 12 14 2 4 6 8 10 12 14 Gross IMEP [bar] Gross IMEP [bar]

5 18

4.5 16 Gross 4 Gross 14 Net 3.5 Net Brake Brake 12 EU VI 3 EU VI US 10 US 10 10 2.5 8

HC [g/kWh] 2 CO [g/kWh] 6 1.5

1 4

0.5 2

0 31 0 2 4 6 8 10 12 14 2 4 6 8 10 12 14 Gross IMEP [bar] Gross IMEP [bar] Outline

IMEP sweep @ 1300 [rpm] EGR ~ const throughout the sweep, 40-50 [%] λ~ const throughout the sweep, 1.5-1.6 [-] Tin = 308 [K]

Custom piston bowl, rc: 14.3:1

33 SAE 2010-01-0871 Efficiencies

100

80 Combustion Efficiency

[%] 75 Thermal Efficiency 70 Gas Exchange Efficiency Mechanical Efficiency 65

50 4 6 8 10 12 14 16 18 Gross IMEP [bar]

34 Emissions

0.6 2 1.8 λ Gross Better tuned EGR- 0.5 Net 1.6 combination Brake 1.4 0.4 EU VI US 10 1.2

0.3 1

NOx [g/kWh] 0.8 Smoke [FSN] Smoke 0.2 0.6

0.4 0.1 0.2

0 0 2 4 6 8 10 12 14 16 18 4 6 8 10 12 14 16 18 Gross IMEP [bar] Gross IMEP [bar]

1.5 10 Gross 9 Gross Net Net 1.2 Brake 8 Brake EU VI EU VI US 10 7 US 10 0.9 6

HC [g/kWh] 0.6 CO [g/kWh] 4

0.3 2

0 35 0 2 4 6 8 10 12 14 16 18 2 4 6 8 10 12 14 16 18 Gross IMEP [bar] Gross IMEP [bar] Emissions – different fuels

Ethanol 2.5 0.5 FR47330CVX 0.45 FR47331CVX Ethanol FR47333CVX FR47330CVX 0.4 FR47334CVX 2 FR47331CVX FR47335CVX FR47333CVX 0.35 FR47336CVX FR47334CVX 0.3 FR47338CVX 1.5 FR47335CVX FR47336CVX 0.25 FR47338CVX Soot [FSN]

NOx [g/kWh] 0.2 1

0.15

0.1 0.5

0.05

0 0 2 4 6 8 10 12 14 16 18 20 2 4 6 8 10 12 14 16 18 20 Gross IMEP [bar] Gross IMEP [bar]

12 10 Ethanol Ethanol FR47330CVX 9 FR47330CVX 10 FR47331CVX 8 FR47331CVX FR47333CVX FR47333CVX FR47334CVX 7 FR47334CVX 8 FR47335CVX FR47335CVX FR47336CVX 6 FR47336CVX 6 FR47338CVX 5 FR47338CVX

CO [g/kWh] HC [g/kWh] 4 4 3

2 2 1

0 36 0 2 4 6 8 10 12 14 16 18 20 2 4 6 8 10 12 14 16 18 20 Gross IMEP [bar] Gross IMEP [bar] Outline

XPI Common Rail Orifices 8 [-] Orifice Diameter 0.19 [mm] Umbrella Angle 148 [deg]

Engine / Dyno Spec BMEPmax 25 [bar] Vd 2124 [cm3] Swirl ratio 2.095 [-]

38 Standard piston bowl, rc: 17.3:1 Efficiency

50% brake efficiency seems viable!!!

45 η brake η net 40 [%] η gross 35

20 5 10 15 20 25 30 Gross IMEP [bar]

39 Efficiency

50% brake efficiency  maximization of all intermediate efficiencies

= ⋅ ⋅ ⋅ η Brake η Combustion ηThermodynamic η GasExchange η Mechanical

100

90 η combustion η gas exchange 80 η thermal η mechanical 70 [%]

40 5 10 15 40 20 25 30 Gross IMEP [bar] RoHR, Cylinder Pressure & Injection Signal

IMEPg: 26 [bar] IMEPg: 20 [bar] IMEPg: 16 [bar] lambda: 1.32 [-] Abs Pin: 3.64 [bar] lambda: 1.37 [-] Abs Pin: 3.21 [bar] lambda: 1.36 [-] Abs Pin: 2.35 [bar] 250 EGR: 47.98 [%] Abs Pex: 4.01 [bar] 250 EGR: 53.22 [%] Abs Pex: 3.48 [bar] 250 EGR: 46.69 [%] Abs Pex: 2.88 [bar] CA50: 13.9 [TDC] Tin: 293 [K] CA50: 9.27 [TDC] Tin: 293 [K] CA50: 7.6 [TDC] Tin: 292 [K] COV: 0.56 [%] Tex: 673 [K] COV: 0.7 [%] Tex: 606 [K] COV: 0.58 [%] Tex: 623 [K] 200 200 200 eta comb: 99.89 [%] eta comb: 99.89 [%] eta comb: 99.82 [%] NOx: 0.264 [g/kWh] NOx: 0.201 [g/kWh] NOx: 0.281 [g/kWh] 150 HC: 0.091 [g/kW] 150 HC: 0.082 [g/kW] 150 HC: 0.1 [g/kW] CO: 0.31 [g/kW] CO: 0.31 [g/kW] CO: 0.63 [g/kW] RoHR/3 [J/CAD] RoHR/3 [J/CAD] RoHR/3 [J/CAD] Soot: 0.26 [FSN] Cylinder Pressure [bar] Soot: 0.21 [FSN] Soot: 0.31 [FSN] 100 100 Cylinder Pressure [bar] 100 Cylinder Pressure [bar] Injection Current [a.u.] Injection Current [a.u.] Injection Current [a.u.] 50 50 50

0 0 0 -60 -40 -20 0 20 40 60 -60 -40 -20 0 20 40 60 -60 -40 -20 0 20 40 60 CAD [TDC] CAD [TDC] CAD [TDC]

IMEPg: 11 [bar] IMEPg: 5 [bar] lambda: 1.48 [-] Abs Pin: 1.76 [bar] lambda: 1.57 [-] Abs Pin: 1.07 [bar] 250 EGR: 46.41 [%] Abs Pex: 2.73 [bar] 250 EGR: 42.66 [%] Abs Pex: 1.15 [bar] CA50: 6.82 [TDC] Tin: 291 [K] CA50: 9.71 [TDC] Tin: 308 [K] COV: 1.2 [%] Tex: 612 [K] COV: 2.2 [%] Tex: 521 [K] 200 200 eta comb: 99.4 [%] eta comb: 94.16 [%] NOx: 0.317 [g/kWh] RoHR/3 [J/CAD] NOx: 0.108 [g/kWh] RoHR/3 [J/CAD] 150 HC: 0.22 [g/kW] Cylinder Pressure [bar] 150 HC: 2.7 [g/kW] Injection Current [a.u.] Cylinder Pressure [bar] CO: 2.6 [g/kW] CO: 23 [g/kW] Injection Current [a.u.] Soot: 0.05 [FSN] Soot: 0.0033 [FSN] 100 100

50 50

0 0 -60 -40 -20 0 20 40 60 -60 -40 -20 0 20 40 60 CAD [TDC] CAD [TDC] RoHR, Cylinder Pressure & Injection Signal

IMEPg: 5 [bar] lambda: 1.57 [-] Abs Pin: 1.07 [bar] 250 EGR: 42.66 [%] Abs Pex: 1.15 [bar] CA50: 9.71 [TDC] Tin: 308 [K] COV: 2.2 [%] Tex: 521 [K] 200 eta comb: 94.16 [%] NOx: 0.108 [g/kWh] RoHR/3 [J/CAD] 150 HC: 2.7 [g/kW] Cylinder Pressure [bar] CO: 23 [g/kW] Injection Current [a.u.] Soot: 0.0033 [FSN] 100

0 -60 -40 -20 0 20 40 60 CAD [TDC] RoHR, Cylinder Pressure & Injection Signal

IMEPg: 11 [bar] lambda: 1.48 [-] Abs Pin: 1.76 [bar] 250 EGR: 46.41 [%] Abs Pex: 2.73 [bar] CA50: 6.82 [TDC] Tin: 291 [K] COV: 1.2 [%] Tex: 612 [K] 200 eta comb: 99.4 [%] NOx: 0.317 [g/kWh] RoHR/3 [J/CAD] 150 HC: 0.22 [g/kW] Cylinder Pressure [bar] CO: 2.6 [g/kW] Injection Current [a.u.] Soot: 0.05 [FSN] 100

0 -60 -40 -20 0 20 40 60 CAD [TDC] RoHR, Cylinder Pressure & Injection Signal

IMEPg: 16 [bar] lambda: 1.36 [-] Abs Pin: 2.35 [bar] 250 EGR: 46.69 [%] Abs Pex: 2.88 [bar] CA50: 7.6 [TDC] Tin: 292 [K] COV: 0.58 [%] Tex: 623 [K] 200 eta comb: 99.82 [%] NOx: 0.281 [g/kWh] 150 HC: 0.1 [g/kW] CO: 0.63 [g/kW] Soot: 0.31 [FSN] RoHR/3 [J/CAD] 100 Cylinder Pressure [bar] Injection Current [a.u.] 50

0 -60 -40 -20 0 20 40 60 CAD [TDC] RoHR, Cylinder Pressure & Injection Signal

IMEPg: 20 [bar] lambda: 1.37 [-] Abs Pin: 3.21 [bar] 250 EGR: 53.22 [%] Abs Pex: 3.48 [bar] CA50: 9.27 [TDC] Tin: 293 [K] COV: 0.7 [%] Tex: 606 [K] 200 eta comb: 99.89 [%] NOx: 0.201 [g/kWh] 150 HC: 0.082 [g/kW] CO: 0.31 [g/kW] Soot: 0.21 [FSN] RoHR/3 [J/CAD] 100 Cylinder Pressure [bar] Injection Current [a.u.]

0 -60 -40 -20 0 20 40 60 CAD [TDC] RoHR, Cylinder Pressure & Injection Signal

IMEPg: 26 [bar] lambda: 1.32 [-] Abs Pin: 3.64 [bar] 250 EGR: 47.98 [%] Abs Pex: 4.01 [bar] CA50: 13.9 [TDC] Tin: 293 [K] COV: 0.56 [%] Tex: 673 [K] 200 eta comb: 99.89 [%] NOx: 0.264 [g/kWh] 150 HC: 0.091 [g/kW] CO: 0.31 [g/kW] RoHR/3 [J/CAD] Soot: 0.26 [FSN] 100 Cylinder Pressure [bar] Injection Current [a.u.]

0 -60 -40 -20 0 20 40 60 CAD [TDC] Combustion Noise & Stability

10 5

9 HD Engine Treshold 4.5 8 4

7 3.5 HD Engine Treshold 6 3

5 2.5

4 2 COV of IMEP [%] 3 1.5

2 1

1 0.5

Relative Maximum Pressure Rise [bar/CAD] Rate Pressure Relative Maximum 0 0 0 5 10 15 20 25 30 0 5 10 15 20 25 30 Gross IMEP [bar] Gross IMEP [bar]

47 Emissions

0.6 0.5

Brake NOx 0.45 0.5 US10 0.4 EU VI 0.35 0.4 0.3

0.3 0.25

Soot [FSN] 0.2

Brake NOx [g/kWh] NOx Brake 0.2 0.15

0.1 0.1 0.05

0 0 0 5 10 15 20 25 30 5 10 15 20 25 30 Gross IMEP [bar] Gross IMEP [bar]

2 25

1.8 Brake HC Brake CO 1.6 US 10 20 US 10 EU VI EU VI 1.4

1.2 15

0.8 10

Brake HCBrake [g/kWh] 0.6 [g/kWh] CO Brake

0.4 5

0.2

0 48 0 0 5 10 15 20 25 30 0 5 10 15 20 25 30 Gross IMEP [bar] Gross IMEP [bar] Summary

49 Brake Efficiency

58 56 D12 High rc, G. 80/75 D12 Low rc, G. 69/66 54 D13 Standard, G. 69/66 52 50 48 46 44 Brake Efficiency [%] 42 40 38 36 0 5 10 15 20 25 30 Gross IMEP [bar]

Brake efficiency in the range of 48-50% seems to be viable between 12.5 and 26 bar gross IMEP. 50 D13 Running on Diesel & Gasoline

52 D13 Gasoline 50 D13 Diesel 48

40 Brake Efficiency [%]

34 5 10 15 20 25 30 Gross IMEP [bar] D13 Diesel was calibrated by Scania and the calibration was done to meet EU V legislation. Average improvement of 16.6% points @ high load!!! 51 Brake Emissions

0.6 4.5 D12 High rc 0.55 D12 High rc 4 D12 Low rc 0.5 D12 Low rc D13 Standard 3.5 0.45 D13 Standard EU VI 0.4 US 10 3 0.35 2.5 0.3 2 0.25 Soot [FSN] 0.2 1.5 0.15 Brake Specific NOx [g/kWh] SpecificNOx Brake 1 0.1 0.5 0.05 0 0 0 5 10 15 20 25 30 0 5 10 15 20 25 30 Gross IMEP [bar] Gross IMEP [bar]

4 35 D12 High rc D12 High rc 3.5 D12 Low rc 30 D12 Low rc D13 Standard D13 Standard 3 EU VI EU VI US 10 25 US 10 2.5 20 2 15 1.5 10 Brake SpecificHC Brake [g/kWh]

1 Specific[g/kWh] CO Brake

0.5 5

0 52 0 0 5 10 15 20 25 30 0 5 10 15 20 25 30 Gross IMEP [bar] Gross IMEP [bar] Engine combustion - direction

+ Clean with 3-way Catalyst + High efficiency - Poor low & part load - Emissions of NOx efficiency and soot

Compression 1900-1995 Spark Ignition (SI) Ignition (CI) engine engine (Gasoline, (Diesel) Otto)

Homogeneous + High Efficiency 1995-2005 Charge Compression + Ultralow NOx & soot Ignition (HCCI) - Combustion control - Power density 2005-2010 Diesel PPC + Injection controlled + High Efficiency - Efficiency at high load + Low NOx & soot 2010- Gasoline PPC 53 The End

Thank you

54 Path to High Efficiency Gasoline Engine

SI HCCI PPC

Prof. Bengt Johansson

Division of Combustion Engines Department of Energy Sciences Lund University 55 Outline

• Partially premixed combustion, PPC – Summary of • 56% thermal efficiency in car size engine • 57% thermal efficiency in truck size engine • Why 55% thermal efficiency is better than 57% – Fuel effects in Scania D12 engine – How to reach 26 bar IMEP with US10 NOx, PM, HC and CO engine out, Scania D13 – Fuel effects in Scania D13 engine

56 Fuel Matrix

RON MON C H/C O/C LHV [MJ/kg] A/F stoich Group 1 FR47335CVX 99.0 96.9 7.04 2.28 0.00 44.30 15.10 FR47332CVX 97.7 87.5 6.61 2.06 0.07 39.70 13.44 FR47337CVX 96.5 86.1 7.53 1.53 0.00 42.10 14.03 Group 2 FR47338CVX 88.6 79.5 7.21 1.88 0.00 43.50 14.53 FR47330CVX 87.1 80.5 7.20 1.92 0.00 43.50 14.60 FR47331CVX 92.9 84.7 6.90 1.99 0.03 41.60 14.02 Group 3 FR47336CVX 70.3 65.9 7.10 2.08 0.00 43.80 14.83 FR47334CVX 69.4 66.1 7.11 1.98 0.00 43.80 14.68 FR47333CVX 80.0 75.0 7.16 1.97 0.00 43.70 14.65 Group 4 PRF20 20 20 7.2 2.28 0 44.51 15.07 MK1 n.a. 20 16 1.87 0 43.15 14.9

57 Results

58 Tested Load Area

Stable operational load vs. fuel type

10 IMEP gross [bar] gross IMEP

0 20 30 40 50 60 70 80 90 100 RON [-]

59 NOx - ηcomb Trade – Off Solution

100

98 G. ON 99/97 G. ON 98/88 97 G. ON 97/86 96 G. ON 93/85 G. ON 89/80 95 G. ON 87/81 G. ON 80/75 94 G. ON 70/66 93 G. ON 69/66

Combustion Efficiency [%] Efficiency Combustion PRF20 92

91 HC/CO F/A EQUIVALENCE RATIO EQUIVALENCE F/A 90 0 0.2 0.4 0.6 0.8 1 TEMPERATURE NOx [g/kWh] Adiabatic Flame Temperature 2400 λ=1 λ=1.1 2200 λ=1.2 λ=1.3 λ=1.4 2000 λ=1.5 λ=1.6 λ 1800 =1.7 It is possible to achieve λ=1.8 λ=2 low NOx and still keep 1600 λ=2.5

Temperature [K] λ=3 λ=3.5 high combustion 1400 λ=4 efficiency in the whole 1200 load range! 60 1000 30 35 40 45 50 55 60 65 70 EGR Ratio [%] Efficiency & Emissions

0.05 60 G. ON 99/97 0.045 59 G. ON 98/88 G. ON 99/97 G. ON 97/86 0.04 G. ON 98/88 58 G. ON 93/85 G. ON 97/86 G. ON 89/80 0.035 G. ON 93/85 57 G. ON 87/81 G. ON 89/80 0.03 56 G. ON 80/75 G. ON 87/81 G. ON 70/66 0.025 G. ON 80/75 55 G. ON 69/66 G. ON 70/66 PRF20 0.02 G. ON 69/66 54 [g/kWh] Soot D. CN 52 0.015 53 PRF20 EU VI

Gross Indicated Efficiency [%] Efficiency Indicated Gross 0.01 52 US10 0.005 51 0 50 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 0.2 0.4 0.6 0.8 1 Indicated NOx [g/kWh] NOx [g/kWh]

In certain operating range, some fuels are capable to comply EU VI & US10 legislations and still keep high efficiency without compromising the efficiency!

61 Soot Emissions

2.5 G. ON 99/97 G. ON 98/88 G. ON 97/86 2 G. ON 93/85 G. ON 89/80 G. ON 87/81 Diesel vs. Gasoline 1.5 G. ON 80/75 G. ON 70/66 Soot [FSN] G. ON 69/66 1 D. CN 52 PRF20 0.5

0 0 5 10 15 20 25 30 Gross IMEP [bar]

62 Higher Power Density

IMEPg: 20 & 25 [bar] 3

2.5

G. ON 99/97 2 G. ON 98/88 G. ON 97/86 G. ON 93/85 1.5 G. ON 89/80

Soot [FSN] G. ON 87/81 1 G. ON 80/75 G. ON 70/66 G. ON 69/66 0.5 D. CN 52 PRF20

0 1 1.1 1.2 1.3 1.4 1.5 λ [-] Low soot even @ λ 1.3  higher power density without producing smoke!

63 Acoustic Noise

G. ON 99/97 Motored Engine 15 G. ON 98/88 5 G. ON 97/86 Measured 4.5 13 G. ON 93/85 Normalized G. ON 89/80 G. ON 87/81 4 11 G. ON 80/75 G. ON 70/66 3.5 9 G. ON 69/66 D. CN 52 3 7 PRF20 Treshold 2.5 5 2

3 Rise [bar/CAD] Rate Pressure Max 1.5 Relative Max Pressure Rise [bar/CAD] Rate Pressure Relative Max 1 64 1 0 5 10 15 20 25 30 1 1.5 2 2.5 3 3.5 4 Gross IMEP [bar] abs Inlet Pressure [bar] Idle

65 Efficiencies & Emissions

G. ON 69/66 G. ON 69/66 50 100 0.4 50 Gross Indicated Efficiency [%] NOx 48 99 45 Thermal Efficiency [%] 0.35 Soot 46 98 Combustion Efficiency CO 40 0.3 44 97 HC 35

42 96 0.25 30

40 95 0.2 25 [%] [%]

38 94 0.15 20 CO / HC [g/kWh] 36 93 NOx / Soot [g/kWh] 15 0.1 34 92 10 0.05 32 91 5

30 90 0 0 3 4 5 6 7 8 9 10 3 4 5 6 7 8 9 10 Combustion Phasing [TDC] Combustion Phasing [TDC]

66 Viability of Low ON Gasolines for PPC?

67 Oil Refineries Production Layout

50%

50 < ON < 75 90 < ON < 99

20%

Octane Number of the gasoline streams span68 from 99 to 50 RON  Gasolines with 70 RON are already produced!!! 30% Oil Refineries Perspectives

Oil refineries are a very stiff system and their kerosene, diesel and gasoline production can not be easily varied without major investments  we need to build highly efficient vehicles with the available fuels… 69 High ON Gasolines in Scania D13

What to do with these 25 fuels?! Still to be used in SI 20 engines?!

10 IMEP gross [bar] gross IMEP

0 20 30 40 50 60 70 80 90 100 RON [-]

70 Page 70 Minimum Turbo Efficiency

71 Ideal burn rate?

Conditions: 1. CA50: 8 [ATDC]. 2. CA90-10: 15 [CAD]. 3. Engine geometry: custom Scania D13. 4. Inlet temperature: 303 [K]. 5. Reference temperature: 298 [K]. 6. Engine speed: 1250 [rpm]. 7. Differential pressure exhaust minus inlet: 0.25 [bar]. 8. Cylinder wall temperature: 450 [K]. 9. Heat transferred modeled with the Woschni equation and tuned to match the experimental results 10. The rate of heat release has been approximated with a Wiebe function. 11. EGR is added in order to have 1.35 as λ. If the inlet pressure was not enough to have λ without EGR higher than 1.35, EGR was set to zero. 12. The combustion efficiency was assumed to be 100%. 13. Lower heating value 43.8 MJ/kg, stoichiometric air fuel ratio 14.68.

72 Exhaust Loss

73 Heat transfer loss

74 The rest (useful work)

75 Boosting reduce heat losses

76 A-B-C of Fuel Consumption

A. Car size B. Engine size C. Engine efficiency in right operating conditions

77 Porsche 911 performance with 100+ mpg?

• Two persons • 100 liter of storage capacity

78 Porsche 911 data

M=1550 kg Cr=0.012 Av=1.96 m2 Cd=0.33

Vd=3.8 liter P=355 PS (hp) T=400 Nm Performance 0-60: 4.6 s V,max=300 km/h ( 186.5 mph) Fuel consump.= 12.0 l/100 km (19.6 mpg)

79 Power needed @300 km/h (186.5 mph)

2 P = (CRmg + 0.5ρaCD Avv )v = 2   300    300   +  0.012x1550x9.81 0.5x1.2x0.33x1.96x  x    3.6    3.6  = 239.8kW = 326.1hp

80 The ”Cigar” Two person capacity is often enough

UK National Office of Statistics: “The average car occupancy is 1.6 people per car and for commuting it's 1.2 “

A carpool in California is a car with ONE person if the car is fuel efficient…

82 The ”Cigar” Existing large model use large BMW 1200 cc MC engine. With turbo a top speed of 315 km/h and fuel consumption of 3.5 l/100 km (67 mpg) http://www.peraves.ch/ Power needed @300 km/h (186.5 mph)

Cigar design specifications Cd=0.1 Av=0.5-1 m2 m= 250 kg Cr=0.012 (two wheels)

2 P = (CRmg + 0.5ρaCD Avv )v = 2   300    300   +  0.012x250x9.81 0.5x1.2x0.10x1.0x  x    3.6    3.6  = 37.2kW = 49.7hp

84 Power needed at 50 and 100 km/h (31- 62 mph)

Porsche 911 vs. cigar Speed (km/h) 911 Cigar Unit Ratio 50 3.57 0.57 kW 6.28 100 13.4 2.1 kW 6.36 300 239.8 37.2 kW 6.45

50 4.86 0.77 hp 6.28 100 18.2 2.9 hp 6.36 300 326.1 49.7 hp 6.45

Acceleration proportional to power/mass ratio: Cigar: 250/49.7=5.03 kg/hp 911: 1550/355=4.37 kg/hp

85 A. Car size • With more correct car size the engine size can be reduced a factor of 6 i.e. single cylinder version of 911 engine with 633 cc displacement is enough • Porsche 911 has a fuel consumption of 12 l/100 km (19.6 mpg) • Cigar would have 12/6=2 l/100 km (117.6 mpg) without any need of new engine technology. (Scaling both engine and car size)

86 B. Engine size • A Porsche 911 does not operate at optimum load points in normal driving. • At 50 km/h the estimated load is only 2 bar BMEP or less • Bsfc=400 g/kWh

(ηb=21 %)

0 20 40 60 80 100 120 140 160 180 200 220 87 Bilhast. [km/h] Engine downsizing Three options 1. Turbo or supercharge a small engine 2. Cylinder deactivation of large engine 3. Variable displacement i.e. variable engine size

88 B.1. Mercedes CDI 250, 2.1 liter

Vd=2143 cc Torque= 500 Nm (369 lb-ft)

89 Two stage turbo

90 Engine downsizing- MB 250 CDI Displacement of 2.1 liter giving 224 hp and 500 Nm of torque : 30 bar BMEP is now full load NOT 10 or 20 bar Fuel consumption; CO2: C-class 5.1 l/100 km (46.1 mpg), C-class 139 g/km E-class 5.3 l/100 km (44.4 mpg), E-class 143 g/km S-class 5.9 l/100 km (39.9 mpg) S-class 155 g/km

91 B2: Dual engine concept

• Use one small and one large engine • As an example: – One 2 cylinder 1 liter engine – One 4 cylinder 2 liter engine • This gives us 1, 2 or 3 liter to choose from

92 Layout 4 +2 cyl Fiat 2-cylinder production engine

FAS

Transm.

93 Operation

• 2-cyl at low loads • 4-cyl operation at higher load operation (Autobahn) • 6-cyl operation at highest loads • 6-cyl + FAS at transients (with FAS start of 4-cyl) • FAS for regenerative braking • FAS for lowest speed operation ( < 5 km/h) • Manual selection should be possible

94 B3: Variable displacement engine

• If we can change displacement, Vd, engine load, P, can be controlled without reducing BMEP! N P = bmep Vd nt

95 Atkinson Cycle

Displacement from 0.15 to 0.85 l per cylinder gives 0.6 to 3.4 l four cylinder engine at full load (@max BMEP)

96 Atkinson engine with variable displacement

97 Atkinson engine efficiency

98 Atkinson engine thermal efficiency

99 A-B-C of Fuel Consumption

A. Car size B. Engine size C. Engine efficiency in right operating conditions (Maximum engine efficiency)

100 Summary /ABC of fuel consumption

A. Correct car size gives factor of 6 in fuel consumption B. Correct load point gives factor 2 in fuel consumption (21%-42% or 400-200 g/kWh) C. Partially Premixed Combustion have the potential to extend brake efficiency to 50% with US10/Euro emissions. With further optimization 55% could be reached D. With waste heat recovery 60% should be possible giving a factor of 3 from today.

A total reduction potential of factor 18!

101 Cars and traffic situation

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