bengt johansson high efficiency kaust future fuels ... · lund university john a. gaynor ... what...

Future fuels

byBengt Johansson

Clean combustion research centerKAUST

Future fuels

2

EnergySource

Energy carrier

Energy usage

Well to Tank Tank to Wheel

Well to Wheel

Conventional path

3

Gasoline Mech. Energy

Ref. SICrude Oil

𝜂 = 88% 𝜂 = 35%

Diesel Mech. Energy

Ref. DieselCrude Oil

𝜂 = 88% 𝜂 = 45%

Improve engine efficiency

4

Gasoline /Diesel

Mech. Energy

Ref. 8-strokeCrude Oil

𝜂 = 88% 𝜂 = 60%

Gasoline /Diesel

Mech. Energy

Ref. PPCCrude Oil

𝜂 = 88% 𝜂 = 50%

Improve fuel processing

5

Naphtha Mech. Energy

Ref. PPCCrude Oil

𝜂 = 94% 𝜂 = 50%

Gasoline /Diesel

Mech. Energy

Ref. PPCCrude Oil

𝜂 = 88% 𝜂 = 50%

Biofuel with fermentation

6

Ethanol Mech. Energy

Ferm. SIBiomass

𝜂 = 30% 𝜂 = 35%

Biofuel with better ICE

7


Ferm. SIBiomass

𝜂 = 30% 𝜂 = 35%


Ferm. CIBiomass

𝜂 = 30% 𝜂 = 43%

Scania CI

8

Scania CI

9

Scania CI

10

Biofuel with better ICE

11


Ferm. SIBiomass

𝜂 = 30% 𝜂 = 35%


Ferm. CIBiomass

𝜂 = 30% 𝜂 = 43%


Ferm. PPCBiomass

𝜂 = 30% 𝜂 = 50%

Experimental Investigation on Different Injection Strategies

for Ethanol Partially Premixed Combustion

SAE 2013-01-0281

Mehrzad Kaiadi, Bengt Johansson, Marcus LundgrenLund University

John A. GaynorScania CV AB

Biomass Conversion via Syngas

13

Methanol Mech. Energy

PPCBiomass

𝜂 = 68% 𝜂 = 50%

Methanol PPC

14

Methanol = Liquid methane

15

Natural gas


PPCBiomass

𝜂 = 68%

𝜂 = 70 − 78%

𝜂 = 50%

Methanol cost less than LNG

17

Methanol cost less than LNG

18

Electrofuel

19

Natural gas


PPCBiomass

Electricity

𝜂 = 68%

𝜂 = 78%

𝜂 = ~70 − 80%

𝜂 = 50%

Electrofuels, really?

20


PPC

Electricity 𝜂 = ~70 − 80%

𝜂 = 50%

𝜂 = ~98%

With 100% renewable electricity

21

IF wind power should be sufficient also with low wind, we need much more power than average (1/capacity factor) and hence most of the time we have a surplus of energy.Use this surplus elctricity to make fuel (energy storage)

Wikipedia: “Capacity factor”

Example of How to Produce Electrofuels, Maria Grahn, Chalmers

Biomass(C6H10O5)

Electro-lysis

Water (H2O)

Hydrogen(H2)

H2

Electro-fuels Biofuels

Methane (CH4)Methanol (CH3OH)DME(CH3OCH3)Ethanol (C2H5OH)

CO2

Power

Allbiofuelproductiongenerates”waste CO2”

CO2 fromairandseawater

CO2 fromcombustion

Sabatierreactor

Biofuelproduction

Denmark already had periods with negative price on electricity

Tank-Wheel study

Review and Benchmarking of Alternative Fuels in Conventional and Advanced Engine Concepts

To be published in SAE 2016-01-0882

by Martin Tuner, Lund University

23

SAE 2016-01- 0882

24

Towards 60% efficient IC engine

byBengt Johansson


What is a high efficiency?

Any text book on ICE:• Ideal cycle with heat addition at

constant volume:

• With a compression ratio of 60:1 and γ=1.4 we get an efficiency of 80,6%

• Why then do engines of today have an efficiency of 20-40%???

26

Outline

• What is high efficiency?• Combustion, thermodynamic, gas exchange

and mechanical efficiencies. All four must be high.

• Combustion to enable high efficiency• HCCI• Partially Premixed Combustion

• Can we do something about engine design?

• Conclusions

Energy flow in an IC engine

FuelMEP

QhrMEP

IMEPgross

lMEPnet

BMEP

QemisMEP

QlossMEP

QhtMEP

QexhMEP

PMEP

FMEP

Combustion efficiency

Thermodynamic efficiency

Gas exchange efficiency

Mechanical efficiency

Net Indicated efficiency

Brake efficiency

Gross Indicated efficiency

FuelMEP

QhrMEP

IMEPgross

lMEPnet

BMEP

QemisMEP

QlossMEP

QhtMEP

QexhMEP

PMEP

FMEP

Combustion efficiency

Thermodynamic efficiency

Gas exchange efficiency

Mechanical efficiency

Net Indicated efficiency

Brake efficiency

Gross Indicated efficiency

ηηηηη MechanicaleGasExchangmicThermodynaCombustionBrake***=

Outline

• What is high efficiency?• Combustion, thermodynamic, gas exchange

and mechanical efficiencies. All four must be high.



• Conclusions

30

HCCI -Thermodynamic efficiencySaab 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=9.5:1Scania D12 Heavy duty diesel engine, HCCI, Rc=18:1;

Fuel: US regular Gasoline

SAE2006-01-0205

All four efficiencies

31

SAE keynote Kyoto 2007

Net indicated efficiency= ηC ηT ηGE

SI stdSI highHCCIVCR

Scania

+100%

Brake efficiencySI std

SI highHCCIVCR

Scania

Net indicated efficiency= ηC ηT ηGE

SI stdSI highHCCIVCR

Scania

47%

Outline• What is high efficiency?

• Combustion, thermodynamic, gas exchange and mechanical efficiencies. All four must be high.



• Conclusions

PPC - Diesel engine running on gasoline

0 2 4 6 8 10 12 1420

25

30

35

40

45

50

55

60

Gross IMEP [bar]

Gro

ss In

dica

ted

Effic

ienc

y [%

]

Group 3, 1300 [rpm]

FR47333CVXFR47334CVXFR47336CVX

HCCI: ηi=47% => PPC: ηi=57%

36

Partially Premixed Combustion, PPC

37

-180 -160 -140 -120 -100 -80 -60 -40 -20

1000

2000

3000

4000

5000

6000Spridare 8x0.12x90 & 8x0.12x150, Iso-oktan, CR-tryck 750 bar, Duration 0,6 ms = 3.6 CAD

HC

[ppm

]

SOI [ATDC]-180 -160 -140 -120 -100 -80 -60 -40 -20

200

400

600

800

1000

1200

NO

x [p

pm]

Def: region between truly homogeneous combustion, HCCI, and diffusion controlled combustion, diesel

HCCI

PPC

CI

SAE 2004-01-2990

PPC: Effect of EGR with diesel fuel

38

Load 8 bar IMEPAbs. Inlet Pressure 2.5 barEngine Speed 1090 rpm

Swirl Ratio 1.7Compression Ratio 12.4:1 (Low)

DEER2005 and SAE 2006-01-3412

Scania D12 single cylinder

1

43

2

40

PPC with low cetane diesel

Lic. Thesis by Henrik Nordgren2005 and presented at DEER2005

41

Efficiencies 17.1:1

4 5 6 7 8 9 10 11 12 1350

55

60

65

70

75

80

85

90

95

100

Gross IMEP [bar]

[%] Combustion Efficiency

Thermal EfficiencyGas Exchange EfficiencyMechanical Efficiency

SAE 2009-01-2668

42

4 6 8 10 12 14 16 1850

55

60

65

70

75

80

85

90

95

100

Gross IMEP [bar]

[%] Combustion Efficiency

Thermal EfficiencyGas Exchange EfficiencyMechanical Efficiency

Efficiencies 14.3:1

SAE 2010-01-0871

4343

4 6 8 10 12 14 16 180

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

Smok

e [F

SN]

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

0

0.1

0.2

0.3

0.4

0.5

0.6

Gross IMEP [bar]

NO

x [g

/kW

h]

GrossNetBrakeEU VIUS 10

2 4 6 8 10 12 14 16 180

1

2

3

4

5

6

7

8

9

10

Gross IMEP [bar]

CO

[g/k

Wh]


2 4 6 8 10 12 14 16 180

0.3

0.6

0.9

1.2

1.5

Gross IMEP [bar]

HC

[g/k

Wh]


Emissions

44

Emissions – different fuels

2 4 6 8 10 12 14 16 18 200

0.5

1

1.5

2

2.5

Gross IMEP [bar]

Soot

[FSN

]

EthanolFR47330CVXFR47331CVXFR47333CVXFR47334CVXFR47335CVXFR47336CVXFR47338CVX

2 4 6 8 10 12 14 16 18 200

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

Gross IMEP [bar]

NO

x [g

/kW

h]


2 4 6 8 10 12 14 16 18 200

2

4

6

8

10

12

Gross IMEP [bar]

CO

[g/k

Wh]


2 4 6 8 10 12 14 16 18 200

1

2

3

4

5

6

7

8

9

10

Gross IMEP [bar]

HC

[g/k

Wh]


SAE 2010-01-0871

4545

Experimental Apparatus, Scania D13

XPI Common RailOrifices 8 [-]

Orifice Diameter 0.19 [mm]

Umbrella Angle 148 [deg]

Engine / Dyno SpecBMEPmax 25 [bar]

Vd 2124 [cm3]

Swirl ratio 2.095 [-]

Standard piston bowl, rc: 17.3:1SAE 2010-01-2198

4620 30 40 50 60 70 80 90 1000

5

10

15

20

25

RON [-]

IMEP

gro

ss [b

ar]

Stable operational load vs. fuel typeTested Load Area

47

Efficiency with Diesel or Gasoline

5 10 15 20 25 3034

36

38

40

42

44

46

48

50

52

Gross IMEP [bar]

Brak

e Ef

ficie

ncy

[%]

D13 GasolineD13 Diesel

Average improvement of 16.6% points at high load by replacing diesel fuel with gasoline!

1.5 2 2.5 3 3.544

46

48

50

52

54

56

58G

ross

Indi

cate

d Ef

ficie

ncy

[%]

Abs Inlet Pressure [bar]

FR47338CVXFR47335CVXFR47334CVX

Gross Indicated Efficiency

SAE paper 2010-01-1471

10%!

Outline• What is high efficiency?

• Combustion, thermodynamic, gas exchange and mechanical efficiencies. All four must be high.



• Conclusions

High efficiency thermodynamics:Simulation results from GT-power

• Indicated efficiency 65,2%• Brake efficiency 60.5%

Is 65% possible?Any text book on ICE:• Ideal cycle with heat addition at constant

volume:

• With a compression ratio of 60:1 and γ=1.4 we get an efficiency of 80,6%

51

0 10 20 30 40 50 60 700

100

200

300

400

500

600

700

800

900

1000Peak cylinder pressure as function of compression ratio

Peak

cyl

inde

r pre

ssur

e [b

ar]

Compression ratio

Lambda = 1.2Lambda = 3.0

There are a few drawbacks…

– Engine structure must be very robust (if at all possible)

– Very high friction and hence lower mechanical efficiency

52

There are a few drawbacks…

530 10 20 30 40 50 60 7020

30

40

50

60

70

80

90Thermodynamic efficiency as function of compression ratio

Compression ratio

Ther

mod

ynam

ic e

ffici

ency

[%]

No heat transfer lossesWith heat transfer losses (Woschni)

How then make 60:1 usable?

• Swedish proverb: ”Den late förtar sig hellre än går två gånger”

• Which according to google translate means: ”The lazy man rather breaks his back than walk twice”

54

Take it in steps!How about

𝟔𝟎 = 𝟕. 𝟕𝟓If we divide the compression in two equal stages the total pressure (and temperature) ratio will be the product of the two

7.75:1 x 7.75:1=60:1

With a peak pressure of 300 bar the pressure expansion ratio is 300:1 and hence 300^(1/1.4)=58.8.1 in volume ratio(gamma=1.25 during expansion gives 96:1)

55

Split cycles from the past

56

From history: Compound Engine

Divide the expansion in three cylinders with same force, F, on each piston.

The smaller cylinder has higher pressure but also smaller areaF=p*A

57

Split cycles from the present

59

Three step compression in production• To run a smaller engine at

higher load turbocharging is used. The engine is using two or three shafts of which only one can generate power

• High BMEP (up to 30 bar) results with two-stage turbo

• Peak pressure 200 bar

60F. Steinparzer, W. Stütz, H. Kratochwill, W. Mattes: „Der neue BMW-Sechzylinder-Dieselmotor mit Stufenaufladung“, MTZ, 5,2005

Divide the process into two cylinders

Low pressure cycle

• Use large naturally aspirated engine designed for 30 bar peak pressure – Load range 0-5 bar

BMEP– Peak pressure during

the cycle 30 bar

• Friction FMEP 0.05-0.1 bar

High pressure cycle

• Use small engine with 300 bar peak pressure feed by the large engine

– Load range 35-80 bar BMEP

– Peak pressure during the cycle 250-300 bar

• Friction FMEP 1.2-2.2 bar

61

Principle layout 4 stroke + 4 stroke

62

Operating cycle 4 + 4 stroke

63

Inlet

Inlet

Inlet

Inlet

Compression Expansion

Compression

Compression

Compression Expansion

Expansion

Expansion

Exhaust

Exhaust

Exhaust

Exhaust

TDC TDCTDC

TDC

TDC

TDC TDC

TDC

TDCTDC BDCBDC

BDC BDC

BDCBDC

BDCBDC1

1

3

3

22

4 4

Pre

ssu

re

Combustion

DOUBLE COMPRESSION EXPANSION ENGINE CONCEPTS: A PATH TO HIGH

EFFICIENCY

Nhut Lam, Martin Tunér, Per Tunestål, Bengt Johansson, Lund University

Arne Andersson, Staffan Lundgren, Volvo Group

SAE 2015-01-1260

Conceptual design 4-4

65

SAE 2015-01-1260

Simulation study - Inputs

66

Simulation model DCEE DCEE Conv, Conv.Lambda, λ 1.2 3.0 1.2 3.0Bore, HP-cylinder [mm] 95 95 317 249Stroke, HP-cylinder [mm] 100 100 100 100HP-displacement [dm^3] 0.71 0.71 7.9 4.9Compr. ratio, HP-cylinder [-] 11.5 11.5 55 55Bore, LP-cylinder [mm] 317 249 - -Stroke, LP-cylinder [mm] 100 100 - -LP-displacement [dm^3] 7.9 4.9 - -Charge air cooler temp (K) 350 - - -

SAE 2015-01-1260

DCEE=Double Compression Expansion Engine

High Pressure cylinder

67

SAE 2015-01-1260

Low Pressure cylinder

68

SAE 2015-01-1260

Combined

69

SAE 2015-01-1260

Heat Transfer

• To reduce heat transfer: – Reduce heat transfer coeff., h– Reduce surface area, A– Reduce gas temperature– Increase wall temperature

70

!"!" = ℎ!!!(!! − !!)!

Wall surface area

710 1 2 3 4 5 6 7 8 9

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

Cylinder volume [dm3]

Area

[m2 ]

Wall surface area as function of cylinder volume

DCEE, lambda 1.2DCEE, lambda 3.0CI, lambda 1.2CI, lambda 3.0

SAE 2015-01-1260

Area/volume-ratio

72

0 1 2 3 4 5 6 7 8 90

200

400

600

800

1000

1200

Cylinder volume [dm3]

Area

/Vol

ume

[m2 /m

3 ]Wall surface area per volume as function of cylinder volume

DCEE, lambda 1.2DCEE, lambda 3.0CI, lambda 1.2CI, lambda 3.0

SAE 2015-01-1260

Heat transfer losses

73

SAE 2015-01-126074

Estimation of friction mean effective pressure, FMEP

0 50 100 150 200 250 3000

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8FMEP as function of PCP

FMEP

[bar

]

PCP [bar]Designed engine peak cylinder pressure

Naturally aspirated SI-engine @ 2300 rpm

Traditional heavy duty turbocharged CI engine

HP cylinder, DCEE-concept

LP cylinder, DCEE-concept

•Friction is assumed to scale with Peak Cylinder Pressure, Pmax

•FMEP assumed to be 1.2 bar @200 bar Pmax

SAE 2015-01-126075

Mechanical losses

Unit DCEE, λ=1.2

DCEE, λ=3.0

Conventional, λ=1.2

Conventional, λ=3.0

Peak cylinder pressure-LP cylinder bar 36 16-HP cylinder bar 300FMEP-LP cylinder bar 0.21 0.09-HP cylinder bar 1.8Total FMEP bar 0.34 0.31 1.8Net indicated work, IMEPn

bar 8.8 4.3 12.9 6.3

Mechanical efficiency % 96.1 92.8 86.0 71.6

Resulting Efficiencies

76

SAE 2015-01-1260

Summary• HCCI has shown high efficiency

– Up to 100% improvement in indicated efficiency vs. standard SI combustion

– Modest combustion efficiency– HCCI peaks at 47% indicated efficiency at around 6 bar

BMEP• PPC has shown higher fuel efficiency

– Indicated efficiency of 57% at 8 bar IMEP– Indicated efficiency of 55% from 5-18 bar IMEP– With 70 RON fuel we can operate all the way from idle to 26

bar IMEP

• With an effective compression/expansion ratio of 60:1 the split cycle concept shows 62% indicated/ 56% brake efficiency potential

77ηT =1−

1Rcγ−1

High Efficiency Combustion Engines – What is the limit?

“It all starts at 40 and ends at 60”(% engine efficiency that is, not life)

Prof. Bengt Johansson

CCRCKAUST

Thank you!

79

Future fuels

byBengt Johansson


bengt johansson high efficiency kaust future fuels ... · lund university john a. gaynor ... what...

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