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内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE) Combus’on mode design with high efficiency and low emissions controlled by mixture stra’fica’on and fuel reac’vity Presented by Prof. Yao Mingfa State Key Laboratory of Engines (SKLE), Tianjin University Feb 25, 2015 Future Powertrain Conference 2015

PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

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Page 1: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Combus'on  mode  design  with  high  efficiency  and  low  emissions  controlled  by    mixture  stra'fica'on  

and  fuel  reac'vity  

Presented  by  Prof.  Yao  Mingfa  State  Key  Laboratory  of  Engines  (SKLE),  Tianjin  

University  

Feb  25,  2015

Future  Powertrain  Conference  2015  

Page 2: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Tianjin University & SKLE •  The  first  ins'tu'on  of  higher  learning  in  the  history  of  

modern  Chinese  educa'on.    –  The  former  establishment  was  Peiyang  University  –  Founded  on  October  2,  1895    

•  One  of  the  na'onal  key  universi'es  directly  under  the  Ministry  of  Educa'on  of  China.  

•  Loca%on:  Tianjin:  the  third  largest  city  of  China,120  kilometers  southeast  away  from  Beijing    

Beijing Tianjin

2

 •  State  key  laboratory  of  engines  (SKLE)  

–  Founded  in  1989,  With  a  grant  from  China  Government  –  The  unique  state  key  laboratory  on  engine  research  in  

China  –  The  most  famous  center  in  China  on  research  and  

educa'on  in  advanced  engine  technology  –  Extensive  industrial  and  government  funding  

Page 3: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Funding from government and industry •  Projects  supported  by  MOST  

–  ‘973’  Key  Fundamental  Research  Plan  of  State-­‐8  universi'es  in  china  aZend  this  project,  such  Tsinghua  Univ.  Shanghai  Jiaotong  Univ.  etc  

•  Prof.  Su:  chief  scien'st.  PCCI,  LTC,  HCCI,  CAI,  Fuel  chemistry,  par'culate  forma'on  from  diesel  •  Prof.  Shu  :  chief  scien'st.  Exhaust  Heat  Recovery  of  engines  •  Prof.  Zhao:  chief  scien'st.    

–  ‘863’  Advanced  New  Technology  Plan  of  State  •  Diesel  development,  GDI  development,  alterna've  fuel  engine,  engine  control,  HV,  EV  

–  Interna'onal  collabora'on  sponsored  by  MOST  

•  Projects  supported  by  Na'onal  Science  Founda'on  of  China    –  Engine  combus'on,  aeertreatment,  combus'on  noise,  control,  alterna've  fuel  combus'on  

•  Interna'onal  collabora'on  project  sponsored  by  the  Foreign  Expert  Bureau  of  the  Chinese  State  Council  and  Educa'on  Ministry  of  China  

–  Some  Key  Technologies  for  the  Development  of  Efficient  and  Clean  Internal  Combus'on  Engines  

–  MIT,  Madison,  Berkeley,  Brunel,  London  city  univ.  Loughborough,  Lund,  Karlsruhe,Waterloo,  KAIST  of  Korea  

•  Projects  supported  by  industrial  corpora'on  •  Other  projects  supported  by  MOE,  Tianjin  government,  etc

15/2/26 3

Page 4: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Engine Research in SKLE •  16  Professors,  17  Associate  Professors  •  219  M.S  and  97  Ph.D  graduate  students  •  More  than  50  millions  Yuan  funding  per  year  from  government  and  industry  

15/2/26 4

Fuel Tech. & combustion

Advanced engine combustion tech..

Emissions & Aftertreatment

Noise, vibration,

structure & lubrication

Exhaust Heat Recovery

Engine Control

•  Wide range of advanced engines research is being carried out in SKLE

Page 5: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Recent Research Highlights(1/2) •  Fuel  and  fuel  combus'on  -  Bio-­‐fuel  technology  -  Fuel  physical  and  chemical  characteriza'on  -  Fuel  combus'on  kine'cs  -  Alterna've  fuel  combus'on  technology  

•  Diesel  engine  combus'on  -  Fuel  spray  &  fuel-­‐air  mixture  prepara'on  -  Mechanism  of  LTC  -  Compound  technology  for  HCCI  combus'on  (MULINBUMP)  -  High-­‐density,  Low  temperature  combus'on  (LTC)  for  diesel  engine  

•  Gasoline  engine  combus'on  –  HCCI/CAI  combus'on  technology  –  GCI  combus'on  technology  –  Mechanism  of  pre-­‐igni'on  for  down-­‐sizing  engine  –  GDI  engine  

15/2/26

Page 6: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Recent Research Highlights(2/2) •  Emissions  forma'on  and  aeer-­‐treatment  

–  Soot  forma'on  mechanism  –  Effects  of  PM  on  environment  –  SCR  and  PM  filter,  Lean  DeNOx  

•  Noise,  vibra'on,  structure  &  lubrica'on  –  NVH  technology  –  Engine  structure  and  design  

•  Engine  control  technology  –  Diesel  engine  control  –  Gasoline  engine  control  –  HV/EV  control  strategy  

•  Exhaust  heat  recovery    •  Fuel  cell     15/2/26 6

Page 7: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Academic exchange and collaboration •  InternaKonal  team �

15/2/26

§  Series international conference on engine combustion/engine control/fuel cell �

§  Seminar �

7

Page 8: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Student Activities

15/2/26

l  More  than  300  graduate  students  study  in  SKLE.    Engineers  from  industry  also  aOend  the  summer  school. �

8

Page 9: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Outlines •  Motivation •  Effects of combustion model on engine performance and

emissions •  Combustion model design fuelled with dual-fuel •  Conclusions

Page 10: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Challenges for HCCI combustion

•  HCCI combustion has the potential to be highly efficient and to produce low emissions.

•  However, controlling ignition timing is one of the challenges in the operation of HCCI engines

•  Controlling combustion rate (how to enlarge the operating range) is another challenge in the attempt to take advantage of HCCI technique.

•  It is also necessary to improve combustion efficiency and decrease high THC and CO emissions

Page 11: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Effects of fuel properties on HCCI

•  Fuel  RON  affect  the  efficiency  •  Fuel  RON  affect  the  opera'ng  

range  •  Note:  port-­‐injec'on  

Mingfa  Yao  Combus'on  Science  &  Technology    2007,  179(12):  2539-­‐2559  

Mingfa  Yao    Energy  &  Fuels  2008,  22,  2207–2215  

•  Varying  fuel  RON  can  enlarge  HCCI  opera'on  regions  and  get  high  thermal  efficiency  

–  Low  load-­‐high  cetane  number  fuel  –  High  load-­‐high  octane  number  fuel  

•  It  is  difficult  that  one  fuel  meet  both  low  load  and  high  load  demands 0.34

0.34

0.29

0.240.19

0.39

0.44

0.49

0 10 20 30 40 50 60 70 80 902.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

Knocking Limit

0.54

0 10 20 30 40 50 60 70 80 902.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0n=1400 / r/min IMEP / Mpa

0 10 20 30 40 50 60 70 80 902.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

λ fuel

RON

Page 12: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

HCCI controlled by charge stratification

•  Port  injec'on  +  Direct  injec'on,  PI/DI  ra'o  and  'ming  affect  the  charge  stra'fica'on  

•  HC  decrease,  CO  and  NOx  increase  for  stra'fica'on  

Mingfa  Yao  Fuel  88  (2009)  354–365  

Page 13: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Mixture reactivity enlarges HCCI operation range

•  Dual  fuel  by  port  injec'on:  High  cetane  fuel  +  high  octane  fuel  

•  Change  mixture  reac'vity  by  dual  fuel  ra'o,  then  control  HCCI  combus'on  processes  

•  By using DME/methanol dual fuel, HCCI can be operated over a fairly wide engine speed and load range  

Mingfa  Yao  Fuel  85  (2006)  2046–2056  

0.540.48

0.420.37

0.320.27

0.25

0.230.21

4 6 8 10 12 14 16 18 20 22 24

4

5

6

7

8

9

1400 r/min IMEP/MPa

Partial Burn

Knocking LimitDM

E E

xces

s A

ir R

atio

λD

ME

Methanol Excess Air Ratio λMEOH

0.740.65

0.59

1000 1200 1400 1600 1800 2000 22000.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

IMEP

(MPa

)

Engine Speed(r/min)

DME DME+CNG DME+MeOH

Page 14: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

DME Port injection + Methanol Direct Injection

-40 -20 0 20 40 60 80 100

0

50

100

150

200

0

2

4

6

8

10

12

Crank Angle /deg.C

ylin

der P

ress

ure

/Mpa

Hea

t Rel

ease

Rat

e /

J.C

AD

-1

DME%=29.4DME%=21.0DME%=17.0DME%=12.0DME%=10.4

n=1400r/minImep=0.84Mpa

DME%=29.4DME%=21.0DME%=17.0DME%=12.0DME%=10.4

Compound  combusKon:  HCCI:(LTR  of  DME+HTR  of  DME)+Diffusion  combusKon  (Heat  release  of  Methanol)    Engine  can  work  in  full  load  mode,  low  HC  and  CO  emissions,  NOx  emission  can  be  controlled  by  methanol  injec'on  strategy

-70 -60 -50 -40 -30 -20 -10 0

0

500

1000

1500

2000

2500

喷 射 时 刻 / οCA ATDC

φMEOH=0.5 φMEOH=0.338 φMEOH=0.119

N

OX

排放

/ ppm

爆 震

部 分 燃 烧

Reactivity + charge stratification

Mingfa  Yao,  Energy  Fuels,  2009,  23  (5),    2719–2730  

Page 15: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Motivation & objective •  Wisconsin,  SAE  2009-­‐01-­‐1442  

–  No  tradi'onal  PM/NOx  tradeoff  –  Approach  2010  EPA  HD  truck  emission  

standards  in-­‐cylinder  at  11  and  6  bar  net  IMEP  

–  Low  ISFC  and  MPRR  –  Tradi'onally  DI  or  SI  for  full  load  

•  It  is  poten'al  to  achieve  high  thermal  efficiency  for  gasoline/diesel  dual-­‐fuel    

•  If  the  dual  fuel  can  be  used  to  control    combus2on,  how  to  op2mize  the  combus2on  in  full  load  range?  Especially,  diesel/CNG  or  diesel/methanol  dual  fuel.

Source  from  Reiz

Page 16: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Outlines •  Motivation •  Effects of combustion model on engine performance and

emissions •  Combustion model design fuelled with dual-fuel •  Conclusions

Page 17: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Effects of combustion mode on performance and emissions

•  Test  fuel:  diesel  (20%)  +  gasoline  (80%)  •  CombusKon  mode: (HPCC-­‐Highly  Premixed  Charge  CombusKon)  

–  E-­‐HPCC:  20%  diesel  early  direct  injecKon  +  80%  gasoline  port  injecKon  –  L-­‐HPCC:  20%  diesel  late  direct  injecKon  +  80%  gasoline  port  injecKon  –  LTC:  20%diesel  +80%  gasoline  mixture  direct  injecKon  

•  Heat  release  control:  the  same  CA50,  CA50=8CA  ATDC  •  Cycle  fuel:  50mg;  engine  speed:  1500r/min  

-50 -40 -30 -20 -10

0

2

4

6

8

10

Early injection

SOI (° ATDC)

CA

50 (°

ATD

C)

Late injection

EGR=40%

E-­‐HPCC L-­‐HPCC

Page 18: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Stratification & reactivity for early or late injection

Diesel    SOI

Reac'vity

Stra'fica'on

Early-­‐  injec'on  

Late-­‐  injec'on  

Page 19: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Indicated Thermal Efficiency

30 35 40 45 5040

42

44

46

48

50

Indi

cate

d Th

erm

al E

ffici

ency

[%]

EGR [%]

E-HPCC L-HPCC LTC

The three combustion modes have little difference in indicated thermal efficiency

Page 20: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Thermal Efficiency Analysis (1)

30 35 40 45 50400

420

440

460

480

500

Exha

ust T

empe

ratu

re [℃]

EGR [%]

E-HPCC L-HPCC LTC

  The exhaust temperature of LTC is highest, resulting in the highest exhaust heat

  Exhaust heat can be recovered by Turbo-charger

30 35 40 45 5090

92

94

96

98

100

Com

bust

ion

Effic

ienc

y [

%]

EGR [%]

E-HPCC L-HPCC LTC

  E-HPCC and L-HPCC combustion efficiencies are almost the same, it indicates that the port injection of gasoline go into the quench area and can not be burned completely   The combustion efficiency of LTC is higher than the other two combustion modes

Page 21: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Thermal Efficiency Analysis (2)

0

10

20

30

40

50

Perc

ent F

uel E

nerg

y

E-HPCC L-HPCC LTC

Gross Ind.Efficiency

Heat TransferExhaust Comb. Loss

44.1 44.6 44.2

35.136.8 37.8

17.114.9

16.8

3.8 3.71.2

  The  exhaust  heat  of  LTC  is  the  highest  

  The  heat  transfer  of  L-­‐HPCC  is  the  lowest  

  The  combus'on  efficiency  of  E-­‐HPCC  and  L-­‐HPCC  is  lower  than  LTC  

Page 22: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

NOX & soot Emissions

30 35 40 45 500.0

0.2

0.4

0.6

0.8

1.0

soot

[10

-2g/

kWh]

EGR [%]

E-HPCC L-HPCC LTC

  NOX  emission  of  L-­‐HPCC  and  LTC  could  be  reduced  drama'cally  by  EGR      E-­‐HPCC  mode  can  aZain  ultra-­‐low    NOX  emission  which  is  insensi've  to  EGR  

  Three  combus'on  modes  bring  in  a  smokeless  way  in  spite  of  EGR    Early  port  injec'on  of  80%  gasoline  and  long  igni'on  delay  of  fuel  make  the  soot  emission  low  enough  to  meet  stringent  legisla'on    

NOX of E-HPCC is not sensitive to EGR 30 35 40 45 50

0.0

0.5

1.0

1.5

2.0

2.5

3.0IS

NO

X [g/k

Wh]

EGR [%]

E-HPCC L-HPCC LTC

Page 23: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Combustion Analysis by CFD

CA10(diesel)

E-HPCC

L-HPCC

LTC

CA50(Temp.) E-HPCC

L-HPCC

LTC

Page 24: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Summary •  LTC  fuelled  with  blended-­‐fuel  with  80%  gasoline  and  20%  diesel  

–  Highest  heat  release  rate,  highest  MPRR  –  Lowest  HC  emissions,  highest  combus'on  efficiency  –  CO  and  NOx  emissions  strongly  depend  on  EGR  ra'o  

•  E-­‐HPCC  –  Lowest  NOx  and  soot  emissions,  in-­‐sensi've  to  EGR,  mainly  from  upper  piston  

areas  –  Lowest  exhaust  temperature  –  EGR  can  enlarge  the  opera'on  region  –  Soot  can  be  generated  from  the  impingment  fuel  (depending  on  injected  fuel,  

injec'on  'ming,  EGR  ra'o)    

•  L-­‐HPCC  –  Lowest  heat  release  rate,  lowest  MPRR  –  NOx  emissions  depend  on  EGR,  but  CO  is  insensi've  to  EGR  except  high  EGR  ra'o  –  NOx  and  soot  emissions  are  mainly  formed  in  diesel  spray  region    –  Poten'al  in  high  and  full  load  mode  

Page 25: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Outlines •  Motivation •  Effects of combustion model on engine performance and

emissions •  Combustion model design fuelled with dual-fuel •  Conclusions

Page 26: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Combustion characteristics fuelled with dual-fuel •  Flexible  fuel  and  mixture  

prepara'on  –  Port  injec'on/DI  injec'on  –  High octane fuel + high cetane fuel  

•  Combus'on  was  controlled  by  stra'fica'on  &  mixture  reac'vity –  Fuel (mixture) reactivity control –  Fuel stratification (injection strategy) –  Combustion model design

Fuel with high octane number

Fuel with high cetane number

Diesel    SOI

Single  injec'on

Reac'vity Stra'fica'on  for  diesel

Double  injec'on

Reac'vity Diesel    SOI2

First  injec'on  (SOI1):  early  injec'on,  reac'vity

Stra'fica'on  for  diesel

Small  load    Reac'vity

Stra'fica'on  for  diesel

High  load    

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内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Combustion mode design fuelled with dual-fuel

•  Large  &  full  load  combusKon  –  CI  (High  CR)  or  SI  (Low  CR)  –  VVT+LTC(High  cetane  fuel)  or  VVT+PPC  

(high  octane  fuel)  –  Diesel  ignites  gasoline  (Late  diesel  

injec'on,  L-­‐HPCC)-­‐  QHCCI  

Hybrid combustion mode design:

•  Small load combustion -  Diesel (high cetane fuel) PCCI (LTC) -  VVT+GCI (high octane fuel) -  Diesel and gasoline dual fuel

•  Middle load combustion •  Diesel and gasoline dual fuel: diesel early

injection, high gasoline ratio (E-HPCC)

Flexible  fuel                          Flexible  combusKon  mode

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内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Combustion mode design fuelled with dual-fuel

•  Small  load-­‐  – Diesel  PCCI/LTC  

•  Middle  load  – Diesel/gasoline  dual-­‐fuel    HCCI:  diesel  early-­‐injec'on  or  double-­‐injec'on(early  SOI2)  

•  High  load  &  Full  load  – Diesel/gasoline  dual-­‐fuel  QHCCI:  diesel  double  –injec'on  (late  SOI2)  

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内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Combustion optimization •  CombusKon  control  parameters  

– Gasoline/diesel  ra'o  – Diesel  injec'on  strategy  – EGR  ra'o  

•  OperaKon  region  limit  – MPRR<1.0MPa/CA  (Knocking  limit)  – COVimep<5%  (misfire  limit)  – NOx<0.4g/kW.h  (NOx  limit)  – Smoke  opacity<5%  (Smoke  limit)

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内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Diesel/gasoline dual-fuel: diesel injection strategy Combus'on  Control  -­‐  The  same  main  combus'on  posi'on  (CA50  

control)    -­‐  The  same  Rg,  EGR  ra'o,  SOI1,  injec'on  fuel  -­‐  E-­‐SOI2:  longer  igni'on  delay,  well-­‐premixed  -­‐  L-­‐SOI2:  shorter  igni'on  delay,  stra'fica'on    

-50 -40 -30 -20 -10 00

2

4

6

8

10

12SOI1=-55(°CA ATDC)

SO2/(°CA ATDC)

CA

50/(

°CA

ATD

C)

SOI2

Early-­‐  SOI2 Late-­‐  SOI2

-30 -20 -10 0 10 20 300

2

4

6

8

10

12

0

100

200

300

Com

bust

ion

Pres

sure

/MPa

Crank Angle/(°CA ATDC)

CA50: 6°CA ATDC L-SOI2 E-SOI2 Single

Hea

t Rel

ease

Rat

e/(J

/°C

A)

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内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE) -­‐31-­‐  

•  High  EGR  rate  is  required  for  reducing  the  NOx  emissions,  especially  for  L-­‐SOI2.  

30 35 40 450.00.20.40.60.8

1761781801821841860

-20-40-60-80

0.000.02

0.10So

ot/(g

/kW·h)

L-SOI2 E-SOI2 Single

EGR/%

0

2

4

6

CO/(g

/kW·h)

2

4

6

8

THC/

(g/k

W·h)

0.30.60.91.21.5

M

PRR/

(MPa

/°CA)

NOx/

(g/k

W·h)

ISFC

/(g/k

W·h)

SOI2

/(°CA

ATD

C)

•   L-­‐SOI2:  the  lowest  maximum  heat  release,  two  stages  HTHR,  longest  combusKon  duraKon  –  the  charge  is  more  straKficaKon  

for  L-­‐SOI2  than  E-­‐single  and  E-­‐SOI2  

–  More  straKficaKon,  more  sensiKve  to  EGR  for  NOx  emissions

Diesel/gasoline dual-fuel: diesel injection strategy

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内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Double injection strategy

SOI1: the first injection fuel improves the mixture reactivity, more early injection, more homogeneous mixture. It is necessary to improve the reactivity for second injection ignition.

SOI2:  the  second  injec'on  fuel  will  trigger  the  combus'on  because  of  the  stra'fica'on。

Page 33: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Extend operation by late-SOI2

0

20

40

60

80

柴油喷油量 (mg/cycle)

柴油

汽油

8 10 12

808386899295

140120100

汽油比例

(%)

总喷油量

(mg/

cycl

e)

80

喷油压力 (MPa)1.1

1.2

1.3

1.4

0.6

0.8

1.0

1.2

IMEP

(MPa

)

MPR

R (M

Pa/°

)

EGR/% 45

SOI1/°ATDC -55

Mass of diesel /(mg/cycle) 8,10,12

CA50/°ATDC 8~9

Injection pressure/MPa 80,100,120,140

•  Improve  injec'on  pressure  (140MPa,  Max  IMEP=1.39  MPa) –  More  homogeneous  mixture –  Improve  gasoline  ra'o,  but  it  is  

necessary  to  inject  enough  diesel  for  improving  combus'on  stability.    

•  Opera'on  range  was  limited  by  soot  emission,  how  to  decrease  soot  emission?

•  Fuel  physics  properity  (improve  mixture)

•  Oxygen  fuel  ? •  VVA-­‐  delay  intake  valve  closing  'ming  •  ……  

Page 34: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Compare operation range of different injection strategies

0.91.01.11.21.31.41.5

最大

IMEP

(MPa

)

E-Single E-SOI2 L-SOI2

1.0

1.1

1.2

1.3

MPR

R(M

Pa/°

CA

)

0.0000.0010.0020.0030.0040.005

Soot(g

/(kW·h

))

170

175

180

185

ISFC(g

/(kW·h

))

l  Max  IMEP  and  it’s  constraint  factor:  •   E-­‐single:1.026  Mpa,High  MPRR  &  pressure    •   E-­‐SOI2:1.027  Mpa,High  MPRR  &  pressure    •   L-­‐SOI2:1.391  Mpa,High  soot  emission

Injection strategy E-single E-SOI2 L-SOI2

SOI1/°ATDC -58 -55

SOI2/°ATDC -35 -31 -8

EGR/% 42.5 42.5 42.5

Gasoline /% 81.7 81.3 87.5

Injection pressure /MPa 80 80 140

soot(g/(kW·h)) 0.0014 0.0024 0.005 NOx/(g/(kW·h)) 0.17 0.21 0.11

CO/(g/(kW·h)) 3.17 3.35 7.09

THC/(g/(kW·h)) 3.78 4.14 4.07

Page 35: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Effects of CN of DI fuel

0.05

0.10

0.15

0

1

2

3

4

2468

1012

-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0468101214

CN34 CN43 CN56 CN100

SOI (°CA ATDC)

smok

e (F

SN)

NO

x (g

/kw

.h)

HC

(g/k

w.h

)

CO

(g/k

w.h

)

456789

4445464748

15

20

25

30

-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 020

30

40

50

60

CN34 CN43 CN56 CN100

MPR

R (b

ar/°

CA

)

Indi

cate

d ef

ficie

ncy

(%)

Com

bust

ion

Dur

atio

n (°

CA

)

EGR

(%)

SOI (°CA ATDC)

Page 36: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

0.100.09

0.13

0.15

0.08

0.170.19

0.090.10

0.12

0.13

0.16

0.080.07

0.06

0.110.13

0.21

0.29

0.086

0.54

0.70

0.076

0.79

0.95

0.066

1.0

1.1

0.055 1.2

0.10

0.12

0.08

0.170.21

0.06

0.29

0.050.040.37

72

76

80

84

88

92

Rg

(%)

72

76

80

84

88

92

Rg

(%)

knocking limitmissing fire limit

NOx ( g/kwh) --1700rpm;inj.pres.=80MPa

-65 -60 -55 -50 -45 -40 -35 -3072

76

80

84

88

92

NOx limit smoke limitmissing fire limit

Diesel SOI (°CA ATDC)

Rg

(%)

72

76

80

84

88

92

Rg

(%)

knocking limitmissing fire limit

EGR=0

EGR=40%

EGR=50%

EGR=60%

knocking limit smoke limitmissing fire limit

7.8

7.3 6.4

5.5

3.7

2.8

2.3

1.9

1.7

1.4

1.41.3

1.71.9

1.2

1.3

1.2

1.1

3.5

3.1

2.7 2.01.1

0.90

0.57

0.52

7.56.9

6.2

5.6

4.4 3.7

3.1

2.5

2.01.5

1.2

1.5

0.9 0.8

0.7

3.37

2.932.61

2.28

1.84

1.400.97

0.75

0.53 0.42

0.34

-65 -60 -55 -50 -45 -40 -35 -3072

76

80

84

88

92

NOx limit smoke limitmissing fire limit

Diesel SOI (°CA ATDC)

Rg

(%)

72

76

80

84

88

92

knocking limitmissing fire limit

knocking limitmissing fire limit

Rg

(%)

72

76

80

84

88

92

knocking limit smoke limitmissing fire limit

opacity N (%)--1700rpm;inj.pres.=80MPa

Rg

(%)

72

76

80

84

88

92

EGR=0

EGR=40%

EGR=50%

EGR=60%

Rg

(%)

178.1

177.3177.3

178.1

175.9175.5

175.0174.6

174.2

175.5

174.9

174.1

176.1

175.5

173.8173.5

173.2

173.1

172.9

173.8

172.8

173.5

173.0

174.0

174.2

174.5

174.8

172.7

172.4

172.2

171.9

175.2

174.6174.1

173.5

172.7

172.3

172.1

172.1

-65 -60 -55 -50 -45 -40 -35 -3072

76

80

84

88

92

NOx limit smoke limit missing fire limit

ISFC (g/kWh)--1700rpm;inj.pres.=80MPa

Diesel SOI (°CA ATDC)

Rg

(%)

72

76

80

84

88

92

knocking limit smoke limitmissing fire limit

Rg

(%)

72

76

80

84

88

92

EGR=0

EGR=40%

EGR=50%

EGR=60%

Rg

(%)

72

76

80

84

88

92

knocking limit missing fire limit

knocking limitmissing fire limit

Rg

(%)

Best  ITE

There  are    a  wide  high  efficiency    range  with  ultra-­‐low  NOx  and  smoke  

Lowest  NOx

Lowest  smoke

Combustion optimization

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内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

230

240

250

260

270

280

290

266262 .45

258 .89

2 75

268. 22 72

2 65. 8

28 3

2 87. 6

con

vent

ional

diese

l co

mbus

tion

HPCC

Dou

ble i

nject

ion

HPC

C Si

ngle

inje

ction

PCCI

Dou

ble i

nject

ion

PCCI

Sin

gle i

njec

tion

BSF

C/(g

/kW⋅h

)

Combustion modes

OEMw/o EGR

H ig h-p re ssureEGR

Lo w-press ureEGR

PCC

I Dou

ble i

njec

tion

PCC

I Sing

le inj

ectio

n

HPC

C Dou

ble i

njec

tion

HPC

C Si

ngle

inje

ction

19 00 r/min, 0 .2 5MPa BMEP

Combustion modes comparison under the low load condition(CR=17.5) PCCI Pinj=1200bar, HPCCP inj=800bar

Combustion mode design in a 4-cylinder engine

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内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Higher efficiency than diesel engine without Nox control

320290260245

230

223

217

211

350

208

208

380 410

230

50

100

150

200

250

300

350

90kW80kW70kW60kW

50kW40kW30kWTo

rque£N̈¡¤m£©

20kW

100012001400160018002000220024002600280030003200

CR14+FG100Ó ÐÐ §Ó ͺ Ä ÊÍ òÓ ÐÌ ØÐ Ô

Speed£ r̈/min£ ©

BSFC (g/kW.h)

BMEP<0.5MPa PCCI-diesel fuel (diesel early injection with heavy EGR) BMEP=0.5~1.1MPa Diesel-gasoline dual fuel HCCI (diesel early injection) BMEP>1.1MPa QHCCI (diesel late injection near TDC)

Hybrid combustion control�

diameter 96 mm

stroke 103 mm

Cylinder number 4

displacement 2.982L

Compression ratio 14.0

Rated power 95 kW

Rated speed 3200 r/min

Maximum torque 340N·m

Max. torque speed ≤2400 r/min

Engine specifications � 

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内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Ultra-low NOx & Soot emissions

39

NOx emissions (g/kW.h)

Soot emission (FSN)

•  Ultra-low NOx & Soot emissions with high efficiency can be achieved. In order to meet Euro VI emission regulation, does gasoline-tank replace urea-tank?

•  For engine map, it includes different combustion modes. High efficiency & ultra-low emissions can be achieved by combustion mode design.

•  It can be operated different fuels with high-octane and high-cetane fuel, such as bio-diesel, n-butane, natural gas, methanol, ethanol, DME etc.

1.01.00.80

0.400.30 0.20

0.20

0.30

0.40

0.40

0.10

0.80 0.80

1.01.0

1.0

1.0

0.10

0.40

0.300.30

0.300.30

0.10

0.30

0.20

0.4

0.6

0.8

1.0

1.2

1.4

90kW

80kW

70kW

60kW

50kW

40kW

30kW

BMEP(MPa)

20kW

NOx(g/kW⋅h)

1200 1600 2000 2400 2800 3200

Speed(r/min)

0.02

0.02

0.020.050.1

0.2

0.05

0.4

0

0.1

0.6

0.05

0.7

0.2

00

0.4

0.1

0.4

0.2

0

01200 1600 2000 2400 2800 3200

0.4

0.6

0.8

1.0

1.2

1.4

90kW

80kW

70kW

60kW

50kW

40kW

30kWBMEP(

MPa)

20kW

Speed(r/min)

Smoke(FSN)

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内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

1000 1200 1400 1600 1800 2000

4

6

8

10

12

14

16

18平均有效压力/bar

转速/rpm

31.90

33.51

35.11

36.72

38.33

39.93

41.54

43.14

1000 1200 1400 1600 1800 2000

4

6

8

10

12

14

16

18

平均有效压力/bar

转速/rpm

31.90

33.51

35.11

36.72

38.33

39.93

41.54

43.14>45%

Diesel  engine

46.58%

Methanol/diesel  dualfuel

Compared  the  BTE  of  diesel  and  methanol/diesel  dual  fuel

Results  From:  Prof.  Yao  Chunde,  SKLE,  Tianjin  University

40

43%

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内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Outlines •  Motivation •  Effects of combustion model on engine performance and

emissions •  Combustion model design fuelled with dual-fuel •  Conclusions

Page 42: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Conclusions •  Dual  fuel  combus'on  is  essen'ally  controlled  by  mixture  

stra'fica'on  and  reac'vity,  different  combus'on  mode  can  be  achieved  by  controlling  injec'on  strategy,  dual  fuel  ra'o  and  EGR  

•  Smart  combus'on  mode  (hybrid  combus'on)  can  be  achieved    by  dual-­‐fuel  to  get  high  efficiency  with  ultra-­‐low  NOx  and  Soot  emissions.  Combustion design strategy: –  Idle & low load mode: PCCI with high cetane fuel + VVT (early intake valve

close timing) +EGR –  Small to middle/high (BMEP=1.2MPa) load mode: RCCI with dual fuel

+EGR –  High/full load mode: PPC with high octane fuel + VVT (retard intake valve

close timing, miller cycle) + EGR  •  Combus'on  mode  design  will  be  first  applied  in  alterna've  fuels,  

such  as  natural  gas,  methanol  etc.  VVT  system  is  another  important  control  parameter  for  combus'on  mode  design.  

Page 43: PresentedbyProf.Yao( Mingfa( …Fuel Tech. & combustion Advanced engine combustion tech.. Emissions & Aftertreatment Noise, vibration, structure & lubrication Exhaust Heat Recovery

内燃机燃烧学国家重点实验室 State Key Laboratory of Engines (SKLE)

Thanks for your attention!