Outline - Energimyndigheten

Report
High Efficiency Combustion
Engines – What is the limit?
Prof. Bengt Johansson
Lund University
Outline
• Introduction
• The future is hard to predict
• Options
• Other combustion engines?
• Fuel cells?
• Batteries?
• Combustion engines
• What is high efficiency?
• Combustion, thermodynamic, gas exchange and mechanical
efficiencies. All four must be high.
• What options do we have?
• Combustion to enable high efficiency
•
•
•
•
Spark Ignition
Compression Ignition
HCCI
Partially Premixed Combustion
• Can we do something about engine design?
• Conclusions
Today
100.0%
of all cars and trucks have
internal combustion engines
The total fleet is about 1.000.000.000 cars and trucks
The electric fleet is less an 1.000.000 i.e. 0.1%
“Prediction is very difficult especially
if it is about the future”- Niels Bohr
http://wattsupwiththat.com/2014/07/27/prediction-is-very-difficult-especially-about-the-future/
Newsweek April 28, 1975
5
”Den som ser framåt utan att se bakåt får se upp” Per Gillbrand
Car of the future 1950-60: Gas turbine
Car of the future 1950-60: Gas turbine
“Timetable for Next Car Engine : The Gas
Turbine and Its Future” Business Week, April 2,
1955, page 134+
THEY ESTIMATE by
1960 .................60,000 - 300,000 cars
1965 ................264,000 - 3,900,000
1970 .............11,500,000 - 42,500,000
1975 .............48,000,000 - 62,000,000
http://fuel-efficient-vehicles.org/energy-news/?page_id=943
Car of the future 1970: Stirling
Car of the future 1980: ….
Car of the future 1990: Battery Electric
GM EV-1
Car of the future 2000: Fuel Cell
Car of the future 2000: Fuel Cell
“It is generally accepted that fuel cell vehicle production will follow a timeline as follows:
Starting in 2002-4:
• First production FCVs tested on public roads in US, Europe and Japan in demonstration
fleets.
Around 2006-2007
• Second generation fuel cell systems incorporated into FCVs and the expansion of FCV
fleets in the US, Europe and Japan.
Starting in 2010
• Marketing of commercially viable FCVs at affordable prices - this will be the first step
toward ultimately replacing the conventional internal combustion engine models.”
August 29, 2002, Bloomberg News :
”Larry Burns, GM’s vice-president for R&D: “GM’s goal is to be the world’s first company to
produce one million fuel cell vehicles a year,” and that GM is looking to sell hundreds of
thousands of fuel cell vehicles between 2010 and 2020
http://www.engr.uconn.edu/~jmfent/AutoCompaniesonFuelCells.pdf
Car of the future 2010: Battery Electric
Carlos Ghosn CEO Renault/Nissan 2010: “Nissan Will Sell 500,000 Electric Cars a Year by 2013”
He predicted that 10 percent of the world car market would be electric vehicles by 2020.
“There is no doubt in the minds of anyone in the industry that this is going to be a big factor in
the industry,” he said.
Car of the future 2010: Battery Electric
Reuters news flash Sept 14 2014:
Nissan faces battery plant cuts as electric car hopes fade
Ghosn dropped extra battery sites
planned for both alliance
carmakers, leaving Nissan with
the entire production capacity of
220,000 power packs through the
NEC joint venture, AESC.
But that still far exceeds the
67,000 electric cars RenaultNissan sold last year, and even
the 176,000 registered to date. A
pledge to reach 1.5 million by
2016 has been scrapped.
Toyota: Elbilen behöver Nobelprisbatteri
Tekniken som behövs för att göra elbilar
användbara är inte uppfunnen än
- Körsträckan är så kort med en elbil, och laddtiden
är så lång, summerar Kato. Med den tekniknivå vi
befinner oss på i dag behöver någon uppfinna ett
batteri så bra att det vinner Nobelpris.
För att kunna konkurrera med dagens bensindrivna
bilar behövs så mycket batterier att det ökar
kostnaderna och laddtiderna.
- Antalet kunder som är nöjda med elbilens korta
räckvidd är begränsad, säger han. Men blir intresset
för sådana bilar plötsligt större, då är vi beredda att
leverera.
Av: Håkan Abrahamson, Ny teknik 10 juli 2014
16
Toyota: Elbilen behöver Nobelprisbatteri
I en intervju i Automotive News ger han tummen
ner för satsningen på elbilar, och säger att Toyota
nu lägger sin tillverkning av elbilar.
Företaget tror att alternativet till bensin och diesel
heter vätgas. Nästa år lanserar Toyota en
bränslecellbil, och även andra tillverkare ligger
startgroparna med den sortens drivning.
- Vid det laget erbjuder Toyota inte längre någon
helt eldriven bil, säger Kato. De små serier av
elbilar som nu finns på programmet, minibilen eQ
och RAV4 EV, läggs ner i slutet av det här året.
Av: Håkan Abrahamson, Ny teknik 10 juli 2014
17
Battery performance
“The active material
for the anode and
the cathode which
are assumed to be a
carbon-based
anode (~2.7 g/Ah)
and a Co-based
cathode (~7.3 g /Ah)
for the Li-ion cell.
The specific
capacity of the
couple is therefore
~100 Ah/kg which
combined with
the voltage of 3.85
V for this couple
leads to the 385
Wh/kg number”
Source: Private communications with Prabhakar Patil, CEO, LG
Chem, Battery Div. Nov. 4, 2011
18
Li-ion battery performance is now at
52% of theoretical limit
40/250=0,160
55/245=0,225
55/315=0,175
70/370=0,189
80/240=0,333
20/810=0,025
20/135=0,148
70/570=0,123
180/790=0,228
130/459=0,283
200/385=0,519
Source: Private communications with Prabhakar Patil, CEO, LG
Chem, Battery Div. Nov. 3, 2011
19
Electric Vehicle – Storage capacity
900
E n erg y D en sity (W h /l)
800
ZM P
A g -Z n
700
Energy density increased 1 order of
magnitude
600
500
400
Specific energy increased a factor of 4-5
L i-Io n
300
200
100
LeadA c id
N iCd
200 years
N iMH
0
0
50
100
150
200
250
300
350
S p ecific E n erg y (W h /kg )
Even a low efficient ICE will have a better
energy density and specific energy under
normal running conditions.
For the same rated power an electric vehicle
is much heavier than a ICE.
Cost of batteries!
Source: Tarascon and D. Foster Keynote speech at ASME ICES 2009
20
20
Electric Vehicle – Electricity source?
Q: What is the similarity of
a steam engine and a
battery electric vehicle?
A: They both run on coal…
21
www.cameco.com
Summary on alternatives
• They have all promised much but delivered
little!
• There is today not a viable alternative to the
Internal Combustion Engine
• We must focus our little resources to improve
what will be the prime mover of the future,
not unrealistic scenarios
• The ICE can be improved very much in the
future
22
Car of the future, today
• Smaller car with small ICE in combination with hybrid system. Fuel
consumption of 0.67-1 l/100km (<25 g/km CO2)
• ICE 60% fuel efficient with below zero levels of local emissions like
NOx, PM, HC and CO. The 40% heat loss is used for heating the car.
• At least 100% CO2-neutral with renewable fuel
Car of the future, in the future
Car of the future, the Crystal Ball?
German architect André Broessel of Rawlemon
Outline
• Introduction
• The future is hard to predict
• Options
• Other combustion engines?
• Fuel cells?
• Batteries?
• Combustion engines
• What is high efficiency?
• Combustion, thermodynamic, gas exchange and mechanical
efficiencies. All four must be high.
• What options do we have?
• Combustion to enable high efficiency
•
•
•
•
Spark Ignition
Compression Ignition
HCCI
Partially Premixed Combustion
• Can we do something about engine design?
• Conclusions
Energy flow in an IC engine

Brake

Combustion
*
Thermodyna mic
*
GasExchang e
FuelMEP
Combustion efficiency
QemisMEP
QhrMEP
QhtMEP
Thermodynamic efficiency
QlossMEP
QexhMEP
Gross Indicated efficiency
IMEPgross
Gas exchange efficiency
Net Indicated efficiency
lMEPnet
Mechanical efficiency
Brake efficiency
PMEP
BMEP
FMEP
*
Mechanical
+ Clean with 3-way
Catalyst
- Poor low & part load
efficiency
Combustion modes
Compression Ignition
(CI) engine (Diesel)
Spark Ignition (SI)
engine (Gasoline, Otto)
+ High efficiency
+ Ultra low NOx
Spark Assisted
Compression Ignition
(SACI)
Gasoline HCCI
+ High efficiency
- Emissions of NOx and
soot
Homogeneous Charge
Compression Ignition
(HCCI)
-Combustion control
-Power density
Partially premixed
combustion (PPC)
Diesel HCCI
+ Injection controlled
- Less emissions
advantage
ICE research in Lund vs. time
CCV=Cycle to Cycle
Variations in
Spark Ignition
Engines
GDI= Gasoline Direct
Injection
2-S= Two Stroke
engine
VVT=Variable Valve
Timing
HCCI=Homogeneous
Charge
Compression
Ignition
SACI=Spark Assisted
Compression
Ignition
PPC= Partially
Premixed
Combustion
1990
1995
2000
2005
2010
2015
29
Emission focus vs. time
1970
1980
1990
2000
2010
2020
30
HCCI -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
SAE2006-01-0205
31
All four efficiencies
SAE keynote Kyoto 2007
32
Net indicated efficiency= ηC ηT ηGE
SI std
SI high
+100%
HCCI
VCR
Scania
Brake efficiency
SI std
SI high
HCCI
VCR
Scania
Net indicated efficiency= ηC ηT ηGE
47%
SI std
SI high
HCCI
VCR
Scania
PPC - Diesel engine running on gasoline
HCCI: ηi=47% => PPC: ηi=57%
Group 3, 1300 [rpm]
60
Gross Indicated Efficiency [%]
55
50
FR47333CVX
FR47334CVX
FR47336CVX
45
40
35
30
25
20
0
2
4
6
8
Gross IMEP [bar]
10
12
14
36
Partially Premixed Combustion, PPC
Spridare 8x0.12x90 & 8x0.12x150, Iso-oktan, CR-tryck 750 bar, Duration 0,6 ms = 3.6 CAD
6000
1200
CI
HC [ppm]
5000
1000
PPC
4000
800
3000
600
2000
400
1000
200
-180
-160
-140
-120
-100
-80
SOI [ATDC]
-60
-40
NOx [ppm]
PCCI
HCCI
-20
Def: region between truly homogeneous combustion, HCCI,
and diffusion controlled combustion, diesel
SAE 2004-01-2990
37
Experimental setup, Scania D12
Bosch Common Rail
Prailmax
1600
[bar]
Orifices
8
[-]
Orifice Diameter
0.18
[mm]
Umbrella Angle
120
[deg]
15
[bar]
1951
[cm3]
2.9
[-]
Engine / Dyno Spec
BMEPmax
Vd
Swirl ratio
Fuel: Gasoline or Ethanol
38
SAE 2009-01-2668
38
Efficiencies 17.1:1
100
95
90
85
[%]
80
Combustion Efficiency
Thermal Efficiency
Gas Exchange Efficiency
Mechanical Efficiency
75
70
65
60
55
50
39
SAE 2009-01-2668
4
5
6
7
8
9
10
Gross IMEP [bar]
39
11
12
13
Efficiencies 14.3:1
100
95
90
85
[%]
80
Combustion Efficiency
Thermal Efficiency
Gas Exchange Efficiency
Mechanical Efficiency
75
70
65
60
55
50
40
SAE 2010-01-0871
4
6
8
10
12
Gross IMEP [bar]
40
14
16
18
Emissions
2
0.6
1.6
1.4
Smoke [FSN]
NOx [g/kWh]
0.4
Better tuned EGR-
combination
1.8
Gross
Net
Brake
EU VI
US 10
0.5
0.3
0.2
1.2
1
0.8
0.6
0.4
0.1
0.2
0
2
4
6
8
10
12
Gross IMEP [bar]
14
16
0
18
1.5
6
8
10
12
Gross IMEP [bar]
14
16
18
10
Gross
Net
Brake
EU VI
US 10
1.2
9
Gross
Net
Brake
EU VI
US 10
8
7
0.9
CO [g/kWh]
HC [g/kWh]
4
0.6
6
5
4
3
0.3
2
1
0
2
4
6
8
10
12
Gross IMEP [bar]
14
16
18
41
0
2
4
6
41
8
10
12
Gross IMEP [bar]
14
16
18
Emissions – different fuels
Ethanol
FR47330CVX
FR47331CVX
FR47333CVX
FR47334CVX
FR47335CVX
FR47336CVX
FR47338CVX
0.45
0.4
NOx [g/kWh]
0.35
0.3
2.5
Ethanol
FR47330CVX
FR47331CVX
FR47333CVX
FR47334CVX
FR47335CVX
FR47336CVX
FR47338CVX
2
Soot [FSN]
0.5
0.25
0.2
1.5
1
0.15
0.1
0.5
0.05
0
2
4
6
8
10
12
14
Gross IMEP [bar]
16
18
0
20
12
4
6
8
10
12
14
Gross IMEP [bar]
16
18
20
10
Ethanol
FR47330CVX
FR47331CVX
FR47333CVX
FR47334CVX
FR47335CVX
FR47336CVX
FR47338CVX
8
6
Ethanol
FR47330CVX
FR47331CVX
FR47333CVX
FR47334CVX
FR47335CVX
FR47336CVX
FR47338CVX
9
8
7
HC [g/kWh]
10
CO [g/kWh]
2
4
6
5
4
3
2
2
1
0
2
SAE 2010-01-0871
4
6
8
10
12
14
Gross IMEP [bar]
16
18
20
0
2
4
6
8
42
10
12
14
Gross IMEP [bar]
16
18
20
Tested Load Area
Stable operational load vs. fuel type
25
IMEP gross [bar]
20
15
10
5
0
20
30
40
50
60
RON [-]
43
70
80
90
100
43
Efficiency with Diesel or Gasoline
Average improvement of 16.6% points at high load by replacing diesel fuel with gasoline!
52
D13 Gasoline
D13 Diesel
50
Brake Efficiency [%]
48
46
44
42
40
38
36
34
5
10
15
20
Gross IMEP [bar]
25
30
D13 Diesel was calibrated by Scania to meet EU V legislation.
44
PPC Combustion Summary
• PPC has shown very high 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
• Emissions are below US10/Euro 6 without
aftertreatment for NOx, PM, HC and CO!
• The fuel properties are critical for PPC load
range
45
ICE research in Lund vs. time
CCV=Cycle to Cycle
Variations in
Spark Ignition
Engines
GDI= Gasoline Direct
Injection
2-S= Two Stroke
engine
VVT=Variable Valve
Timing
HCCI=Homogeneous
Charge
Compression
Ignition
SACI=Spark Assisted
Compression
Ignition
PPC= Partially
Premixed
Combustion
1990
1995
2000
2005
2010
2015
46
Energy flow in an IC engine

Brake
✔

Combustion
*
✔ ✖ ✖
Thermodyna mic
*
GasExchang e
FuelMEP
Combustion efficiency
QemisMEP
QhrMEP
QhtMEP
Thermodynamic efficiency
QlossMEP
QexhMEP
Gross Indicated efficiency
IMEPgross
Gas exchange efficiency
Net Indicated efficiency
lMEPnet
Mechanical efficiency
Brake efficiency
PMEP
BMEP
FMEP
*
Mechanical
High efficiency thermodynamics:
Simulation results from GT-power
• Indicated efficiency 64%
• Brake efficiency 60.4%
• System layout is confidential
Outline
• Introduction
• The future is hard to predict
• Options
• Other combustion engines?
• Fuel cells?
• Batteries?
• Combustion engines
• What is high efficiency?
• Combustion, thermodynamic, gas exchange and mechanical
efficiencies. All four must be high.
• What options do we have?
• Combustion to enable high efficiency
•
•
•
•
Spark Ignition
Compression Ignition
HCCI
Partially Premixed Combustion
• Can we do something about engine design?
• Conclusions
The future ICE
• Highest possible fuel efficiency
• Low enough emissions of NOx, PM, HC, CO
• Capable of using renewable fuels
And the basic requirements of all products:
•
•
•
•
•
Very high durability
Low service requirements
High power/mass ratio
High power/volume ratio
Low cost
50
Future
• Optimize the combustion process
– PPC
– Diesel
– Spark Ignition (prechamber)
1
• Improve the thermodynamics
hT = 1- g -1
– A compression ratio,Rc of 70:1 and lean mixture Rc
(γ=1.38) gives a thermodynamic efficiency
of 80%!
• Work with engine systems, not only details
51
What is the long term future?
• Active rate shaping
– What is the best Rate of Heat Release, RoHR, for maximum thermodynamic
efficiency?
– The analog fuel injector with real time control of fuel flow and hence RoHR (with
short ignition delay) using FPGA
• Fuels and engine interactions
– Best fuel for a combustion process
– Fuel flexible combustion process
• Natural gas/Biogas
– LNG/LBG-intercooler
• Hybrids
– The 2, 4, 6 concept
– Air Hybrid
• Heat transfer, coatings etc.
52
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
Lund University
Thank you!
54
High Efficiency Combustion
Engines – What is the limit?
Prof. Bengt Johansson
Lund University

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