Future Passenger Car R2S Ch i S t i VTGCharging Systems - using VTG and Low Pressure EGR?
GT-SUITE Conference 2008
Dr Frank SchmittDr. Frank Schmitt
Sebastian Howe
Philipp Wilkens
October 20, 2008
Contents
• Status on Regulated 2-Stage (R2S) Charging System
• Comparison of engine performance and fuel consumption of R2S System vs. VTG (Downsizing)
• Use of Variable Turbine Geometry in R2S Applications
• High Pressure EGR vs. Low Pressure EGR
• ConclusionsConclusions
Product Development Calculations and SimulationsDr. Frank Schmitt
2
Status in R2S™ - Regulated-2-Stage
EGR Valve
EGR Cooler
Charge Air Cooler
Regulating Valve
HP stage TurbineCompressor HP stage Turbo-gCompressor Bypass
HP stage Turbocharger
LP stage Turbo-charger with Bypass
Product Development Calculations and SimulationsDr. Frank Schmitt
3
R2S™ : Compressor Map
Overall pressure ratio
Product Development Calculations and SimulationsDr. Frank Schmitt
R2S™ - 2.0 L Passenger Car Application
Comparison of engine performance and fuel p g pconsumption
2 7L V6 Diesel with Mono VTG versus 2 0L Diesel I42.7L V6 Diesel with Mono VTG versus 2.0L Diesel I4 with Two Stage System R2S
Product Development Calculations and SimulationsDr. Frank Schmitt
5
Downsizing: R2S 2.0 L vs. VTG 2.7 L
Power
120
140
160
80
100
wer
[kW
]
VTG 2 7 L
20
40
60Pow VTG 2.7 L
R2S 2.0 L
0
20
0 1000 2000 3000 4000 5000 6000
engine speed [rpm]
Product Development Calculations and SimulationsDr. Frank Schmitt
6
engine speed [rpm]
Downsizing: R2S 2.0 L vs. VTG 2.7 L
Brake spec. Fuel consumption
270
280
290
g/kW
h] VTG 2.7 L
240
250
260
nsum
ptio
n [g R2S 2.0 L
210
220
230
spec
. fue
l con
200
210
0 1000 2000 3000 4000 5000 6000
engine speed [rpm]
s
Product Development Calculations and SimulationsDr. Frank Schmitt
7
engine speed [rpm]
VTG in R2S Applications
R2S™ Charging Systems with Variable Turbine Geometry:Geometry:
Driver:• Emission Concept to fulfill future Emission Legislation• Higher EGR rates• Higher Air-Fuel Ratio• Higher Air-Fuel Ratio• Fuel Consumption
Product Development Calculations and SimulationsDr. Frank Schmitt
8
VTG in R2S Applications
30
200 220 N /L
20
25
bar]
70-100 kW/L
200-220 Nm/L
150-180 Nm/LR2S with VTG
2-stage
1 stage15bm
ep [b
VTGSerial Sequential (R2S)
50-70 kW/L50-70 kW/L
1-stage
5
10
0 1000 2000 3000 4000 5000
q ( )Fixed Geometry Turbine (FGT)Parallel SequentialSerial Sequential (R2S) w ith VTG
0 1000 2000 3000 4000 5000
engine speed [rpm]
Product Development Calculations and SimulationsDr. Frank Schmitt
9
R2S Charging Systems
VTG in High Pressure Stage
or
VTG in Low Pressure Stage:
Product Development Calculations and SimulationsDr. Frank Schmitt
10
R2S Charging Systems: Variable Turbine in HP-Stage
BV40 Mass FLowChart
KP39 Mass Flow
improved transition 1-stage ↔ 2-stagereduced Pressure p3 → improved be
High Pressure Stage: Fix Geometry Turbine + Bypass
340 390
80%
430 /
210
280 340max.
u r edT = 390 m/ s1.2
1.4
1.6
kg/s
*√K
/KP
a*10
2 ]
1.2
1.4
1.6
kg/s
*√K
/KP
a*10
2 ]
therm.-min.211
281340
20%
u r edT = 390 m/ s
140
210
280
340389
40%
u r edT = 430 m/ s
140
210
280
340390
60%
u r edT = 430 m/ s
140
210
280u r edT = 430 m/ s
140
0.6
0.8
1.0
turb
ine
flow
par
amet
er [
210
280
340
390u r edT = 430 m/ s
KP39-240.82ACAAD, 017231vt1
0.6
0.8
1.0
turb
ine
flow
par
amet
er [k
test-no. 024795t1 024796t1 024797t1 024798t1 024799t1 024800t1 024801t1 resp. date d5
symbol X WSV 08.02.06 38.5testdate 06.02.2006 01.02.2006 02.02.2006 03.02.2006 03.02.2006 03.02.2006 02.02.2006turbine 340.18 AVAXK 340.18 AVAXK 340.18 AVAXK 340.18 AVAXK 340.18 AVAXK 340.18 AVAXK 340.18 AVAXK
sh & h ass 5439 120 8501/1 5439 120 8501/1 5439 120 8501/1 5439 120 8501/1 5439 120 8501/1 5439 120 8501/1 5439 120 8501/1
340.18 AVAXK
170 220 260
mech.-min.
u r edT = 310 m/ s
140210
280u r edT = 340 m/ s
141
0.2
0.4
1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00expansion ratio p3t/p4 [-]
test-no. 017230vt1 017231vt1 017232vt1 021419t1 resp. date d5
symbol X SFR 03.11.06 38.5testdate 27.01.2004 28.01.2004 27.01.2004 19.02.2005turbine 200.82 ACAAD 240.82 ACAAD 280.82 ACAAD 310.12 ACCXK XXX.8X ACAAD
140
0.2
0.4
1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00
expansion ratio p3t/p4 [-]
sh & w h assy 5439 120 8501/1 5439 120 8501/1 5439 120 8501/1 5439 120 8501/1 5439 120 8501/1 5439 120 8501/1 5439 120 8501/1
hous. mach. 5440 910 7801/1 5440 910 7801/1 5440 910 7801/1 5440 910 7801/1 5440 910 7801/1 5440 910 7801/1 5440 910 7801/1BV40sh & w h assy 5439 120 5008/2 5439 120 5008/2 5439 120 5008/2 5439 120 5013/1
hous. mach. 5439 910 8003/1 5439 910 8004/1 5439 910 8005/1 5439 101 6302/1KP39
improved Low End Torqueimproved Part Load (EGR, AFR)
Product Development Calculations and SimulationsDr. Frank Schmitt
11
R2S Charging Systems: Variable Turbine in LP-Stage
Chart
Low Pressure Stage: Fix Geometry Turbine
Low Pressure Stage: VTG
340390
100%, 031435t1
uredT = 430 m/s 80%, 031441t1
2.2
2.6
3.0
kg/s
*√K
/KP
a*10
2 ]
2.2
2.6
3.0
kg/s
*√K/
KPa*
102 ]
140
210
280
140
210
280
340
390uredT = 430 m/s
140
210
280
340
389
60%, 031440t1
uredT = 431 m/s
210
280
340390
40%, 031439t1
uredT = 430 m/s
280
340 391
20%, 031438t1
uredT = 431 m/s
Thermodyn Min 031436t1
1.0
1.4
1.8
turb
ine
flow
par
amet
er [
140
210
280
340
390
023767t1
uredT = 430 m/s
1.0
1.4
1.8
turb
ine
flow
par
amet
er [k
test-no. 031435t1 031441t1 031440t1 031439t1 031438t1 031436t1 031437t1 resp. date d5
symbol X SFR 18.09.07 50testdate 12.09.2007 14.09.2007 14.09.2007 14.09.2007 13.09.2007 12.09.2007 13.09.2007turbine 380.18 BVAXK 380.18 BVAXK 380.18 BVAXK 380.18 BVAXK 380.18 BVAXK 380.18 BVAXK 380.18 BVAXK
380.18 P9VAXK
140
141
210
140140
210210281
Thermodyn. Min, 031436t1
uredT = 340 m/s
140 210
Min, 031437t1
uredT = 280 m/s
0.2
0.6
1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00
expansion ratio p3t/p4 [-]
test-no. Tref [K] responsible date drawing number remark023767t1 873 SCG 01.08.2006
250.88 AAAXKA0 = 6.53cm²
0.2
0.6
1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0
expansion ratio p3t/p4 [-]
sh & wh assy 1850 912 5003/1 1850 912 5003/1 1850 912 5003/1 1850 912 5003/1 1850 912 5003/1 1850 912 5003/1 1850 912 5003/1
hous. mach. 1850 910 7802/1 1850 910 7802/1 1850 910 7802/1 1850 910 7802/1 1850 910 7802/1 1850 910 7802/1 1850 910 7802/1BV50
closed VTG to improve transition 1-stage ↔ 2-stage
wheel casting shaft&wheel assy. turb. hsg. cast. turb. hsg. mach. compressor d5 [mm] d6 [mm] b5 [mm] clearance [mm]5316 912 3199 5316 912 5016/1 5316 910 6364 5316 910 6203/1 2471 OYCKB 0.053 0.0472 0.00678 0.00051
K16
Product Development Calculations and SimulationsDr. Frank Schmitt
12
R2S™ - 2.0 L PassCar-Application
Engine Performance Simulationg
2.0L Diesel I4 with Two Stage System R2S with 2 Fix Geometry T/CTwo Stage System R2S with 2 Fix Geometry T/C compared to R2S with Variable Turbine Geometry in HP or LP Stage
Product Development Calculations and SimulationsDr. Frank Schmitt
13
GT-Power Model - 2.0 L Diesel Engine
Engine Data:
Di l t 2 0 LDisplacement 2.0 L
Rated Power 150 kW
Max. Torque 400 Nm
Product Development Calculations and SimulationsDr. Frank Schmitt
14
GT-Power Model - 2.0 L Engine
HP StageHP Stage
LP Stageg
Product Development Calculations and SimulationsDr. Frank Schmitt
15
GT-Power Model - 2.0 L Engine
Torque Boost Pressure
Test DataTest Data
SimulationSimulation
Good Match of Engine Simulation Data vs Test Data
Product Development Calculations and SimulationsDr. Frank Schmitt
16
Good Match of Engine Simulation Data vs. Test Data
GT-Power Model – Turbo Charger Variations
Compressor Turbine
R2S® (Basis)HP 1672C (41 mm) KP35-180.12 A (35 mm)
LP 2471N (62 mm) K16-250.88 A (53 mm)
R2S® with HP 1672C (41 mm) BV38-340.10 P1 (37.5 mm)R2S® with HP VTG LP 2471N (62 mm) K16-250.88 A (53 mm)
R2S® with LP VTG
HP 1672C (41 mm) KP35-240.82 A (35 mm)
LP 2471N (62 mm) BV50-380.18 P9 (50 mm)
Product Development Calculations and SimulationsDr. Frank Schmitt
17
( ) ( )
GT-Power Results – Stationary, Full Load
R2S® Basis
R2S® i h Hi h
Power
R2S® with High Pressure Stage VTG
R2S® with LowPressure Stage VTG
Same EngineSame Torque / Power
Product Development Calculations and SimulationsDr. Frank Schmitt
18
GT-Power Results – Stationary, Full Load
bsfc
R2S® BasisR2S® Basis
R2S® with High Pressure Stage VTG
R2S® with LowPressure Stage VTG
Same EngineSame Torque / Power
R2S® with High Pressure Stage VTG shows best bsfcProduct Development Calculations and SimulationsDr. Frank Schmitt
19
R2S® with High Pressure Stage VTG shows best bsfc
GT-Power Results – Stationary, Full Load
Pressure p3 Turbine Efficiency
R2S® Basis R2S® with High Pressure Stage VTG
R2S® with High
R2S® with LowPressure Stage VTG
R2S® B i
R2S® with LowPressure Stage VTG
gPressure Stage VTG R2S® Basis
R2S® with High Pressure Stage VTG shows lowest p3
Product Development Calculations and SimulationsDr. Frank Schmitt
20at low Engine Speed due to best Turbine Efficiency
GT-Power Results – Part Load 1500 rpm / 4 bar
1500/4bar
238 5 1.76 1.77 1 76
245.00 1.80
238.5
234.9235.41.76
225.00
230.00
235.00
240.00
kWh]
1.70
1.75
da bsfc
210.00
215.00
220.00
bsfc
[g/k
1 55
1.60
1.65
Lam
b bsfcLambda
200.00
205.00
2WG HDVTG NDVTG1.50
1.55
Basis HP-VTG LP-VTG
Air-Fuel-Ratio (lambda/14.5) level constant
Benefits in bsfc for VTG in HP and LP Stage
R2S® with Low Pressure Stage VTG shows best bsfcProduct Development Calculations and SimulationsDr. Frank Schmitt
21
R2S® with Low Pressure Stage VTG shows best bsfc
GT-Power Results – Part Load 2000 rpm / 2 bar
2000/2bar
327.63 65 3.71
3 62
330.00 4.00
317.1
3.65 3.62
320.00
325.00
kWh] 3.00
3.50
bda
bsfc
306.4
305.00
310.00
315.00
bsfc
[g/
2.00
2.50 Lam
b bsfcLambda
300.002WG HDVTG NDVTG
1.50
Basis HP-VTG LP-VTG
Air-Fuel-Ratio (lambda/14.5) level constant
Benefits in bsfc for VTG in HP and LP Stage
R2S® with High Pressure Stage VTG shows best bsfcProduct Development Calculations and SimulationsDr. Frank Schmitt
22
R2S® with High Pressure Stage VTG shows best bsfc
GT-Power Results – Part Load 2000 rpm / 8 bar
2000/8bar
230.00 2.10
217.00
220.2
223.61.95
2.00 2.00
220.00
225.00
kWh]
1.90
2.00
da bsfc
205 00
210.00
215.00
bsfc
[g/k
1 60
1.70
1.80
Lam
bd bsfcLambda
200.00
205.00
2WG HDVTG NDVTG1.50
1.60
Basis HP-VTG LP-VTG
Air-Fuel-Ratio (lambda/14.5) level constant
Benefits in bsfc for VTG in HP and LP Stage
R2S® with Low Pressure Stage VTG shows best bsfcProduct Development Calculations and SimulationsDr. Frank Schmitt
23
R2S® with Low Pressure Stage VTG shows best bsfc
GT-Power Results – Part Load 2000 rpm / 8 bar
2000/8bar
3.00
2.632.51
2.352.50
[bar
]
2S
1.79 1.80 1.77
2.00pres
sure
p2Sp3 HDT
1.502WG HDVTG NDVTGBasis HP-VTG LP-VTG
p3, Pressure at Turbine inletP2, boost pressure
R2S® with Low Pressure Stage VTG shows lowest p3Product Development Calculations and SimulationsDr. Frank Schmitt
24
R2S® with Low Pressure Stage VTG shows lowest p3
GT-Power Results – Transient 40 – 80 km/h
R2S® Basis
R2S® i h Hi hR2S® with High Pressure Stage VTG
R2S® with LowR2S® with Low
Pressure Stage VTG
R2S® Basis
Pressure Stage VTG
R2S® with High Pressure Stage VTG
1 sec R2S® Basis~1 sec
R2S® with High Pressure Stage VTG shows
Product Development Calculations and SimulationsDr. Frank Schmitt
25best transient from 40 to 80 km/h
GT-Power Results – Transient 40 – 80 km/h
R2S® Basis
R2S® i h Hi hR2S® with High Pressure Stage VTG
R2S® with LowR2S® with LowPressure Stage VTG
Pressure Stage VTGR2S® with High Pressure Stage VTG
R2S® Basis
R2S® with High Pressure Stage VTG shows
Product Development Calculations and SimulationsDr. Frank Schmitt
26best boost pressure increase
Conclusions VTG in R2S Applications
• R2S became State of the Art Turbocharger System
• R2S Charging System shows benefit in FuelConsumption (Downsizing)
• Use of VTG in R2S systems shows high potential for - improved Fuel Consumption- higher Air-Fuel-Ratio- higher Air-Fuel-Ratio - higher EGR rates
Product Development Calculations and SimulationsDr. Frank Schmitt
27
Conclusions VTG in R2S Applications
• Variable Turbine Geometry in High Pressure Stage shows best results in bsfc at Full Load up to 3000 rpm, Part Load 2000 rpm / 2 bar and Transient ResponsePart Load 2000 rpm / 2 bar and Transient Response
• Variable Turbine Geometry in Low Pressure Stage shows best results in bsfc at Part Load 1500 rpm / 4 barshows best results in bsfc at Part Load 1500 rpm / 4 bar and 2000 rpm / 8 bar
• Use of VTG in High Pressure Stage or Low PressureUse of VTG in High Pressure Stage or Low Pressure Stage depends on:
- Package (VTG rather in HP Stage for Large Engines)E i T t (b f t i t)- Engine Targets (bsfc vs. transient)
Product Development Calculations and SimulationsDr. Frank Schmitt
28
R2S™ - 2.0 L PassCar-Application
Engine Performance Simulationg
High pressure EGR versus Low pressure EGR applied on a 2L turbocharged Engineon a 2L turbocharged Engine
Product Development Calculations and SimulationsDr. Frank Schmitt
29
Engine Model of 2L Engine
Tu
Engine Data:
Displacement: 2.0 Lurbocharge
p
Power: 100 kWr
m
Torque: 320 Nm
GR
–S
yste
m
Engine block
HP
EG
Product Development Calculations and SimulationsDr. Frank Schmitt
30
Match of Simulation Data vs. Test Data
Product Development Calculations and SimulationsDr. Frank Schmitt
31
Match of Simulation Data vs. Test Data
Product Development Calculations and SimulationsDr. Frank Schmitt
32
EGR-System: High Pressure EGR
fresh air manifold
EGR throttle
R-S
yste
m
exhaust manifold
HP-
EGR
EGR
coo
ler
Product Development Calculations and SimulationsDr. Frank Schmitt
33
EGR-System: Low Pressure EGR
fresh air manifold
Alternative the throttle can be appoint on this position
EGR throttle
m
oole
r
-EG
R-S
yste
EGR
co
LPexhaust manifold
Product Development Calculations and SimulationsDr. Frank Schmitt
34Additional Throttle togenerate a back pressure
Part load data points: Lambda (AFR / Lst)
part load data points
24Full load data curve
16
20
part load data points
12
16
bmep
[bar
]
λ=1.40
λ=1.65λ=1.65
λ=1.68
λ=1.60
λ=1.77
4
8 λ=1.71
λ=1.54 λ=1.72 λ=1.93 λ=2.24
λ=1.65 λ=1.62 λ=1.87
λ=1.62
λ=2.10
λ=1.72
0
4
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000i d [1/ i ]
λ=2.12 λ=2.40 λ=3.00 λ=3.07
Product Development Calculations and SimulationsDr. Frank Schmitt
35
engine speed [1/min]
Part load data points: Lambda (AFR / Lst)
Product Development Calculations and SimulationsDr. Frank Schmitt
36
Results: Maximum EGR-Rates
HP-EGR engine map LP-EGR engine map
40
50
60
%]
50-60
40-50
40
50
60
%]
50-60
40-50
20
30
40
EGR
-Rat
e [% 30-40
20-30
10-2020
30
40
EGR
-Rat
e [% 30-40
20-30
10-20
24
56
810
10002000
0
10
bmep in]
0-102
45
68
10
10002000
0
10
bmep [ba ] in]
0-10
1012
1518
20003000
3400
mep [bar]
engine speed [1/min] 1012
1518
3000
3400
[bar]
engine speed [1/min]
Product Development Calculations and SimulationsDr. Frank Schmitt
37Maximum EGR Rates
Results: Maximum EGR-Rates
BSFC engine speed HP-EGR BSFC engine map LP-EGR
300
350
400
450
300
350
400
450400-450
350-400
300-350
250 300
150
200
250
300
BSFC
[g/k
Wh]
150
200
250
300
BSF
C [g
/kW
h] 250-300
200-250
150-200
100-150
50 100
24
56
810
10001500
2000
0
50
100
bmep [bar]n]
24
56
810
12
10001500
2000
0
50
100
bmep [bar][1/min]
50-100
0-50
1215
20002500
3000engine speed [1/min] 12
152000
25003000 engine speed [1/m
Product Development Calculations and SimulationsDr. Frank Schmitt
38Specific fuel consumption BSFC
Results: Trade off EGR-Rates - BSFC
16
Difference EGR-rate (LP-EGR - HP-EGR)
50
Difference BSFC (LP-EGR - HP-EGR)
8
10
12
14
16
ate
[%]
14-1612-1410-128-106-8
30
40
50
[g/k
Wh]
40-50
30-40
20-30
0
2
4
6
8
Δ E
GR
-Ra
4-62-40-2-2-0 0
10
20
Δ B
SFC
[ 10-20
0-10
-10-0
2 4 5 6 810 12
1518
1000
1500
2000
2500
3000
500
0
-2
0
bmep [bar] e spe..
2 4 56
810
1215
18
00 1500 20
00 2500 30
00 3500
-10
bmep [bar]e spe..
35
400
]
engine s
100 1
engine s
Product Development Calculations and SimulationsDr. Frank Schmitt
39Specific fuel consumption BSFC
Conclusions HP-EGR vs. LP-EGR
• Low Pressure EGR System allows higher EGR-rates
• Additional Measures on the EGR System:• Throttle (before Compressor or after Turbine
to increase pressure drop)to increase pressure drop)• Protection of Compressor (Wheel, Housing)
• increased Fuel Consumptionincreased Fuel Consumption
Product Development Calculations and SimulationsDr. Frank Schmitt
40
Final Remark
Decision on final R2S system layout based on furtherDecision on final R2S system layout based on further Investigations in transient test cycles
Additi l I ti ti ith R2S d L P EGRAdditional Investigations with R2S and Low Pressure EGR
A Combination of R2S with Variable Turbine Geometry yand Low Pressure EGR shows: • a high Potential to reduce Fuel Consumption• a high Potential to fulfill Future Emission Legislation• a high Potential to fulfill Future Emission Legislation
Product Development Calculations and SimulationsDr. Frank Schmitt
41