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Eaton EGR Pump Value Proposition
Nilesh L. BagalNov. 4 2019
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Outline
• Background
• Base Model Development
• EGR Pump Analysis
• Air System changes
• Engine system optimization
• Summary
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Background
• EGR Pump can be used to drive external EGR, enabling the use of a
fixed geometry turbine (FGT) in engines
• EGR pump enables decoupling of EGR from turbo which can drive
turbo matching for air system requirement
• The aim of this study is to understand the EGR Pump value
proposition for both EATON and engine/vehicle OEM’s
• This study is intended to help customers assess EGR pump viability
with current production hardware or new engine architectures
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Diesel EGR PumpSaving fuel while meeting new emissions regulations
High-efficiency turbo Reduced engine pumping work Better fuel econ
Improved EGR and boost system
architecture: 1. Add EGR Pump to drive EGR
2. Delete EGR valve.
3. Optimize turbo for high-efficiency
boosting (replace VGT with FGT)
EGR Pump Value • Fuel economy
• Full-authority EGR rate control
• Deletion of some expensive
components
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Analytical Evaluation of EGR Pump
• An analytical evaluation of the EGR pump value proposition is performed using a GT-POWER engine model. Key steps are:
• Base model development:
• Develop model representing current production HD diesel engine with VGT
• Calibrate and validate model using measured data
• Implement EGR pump and evaluate fuel benefits:
• Implement latest EGR pump configuration
• Assess fuel consumption improvement using optimized air system (FGT) and engine calibration
* Complete benefit evaluation
requires hardware testing
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Base Model Development, Calibration and
Validation with Measured Data
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Base Model Development
❖ Well calibrated and validated base model is the key
• Developed representative HD diesel engine model with VGT
• Model represents a state of the art current production HD diesel engine
• Engine: 13L, 6 cylinder, single stage VGT
• Model is calibrated to match SwRI CHEDE test data
• Close to production calibration data is used
• Performance data for 13 mode European Stationary Cycle (ESC) operating condition from SwRI
• Model is validated using with EGR sweep data
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BTE & BSFC – Measured Data
BTE and BSFC values represent a efficient current production HD engine
BTE & BSFC – Measured Data
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Base GT-POWER Engine Model
VGT
EGR Loop
Intake Exhaust
Cylinders
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Model Result Comparison – Calibration Data
BTE (%) BSFC (g/kW-hr)
Model results compare well with lab data (< 3% max. error)
Measured Data
Mo
del R
esu
lt
Measured Data
Mo
del R
esu
lt
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Model Result Comparison – Calibration Data
EGR (%) BNOx (g/kW-hr)
Model results compare well with lab data
Measured Data
Mo
del R
esu
lt
Measured Data
Mo
del R
esu
lt
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1200 rpm Full Load 1800 rpm Full Load
Model results compare well with lab data
Crank Angle
Pre
ssu
re (
bar)
Pre
ssu
re (
bar)
Cylinder Pressure Comparison
Crank Angle
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Evaluation of EGR Pump Fuel
Improvements using Engine Model
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EGR Pump as EGR Driver System optimization
using EGR pump
Intercooler
EG
R C
oo
ler
Crank
PIntake
PExhaust
48V Power
1
3
24
EGR Pump
1. VG to FG turbine reduces pumping work
2. Exhaust design changes to improve
turbine efficiency
3. Combustion & Calibration optimization
4. Aftertreatment optimization
Pintake > Pexhaust
(pumping benefit)
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Air System & Design Optimization
• Turbo matching is performed to provide required boost at peak torque and maintain low speed torque capability
• VGT Wastegate FGT
• Overall turbine efficiency improvement is predicted, moving from VGT (~ 69%) to optimized FGT (~ 75%) for A100 operating condition
• VGT Twin scroll FGT and split exhaust manifold
• Single log exhaust manifold is modified to split exhaust to account for high pulse energy
• Overall turbine efficiency improvement is predicted, moving from VGT (~ 69%) to optimized FGT (~ 87%) for A100 operating condition
• TVS 400cc EGR pump is implemented downstream of EGR cooler
• Engine out NOx levels are maintained
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GT-POWER Engine Model with FGT
FGT
EGR Loop
Intake Exhaust
EGR Pump
Cylinders
Turbo Matching Object
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Turbo Efficiency Comparison
❖ SwRI Data
• Single stage FGT GT45 turbo, split
exhaust manifold
Comp = 77%, Turb = 83%
❖ Eaton EGR Pump Analysis
• Single stage FGT with WG, open exhaust
manifold
Comp = 70%, Turb = 75%
• Twin scroll FGT with WG, split exhaust
manifold
Comp = 70%, Turb = 87%
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BSFC % Improvement for 13 Mode ESC
1.8
3.4
3.1
3.5
1.7
2.5
2.7
4.34.6
3.6
2.4
2.40
1.2
0.6
0.5
0.4
1.2
1.5
2.4
2
1.7
0.7
0.7
Based on 13 Mode ESC Cycle Weightage, Model Predicts 1.15 and 3.1 % Fuel Benefit
Bubble size indicate
weightage at each mode
Bra
ke T
orq
ue (
N-m
)
Engine Speed (rpm)
Bra
ke T
orq
ue
(N
-m)
Engine Speed (rpm)
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Engine System Optimization (CR, SOI,
EGR% and Miller Cycle)
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Engine Optimization
• Evaluated engine calibration, Compression Ratio (CR) and Miller cycle sensitivity to further improve engine fuel efficiency for twin scroll architecture
• DOE’s were run for SOI, EGR%, CR and different LIVC cycles for all 12 modes
• Performance optimization:
• CR increased by 2
• IVC retarded by 30 crank deg.
• EGR and SOI optimized for each speed load operation
• Constraints:
• Meet base engine out BSNOx
• Peak cylinder pressure <250 bar
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Engine Optimization
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BSFC % Improvement
BSFC improvement up to 6.2 % is predicted.
Bra
ke T
orq
ue (
N-m
)
Engine Speed (rpm)
2.9
4.5
4.9
5.3
2.5
3.5
3.7
6.2
4.7
3.8
3.4
5.5
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BTE Improvement
Base Optimized Engine with EGR Pump
Bra
ke T
orq
ue (
N-m
)
Engine Speed (rpm)
Bra
ke T
orq
ue (
N-m
)
45
45
43
39
45
44
43
38
44
43
41
36
45
44
42
37
46
46
44
40
47
45
44
39
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Summary
• Well calibrated GT-POWER engine model is used to analytically evaluate
fuel consumption benefit of EGR pump.
• Two different turbo configurations (FGT and twin scroll) are evaluated by
replacing VGT to improve engine pumping losses.
• ~ 2.5% fuel consumption benefit predicted when converting from VGT to
FGT with EGR pump.
• ~ 5% fuel consumption benefit predicted when converting from VGT to twin
scroll FGT with EGR pump.
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Summary
• Engine system and calibration optimization is performed.
• Optimized engine with EGR pump, single stage twin scroll FGT with
wastegate and split exhaust manifold design model predicts up to 6.2% fuel
consumption benefit.
• Based on drive cycle weighting, model predicts 1 – 4 % fuel benefit for 13
mode ESC engine dyno cycle.
• GT-POWER is a good tool to analytically evaluate performance. GT example
models provide a good representative base model.
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Acknowledgement
• Southwest Research Institute (SwRI)
• Gamma Technologies
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