Transcript
Lambda 1 High Load Operation via Water Injection Sam Barros Director of Research and Development Nostrum Energy, LLC
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
1
Outline • Motivation • Experimental Setup ⁃ Engine Setup ⁃ Water Injection ⁃ Controls
• Simulation • Experimental Results • Conclusions • Next Steps Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
2
Motivation • Avoiding this! • Enabling the next generation of high efficiency engines
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
3
Motivation • Despite increasing popularity, engine “downsizing” does not delivery dramatic real-world fuel economy benefits. • Downsized engines must be operated at higher loads, often into regions where spark retard and/or over fueling is used to control knock. • Maximum engine output in SI engines is limited by knock (auto-ignition)
• Mitigation of knock is an enabler for aggressive downsizing AND increased performance Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
4
Experimental Setup Baseline Engine
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
• • • •
SIDI 2.0L GM Ecotec LTG Twin Scroll Turbocharger Dual Independent Cam Phasing Large Aftermarket Support
5
Experimental Setup – Water Injection • Injectors installed in intake manifold
Water Rail
Injector with Bosses welded to manifold
• Direct Injection also an option
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
6
Experimental Setup – Water Injection • Test water is generated through Reverse Osmosis • High Pressure supply (250 bar) for Direct Injection testing • Low Pressure supply (10 bar) for Port Injection testing • Flow measured with Coriolis meter
Reverse Osmosis Filtration System
Building Water Supply
Drain to Sewer System High Pressure Pump
RO Water Reservoir
12V Signal I/O Air Supply ~110psi
Data Acquisition System
PWI Water Tank
Air Supply ~200psi
Flow Metering Device
Port Injection Controller
Temperature and Pressure Transducers
Filter
Direct Injection Controller
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
Temperature and Pressure Transducers
Vent to Atmosphere
Port Injectors
Engine
Intake Manifold
Direct Injectors
Engine
Exhaust System
Exhaust System
7
Experimental Tests To Be Discussed Fuel
Water Injection
Spark Timing / Combustion Phasing
I-Cam
E-Cam
Lambda
Test 1
91 AKI (Engine manufacturer req.)
None
Production
Production
Production
Production
Test 2
110 AKI
None
10° CA50 or KLSA*
Production
Production
Production
Test 3
87 AKI
Port Injection
10° CA50 or KLSA*
Production
Production
1.0
Test Number
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
8
Experimental Results: Combustion Combustion Phasing
Burn Duration
Baseline Engine
Baseline Engine
30
45 40
25
35 30
BD10-90
CA50 (°ATDC)
20
15
10
25 20 15
MBT
10 5
CA50 EA; 91 AKI, Baseline
BD10-90_EA; 91 AKI, Baseline
5
CA50 EA; 110 AKI, MBT / KLSA
BD10-90_EA; 110 AKI, MBT / KLSA
CA50 EA; 87 AKI, MBT / KLSA, Lambda 1
0 1500
2000
2500
3000
3500
4000
4500
5000
Engine Speed (RPM)
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
BD10-90_EA; 87 AKI, MBT / KLSA, Lambda 1
5500
0 1500
2000
2500
3000
3500
4000
4500
5000
5500
Engine Speed (RPM)
9
Experimental Results; Output Mean Effective Pressure Baseline Engine
35
NET MEP (bar)
30
25
20
15
10 NMEP EA; 91 AKI, Baseline
5
NMEP EA; 110 AKI, MBT / KLSA NMEP EA; 87 AKI, MBT / KLSA, Lambda 1
0 1500
2000
2500
3000
3500
4000
4500
5000
5500
Engine Speed (RPM)
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
10
Experimental Results; Efficiency Net Thermal Efficiency Baseline Engine
40
NET Thermal Efficiency (%)
35 30 25 20 15 10 Net Thermal Efficiency; 91 AKI, Baseline
5
Net Thermal Efficiency; 110 AKI, MBT / KLSA Net Thermal Efficiency; 87 AKI, MBT / KLSA, Lambda 1
0 1500
2000
2500
3000
3500
4000
4500
5000
5500
Engine Speed (RPM) Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
11
Experimental Results: Exhaust Gas Temperatures
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
12
Simulation • 1D Engine Simulation was utilized to scope the High BMEP Build (Target 50 bar BMEP) ⁃ Determination of required air pressure and flow ⁃ Investigation of peak cylinder pressure over a range of compression ratios ⁃ The same simulation model will be used to evaluate the impact of water injection
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
13
Simulation Results • Fuel Enrichment and Combustion Phasing both have large impact on Net Thermal Efficiency • Good opportunity for efficiency improvements
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
14
Simulation Results Airflow and Pressure Requirement Over a Range of Lambda and Compression Ratio (3000 RPM, 50 bar BMEP)
• Required P/R and mass flow are challenging for a single compressor
5 4.75
Pressure Ratio (:)
4.5
• Boost pressure is currently supplied via an external compressor
4.25 4
• Good candidate for alternative boosting systems (multi-stage, compounded)
3.75 3.5 3.25 3
700
750
800
850
900
950
Airflow (kg/hr)
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
15
Simulation Results Impact of Compression Ratio on Unburned Gas Temperature (3000 RPM, 50 bar BMEP) 1000
A/F = 12.0 CA50 = 10° ATDC
Unburned Gas Temperature (K)
900 800 700 600 500
CR = 9.2:1
400
CR = 10.0:1 CR = 11.0:1
300
CR = 12.0:1 Auto-Ignition Temperature; Iso-Octane
200
-75
-55
-35
-15
5
25
45
65
85
105
125
Theta (Crank Angle)
11.0:1 chosen as a compromise between efficiency, peak cylinder pressure, and unburned gas temperature (knock propensity) Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
16
Water Injectors • Patented jet-to-jet collision breakup mechanism • Reduced spray penetration and improved liquid atomization allow faster water vaporization rates 5/26/2016
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
17
Water Injectors used on this project • Spray Targeted Nostrum KiWi; Kinetic Water Injector
• Nostrum Water DI injector (next phase)
5/26/2016
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
18
PFI Spray Targeting – Symmetric Spray Intake port impingement due to wider, non targeted-symmetric spray plume
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
19
PFI Spray Targeting – Directional Spray Intake port impingement avoided significantly by a narrower, directional spray plume targeted to the back of the intake valve
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
20
PFI Spray Targeting – Directional Spray Movie
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
21
Liner & Piston Impingement
Fuel impingement on the liner due to improper spray targeting Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
Piston Impingement film
22
Conclusions • Port water injection has been successfully demonstrated near current production best in class full load levels (~27 bar BMEP) ⁃ Enabled near MBT Combustion Phasing (water flow limited by instrumentation) on “Regular” 87 AKI Fuel and stoichiometric operation ⁃ Resulted in a significant increase in Net Thermal Efficiency over production across all speeds • 34% @ 3000 RPM
⁃ Resulted in a significant increase in NMEP over production across all speeds Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
23
Next Steps (Near Term) • Evaluate water injection at higher levels of BMEP • Evaluate water injection at increased compression ratio
• Compare Direct Water Injection to Port Water Injection • 1D Simulation of Water Injection
• Reduce water usage though spray targeting and reduction in droplet size
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
24
High BMEP Engine Components • Currently no production engine at this cylinder pressure
• Production intent ⁃ Forged Pistons & Connecting Rods ⁃ High Strength head studs ⁃ 10W40 High ZDDP Synthetic Oil ⁃ Increased valve lift ⁃ Increased valve spring stiffness ⁃ Larger High Pressure Fuel Pump • 83% increase in fuel flow
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
25
Q&A For full powerpoint
Sam Barros Director of Research and Development Nostrum Energy, LLC
[email protected] www.nostrumenergy.com
Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016
26
