Lambda 1 High Load Operation via Water Injection

Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016

Lambda 1 High Load

Operation via Water

Injection

Sam BarrosDirector of Research and Development

Nostrum Energy, LLC

1


• Motivation

• Experimental Setup⁃Engine Setup

⁃Water Injection

⁃Controls

• Simulation

• Experimental Results

• Conclusions

• Next Steps

2

Outline

Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 2016 3

Motivation

• Avoiding this!

• Enabling the next generation of high efficiency engines


• 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

4

Motivation


Experimental Setup

Baseline Engine• SIDI 2.0L GM Ecotec LTG

• Twin Scroll Turbocharger

• Dual Independent Cam Phasing

• Large Aftermarket Support


• Injectors installed in intake manifold

• Direct Injection also an option

6

Experimental Setup – Water Injection

Water

Rail

Injector with Bosses

welded to manifold


• 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

7

Experimental Setup – Water Injection

Building Water Supply

RO Water ReservoirHigh

Pressure Pump

Flow Metering

Device

Air Supply ~110psi

12V Signal

I/O

Drain to Sewer System

Reverse Osmosis Filtration System

Filter

PWI Water Tank

Vent to Atmosphere

Temperature and Pressure Transducers

Port Injectors

Data Acquisition

System

Intake Manifold

Exhaust System

Engine

Temperature and Pressure Transducers

Port Injection

Controller

Exhaust System

Air Supply ~200psi

DirectInjection

Controller

EngineDirect

Injectors


Experimental Tests To Be Discussed

Test

NumberFuel

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 None10° CA50 or

KLSA*Production Production Production

Test 3 87 AKI Port Injection10° CA50 or

KLSA*Production Production 1.0


Experimental Results: Combustion

0

5

10

15

20

25

30

1500 2000 2500 3000 3500 4000 4500 5000 5500

CA50 EA; 91 AKI, Baseline

CA50 EA; 110 AKI, MBT / KLSA

CA50 EA; 87 AKI, MBT / KLSA, Lambda 1

Combustion PhasingBaseline Engine

Engine Speed (RPM)Engine Speed (RPM)

CA

50

(°A

TDC

)

0

5

10

15

20

25

30

35

40

45

1500 2000 2500 3000 3500 4000 4500 5000 5500

BD10-90_EA; 91 AKI, Baseline

BD10-90_EA; 110 AKI, MBT / KLSA

BD10-90_EA; 87 AKI, MBT / KLSA, Lambda 1

Burn DurationBaseline Engine

Engine Speed (RPM)Engine Speed (RPM)

BD

10

-90

MBT


Experimental Results; Output

0

5

10

15

20

25

30

35

1500 2000 2500 3000 3500 4000 4500 5000 5500

NMEP EA; 91 AKI, Baseline

NMEP EA; 110 AKI, MBT / KLSA

NMEP EA; 87 AKI, MBT / KLSA, Lambda 1

Mean Effective PressureBaseline Engine

Engine Speed (RPM)

NET

MEP

(b

ar)


Experimental Results; Efficiency

0

5

10

15

20

25

30

35

40

1500 2000 2500 3000 3500 4000 4500 5000 5500

Net Thermal Efficiency; 91 AKI, Baseline

Net Thermal Efficiency; 110 AKI, MBT / KLSA

Net Thermal Efficiency; 87 AKI, MBT / KLSA, Lambda 1

Net Thermal EfficiencyBaseline Engine

Engine Speed (RPM)

NET

Th

erm

al E

ffic

ien

cy (

%)


Experimental Results: Exhaust Gas Temperatures


Simulation

13

• 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


• Fuel Enrichment and Combustion Phasing both have large impact on Net Thermal Efficiency

• Good opportunity for efficiency improvements

Simulation Results


Simulation Results

15

3

3.25

3.5

3.75

4

4.25

4.5

4.75

5

700 750 800 850 900 950

Airflow (kg/hr)

Pre

ssu

reR

atio

(:)

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

• Boost pressure is

currently supplied via an

external compressor

• Good candidate for

alternative boosting

systems (multi-stage,

compounded)


11.0:1 chosen as a compromise between efficiency, peak cylinder pressure, and

unburned gas temperature (knock propensity)

200

300

400

500

600

700

800

900

1000

-75 -55 -35 -15 5 25 45 65 85 105 125

CR = 9.2:1

CR = 10.0:1

CR = 11.0:1

CR = 12.0:1

Auto-Ignition Temperature; Iso-Octane

Theta (Crank Angle)

Un

bu

rne

dG

as T

em

pe

ratu

re(K

)

Impact of Compression Ratio on Unburned Gas Temperature (3000 RPM, 50 bar BMEP)

A/F = 12.0CA50 = 10° ATDC

Simulation Results

Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 20165/26/2016 17

• Patented jet-to-jet

collision breakup

mechanism

• Reduced spray

penetration and

improved liquid

atomization allow

faster water

vaporization rates

Water Injectors

Engine Expo 2016 – Messe Stuttgart, Germany – May 31st to June 2nd 20165/26/2016 18

• Spray Targeted Nostrum

KiWi; Kinetic Water Injector

• Nostrum Water DI injector

(next phase)

Water Injectors used on this project


PFI Spray Targeting – Symmetric Spray

19

Intake port impingement due to

wider, non targeted-symmetric

spray plume


PFI Spray Targeting – Directional Spray

20

Intake port impingement avoided

significantly by a narrower,

directional spray plume targeted

to the back of the intake valve


PFI Spray Targeting – Directional Spray Movie

21


Liner & Piston Impingement

22

Fuel impingement on

the liner due to

improper spray

targeting

Piston Impingement

film


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

• 5.1% @ 3000 RPM


• 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

24

Next Steps (Near Term)


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

• 19% increase in pump bore


Q&A

26

Sam BarrosDirector of Research and Development

Nostrum Energy, LLC

[email protected]

www.nostrumenergy.com

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Lambda 1 High Load Operation via Water Injection