sherbrooke water injection 2010

8/4/2019 Sherbrooke Water Injection 2010

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Modeling Water Injection in aHighOutput Diesel Engine UsingGTPOWER

David OhDoctorant, Internal Combustion Engines

Department of Mechanical Engineering


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Contents

Introduction

Project Targets

The Engine

GT-POWER ModelSimulation Results

Summary


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Introduction

Diesel vehicles have historically beenassociated as being industrial, smoky,slow and boring


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Introduction

Perceptions are slowly changing


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Project Targets

Explore and push the performance limitof a streetable Diesel-powered car

Most aftermarket tuning is done by intuitionand experience (trial-and-error)

Specific power, torque and RPM to exceedthe Diesel tuning state-of-the-art using

engineering principles and methods Target specs: 150 kW/L (200+ HP/L), 40 bar

BMEP, 5500+ RPM max.


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The Engine

Series engine specs:

VW 4-cyl 2.0L 16V common-rail TDI Diesel

Bore x stroke: 81 x 95.5mm (1968 cm)

Power / torque: 103 kW (140 HP) / 320 Nm


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The Engine

Modified engine specs:

336 kW (450 HP), 658 Nm (485 lb. ft.)

Enlarged pistons (83 vs. 81mm) 2067

cm

Compression ratio reduced to 15:1

Custom common-rail fuel injection system

and standalone engine control unit (ECU) Regulated 2-stage turbocharging using

variable turbine geometry turbos


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The Engine

Heavily-modified

cylinder head

Optimized valvetiming using GT-POWER

Custom piston pins, con rods, bearings

Block reinforcement (ladder frame)Thermal barrier coating on flame-exposed surfaces

Increased cooling/lube oil capacity


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The Engine

Dual Turbochargers

Garrett VNT

(Variable Nozzle

Turbine)

Regulated 2-Stage charging adapted fromauthors M.Sc. thesis (portions presented at

2009 GT-SUITE Users Conference byFEV/RWTH Aachen/BWTS)


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The Engine

GT-POWER simulation results


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The Engine

All this is great, but we have a problem:

Turbocharger Tmax = 850C


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The Engine


Design pmax 225 bar


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The Engine


68kW (92HP) = total brake Pmaxof an economy car engine!


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The Engine


5600W compared to the heat

output of a 19000BTU/hr BBQ!


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The Engine

Solution: Water Injection


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Thermodynamic Review

1st Law for closed-systems( ) ( )PEdKEdduw-q ++=

vmV,dVpW

cycle

==

=

cycle

pdvmW

( )12v21 TTmCdU =mRTPv=

( )

=

=

n1n

1

2

1-n

2

1

1

2

P

P

v

v

T

T


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Thermodynamic Review

Effects of increased water content on air working fluidproperties. Source: Heywood (1988), from Taylor

Percent

changefromn

ormal

air


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GT-POWER Model


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GT-POWER Model

Added water injectors as shown


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GT-POWER Model

Modelling considerations

Enable Condense/Evaporate Water Vapour


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GT-POWER Model

Enable Calculate Water Saturation (Dew)Temperature RLT

Air-fuel ratio, effective lambda and

volumetric efficiency give erroneous results


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Simulation Results

EGT reduced >120 K

Turbocharger Tmax = 850

C


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Simulation Results

PCP reduced 25 bar

Design pmax 225 bar


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Simulation Results

In-cylinder heat transfer reduced 28%


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Simulation Results

HP Compressor

LP Compressor


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Simulation Results


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Simulation Results


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Summary

Water injection has been modeled in GT-POWER and shown to reduce mechanicaland thermal stresses in a highly-rated

turbocharged DI Diesel engine Exhaust gas temperature reduced 120 K and

remains below 850C limit

Peak cylinder pressure reduced 25 bar tobelow 225 bar

In-cylinder heat transfer reduced 28%

Burned zone temperature reduced


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THANK YOU FOR YOURATTENTION!

AcknowledgementsProf. Jean-Sbastien P lante

Louis Breton

sherbrooke water injection 2010

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