turbocharging dual-fuel engines Paper no. 187 - ABB Group · turbocharging dual-fuel engines Paper no. 187 C. Christen, D. Brand, CIMAC 2013. GAS MODE ... Combined result of diesel

Simulation-based study on turbocharging dual-fuel engines Paper no. 187

C. Christen, D. Brand, CIMAC 2013

GAS MODE

Low NOx emission

NOx Level < IMO Tier 3

Dual-fuel enginesAs a solution for IMO Tier III

© ABB GroupNovember 26, 2013 | Slide 2

GAS or DIESEL MODE

Regular NOx emission

NOx Level < IMO Tier 2

pric

e4lim

o.co

m/im

ages

sc

ienc

ewor

ld-

front

iers

.blo

gspo

t.com

Dual-fuel enginesEstablished engine technology


Moderate power density

Single stage turbocharging

Low compression ratio

Constant speed or CPP operation

Micro pilot spray ignition

img.

naut

icex

po.c

om

Dual-fuel enginesDevelopment targets: Fuel efficiency and power density

Increased pmax /imep

Increased CR

Miller cycle

Improved closed cycle efficiency

Reduced gas exchange losses

Improved turbocharger efficiency

Fuel-efficient control device

Miller cycle

Lean burn combustion

Extending knock limit to allow for higher bmep

POWER DENSITY

FUEL EFFICIENCY


T no

t bur

ned

Pressure

Dual-fuel engine process design challengesPilot spray ignition vs. knocking combustion


Cyl

inde

rsta

te

Crank angle

Not burned

Temperature

Pressure

Burned

Risk of engine knocking

Risk ofunrealiableignition

T no

t bur

ned

Pressure

Dual-fuel engine process design challengesPilot spray ignition vs. knocking combustion


bmep CR

MillerIgnition Timing

PARAMETER KNOCK IGNITION

BMEP

CR

MILLER

IGNITION TIMING

- +- ++ -

+ +

Risk ofunrealiableignition

Risk of engine knocking

Optimal combination high bmep high efficiency

Boundary conditions / limitations

Max. cylinder pressure pmax Below limit pmax = 220 bar

Turbine inlet temperature TTI Below limit TTI = 530 °C (HFO mode)

Pilot spray ignition delay Below threshold value

Knock integral Below calibrated value

Air fuel ratio V Constant (gas), above limit (diesel)

Cycle optimization simulation resultsCombined result of diesel and gas engine operation


Engi

ne E

ffici

ency

+ M

ot[%

]

Compression ratio [-]

xxx

20

22

24

26

28

bmep [bar]

1% point

2

1% point

Establisheddual-fueltechnology

Case studybmep = 26 bar

Cha

rge

air p

ress

ure

Compression ratio [-]

Cycle optimization simulation resultsHigh compression ratio calls for strong Miller effect


Sing

le-s

tage

Two-

stag

e

2

Establisheddual-fueltechnology

Case study

Cyl

inde

rpre

ssur

e

V / VD [-]

Engine cycle optimization in gas modeImproving gas exchange


Increased turbochargingefficiency

VVT control

EWG control

Throttle control+

+

-

Power2

High charge air pressure for strong Miller timing

High turbocharging efficiency

Air managmentABB’s contribution for optimized engine process


VCM

Fuel efficient air/fuel ratio control device

Flexible Miller timing

Power2

High charge air pressure for strong Miller timing

High turbocharging efficiency for improved fuel efficiency

Paper no. 134

Paper no. 389

Case studySimulation setup and boundary conditions


Simulation Case Bmep CR Turbocharging

systemBore

V

control

Reference 20 bar Ref. single-stage Ref. EWG

VCM 26 bar +4 two-stage -6% VCM

Boundary conditions / limitations

Max. cylinder pressure pmax Below limit pmax = 220 bar

Turbine inlet temperature TTI Below limit TTI = 530 °C (HFO mode)

Pilot spray ignition delay Below threshold value

Knock integral Below calibrated value

Air fuel ratio V Constant (gas), above limit (diesel)

Rated engine power ≈ 5 MW

0.2 0.4 0.6 0.8 1.0 1.2

bsfc

[g/k

Wh]

Engine load [-]

Case study results CONSTANT SPEEDbsfc against reference


Reduction of brake-specific fuel consumption

14 to 20 g/kWh

Increased potential in gas mode at engine part load withskip firing enabled by VCM

GAS MODE DIESEL MODE

skip firing0.2 0.4 0.6 0.8 1.0 1.2

bsfc

[g/k

Wh]

Engine load [-]

10 g/kWh

Reference Reference

Case study results FPPbsfc against reference


Reduction of brake-specific fuel consumption in FPP mode

15 to 20 g/kWh

GAS MODE DIESEL MODE

0.2 0.4 0.6 0.8 1.0 1.2

bsfc

[g/k

Wh]

Engine load [-]0.2 0.4 0.6 0.8 1.0 1.2

bsfc

[g/k

Wh]

Engine load [-]

10 g/kWhReference

Reference

Conclusions

Potential for dual-fuel engines according to simulation

Power2 and VCM as a package allow for a step-change in fuel efficiency and power density

VCM enables FPP operation on dual-fuel engines

Paper no. 187


Paper no. 134

Paper no. 389

感谢您的关注


Thank You for Your Attention

Engine cycle optimizationAir path loss reduction


Compressor Throttle Cylinder

Receiver ExhaustIntake

Pres

sure

pEngine

pEngine,VCM

IncreasedMiller Effect

Open Throttle

pTIincreased turbocharging efficiency

pTI

Engine cycle optimization

Increase of TC system efficiency due to intercooling

Two-stage turbocharging efficiency improvement


1.00

1.05

1.10

1.15

1.20

4 5 6 7 8 9 10

tw

o-st

age

/ si

ngle

-sta

ge[-]

Compression ratio tot [-]

2st / 1st TAmb = 25 °CTIC = 60 °C

Example

Single-stage:

s,C = 82%

Two-stage:

tot = 6-8

s,C,eq >= 90%

Case study

© ABB Group November 26, 2013 | Slide 19

ABB’s Valve Control Management VCMPrototype Testing

VCM has been tested on a medium speed engine

Functionality and mechanical integrity have been proved

Endurance tests have been carried out

> 1000 running hours on mechanical test rig

> 300 running hours on fired engine

The prototype demonstrated maturity for industrial application

VCM prototype module allowing for variability on both intake and exhaust valves

VCM prototype module mounted on small medium speed engine


ABB’s Valve Control Management VCMWorking Principle

Full valve lift mode

Control valve stays closed

Synchronous movement of valves and camshaft

Crank Angle

Valv

e Li

ft


Crank Angle

Valv

e Li

ft

ABB’s Valve Control Management VCMWorking Principle

Early valve closure mode

Control device opens during valve lift period

Valve closes irrespective of camshaft position and the pressure accumulator is charged

As the camshaft is reduced, the pressure accumulator passes its spring energy onto the camshaft


Power Control of Premix Gas EnginesValve Control Management VCM

Crank Angle

Valv

e Li

ft

a) Full lift

b) Early valve closure

c) Late valve opening with reduced lift

d) Double valve lift

e) Zero lift

ba

c

d

Documents

turbocharging dual-fuel engines Paper no. 187 - ABB Group · turbocharging dual-fuel engines Paper no. 187 C. Christen, D. Brand, CIMAC 2013. GAS MODE ... Combined result of diesel