session 8b: turbochargers technological challenges of ... · pdf filetechnological challenges...

© 2015 MITSUBISHI HEAVY INDUSTRIES MARINE MACHINERY & ENGINE CO., LTD. All Rights Reserved.

Technological Challenges of

Mitsubishi MET Turbocharger

October 2015

MARINE MACHINERY DIVISION

TURBOCHARGER SECTION

Asian Marine Engineering Conference 2015

Session 8B: Turbochargers

© 2015 MITSUBISHI HEAVY INDUSTRIES MARINE MACHINERY & ENGINE CO., LTD. All Rights Reserved.

Items

1. Today’s issues

2. FOC optimization

a. Turbocharger cut out

b. Variable turbine tuning (VT)

c. Exhaust gas bypass system (EGB)

d. Sequential Turbo Charger (STC)

e. Hybrid turbocharger (HTC)

f. Electric assist turbocharger

3. Environmental issue

© 2015 MITSUBISHI HEAVY INDUSTRIES MARINE

MACHINERY & ENGINE CO., LTD. All Rights Reserved. 2

Issue Engine side Turbocharger side

FOC

De-rating

Turbocharger

cut out

VT(Variable Turbine)

EGB(Exhaust Gas Bypass)

HPT(High Pressure Tuning)

STC(Sequential Turbo Charger)

Environmental

EGR

SCR

1. Today’s issue

Engine Load

TC

Eff

icie

ncy

Improved

MET42MB MET66MB

HPT

VT

EGB

EGR test Engine in service

Spec Turning

Integrated EGB Turbo

VTI Turbocharger

Hybrid Turbocharger

Electric assist Turbo

TC cut off

HPT

STC



Modification for

Seal air supply

Turbocharger cut out with rotor shaft

Case: Rotor shaft remained in the cut out turbocharger

Lubricating oil inlet

Close gas inlet

No2. T/C cut-out condition

Seal air supply

Lubricating oil drain Close Air outlet

Close gas outlet

1. Seal air passage

2. Vacuum breaker

+



Turbocharger cut out operation

Test result of effect for scavenging air pressure and FOC

0

0.1

0.2

0.3

0.4

0.5

0.6

Incre

ase

of

sca

ve

ng

ing

air

pre

ssu

re

3 → 2 sets

4 → 3 sets

-7

-6

-5

-4

-3

-2

-1

0

Fu

el consum

ption

3 → 2 sets

4 → 3 sets

0 20 25 40 50 60 Engine Load Fig. 1 Change of scavenging air pressure

Fig. 2 Effect on Fuel consumption

Fig. 3 Operation range of Engine load by one turbocharger cut out

0 20 25 40 50 60 Engine Load

0 20 40 60 Engine Load

Benefit difference of turbocharger cut out between 4 sets and 3 sets

Remark） Running hour : 6500hr/year, Fuel price : 400$/ton

(L1 = 74,760kW)

Engine Load FOC Fuel / year [ton] Fuel cost / year [$]

25%

(18,690kW)▲1g 121 48,594

50%

(37,380kW)▲2g 486 194,376

※ Reference form MDT information



Difference of Engine tuning (VT – EGB – HPT)

HPT

VT

EGB



MET-VTI system

Gas

passage

large

Gas

passage

small

Partition wall Cross section

Gas inlet outer casing

Nozzle

Gas inlet inner casing

Gas control pipe

Butterfly valve

Improve low load engine performance

Reduce operating time of auxiliary blowers

Simple, Low cost Fixed pitch nozzle ring with inner gas flow control passage

Open / Close : two step control

Reliable variable geometry solution No sealing air / cooling air required

Highly reliable butterfly valve (supplied by SOMAS, Sweden)

Open Close



MET-VTI Engine shop test results

Scavenging air pressure

Hitachi zosen corporation

Difference of SFOC

between VTI valve open and close

Improvement of SFOC

−5 ~ −3 g/kWh 0.35 bar increase

at 75% engine load

▲ VTI valve close

● VTI valve open



MET-VTI Service experience

Retrofit photos

Nozzle for VTI Gas inlet inner casing for VTI

with valve

ECS monitor for VTI control

(modified by ACONIS)

Electric wiring and air piping

for valve control (installed by Shipyard)



Integrated EGB system

Butterfly valve with positioner

(Added)

Gas bypass pipe (Added)

Gas outlet guide

with holes

(Modified)

EGB Orifice

(Added)

Gas inlet outer casing

for EGB (Modified)

Gas inlet inner casing

(Same as original)

Nozzle ring

(Same as

conventional EGB)

Integrated EGB model



Integrated EGB system

Integrated EGB product Gas passage inside of T/C

ADVANTAGES

No need for EGB pipe arrangement between exhaust gas receiver and

gas outlet duct to funnel.

Easy to retrofit.

No additional work by shipyard after engine delivery.



Sequential Turbocharging principle

Electronically controlled diesel engine

Scavenging air manifold

Air cooler

Exhaust gas receiver

To funnel

T C

Small turbocharger

Non return valve (One way valve)

T C

Large turbocharger

To

Outside

V2 Air outlet

V1 Gas inlet

Turbocharger combination is;

Small and Large turbo.

Operation of each turbo. is made

by Non-return valve control

Optimization of SFOC is made

by cutting out the small turbo.



Construction of Hybrid turbocharger

Cross section of MET83MAG turbocharger

Flexible coupling

Silencer

Generator support

High speed generator



Electric assist turbocharger

13

MHI-MME developed prototype of electric assist turbocharger and tested on

turbocharger test bed.

October 2013



4.0 4.1 4.2 4.3 4.5 4.6 4.7 4.8 4.9 5.0

Scavenging air pressure (bar abs)

U series

MET-MB

Increased max. speed limit

Robust design for higher speed

MET-MA

V series

Compressor profile

V series U series

Compressor profile

V-series

Straight splitter vane

leading edge

U-series

Curved splitter vane

leading edge

WARTSILA LOW SPEED TIER 2

MAN LOW SPEED TIER 2

Compliance with IMO-NOx Tier II (MET-MB)



Compliance with IMO-NOx Tier III

MET

MET

MET

MET

IN ENGINE LP-EGR

HP-EGR

LP-SCR

HP-SCR

EGR: Exhaust Gas Recirculation, SCR: Selective Catalytic Reduction, LP: Low Pressure, HP: High Pressure

EGR with low press. Loop

(EGR gas is branched after T/C)

EGR with low press. Loop

(EGR gas is branched before T/C)

SCR before T/C

SCR after T/C

T/C

AFTER

TREATMENT

session 8b: turbochargers technological challenges of ... · pdf filetechnological challenges...

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