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Engines Bergen AS

Fuel Efficiency and Reliability in LNG propulsion

CIMAC NMA Norway Fall Meeting 2014 Hordvikneset 24.09.2014 / Erlend Vaktskjold

Topics

1. How to save fuel cost and reduce exhaust emissions Fuel prices Engine fuel efficiency Exhaust emissions Power management Variable speed - engine and propeller

2. Reliability Loss of propulsion Limited propulsion control Equipment malfunction or damage 3. Examples of LNG propulsion

2

Fuel Prices – Worldwide 3

Chosen values: LNG 10$/GJ

Sources: MDO: Bunker Index MDO http://www.bunkerindex.com/prices/bixfree_1310.php?priceindex_id=4 LNG: Argus Global LNG: LNG Markets, Projects and infrastructure Volume IX, ISSUE 12, Dec 2013; Volume X, Issue 4, April 2014

MDO 20$/GJ

LNG vs Diesel – Fuel Cost 4

20

25

30

35

40

45

50

0 25 50 75 100

Fuel

Eff

icie

ncy

[%]

Power Output [%]

LNGMDO

0

10

20

30

40

50

60

0 25 50 75 100

Fuel

Cos

t [$/

GJ]

Power Output [%]

LNGMDO

LNG vs Diesel – Exhaust Emissions 5

0

50

100

150

200

250

0 25 50 75 100

CO2

emis

sion

[kg/

GJ]

Power Output [%]

LNGMDO

0

50

100

150

200

250

0 25 50 75 100

CO2

emis

sion

[kg/

GJ]

Power Output [%]

LNGMDO

0

4

8

12

0 25 50 75 100

NO

x em

issi

on [g

/kW

h]

Power Output [%]

LNGMDO

LNG vs Diesel – Exhaust Emissions 6

LNG vs Diesel – in the Engine Room 7

Diesel engine – 20.000h Gas engine – 45.000h

Power Mangement

Multiple engines example – 4 generating sets

8

0

5

10

15

20

25

30

35

0 20 40 60 80 100

Fuel

Cos

t [$/

GJ]

Vessel power demand [%]

Variable speed 9

0

5

10

15

20

25

30

35

0 25 50 75 100

Fuel

Cos

t [$/

GJ]

Power Output [%]

Variable Speed

Fixed Speed

0

20

40

60

80

0 4 8 12 16 20

Fuel

Cos

t [$/

NM

]

Vessel Speed [knots]

Variable Speed

Fixed Speed

Summary Fuel Cost and Emissions 10

• Run on LNG • Run as few engines as possible • Run variable engine speed • Run variable propeller speed • (Use twin screw)

40-60Hz

60Hz

Reliability – Types of Faults 11

Fault type Consquence Mitigation

Loss of propulsion «Let go the anchor!» - Very high robustness

in critical elements - Redundancy

Limited propulsion Out of commercial service (off-hire)

- Robustness - Redundancy??

Equipment malfunction or damage

Maintenance / replacement required

- Robustness - Less equipment /

reduced redundancy

Loss of propulsion 12

Diesel (conventional) LNG (lean burn SI)

Major breakdown …

Minor brakdown Onboard spares available

Rudder control

Pump failure, control failure, leakage, etc Pitch control

Clutch control

Fuel supply Major leak Gas leak SD Block valves (4 off, fail to closed)

Pressure drop in LNG tank

Engine shutdown Safety shutdown (prevent major breakdown)

Governor failure Mechanical backup governor on single engines Electronic governor, no backup

Ignition Self-ignition Ignition sys with spark plugs and pickups

Redundancy on fuel supply and engine IS required!

Limited propulsion 13

Diesel (conventional) LNG (lean burn SI)

Rudder backup control Pitch backup control Clutch backup control Air-Fuel control / limit Smoke limiter

Black smoke in case of failure Electronic governor and

actuator Gas pressure control NA Electro-penumatic control

Combustion knocking NA Slow down alarm <40%

Reliability Summary – Loss of, or Limited, Propulsion 14

• Run on LNG • Run as few engines as possible • Run variable engine speed • Run variable propeller speed • (Use twin screw)

40-60Hz

60Hz

(need frequency converter)

(tied to engine speed)

Examples of LNG propulsion

Fjord 1 / E39 Halhjem/Sandvikvåg + Arsvågen/Mortavika • 5 ferries since 2006, 1 more 2013

• Gas – electric propulsion, 2 – 4 main gensets per vessel

• Diesel backup gensets

• 10.000 – 12.000 port calls / year with no incidents

Torghatten Nord / Lofoten • 4 ferries since 2013

• Gas mechanical propulsion – 1 main engine per vessel

• Diesel genset backup through PTI on gearbox

• An unacceptable number of incidents

15

Examples of LNG propulsion

Fjord Line – «Danskebåten» • 2 cruise ferrys 2013

• Gas-mechanical propusion

• 4 main engines, 2 propellers

• Loss of propusion incidents relating to LNG tank pressure drop

Bukser and Berging • 2 tugs operating at Kårstø gas terminal 2014

• Gas-mechanical propusion

• 2 main engines, 2 propellers

• No loss of propulsion incidents

Conclusions LNG propulsion 17

• Significant fuel cost savings • Significant emission reduction - both local and global impact • LNG propulsion is more complex - fuel storage, evaporation and pressure control - engine ignition and air-fuel control ⇒ Individual subsystem is likely to be less reliable System reliability must be restored by overall system design

18 Questions – Comments ?