QUANTUM 9000Two-stroke LNGBy DNV and MAN Diesel & Turbo

3Quantum 9000

Contents

Introduction ......................................................................................................5

Concept Overview .............................................................................................6

Trade Route and Operational Profile ...................................................................8

The Engine ...................................................................................................... 11

Exhaust Gas Recirculation (EGR) ..................................................................... 16

Test Experience ............................................................................................... 19

Gas Supply System ......................................................................................... 20

LNG Tanks ...................................................................................................... 23

Class Requirements ........................................................................................ 24

Bunkering ....................................................................................................... 25

Hull Optimisation ............................................................................................. 26

General Arrangement ...................................................................................... 27

LNG Tank Arrangement ................................................................................... 28

Main Engine Room Safety ............................................................................... 28

Recommendations for the Utilisation of Available Energy from LNG .................. 29

Reduction of Power Need for Reefer Containers .............................................. 29

Cool Down Air Supply to Turbocharger ............................................................ 30

Other Cooling Needs ....................................................................................... 30

Ballast Water ................................................................................................... 31

Propeller Optimisation ..................................................................................... 32

Cost-benefit Calculations ................................................................................ 32

Conclusion ...................................................................................................... 34

References...................................................................................................... 34

4 Quantum 9000

5Quantum 9000

Introduction

The need for seaborne transportation

will increase significantly in the years

to come. At the same time, the fuel oil

price is increasing, stricter emission re-

quirements are coming into force, and

the public is becoming more concerned

about the environmental footprint of

shipping. As a result, the industry is in-

vestigating alternative fuels for shipping.

Liquefied natural gas (LNG) is an attrac-

tive option since it reduces the emis-

sions, and is expected to be cheaper

than fuel oil in the future because of the

large world reserves of natural gas.

Background

The use of liquefied natural gas (LNG)

as ship fuel is not a new idea. LNG has

been used for many years on gas car-

riers with boilers (in the case of steam

turbine propulsion), four-stroke diesel

mechanical propulsion or diesel elec-

tric propulsion installed. All these solu-

tions are based on consumption of the

readily available LNG as the fuel, and/

or boil-off gas from the LNG tanks. In

recent years, the LNG infrastructure,

particularly in Norway, has developed

to the extent that other ship types, like

Ro-Ro and smaller ferryboats, use LNG

as the fuel, and it is now established as

a clean and reliable fuel for propulsion

and auxiliary power generation.

In April 2010, DNV presented the LNG-

fuelled container ship concept Quan-

tum. The Quantum concept introduces

a number of innovative solutions to

increase efficiency and reduce the en-

vironmental impact of container ship

operation. Based on input from the in-

dustry, flexibility was found to be the

answer to the many uncertainties fac-

ing the industry in the years to come.

The machinery arrangement is based

on electric propulsion and dual fuel

gensets. This was selected with the

need for flexibility in mind, and is based

on an assessment of the alternative so-

lutions available at the time.

With the recent technology develop-

ment, MAN Diesel & Turbo can now offer

both dual fuel medium speed engines,

and low speed MAN B&W LNG-burning

ME-GI type engines offering propul-

sion power with reduced emissions.

The development of the ME-GI engine

has made it possible to install a simple,

yet unique propulsion power solution,

with a total system efficiency similar to

conventional vessels, but with reduced

emissions. Hence, the further develop-

ment of the DNV Quantum project with

a single propulsion line, using an ME-GI

main engine as the power source, is a

natural and obvious progression for fu-

ture container ship designs to obtain a

reliable, energy efficient, and emission-

friendly LNG solution.

As a result of recent market trends, it

was decided to increase the ship size

from the 6,000-teu range to the 9,000-

teu range. With the new Panama Canal,

this ship size is very relevant for the Asia-

US trade through the Panama Canal. The

hull form and arrangement has, conse-

quently, been modified and optimised for

the new machinery arrangement, ship

size and trade.

Emission regulations

The ME-GI engine will fulfil IMO Tier III

NOx levels when combined with the

exhaust gas recirculation (EGR) tech-

nology. A technology developed by

MAN Diesel & Turbo for the complete

low speed B&W engine programme for

compliance with IMO Tier III NOx emis-

sion regulations.

Quantum 9000

Fig. 1: Quantum 9000

6 Quantum 9000

Methane slip, a problem commonly as-

sociated with dual fuel engines, is not

an issue with the ME-GI engine, due to

operation according to the Diesel cycle

principle. In this respect, the ME-GI is

not vulnerable to the valve overlap, or

localised gas fuel pocket formation on

the cylinder wall, resulting in methane

slip, and which may occur as a conse-

quence of operation according to the

Otto cycle principle.

Concept Overview

Quantum 9000 has been designed to

be more efficient and environmentally

friendly compared with existing ships,

without introducing major complications

in the building and operation of the ship.

The new solution for LNG machinery,

the ME-GI engine, demonstrates that

improvements can be achieved on both

the machinery and hull side, by using

existing and well-proven technology.

The first Quantum concept study in-

troduced a diesel-electric arrangement

with pod propulsion. This is a proven

system in the cruise industry, but new

to the container ship market, where a

single-screw low speed two-stroke so-

lution has been the predominant choice

of propulsion. The Quantum 9000 intro-

duces LNG to the preferred container

ship propulsion system, making it more

available to container ship owners.

Twin island designs are common for big-

ger ships in the 12-14,000 teu range.

Single island has been the common so-

lution for 9,000 teu size. Benefits such

as increased container loading and im-

proved vision from the bridge justifies a

twin island solution also for the smaller

size ship. Collisions and groundings are

among the most common incidents for

container ships. Highlights of the new

concept are outlined below:

Main features

� Gas-fuelled main engine – two-stroke

ME-GI

� Dual fuel auxiliary engines

� Full fuel flexibility (HFO/DFO/LNG)

� Full ECA compliance (Tier III)

� Optimised according to the opera-

tional profile

� Improved EEDI

� Cost-efficient solutions.

Machinery

Efficiency improvements and reduced

emissions are obtained with the MAN

B&W two-stroke ME-GI gas engine. The

benefits are:

� Simple modifications

� Conventional engine room

� Proven performance

� High fuel efficiency

� High fuel flexibility

� High reliability.

Hull design and arrangement

The hull design and arrangement has

been optimised for maximum space uti-

lisation, minimum hull fuel consumption,

minimum need for ballast water, and in-

creased safety. The main benefits are:

� Better space utilisation with twin is-

land

� Greatly improved sightline from the

bridge

� Sufficient LNG capacity without loss

of cargo space

� Pressurised type-C LNG storage

tanks for maximum reliability

� Reduced need for ballast water

� Increased ship beam, reduced block

coefficient

� 4-blade propeller optimisation.

Fig. 3: The hull arrangement

Fig. 2: The ship hull performance

7Quantum 9000

CONTAINER VESSEL “QUANTUM 9000 CONCEPT” Class: DNV CONTAINER CARRIER NAUTICUS(Newbuilding) E0 DG-P TMON BIS LCS-SI

Optional notations: RC-1(1072/131) NAUT-AW CLEAN BWM-T COMF-V3 VIBR F-M

POOP DECK

MAIN DECK

B.L.D.B.

100 20 30 40 50 60 70 80 230 240 250 260 270 280 290 300 310

FORECASTLE DECK

320 330130 140 150 160

23456 179 8

90 100 110 120 220170 180 190 200 210 340 350 360 370 380

MAIN PARTICULARS: Length betw. perpendiculars, Lbp 297.979 m Length overall, Loa 313.845 m Breadth moulded, B 48.0 m Depth moulded, D 26.4 m Draught moulded, T 15.0 m Design draught, Td 13.5 m Min. design draught at AP 13.5 m Min. design draught at FP 13.5 m Block coefficient, Cb (@Td) 0.58 Waterplane area coefficient, Cwp 0.762

Deadweight, design 81,155 t Deadweight, scantling 98,618 t Lightship (esimated/preliminary) 34,432 t

Design speed 22.0 kn (at design draught, 85% MCR / 15% sea margin)

Crew 28 + 6 Suez

TANK CAPACITIES: Heavy Fuel Oil (HFO) 4,000 m3 Liquid Natural Gas (LNG) 6,500 m3 Marine Diesel/Gas Oil (MDO/MGO) 1,600 m3 Lubricating Oil 16 m3 Fresh Water 360 m3 Ballast Water 24,728 m3

All oil tanks according to “MARPOL Oil Tank Protection”

Cruising range approx. 16,000 nm

ENGINE PLANT: Main engine: MAN 9S80ME-C9.2-GI MCR: 40,590 kW @ 78.0 rpm

Propeller: Fixed pitch, 4 blades, dia. 10 m AUX engine/Gen Sets : 4 x 2,500 kW Emergency generator : 1 x 250 kW @ 1,800 rpm Bow Thrusters: 2 x 2000 kW WHR plant (ME @85% MCR ISO): 2,709 kW

CONTAINER STOWAGE: Container capacity (total) 8,708 TEU On deck: 5,570 TEU Below deck (cargo hold): 3,138 TEU

Reefer capacity (total) 1,203 FEU On deck: 1,072 FEU Below deck (cargo hold): 131 FEU

Rows (max) on deck / in cargo hold 19/17

Tiers (max) on deck / in cargo hold 9/9

Pontoon hatch covers (composite/light weight): Hatch 01C (1x): 12.97 x 24.27 m Hatch 02F PS & SB (2x): 12.97 x 10.85 m Hatch 02F C – 09A C (14x): 12.97 x 17.63 m Hatch 02A PS – 09A PS (13x): 12.97 x 13.38 m Hatch 02A SB – 09A SB (13x): 12.97 x 13.38 m

Stability:

14t/TEU, 8’6” high, 50% HcG 6,539 TEU

Fig. 4: Quantum 9000 concept – ship design data

8 Quantum 9000

Trade Route and Operational Profile

Based on recent market trends, the

9,000-teu range was selected as the

target case for the concept develop-

ment, together with the Asia–US east

coast trade route through the new Pan-

ama Canal, see Fig 5.

For several years, since the building of

the first Post-panamax container ves-

sel in 1988, the existing Panama Canal

has been too small for the larger con-

tainer vessels. In order to accommo-

date a larger proportion of the current

and future fleet, and thereby the cargo

carriage through the Panama Canal, the

Panama Canal Authority has decided

to extend the existing two lanes with a

bigger third lane with a set of increased

size of lock chambers.

The lock chambers will be 427 m long,

55 m wide and 18.3 m deep, allow-

ing passage of ships with a maximum

breadth of 49 m, maximum passage

draught of 15 m and an overall maxi-

mum ship length of 366 m. The new ca-

nal is scheduled to open in 2014 at the

100th anniversary of the existing canal,

and to be fully in operation in 2015.

When serving the east coast of USA,

there is another limitation that needs to

be observed. Ships entering the Newark

container terminal in Port of New York

must pass under the Bayonne bridge.

The air draft limitation is currently 151

feet, which imposes a restriction on the

bigger ships. There has been news in

the press that the bridge may be raised,

giving a new air draft of 215 feet, but

this is yet to be confirmed.

Operational profile

In order to achieve a high efficiency in

the operational phase, it is necessary

to understand the operational demands

when the ship is designed. An opera-

tional profile must be made before opti-

misation of the hull and machinery can

be started.

If the ship is to operate on a speci-

fied trade, the operational profile can

be determined on the basis of on an

optimisation of the actual trade route.

Optimising the hull and machinery for

a wide range of speeds and draughts

is difficult. Therefore, the ideal situation

is to define the route so that the ship

can operate close to the design point

for as much of the time as possible. Fig.

7 shows the operational profile defined

Yokohama

Shanghai

Hong KongKaohsiung

Newark

CharlestonSavannah

Panama

Oakland

Los AngelesYokohama

Shanghai

Hong KongKaohsiung

Newark

CharlestonSavannah

Panama

Oakland

Los Angeles

Fig. 5: Trade route

Time in operating state as percentage of total leg time

0,0%

10,0%

20,0%

30,0%

40,0%

50,0%

60,0%

70,0%

80,0%

90,0%

100,0%

Leg 2 Leg 3 Leg 4 Leg 5 Leg 6 Leg 7 Leg 8 Leg 9 Leg 10 Leg 11 Leg 12 Leg 13

Voyage leg

Tim

e [%

] of

leg

tim

e

Saling 10 [kn]

Saling 12 [kn]

Saling 21,5 [kn]

Port man.

Load/unloading

Refuelling

Waiting

Fig. 7: Operational profile

Fig. 6: Panamax and Post-panamax vessel particulars

9Quantum 9000

for this concept, including all sailing legs

and all operational modes. The required

propulsion power and electric power

demand has been calculated for each

leg and operational mode.

Trade is often unknown at the design

stage, or it is expected that the trade

may change during the ship’s life. In that

case, it may be better to establish the

operational profile using statistics from

operation. The example below is show-

ing time spent at various speeds, and

time at various drafts and trims for one

specific speed. It should be noted that

operational patterns from the past are

reflecting market conditions and fuel

prices, and are not necessarily repre-

sentative of the future.

Based on the operational profile se-

lected, the hull and machinery should

be optimised to give the highest pos-

sible efficiency when the entire route is

considered, rather than only the design

speed and draught. For the hull, this

applies especially when it comes to

the main dimensions, block coefficient,

centre of flotation and bulb design.

For the machinery, it is the selection of

main engine and auxiliary engines so

that the propulsion power and electric

power needed can be produced as ef-

ficiently as possible in all the different

sailing legs and different operational

modes.

Design according to the operational

profile

Container ship designers have opti-

mised the ship at the point of maximum

fuel consumption, which is normally at

maximum speed and maximum dwt/

draught. Any savings made at this point

will probably yield the maximum gain.

A design point or interval has to be se-

lected for optimisation, as it is difficult

to optimise over a large range of condi-

tions. Savings can be made in one point

at the expense of a loss in other points.

So it is important to understand how

the vessel is going to be operated, both

with regard to speed and loading.

There was an oversupply of ships in

the market during the financial crisis

in 2009, and profitability suffered. Fuel

could be saved by reducing speed, but

the need for a regular service remained.

More ships had to be added to the serv-

ice loop when average speed dropped.

The additional ships would also burn

fuel, but the net cost reduction still re-

mained substantial. The extra ships em-

ployed also reduced the number of idle

ships during the crisis.

The slow steaming experience led to

a focused interest on optimal speed

of container ships. The optimal main

dimensions and hull lines will vary de-

pending the speed and draught. Could

savings in fuel and emissions be in-

creased if the speed and DWT profile

was taken into consideration when op-

timising? We will illustrate how this can

be done in the example below.

Fig. 10 shows the relationship between

speed and power for three different

draughts. The graph illustrates that the

maximum power is consumed at max.

draught and max. speed. Detailed pow-

er data are given in Table 1.

Speed distribution and dwt/draught dis-

tribution may be obtained from the ex-

pected operational profile coupled with

actual recordings and past experience.

0%

5%

10%

15%

20%

25%

30%

18 19 20 21 22 23 24 25SPEED [knots]

Time [weighed kw]

Fig. 8: Operational profile

7

Drafta [m]

8

9

10

Distance

Trim [m] 0.5

Trim [m] 1

Trim [m] 1.5

Trim [m] 2

Trim [m] 2.5

Trim [m] 3

Fig. 9: Operational profile

Fig. 10: Speed-power curves

P13 = 7,897V 2,6745

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

18 19 20 21 22 23 24 25SPEED [knots]

POWER [kw]

T=13

T=11

T=10

10 Quantum 9000

As the future operations are uncertain,

a “probability distribution” of speed and

loading may be a better term. A typical

example is shown in Table 2 where the

percentage of operating time spent at a

given draught and speed is given.

The weighted power consumption is

given in Table 3.

The percentage time at a given speed

interval is presented in Table 4. The

power consumed at different draughts

and speeds can now be weighted and

combined in a power curve for various

draughts and speed intervals. This is

shown in Table 5 and Fig. 11. From the

graph it can be seen that the greatest

weighted power consumption is in the

interval 19.5–22 knots.

This information can then be used for

choice of optimising interval, which will

give the highest probable saving for fu-

ture operations.

Fig. 11

0

1,000

2,000

3,000

4,000

6,000

7,000

18 19 20 21 22 23 24 25

SPEED [knots]

POWER profile [kW] at V and T

Biggest effect of optimisation

5,000

Weighted Power Consumption

Speed [knots] 18 19 20 21 22 23 24 25

Draft T10 13,799 16,192 18,867 21,751 24,927 28,540 32,313 36,459

Draft T11 15,155 17,716 20,562 23,638 27,011 30,799 34,785 39,138

Draft T13 17,976 20,772 23,824 27,145 30,741 34,622 38,800 43,277

Table 1: Power [kW] at different drafts

Speed [knots] 18 19 20 21 22 23 24 25

Draft T10 37% 33% 17% 12% 13% 13% 5% 4%

Draft T11 48% 45% 65% 68% 69% 69% 65% 35%

Draft T13 15% 22% 18% 20% 18% 18% 30% 61%

Table 2: Time [%] at different drafts

Speed [knots] 18 19 20 21 22 23 24 25

Draft T10 5,106 5,343 3,207 2,610 3,240 3,710 1,616 1,458

Draft T11 7,274 7,972 13,365 16,074 18,638 21,252 22,610 13,698

Draft T13 2,696 4,570 4,288 5,429 5,533 6,232 11,640 26,399

Table 3: Weighted power [kW] at different drafts

Speed [knots] 18 19 20 21 22 23 24 25

Speed time [%] at speed V 2% 15% 25% 24% 15% 10% 6% 3%

Table 4: Time [%] at different speeds

Speed [knots] 18 19 20 21 22 23 24 25

Power [kW] at T and V 302 2,683 5,215 5,787 4,112 3,119 2,152 1,247

Table 5: Power [kW] at different speeds and drafts

Data given in Tables 1 to 5 and Figs. 10 to 11 are for illustration purpose only, and does not reflect in detail the Quantum 9000 data

11Quantum 9000 11

The Engine

The ME-GI engine is not a new engine

in technological terms, rather a natu-

ral development of the MAN B&W low

speed electronically controlled ME fam-

ily of engines. In 1987, the first testing

of the GI principles was carried out on

one cylinder of a 6L35MC two-stroke

engine in Japan and Denmark.

The MC/ME/ME-B engine types are

well-proven products in the station-

ary power plant industry, Ref. [1]. The

GI solution was developed in parallel

with standard engine types, and com-

pleted for testing in the early 1990s. In

1994, the first two-stroke GI engine, a

12K80MC-GI-S, was put into service on

a power plant at Chiba, Tokyo, Japan.

So far, the Chiba engine has operated

� Ventilation system for venting the

space between the inner and outer

pipe of the double-wall piping

� Sealing oil system, delivering sealing

oil to the gas valves separating con-

trol oil and gas

� Control oil supply for actuation of gas

injection valves

� Inert gas system, which enables

purging of the gas system on the en-

gine with inert gas.

The GI system also includes:

� Control and safety system, com-

prising a hydrocarbon analyser for

checking the hydrocarbon content of

the air in the double-wall gas pipes.

The control and safety system is de-

signed to “fail to safe conditions”. All fail-

ures detected during gas fuel running,

including failures of the control system

itself, will result in a gas fuel stop/shut-

down and a changeover to HFO opera-

tion. Blow-out and gas-freeing purging

of the high-pressure gas pipes and of

the complete gas supply system will fol-

low. The changeover to fuel oil mode

is always done without any power loss

on the engine. The operation modes for

gas are illustrated in Fig. 14.

as a peak load plant for almost 20,000

hours on high-pressure gas.

At the same time, in 1994, all major

classification societies approved the GI

concept for stationary and marine ap-

plications. Technically, there is only a

small difference between fuel and gas-

burning engines. The gas supply line

is designed with ventilated double-wall

piping and HC sensors for safety shut-

down. The GI control and safety sys-

tems are add-on systems to the normal

engine systems.

Apart from these systems on the engine,

the engine and auxiliaries will comprise

some new units. The most important

aspects, apart from the gas supply sys-

tem, are listed in the following:

Fig. 12: ME-GI engine

Fig. 13: ME-GI engine add-ons compared to the standard ME engine

12 Quantum 9000

The ME-GI engine gives good flexibility

in selecting the best fuel. Based on an

environmental and economic perspec-

tive, the owner can choose a vessel de-

signed to accommodate fuel stores for

both HFO and LNG.

The pilot oil can be low-sulphur marine

gas oil for ignition and back-up fuel,

particularly useful when sailing in emis-

sion controlled areas (ECA). This means

that the ECA sulphur emission require-

ments can be met even when the two-

stroke main engine has to switch off gas

operation at very low loads.

Fuel-oil-only mode:

� Operation profile as conventional engine

Gas-fuel-operation modes:

� Gas mode “minimum fuel”

� Full operation profile

� Full load acceptance

� Full power range

� Load variation by gas injection

� Full pilot fuel oil flexibility

� Minimum pilot fuel used

� Increased pilot fuel at low loads

� Dynamic mix of gas and fuel oil

� Mixed mode “Specified gas”

� Full operation profile

� Gas fuel is specified on Gas MOP

� Load variation by fuel oil injection

Gas

Gas

Fuel/Pilot oil

Fuel/Pilot oil

100%

1009590858757065605550454035302520151050

1009590858757065605550454035302520151050

90%

80%

70%

60%

50%

40%

30%

20%

10%

0%

100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0%

Gas mode ‘Minimum fuel’

Mixed mode ‘Specified gas’

Fuel

inde

x %

Fuel

inde

x %

Engine load (%SMCR)

Engine load (%SMCR)

Automatic

Fig. 14: ME-GI engine operation modes

13Quantum 9000

Engine selection

The ship speed, hull lines and propel-

ler size selected for this container ship

design require a two-stroke low speed

9S80ME-C9.2-GI engine to fulfil the re-

quirements, with 15% sea margin and

10% engine operation margin. Fig. 15

shows a 3D model of the engine.

This engine has the following main data:

� Power: .......................... 40,590 kW

� Speed: ................................ 78 rpm

� Bore: ................................. 800 mm

� Stroke: .......................... 3,450 mm

� Length: ........................ 14,102 mm

� Width: .......................... 5,280 mm

� Height: ......................... 13,500 mm

� Weight: ........................... 1,130 ton

The SFOC figures shown in Table 6 are

based on an engine tuned for waste

heat recovery. This means that the ex-

haust temperatures are slightly higher to

support waste heat recovery utilisation.

Expected Pilot and Gas Fuel Consumptions and Heat Rates

Engine shaft power

Specific pilot fuel oil (re lcv 42,700 kJ/kg)

Pilot fuel oil con-sumption (re lcv 42,700 kJ/kg)

Specific gas fuel consumption (re lcv 50,000 kJ/kg)

Gas fuel consump-tion per day (re lcv 50,000 kJ/kg)

Total heat rate of fuel (re lcv)

Heat rate of pilot fuel oil (re lcv)

Heat rate of gas fuel (re lcv)

% SMCR g/kWh t/24h g/kWh t/24h kJ/kWh kJ/kWh kJ/kWh

100.0 8.5 8,294 138.4 134.867 7,285.8 363.6 6,922.2

95.0 8.8 8,154 137.2 126.943 7,234.7 376.2 6,858.5

90.0 9.1 8,008 136.0 119.279 7,192.4 390.0 6,802.4

85.0 9.5 7,857 135.1 111.849 7,159.1 405.2 6,753.9

80.0 9.9 7,700 134.3 104.632 7,134.8 421.9 6,712.9

75.0 10.3 7,536 133.6 97.603 7,119.9 440.4 6,679.4

70.0 10.8 7,365 133.1 90.742 7,114.6 461.2 6,653.5

65.0 11.3 7,185 132.9 84.141 7,128.5 484.5 6,644.0

60.0 12.0 6,996 132.9 77.689 7,156.9 511.1 6,645.8

55.0 12.7 6,796 133.1 71.302 7,195.6 541.6 6,654.0

50.0 13.5 6,583 133.3 64.936 7,243.0 577.1 6,665.9

* 45.0 14.5 6,356 131.6 57.700 7,200.3 619.1 6,581.2

* 40.0 15.7 6,111 131.9 51.380 7,262.6 669.7 6,592.9

* 35.0 17.1 5,845 132.0 45.002 7,331.5 732.0 6,599.4

* 30.0 19.0 5,552 131.9 38.549 7,406.5 811.3 6,595.3

* 25.0 21.5 5,225 131.4 32.008 7,487.5 916.1 6,571.3

Fig.15: 3D model of the selected

two-stroke 9S80ME-C9.2-GI engine

* The exhaust gas bypass valve is closed at engine loads below 50.0 %. The main engine is operating in fuel oil mode below 25.0% SMCR power.

Table 6: Two-stroke low speed 9S80ME-C9.2-GI engine and fuel SFOC figures

14 Quantum 9000

Waste Heat Recovery (WHR)

The most efficient way to increase the

total efficiency of a ship with a two-

stroke engine is to utilise the waste heat

of the engine. Waste heat is collected

primarily from the heat energy of the

engine exhaust gas. Technology with

power turbines, i.e. steam turbines in

combination with high-efficiency tur-

bochargers and boilers, has already

shown total system efficiencies of 55%.

This corresponds to a 10% increase in

efficiency over a standard engine instal-

lation without WHR and, thereby, 10%

lower fuel consumption and CO2 emis-

sions. The highest theoretical efficiency

is close to 60%.

If waste heat recovery is combined

with NOx reduction methods and EGR

(exhaust gas recirculation), the total ef-

ficiency can be raised to approximately

58%. For overview, see Fig. 16.

A limited number of ships have been

built with such systems over the past 25

years. Shipowners’ interest in WHR sys-

tems has so far been heavily dependent

on the cost of HFO, the expectations

to the development in the cost of HFO

and, furthermore, the willingness of the

shipyards to deliver ships designed and

built for the WHR concept. From 2009,

there has been an increasing interest in

waste heat recovery systems, especial-

ly during times of rising fuel prices. They

will be of particular interest because of

the Energy Efficient Design Index (EEDI)

that is expected for future ship designs.

The most used waste heat recovery

steam system is a dual pressure sys-

tem, as illustrated in Fig. 17.

Shaft poweroutput 49.3%

Fuel 100%(171 g/kWh)

12K98ME/MC Standard engine versionSMCR: 68,640 kW at 94.0 r/minISO ambient reference conditions

Lubricating oilcooler 2.9%

Jacket watercooler 5.2%

Exhaust gas25.5%

Air cooler16.5%

Heat radiation0.6%

Dual pressureexhaust gasboiler

LP steam

HP steam

Steam Turbine

Turbochargers

PTI

Main engine 27 - 80 MWmech Steam turbine 1.0 - 5.3 MWelPower turbine 0.5 - 2.7 MWelTotal power generation 1.5 - 8.0 MWel

GeneratorPower Turbine

AuxiliaryDieselEngines

CentralControlPanel

Exhaust Gas Receiver

Main Engine

WHR boosting cycle efficiency from 49.3%to approx. 55.0% (+11.5% recovery rate)

HP-steamfor heatingservices

Condenser

Feedwaterpump Condensater

pump

LP-steam drum

HP-steam drum

HP-circ. p.

LP-circ. p.LP-Evaporator

HP-Preheater

LP-Superheater

HP-Evaporator

HP-Superheater

Exhaust gas

HP

Turbine unit

LPHP

Exh. gas boilersections:

LP

Surplusvalve

HP

Jacket water

Exhaust gas receiver

Main engine

Scavenge air cooler

TC TC

Hot well

Powerturbine

Steamturbine

Fig. 16: Waste heat recovery possibilities

Fig. 17: Dual steam pressure and feed water diagram as normally used onboard

container ships of today

MAN B&W Diesel15Quantum 9000

This type of steam and feed water sys-

tem secures a high utilisation of the

waste energy in the main engine ex-

haust. Fig. 18 shows where the heat

transmission takes place

The steam generated is used to drive a

steam turbine as offered by MAN Diesel

& Turbo, an example of this unit can be

seen in Fig. 19.

The two-stroke 9S80ME-C9.2-GI en-

gine with a waste heat recovery system

will be able to produce the following

electric output (Table 7) depending on

the main engine load and temperature

conditions

Engine ISO Tropical

load condition condition

% WHR output WHR output

– kWe – kWe100 3,836 (9.5%) 4,460 (11.0%)85 2,709 (6.7%) 3,218 (7.9%)75 2,166 (5.3%) 2,613 (6.5%)

50 1,290 (3.2%) 1,584 (3.9%)

Table 7: Electric output from the WHRS based

on the selected ME-GI engine for this container

ship study

Installation of waste heat recovery sys-

tems on board container ships must be

coordinated in detail by the shipyard, as

these systems take space in the engine

room and casing, see Fig. 20 showing

all main components relative to each

other on a container vessels.

The arrangement of a waste heat re-

covery system must be planned in

detail to support the functionality of all

components involved. Nevertheless, if

correctly managed and integrated, the

shipowner will have an advantage with

respect to both total fuel consumption

and meeting future emission demands.

Temperature °

SuperheatedHp steam

SaturatedHp steam

Exhaust gas boiler sections:A: HP-superheaterB: PH-evaporator C: HP-preheaterD: Possible LP-superheaterE: LP-superheater

SuperheaterLP

Exhaust

Min. 20

10 bar abs/180

4 bar abs/144

Steam/water

Min. 15

EDCBA

Exhaust

Feedwater proheated be alternative WHR sources

% Heat transmission0 2 4 6 8 10

25

20

30

15

10

5

0Ambient

Fig.18: Temperature and heat transmission diagram for a dual steam pressure waste heat

recovery exhaust boiler

Fig. 20: Typical engine room and casing

arrangement including advanced high power

waste heat recovery system for a large con-

tainer vessel

Fig. 19: Steam & power turbine unit

16 Quantum 9000

Shut down valveScrubber

Prescrubber

Blower

SeaWMC

FW

Cooler

Sludgetank

Watercleaning

Polis

hing

Scrubber pump

NaOHtank

NaOHpump

Buffertank

Change over valve

Dischargecontrol valve

On/off valve

Stopvalve

Exhaust outlet

MixCoolerWMC

Fig 21: EGR process diagram

Exhaust Gas Recirculation (EGR)

EGR is one of many methods to cut NOx

emissions from marine diesel engines.

The method of EGR has been used on

four-stroke engines, but it has not yet

been commercially available for large

two-stroke marine engines. By recircu-

lating part of the exhaust gas, a minor

part of the oxygen in the scavenge air

is replaced by the combustion products

CO2 and H2O. Besides reducing the O2

percentage in the combustion chamber,

the heat capacity of the combustion air

will be slightly increased and the temper-

ature peaks of the combustion will be re-

duced. Accordingly, the amount of NOx

generated in the combustion chamber is

reduced. The NOx reduction ratio is de-

pendent on the ratio of recirculation, but

is also followed by a minor fuel penalty.

Fig. 22: EGR fore end arrangement on a

two-stroke B&W 5S60ME-C8.2 engine

The EGR system on this ship will be

integrated with the main engine, an

example of which is shown in Fig. 22

below for a 5S60ME-C8.2 type engine.

The 9S80ME-C9.2-GI selected in this

project requires two turbochargers, so

the EGR system is therefore placed on

the fore end of the engine.

The principle of an EGR system is

shown in Fig. 21. Part of the exhaust

gas is diverted from the exhaust gas re-

ceiver through a scrubber, which cleans

the gas and reduces the temperature of

the exhaust gas. The gas flows through

a cooler, a water mist catcher and the

EGR blower, which raises the pressure

to the right scavenge air pressure. The

ratio of recirculation is controlled by the

blower, which in turn is controlled by

the oxygen content ratio of scavenge air

and exhaust.

A water handling system is installed in

connection with the scrubber. This sys-

tem controls the function of the scrub-

ber using a closed loop freshwater

system with the addition of an active

substance.

MAN B&W Diesel17Quantum 9000

Specification of the EGR system for a B&W 9S80ME-C9.2-GI

Gas systemEGR scrubber 1 (or 2) Integrated on engineEGR pre-scrubber 1 (or 2) Integrated on engineEGR cooler 1 (or 2) 17,600 kW Integrated on engineEGR water mist catcher 1 (or 2) Integrated on engineEGR blower - frequency controlled 1 (or 2) 760 kW Integrated on engineShutdown valve 1 (or 2) Integrated on engineChange-over valve 1 (or 2) Integrated on engineCompensators 2 (or 4) Integrated on engine

Water treatment system WMC drainers - placed below WMC 3 (or 6) Integrated on engineScrubber drainers - placed below WMC 2 (or 4) Integrated on engineDirty buffer tank - placed below drainers 2 m3 stainless Water treatment unitClean buffer tank 2 m3 stainless Water treatment unitSludge tank 15 m3 stainless Ship systemWater cleaning unit (WCU) 120 m3/h 120 kW Water treatment unitClean water outlet valve 1 Ship systemFeed pump – frequency controlled 120 m3/h 3 bar 16 kW Water treatment unitScrubber pump – frequency controlled 100 m3/h 10 bar 48 kW Water treatment unitNaOH storage tank - 50% NaOH solution 50 m3 stainless Ship systemNaOH day tank - 50% NaOH solution 1 m3 stainless Water treatment unitNaOH dosing pump 250 l/h 2 bar 0.2 kW Water treatment unitCooling water Cooling water for EGR Cooler 850 m3/h 2 bar Ship systemElectrical systemFrequency converter – feed pump 1 (or 2) In WTS cabinetFrequency converter – scrubber pump 1 (or 2) In WTS cabinetFrequency converter – blower 1 (or 2) Brake resistance for blower 1 (or 2) Electrical cabinet – WTS 1 Water treatment unitControl system EGR CU – MPC control system 1 Engine control roomEGR control display 1 Engine control roomWater handling CU – PLC control system 1 Engine control room

Water handling display 1 Engine control room

Table: 8

18 Quantum 9000

Emission data

The application benefits of the EGR sys-

tem are described in the emission data

diagrams shown in Fig. 23 and Fig. 24.

Assumptions:

Liq: HFO, 3% S, 86.7%C, LCV 42,700

Gas: LNG, 74.97% C, LCV 50,000

EGR system included for Tier III

Pilot fuel 5% at 100% load

Fig. 24: Emissions Main engine running on 100% HFO

Fig. 23: Emissions – Main engine running on LNG with pilot oil

405

410

415

420

425

430

435

440

445

450

455

460

0

2

4

6

8

10

12

14

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

CO2(g/kWh)NOx & SOx (g/kWh)

Engine Load (% SMCR)NOx - Tier II NOx - Tier III SOx CO2

540

545

550

555

560

565

570

575

0

2

4

6

8

10

12

14

16

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

CO2(g/kWh)NOx & SOx (g/kWh)

Engine Load (% SMCR)NOx - Tier II NOx - Tier III SOx CO2

MAN B&W Diesel19Quantum 9000

Test ExperienceEGR in Service on Alexander Maersk

From August 2008 until March 2010,

MAN Diesel & Turbo has developed,

designed, and manufactured the very

first Exhaust Gas Recirculation (EGR)

system for a two-stroke marine diesel

engine for operation on a container ves-

sel in service.

In partnership with A. P. Moller - Maersk,

the EGR prototype system has been in-

stalled, and commissioned, on the ves-

sel Alexander Maersk. The 1,092-teu

container vessel was built in 1998, and

it is currently sailing between Southern

Europe and Northern Africa. The main

engine is a Hitachi B&W 7S50MC Mk 6,

with a specified maximum continuous

rating of 10,126 kW at 127 rpm, origi-

nally equipped with two turbochargers.

Service test objective

The main objective of the service test is

to investigate the impact of running with

EGR on the main engine, i.e. cylinder

condition, exhaust system condition,

and EGR system condition. Besides

performance, settings and controlling,

the software needs to be tested “in situ”

in order to tune the control system for

best possible performance.

The EGR system developed for Alex-

ander Maersk is designed for minimum

20% recirculation of the exhaust gas,

which corresponds to minimum 50%

reduction of the NOx emitted, compared

with the basis emission level.

Design of a retrofit EGR system

The first retrofit EGR system is specifi-

cally designed for installation on Alex-

ander Maersk, using expertise obtained

during years of testing on the 4T50ME-X

research engine in Copenhagen. The

main EGR components are the scrub-

ber, cooler, water mist catcher, blower,

shutdown and changeover valves, water

treatment plant (WTP), water cleaning

unit (WCU), control, and safety systems.

The exhaust gas is drawn through the

scrubber, cooler, and water mist catch-

er, by suction created from the blower.

The exhaust gas is pressurised by the

blower, and then mixed with the charge

air in a unique charge air pipe before

entering the main engine coolers.

Within the scrubber, the exhaust gas

is mixed with water, which then be-

comes acidic due to the sulphur in the

exhaust gas dissolving in the water.

NaOH dosing is therefore required to

neutralise the acidic scrubber water. A

significant amount of particulate mat-

ter (PM) will also become suspended in

the scrubber water, which will also need

to be handled in the water treatment

unit (WTU). It is therefore necessary to

have a water cleaning unit (WCU) that

can remove the PM from the scrubber

water, and discharge it as concentrated

sludge into the sludge tank on the ves-

sel. The WCU is designed for cleaning

the scrubber water to enable discharge

of the cleaned water into open sea in

compliance with the IMO scrubber wa-

ter discharge criteria.

In order to make the EGR system easy

to operate for the ship crew and to en-

sure correct and fast reactions to en-

gine load variations, a fully automated

EGR control system was developed.

A standard MAN Diesel & Turbo MPC

controller is used as the main controller,

and as a secondary system, a PLC is

used for controlling the WTU.

Installation of EGR

In July 2009, Alexander Maersk docked

at Lisnave shipyard for 30 days, during

which all the large EGR components

were installed and the majority of the

installation work was completed.

The EGR unit (consisting of the scrub-

ber, cooler, water mist catcher, and

blower) was installed on the middle plat-

form, adjacent to the exhaust receiver

on the main engine. The two original

turbochargers were removed, and a

single high-efficiency turbocharger with

variable turbine area was installed in

their place, with the new charge air pipe

that distributes the mixture of charge

air and recirculated gas between the

two existing main engine coolers. The

main engine cooler elements were re-

placed with special nano-coated cooler

elements to prevent such corrosion

that might otherwise occur due to the

condensation of sulphuric acid caused

by possible carry-over of SOx. The re-

maining equipment and pipework for

the WTU was installed in the starboard

corner of the engine room, on the main

floor.

EGR in service

Commissioning of the EGR system

on Alexander Maersk commenced in

March 2010. All gas and water pipe

work has been pressure-tested, the

system functionality has been estab-

lished, and an initial service test after

500 hrs. has been scheduled to evalu-

ate the performance of the EGR sys-

tem. An additional 3,000 hrs. in service

is then planned for further evaluation of

the EGR. An important part of the serv-

ice test is to assess the effect of EGR

on a main engine over a period with the

engine running on heavy fuel oil (HFO).

20 Quantum 9000

The preliminary results from the com-

missioning phase have met our expec-

tations to the EGR system performance.

After some minor modifications, the sys-

tem is now fully functional.

ME-GI

The first gas-fuelled two-stroke engine

went into operation in July 1994, at

the Chiba power station in Japan. This

12K80MC-GI-S engine went on to op-

erate on gas fuel for 20,000 hrs. from

1994 to 2001, successfully proving the

technology behind the MAN Diesel &

Turbo two-stroke gas-fuelled engine

concept. The engine concept has been

class approved, and all the experience

gained from Chiba has been incorpo-

rated into the ME-GI engine design.

In order to promote the ME-GI concept

further, MAN Diesel & Turbo has de-

cided to make a full-scale demonstra-

tion and performance verification test of

the gas injection principle for all kinds of

marine applications on its R&D research

engine, which was rebuilt to a 4T50ME-

GI engine ready to operate on natural

gas at the beginning of 2011.

MAN Diesel & Turbo sees significant

opportunities arising for gas-fuelled

tonnage, as fuel prices rise and exhaust

emission limits tighten. Indeed, previ-

ous research indicates that the ME-GI

engine, when combined with exhaust

gas recirculation (EGR) and waste heat

recovery (WHR) technologies, delivers

significant reductions in CO2, NOX and

SOx emissions and, thereby, fulfilling

Tier II and Tier III regulations.

The test plan continues the momentum

built up at a ceremony in Copenhagen

in 2010, where MAN Diesel & Turbo

signed an agreement with Korea’s Dae-

woo Shipbuilding & Marine Engineering

Co., Ltd. (DSME) to jointly develop and

exploit the adaptation of DSME’s high-

pressure cryogenic gas-supply system

for installation with the ME-GI engine.

ME-GI two-stroke engines features

economical and operational benefits

compared with other low speed engine

plants, irrespective of ship size. Based

on the successful electronically con-

trolled ME heavy-fuel-burning diesel

engines, the ME-GI design accommo-

dates natural gas and liquid fuels.

MAN B&W ME-C and ME-GI engines

are broadly similar, and essentially

share the same efficiency, output and

dimensions. In comparison, the key

components of the ME-GI engine are

its modified exhaust receiver, modified

cylinder cover with gas injection valves

and gas control block, an enlarged top

gallery platform, high-pressure fuel sup-

ply pipes, and gas control units.

Gas Supply System

Dual fuel operation with ME-GI requires

the injection of both pilot fuel and gas

fuel into the combustion chamber. Dif-

ferent types of fuel valves are used for

this purpose, with two additional valves

fitted for gas injection together with the

two original HFO fuel valves, which are

used for pilot fuel injection.

As known from LNG carriers, the ar-

rangement of LNG systems on board

ships must fulfil class rules – more

about this in the section titled “Class

requirements”.

The fuel gas supply (FGS) system for

the ME-GI engine requires a delivery

pressure of 300 bar and a temperature

of 45ºC ±10ºC. Today, several supply

companies can deliver high-pressure

cryogenic pumps or compressor sys-

tems to fulfil these requirements, see

Fig. 25.

Fig. 25: LNG FGS unit suppliers

MAN B&W Diesel21Quantum 9000

These suppliers have experience with

FGS systems, and are able to supply

LNG tanks for ME-GI projects in some

cases. In this project, the most relevant

FGS system consists of a high-pressure

cryogenic pump with capacity for BOG

GCU *

No boil off gas pressurized tank

Fuel tanks

HP pumpLNG Drum

LNG damper

Cool down and mini flow line

LNG vaporizer

Supply system

ME-GI engine

Two-stroke engine

M

PCPC

* Optional

Fig. 26: LNG Fuel Gas Supply (FGS) system with high-pressure cryogenic pump (courtesy of

Cryostar)

ACCU

V5

V3

GAS BLOCK

GASVALVE

FUELVALVE

CONTROLOIL

PILOT OIL

FUELVALVE

GASVALVE

SEALING OIL

ELFI

XC6103

PT6110

PT6405

HYDRAULIC OIL DRAIN

FUEL OIL INLET

FUEL OIL DRAIN

ELGI

FUEL OILPRESSUREBOOSTER

HYDRAULIC OIL

SEALING OIL UNIT

ELWI

DRAIN

PT6104

621

620

421 420

6333XT

V4 625

FUEL GASSUPPLY SYSTEM

V1NC

V2NO

SILENCER

V7NC

ZSZSZS ZS

ZS

PT

ZS

SILENCER

PT

Gas controlsystem

601760116010

6013 6012

6015 60166006

Gas venting pipe

K3

INERT GASDELIVERING

UNIT

PT

V9

6321

6023

ZS

6022

ZS

NC

V6NC

AIR SUPPLY 7BAR

P9 P2

??????

XC6001

INERT GASDELIVERING

UNIT

XC6018

XC6014

XC6019

9BAR

XC6320

<0,1bar

6021

ZS

6020

ZS

PT6024

INSIDEENGINEROOM

OUTSIDEENGINEROOM

INERT GAS SYSTEM

GAS SUPPLY SYSTEMCYLINDER COVER

XT6231

XT6232

VENTINGAIRINTAKE

XC

XT

AIR SUCTION

FS6302

6332

FS6303

6312

VENTILATINGSYSTEM FORTHE ENGINE

SEALING OIL SYSTEM

HYDRAULIC OIL,PILOT OIL,SEALING OIL SYSTEM

Fig. 27: Diagram of ME-GI auxiliary systems

burn off in a gas combustion unit. In

fact, for all vessel types other than LNG

tankers it would probably not (depend-

ing on tank size/route) be necessary to

have a reliquefaction system installed

on board, and a high-pressure cryo-

genic pump would be the most energy

efficient method of gas fuel delivery to

the ME-GI engine. The energy required

by the FGS system is very low, and cor-

responds to an approx. 0.5% reduction

of the efficiency of the ME-GI engine

compared with an ME-C engine.

The gas injection valve design is shown

in Fig. 28. This valve complies with tra-

ditional design principles of the com-

pact design. Gas is admitted to the

gas injection valve through bores in the

cylinder cover. To prevent a gas leak-

age between the cylinder cover/gas

injection valve and the valve housing/

spindle guide, sealing rings made of

temperature and gas resistant material

have been installed. Any gas leakage

through the gas sealing rings will be led

through bores in the gas injection valve

to the space between the inner and the

outer shield pipe of the double-wall gas

piping system. Such a leakage will be

detected by HC sensors.

Head – Gas valve

Housing

Spring

Spindle

Spindle guide

Holder

NozzleSealing ring

O-ring

Fig. 28: Gas injection valve

22 Quantum 9000

The gas acts continuously on the valve

spindle at a max. pressure of about

300 bar. To prevent gas from entering

the control oil actuation system via the

clearance around the spindle, the spin-

dle is sealed by sealing oil at a pressure

higher than the gas pressure (25-50 bar

higher). The pilot oil valve is a standard

ME fuel oil valve without any changes,

except for the nozzle. The fuel oil pres-

sure is constantly monitored by the GI

safety system in order to detect any

malfunctioning of the valve. The fuel oil

valve design allows operation solely on

fuel oil up to SMCR, with capacity for

10% above SMCR once every consec-

utive 12-hour period. In the gas engine

mode, the ME-GI can be run on fuel oil

at 100% load at any time, without stop-

ping the engine. However, for prolonged

operation on fuel oil, it is recommended

to change the nozzles and gain an in-

crease in efficiency of around 1% when

running at full engine load.

As can be seen in Fig. 29, the ME-GI

injection system consists of two fuel oil

valves, FIVA (fuel injection valve actua-

tor) to control the injected fuel oil profile,

and two fuel gas valves, ELGI (electron-

ic gas injection) for opening and clos-

ing of the fuel gas valves. Furthermore,

it consists of the conventional fuel oil

pressure booster, which supplies pilot

oil in the dual fuel operation mode. The

fuel oil pressure booster is equipped

with a pressure sensor to measure the

pilot oil on the high-pressure side. As

mentioned earlier, this sensor monitors

the functioning of the fuel oil valve. If

any deviation from a normal injection is

found, the GI safety system will not al-

low opening for the control oil via the

ELGI valve. In this event, no gas injec-

tion will take place.

Under normal operation where no mal-

functioning of the fuel oil valve is found,

the fuel gas valve is opened at the cor-

800

600

400

200

00 5 10 15 20 30 3525 40 45

Deg. CA

Bar abs

Pilot oil pressure

Control oil pressure

Low pressure fuel supply

Fuel return

Inje

ctio

n

Gas supply

Position sensor

Measuring andlimiting device.Pressure booster(800-900 bar)

300 bar hydraulic oil.Common withexhaust valve actuator

The system provides:Pressure, timing, rate shaping, main, pre- & post-injection

FIVA valve

ELGI valve

Fig. 29: ME-GI fuel/gas injection system.

rect crank angle position, and gas is in-

jected. The gas is supplied directly into

an ongoing combustion. Consequently,

the risk of having unburnt gas, eventual-

ly slipping past the piston rings and into

the scavenge air receiver, is considered

very low. Monitoring the scavenge air

receiver pressure and combustion con-

dition safeguards against such a situa-

tion. In the event of too high a combus-

tion pressure, the gas mode is stopped,

and the engine returns to burning fuel

oil only. The gas flow to each cylinder

during one cycle is be detected by

measuring the pressure drop in the ac-

cumulator. By this system, any abnor-

mal gas flow, whether due to seized gas

injection valves or blocked gas valves, is

detected immediately. In this event, the

gas supply is discontinued and the gas

lines are purged with inert gas, and the

engine continues running on fuel oil only

without any loss of power.

MAN B&W Diesel23Quantum 9000

LNG Tanks

For merchant ships, several possibili-

ties of equipping the ship with an LNG

tank are available. For smaller ship

sizes, prefabricated vacuum-isolated

cryogenic tanks can be found in a wide

range of sizes with an allowable work-

ing pressure of up to 20 bar. Some of

these tanks have been installed and are

already in operation on ferries and sup-

ply vessels.

For bigger ships, several other possi-

bilities exist, some of which are listed

below:

� Membrane tank design

Dominating for LNG carriers, but vul-

nerable to sloshing.

BOR range 0.14-0.2%/day.

� Spherical tanks, i.e. Moss type

Self-supporting and invulnerable to

sloshing, but space problems and

very few manufacturers.

BOR 0.14-0.2%/day.

� IHI type B tanks

Self-supporting and invulnerable to

sloshing. Low-pressure tanks and

built on a licence in some yards.

BOR 0.14-0.2%/day.

� TGE type C tanks

Single or bilobe design, 4 barg pres-

sure vessel tank design (up to 50

travelling days), self-supporting and

invulnerable to sloshing.

BOR 0.21-0.23%/day.

The IHI B-type tank design and the C-

type design from TGE seem to be the

most promising for larger conventional

ships. Common for both tank designs

is that it is possible to operate the ship

with a partially filled tank, which is a ba-

sic requirement when using the tank for

fuel storage. The above tank designs

have advantages and disadvantages.

For instance, in the IHI design it is pos-

sible to adapt the tank form to follow

the shape of the ship. Practically any

tank size can be chosen. In the TGE de-

sign, the hull form can only be followed

to some extent if the bilobe design. The

max. tank size in the bilobe design is in

the range of 20,000 cum.

The space required for the LNG tanks

is almost 2.5 times the size of an HFO

tank system, due to lower density and

the heavy insulation required to keep

the LNG cold – an area where shipyards

need to develop new arrangement ideas.

An advantage of the TGE tank design

is the ability to accumulate the BOG in

the tank during operation, thanks to its

allowable working pressure of up to 4

barg. If a non-pressurised tank design

is used, an alternative method to han-

dle BOG has to be incorporated in the

fuel gas supply system. Therefore, the

C-type tank has been chosen for this

project, eliminating the need for any reli-

quefaction system. The pressure rise in

the LNG storage tanks for this vessel is

illustrated in Fig. 30.

With this in mind, it can be concluded

that the technology for a gas driven

two-stroke ME-GI engine is available.

2,0

2,5

3,0

3,5

4,0

4,5

0,00 5 10 15 20 25 30 35 40 45

0,5

1,0

1,5

Tank pressure [bar g]

Sailing time [days]

Pressure increase estimation for type C tanks

  

 4 bar g designmax. level: 90.3%   

 

Tank volume: 2x2,500m3

Insulation: 300mm PS/PUInitial pressure: 140 mbar g

LNGcomposition:N2: 2%CO2: 0%C1: 89%C2: 5.5%C3: 2.5%C4: 1%

304L: 2.5 bar gmax. level:  92.6% 

Fig 30: Pressure rise in LNG storage tanks for Quantum vessel courtesy of TGE Marine Gas

Engineering

24 Quantum 9000

Class Requirements

The gas engine, LNG tanks and gas

fuel systems are designed according

to the requirements set out in the DNV

class rules for gas-fuelled engine instal-

lations [2] and IMO's Interim Guidelines

on safety for natural gas-fuelled engine

installations in ships [3], as summarised

in the following.

Redundancy

The propulsion and fuel supply system

must be so designed that the remaining

power for propulsion and power gener-

ation after any gas leakage with follow-

ing safety actions is in accordance with

the requirements for remaining power

and main functions after a single failure.

The ME-GI main engine has full fuel flex-

ibility, meaning that the fuel oil is also a

back-up fuel for the LNG.

Engine room and piping

The engine room is designed as an in-

herently gas safe machinery space. This

implies that the engine room is consid-

ered gas safe under all conditions, nor-

mal as well as abnormal conditions.

All gas supply piping within the machinery

space boundaries must be enclosed in a

gas tight enclosure, i.e. double wall pip-

ing or ducting. Gas fuel piping must not

be led through accommodation spaces,

service spaces or control stations. Gas

pipes passing through enclosed spaces

in the ship must be enclosed in a duct.

This duct must be mechanically under-

pressure ventilated.

Gas piping must not be located less

than 760 mm from the ship’s side. An

arrangement for purging gas bunker-

ing lines and supply lines with nitrogen

must be installed. The double piping

between the forward tank room and

the engine room is fitted in the dou-

ble bottom, with the required distance

from side and bottom. Gas supply lines

passing through enclosed spaces must

be completely enclosed by a double

pipe or duct.

The arrangement and installation of the

high-pressure gas piping must provide

the necessary flexibility for the gas sup-

ply piping to accommodate the oscillat-

ing movements of the engine, without

running the risk of fatigue problems.

The length and configuration of the

branch lines are important factors in

this regard.

Storage tanks and tank room

The tank room boundaries must be

gas tight. The tank room must not be

located adjacent to machinery spaces

of category A. If the separation is by

means of a cofferdam, then additional

insulation to class A-60 standard must

be fitted. Access to the tank room is as

far as practicable to be independent

and direct from open deck.

The storage tank used for liquefied gas

must be an independent tank designed

in accordance with the Rules for Clas-

sification of Ships, Pt.5 Ch.5 Sec.5,

which is in accordance with the IMO

International Gas Carrier Code (IGC

Code). The tank is to be either an IMO

type A, B or C tank. Here, a type C tank

is used.

Pressure relief valves must be fitted.

The outlet from the pressure relief valves

must be located at least B/3 or 6 m,

whichever is greater, above the weather

deck and 6 m above the working area

and gangways. It must be possible to

empty, inert and purge bunker tanks

and associated gas piping systems.

Gas in a liquid state with a maximum

acceptable working pressure of 10 bar

can be stored in enclosed spaces. The

gas storage tank(s) must be located as

close as possible to the centreline and:

� minimum, the lesser of B/5 and 11.5

m from the ship side

� minimum, the lesser of B/15 and 2 m

from the bottom plating

� not less than 760 mm from the shell

plating.

In the current concept, the distance to

side and bottom satisfies the above re-

quirements. For vessels other than pas-

senger vessels, a tank location closer

than B/5 from the ship side may be ac-

cepted and approved by the Society,

on a case by case basis.

The storage tank and associated valves

and piping must be located in a space

designed to act as a secondary barrier

in case of a liquid gas leakage. Alterna-

tively, pressure relief venting to a safe

location (mast) can be provided. The

space must be capable of containing

leakage and be isolated thermally, so

that the surrounding hull is not exposed

to unacceptable cooling in the event

of a liquid gas leakage. This second-

ary barrier space is called “tank room”

in other parts of this chapter. When the

tank is double-walled and the outer

tank shell is made of cold resistant ma-

terial, a tank room could be arranged as

a box fully welded to the outer shell of

the tank, covering all tank connections

and valves, but not necessarily all of the

outer tank shell.

MAN B&W Diesel25Quantum 9000

Bunkering station

The bunkering station must be located

so that sufficient natural ventilation is

provided. Stainless steel drip trays must

be fitted below liquid gas bunkering

connections and where leakages may

occur. The drip trays should be drained

over the ship’s side by a pipe that pref-

erably leads down near the sea. The

surrounding hull or deck structures

must not be exposed to unacceptable

cooling in case of leakage of liquid gas.

The bunkering system must be so ar-

ranged that no gas is discharged to the

air during filling of the storage tanks.

A manually operated stop valve and a

remote operated shutdown valve in se-

ries, or a combined manually operated

and remote valve must be fitted in every

bunkering line close to the shore con-

necting point. It must be possible to

release the remotely operated valve in

the control location for bunkering op-

erations and/or another safe location.

Means must be provided for draining

the liquid from the bunkering pipes at

bunkering completion. Bunkering lines

must be arranged for inerting and gas

freeing. The bunkering pipes must be

gas-free during operation of the vessel.

In addition to the above requirements,

the rules contain specific requirements

to ventilation, gas detection and fire

protection of tank room, engine room

and bunkering station.

Bunkering

The availability of LNG and how to

bunker it is often put forward as the

main challenge when it comes to run-

ning large ocean-going ships on LNG.

A number of LNG terminals exists

around the world, and more are under

construction, but so far only Northern

Europe has infrastructure for LNG bun-

kering ready.

The most realistic bunkering option in

the short term is taking LNG directly

from the international trading network

for LNG. Here, there are three different

sources of bunker; import terminals, ex-

port terminals and LNG carriers. Bunker-

ing directly from an LNG import or export

facility would represent no major techni-

cal barriers. However, the container ship

has to sail to the terminal location, which

could represent a substantial cost.

A better option is to take LNG from

import/export terminals via dedicated

LNG carriers or bunkering barges to a

suitable bunkering location. The con-

tainer ship would dock alongside the

carrier/barge, or the LNG carrier/barge

could dock alongside vessel while it is

loading/unloading.

This solution is flexible with the possibil-

ity of low investment cost in the case of

the existing LNG carrier option. Bunker-

ing from a LNG barge to a ship is not a

technical challenge, since LNG transfer

between LNG carriers is already being

done today. However, when it comes to

LNG fuel bunkering, there is a regula-

tory gap that needs to be filled to cover

this type of operation.

In order to limit the need for bunker ca-

pacity on the ship, it is proposed to re-

fuel LNG once in Asia and once in US.

There are currently terminals in both

places that could be suitable for bun-

kering. Fig. 32 shows a map of existing,

proposed, approved and under con-

struction liquefaction and regasification

facility stations in Japan. It is assumed

that refuelling would take place at a sta-

tion close to Yokohama.

In the US, refuelling is assumed to take

place on the West Cost, at Port Dolphin

outside of Los Angeles. This is an ap-

proved LNG terminal not yet built.

The refuelling time is currently estimated

to 8 hours, but it is expected that the

bunkering rate can be increased in the

future, so that the refuelling time can be

reduced. Ship-to-ship transfer of LNG

is done with several thousand cbm/h

so, technically, high bunkering rates are

achievable. However, as bunker supply

infrastructure is not yet in place, there

are no supply vessels available with large

diameter connections and high capacity

pumps. A bunkering rate of about 800

cbm/h is considered realistic to start with.

If the ship must go to a dedicated bun-

kering site, some time will have to be

added for this operation. In principle,

the bunkering could also take place in

the container terminal while loading and

unloading cargo, which would eliminate

the extra bunkering time for LNG refu-

elling. However, this would have to be

approved by the port authorities in each

relevant port.

Fig. 31: LNG transfer from LNG carrier to LNG

bunker barge

26 Quantum 9000

In preparation for bunkering, the fuel

tank pressure should be lowered as

far as possible by use of spray pumps,

shutdown of “pressure build-units” and

– if available – switching compressors to

direct suction from vapour phase. Fur-

ther, the bunker piping must be cooled

down by circulating LNG.

Hull Optimisation

The ship hull has to be designed for op-

timal efficiency according to the opera-

tional profile defined. The design speed

for Quantum 9000 is 22 knots, which

is lower than the normal design speed

for modern large container ships. In

addition, containerships are in the fu-

ture likely to operate at a wide range of

speeds. Modern engines and propulsion

systems are designed with great flexibil-

ity and are capable of running at various

power settings. However, the ship, as a

system, will operate at a high efficiency

level only if also the hull is designed to

operate at off-design conditions. A flex-

ible hull design with respect to the op-

erating speed and displacements will

translate into a reduction of fuel costs

and emissions to air, thus making the

ship more profitable and greener. Vari-

ous hull parameters have been studied

to arrive at the optimal main dimensions

and hull lines. The resulting hull has a

wider beam and a lower block coeffi-

cient than conventional designs.

The new Panama Canal dimensions give

designers more freedom when deter-

mining the hull length and breadth, while

the maximum draught is still restricted

by port limitations. Several hull parame-

ters need to be evaluated in order to op-

timise the hull efficiency: length, breadth,

block coefficient, longitudinal centre of

floatation and bulb shape, among oth-

ers. Computational Fluid Dynamic (CFD)

tools are used to optimise the main hull

dimensions. The wave patterns and the

pressure distribution on the hull can be

estimated and used to compare differ-

ent possible design alternatives

Fig. 33 shows the difference in wave

pattern at design draught and design

speed for a hull with two different block

coefficients. Here it can be seen that

the hull with the higher block coefficient

has more pronounced forward shoulder

and aft shoulder waves in addition to a

more prominent stern wave system.

Fig. 33: 1 Wave pattern at design draft, 22

knots: Cb=0.58 (top) vs Cb=0.62 (bottom)

A study has been carried out to assess

the length/breadth ratio. The breadth

of a container ship can only be varied

in steps determined by the container

width. Starting with a beam of 45.5 m,

the breadth was increased to 48 m and

50.5 m. The latter is over the maximum

breadth of 49 m allowed by the new

Panama Canal, but it was included for

comparison purposes. The effect of the

change of breadth on the hull resistance

is illustrated in Fig. 34. The figure covers

a speed range from 16 to 24 knots. The

resistance is shown relative to a breadth

of 48 m. It can be seen that the effect

of breadth is negligible at the design

speed, while at lower speeds the wid-

er hulls have lower resistance. Hence,

a wider beam is likely to have a lower

resistance in average, and allows for a

reduction in ship length at the same dis-

placement.

Fig. 32: Existing, proposed, approved and under construction liquefaction and regasification facil-

ity stations in Japan

MAN B&W Diesel27Quantum 9000

Fig. 34: Hull resistance for different vessel

breadths shown as ratio to the 48 m hull

Having selected the beam, a study was

carried out to determine the optimum

block coefficient. A block variation from

0.58 to 0.62 was investigated, as seen

in Fig. 35. Typically, the block coefficient

for similar container ships is higher. It

can be seen that the penalty in resist-

ance of increasing the block coefficient

at higher speeds is heavy. However, at

speeds lower than 21 knots, a higher

Cb would give higher hull efficiency. It

should also be remembered that a cer-

tain increase in resistance at high speed

would result in a heavier fuel penalty

than the same reduction in resistance

at lower speeds.

Fig. 35 Hull resistance for different block coef-

ficients shown as ratio to the Cb=0.58 hull.

General Arrangement

The main target for the arrangement is

to have maximum loading capacity tak-

ing into account the space needed for

LNG tanks. A twin island arrangement

is found to have clear benefits in this

respect.

Midship section

In the Quantum 6000-teu design, the

deck has been made wide with a nar-

row ship side to maximise the loading

capacity in the hold and on deck. How-

ever, for the larger Quantum 9000-teu

the wide deck solution is not possible

due to the New Panama Canal limita-

tion. For the same reason, a narrow

ship side does also not give any benefit,

as illustrated in Fig. 36. Hence, a con-

ventional midship section is chosen.

Twin vs single island

The twin and single island options were

investigated and compared. It became

clear that a twin island solution gives

the best loading capacity, in addition

to a number of other benefits. This is

mainly due to the SOLAS visibility line

requirement, shown in Fig. 37, which for

a twin-island concept allows higher teu

stacks forward in the ship.

The twin island solution is also benefi-

cial when space is needed for the LNG

tanks. As a result, the teu capacity in-

creased by over 10% compared with a

conventional single island design.

The main advantages with a twin island

solution are:

� Maximizing carrying capacity

� Possible to place LNG tanks in the

area below fwd wheelhouse

� Achieve better crew comfort thanks

to lower vibration levels

� Reduce hatch cover deformations fwd

� Less shaft length since E/R more aft

� Better load distribution, reduced trim

and need for ballast water

� Increased safety by better visibility

� Better load distribution, giving lower

bending moment and reduced trim

� Better sight, giving reduced collision

risk when maneouvering in port

The disadvantage of the twin island is

somewhat increased building cost, and

some operational challenges due to the

large distance between superstructure

and engine room.

The final general arrangement is shown

in Fig. 36.

0.90

0.95

1.00

1.05

1.10

14 16 18 20 22 24 26

Rt [ratio to Rt 48]

V [knots]

B = 45.5 mB = 48.0 mB = 50.5 m

0.90

0.95

1.00

1.05

1.10

1.15

14 16 18 20 22 24 26

Rt [ratio to Rt 0.58]

V [knots]

Cb = 0.58Cb = 0.60Cb = 0.62Cb = 0.64

Fig.36: Midship section

28 Quantum 9000

LNG Tank Arrangement

The Quantum 9000-teu has an LNG

storage capacity of approximately

6,500 m3 LNG, divided on two tanks of

2,500 m3 below the forward deckhouse

and an LNG day tank next to the engine

room with storage capacity of 1,500

m3. The tank arrangement is shown in

Fig. 38 and 39. The fuel oil is located in

cofferdam bulkheads with a capacity of

4,000 tons, giving the ship full flexibility

to run on HFO or LNG. As the concept

is focusing on available technology,

the LNG fuel tanks chosen are of the

C type, which is state of the art today.

These are standard reliable tanks with

long service experience. They are capa-

ble of pressure build-up in case of zero

consumption, and can accommodate

high bunkering rates. Installation is also

quick and easy. The main disadvantage

is the space requirement, which may

lead to development of new, prismatic

tank types in the future.

Main Engine Room Safety

A recently completed investigation, initi-

ated by a group of players in the LNG

market, questioned the use of a 250-

bar gas supply in the engine room.

Especially if located under the ship’s

accommodation area, where the crew

is working and living. Even though the

risk of full rupture of both the inner and

outer pipe at the same time is consid-

ered close to negligible, and in spite of

the precautions introduced in the sys-

tem design, MAN Diesel & Turbo found

it necessary to investigate the effect of

such an accident, as the question re-

mains in parts of the industry; what if a

double-wall pipe fully ruptures and gas

is released from a full opening and is ig-

nited?

As specialists in the offshore industry,

DNV was commissioned to simulate

such a worst-case situation, study the

consequences and point to the appro-

priate countermeasures. DNV’s work

comprised a CFD (computational fluid

dynamics) simulation of the hazard of

an explosion and subsequent fire, and

an investigation of the risk of this event

ever occurring and at what scale. As

input for the simulation, the volume of

the engine room space, the location

of major equipment, the air ventilation

rate, and the location of the gas pipe

and control room were the key input

parameters.

Realistic gas leakage scenarios were

defined, assuming a full breakage of

the outer pipe and a large or small hole

in the inner fuel pipe. Actions from the

closure of the gas shutdown valves,

the ventilation system and the ventila-

tion conditions prior to and after detec-

tion were included in the analysis. The

amount of gas in the fuel pipe limits the

duration of the leak. Ignition of a leak

causing an explosion or a fire is further-

more factored in, due to possible hot

spots or electrical equipment that can

give sparks in the engine room.Fig. 38: LNG tank section frame

Fig. 39: LNG tank illustration

Fig. 37: Difference in “line of sight” between single and twin island

MAN B&W Diesel29Quantum 9000

Calculations of the leak rate as a func-

tion of time, and the ventilation flow

rates were performed and applied as

input to the explosion and fire analyses.

Recommendations for the Utilisation of Available Energy from LNG

When bunkering LNG, you also bunker

available energy (exergy) that can be

used for cooling purposes. Today this

potential is not utilised; instead most

systems use extra energy to pump

heating fluids like seawater and glycol/

water to the LNG fuel systems.

When this “added cooling value” for

LNG is utilised, it will improve the LNG

cost picture, although it is not taken into

consideration in the final cost-benefit

assessment in this paper.

The Quantum 9000 concept operates

at a load of 85 % MCR most of the time,

using LNG and a small amount of pilot

fuel:

� Gas consumption (from LNG) at 85

% MCR: 134,1 g/kWh

� Pilot fuel consumption at 85 % MCR:

10 g/kWh

The heating capacity needed for regasi-

fication of LNG to NG is approximately

3.5-4 % of the engine capacity running

on natural gas (or LNG percentage);

two-stroke low speed engines like the

ME-GI engine is located in the lower in-

terval due to temperature rise in the LNG

during compression to 300 bar (~10°C

rise).

Based on the main engine gas con-

sumption at 85 % load and the need

for heat exchange for regasification, we

have approximately 1,000 kW available

for cooling purposes. The upper part of

this heat exchange (to raise the natural

gas to 45°C) has to be done against a

heat source with a matching tempera-

ture interval, like the main engine high

temperature cooling circuit. The quest

is to minimise the net heat transfer to

the surroundings (air & sea).

First priority should be to utilise cooling

needs close to the engine room (cold

box/room) for reasons of feasibility and

the costs involved. The air conditioning

system, engine related measures and

cargo holds near the engine room and

cargo holds with reefers are good can-

didates for this purpose.

The available energy (exergy) from LNG

regasification varies with engine load

(SFOC), for engine loads below 25 %

the engine runs on fuel oil only (engine

limitation).

It is therefore clear that the system de-

sign and flexibility is currently restricted,

and the easiest way to exploit the cold

LNG that needs to be vaporized is to

modify the systems that have to cope

with “normal” conditions without LNG

available for cooling.

The available energy for cooling pur-

poses could be utilised to:

1. Reduce power consumption for reef-

er containers. Shave off peak air tem-

peratures in the cargo hold

2. Aproximately 7°C is achievable when

running in gas mode at 85 % MCR

(5-10 % reduction in power need for

reefer containers)

3. Cool down the air supply to turbo-

charger or main engine. Potential to

cool down air supply to turbocharger

or main engine which results in a gain

in main engine efficiency

4. Other cooling needs. ~20-30% ad-

ditional reduction in power need for

seawater cooling pumps when used

in combination with frequency con-

verters

Peak temperatures in air and seawa-

ter tend to increase the power need

per degree more than at lower ambi-

ent temperatures; overall gain might be

best if measures are combined.

Reduction of Power need for Reefer Containers

The Quantum 9000 concept has 131

reefer containers below deck in cargo

holds. Reefer containers are the second

largest power consumer after propul-

sion; they need a lot of power and air

changes.

To control the peak temperature in the

cargo holds with reefer containers would

result in a reduction in power consump-

tion. It might also lead to a reduction in

power need for cargo hold fans if the

available cooling capacity results in the

use of a lower air ratio per reefer con-

tainer, today this might vary from 60 to

100 m3/h per reefer container.

If we study different datasheets from

producers of reefer machines, we see

that the power curves are steeper at

high ambient temperatures; rise in

power need from 40 to 45°C is approxi-

mately twice the rise in power need

from 30 to 35°C.

30 Quantum 9000

For the Quantum 9000 concept the po-

tential to cool down the air supply to the

cargo hold is approximately 7°C, based

on the main engine LNG use at 85%

load:

� The air supply temperature to the car-

go hold is reduced from 35 to 28°C,

and the power need for reefer con-

tainers is reduced by ~5% (~350,000

kWh saved per year)

� The air supply temperature to the car-

go hold is reduced from 45 to 38°C,

and the power need for reefer con-

tainers is reduced by ~8% (~490,000

kWh saved per year)

� The air supply temperature to the

cargo hold is reduced from 50 to

43°C, and the power need for reef-

er containers is reduced by ~10%

(~650,000 kWh saved per year)

Lowering the supply air temperature to

cargo holds with reefer containers gives

a moderate direct saving. Spin-off sav-

ings like maintenance reductions and

fewer “problems” with temperature-

sensitive goods might further improve

the potential savings. Conservative de-

sign values for air changes and ambient

temperatures also put restrictions on

the savings potential.

The cargo mix and the type of reefer

containers affect the potential savings.

A state-of-the-art reefer container has

advanced automatic controls and soft-

ware that adjust air changes, tempera-

ture and, thereby, power consump-

tion in a way that 25-50 % savings are

achievable. With such state-of-the-art

reefers in the cargo hold, the gain of

controlled air temperature to the cargo

hold could be further improved.

Real life data for reefer power con-

sumption at different ambient tempera-

tures is not easily available and also

varies with type and quality (baseline vs.

state of the art); an old reefer container

may need two times as much power

as state-of-the-art reefer containers.

Future work together with shipown-

ers/operators of container ships, reefer

makers and other manufacturers would

be the best way to improve the overall

energy efficiency and gain experience

while maintaining the flexibility to oper-

ate under all conditions (with or without

the energy available from LNG).

Cool Down Air Supply to Turbocharger

Utilising the low-temperature LNG to

lower the inlet air or charge air tempera-

ture increases the power and torque of

the main engine; keeping the inlet air or

charge air temperature as low as possi-

ble, but not below the minimum allowed

temperature specified by the engine

maker improves the energy efficiency of

the engine.

Based on the main engine air need and

LNG use at 85% load, the available

cooling energy from the LNG regasifica-

tion has the potential to cool down the

air supply to the turbocharger with ap-

proximately 12-13°C; a maximum 0.7

% gain in energy efficiency of the main

engine could be achieved in this case

dependent on the main engine tun-

ing characteristics, however, there are

some technical challenges to overcome

in order to accomplish this.

Another option is to cool down the

charge air, using a medium to transfer

the cooling effect from LNG vaporisation

to the main engine coolers; a maximum

of 0.6% gain in energy efficiency could

be achieved in this case dependent on

the main engine tuning characteristics.

Other Cooling Needs

Maximum savings are achieved for heat

exchange against direct cooling needs

like air conditioning where the power

input is about one third of the cooling

need. If the Quantum 9000 concept

needed 1000 kW for air condition-

ing (cooling), then the potential sav-

ing would be approximately 330 kW

(~30%). Designing the air conditioning

needs for Quantum 9000 was not part

of the scope, so these values are given

to illustrate potential savings.

Another energy efficiency candidate is

the seawater cooling system, where it

is important for the engine maker that

the system delivers the cooling capacity

needed at any condition.

For a water pump, a 50% volume flow

gives an 87.5% reduction in power con-

sumption with speed reduction instead

of throttle regulation (affinity laws).

1

1

22 Q

nnQ ×

1

3

1

22 P

nnP ×

The use of frequency converter for sea-

water pumps to optimise pump speed

according to ambient seawater tem-

perature is deemed to be a low-hanging

fruit for energy efficiency improvements

and, typically, saves approximately

50%. This figure varies according to the

operational profile and sailing pattern.

With LNG available for cooling this

saving will be improved and amplified

(constant cooling at reduced flow gives

increased temperature difference); we

can control and lower the seawater

temperature to the central cooler most

MAN B&W Diesel31Quantum 9000

of the time without tampering too much

with the system. When LNG is not avail-

able, the frequency converter will opti-

mise the power use based on ambient

conditions.

Additional 20-30% reduction in power

need for seawater cooling is expected

when used in combination with fre-

quency-converter-controlled seawater

pumps.

Although the potential savings of uti-

lising the cryogenic LNG energy avail-

able are moderate, the costs involved

to achieve this savings are small com-

pared with many other possible meas-

ures considered today. To utilise the

available energy (exergy) in LNG for

cooling purposes leads to increased

savings instead of increased costs.

Ballast Water

Sailing with ballast water comes with a

cost, both due to the significant amount

of energy necessary to transport the

seawater across the oceans, and due

to the cost of treating it. Eliminating or

reducing the amount of ballast water

needed in future ship designs offers a

large potential gain.

With the wider beam, the need for bal-

last water for stability is eliminated for

most loading conditions. However, the

trim and longitudinal bending moment

may be an issue for some conditions,

depending on the weight distribution of

the containers.

In principle, the trim and bending mo-

ment can be controlled by using an

intelligent loading system, hence dis-

tributing the weight properly in the lon-

gitudinal direction. In this case, ballast

water is not needed, which means that

fuel can be saved and ballast water

treatment can be avoided.

Due to logistics, it may not always be

possible to load the ship in the preferred

manner, and ballast water may then be

needed. However, also in the design

phase there are options for reducing the

need for ballast water for trimming and

bending moment reduction:

1. The shorter and wider ship has a

smaller bending moment compared

with the longer ship, for a compa-

rable loading condition. Hence, the

need for ballast water to control the

bending moment is reduced.

2. By increasing the design draught, the

ship will have more buoyancy in the

fore and aft part. This also contributes

to reducing the bending moment, and

reducing the need for ballast water.

3. By using a twin-island arrangement,

as shown in Fig. 40, the ship will have

a more even loading of containers,

which gives a more beneficial trim. In

addition, the sightline is better, both

of which reduce the need for ballast

water for trimming purposes. A tra-

ditional single-island container ship

comparison resulted in a 20% reduc-

tion in ballast water for homogene-

ous loading conditions.

4. In addition, modifying the hull lines

to change the longitudinal centre of

flotation, may give a better trim char-

acteristics. However, this may lead

to a larger wave resistance. The two

effects need to be weighed against

each other to determine the opti-

mal hull shape. For Quantum 9000,

it was found that there is a penalty

in moving the LCB away from the

original location for all the conditions

where ballast water is not required to

achieve the required trim. The added

hull resistance varies according to

the loading condition and speed, but

it can be up to 5%. As a result, mov-

ing the LCB aft, to reduce the need

for ballast water, would not be ben-

eficial for this project.

The actual cost of carrying ballast wa-

ter with respect to added engine power

needed has been investigated. The

study showed that carrying 5000 tons,

in average, of extra ballast water could

potentially increase the fuel bill by about

USD 250,000 annually. Furthermore,

there would be additional costs related

to the ballast water treatment system.Fig. 40: Loading condition example

32 Quantum 9000

Propeller Optimisation

In general, a large propeller diameter

(and low rpm), low blade area ratio and

fewer blades, give a high efficiency. In

this respect, it has been considered that

the lowest engine speed available at the

optimising point is about 75 rpm.

The lowest possible blade area ratio is

chosen using the Burril/Keller criteria,

which in general ensures an acceptable

cavitation performance.

The operating data for the propeller is

as follows:

Optim. point MCRShip speed: 22 knots Abt. 23 knotsEngine power: 32 MW 41 MW

Engine speed: 75 rpm 78 rpm

Compared with many other container

ships, the optimising point for this pro-

peller corresponds to a relatively low

propeller loading. Also, a somewhat

higher propeller-induced noise and aft

ship vibration will be acceptable com-

pared to reference ships because of the

location of the superstructure.

An optimising procedure, evaluating

propellers with 4, 5, and 6 blades result-

ed in the following propeller alternatives:

Blades: 4 5 6

Optimum diameter: 10.0 m 9.6 m 9.2 m

Open water efficiency: 0.671 0.664 0.659

Necessary blade area ratio: 0.50 0.57 0.63

Pitch ratio: 0.94 1.00 1.08

Based on the above, a preliminary de-

sign was worked out for the 4-bladed

propeller alternative, which results in the

highest efficiency. Additional (indicated)

main data for the 4-bladed propeller ar-

rangement is as follows:

Propeller blade skew angle: 35 deg.Propeller shaft diameter: 0.90 mHub diameter: 1.6 mHub length: 1.8 mPropeller weight: 102 ton

(scantlings acc. to DNV rules)

The propeller weight is about 9% lower

than for a 6-blade propeller.

The quite highly skewed propeller is ex-

pected to ensure a reasonable level of

pressure pulses (mainly 1st order blade

frequency) transmitted into the hull, tak-

ing the relative propeller loading into

consideration.

The influence of the propeller on the aft

stern tube bearing working conditions

has been considered, based on expe-

rience, and found to be manageable,

with respect to both nominal bearing

load, the load distribution in bearing,

and the possible load dynamics (mainly

at blade frequency).

Cost-benefit Calculations Cost-benefit assessment

The economic performance of the ship

concept should be evaluated by com-

paring the additional investment costs

against the future savings, as com-

0.645

0.650

0.655

0.660

0.665

0.670

0.675

8.8 9.0 9.2 9.4 9.6 9.8 10.0 10.2 10.4 10.6 10.80.20

0.40

0.60

1.80

1.00

1.20

1.40

11.0

Area and Pitsh ratiosEfficiency

Propeller diameter (m)Efficiency, 6 BladesEfficiency, 4 Blades

Area ratio, 6 BladesArea ratio, 4 Blades

Pitch ratio, 6 BladesPitch ratio, 4 Blades

Fig. 41: Propeller efficiency vs. diameter – diagrams

Fig. 42: Propeller design (illustrative)

MAN B&W Diesel33Quantum 9000

pared with a conventional ship. Future

savings have been calculated by con-

sidering different fuel price scenarios.

Two reference scenarios for fuel price

development have been considered, as

shown in Fig. 43 and Fig. 44. In addi-

tion, the performance is measured in

terms of the energy efficiency design

index (EEDI). Fig 46 shows that the

proposed concept has a very low EEDI

value compared with the baseline. This

is mainly the result of the use of LNG

as fuel, combined with waste heat re-

covery, reduced speed, and optimal

hull form.

The payback time shown in Fig. 45 for

the additional investments is very sen-

sitive to the future fuel prices. For the

gas main engine, with LNG tanks and

fuel supply system, the payback time

will be 5-10 years depending on the

fuel price development. For the dual

fuel auxiliary engines, the payback time

is shorter, because it is assumed that

the LNG tanks and system are already

in place for the main engine. For the

waste heat recovery system and shaft

generator, the payback time is between

7 to 10 years. An improved hull shape

and arrangement has a relatively low

additional investment cost and a short

payback time.

It should be emphasised that the cost

estimates for LNG tanks and systems,

and for the WHR, are based on today’s

prices, which are a result of relatively

low production volumes. It is expected

that the cost of these systems could be

significantly reduced in the future, when

more gas-fuelled ships are built and

the production volume of the systems

becomes larger. Especially on the LNG

tank side, it is expected that many new

tank types will get on the market and

press prices down.

It is also important to notice that the LNG

prices include some additional cost for

distribution, but this will be very much

dependent on the future LNG bunkering

infrastructure, way of bunkering, loca-

tion of bunkering, etc. It is assumed that

LNG will be delivered from large-scale

LNG terminals, so that expensive small-

scale production of LNG is avoided.

0

200

400

600

800

1,000

1,200

1,400

2011

2012

2013

2014

2015

2016

2017

2018

2019

2020

2021

2022

2023

2024

2025

2026

2027

2028

2029

2030

2031

2032

2033

2034

2035

2008$/tonne

Residual Fuel Price Distillate fuel Natural gas (per metric tonne)

Fig. 43: US EIA Annual Energy Outlook 2010: reference scenario

0

500

1,000

1,500

2,000

2,500

2011

2012

2013

2014

2015

2016

2017

2018

2019

2020

2021

2022

2023

2024

2025

2026

2027

2028

2029

2030

2031

2032

2033

2034

2035

2008$/tonne

Residual Fuel Price Distillate fuel Natural gas (per metric tonne)

Fig. 44: US EIA Annual Energy Outlook 2010: high scenario

34 Quantum 9000

Conclusion

The Quantum 9000 concept demon-

strates the commercial viability of vessel

optimisation using a realistic trading pro-

file and operational characteristics. The

Quantum 9000 ship design has been

through iterative optimisation processes

to achieve improved performance, par-

ticularly concerning the hull profile and

propeller design. And a twin-island de-

sign is chosen for maximum container

capacity. In addition to optimisation of

0

5

10

15

20

25

Hull andcargo

LNG engine,system and tank

Dual auxengines

Waste heatrecovery

Shaftgenerator

Years Pay back time, 8% discount rate

High price scenario Reference scenario

Fig. 45: Calculated pay back time of additional investments, with 8% discount rate

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

0 50.000 100.000 150.000 200.000

Grams per tonne*nm

Dwt

Container(>=400 gt, built 1998-2007)

Baseline samples IMO EEDI Baseline Quantum 9000

Fig. 46: Calculated Energy Efficiency Design Index (EEDI)

design parameters, the study has includ-

ed practical information relating to vessel

operation such as bunkering of LNG and

class requirements.

The chosen MAN B&W two-stroke dual

fuel ME-GI engine further enhances the

desirability of the Quantum 9000, by in-

troducing a degree of fuel flexibility pre-

viously unexploited by industry. In these

times of fuel price volatility, the ME-GI

should be considered to mitigate the risk.

Furthermore, the use of LNG as a fuel

has the environmental benefit of reduced

emissions, which plays an increasingly

important role in the selection of the type

of transportation of goods.

The cost benefit analysis of five different

investments shows that each investment

will increase the profitability of the vessel

over its 25-year lifetime, both in the refer-

ence and in the high HFO price scenario,

and it should therefore be of the utmost

interest to shipowners.

References

[1] Two-stroke Low Speed Diesel En-

gines – for Independent Power Pro-

ducers and Captive Power Plants

[2] DNV Rules Pt.6 Ch.13 Gas fuelled

engine installations

[3] IMO Res. MSC.285(86); Interim

Guidelines on safety for natural gas-

fuelled engine installations in ships

MAN Diesel & TurboTeglholmsgade 412450 Copenhagen SV, DenmarkPhone +45 33 85 11 00Fax +45 33 85 10 30info-cph@mandieselturbo.comwww.mandieselturbo.com

MAN Diesel & Turbo – a member of the MAN Group

All data provided in this document is non-binding. This data serves informational purposes only and is especially not guaranteed in any way. Depending on the subsequent specific individual projects, the relevant data may be subject to changes and will be assessed and determined individually for each project. This will depend on the particular characteristics of each individual project, especially specific site and operational conditions. Copyright © MAN Diesel & Turbo. 5510-0108-01ppr Aug 2012 Printed in Denmark