Today’s shipping business is faced with the

requirement to reduce fuel oil consumption

throughout the fleet’s operating profiles. Similarly,

operational reliability and vessel availability

must be ensured, maintenance costs need to

be reduced, and emissions legislation has to be

complied with.

Wärtsilä’s Intelligent Combustion Control

system (ICC) supports to achieve all these goals.

It enables the ship’s engines to operate reliably

and in accordance with their original shop test

performance. This is done automatically on board,

in real time and regardless of the fuel in use or

ambient conditions.

The ICC system automatically balances

compression and firing pressures in all cylinders,

resulting in equal exploitation of each unit and

reduced torsional vibrations of the complete

engine. The system also protects the engine

against potential manual operating errors.

The advantages of the system become even

more significant when the fuel has to be changed

while in SOX Emission Control Areas, and always

when different fuel qualities are used for cost or

availability reasons.

Compared to an engine where the Fuel

Quality Setting (FQS) is not adjusted properly, the

measured reduction in fuel oil consumption with

an activated ICC is up to 2.5 g/kWh over the whole

engine load range. When ICC is active the specific

fuel oil consumption is reduced which results in a

decrease of CO2 emissions.

ICC benefIts • Optimized fuel consumption over whole load

range

• Reduced maintenance costs and downtime

• Fully automated balancing

• Real-time data

• Reduced workload for crew and technical

department

• Maximized availability and reliability through a

safer, finely balanced engine operation

INTELLIGENT COMBUSTION CONTROL FOR WÄRTSILÄ TWO-STROKE RT-flex ENGINES

a WeCs-9520 optIonThe ICC system is an optional part of WECS-

9520 (Wärtsilä Engine Control System),

which adjusts the peak fi ring pressure of the

engine according to the given design criteria.

The fi ring and compression pressures of

all cylinders are balanced by adjusting the

injection timing and exhaust valve closing

within their allowed operating range. All

modifi cations of engine control parameters

made in the ICC system are compliant with

the vessel’s IMO certifi cate.

The ICC system also limits the pressure

rise (compression/ combustion ratio) of the

engine as an included safety function. This

reduces the wear of engine components,

minimizes the risk of overloads, and helps

to avoid manual adjustment fl aws in case of

open loop control.

Thanks to the ICC system, the engine is

always operated according to its design criteria,

as safely and as effi ciently as possible.

InstallatIon referenCeAfter the completion of rigorous testing,

the ICC system was installed on two

vessels powered by Wärtsilä 7RT-fl ex96C

and 12RT-fl ex96C engines. The complete

installation took place during port time, and

the ICC system was commissioned during

a short voyage between European ports

without infl uencing the vessel’s schedule.

Commissioning included functionality and

performance testing.

0

25

50

75

125

100

60 70 80 90 100 110

Load

[%]

Speed [%]

operating range of ICC

30 40 50 60 70 80

SFO

C [g

/kW

h]

Load [%]

SFOC measurements on board

OPEN LOOP (FQS=0)

CLOSED LOOP (ICC)

figure 1: sfoC measurement on board.

80

90

100

110

120

130

140

30 40 50 60 70 80

P_M

AX

[bar

]

Load [%]

ISO corrected Firing Pressure

OPEN LOOP (FQS=0)

CLOSED LOOP (ICC)

figure 2: Iso corrected fi ring pressure.the compression and fi ring pressures are adjusted with ICC for each engine speed / load operating point.

62

62,5

63

63,5

64

64,5

65

65,5

66

0 20 40 60 80 100 120Compression Pressure Cyl. 1 Compression Pressure Cyl. 2 Compression Pressure Cyl. 3Compression Pressure Cyl. 4 Compression Pressure Cyl. 5 Compression Pressure Cyl. 6Compression Pressure Cyl. 7 Compression Pressure Average

-COMPRESSION PRESSURE CLOSED LOOP CONTROL ON

Com

pres

sion

Pre

ssur

e (b

ar)

time (sec)62

62,5

63

63,5

64

64,5

65

65,5

66

0 20 40 60 80 100 120Compression Pressure Cyl. 1 Compression Pressure Cyl. 2 Compression Pressure Cyl. 3Compression Pressure Cyl. 4 Compression Pressure Cyl. 5 Compression Pressure Cyl. 6Compression Pressure Cyl. 7 Compression Pressure Average

COMPRESSION PRESSURE - OPEN LOOP CONTROL

Com

pres

sion

Pre

ssur

e (b

ar)

time (sec)

Closed Loop control OFF Closed Loop control ON

Average of Pcomp

92

94

96

102

104

0 20 40 60 80 100 120Firing Pressure Cyl. 1 Firing Pressure Cyl. 2 Firing Pressure Cyl. 3Firing Pressure Cyl. 4 Firing Pressure Cyl. 5 Firing Pressure Cyl. 6Firing Pressure Cyl. 7 Firing Pressure Average Firing Pressure Setpoint

time (sec)

-FIRING PRESSURE CLOSED LOOP CONTROL

92

94

96

98

100

102

104

0 20 40 60 80 100 120Firing Pressure Cyl. 1 Firing Pressure Cyl. 2 Firing Pressure Cyl. 3Firing Pressure Cyl. 4 Firing Pressure Cyl. 5 Firing Pressure Cyl. 6Firing Pressure Cyl. 7 Firing Pressure Average Firing Pressure Setpoint

-FIRING PRESSURE OPEN LOOP CONTROL

Firi

ng P

ress

ure

(bar

)

time (sec)

Closed Loop control OFF Closed Loop control ON

Cyl. average PMax

Setpoint

figure 3: activation of ICC (Wärtsilä 7rt-fl ex96C).Compression and fi ring pressure deviations between cylinders are clearly reduced.

Compared to the original setting with

standard Open Loop Control and FQS=0, a

fuel oil consumption reduction was observed

for each operating point (fi gure 1). This was

achieved mainly with the adjustment to

the permitted peak fi ring pressure at each

speed / load point with activated Closed

Loop Control (fi gure 2).

the WärtsIlä ICC solutIon provIdes safer operatIon WIth reduCed CostsOptimized engine operation

• Fuel savings up to 2.5 g/kWh

• Automated FQS setting

Balanced mechanical and thermal load

distribution

• Automated adjustment of compression and

firing pressures

• Reduced wear and ageing of sensitive

engine components

• Prevention of mechanical and thermal

overload (high-peak pressures)

• Avoidance of unfavourable manual FQS

adjustment

ConClusIonICC ensures that the engine is operated

according to its design criteria, as safely and

as efficiently as possible. The reduction in fuel

oil consumption with an activated ICC is up to

2.5 g/kWh over the whole engine load range.

The equal exploitation of each cylinder unit of

the engine by the balancing of compression

and firing pressure reduces potential

overload and abnormal wear rates of engine

components. The ICC system helps to reduce

the work load of the crew as all adaptations

and adjustments are done automatically while

also considering fuel quality and ambient

conditions.

WARTSILA.COM

WÄRTSILÄ® is a registered trademark. Copyright © 2011 Wärtsilä Corporation. Specifications are subject to change without prior notice.