Technology Review

2

This is a brief guide to the technical features and

advantages of the new Wärtsilä 32 engine.

Design Philosophy

4

Low NOx Combustion 5

Crankshaft and Bearings 6

Engine Block 7

Piston 8

Piston Rings 9

Cylinder Liner and Anti-polishing Ring 10

Connecting Rod 11

Cylinder Head 12

Multiduct 13

Fuel Injection System 14

Turbocharging System 15

Cooling System 16

Lubricating Oil System 17

Automation System 18

Easy Application 19

Easy Maintenance 20

3

TechnologyReview

DesignPhilosophy

The Wärtsilä 32 is based on the latest achievements in

combustion technology; it is designed for flexible manufacturing

methods and long maintenance - free operating periods. The

engine is fully equipped with all essential ancillaries and a

thoroughly planned interface to external systems. The main

qualities of the Wärtsilä 32 are:

• Low NOx combustion

• Reliability and low maintenance costs

• Integrated monitoring and control

• Ergonomic interface

• Minimal consumables

4

Low NOx

Combustion

Hydrocarbons can be burnt under a wide range of conditions. To

burn them efficiently with the lowest possible emissions, in

particular of NOx, Wärtsilä NSD developed a Low NOx

combustion process which reduces the NOx level by up to 50 %

without compromising on thermal efficiency.

Low NOx combustion is based on:

• A higher combustion air temperature at the start of injection,

which drastically reduces the ignition delay

• A late start of injection and shorter injection duration to place

combustion at the optimal point of the cycle with respect to

efficiency

• Improved fuel atomization and matching of combustion space

with fuel sprays to facilitate air and fuel mixing.

5

Low NOx design

Engine maximum firing pressure

Pressure rise

induced from

combustion

TDC

Cylinder

pre

ssure

Conventional design

Engine maximum firing pressure

Pressure rise

induced from

combustion

TDC

Cylinder

pre

ssure

-90 -60 -30 0 30 60 90 120 -90 -60 -30 0 30 60 90 120

Incre

ase

of

SFO

C(%

)

Relative NOx emission (%)

50 60 70 80 90 100

Conventional low NOx modifivation

State-of-the-art

Modification according to the "low NOx combustion" concept

0

1

2

3

4

5

6

7

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Crankshaftand Bearings

The latest advance in combustion development require a crank

gear which can operate reliably at high cylinder pressures. The

crankshaft must be robust and the specific bearing loads kept at

an acceptable level.

This is achieved by careful optimisation of crankthrow

dimensions and fillets. The specific bearing loads are conservative

and the cylinder spacing, which is important for the overall length

of the engine, is minimised.

Besides low bearing loads, the other crucial factor for safe

bearing operation is oil film thickness. Ample oil film thicknesses in

the main bearings are ensured by optimal balancing of rotational

masses and in the big end bearing by ungrooved bearing

surfaces in the critical areas. All the factors needed for a free

choice of the most appropriate bearing material are present.

6

Fully MachinedConnecting Rod

EngineBlock

Thanks to its strength and stiffness properties, together with all

the freedom offered by carting, nodular cast iron is the natural

choice for engine blocks today. The Wärtsilä 32 makes optimum

use of modern foundry technology to integrate most oil and water

channels. The result is a virtually pipe-free engine with a clean

outer exterior.

Resilient mounting is state-of-the-art in many applications

and requires a stiff engine frame. By Integrated channels

designed with this in mind can serve double purposes.

7

ThePiston

For years, the outstanding piston concept for highly rated heavy

fuel engines has been a composite piston with a steel crown and

nodular cast-iron skirt. More than fifteen years of experience has

fine-tuned the concept. When it comes to reliability, there is no

real alternative today for modern engines with high cylinder

pressures and combustion temperatures. Wärtsilä NSD-patented

skirt lubrication is applied to minimise frictional losses and ensure

appropriate lubrication of both piston rings and the piston skirt.

8

ThePiston Rings

In Wärtsilä NSD´s three-ring concept each ring has a specific

task. They are dimensioned and profiled for consistent

performance throughout their operating lives. To avoid carbon

deposits in the ring grooves of a heavy fuel engine, the pressure

balance on top of and underneath each ring is crucial. Experience

has shown that this effect is most likely achieved with a three-ring

pack. Finally, it is well known that most frictional losses in a

reciprocating combustion engine originate from the rings. Thus a

three-ring pack is the obvious choice in this respect, too. The top

ring, which bears the greatest load, is provided with an special

wear- resistant coating.

9

Cylinder Liner andAnti-polishing Ring

The thick high-collar type cylinder liner is designed to have the

stiffness needed to withstand both pre-tension forces and

combustion pressures with virtually no deformation. Its

temperature is controlled by bore cooling of the upper part of the

collar to achieve a low thermal load and to avoid sulphuric acid

corrosion. The cooling water is distributed around the liners with

simple water distribution rings at the lower end of the collar. In the

upper end the liner is equipped with an anti-polishing ring to

eliminate bore polishing and reduce lube oil consumption. The

function of this ring is to calibrate the carbon deposits formed on

the piston top land to a thickness small enough to prevent any

contact between the liner wall and the deposits at any piston

position. When there is no contact between the liner and piston

top land deposits it is obvious that no oil can be scraped upwards

by the piston. The other positive effect is that the liner wear is

significantly reduced at the same time.

The strength of the wear-resistant liner materials used for

years in Wärtsilä NSD engines has been further increased to cope

with the high combustion pressures expected in the future.

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ConnectingRod

A three-piece connecting rod with all the highly stressed surfaces

machined is the safest design for engines of this size intended for

continuous operation at high combustion pressures. For easy

maintenance and accessibility the upper joint face is placed right

on top of the big-end bearing housing. A special hydraulic tool is

developed for simultaneous tensioning of all four screws.

To eliminate any risk of wear in the contact surfaces, an

intermediate plate with a special surface treatment is placed

between the main parts.

11

CylinderHead

The cylinder head design is based on the four- screw concept

developed by Wärtsilä NSD and used for more than 15 years. Its

internal structure is designed for maximum stiffness, which is

essential for obtaining both liner roundness and even contact

between exhaust valves and their seats.

A four-screw cylinder head design also provides all the freedom

needed for designing inlet and exhaust ports with a minimum of

flow losses. Computational fluid dynamics (CFD) analysis in

combination with full-scale flow measurements has been used for

port design optimization.

The vast amount of experience gained from heavy fuel

operation all around the world has centributed greatly to exhaust-

valve design and development. Put together, this means that a

valve material and geometry with superior performance is now

available.

12

TheMultiduct

Multiducts replace a number of individual components in

traditional engine designs. Their functions are:

• Air transfer from the air receiver to the cylinder head

• Exhaust transfer to the exhaust system

• Cooling water outlet after the cylinder head

• Cooling water return channel from the engine.

• Additional functions are:

• Introduction of an initial swirl to the inlet air for optimal part

load combustion

• Insulation / cooling of the exhaust transfer duct

• Support for exhaust system and its insulation.

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Fuel InjectionSystem

The ultimate safety in low pressure fuel system design is achieved

with the Wärtsilä NSD- patented multihousing principle. With this

system the fuel line consists basically of drilled channels in cast

parts clamped firmly on the engine block. In Wärtsilä 32 these

parts are

• the pump housing

• the tappet housing

• the fuel transfer housing

• the multicover.

For easy assembly/disassembly these parts are connected to

each other with slide connections. Since both the whole low-

pressure system and the high-pressure system are housed in a

fully covered compartment, the safety standard is unbeatable.

The high pressure system was designed and endurance tested at

2000 bar. Injection pressure is around 1800 bar.

With a wear-resistant low-friction coating on the plunger no

lubricating oil is required for the pump element. Thanks to the

profiled plunger geometry the clearance between plunger and

barrel can be kept small, thereby allowing only a minimum of oil to

pass down the plunger. This small leakage is collected and

returned to the fuel system. Any likelihood of the fuel mixing with

the lube oil is eliminated. Both nozzle holders and the nozzle are

made of high-grade hardened steel to with stand the high

injection pressures. Combined with oil cooling of the nozzles this

guarantees outstanding nozzle lifetimes.

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Nozzle cooling oil

TurbochargingSystem

Every Wärtsilä 32 engine is equipped with the turbocharging

system that best fulfils the requirements of each specific

application.

The standard options are

• pulse system

• SPEX system

• SPEX system with exhaust wastegate and air by-pass.

The system is designed for minimum flow losses on both

exhaust and air sides.

The interface between engine and turbocharger is streamlined

to avoid all the adaption pieces and piping frequently used in

the past. Non-cooled chargers with inboard plain bearings

lubricated from the engine´s lube oil system are used.

All this makes for longer intervals between overhauls

and reduced maintenance.

The turbocharger technology is going through a

period of intense design and performance development.

Only the best available charger technology will be used on

the Wärtsilä 32.

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Exhaust waste-gate and air bypass

Pulse charging

SPEX charging

CoolingSystem

The cooling system is split into two separate circuits, the high

temperature (HT) and the low temperature (LT) circuits. The

cylinder liner and the cylinder head temperatures are controlled

through the HT circuit. The system temperature is kept at a high

level, about 95 °C, for safe ignition/combustion of low quality

heavy fuels, also at low loads. An additional advantage is

maximum heat recovery and total efficiency in cogeneration

plants. To further increase the recoverable heat from this circuit it

is connected to the high-temperature part of the double-stage

charge air cooler. The HT water pump and thermostatic valve are

integrated with the “ pump cover module” at the free end of the

engine. The complete HT circuit is thus virtually free of pipes.

The LT circuit serves the low-temperature part of the charge

air cooler and the built-on lube oil cooler. It is fully integrated with

engine parts such as the LT water pump with pump cover

module, the LT thermostatic valve with the lube oil module and

transfer channels in the engine block.

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Engine

62–70 °C73–80 °C

Charge aircooler

Lube oilcooler

Exp.0.7–1.5 bar

Exp.0.7–1.5 bar

35–45 °C65–70 °C

LTCcentralcooler

93–97 °C

HTCcentralcooler

Engine

Pre-heater

Lubricating OilSystem

All Wärtsilä 32 engines are equipped with a complete lube oil

system, i.e. an engine-driven main pump, electrically driven

prelubricating pump, cooler, full flow filter and centrifugal filter.

The engine may also be fitted with special running-in filters before

each main bearing. The pumps, pressure regulation and safety

valves are integrated into one module fitted at the free end of the

engine. Filter, cooler and thermostatic valves make up another

module. On in-line engines this is always located neatly at the

engine backside whereas on V-engines it is either at the flywheel

or free end, depending on the turbocharger position.

The lube oil filtration is based on an automatic back-flushing filter

requiring a minimum of maintenance. The filter elements are

made of seamless sleeve fabric with high temperature resistance.

An overhaul interval of one year is recommended. The expected

lifetime is four years. A special feature is the centrifugal filter,

connected to the back-flushing line of the automatic filter. This

provides the means for extraction of distant wear particles from

the system.

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FilterCooler Pump

Primingpump

Lube oil system

AutomationSystem

An engine-integrated automation system, WECS, is standard on

Wärtsilä 32. Optimum use of this technology greatly simplifies

both the wiring on the engine and the whole installation. The

system has the following main components:

• The Main Control Unit (MCU) Cabinet,which comprises the

MCU itself, a relay module with back-up functions, a Local

Display Unit (LDU), control buttons and back-up

instruments.The MCU handles all communication with the

external system.

• The Distributed Control Unit (DCU) handling signal transfer over

a CAN bus to the MCU.

• The Sensor Multiplexing Units (SMU) transferring sensor

information to the MCU.

The software loaded into the system is easily configured to match

the instrumentation, safety and control functions required for each

installation. For maximum safety, the durability of all components

is ensured by selecting only the best available; it is verified by

stringent testing. Thus temperature resistance, vibration

resistance and electromagnetic compatibility are guaranteed.

Because a diesel engine must sometimes endure pretty

rough handling the MCU cabinet is well protected and built into

the engine. The same goes for the rest of the hardware, most of

which is housed in a special electrical compartment alongside the

engine.

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WECS cabinet

To external systems

SMU

DCU

MCU and display unit Display

Display selection buttons

Backup instruments

Local control buttons

DCU unit

EasyApplication

An important design principle of the Wärtsilä 32 is to build as

much auxiliary equipment as possible on the engine. This goes for

lube oil and water pumps, lube oil cooler and filter, engine control

and monitoring. Application work is thus reduced to a minimum.

However, the engine still needs connections to external systems.

The trend is increasingly towards standardized modules. To make

full use of this from an installation cost point of view, the engine

should support smooth interfacing. The Wärtsilä 32 comes in a

number of standard options, e.g. a turbocharger at either end of

the engine and one or two-stage charge air cooling, without

sacrificing the easy interfacing principle.

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EasyMaintenance

Efficient and easy maintenance is incorporated into the design. In

combination with the long intervals between overhauls, the hours

spent on maintenance are reduced to a minimum. The lube oil

filtration is one good example. Hydraulics are used for pre-tension

of the cylinder head screws, all the connecting rod screws, and

the main bearing screws. The distinctive Wärtsilä feature with

individual hydraulic jacks for each main bearing is of course

adopted. The unique fuel line design enables injection pump

exchange with a minimum of work with less risk of error.

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The multiduct arrangement allows the cylinder head to be lifted

without removal of water pipes and the slide-in connections on

the manoeuvring side allows it to be lifted without removal of oil or

air pipes. The water pumps are easy to replace thanks to the

cassette design principle and water channel arrangement in the

pump cover at the free end of the engine. There is greater

accessibility to all the above-mentioned components thanks to a

minimal number of pipes and an ergonomic component design.

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MainTechnical Data

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Main Data

Cylinder bore 320 mm

Piston stroke 400 mm

Speed 720 - 750 rpm

Mean effective pressure 23.3 - 22.9 bar

Piston speed 9.6 - 10.0 m/s

FUEL SPECIFICATION:

Fuel oil 730 cSt/50°C

7 200 sRI/100°F

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Rated power: Propulsion engines

Engine

type

Output

720 rpm 750 rpm

kW BHP kW BHP

6L32

8L32

9L32

12V32

16V32

18V32

2 700

3 600

4 050

5 400

7 200

8 100

3 670

4 890

5 510

7 340

9 790

11 010

2 760

3 680

4 140

5 520

7 360

8 280

3 750

5 000

5 630

7 510

10 010

11 260

Principal engine dimensions (mm) and weights (tonnes)

Engine

typeA B C D E F Weight ton

6L32

8L32

9L32

12V32

16V32

18V32

5 110

6 405

6 895

6 868

8 206

8 766

2 553

2 806

2 806

2 680

2 910

2 910

2 207

2 207

2 207

2 920

3 296

3 296

2 345

2 345

2 345

2 080

2 080

2 080

500

500

500

650

650

650

1 150

1 150

1 150

1 472

1 472

1 472

32

42

48

55

67

75

Rated power: Generating sets

Engine

type

Output

720 rpm/60 Hz 750 rpm/50 Hz

Engine kW Gen. kW Engine kW Gen. kW

6L32

8L32

9L32

12V32

16V32

18V32

2 700

3 600

4 050

5 400

7 200

8 100

2 600

3 470

3 900

5 210

6 940

7 810

2 760

3 680

4 140

5 520

7 360

8 280

2 660

3 550

3 990

5 320

7 100

7 990

Principal genset dimensions (mm) and weights (tonnes)

Engine

typeLength Width Height Genset weight

6L32

8L32

9L32

12V32

16V32

18V32

8 980

10 090

10 580

10 053

11 621

12 381

2 330

2 730

2 730

3 060

3 360

3 360

4 003

4 426

4 426

4 572

4 802

4 802

56

73

79

90

107

117

Wärtsilä NSD Corporation is a global engineering company

focusing on marine propulsion, power generation and industrial

applications. Wärtsilä NSD designs, manufactures, licenses,

markets and services Wärtsilä and Sulzer engines from

0.5 to 66 MW (700 to 90,000 bhp). The company engineers and

provides complete propulsion systems for all vessel types and

turnkey power plants from 1 to 400 MW.

With its global sales and service network and licensees in all

major markets, Wärtsilä NSD is your local partner who can

deliver the optimum solution to meet your present and future

power needs.

Wärtsilä NSD Finland Oy

P.O.Box 252

FIN-65101 Vaasa, Finland

Telephone +358-6-3270

Fax Marine +358-6-356 7188

Fax Power Plants +358-6-356 9133 WN

S98M

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