Download - Wartsila 32
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
8
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.
10
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.
13
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.
14
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.
15
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.
16
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.
17
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.
18
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.
19
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.
20
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.
21
MainTechnical Data
22
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
23
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
01E
/B
ock´s
Off
ice
/A
rkm
ed
ia