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Machinery Auxiliary Systems
Cooling systems
Heat from diesel engine and auxiliary units is directly or
indirectly dissipated to sea water. Exceptions are exhaust
gas and radiation.
Temperature control is important
• Wide variation of the cooling energy demand.
• Wide variation of sea water temperature
• Engine sensitivity to temperature deviations
• Preferably independent systems for ME’s (2x) and AE’s for
simple adjustment
Water flow can be prevented by air pockets, ice slush or
entered material.
Chemical purity is important
Pentti Häkkinen ER auxiliaries 9.2.
Wärtsilä New Professionals 3.-7.11.2008
Cooling Systems
Cooling energy distribution at various load
Radiation
Fuel energy
100%
1%
Mechanical
energy
47%
Exhaust gas
26 %
Exhaust gas
heat recovery
can increase
the produced
mechanical
energy 3%
Cooling water
loss 26%
Pentti Häkkinen ER auxiliaries 9.2.
Wärtsilä New Professionals 3.-7.11.2008
LT Cooling System
Air evacuation, expansion tk
Throttle Gear cooler Other coolers
HT water
cooler
Lub oil
cooler
Air cooler
II stage
Bypass
line for
low load
Therm. valve Central coolers
Pentti Häkkinen ER auxiliaries 9.2.
Wärtsilä New Professionals 3.-7.11.2008
Sea Water Cooling System
Components
Low and high sea chests:
Volume in GA drawings. 1m3 /750kW.
Not necessarily on opposite sides.
Sea water main line:
Cunifer or rubber coated steel pipe
ND250 … 600 or duct in double bottom,
often in the very crowded area
Central coolers:
2 easily cleaned titanium plate coolers
Main sea water pumps:
SW and ballast pumps directly above
SW main line
Pentti Häkkinen ER auxiliaries 9.2.
Wärtsilä New Professionals 3.-7.11.2008
Sea Water Cooling System
Central coolers
3-way valve
Air pipe
Non-return
valve
S.W. pump
Side valve
Intake Filter Temper. Main SW Isolation Double
grating basket sensor line
valve
bottom
Pentti Häkkinen ER auxiliaries 9.2.
Wärtsilä New Professionals 3.-7.11.2008
Ice
sea chest
(which is
extending
above CWL)
Sea Water Cooling System
Sea water and
fresh water cooling pumps
Main sea water cooling
line, mixing valve and filter
Pentti Häkkinen ER auxiliaries 9.2.
Wärtsilä New Professionals 3.-7.11.2008
Sea Water Cooling Systems
Alternatives
Box cooler, good operation
record in smaller ships
Vent pipe
Shelter plate
Shallow (H= 100 mm)
tank against bottom
plate. Internal baffle
plates promote the
heat transfer
Bolted
flange
Cleaning
air feed
Inlet grid
Pentti Häkkinen ER auxiliaries 9.2.
Wärtsilä New Professionals 3.-7.11.2008
Keel cooler, used in
Mississippi muddy
waters, in river boats
Outlet grid
Position of Cooling System & Air Units
LT, SW pumps
Sea water pumps
High sea chest
Central coolers
Lub oil coolers
Low sea chest
Pentti Häkkinen ER auxiliaries 9.2.
Wärtsilä New Professionals 3.-7.11.2008