1. 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

2. Cooling energy distribution at various load
Cooling Systems
Cooling energy distribution at various load
Radiation Mechanical energy % %
Exhaust gas 26 %
Fuel energy 100%
Exhaust gas heat recovery can increase the produced mechanical energy 3%
Cooling water loss 26%

3. Cooling energy distribution at various load
Cooling systems
Cooling energy distribution at various load
80 80
60 60
40 40
20 20
Radiation
Heat flow relative to full power %
Exhaust gas
Cooling
Charge air
Power along propeller law

4. Cooling Systems LT and HT systems
HT = high temperature
LT = low temperature
HT water can be cooled either in coolers by LT or SW or by mixing with LT (preferred method).
LO cooler
Central cooler
Air cooler I II
LT circuit is often common but each engine has its own LT pumps.
Each engine has its independent HT circuit and pump. Preheating line is connecting engines.

5. HT Cooling System Throttle flange in gravity tank line Temper. sensor
Fresh water generator
Preheater
Separate HT cooler
Thermostatic mixing valve
Thermostatic bypass valve

6. 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

7. Direct driven pumps Direct driven cooling water pumps
Direct driven lubrication oil pump

8. 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

9. Sea Water Cooling System
Central coolers Air pipe
Ice sea chest (which is extending above CWL)
3-way valve
Side valve
Non-return valve
S.W. pump
Intake Filter Temper. Main SW Isolation Double grating basket sensor line valve bottom

10. Sea Water Cooling System
Sea water and fresh water cooling pumps
Main sea water cooling line, mixing valve and filter

11. Sea Water Cooling Systems
Alternatives
Box cooler, good operation record in smaller ships
Keel cooler, used in Mississippi muddy waters, in river boats
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 Outlet grid

12. Position of Cooling System & Air Units
LT, SW pumps Sea water pumps
High sea chest
Central coolers
Lub oil coolers
Low sea chest
Start. air vessels & compressors

13. Starting Air System General Location Main components Design problems
Common 30 bar system for main and auxiliary engines. Control air and work tool air 7 bar systems may be integrated in simple ships.
Location
In engine room (redundant engine rooms). Receivers can be stowed on wall.
Main components
Duplicate compressors and air receivers, separate receiver for aux. engines. For low speed engines compressor motor 2 * 50kW, air receivers 2 *10m3.
Design problems
Very seldom
Operation problems
Neglected draining, water or air accumulation. Explosion risk

14. Starting Air System (simple version)
Tools on deck Pressure reduction Typhoon To aux. engines
To exhaust gas boiler soot blowing
High pressure line to main engine starting
Air inlet valve controlled by low pressure air
Safety valve
Water drain
Pressure reduction Filter Main compressors

15. Engine Room Ventilation System
Inlet blowers
2 … 4 in main engine room. Often 1 … 2 are reversible / 2 speed motors. Total capacity is engine nominal air consumption + 70 … 100%
Free air exhaust through engine casing
Exhaust blowers & ducts from purifier room & other oil mist areas
Channels: round fabricated ducts or square welded air channels. Dampers arranged for closing of all air channels.
Design problems reserved space consumed by other systems. Collision with girders, holes needed in girder web. Horizontal channels below car deck are often rectangular and flat.

16. Engine Room Ventilation Systems
Main ventilation fans (or located at lower end)
Accommodation ventilation room
Casing can be tightly closed in case of fire
Main duct with major branches to engines and burners
Separate air channel to control room
Air cooling unit
Branch duct to spaces below floor
Suction from purifier room and below floor

17. Exhaust Gas System
Exhaust gas piping has influence on engine performance, noise emission and general fire safety. Flow velocity 35 m/s
Support must permit thermal expansion, disconnect structural noise and prevent loads on turbine casing. Special demands in resiliently mounted engines.
Space problems in engine room (below car deck) and inside the too crowded casing
Heat recovered from main engines, sometimes aux. engines
Catalyst reactor fitted before boiler. Separate noise silencer needed in most ships
Exhaust gas boilers have separate gas side, water side may be common.

18. Pakoputken vienti autokannen alla

19. Exhaust Gas System
Boiler by-pass line is seldom used in Europe for capacity control
Heavy boiler demands strong support structure
Rain or boiler wash water must in no conditions reach engine
Bellows and supports allow thermal expansion.
Overhaul space of exhaust boiler tube bundles
Strong support on pipe corners is vital.

20. Exhaust Gas Piping
Ventilation air exit Aux. engine exhaust pipe Exhaust gas boilers
Steam boiler exhaust pipe
Main engine exhaust pipe

21. Ventilation Systems – MS Seahorse
Free air exhaust through casing
4 Engine room supply fans
Silencing air intake grid and chamber
4 main air inlet channels, some extend to ER floor
Air suction fans and ducts from purifier room

22. Typical exhaust boiler
Exhaust Gas System
Typical exhaust boiler
Water circulates in 30mm steel tubes, rib distance 15mm
Feed water in
Hatch to tube end chamber
Rotatable soot removal steam blower
Hatch to exhaust gas chamber
Steam & feed water mixture out

23. Starting Air and Exhaust Gas Systems – MS Seahorse
Main engine exhaust pipe
Main air receivers
Aux engine exhaust pipe
Main air compressors
Working air receiver

24. Starting Air and Exhaust Gas Systems – MS Seahorse
Main engine exhaust pipe & composite steam boiler
Main air compressors
Main air receivers
Working air receiver and compressor
Main deck 19500
Third deck 12200
Double bottom 2700
Base line