pentti häkkinen er auxiliaries 9.2. wärtsilä new professionals 3.-7.11.2008 machinery auxiliary...

Pentti Häkkinen ER auxiliaries 9.2. Wärtsilä New Professionals 3.-7.11.2008

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


Cooling Systems

Cooling energy distribution at various load

Fuel energy 100%

Radiation Mechanical energy

1 % 47%

Exhaust gas 26 %

Exhaust gas heat recovery can increase the produced mechanical energy 3%

Cooling water loss 26%


LT Cooling System

Bypass line for low load

HT water cooler

Lub oil cooler

Air cooler II stage

Gear cooler Other coolers

Therm. valve Central coolers

Air evacuation, expansion tk

Throttle


Direct driven pumps

Direct driven cooling water pumps

Direct driven lubrication oil pump


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



Intake Filter Temper. Main SW Isolation Double grating basket sensor line valve bottom

3-way valve

Side valve

Central coolers Air pipe

Ice sea chest (which is extending above CWL)

Non-return valve

S.W. pump



Sea water and fresh water cooling pumps

Main sea water cooling line, mixing valve and filter


Sea Water Cooling Systems

Alternatives Box cooler, good operation record in smaller ships

Vent pipe

Inlet grid Outlet grid

Shelter plate

Bolted flange

Cleaning air feed

Keel cooler, used in Mississippi muddy waters, in river boats

Shallow (H= 100 mm) tank against bottom plate. Internal baffle plates promote the heat transfer


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


Starting Air System

General

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


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.


Engine Room Ventilation Systems

Casing can be tightly closed in case of fire

Main ventilation fans (or located at lower end)

Accommodation ventilation room

Separate air channel to control room

Air cooling unit

Branch duct to spaces below floor

Suction from purifier room and below floor

Main duct with major branches to engines and burners


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.


Pakoputken vienti autokannen alla


Exhaust Gas System

Bellows and supports allow thermal expansion.

Overhaul space of exhaust boiler tube bundles

Strong support on pipe corners is vital.

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


Exhaust Gas Piping

Steam boiler exhaust pipe

Ventilation air exit Aux. engine exhaust pipe Exhaust gas boilers

Main engine exhaust pipe


Ventilation Systems – MS Seahorse

30 35 40 45 50 55 60 65 70 75-5 0 5 10 15 20 25

4 Engine room supply fans

Air suction fans and ducts from purifier room

4 main air inlet channels, some extend to ER floor

Free air exhaust through casing

Silencing air intake grid and chamber


Exhaust Gas System

Typical exhaust boiler

Feed water in

Steam & feed water mixture out

Rotatable soot removal steam blower

Hatch to tube end chamber

Water circulates in 30mm steel tubes,

rib distance 15mm

Hatch to exhaust gas chamber


Starting Air and Exhaust Gas Systems – MS Seahorse

30 35 40 45 50 55 60 65 70 75-5 0 5 10 15 20 25

Main air compressors

Main air receivers

Main engine exhaust pipe

Aux engine exhaust pipe

Working air receiver


Starting Air and Exhaust Gas Systems – MS Seahorse

Third deck 12200

Main deck 19500

Double bottom 2700

Base line

Main air compressors

Main air receivers

Main engine exhaust pipe & composite steam boiler

Working air receiver and compressor

pentti häkkinen er auxiliaries 9.2. wärtsilä new professionals 3.-7.11.2008 machinery auxiliary...

Documents

pentti hkkinen er auxiliaries

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cooling water loss

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sea water main line

cooling energy demand

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