Marine Diesel Engine Marine Diesel Engine SystemSystem

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• Course Learning Objective: Course Learning Objective: Describe the, Describe the, basic requirement and design features basic requirement and design features of marine engine piping systemof marine engine piping system

Specific Learning Objectives:Specific Learning Objectives:

State the essential parameters and operation of fuel oil,State the essential parameters and operation of fuel oil,lubricating oil system, piston cooling system, jacket lubricating oil system, piston cooling system, jacket cooling system, sea water cooling system and theircooling system, sea water cooling system and theirrespective inlet and outlet operrespective inlet and outlet operating conditionating condition

Fuel Oil SystemFuel Oil System

The fuel oil system is the heart of marine The fuel oil system is the heart of marine diesel enginediesel engine

System design depends on type of fuel that System design depends on type of fuel that require balance of the following:require balance of the following:

o Reduced space and weightReduced space and weighto Increased reliabilityIncreased reliabilityo Lower wear partLower wear parto Good cold starting capabilityGood cold starting capabilityo Increased safety in fuel handling and safetyIncreased safety in fuel handling and safety

Fuel characteristics and engine Fuel characteristics and engine performanceperformance

Cetane number-> measure of ignition quality of Cetane number-> measure of ignition quality of fuel -> cold starting warm-up, combustion fuel -> cold starting warm-up, combustion roughness, deposited under idle and light load roughness, deposited under idle and light load operation and exhaust smoke densityoperation and exhaust smoke density

Heating value-> express in HP- Hr -> depends on Heating value-> express in HP- Hr -> depends on properties such volatility, viscosity, gravity, properties such volatility, viscosity, gravity, ignition qualityignition quality

Viscosity -> min (power loss from injector pump Viscosity -> min (power loss from injector pump and leakage), max( engine design, size, and and leakage), max( engine design, size, and characteristics of injection)characteristics of injection)

Sulphur ->wears and deposit problem-> maintain Sulphur ->wears and deposit problem-> maintain jacket water at 140 F to minimize effectjacket water at 140 F to minimize effect

Flash point->safety and precaution handling and Flash point->safety and precaution handling and storage-> legal implication-> mostly at 140Fstorage-> legal implication-> mostly at 140F

Pour point -> lowest temperature requirement- > Pour point -> lowest temperature requirement- > depend on certain numberdepend on certain number

Fuel Selection ConsiderationFuel Selection Consideration

Specify by owner or ship designerSpecify by owner or ship designer Fuel price and availabilityFuel price and availability Maintenance considerationMaintenance consideration Engine size and designEngine size and design Speed and load rangeSpeed and load range Frequency of speed and load rangeFrequency of speed and load range Ambient temperatureAmbient temperature

Fuel typesFuel types- Heavy fuel -> mostly continuous operationHeavy fuel -> mostly continuous operation- Diesel oil -> maneuveringDiesel oil -> maneuvering

ASTM 1D-volatile distillate for high speed engine- flashpoint of ASTM 1D-volatile distillate for high speed engine- flashpoint of 140F140F

ASTM 2D-Distilate fuel oil of lower volatile – flash point of 140FASTM 2D-Distilate fuel oil of lower volatile – flash point of 140FASTM 4D-FUEL OIL FOR LOW AND MEDIUM SPEED ENGINEASTM 4D-FUEL OIL FOR LOW AND MEDIUM SPEED ENGINEMIL-F-16884-Marine diesel fuel for military application- similar MIL-F-16884-Marine diesel fuel for military application- similar

to 2Dto 2DMIL-T-5524-Marine turbine fuel for military application- similar MIL-T-5524-Marine turbine fuel for military application- similar

to 1Dto 1DJP 5 – expensive, use one grade of distillate in tankers.JP 5 – expensive, use one grade of distillate in tankers.MIL-F- cannot be use for marine applicationMIL-F- cannot be use for marine application

Fuel oil System Fuel oil System

Fuel Oil SystemFuel Oil System Parts-> Fuel supply & Fuel injectionParts-> Fuel supply & Fuel injection Fuel journey starts from double bottom Fuel journey starts from double bottom

tank (storage) -> settling tank (+heating)-tank (storage) -> settling tank (+heating)-> centrifuge (cleaning) ->daily tank (ready > centrifuge (cleaning) ->daily tank (ready for engine use).for engine use).

Daily service tank -> 3 way valves -> Daily service tank -> 3 way valves -> mixing tankmixing tank

Booster pump -> heaters (heat engine Booster pump -> heaters (heat engine before starting) ->viscosity regulator before starting) ->viscosity regulator (control fuel oil temperature) ->engine (control fuel oil temperature) ->engine driven fuel pumps ->fuel injector (@high driven fuel pumps ->fuel injector (@high pressure)pressure)

System AuxiliariesSystem Auxiliaries

Flow meter- to indicate fuel consumptionFlow meter- to indicate fuel consumption Pressure regulating valve- ensure constant Pressure regulating valve- ensure constant

pressure supply to fuel pumppressure supply to fuel pump Mixing tank – for recalculation, buffer or Mixing tank – for recalculation, buffer or

reservoir tank when daily oil tank is emptyreservoir tank when daily oil tank is empty preheating arrangement (heat engine preheating arrangement (heat engine before starting) before starting)

Low level alarmsLow level alarms Remotely operated outlet valve – which Remotely operated outlet valve – which

can be closed in the event of fire.can be closed in the event of fire.

Fuel InjectorFuel Injector To provide right amount of fuel at the right To provide right amount of fuel at the right

time, and suitable condition for the time, and suitable condition for the combustion processcombustion process

This necessitate measure/timing This necessitate measure/timing arrangement for fuel delivery and arrangement for fuel delivery and atomization.atomization.

Injection is achieved by location o the cam on Injection is achieved by location o the cam on the cam shaftthe cam shaft

Camshaft rotate at speed of engine for 4 Camshaft rotate at speed of engine for 4 stroke and half stroke for 2 stroke enginestroke and half stroke for 2 stroke engine

Two types of system- both operate on Two types of system- both operate on mechanical and hydraulic operationmechanical and hydraulic operation

- Jerk pump and common rail-> separate Jerk pump and common rail-> separate injector for each cylinderinjector for each cylinder

-Common rail has high pressure multiple -Common rail has high pressure multiple plunger fuel pumpplunger fuel pump

Imagine Imagine the ideal the ideal devicedevice

Lubricating SystemLubricating System

USE OF LUBRICATION OILUSE OF LUBRICATION OIL

To reduce friction and wear – keep metal surface To reduce friction and wear – keep metal surface clean by carrying away possible depositsclean by carrying away possible deposits

To providing a seal to keep out dirtTo providing a seal to keep out dirt Carrying heat generated away in bearing and gear Carrying heat generated away in bearing and gear

etc – to prevent overheating, seizure and etc – to prevent overheating, seizure and breakdownbreakdown

By added a proper amount of additives ( chemical By added a proper amount of additives ( chemical compound) on it – improved protection to compound) on it – improved protection to machineries and life of oil itself machineries and life of oil itself

** It is important for marine technology to be ** It is important for marine technology to be familiar with LO oil in making design regarding familiar with LO oil in making design regarding engine selection engine selection

LOLO

LO are classified by:LO are classified by:

-Viscosity -> temperature dependent-Viscosity -> temperature dependent

-Severity of operating conditions - > sulfur, -Severity of operating conditions - > sulfur, carbon, fluctuating load, frequent starts carbon, fluctuating load, frequent starts and stopand stop

Most common LO is given by SAE numbersMost common LO is given by SAE numbers

-SAE 30 or 40 – medium and high speed -SAE 30 or 40 – medium and high speed enginesengines

SAE 5W OR 10W – small boat, cold weatherSAE 5W OR 10W – small boat, cold weather

LO AdditiveLO Additive Anti-oxidant – reduces oxidation rate – sludge when Anti-oxidant – reduces oxidation rate – sludge when

hothot Corrosion inhibitor – alkaline additive – neutralise Corrosion inhibitor – alkaline additive – neutralise

acidityacidity Detergents – Keep metal surface cleanDetergents – Keep metal surface clean Dispersants – prevent small particles forming large oneDispersants – prevent small particles forming large one Pour point depressant – keep low temperature or Pour point depressant – keep low temperature or

crystals layercrystals layer Anti-foaming – prevent foaming – jamAnti-foaming – prevent foaming – jam Viscosity index improver – maintain viscosity as near Viscosity index improver – maintain viscosity as near

constant in variable temperatureconstant in variable temperature Oiliness and extreme pressure – reduce friction and Oiliness and extreme pressure – reduce friction and

wearwear Emulsifying and demulsifying agentEmulsifying and demulsifying agent

CYLINDER LUBRICATING

OIL SERVICE TANK

CYLINDER

LUBRICATION

BOXES

SEA WATER OUTLET

CROSSHEAD & P ISTON LUB

DISTRIBUTION OIL

MANIFOLD COOLER

SEA WATER INLET

FINE FILTERS

MAIN BEARING & CRANKP IN

DISTRIBUTION MANIFOLD

LUB OIL PUMPS

STRAINERS MAGNETIC FILTERS

STEAM

HEATING

LUB OIL PURIFIER

HEATER

COLLECTING TANK

DRY SUMP TANK

LUBRICATING OIL

CONTROL VALVE

TEMPERATURE

LUBRICATION OIL SYSTEM

MAIN DIESEL ENGINE

Lubrication Oil SystemLubrication Oil System

System start journey from bottom of System start journey from bottom of crankcase sump or drain tank -> pump -> crankcase sump or drain tank -> pump -> strainer -> cooler -> engine and strainer -> cooler -> engine and distributed to engine partsdistributed to engine parts

Branch pipe inside engine feed:Branch pipe inside engine feed:-main bearing – drilled passage in crankshaft -main bearing – drilled passage in crankshaft

to the bottom end bearing – then up a to the bottom end bearing – then up a drilled passage in the collecting rod to the drilled passage in the collecting rod to the gudgeon pin or cross head bearinggudgeon pin or cross head bearing

After use , oil flow back to the sump or After use , oil flow back to the sump or drain tank for reusedrain tank for reuse

System auxiliary System auxiliary Alarm- ensure that adequate pressure is maintained by the Alarm- ensure that adequate pressure is maintained by the

pumppump Pump and pipe filters are duplicated for standby purposePump and pipe filters are duplicated for standby purpose gauge level- local reading outgauge level- local reading out Centrifuge – cleaningCentrifuge – cleaning Oil cooler- by low pressure sea water supply at lower Oil cooler- by low pressure sea water supply at lower

pressure - at leakage there is loss of oil and no mixing of oil pressure - at leakage there is loss of oil and no mixing of oil and waterand water

Oil cooled piston must be supply at high pressure (booster Oil cooled piston must be supply at high pressure (booster pump) and right quantity( to prevent carbon deposit)- i.e pump) and right quantity( to prevent carbon deposit)- i.e sulzersulzer

Cylinder lubrication- provided for large slow speed diesel Cylinder lubrication- provided for large slow speed diesel engine for cylinder liner and pistonengine for cylinder liner and piston

- unrecoverable- unrecoverable-provide gas seal and contain additive that clean the cylinder-provide gas seal and contain additive that clean the cylinder

LO TransportationLO Transportation

LO transport starts from :LO transport starts from : Sump (storage) -> strainer -> pumps -Sump (storage) -> strainer -> pumps -

>filters -> cooler -> engine distribution)>filters -> cooler -> engine distribution) Distribution – main bearing -> drilled Distribution – main bearing -> drilled

passage in crankshaft -> bottom end passage in crankshaft -> bottom end bearing->up drilling passage to the bearing->up drilling passage to the connecting rod->gudgeon pin or cross connecting rod->gudgeon pin or cross head bearinghead bearing

After use the LO drain back to the tank for After use the LO drain back to the tank for reusereuse

Fittings:Fittings: Alarm (adequate supply of LOAlarm (adequate supply of LO Pumps and filters (duplicate arrangement for Pumps and filters (duplicate arrangement for

standby purpose)standby purpose) Level gauge (local read out of the drain tank level)Level gauge (local read out of the drain tank level) Centrifuge (cleaning of oil)Centrifuge (cleaning of oil) Oil cooler (circulated sea water @low pressure)Oil cooler (circulated sea water @low pressure) Oil cooled system supplied by booster pump Oil cooled system supplied by booster pump

@high pressure@high pressure Cylinder lubrication – for large slow speed diesel Cylinder lubrication – for large slow speed diesel

engine -> special types of oil that independently engine -> special types of oil that independently inject oil between each cylinder and piston -> it inject oil between each cylinder and piston -> it also help to form gas seal and additive for liner also help to form gas seal and additive for liner cleaning.cleaning.

Cooling SystemCooling System

Cooling SystemCooling System A diesel engine works on the principle of internal A diesel engine works on the principle of internal

combustion of fuel oil. The pistons of the engine combustion of fuel oil. The pistons of the engine are driven by the controlled explosion of the fuel-are driven by the controlled explosion of the fuel-air mixture, and corresponding rapid increase in air mixture, and corresponding rapid increase in pressure inside the cylinders. pressure inside the cylinders.

A marine diesel engine is designed for non-stop A marine diesel engine is designed for non-stop operation. operation.

From the time the ship departs from a port until it From the time the ship departs from a port until it reaches another port, the main engine has to run. reaches another port, the main engine has to run. This could last several months. This could last several months.

The heat from the combustion of fuel have to be The heat from the combustion of fuel have to be taken away continuously otherwise the metal taken away continuously otherwise the metal components will become damaged. components will become damaged.

The material properties of the engine parts can The material properties of the engine parts can change when it reaches high temperatures -change when it reaches high temperatures ->Thermal stress can occur leading to cracks, >Thermal stress can occur leading to cracks, deformation and weaknesses in the material. deformation and weaknesses in the material.

Cooling SystemCooling System

Continuous cooling of the engine is necessary. The Continuous cooling of the engine is necessary. The temperatures have to be maintained at an optimum temperatures have to be maintained at an optimum level. level.

They must not be too hot or too cold. The normal They must not be too hot or too cold. The normal engine jacket outlet temperature is usually engine jacket outlet temperature is usually maintained at about 68 to 70 degree Centigrade, maintained at about 68 to 70 degree Centigrade, the piston cooling outlet temperature about 55 the piston cooling outlet temperature about 55 degree Centigrade. degree Centigrade.

The lubrication oil temperature is maintained to The lubrication oil temperature is maintained to about 40 degree Centigrade. The temperatures are about 40 degree Centigrade. The temperatures are maintained as steady as possible. maintained as steady as possible.

The control systems are designed so that The control systems are designed so that fluctuations in temperatures can be measured and fluctuations in temperatures can be measured and controlled easily.controlled easily.

Huge fluctuations in temperatures not only cause Huge fluctuations in temperatures not only cause undue thermal stress, but also can cause the undue thermal stress, but also can cause the rubber seals to leak. rubber seals to leak.

Main Diesel Engine SystemMain Diesel Engine System

The main diesel engine cooling The main diesel engine cooling systems consists of the following: systems consists of the following:

Jacket Cooling Water SystemJacket Cooling Water System Piston Cooling Water SystemPiston Cooling Water System Lubrication Oil Cooling SystemLubrication Oil Cooling System Fuel Valve Cooling Water SystemFuel Valve Cooling Water System

Jacket Cooling Water SystemJacket Cooling Water System Water is pump via one of two centrifugal pumps. One is Water is pump via one of two centrifugal pumps. One is

normally in use with the other stand-by. The water passes normally in use with the other stand-by. The water passes through to the distributing manifold on the engine side. through to the distributing manifold on the engine side.

Jacket Water HeaterJacket Water Heater In the line is a steam jacket water In the line is a steam jacket water heater. When the engine is shut down steam heating heater. When the engine is shut down steam heating maintains the engine in a state of readiness reducing the time maintains the engine in a state of readiness reducing the time needed for starting. Attempting to start the engine without needed for starting. Attempting to start the engine without heating can lead to poor combustion, poor lubrication and heating can lead to poor combustion, poor lubrication and thermal shocking.thermal shocking.

The water enters and leaves the engine via a series of The water enters and leaves the engine via a series of cylinder isolating valves. In this way each cylinder may be cylinder isolating valves. In this way each cylinder may be individually drained to prevent excessive water and chemical individually drained to prevent excessive water and chemical loss. loss.

In addition dual level drains may be fitted which allow either In addition dual level drains may be fitted which allow either full draining or draining of the head only. A portion of the full draining or draining of the head only. A portion of the water is diverted for cooling of the turbocharger. water is diverted for cooling of the turbocharger.

Jacket Water Cooling Jacket Water Cooling SystemSystem

Jacket Water Cooling SystemJacket Water Cooling System DeaeratorDeaerator Was an essential part of engines incorporating water Was an essential part of engines incorporating water

cooled pistons-> In the event of gas leakage via the head or cooled pistons-> In the event of gas leakage via the head or cracked liner rapid loss of jacket water pressure can occur. The cracked liner rapid loss of jacket water pressure can occur. The deaerator is a method to try to slow this process sufficiently to deaerator is a method to try to slow this process sufficiently to allow the vessel to be placed in a safe position for maintenance.allow the vessel to be placed in a safe position for maintenance.

Jacket Water CoolerJacket Water Cooler The hot water leaving the engine passes to The hot water leaving the engine passes to a temperature control valve were a portion is diverted to a cooler. a temperature control valve were a portion is diverted to a cooler. Temperature is controlled using both a feedback signal Temperature is controlled using both a feedback signal (temperature measured after the cooler) and a feed forward signal (temperature measured after the cooler) and a feed forward signal (temperature measured at outlet from the engine). In this way the (temperature measured at outlet from the engine). In this way the system reacts more quickly to engine load variations.system reacts more quickly to engine load variations.

Evaporator IncreasesEvaporator Increases plant efficiency by utilizing heat in jacket plant efficiency by utilizing heat in jacket

water to produce fresh water. water to produce fresh water.

Expansion or header tankerExpansion or header tanker Maintains a constant head on the Maintains a constant head on the circulation pumps reducing cavitations at elevated temperatures. circulation pumps reducing cavitations at elevated temperatures. Allows the volume of water in the system to vary without need for Allows the volume of water in the system to vary without need for dumping. Acts as a reserve in the event of leakage. dumping. Acts as a reserve in the event of leakage.

EXPANSION / HEADER TANK

TURBOCHARGER S/W OUT

TO & FROM

DIESEL GENERATOR

J ACKET

WATER

COOLER

J KT. WATER COOLING P /P S

CYLINDER BLOCK S/W IN

& CYLINDER HEAD

DISTRIBUTION MANIFOLD

S/W OUT

P ISTONS

DISTRIBUTION MANIFOLD P ITON

WATER

P ISTON WATER COOLING P /P S COOLER

COLLECTION MANIFOLD S/W IN

FROM P ISTON

FRESH WATER SYSTEM

MAIN DIESEL ENGINE

P ISTON DRAIN TANK

HEATER

Fresh Water Cooling SystemFresh Water Cooling System

Piston Cooling Water Piston Cooling Water SystemSystem

The piston crown is subjected to intense heat The piston crown is subjected to intense heat from the combustion of fuel oil. Because the from the combustion of fuel oil. Because the piston moves up and down in a reciprocating piston moves up and down in a reciprocating manner, some means of supplying the water to manner, some means of supplying the water to the internal compartments of the piston must be the internal compartments of the piston must be available. available.

Some engines use telescopic and stand pipe Some engines use telescopic and stand pipe arrangements to supply water for cooling the arrangements to supply water for cooling the piston crowns. Others may use the lubrication oil piston crowns. Others may use the lubrication oil as a coolant although the cooling effect is not as as a coolant although the cooling effect is not as good. good.

The water, after passing through the piston The water, after passing through the piston compartments is allowed to flow out to a compartments is allowed to flow out to a collection tank outside the engine. collection tank outside the engine.

If the engine uses oil for cooling, then the latter If the engine uses oil for cooling, then the latter is allowed to drop into the engine oil sump tank. is allowed to drop into the engine oil sump tank.

Lubrication Oil Cooling Lubrication Oil Cooling SystemSystem

The lubrication oil, after lubricating the moving parts of the The lubrication oil, after lubricating the moving parts of the bearings will finally drop down to the sump tank of the bearings will finally drop down to the sump tank of the engine. engine.

From the sump tank, the oil is pumped to the oil cooler for From the sump tank, the oil is pumped to the oil cooler for cooling. The controller will ensure that the oil becomes cooling. The controller will ensure that the oil becomes cooled to the required temperatures. cooled to the required temperatures.

Depending on the engine, there may also be a turbocharger Depending on the engine, there may also be a turbocharger cooling oil system that uses its own cooling system. (The oil cooling oil system that uses its own cooling system. (The oil is different from the main engine, so it must not mix) is different from the main engine, so it must not mix)

There will also be a cylinder lubrication system that injects There will also be a cylinder lubrication system that injects small quantities of oil into the cylinder liners. This is for small quantities of oil into the cylinder liners. This is for lubricating the rubbing surfaces between the piston rings lubricating the rubbing surfaces between the piston rings and the cylinder liner. The oil is not circulated, so there is no and the cylinder liner. The oil is not circulated, so there is no necessity for cooling. necessity for cooling.

Fuel Valve Cooling Water Fuel Valve Cooling Water SystemSystem

Although this system is small, it is nevertheless important for the Although this system is small, it is nevertheless important for the engine. The fuel valve, or injector is the component from where engine. The fuel valve, or injector is the component from where fuel is injected through nozzles. This component of the engine is fuel is injected through nozzles. This component of the engine is subjected to intense heat of the combustion and needs to be subjected to intense heat of the combustion and needs to be cooled. Passages are drilled into the nozzles to enable water to be cooled. Passages are drilled into the nozzles to enable water to be circulated within the nozzle. The water is maintained at 92 degree circulated within the nozzle. The water is maintained at 92 degree Centigrade so as not to flash into steam. Centigrade so as not to flash into steam.

Because of the close loop, this cooling system also has an Because of the close loop, this cooling system also has an expansion tank. expansion tank.

There are other cooling systems other than those for the main There are other cooling systems other than those for the main engine. There will be another set of Jacket Cooling Water System engine. There will be another set of Jacket Cooling Water System for the Electrical Generator Sets. Many of the smaller engines for the Electrical Generator Sets. Many of the smaller engines have built in cooling systems for lubrication oil, and others. Other have built in cooling systems for lubrication oil, and others. Other auxiliary systems like air conditioning, refrigeration, steering gear, auxiliary systems like air conditioning, refrigeration, steering gear, etc. use their own cooling systems. etc. use their own cooling systems.

Usually, the cooling medium is seawater. The above systems have Usually, the cooling medium is seawater. The above systems have very close control limits. Automatic control systems are installed very close control limits. Automatic control systems are installed so that the temperatures can be maintained in a close range. so that the temperatures can be maintained in a close range. Some cooling requirements are not so stringent. These can be Some cooling requirements are not so stringent. These can be controlled manually. A very good example is the air intake cooler. controlled manually. A very good example is the air intake cooler.

For good temperature control, the seawater can also be circulated For good temperature control, the seawater can also be circulated within the engine room piping to maintain the heat. This is useful within the engine room piping to maintain the heat. This is useful during wintertime in freezing conditions.during wintertime in freezing conditions.

TURBOCHARGER

J ACKET

FRESH

WATER

COOLER

CHARGE

AIR COOLER

PISTON LUB OIL

WATER COOLER

COOLER

SEA WATER

COOLING

P UMP S

FILTER FILTER SEA CHEST

SEA CHEST

SEA WATER COOLING SYSTEM

MAIN DIESEL ENGINE

Sea Water Cooling SystemSea Water Cooling System

Scale and deposit Scale and deposit formationformation

In areas of deposit formation, dissolved In areas of deposit formation, dissolved solids, specifically Calcium and magnesium solids, specifically Calcium and magnesium hardness constituents can precipitate from hardness constituents can precipitate from cooling water as the temperature increases. cooling water as the temperature increases.

Deposits accumulate on the heat transfer Deposits accumulate on the heat transfer surfaces as sulphates and carbonates, the surfaces as sulphates and carbonates, the magnitude of which is dependent on the magnitude of which is dependent on the water hardness, the dissolved solid content, water hardness, the dissolved solid content, local temperatures and local flow local temperatures and local flow characteristics. characteristics. Temperature solubility Temperature solubility curves for CaSO4curves for CaSO4

Scale and deposit Scale and deposit formationformation

Scales can reduce heat transfer rates and lead to loss of mechanical strength ofScales can reduce heat transfer rates and lead to loss of mechanical strength of component parts, this can be exacerbated by the presence of oils and metal oxides.component parts, this can be exacerbated by the presence of oils and metal oxides.

Scale and Deposit Scale and Deposit FormationFormation

Calcium Carbonate - Calcium Carbonate - Appears as a pale cream, yellow deposit Appears as a pale cream, yellow deposit formed by the thermal decomposition of calcium bi-carbonate formed by the thermal decomposition of calcium bi-carbonate

Ca(HCO3)2 + Heat becomes CaCO3 + H2O + CO2Ca(HCO3)2 + Heat becomes CaCO3 + H2O + CO2 Magnesium Silicate - Magnesium Silicate - A rough textured off white deposit found A rough textured off white deposit found

where sufficient amounts of Magnesium are present in conjunction where sufficient amounts of Magnesium are present in conjunction with adequate amounts of silicate ions with a deficiency of OH with adequate amounts of silicate ions with a deficiency of OH alkalinity alkalinity

Mg2+ + OH- becomes MgOH+ Mg2+ + OH- becomes MgOH+ H2SiO3 becomes H+ + HSiO3- H2SiO3 becomes H+ + HSiO3- MgOH+ + HSiO3- becomes MgSiO3 + H2SO4 MgOH+ + HSiO3- becomes MgSiO3 + H2SO4

Silicate deposit is a particular problem for systems which utilize Silicate deposit is a particular problem for systems which utilize silicate additives for corrosion protection. This is typical of silicate additives for corrosion protection. This is typical of systems with aluminum metal in the cooling system -> The silicate systems with aluminum metal in the cooling system -> The silicate forms a protective barrier on the metal surface. A high pH (9.5 - forms a protective barrier on the metal surface. A high pH (9.5 - 10.5) is required to keep the silicate in solution. In the event of 10.5) is required to keep the silicate in solution. In the event of sea water contamination or some other mechanism that reduces sea water contamination or some other mechanism that reduces the pH silicate is rapidly precipitated and gross fouling can occur. the pH silicate is rapidly precipitated and gross fouling can occur.

Copper - Copper - The presence of copper within a cooling system is very The presence of copper within a cooling system is very serious as it can lead to aggressive corrosion through galvanic serious as it can lead to aggressive corrosion through galvanic action. Specific corrosion inhibitors are contained with cooling action. Specific corrosion inhibitors are contained with cooling water system corrosion inhibitors. water system corrosion inhibitors.

Air Starting SystemAir Starting System

Air Starting SystemAir Starting System Compressed air from air compressor is stored in air bottle Compressed air from air compressor is stored in air bottle

before supply to the cylinder at appropriate sequence before supply to the cylinder at appropriate sequence The compressed air is supplied to air receiverThe compressed air is supplied to air receiver The compressed air is supplied through large bore pipe to The compressed air is supplied through large bore pipe to

a remotely automatic operated non return valve -> then to a remotely automatic operated non return valve -> then to cylinder air starting valve cylinder air starting valve

The cylinder air starting valve which is operated by engine The cylinder air starting valve which is operated by engine air starting lever and camshaft admit air into the cylinderair starting lever and camshaft admit air into the cylinder

The pilot air system control the opening of the cylinder The pilot air system control the opening of the cylinder valve and remote operating valvevalve and remote operating valve

Pilot air is also supplied to air distributorPilot air is also supplied to air distributor Up to 12 starts are possibleUp to 12 starts are possible The cylinder air starting valve is held closed by spring when The cylinder air starting valve is held closed by spring when

not in usenot in use Starting air system has interlock to present starting if Starting air system has interlock to present starting if

everything is not in order.everything is not in order.

STARTING AIR VALVES

P ILOT

VALVE

AIR BOTTLE

OR

RESERVOIR

AIR DISTRIBUTOR

MAIN AIR

COMP RESSORS

STARTING AIR SYSTEM

MAIN DIESEL ENGINE

No 1 No 2

No 2No 1

Air Starting SystemAir Starting System

Fittings Fittings

In order to reduce effect of explosion the In order to reduce effect of explosion the following are fitted to the air starting following are fitted to the air starting system:system:

-Flame traps -Flame traps

-Relief valve-Relief valve

-Non return automatic valves-Non return automatic valves High temperature alarm against loss of High temperature alarm against loss of

cooling water in air compressorcooling water in air compressor Maintenance and draining of pipeline again Maintenance and draining of pipeline again

LO leakage LO leakage

Control and safety devicesControl and safety devices GovernorGovernor Cylinder relieve valve- operate at excess of 10 to 20 %Cylinder relieve valve- operate at excess of 10 to 20 % Crankcase oil mist detector – Photocell detectorCrankcase oil mist detector – Photocell detector Explosion relieve valveExplosion relieve valve Alarm and automatic shut down -> usually for low lub. Oil Alarm and automatic shut down -> usually for low lub. Oil

pressure, high jacket water temperature, high rpm (excess pressure, high jacket water temperature, high rpm (excess of 115 for ABS) of 115 for ABS)

Coupling , clutches and gearboxCoupling , clutches and gearbox Crank case explosion - Build strong crank case or load the Crank case explosion - Build strong crank case or load the

cover with spring that permit excess air out of the cover with spring that permit excess air out of the crankcasecrankcase

Other systems:Other systems: Waste heat utilization systemWaste heat utilization system Intake and exhaust gas systemIntake and exhaust gas system Installation itemsInstallation items

InstrumentsInstruments1. Pressure gages:1. Pressure gages: Freshwater pump dischageFreshwater pump dischage Seawater pump dischargeSeawater pump discharge Lubricating oil pump dischargeLubricating oil pump discharge Lubricating oil pressure at Lubricating oil pressure at

engine inletengine inlet Piston cooling oil pump Piston cooling oil pump

discharge(if used)discharge(if used) Fuel oil pump dischargeFuel oil pump discharge Fuel oil pressure at injection Fuel oil pressure at injection

pump inletpump inlet Scavenging or supercharging Scavenging or supercharging

pressurepressure Starting pressure at engine Starting pressure at engine

lubricating oil at turbocharger lubricating oil at turbocharger or bloweror blower

Crankcase pressure or Crankcase pressure or vacuumvacuum

2. Thermometers:2. Thermometers:Lubricating oil from engineLubricating oil from engineFresh water from engneFresh water from engneFuel temperature to the engine Fuel temperature to the engine

wen heated heavy fuel oil are wen heated heavy fuel oil are usedused

3. Tachometer3. Tachometer

4. Exhaust gas pyrometer 4. Exhaust gas pyrometer indicatorindicator

Other systemsOther systems

SummarySummary Diesel engine systems and other Diesel engine systems and other

system i.e fuel Valve cooling, system i.e fuel Valve cooling, Cylinder LO etc.,Cylinder LO etc.,

QUESTIONS QUESTIONS