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Basic Training Program
Organized by
Mr. Md. Azharul Islam
DGM ( O&M )
Jamuna Power Ltd.
Mr. Debasish Das
DGM ( Electrical )
Jamuna Power Ltd.
Submitted by
Md. Mizanur Rahman
Manager ( Shift In charge)
Jamuna Power Ltd.
Januna Indudtrial Park
Bejura, Madhabpur, Habigonj.
6. ENGINE SYSTEM’S
Lube Oil System
Cooling Water System
Fuel System
Air Starting System
Exhaust Gas System
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Charge Air System
7. Cooling Water System
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The Engine is cooled by treated fresh water in a close-
circuit cooling system. The cooling water circuit is
divided into a High-Temp ( HT ) and
Low-Temp ( LT ) Circuit.
Both Cooling water circuits are provided with either
engine mounted or externally mounted water pumps and
three way valves.
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Why Engine Cooling System ?
All internal combustion engines produce
heat as a byproduct of combustion and
friction.
Overheating, overcooling can have
negative effects on the engine. Overcooling
can reduce engine performance and shorten
the engine’s service life.
Cooling systems are used to manage
engine heat.
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Basic Components of Cooling System
Most IC engines use a closed loop jacket
type cooling system.
The basic components are the coolant,
water pump, engine oil cooler, coolant
temperature regulators, radiator fan and the
radiator, Jacket Water Heater etc.
Coolant flows through the engine absorbing
heat from the cylinder liners, cylinder heads,
and other engine components.
Coolant expands as it is heated. Expansion
tanks are used on some applications to
contain the increased volume.
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Types of Cooling Systems
There are two basic types of cooling systems
1.Open cooling system - Open systems include
cooling towers (without heat exchanger), spray
ponds and bodies of water. Open systems are
not recommended.
2. Closed cooling system - Closed systems
include cooling towers (with heat exchanger),
radiators, heat exchangers . Radiator cooling is
the most common type of closed cooling
system, providing a self-contained system that
is both simple and practical for most
installations.
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Heat Transfer Components
There are three common components used to transfer heat from
the engine such as-
1. Jacket Water:
The water jacket in an internal combustion engine is a series of
cavities and passages that carry coolant throughout the engine.
Heat is transferred from the engine to the coolant and carried away
to a radiator or similar device where the heat can be dissipated.
Water jacket coolant is often circulated through aftercoolers and oil
coolers to collect heat and carry it away from the engine.
2. Oil Cooler:
Oil cooler is used to dissipate heat from the oil to maintain optimum
temperatures for proper lubrication.
Coolant is circulated through the oil cooler to absorb the heat from
the lubricating oil.
3. Aftercoole:
Intake air temperature increases when compressed by the
turbocharger. On a diesel engine, an aftercooler is used to reduce
the air temperature for better combustion.
14. Cooling Water System
Table of contents
LT Water Circuit
LT cooling water system on engine
HT Water Circuit
HT cooling water system on engine
Cooling Water System on WOIS
Cooling water circulation in cylinder head
Multiduct
Cylinder Liner
Built-on LT and HT water pumps
Three way Valve
Radiator
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LT Water Cooling
HT Water Cooling
Charge Air Cooler 2nd Stage
Lube Oil Cooler
Charge Air Cooler 1st Stage
Engine Block
Cylinder head
Liner
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LT Water Circuit
The low-temperature (LT) circuit cools the charge air
and the lubricating oil. The circuit comprises :
● Cooling water LT pump
● Charge air cooler
● Lubricating oil cooler
The cooling water flows first through the charge air
cooler, then to the lubricating oil cooler, and last
through the LT Three way valve.
Depending on the installation, the LT water can be
connected to the high-temperature (HT) section of the
charge air cooler after the lubrication oil cooler.
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HT Water Circuit
The high-temperature (HT) circuit cools the cylinder liners,
cylinder heads, and charge air. The circuit comprises of:
● Cooling water HT pump
● Charge air cooler's HT section (if a two-stage cooler is used)
From the HT cooling water pump, the water flows to a
distributing duct which is cast in the engine block. From the
distributing duct, the water flows to the cylinder water jacket,
and further to the cylinder head.
In the cylinder head, around the valves to the exhaust valve
seats, and up along the pre chamber sleeve.
From the cylinder head, the water flows out through a
connection pipe through the multiduct to the collecting pipe, and
then through the first stage of the charge air cooler, or to a
preheating unit in stand-by mode, unless only low-temperature
(LT) water is used for charge air cooling.
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Three Way Valve
The temp of the cooling water is controlled by
automatic Three-Way valves. The Three-Way
valves regulate the flow of water to the engine
and to the radiator, to keep the cooling water
temp at correct level as the engine load on the
ambient conditions changes.
The valves are operated pneumatically
according to signals from the control system. In
case the air pressure or the control signal is
lost, the valve returns to its fail-safe position,
directing all water for cooling.
29. MCM checks and analyze data . If exceeded the limit
, A signal send to the ESM for engine shutdown.
Critical sensors are connected to the ESM and their
measurements can activate automatic shutdowns.
The following sensors/signals are:
• PTZ201: Low lubricating oil pressure, engine
inlet
•TEZ402 and TEZ403:HT water
temperature (A&B bank: which
is higher)
• ST173/ST174: Engine speed (over-speed trip)
• Emergency stop: button Pressing shuts down the
engine instantly
Fig. Engine safety module (ESM)
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Radiator Works
The radiator removes heat from the HT cooling
water. The main components of the air-cooled
radiator are the heat transfer coil and the
cooling fans.
The heat transfer coil is made of copper tubes
with aluminium fins. The cooling fans are driven
by electric motors, and the speed of the fans is
controlled by a frequency converter according to
the cooling need. Each fan is equipped with a
safety-switch. .
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VFD ( Variable Frequency Drive )
A variable frequency drive controls the speed of an AC motor
by varying the frequency supplied to the motor.
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Cooling Water Quantity& Quality
LT Water = 310 Ltrs
HT Water = 940 Ltrs
No. of Radiator = 02
Expansion Vessel = 600 Ltrs
Total Cooling Water
( Engine+Pipe+Radiator) = 6200 to7500 Ltrs
( Approx.)
Radiator = 2*780 Ltrs
No. of Radiator fan =14
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Property Limit for
Chemical
Use
Limit for
WWCU use
Unit Test Method
reference
pH 6.5-8.5 6.5-8.5 - ASTN D
1287
Hardness
(Ca+Mg)
Max 10 Max 10 ºdH ASTM D
1126
Chlorides (Cl) Max 80 Max 40 mg/l ASTM D 512
Sulphates
(SO4)
Max 150 Max 100 mg/l ASTM D 516
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Modern Treatment
A modern treatment will be a Nitrite -Borate base, with a complex blend of
organic and inorganic scale and corrosion inhibitors plus surfactants,
alkali adjusters, dispersants and foam suppressers. A high quality water
supply is still strongly recommended. Nitrite-Borate treatment is most
effective with a high quality water base.
For corrosion to occur four conditions must be met
There must be an Anode
There must be a cathode
An electrolyte must be present
An electron pathway should exits
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Validated Cooling Water Additives
Product Designation Doses per 1m of
system capacity
Concentration of
active corrosion
inhibitors
Nalfleet 2000 32-48 ltrs 1000-1500 ppm as
per N02
New Condition
Used Condition ( Approx.)
Product Designation Doses per 100trs of
system capacity
Concentration of
active corrosion
inhibitors
Nalfleet 2000 01 Ltrs 300 ppm as per N02
For many products the recommended minimum and maximum limits
are listed in the table in the engine manual.
The additive we use in our engine is nalfleet 2000
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Problems for cooling water system
Typical problems in cooling water
1.Scaling or Deposit Formation
2.Corrosion and
3.Microbiological Fouling
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Scaling of Jacket Water System
Scale and deposit formation In areas
of deposit formation, dissolved
solids, specifically Calcium and
magnesium hardness constituents
can precipitate from cooling water
as the temperature increases. The
magnitude of which is dependent
on the water hardness, the
dissolved solid content, local
temperatures and local flow
characteristics. Scales can reduce
heat transfer rates and lead to loss
of mechanical strength of
component parts.
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Example of corrosion
Pitting corrosion
Crevice attack
Galvanic corrosion
Pitting corrosion is usually the result of galvanic corrosion.
This occurs when two different metals and water come together
as electrolytes. This creates charges – like in a battery, electrons
flow. The result is a small pit. The electrons flow from the base
metal to the noble metal and produce the pitting.
Crevice corrosion refers to the attack of metal surfaces by a
stagnant solution in crevices, for example around the edges of
nuts and rivet heads. When dust, sand and other corrosive
substances are deposited on surfaces, they create an
environment where water will accumulate and corrode the part.
Galvanic corrosion, also known as bimetallic corrosion, is an
electrochemical process whereby one metal corrodes in
preference to another metal that it is in contact with through an
electrolyte. Galvanic corrosion occurs when two dissimilar
metals are immersed in a conductive solution and are
electrically connected.
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Effects of Corrosion
Leakage is occurred in the close system
Loss of Metal
Engine may damage as well as
unexpected machine shutdown
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Effects of Corrosion
1. LT & HT Pump Impeller
2. Charge Air Cooler
3. Lube Oil Cooler
4. Cylinder Head
5. Valve
6. Liner
7. Radiator
8. Pipe Line
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All anodes should be removed and the system inspected.
No galvanized piping is to be used. High quality water
should be used and chemicals measured and added as
required.
Under certain conditions bacteria found in cooling water
systems can adapt to feed on the nitrite treatment. This can
lead to rapid growth, formation of bio-films, fouling and
blockages. Typical evidence is a loss of nitrite reserve but a
stable or rising conductivity level as the nitrate formed still
contributes to the conductivity, Problems of this sort are rare
due to the elevated temperatures and pH levels. Should it
occur treatment with a suitable biocide is required.
Microbiological Fouling.
