Ship's Fresh Water Cooling System | Study Call Ep 003 Chief MAKOi

Summary

This episode of 'Study Call the Chief McCoy' delves into the freshwater cooling system of ships, essential for protecting engines from corrosion and providing clean water for crew needs. It explains the high-temperature line's role in cooling engines by transferring heat to seawater and highlights the system's components, including the expansion tank, jacket cooling water pumps, and jacket water cooler. The video also touches on the use of preheaters and the potential for a low-temperature line for auxiliary machinery, setting the stage for future discussions on central cooling systems and other maritime topics.

Takeaways

• 🚢 The ship's freshwater system is essential for cooling engines and domestic use, as seawater causes corrosion and is unsuitable for consumption or sanitation.
• 🔍 The freshwater system is divided into two subsystems: freshwater cooling and domestic freshwater, with this episode focusing on the former.
• 🛠️ Ships with diesel engines have a different freshwater cooling system configuration compared to those with steam turbines.
• 🔥 The freshwater cooling system absorbs heat from the main and auxiliary engines and transfers it to the seawater system for disposal.
• 💧 The main feature of the freshwater cooling system is the high-temperature (HT) line, which is a closed-loop system.
• 🚰 Freshwater from the expansion tank is circulated by jacket cooling water pumps through the engine cylinders to maintain optimal temperatures.
• 🔄 A temperature-controlled three-way valve redirects water flow to either return to the main engine or pass through the jacket water cooler.
• ♨️ A preheater in the HT line maintains jacket water temperature when the engine operates at slow speeds, like during maneuvering.
• 🔩 Seawater should never be used directly in the engine jacket water system due to the risk of serious corrosion damage to engine parts.
• 🌡️ Some ships may have a low-temperature (LT) line for cooling smaller machinery, which uses freshwater circulated through various coolers and heat exchangers.

Q & A

What is the primary purpose of a ship's freshwater system?

The primary purpose of a ship's freshwater system is to provide fresh water for drinking and domestic uses, and to cool the ship's engines and machinery without causing corrosion that seawater would introduce.

Why can't seawater be used for cooling engines directly?

Seawater cannot be used directly for cooling engines because it causes corrosion in metals like iron and steel, which are commonly used in ship construction and machinery.

How does the freshwater cooling system differ from the domestic freshwater system?

The freshwater cooling system is designed to absorb heat from the main and auxiliary engines and transfer it to the seawater system, while the domestic freshwater system is for non-industrial uses such as drinking, cooking, and sanitation.

What is the role of the jacket cooling water pumps in the freshwater cooling system?

The jacket cooling water pumps are responsible for circulating fresh water through the engine jackets, where it absorbs heat generated by the combustion process, helping to maintain engine temperature.

What is the function of the high-temperature (HT) line in the freshwater cooling system?

The HT line is a closed-loop system that circulates freshwater through the engine jackets to absorb heat and then redirects the heated water either back to the engine or through a cooler to dispose of the heat.

What is the purpose of the preheater in the HT line?

The preheater in the HT line is used to maintain the jacket water temperature when the engine is running at slow speeds, ensuring efficient heat absorption and engine operation.

How does the jacket water cooler contribute to the cooling process?

The jacket water cooler is part of the HT line and is responsible for transferring the heat absorbed from the main engine to either seawater or freshwater, depending on the ship's configuration, to be eventually released into the sea.

What is the significance of the low-temperature (LT) line in the freshwater system?

The LT line is used for cooling smaller machinery and systems that generate heat but are not directly involved in fuel combustion. It operates as a closed loop, circulating freshwater through various coolers and heat exchangers.

How does the central cooler in the LT line function?

The central cooler, also known as the LT water cooler, is where the freshwater that has absorbed heat from various systems is cooled by seawater, which then carries the heat away and releases it into the sea.

What are some other components that may be connected to the freshwater system?

Other components that may be connected to the freshwater system include air compressors, lubricating oil coolers, intake air coolers for engines, and condensers for refrigeration and air conditioning systems.

Why might the design of the freshwater cooling system vary between different ships?

The design of the freshwater cooling system may vary between ships due to differences in engine types, ship size, operational requirements, and the specific technologies employed in each vessel.

Outlines

00:00

🚢 Freshwater Cooling System on Ships

This paragraph introduces the freshwater system on ships, emphasizing the need for a separate system from seawater due to corrosion and unsuitable use for drinking or washing. It outlines the freshwater cooling system's role in absorbing heat from engines and transferring it to seawater. The main engine jacket cooling water, also known as the high-temperature (HT) line, is highlighted as a closed-loop system starting from the expansion tank, where freshwater is circulated through engine jackets to absorb heat, then redirected through a temperature-controlled valve to either return to the engine or pass through a jacket water cooler. The HT line also includes a preheater for maintaining temperature during slow engine speeds.

05:01

💧 Low-Temperature Freshwater System and Its Applications

The second paragraph delves into the low-temperature freshwater system, which is also a closed loop with an expansion tank and pumps. It serves to cool various auxiliary systems like lubricating oil, intake air for engines, and machinery like air compressors, as well as condensers for refrigeration and air conditioning. After absorbing heat, the freshwater passes through a central cooler, also known as the low-temperature (LT) water cooler, where it transfers heat to seawater before being expelled overboard. The paragraph concludes by noting that the setup can vary between ships and hints at additional related topics to be covered in future episodes.

Keywords

💡Freshwater System

The freshwater system on a ship is a critical component for maintaining the vessel's machinery and supporting the crew's needs. It is designed to provide clean, non-salty water for drinking, washing, and other domestic uses, as well as for cooling the ship's engines. In the video, the freshwater system is divided into two subsystems: the freshwater cooling system and the domestic freshwater system, with the former being the focus of the episode. The freshwater cooling system is essential for preventing corrosion and ensuring the efficient operation of the ship's engines.

💡Seawater Cooling System

The seawater cooling system is used for cooling the engines and washing areas like cargo holds on a ship. However, it is not suitable for direct use in engine jacket water systems due to its corrosive nature on metals like iron and steel, which are commonly used in ship construction. The video script highlights the contrast between seawater and freshwater systems, emphasizing the importance of the freshwater system for protecting the ship's machinery from corrosion.

💡Corrosion

Corrosion refers to the gradual destruction of materials, usually metals, due to chemical reactions with their environment. In the context of the video, corrosion is a significant issue because seawater can cause damage to the ship's metal components. The freshwater system is essential to prevent this corrosion, ensuring the longevity and safety of the ship's structure and machinery.

💡Main Engine Jacket Cooling Water Pumps

These pumps are part of the freshwater cooling system and are responsible for circulating water through the engine jackets. As mentioned in the script, they draw freshwater from the expansion tank and deliver it to the engine cylinders, where it absorbs heat and helps maintain optimal engine temperatures. The operation of these pumps is crucial for the efficient functioning of the engine and the overall performance of the ship.

💡High-Temperature (HT) Line

The HT line, or high-temperature line, is a closed-loop system within the freshwater cooling subsystem. It is designed to absorb heat from the main engine and transfer it to the seawater system. The script describes the HT line as a key feature of the freshwater cooling system, starting from the expansion tank and involving components like the jacket cooling water pumps and the jacket water cooler.

💡Expansion Tank

The expansion tank is a storage reservoir for freshwater in the cooling system. It plays a role in accommodating changes in water volume due to temperature fluctuations. As explained in the video, freshwater from the expansion tank is used by the jacket cooling water pumps to cool the engine, and after circulation, some water returns to the tank, maintaining a closed loop.

💡Jacket Water Cooler

The jacket water cooler is a component of the HT line where the heat absorbed from the main engine by the freshwater is transferred to the seawater system. This process helps to dissipate the heat and keep the engine's temperature within safe operating limits. The script emphasizes the importance of this component in the overall cooling process of the ship's engines.

💡Preheater

A preheater is used in the freshwater cooling system to maintain the jacket water temperature when the engine is running at slow speeds. As mentioned in the script, it is part of the HT line and helps to ensure that the engine does not operate below its optimal temperature range, which is crucial for efficient and safe engine operation.

💡Auxiliary Engines

Auxiliary engines are secondary power units on a ship that support various functions, such as generating electricity or providing power for specific systems. The video script discusses a similar freshwater cooling system for auxiliary engines as for the main engine, highlighting the importance of cooling for all engine types to prevent overheating and ensure reliable operation.

💡Central Cooling System

The central cooling system is an alternative configuration that uses freshwater instead of seawater to cool various machinery and systems on the ship. As described in the script, this system includes a low-temperature freshwater line (LT line) that circulates water through coolers and then through a central cooler, where the heat is transferred to the seawater and eventually released into the sea. This system is an example of how different ship designs may implement the freshwater cooling system.

Highlights

Introduction to the ship's freshwater system, essential for cooling and domestic use on ships.

Explanation of the division between freshwater cooling system and domestic freshwater system.

Discussion on the limitations of using seawater for cooling due to corrosion and unsuitable for drinking or washing.

Introduction to the freshwater cooling system's role in absorbing heat from engines and transferring it to the seawater system.

Description of the main engine jacket cooling water system, also known as the high-temperature (HT) line.

Detail on how the freshwater cooling system maintains engine temperature within the optimal range.

Explanation of the function of the jacket water cooler in the HT line and its connection to the seawater system.

Discussion on the use of preheaters in the HT line to maintain water temperature during slow engine speeds.

Introduction to the auxiliary engines' freshwater cooling system and its similarities to the main engine's system.

Highlight on the importance of not using seawater directly in the engine jacket water system to prevent corrosion.

Description of the low-temperature freshwater line (LT line) for cooling smaller machinery and systems.

Explanation of the central cooling system's use of freshwater instead of seawater in heat exchangers.

Detail on how the central cooler, connected to the seawater cooling system, absorbs heat and disposes it into the sea.

Presentation of a typical setup of the ship's freshwater cooling system and acknowledgment of design variations.

Invitation for audience suggestions on maritime-related topics for future episodes.

Transcripts

hello everyone welcome to another

episode of study call the chief McCoy in

this episode we will be talking about

the ship's freshwater system in the

previous episode we talked about the sea

water cooling system out in the ocean

sea water is the most abundant resource

we can use for cooling the engines and

washing things like the cargo holds and

other stuff but the downside is sea

water causes corrosion in metals like

iron and steel which is basically what

the ship and its machinery is made of

also the crew can't use seawater for

drinking and other domestic things like

taking a shower or washing clothes which

is why ships have a freshwater system

now for the purpose of this discussion

we will divide the freshwater system

into two subsystems the freshwater

cooling system and the domestic

freshwater system in this episode we

will only tackle the freshwater cooling

system let's leave the domestic or the

next episode

and also the system that we will discuss

today and for the succeeding episodes

will be for ships

running on diesel engines ships driven

by steam turbines have a slightly

different configuration so that's going

to be a topic for a future episode

now the freshwater cooling system is

used for absorbing the heat from the

main and auxiliary engines and transfer

it to the seawater system and eventually

they're supposed to heat out into the

sea depending on the ship's design a low

temperature line can also be installed

for cooling smaller machinery like the

air compressors but more on that later

perhaps we can say that the main feature

the freshwater cooling system is the

main engine

Jagat cooling wine otherwise known as

the HT or high-temperature line the HT

line is a closed-loop system so

technically there really isn't the

beginning or end but anyway let's start

from the expansion tank which of course

contains fresh water from there fresh

water is suction by the jacket cooling

water pumps and then delivers it to the

main engine cylinders the cylinders have

these jackets around the top part

including the cylinder cover and the

exhaust valves which is basically the

area around the combustion chamber where

obviously the heat is generated when the

engine burns fuel now the freshwater

flows through these jackets and absorbs

the heat from the metal maintaining the

temperature at around 83 to 85 degrees

Celsius after passing through the

jackets the water leaves the main engine

and goes to a junction where some of it

goes back up to the expansion tank while

some of it passes through a temperature

controlled three-way valve which then

redirects the water flow to either go

back to the main engine or pass through

the jacket water cooler where the heat

absorbed from the main engine will

eventually be disposed

I'll to see the HT line is also fitted

with a preheater which is used to

maintain the jacket water temperature

when the engine is running at slow

speeds like when the ship is

nuvaring

[Music]

a similar although smaller system is

also installed for the auxiliary engines

now based on what we have just discussed

it's pretty obvious why seawater should

never be used directly as the cooling

medium in the engine jacket water system

acid will cost serious damages to the

engine parts mainly due to corrosion as

mentioned in the previous episode the

jacket water cooler can use either

seawater or freshwater as the cooling

needed depending on whether the ship is

installed with a direct sea water

cooling system or a central cooling

system now earlier I have also mentioned

that a low temperature freshwater line

can also be installed for cooling

smaller machinery and other systems this

is the case if the ship is installed

with a central cooling system where

instead of sea water passing through the

various heat exchangers this system uses

fresh water similar to the HT line this

LT or a low temperature line this a

closed loop has an expansion tank and

gets the water circulated through the

system using pumps the fresh water

passes through all the coolers in the

various auxiliary systems like

lubricating oil and intake air for the

main and auxiliary engines and also for

machinery like the air compressors as

well as for the different condensers

like in the steam return line and the

refrigeration and air conditioning plan

basically everything that needs cooling

down that is within the low temperature

range which is to say anything that

generates heat but not directly as a

result of fuel combustion now after the

freshwater has absorbed the heat from

everything in the system to pass through

the central cooler which is sometimes

also known as the LT or a low

temperature water cooler which is

directly connected to the sea water

cooling system in here the heat will be

absorbed by the seawater and eventually

pull out through the overboard

and out into the sea

[Music]

what I am showing you is a typical setup

of the ship's freshwater cooling system

but of course the design or arrangement

may vary a little bit for every ship

there are also a few items which are

connected to the freshwater system which

I did not include yet these those items

will be the topics of future episodes if

you have any other maritime related

topics which you are interested in or

want me to discuss feel free to write it

down in the comment section below

but for now class dismissed

you