Central Cooling System:
One of the most common systems is central cooling. Fresh water is here used in a closed circuit to cool down the engine room machineries. The fresh water returning from the heat exchanger after cooling the machineries is further cooled by sea water in seawater cooler.
In central cooling systems the seawater is used as a cooling media in large seawater cooled heat exchangers to cool the fresh water of the closed circuit. They are the central coolers of the system.
The fresh water system can be a mixed system; the heat from all the different machineries and other components that need cooling is mixed together in one flow. This is the easiest system to install and regulate, but needs some more cooling area than a split system.
In a split system the low temperature (LT) circuit is used for low temperature zone; hence its temperature is lower than the high temperature (HT) circuit. The LT circuit comprises of all auxiliary systems. The HT circuit mainly comprises of jacket water system of the main engine where the temperature is quite high.
High Temperature Circuit:
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
Low Temperature Circuit:
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
Temperature Control:
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
Fresh Water Cooling System:
Ø A clean system with reduced requirements regarding cleaning and maintenance.
Ø Less “wear” of pipes and valves, therefore less maintenance cost.
Ø Less investment of cost as pipes need not be made for seawater usage.
Ø Reduced number of valves made of expensive materials.
Ø Constant to near constant temperature level of cooling medium means easier temperature control of air and lube oil coolers for main and auxiliary engines.
Ø No condensate on air side, reducing air fouling, owing to the higher and constant temperature for main engine air coolers. Cleaner air coolers compensate for higher cooling water temperature.
Ø No cold starting of main engine, since the whole system is kept at warm temperature when the ship is in port.
Ø Constant running condition for the main engine as regards to cooling water, lube oil and air.
Ø Less wear of cylinders liners, as consequences of running condition – no cold corrosion/startup.
Ø Greater reliability of services offered by the central cooling system is important for an unmanned engine room.
Disadvantages:
Ø Initial high cost.
Ø Limitation of lower temperature, especially for main engine air cooler, also during high sea water temperature.
Central Cooling System:
One of the most common systems is central cooling. Fresh water is here used in a closed circuit to cool down the engine room machineries. The fresh water returning from the heat exchanger after cooling the machineries is further cooled by sea water in seawater cooler.
In central cooling systems the seawater is used as a cooling media in large seawater cooled heat exchangers to cool the fresh water of the closed circuit. They are the central coolers of the system.
The fresh water system can be a mixed system; the heat from all the different machineries and other components that need cooling is mixed together in one flow. This is the easiest system to install and regulate, but needs some more cooling area than a split system.
In a split system the low temperature (LT) circuit is used for low temperature zone; hence its temperature is lower than the high temperature (HT) circuit. The LT circuit comprises of all auxiliary systems. The HT circuit mainly comprises of jacket water system of the main engine where the temperature is quite high.
High Temperature Circuit:
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
Low Temperature Circuit:
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
Temperature Control:
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
![*](file:///C:/Users/R/AppData/Local/Temp/msohtmlclip1/01/clip_image001.gif)
Fresh Water Cooling System:
Ø A clean system with reduced requirements regarding cleaning and maintenance.
Ø Less “wear” of pipes and valves, therefore less maintenance cost.
Ø Less investment of cost as pipes need not be made for seawater usage.
Ø Reduced number of valves made of expensive materials.
Ø Constant to near constant temperature level of cooling medium means easier temperature control of air and lube oil coolers for main and auxiliary engines.
Ø No condensate on air side, reducing air fouling, owing to the higher and constant temperature for main engine air coolers. Cleaner air coolers compensate for higher cooling water temperature.
Ø No cold starting of main engine, since the whole system is kept at warm temperature when the ship is in port.
Ø Constant running condition for the main engine as regards to cooling water, lube oil and air.
Ø Less wear of cylinders liners, as consequences of running condition – no cold corrosion/startup.
Ø Greater reliability of services offered by the central cooling system is important for an unmanned engine room.
Disadvantages:
Ø Initial high cost.
Ø Limitation of lower temperature, especially for main engine air cooler, also during high sea water temperature.
Few Figure for Easy Understanding:
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Links:
Thank you so much. But can you update the photo of HT Circuit, LT Circuit, Temp Controle section? Some photos are not showing.
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