HEAT EXCHANGER ON VESSELS

 HEAT EXCHANGER ON VESSELS.

Heat exchangers on vessels are essential for maintaining temperature control in various shipboard systems. 

They transfer heat between two fluids without mixing them, ensuring efficient operation of engines, generators, and auxiliary equipment. 

Here’s an overview of the main types and their applications on ships:

A. Types of Heat Exchangers on Vessels

 1. Shell and Tube Heat Exchangers

 • Most common type on ships.

 • Consists of a shell (outer vessel) and multiple tubes inside.

 • One fluid flows through the tubes while another flows around them inside the shell.

 • Used in main engine cooling systems, lube oil coolers, and steam condensers.

 2. Plate Heat Exchangers

 • Made up of multiple thin plates with narrow gaps for fluid flow.

 • More compact and efficient than shell and tube exchangers.

 • Common in fresh water generators, auxiliary engine coolers, and air conditioning systems.

 3. Air Coolers (Fin-Fan Exchangers)

 • Use fans to cool fluids by forcing air over finned tubes.

 • Found in charge air cooling systems for diesel engines and refrigeration systems.

 4. Fresh Water Generators (Evaporators)

 • Use heat from engine cooling water or steam to evaporate seawater, producing fresh water.

 • A type of heat exchanger that operates under vacuum conditions to lower the boiling point of seawater.

 5. Condensers

 • Convert steam back into water by removing heat.

 • Found in steam propulsion plants, refrigeration systems, and air conditioning units.

 6. Oil Coolers

 • Cools lubricating oil or hydraulic oil using seawater or fresh water.

 • Prevents oil degradation and ensures proper lubrication.

B. Common Applications on Ships

 • Main Engine Cooling: Seawater cools fresh water, which in turn cools the engine.

 • Lube Oil Cooling: Prevents overheating of lubricants in engines and gearboxes.

 • Charge Air Cooling: Reduces temperature of compressed air before entering the engine for better efficiency.

 • Fresh Water Generation: Converts seawater into drinkable water for crew and boilers.

 • Refrigeration and HVAC: Maintains cargo and accommodation temperatures.

C. Maintenance Considerations

 • Regular cleaning to prevent fouling and scaling (especially with seawater-cooled exchangers).

 • Monitoring for leaks and corrosion, especially in plate-type exchangers.

 • Ensuring proper flow rates and pressure levels for efficient heat transfer.