Marine Tubular Heat Exchangers: The Core of Efficient and Reliable Ship Thermal Management

In marine systems, heat exchangers are critical components for ensuring the safe operation of power plants and auxiliary equipment. Tubular heat exchangers, due to their simple structure, durability, and adaptability, are one of the most widely used heat exchange devices in the marine industry. This article will briefly introduce their operating principles, characteristics, and common applications.

What is a tubular heat exchanger?
A tubular heat exchanger consists of a bundle of metal tubes (usually made of copper alloy, stainless steel, or titanium) housed in a cylindrical shell. Two fluids (such as seawater and freshwater, lubricating oil, or fuel oil) flow through the tubes, exchanging heat through the tube walls to achieve heating or cooling.

Operating Principle
Shell-side and Tube-side: One fluid flows within the tubes (the tube side), while the other flows in the shell space outside the tubes (the shell side).

Counterflow Design: Counterflow is often used (flows flow in opposite directions) to improve heat transfer efficiency.

Heat Transfer: The hot fluid transfers heat to the cold fluid through the tube walls, achieving temperature regulation.

Key Features
Sturdy Structure: High-pressure and corrosion-resistant, suitable for harsh ship environments (such as vibration and salt spray).

Easy Maintenance: Tube bundles can be cleaned or replaced individually, reducing maintenance costs.

Wide Adaptability: Adaptable to different media through material selection (e.g., titanium tubes for seawater corrosion resistance).

High Reliability: No moving parts, low failure rate, and long service life.

Typical Applications
Engine Cooling: Cools diesel engine jacket water and lubricating oil.

Fuel Heating: Heats heavy fuel oil to reduce viscosity and ensure combustion efficiency.

Central Cooling System: Serves as the core unit for seawater-freshwater heat exchange.

Air Conditioning and Refrigeration: Part of the refrigerant circulation system for ship air conditioning.

Selection Considerations
Material Selection: Pipe materials are determined based on the corrosiveness of the media (e.g., seawater requires corrosion-resistant materials).

Fouling Factor: Consider the water's susceptibility to fouling and allow for a clean margin during design.

Space Layout: Compact design accommodates the limited space in the engine room.