Types of Heat Exchangers
Heat exchangers come in many designs, but the main categories are:
By Flow Configuration
- Parallel Flow: Both fluids enter the exchanger at the same end and flow in the same direction to the other end.
- Counter Flow: Fluids enter the exchanger from opposite ends and flow in opposite directions. This is the most efficient design, as it maintains a higher average temperature difference across the entire length of the exchanger.
- Cross Flow: The fluids flow perpendicular to each other. This is common in car radiators and air conditioner coils.
By Design and Construction
- Shell and Tube: The most versatile and common type for high-pressure applications. One fluid flows through a bundle of tubes, while the other fluid flows over the tubes (within a surrounding “shell”).
- Plate: Uses multiple, thin, corrugated metal plates stacked together to create channels for the fluids to flow through. They are very compact and efficient.
- Finned-Tube: Used when one fluid is a gas (like air) and the other is a liquid. Fins are added to the tube side exposed to the gas to dramatically increase the surface area and improve heat transfer. Your car radiator and air conditioner condenser are examples.
- Double-Pipe (or Hairpin): The simplest type, consisting of one pipe inside another. One fluid flows through the inner pipe and the other in the annular space between the two pipes.