Types of Fins Used in Air-Cooled Heat Exchangers (ACHEs)
Fins are critical components in air-cooled heat exchangers, significantly enhancing heat transfer efficiency by increasing the surface area exposed to cooling air. Different fin types are used based on application requirements, thermal performance needs, and environmental conditions.
1. Basic Fin Types
A. Plain Fins (Flat Fins)
- Design: Simple, flat, continuous metal strips
- Advantages:
- Low cost
- Easy to manufacture
- Low air-side pressure drop
- Disadvantages:
- Lower heat transfer efficiency compared to enhanced fins
- Applications:
- Low-fouling environments
- General-purpose cooling
B. Serrated Fins (Cut Fins)
- Design: Plain fins with periodic cuts/serrations
- Advantages:
- Better turbulence → higher heat transfer
- Good balance between performance and pressure drop
- Disadvantages:
- More susceptible to fouling than plain fins
- Applications:
- Petrochemical plants
- Power generation
C. Louvered Fins
- Design: Angled cuts create small deflectors
- Advantages:
- Excellent heat transfer (disrupts boundary layer)
- Compact design
- Disadvantages:
- Higher air-side pressure drop
- Prone to clogging in dirty environments
- Applications:
- Automotive radiators
- HVAC systems
D. Wavy Fins
- Design: Corrugated/undulating surface
- Advantages:
- Improved heat transfer via increased turbulence
- Lower fouling tendency than serrated fins
- Disadvantages:
- Moderate pressure drop increase
- Applications:
- Industrial process cooling
- Compressed air systems
E. Pin Fins
- Design: Discrete pins protruding from tube surface
- Advantages:
- Very high heat transfer in low-velocity air
- Good for omnidirectional airflow