What Is The Purpose of A Dry Cooler in A Gas Compressor System?

In a gas compressor system, a dry cooler serves as an air-cooled heat rejection device whose primary purpose is to remove waste heat from process and auxiliary cooling circuits without consuming water.

Core Functions of a Dry Cooler in Gas Compressor Systems

1. Heat Removal from Cooling Media
   Dry coolers dissipate heat from:

   Heat is transferred from the circulating fluid to ambient air through finned tube heat exchanger coils, driven by axial fans.

• Compressor jacket water

• Lube oil cooling circuits

• Intercooler and aftercooler secondary loops

• Seal gas or bearing cooling systems (via closed-loop glycol/water)

2. Water-Free Cooling Solution
   Unlike cooling towers, dry coolers:

   This makes them particularly suitable for oil & gas facilities, compressor stations, and remote sites with limited water availability.

• Do not require makeup water

• Eliminate evaporation losses, drift, and blowdown

• Avoid scaling, biological growth, and water treatment

3. Stable and Clean Closed-Loop Operation
   Dry coolers operate in a closed-loop system, typically using water or water/glycol mixtures. This:

• Protects compressors and auxiliaries from contamination

• Reduces corrosion risk

• Improves long-term reliability of critical rotating equipment

4. Support for Variable Operating Conditions
   With fan speed control (EC or VFD-driven fans), dry coolers can:

• Maintain stable outlet temperatures

• Adapt to varying compressor loads and ambient conditions

• Reduce electrical power consumption during part-load operation

5. Integration with Heat Recovery or Hybrid Cooling
   In some compressor installations, dry coolers:

• Enable free cooling during low ambient temperatures

• Work in conjunction with heat recovery systems (e.g., for space heating or process use)

• Serve as backup heat rejection when water-based systems are offline

Typical Applications in Gas Compressor Systems

• Natural gas pipeline compressor stations

• Process gas compressors in refineries and petrochemical plants

• Biogas and hydrogen compression systems

• Containerized or skid-mounted compressor packages

Summary

The primary purpose of a dry cooler in a gas compressor system is to efficiently and reliably reject compressor waste heat using ambient air, while minimizing water use, maintenance, and operational complexity. This contributes directly to improved system reliability, lower operating costs, and compliance with environmental constraints.