Gas Cooler For Natural Gas Compression Unit
A natural gas compressor gas cooler is a high-pressure heat exchanger installed on reciprocating / centrifugal natural gas compressors. It is divided into intercooler (inter-stage cooler) and aftercooler (final-stage cooler).
Hot compressed natural gas flows inside tubes, transferring heat to cooling medium (ambient air / circulating cooling water). It lowers gas temperature, reduces compression power, separates condensate water & compressor lube oil, prevents hydrate formation and protects downstream pipelines & equipment.
① Intercooler (Inter-stage Gas Cooler)
Installed between compression stages for multi-stage compressors
Cool high-temperature gas discharged from the previous stage before entering next compression
Reduce gas density, cut compression power consumption significantly
Typical temperature drop: 140~180°C → 40~55°C
② Aftercooler (Final Gas Cooler)
Installed after the last compression stage
Cool high-pressure natural gas before entering pipelines, storage or CNG filling system
Condense water vapor and carry-over lubricating oil; separate via downstream separator
Control gas outlet temperature to meet pipeline transportation requirements
Two Main Structural Forms
A) Air-Cooled Gas Cooler (Dry Air Cooler / Fin-Fan ACHE)
Most popular for remote compressor stations, CNG stations, well sites
Tube side: High-pressure natural gas
Air side: Ambient air driven by axial fans
Structure: Horizontal / V-type finned tube bundle; frame hot-dip galvanized
Fans: VFD control according to gas outlet temperature
Standard tube material: Carbon steel; 316L / 2205 duplex steel for corrosive raw gas (H₂S, chloride)
B) Shell & Tube Water-Cooled Gas Cooler
Used for fixed stations with stable cooling water supply
Gas flows inside tubes; cooling water runs on shell side
Higher heat transfer efficiency, achieves lower gas outlet temperature
Floating head / U-tube design absorbs thermal expansion; complies with ASME / TEMA pressure vessel standards
Application Sites
CNG filling stations & CNG mother/daughter stations
Natural gas pipeline compressor stations
Oil & gas wellhead compression units
Biogas / landfill gas boosting compressors
Industrial natural gas booster systems
Power plant fuel gas compression skids
