Charge Air Cooler For Offshore Platform Diesel Engine Cooling System
Charge air Cooler for Offshore Platform Diesel Engine Cooling System
Core Function
Installed between turbocharger outlet & engine intake manifold, cooling high-temp compressed boost air:
Turbo-compressed air rises to 180~220℃, CAC cools down to 40~50℃, boost air density ↑, more oxygen into cylinder
Reduce fuel consumption, lower NOₓ exhaust emission per IMO offshore regulation
Cut engine thermal load, avoid abnormal detonation & overheating, extend diesel service life
Offshore Special Working Condition
Severe salt spray, high humidity & corrosive offshore marine atmosphere
Dual-circuit cooling design widely adopted: Closed fresh water intermediate loop + open seawater final cooling.
Independent CAC cooling circuit with thermostat (keep coolant ≥30℃ to avoid condensation dew inside core)
Main Structure & Material Selection (Offshore Anti-corrosion Standard)
| Component | Standard Offshore Material | Advantage |
|---|---|---|
| Cooling Tube | CuNi 90/10 /70/30 Copper-nickel, Titanium tube | Excellent seawater salt corrosion resistance |
| Fin | Tinned copper fin / coated aluminum fin | High heat transfer, anti-salt fog corrosion |
| Tube Sheet | Naval brass / carbon steel with anti-corrosion coating | Anti-pitting corrosion under alternating wet-dry |
| Shell/End Cover | Cast iron + epoxy anticorrosive paint | Offshore salt mist protection |
Structure type: Tube & Fin (most popular for offshore diesel CAC)
Hot charge air flows outside finned tubes; cooling fresh water circulates inside tubes for cross-flow heat exchange.
Two Typical Cooling Circuits for Offshore Platform
Scheme 1: Indirect Fresh Water Cooling (Mainstream Offshore Type)
Seawater → plate heat exchanger → cool closed fresh water → fresh water pump → CAC tube side → back to fresh water tank
Advantage: Seawater never enters CAC core, greatly reduce tube corrosion & blockage, preferred for offshore critical generator diesel
Scheme 2: Direct Seawater Cooling (Cost-saving small unit)
Seawater directly passes through CAC pipeline, only used for low-power auxiliary diesel on unmanned platform
Common Fault & Maintenance for Offshore CAC
Air side fouling: Salt dust & oil sludge block fins → air pressure drop rises, engine power derate → regular high-pressure air washing
Water side scale/corrosion: Seawater scaling or tube pinhole leakage → chemical pickling or tube plugging replacement
Dew condensation inside core: Too low cooling water temp → adjust CAC circuit thermostat to raise inlet coolant temp
Matching Applicable Diesel Brands for Offshore Platform
Caterpillar, MAN, Wärtsilä, DEUTZ, Mitsubishi, Yanmar offshore generator diesel series
