Fixed CO2 (carbon dioxide) systems, also known as CO2 fire suppression systems, are automatic fire protection systems used to extinguish fires in enclosed spaces on ships, industrial plants, and other facilities. They are particularly effective for suppressing fires involving flammable liquids, electrical equipment, and machinery, where water or other traditional firefighting agents might not be suitable or could cause further damage.

Here’s how fixed CO2 systems typically work:

1. CO2 Storage Tanks
   The system includes one or more high-pressure storage tanks filled with liquid CO2. The CO2 is stored under pressure, typically between 700 to 850 psi (pounds per square inch) or more, depending on the application.
2. Detection and Activation
   When a fire is detected in the protected space, a fire detection system (such as heat or smoke detectors) triggers the release of CO2. The detection system must quickly sense the fire to initiate the discharge promptly.
3. CO2 Release
   Upon activation, the CO2 is rapidly released from the storage tanks. The CO2 expands from a liquid to a gas state as it exits the tank, resulting in a significant increase in volume.
4. Distribution and Suppression
   The released CO2 is distributed through a network of pipes and nozzles within the protected area. The CO2 gas displaces oxygen from the fire zone, reducing the oxygen concentration to a level where combustion cannot be sustained, effectively extinguishing the fire.
5. Safety Measures
   To prevent personnel injury, fixed CO2 systems are designed with safety delays and warning alarms to allow occupants to evacuate the area before the CO2 discharge occurs.

Fixed CO2 systems are commonly used in various settings, including:

• Marine: Onboard ships, fixed CO2 systems are employed to protect machinery spaces, engine rooms, cargo holds, and other critical areas.
• Industrial: In industrial facilities, these systems are used to protect electrical switch rooms, control rooms, generator rooms, and other enclosed spaces where a fire could cause significant damage.
• Power Generation: Fixed CO2 systems are often installed in power plants to protect turbine enclosures and generator rooms.
• Data Centers: Data centers use CO2 systems to protect valuable IT equipment and electronics.

It’s important to note that CO2 is a colorless and odorless gas, and its release in high concentrations can be hazardous to human health. Therefore, personnel must be trained to handle the system safely and evacuate the protected area when the CO2 system is activated. Fixed CO2 systems require regular maintenance and inspection to ensure their reliability and effectiveness in fire suppression. Additionally, due to environmental concerns, some facilities are transitioning to alternative fire suppression agents that have lower environmental impacts, but CO2 remains a widely used and effective fire suppression option.