Supressão de incêndio de dióxido de carbono: Introdução do sistema principal

Alta pressão dióxido de carbono fire extinguishing system is a kind of gas fire extinguishing system which uses liquid carbon dioxide to store, gasify, and then release to extinguish fire.

It plays an irreplaceable role in specific places due to its unique advantages. Contudo, there are strict limitations on its use. The following is a comprehensive analysis and description of the system:

Core Working Principles

It achieves the purpose of extinguishing class A, B, C, and E fires by rapidly releasing a large amount of liquid CO₂ to the protected area, vaporising it and rapidly reducing the concentration of oxygen (asphyxiation) and absorbing a large amount of heat (cooling) ao mesmo tempo.

Core Strengths (Características principais)

The main reason why we chose the high-pressure carbon dioxide fire suppression system is that it has the following core advantages (main features):

• Não condutor: Perfect for electrical fires.
• Sem resíduo: completely evaporates after extinguishing the fire, no damage to precision equipment, relíquias culturais, or data carriers.
• Limpar limpo, nenhum resíduo: leaves no chemical residue to clean up.
• Environmental properties: Non-destructive to the ozone layer (PDO = 0).
• Suitable for deep-seated fires: able to penetrate certain materials.
• Suitable for flammable liquids/gases: fast vapour suppression.
• facilmente Distribuído.
• Custo-beneficio: Low filling cost of carbon dioxide fire extinguishing agent.
• Storage in high-quality seamless carbon steel bottles.

High-pressure CO2 System Key Components

The CO2 fire suppression system has the following key components:

• CO₂ storage unit: High-pressure cylinder (typically 20-70 Barra) for liquid CO₂.
• Dispositivo de ativação: elétrico, pneumatic, or manual activation of the valve.
• Release pipe network and nozzle: Deliver and uniformly spray CO₂ extinguishing agent to the protected area.
• Detection and alarm system: fire detectors linked to audible and visual alarms (people must be evacuated in advance!).
• Pressure switch/weighing device: Monitoring of CO₂ storage.

Applicable Fire Types

This product is suitable for Class A, B, C, e E dispara:

• Class A surface fires: Fires on the surface of partially solid material (deep-seated fires require sufficient impregnation time).
• classe B: Flammable liquids (oils, solvents, tintas) and gas fires.
• classe C: Combustible gas fires.
• classe E: Fires in electrical equipment (transformadores, servers, quadros).

Typical Areas of Application

Typical applications of high-pressure carbon dioxide, subject to “unmanned/rapid and complete evacuation”, are listed below:

Electrical and Electronic Equipment Room

• Data Centres/Server Rooms: Protect sensitive computer servers, network equipment, storage devices, etc., as CO₂ is electrically non-conductive and leaves no residue to damage electronic components.
• Telephone exchange rooms: Protect critical communications equipment.
• Control Room/PLC Room: Protects industrial process control systems, programmable logic controllers, etc.
• Distribution rooms/substations: Protection of electrical equipment such as high-voltage switchgear, transformadores (especially indoor or dry-type transformers).

Flammable Liquid and Combustible Gas Fire Risk Areas

• Paint booths/spray booths: Solvent vapours are flammable, CO₂ quickly extinguishes surface fires and suppresses vapours.
• Oil-immersed transformer rooms: Effective in extinguishing transformer oil fires (subject to selection of suitable design and application).
• FLAMMABLE LIQUID STORAGE TANKING AREA/PUMPHOUSE: Protects areas where petrol, diesel, lubrificantes, solvents, etc., are stored or delivered (often with local application systems).
• Partial area of a petrochemical installation: Protection of specific equipment or small spaces.
• Laboratório: An experimental area where flammable solvents or gases are used.

Sites that need to be Protected From Water Damage or Chemical Residue Damage

• Libraries/Archives/Museums: Protect valuable books, documents, artefacts, works of art from damage caused by water or chemical fire extinguishing agents. Contudo, the safety of personnel requires special attention.
• Precision Instrument Room: Protects expensive and water-resistant precision instruments and equipment.
• Quarto limpo: Por exemplo, semiconductor manufacturing, pharmaceuticals, and other places that require a high level of environmental cleanliness, CO₂ residue-free characteristics are very important.

Engine Compartment and Machinery Space

• Ship’s engine/pump bays: Carbon dioxide is a very common fire suppression system on ships to protect main engines, geradores, boilers, fuel pumps, etc.
• Power plant turbine rooms: Protection of turbine-generator units (especially hydrogen-cooled units) and their lubrication systems.
• Hangar: Sometimes used to protect the engine compartment or a specific area of an aircraft.

Industrial Processing Equipment

• Prensas de impressão: Protection of large, high-speed printing equipment and its inks and solvents.
• Plastic injection moulding/extrusion equipment: Protect areas involving hot plastics and where combustible dust or gases may be generated.
• Dust collection systems: Protection of dust collectors, pipework, etc.
• Quenching Oil Tanks: Tanks for the protection of oil in heat treatment.
• Reactor/Pressure Vessel: Protects some chemical production equipment.

Other Specialised Sites

• Room hoods and ducts: specialised high-pressure CO₂ systems for extinguishing cooking grease fires.
• Flammable solid storage areas: Specific types of solid fires.

Important Notes and Limitations

• Safety of personnel is a primary concern: CO₂ extinguishes fires by diluting oxygen. It is fatal to unprotected personnel when the concentration reaches the extinguishing concentration (usually 34 per cent or more). It is important to ensure that personnel have completely evacuated the protected area before the system is activated! In these locations, we have the option of using other safe gaseous extinguishing agents (such as the inert gases IG-541, IG-55, IG-01, ou Heptafluoropropane FM200) or non-gas systems.
• High-pressure storage: Requires pressure-resistant bottles and piping, high installation and maintenance requirements.
• Low Temperature Effects: Low temperatures are generated when spraying, which may cause cold shock to some precision equipment or materials.
• e-ignition potential: For some deep-seated fires or shadow fires, sufficient impregnation time is required to prevent re-ignition.
• Space Containment Requirements: A total flooding system requires good containment of the protected area to maintain fire suppression concentrations.
• Environmental impact: CO₂ is the main greenhouse gas, and its high GWP value is its main disadvantage in terms of environmental protection.

Personnel Safety Measures

When we design a high-pressure carbon dioxide fire suppression system, we must include the following safety measures:

• Pre-alarm system: Sound and light alarms (not evacuation alarms) are activated immediately after the fire is confirmed, prompting personnel to prepare for evacuation.
• Delayed release (30-60 segundos): delayed spraying after alarm, leaving golden time for evacuation.
• Emergency start-stop button: set at the entrance to the protected area, with the possibility of manually aborting the release during the delay phase.
• Warning signs: Clearly labelled “CO₂ fire extinguishing system”, “Evacuate before release”, “High concentration of CO₂”, etc.
• Ventilation and exhaust: After extinguishing the fire, forced ventilation is required to remove residual CO₂ and reduce the effects of low temperatures before personnel can enter.

Consideration of Alternative Options

When the safety of personnel is the primary consideration, a safer clean gas extinguishing agent should be used for areas where the protection of personnel is likely to be present:

• Inert gases: IG-541 (Ar/N₂/CO₂), IG-55 (N₂/Ar), IG-01 (Ar) – extinguishes fires by physically diluting the oxygen (down to approx. 12.5 per cent) and is relatively safe.
• Chemical gas: heptafluoropropano (HFC-227ea/FM200) – low extinguishing concentrations (typically <10%), baixa toxicidade.
• Water-based alternatives: fine water mist, high-pressure water spray systems, etc.

Design Codes and Standards

The design of CO2 extinguishing systems needs to follow international standards and national codes:

• International: NFPA 12 (National Fire Protection Association Standard).
• China: GB 50193 Design Code for Carbon Dioxide Fire Extinguishing Systems, GB 50263 Code for Construction and Acceptance of Gaseous Fire Extinguishing Systems.
• Other areas: subject to local fire codes.

Conclusão

High-pressure CO2 fire extinguishing systems are great for protecting high-value, unoccupied locations that are vulnerable to water/residue damage (e.g., equipamento eletrônico, flammable liquids areas, treasure vaults), but the risk of fatal asphyxiation dictates that they should only be used when “absolutely safe evacuation of personnel is assured”.

We must do the following in selecting and applying this system:

• Prioritise the safety of people’s lives and strictly comply with evacuation and alarm requirements.
• Rigorous design by professional fire engineers based on specific risks, space characteristics, and codes.
• Regular maintenance and personnel training (especially emergency operation and evacuation drills).