Nitrogen plays a critical role in enhancing the safety of aircraft fuel tanks by reducing the risk of fire and explosion. This is achieved through a process known as "fuel tank inerting," where nitrogen is used to displace oxygen within the fuel tank, thereby creating an environment that is less likely to support combustion.

Fire Triangle and Combustion Prevention

Combustion requires three elements: fuel, oxygen, and an ignition source. By introducing nitrogen into the fuel tank, the oxygen concentration is reduced to a level that is insufficient to support combustion. This effectively eliminates one of the key components of the "fire triangle," thereby minimizing the risk of fire or explosion.

Nitrogen Generation Systems

Modern aircraft, such as the Boeing 737, are equipped with Nitrogen Generation Systems (NGS) that produce nitrogen-enriched air (NEA) to blanket the fuel tanks. These systems use air separation modules to extract nitrogen from the air, which is then pumped into the fuel tank. For example, the Boeing 737 NGS reduces the oxygen content in the fuel tank to levels that are non-flammable.

Benefits of Nitrogen Inerting

Reduced Fire Risk: By lowering the oxygen concentration, nitrogen inerting significantly reduces the risk of fire and explosion in fuel tanks.
Prevention of Oxidation: Nitrogen also helps prevent the oxidation and degradation of fuel, maintaining its quality and extending its usable life.
Corrosion Prevention: The inert environment created by nitrogen reduces the risk of corrosion in the fuel tank and its associated components.

Practical Applications

Commercial Aircraft: Systems like the On-Board Inert Gas Generation System (OBIGGS) are used in commercial aircraft to continuously blanket fuel tanks with nitrogen-enriched air, ensuring safety during flight.
Helicopters: Similar systems are employed in helicopters to protect fuel tanks against explosion risks. These systems are lightweight and reliable, providing continuous protection without adding significant weight.In summary, nitrogen is a crucial element in aerospace fuel tank safety. By displacing oxygen and creating an inert environment, nitrogen significantly reduces the risk of fire and explosion, ensuring the safety and reliability of aircraft operations.