How many spark ignitors are used in the ignition system?

How many spark ignitors are used in the ignition system?

• A. One
• B. Two
• C. Three
• D. Four

Answer: (B)

Two spark ignitors are used to ensure reliable light-off across the combustor under different operating conditions. A single igniter can fail or produce an uncertain spark, and the lean, fast-changing fuel-air mixture in a gas turbine can be difficult to ignite consistently. Placing two igniters in separate zones provides redundancy and better ignition coverage, so if one igniter fouls, weakens, or is off, the other can still ignite the mixture. In practice, the ignition system is designed to energize both igniters during start to guarantee a dependable light-off. While some designs might use more for extra redundancy, two is the standard choice for reliable ignition in most systems.

Two spark ignitors are used to ensure reliable light-off across the combustor under different operating conditions. A single igniter can fail or produce an uncertain spark, and the lean, fast-changing fuel-air mixture in a gas turbine can be difficult to ignite consistently. Placing two igniters in separate zones provides redundancy and better ignition coverage, so if one igniter fouls, weakens, or is off, the other can still ignite the mixture. In practice, the ignition system is designed to energize both igniters during start to guarantee a dependable light-off. While some designs might use more for extra redundancy, two is the standard choice for reliable ignition in most systems.