What is surge in gas turbine?

Answer 1

Surging in gasturbine means that the pressure at the delivery end of the gas turbine compressor becomes very high (as a result of reduced flow at the compressor outlet). When this happens, the compressor pressure at the delivery end increases as the flow decreases upto an extent after which the pressure does not increase and there is a flow reversal. This flow reversal releases the sudden pressure that developed on account of reduced flow. The flow reversal is accomplanied with a loud noise and tremendous vibration. Surging affects the whole machine and if it is of high magnitude, the gas turbine can be ripped apart. Anti-surge devices (Bleed valves) are installed which do not allow the flow to reduce even on low speeds and keep a certain air flow from the compressor during times of low air requirement (startup and shutdown) Surging in gasturbine means that the pressure at the delivery end of the gas turbine compressor becomes very high (as a result of reduced flow at the compressor outlet). When this happens, the compressor pressure at the delivery end increases as the flow decreases upto an extent after which the pressure does not increase and there is a flow reversal. This flow reversal releases the sudden pressure that developed on account of reduced flow. The flow reversal is accomplanied with a loud noise and tremendous vibration. Surging affects the whole machine and if it is of high magnitude, the gas turbine can be ripped apart. Anti-surge devices (Bleed valves) are installed which do not allow the flow to reduce even on low speeds and keep a certain air flow from the compressor during times of low air requirement (startup and shutdown)