Question 52Gas Turbine - Assistant Engineer

The correct answer is C) Power turbine cooling. The 9th stage bleed air from the GE LM2500 gas turbine is used for power turbine cooling. The power turbine is responsible for extracting power from the high-pressure turbine exhaust to drive the compressor. Directing the high-pressure, high-temperature 9th stage bleed air to the power turbine helps cool the blades and other components, improving efficiency and preventing thermal damage. The other answer choices are incorrect because: A) is for the high-pressure turbine, not the power turbine; B) is for the compressor balance piston, not the power turbine; and D) is for sump pressurization and cooling, not the power turbine.