Clean air flows into a gas turbine regenerator from:

• A. the inlet air pre-filter
• B. the combustor
• C. the gasifier
• D. the compressor outlet

Answer: (D)

In a gas turbine with a regenerator, the incoming air is heated by exhaust heat to boost efficiency, so the air entering the regenerator on the cold side must be the air that has just been compressed. That compressed, clean, pressurized air comes from the compressor outlet, which has already passed through filtration and compression stages. The other sources don’t fit this path: the inlet pre-filter is before compression, not after; the combustor’s flow is the hot exhaust rather than the intake for heating; a gasifier isn’t part of a standard turbine regenerator loop. So clean air flows into the regenerator from the compressor outlet.