In a gas turbine cycle, the regenerator's role is to

• A. Re-circulate the exhaust gases back through the compressor
• B. Improve the efficiency of the turbine
• C. Increase the temperature in the combustion chamber
• D. Cool the gas entering the compressor

Answer: (B)

The regenerator recovers heat from the hot exhaust and uses it to preheat the air that has just been compressed. By raising the temperature of the incoming air before combustion, you need less fuel to reach the turbine inlet temperature, so the overall thermal efficiency of the cycle improves. It doesn’t push exhaust back through the compressor, it doesn’t increase the turbine’s own mechanical efficiency, and it doesn’t cool the gas entering the compressor; it works by transferring exhaust heat to the compressed air to reduce fuel consumption.