The purpose of a regenerator 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)

A regenerator uses heat from the turbine exhaust to preheat the compressed air before it enters the combustion chamber. This reuse of waste heat means the fuel doesn't have to supply as much energy to raise the combustor temperature to the turbine inlet temperature, so less fuel is needed and the overall thermal efficiency of the cycle improves. It’s a heat exchanger located in the exhaust path that recovers energy rather than sending exhaust back through the compressor or cooling the air entering the compressor.