How does a regenerator improve the efficiency of a stationary gas-turbine engine?

In a stationary gas-turbine engine, a regenerator improves efficiency by capturing heat from the turbine's hot exhaust gases and using it to preheat the air leaving the compressor before it enters the combustion chamber.12

By raising the temperature of the air prior to combustion, the regenerator reduces the amount of fuel required to reach the desired turbine-inlet temperature. This process effectively recovers energy that would otherwise be lost to the environment. While this significantly decreases fuel consumption, it requires the addition of a heat exchanger, which increases the engine's initial cost. Consequently, the use of a regenerator is typically considered economical only for units that operate almost continuously.13