Brayton Cycle How It Works

There are two primary variants of the Brayton cycle the open cycle and the closed cycle [El-Wakil, 1984]. In an open cycle system, the coolant is drawn in from the outside environment, heated, run through a turbine, and discharged back to the outside atmosphere. In a closed cycle, the gas is in a closed loop and used repeatedly. There are two variants of closed Brayton cycles direct and indirect. In the direct system, the heat source is directly coupled to the gas flow system while in an indirect system, the coolant passes through an intermediary heat exchanger. A block diagram of a direct closed Brayton cycle is shown below  

Brayton conversion systems have advantages and disadvantages. They are more efficient than most static power conversion systems (e g., thermoelectric or thermionic based systems), and they are more durable and simpler than the other dynamic power conversion systems. However, Brayton cycles do require higher temperatures to achieve the same efficiency as other dynamic power conversion systems. The energy density of the working fluid is low compared to the other dynamic power conversion systems. 

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