Brayton Cycle

A thermodynamic cycle (also variously called the Joule or complete expansion diesel cycle) consisting of two constant-pressure (isobaric) processes interspersed with two reversible adiabatic (isentropic) processes.

 

Process:

• 1-2 : Isentropic Compression
• 2-3 : Constant Pressure heating
• 3-4 : Isentropic Expansion
• 4-1 : Constant Pressure cooling

Heat Supplied = mC_p(T₃-T₂)

Heat Rejected = mC_p(T₄-T₁)

Efficiency:

Note:

1. The efficiency of the brayton cycle lower than Carnot efficiency. The reason is that all the heat is not taken in at highest temperature and rejected at the lowest temperature.
2. The cycle is not thermodynamically reversible, because there is no generator to provide a constant temperature during heating and cooling at constant pressure.