Brayton cycle

The Brayton cycle is a thermodynamic cycle that can be used for power generation. It uses a gas a working medium. An airplane turbo engine is an example of an open Brayton cycle A nuclear reactor power plant using helium cooling is an example of a closed Brayton cycle.

The ideal equation for a Brayton cycle is efficiency(ef) = 1-Tc/Th. An actual Brayton engine has a number of inefficiencies and non-reversible, so the actual efficiency is significantly lower. So for a high efficiency Brayton cycle, Th needs to be significantly higher than Tc.

For example, with an efficiency of 40% Tc/Th is 0,6. If Tc is 500K, then Th is 830K. For the same example at 60% efficiency, Tc/Th=0,4, and for a TC of 500K Th is 1250K.

If applied to a closed cycle used on Mars, Tc is the radiator temperature, and Th would be the temperature of the reactor core.