Brayton cycle

The Brayton cycle the basic thermal power cycle implemented in gas turbines. ASCEND provides support for modelling Brayton cycles with a range of models of increasing complexity.

The models are provided in the file models/johnpye/fprops/brayton_fprops.a4c. These models make use of the FPROPS fluid properties library to obtain high-accuracy thermodynamic property evaluation. Some earlier models using ideal air as the working fluid are available in the model file models/johnpye/brayton.a4c.

See also Combined-cycle gas turbine

Split Brayton Cycle

This cycle has been identified as highly efficient when the working gas is supercritical carbon dioxide (sCO2). The configuration is shown below.

Split Brayton cycle configuration (Figure: Rachel Hogan)

The model brayton_split_co2, contained in the file models/johnpye/fprops/brayton_split.a4c, implements this cycle. The T-s diagram of the cycle in our default configuration is shown below:

T-s diagram for the split Brayton cycle

Regenerative Brayton cycle

Regenerative Brayton cycle configuration (Figure: Rachel Hogan)

This cycle is implemented in the model brayton_regen, contained in the file models/johnpye/fprops/brayton_fprops.a4c. The T-s diagram of the cycle in our default configuration is shown below:

T-s diagram for the regenerative Brayton cycle

Regenerative Brayton cycle with reheat and intercooling

This cycle is an improvement on the simple regenerative Brayton cycle as it allows the compression and expansion to take place at closer to a uniform temperature, increasing the area inside T-s cycle loop. The model is shown here is brayton_regen_reheat_intercool_co2 from models/johnpye/fprops/brayton_fprops.a4c.

Configuration of the regenerative Brayton cycle with reheat and intercooling (Figure: Rachel Hogan)

T-s diagram for the regenerative Brayton cycle with reheat and intercooling

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