Optimization of a Brayton cycle engine in contact with fluid thermal capacities.

Finite time thermodynamics studies have recently been devoted to all kind of cycles. Some works have been done on Brayton engine cycles. The proposed model is a synthesis of the preceding ones; this model completes the preceding papers, particularly regarding the two following aspects: 1) it takes into account the thermal losses occurring between heat source and sink, that are finite time reservoirs; 2) it influences the two limiting conditions for fluids at source and sink (four cases). The study is performed with partial and total regeneration, and without regeneration of heat. Influence of global internal irreversibility of the engine is also included in the sensitivity analysis of the proposed model. Results are presented in a nondimensional form useful for design project. Limiting cases are enlightened by the proposed method, and allow us to discuss the whole set of previously obtained results.