Performance optimisation for two classes of combined regenerative Brayton and inverse Brayton cycles

This paper proposes a new cyclic model of combined regenerative Brayton and inverse Brayton cycles. The new combined regenerative Brayton and inverse Brayton cycles recover heat energy after the working fluid leaves the turbine of the inverse Brayton cycle while the original combined regenerative Brayton and inverse Brayton cycles recover heat energy before the working fluid enters the turbine of the inverse Brayton cycle. Performance analysis and optimisation of the two classes combined cycles are carried out. Furthermore, the effect of the regenerator on the performance of the two combined cycles is analysed. It is found that the new combined cycle can obtain higher thermal efficiency and larger specific work than those of the original combined cycle at low compressor pressure ratio of the top cycle, and the regenerator can improve the performance of both the combined cycles. By theoretical analysis of this paper, it reveals that the new combined cycle will be well applied in the prospect, and the original combined cycle will be suited to low power output equipments. This paper aims at enriching the gas turbine theory and providing a possible way to save energy.