Examination of the performance envelope of combined Rankine, Brayton and two parallel inverse Brayton cycles

Abstract

The study presented in this paper investigated the performance of a proposed system constructed from Brayton, two parallel inverse Brayton and Rankine cycles. It has been carried out by varying the Brayton cycle pressure ratio for different values of expansion pressures of the two inverse Brayton cycles using variable inlet pressures, above atmospheric. The results revealed that the best theoretical performance could be achieved when the system was simulated with a high value of expansion pressure of the second inverse Brayton cycle. Also, it was shown that, as a result of altering the expansion pressure of the second inverse Brayton cycle, the range of the upper cycle pressure ratio increased and the system attained a high thermal efficiency (54 per cent).