Performance of reciprocating Brayton cycle with heat transfer, friction and variable specific heats of working fluid

SYNOPSIS The performance of an irreversible air-standard reciprocating simple Brayton cycle with heat transfer loss, friction-like term loss and variable specific heats of working fluid is analysed by using finite-time thermodynamics. The relationships between the power output and the compression ratio, between the thermal efficiency and the compression ratio, as well as the optimal relationship between the power output and the efficiency of the cycle are derived by detailed numerical examples. Moreover, the effects of variable specific heats of the working fluid and the friction-like term loss on the irreversible cycle performance are analysed. The results show that the effects of variable specific heats of the working fluid and friction-like term loss on the irreversible cycle performance are obvious, and they should be considered in practical cycle analysis. The results obtained in this paper may provide guidelines for the design of practical reciprocating Brayton engines.