Analysis and optimisation of an irreversible Brayton refrigeration cycle using exergy concept
An irreversible Brayton refrigeration cycle has been analysed by exergy method. The rate of total destroyed exergy is considered as an objective index. The purpose is to minimise the destroyed exergy. By the assumption of defining the recovery factor, the objective index is obtained. Due to the existence of irreversibilities, the compressor and expansion efficiencies are introduced. It is found that the minimum value of the rate of total destroyed exergy takes place when the isentropic temperature ratio is chosen as a reasonable minimum. The results can help in minimising of exergy destruction while one is operating the system.
Keywords: exergy destruction, irreversibilities, Brayton refrigeration cycle