Keywords: finite-time thermodynamics, heat engines, irreversibility parameter, irreversible cogeneration, thermal exergy optimisation, cogeneration power plant, optimal design, exergy analysis
Thermal exergy optimisation for an irreversible cogeneration power plant
The optimal design model, based on exergy analysis, of an irreversible cogeneration cycle has been presented using finite-time thermodynamics. The external irreversibility is due to the thermal resistance between the system and the heat reservoirs while the internal irreversibility is due to the non-isentropic compression and expansion process within the system. The internal irreversibility of the irreversible cogeneration cycle is characterised by a single parameter representing the ratio of relevant entropy differences. The presence of this irreversibility parameter shows that a cogeneration power plant with internal irreversibilities delivers less exergy output and has a lower efficiency than those of the reversible and endoreversible cycles. The model presented here is of more use when compared to those obtained by earlier researchers.