Thermodynamic Analysis of Irreversible Reversed Brayton Cycle Heat Pump with Finite Capacity Finite Conductance Heat Reservoirs

In this research, the analytical expressions for various parameters of an irreversible heat pump working on the reversed Brayton cycle, considering the finite capacity of the heat reservoirs, is derived using finite time thermodynamics. The effect of pressure ratio of the condenser and the temperature ratio of the heat reservoirs on the heat load, power required, COP and ECOP is studied under different operating conditions. Moreover, the effect of different working fluids on these parameters is also analysed. When the assumption of infinite heat capacity of reservoirs is implemented in the expressions derived, the results obtained match with the previous researches based on this assumption. It was found that there exist critical values of pressure ratio at which the COP and ECOP achieve maximum values. This critical pressure ratio increases as the temperature ratio increases and decreases as the heat capacity ratio of the working fluid increases.