Keywords: entropy, efficiency, refrigeration plant, thermodynamic modelling, irreversible heat, optimisation
Thermodynamic modelling and optimisation of an irreversible heat driven refrigeration plant
Thermodynamic modelling and optimisation of a real heat driven refrigeration plant is performed on the basis of the two considerations that: (i) it can be assimilated to the couplage of a power plant and a work input refrigerator; and that: (ii) the irreversibility of each plant can be regarded as due to a bypass heat leak taking place in parallel with an otherwise irreversibility free compartment. We express, first, the thermodynamic imperfection of a refrigerator as the result of the contributions of its two coupled components. In a second approach, an equivalent model is proposed and the expression of the equivalent conductance is determined. Accounting for the finiteness of the total internal thermal resistance of the refrigerator, it is shown that it exists an optimal allocation of this resistance corresponding to a maximum second law efficiency.