Optimal performance characteristics of a two-stage irreversible combined refrigeration system under maximum cooling load per unit total cost conditions

In this payer, we report a study on the thermoeconomical performance optimi zation of a two-stage irreversible combined refrigeration system affected b y the irreversibility of heat transfer across finite temperature difference s, the heat leak loss between the external heat reservoirs and the internal dissipation of the working fluids. The cooling load per unit total cost is taken as an objective function for the optimization, The maximum of the ob jective function and the corresponding optimal performance and design param eters have been derived analytically. The global and the optimal performanc e characteristics curves are presented in terms of technical and economical parameters. The effects of the major irreversibilities and the economical parameters on the general and optimal performances have been investigated. Some new results, which may play an important role in determining the econo mical design conditions of real two-stage refrigeration systems, are obtain ed. (C) 2000 Elsevier Science Ltd. All rights reserved.