Optimal performance of an absorption refrigerator based on maximum ECOP

• We optimize the four-heat-source refrigerator performances based on ECOP criterion.
• We determine analytically the optimum parameters at maximum ECOP conditions.
• Internal temperatures, COP, specific cooling rate and entropy production rate.
• COPmax and ECOPmax occur for the same operating conditions.

A general cycle model including several major irreversibilities existing usually in real absorption refrigeration systems is established and used to investigate the new thermo-ecological optimal performance of a four-heat-source refrigerator affected by the irreversibilities of finite-rate heat transfer between the working fluid and the external heat reservoirs, heat leak losses of the cooled space, and internal dissipation of the working fluid. The ecological coefficient of performance (ECOP) of the cycle system is used as objective functions for optimization. The ECOP objective function is defined as the ratio of the cooling load to the loss rate of availability (or entropy generation rate). The maximum of the new thermo-ecological performance criterion and the corresponding optimal conditions have been derived analytically. The effects of irreversibility parameters on the general and optimal performances are discussed detailed. The practical operating region of the four-heat-source refrigerator is discussed. The obtained results may provide a general theoretical tool for the ecological design of four-heat-source absorption refrigerators.