Abstract
A general description is developed for a class of irreversible refrigerators operating between two heat reservoirs. This description is applied to refrigerators having thermal resistances between the working fluid of refrigerators and the heat reservoirs, heat leaks between the heat reservoirs, and internal dissipations of the working fluid in order to obtain the maximum performance coefficient and the performance coefficient versus cooling rate characteristics of such refrigerators. This description is also applied to optimizing the key performance parameters of such refrigerators. Some new performance bounds of refrigerators are determined.