Abstract: An irreversible four-heat-temperature absorption heat-transformer cycle model is established by taking account of the heat leakage, internal irreversibilities and heat resistances between working substance and heat reservoirs with heat transfer law of . The general relation between the heating load and COP (coefficient of performance) with is deduced. The fundamental optimal relation, the maximum heating load, the maximum COP, the optimal temperatures of working substance, as well as the optimal heat transfer surface areas distribution with linear phenomenological heat transfer law are derived. Moreover, effects of heat transfer law, heat leak and internal irreversibilities on the performance of absorption heat-transformers are analyzed, and the performance comparison is performed for the distribution of the total heat transfer surface area is optimized or not by numerical example.

Key words: Absorption heat-transformer, Heat leakage, Heat transfer law, Internal irreversibilities, Optimal performance