An ecological optimization criterion for a class of irreversible absorption heat transformers

A new model for a class of irreversible absorption heat transformers is presented, in which not only the irreversibilities of heat conduction but also the irreversibilities resulting from the internal working fluid dissipation are considered. An ecological optimization criterion is proposed for the best mode of operation of such a class of heat transformers. It consists of maximizing a function representing the best compromise between the rate of heat pumping and the loss rate of heat pumping. It is shown that the model adopted here may be treated as a combined cycle of an irreversible Carnot heat engine and a reversible Carnot heat pump, and by using the combined cycle method, many problems of the heat transformer can be solved simply and conveniently. The ecological optimal performance of the heat transformer is investigated by using such a method and the significance of the ecological optimization criterion is discussed. The results obtained here are of importance in the optimal design and reasonable use of the energy of heat transformers.