Influence of Irreversible Heat Transfer on Heat Engine-Driven Heat Pump Performance

The coupling of a heat engine with a conventional compression heat pump is considered. Classical thermodynamics would provide, as upper performance limit of such a system, the one achieved in the case in which Prime Mover and Heat Pump both operate according to a Carnot cycle. Finite-time thermodynamics, utilizing heat transfer theory, allows to develop irreversible plant models that provide more realistic information about actual systems. In this paper, attention is paid to the search of optimum heating performances of a heat engine-driven heat pump whose waste heat engine is used for heating purposes: for such a system it will be shown that the maximum desired output is achieved in conditions different from those that we would observe in the case of simple mechanical coupling between prime mover and compression heat pump, with no use of heat recovery system.