OPTIMIZATION OF SPECIFIC RATE OF HEAT PUMPING IN COMBINED HEAT-PUMP CYCLES

The optimization problem of a combined heat pump cycle made of two end oreversible Carnot heat pump cycles in series without intermediate res ervoirs is investigated using finite-time thermodynamics. The fundamen tal relation between heating quantity and coefficient of performance ( COP) of the combined cycle is derived. Relations are also derived betw een the SRHP (specific rate of heat pumping), the average rate of heat pumping per unit of total heat-transfer surface area and the COP for reciprocating and stable flow models of combined cycles. The results o btained from this paper may be extended to an endoreversible, combined heat pump cycle formed by more than two endoreversible Carnot heat pu mp cycles. Published by Elsevier Science Ltd.