Working mixtures for industrial chemical heat pumps.

The thermodynamic properties that new working mixtures must exhibit in order to optimize the coefficient of performance (COP) and the temperature lift of the CHP, while keeping suitable pressure levels, are defined. Two simple CHP cycles (temperature and heat amplifier) are considered, although a brief reference is also made to advanced cycles. The actual values of the properties of a number of proposed working mixtures are presented, and their relative merits discussed. It is found that for industrial applications of the temperature amplifier cycle, the mixtures NaX zeolites water and sodium hydroxide water offer a relatively complete set of desirable thermodynamic properties. Organic mixtures, on the other hand, may be desirable for the implementation of the heat amplifier cycle.