A computer program has been developed by which an absorption heat transformer can be simulated and its parts can be technically and/or economically optimised. By means of this program, three binary and three ternary water-based electrolytes have been evaluated and compared with H₂O/lithium bromide as possible working fluids in absorption heat transformers. The two main parameters in such comparisons are the coefficient of performance (COP) and the theoretical maximum temperature lift. It is shown in this work that the COP and the temperature lift can be evaluated together in the form of heat output per unit heat transfer area. With these criteria and the difference in heat transfer coefficients taken into account, it is shown that the H₂O/KOH mixture should provide performance as good as, or better than H₂O/lithium bromide in many cases. The other mixtures were found to be inferior to H₂O/lithium bromide, with the possible exception of the ternary mixture H2O/LiBr-LiCl.

KEYWORDS: fluids, absorption heat pumps, computer programs, optimisation, maximum, water, lithium bromide, comparing, coefficient of performance, electrolytes, temperature lift, calculating, heat flow, heat transfer coefficient.