Several advanced cycles for the working pair H₂O/LiBr, which essentially combine the advantages of an absorption heat pump with those of a heat. transformer, are presented. These cycles are particularly suited for providing process heat and simultaneously recovering reject heat from that process. The heat ratios and thus the energy savings are appreciably higher than those for the two basic cycles, whereas the investment costs per energy saving are expected to be reduced, thus yielding shorter payback times. These heat pump - transformers can be used as heat supply systems for distillation, evaporation, and drying processes, etc ., and thus complement or replace mechanical vapor recompression in the chemical, food and beverage, paper and pulp, or water desalination industries. With respect to primary energy consumption, these systems can compete with mechanical compressors.

Applying such a heat pump - transformer as a heat supply system to a multistage water desalination plant reduces the number of required stages from 16 to 3, with the remaining three stages all operating at close to atmospheric pressure. Similar statements hold for other multistage distillation processes.

Units: SI