Surfactant additives have been known for some time to influence the boiling characteristics of water and water-salt solutions. An enhancement of boiling heat transfer coefficients can be obtained by a proper choice of additives. When the capacity of an absorption heat pump is limited by its generator capacity and the generator is of the boiling-pool type, it is possible to increase the machine capacity by means of surfactant addition. In this paper, the preliminary experiments leading to the selection of a surfactant for a lithium bromide-water absorption heat pump are described. Minimum foaming was the most important consideration in this selection process. The measured machine performance shows that the generator capacity may he increased by values ranging from 5% to 10% of the original capacity. The actual value depends on the operating conditions as given by solution concentration, flow rate, and temperatures.

Units: SI