Abstract
Effects of a surfactant on performance of absorbers have been investigated experimentally. Experiments were conducted on three types of absorber, that are horizontal bear tube type and vertical plate type absorbers for absorption refrigerator/chiller, air-cooled vertical tube type absorber for heat transformer, with changing surfactant's concentration. Surfactant (n-octanol) concentration was varied in the range of 0∿250ppm. Temperatures of solution, coolant (water or air) and heat transfer surface were measured minutely. Furthermore, in case of the absorption refrigerator, flow conditions of LiBr aqueous solution were continuously observed optically. Refrigerating capacities and heat transfer rate to air were determined from those measurement results. Results showed that absorber performances were significantly improved with increase of surfactant concentration. In case of the absorption refrigerator/chiller, absorber performances became about double than that case of no surfactant. On the contrary, absorber performance increased only 15% in case of the heat transformer. Also, it has been confirmed that those improvement were caused by the occurrence of Marangoni convection in the solution flow when the surfactant was added.
