Calorimetric and Visual Measurements of R123 Pool Boiling on Four EnhancedSurfaces

摘要

Pool boiling of R-123 on four commercial enhanced surfaces was investigated bothcalorimetrically and visually. The four surfaces were: (1) Turbo-BIITM-LP, (2) High-FluxTM, (3) GEWA-KTM, and (4) GEWA-TTM. The surfaces were either machined or soldered onto a flat thick OFHC copper plate. This permitted 20 sheathed thermocouples to be embedded in the copper for accurate heat transfer measurements. The difference between electric resistance and fluid heating was investigated. The fluid heating condition results in heat fluxes that are as much as 32% greater than those obtained by electric resistance heating. Hysterisis effects near the results in heat fluxes that are as much as 32% greater than those obtained by electric resistance heating. Hysterisis effects near the onset of nucleate boiling were also investigated. The boiling was visually recorded with 16mm high speed film. Mechanistic descriptions of the boiling activity are given for each surface.