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Calorimetric and Visual Measurements of R123 Pool Boiling on Four Enhanced Surfaces.


pdf icon Calorimetric and Visual Measurements of R123 Pool Boiling on Four Enhanced Surfaces. (3121 K)
Kedzierski, M. A.

NISTIR 5732; 59 p. November 1995.

Sponsor:

Department of Energy, Washington, DC

Available from:

National Technical Information Service
Order number: PB96-128129

Keywords:

building technology; electric resistance heating; enhanced heat transfer; fluid heating; GEWA-K(TM); GEWA-T(TM); high-flux(TM); porous surface; T-fin; trapezoidal-fin; R123; pool boiling; Turbo-BII(TM)

Abstract:

Pool boiling of R123 on four commercial enhanced surfaces was investigated both calorimetrically and visually. The four surfaces were: (1) Turbo-BII(TM) (2) High-Flux(TM) (3) GEWA-K(TM), and (4) GEWA-T(TM). The surfaces were either machined or soldered onto a flat thick oxygen-free high-conductivity 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 onset of nucleate boiling were also investigated. The boiling was visually recorded with 16 mm high speed film. Mechanistic descriptions of the boiling activity are given for each surface.