Nucleate Pool-Boiling of R-114 Refrigerant and Oil Mixtures from Water-Heated Enhanced Surfaces.
NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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Heat transfer measurements were made for a single, water heated tube in a pool of R 114 to simulate operating conditions of a water chiller. Data were obtained for a smooth copper tube, and for two commercially available tubes a spirally roped copper nickel tube with a porous coating and a copper tube with a structured outer surface and a multiple start helical ridged inner surface. Measurements were made for refrigerant oil mixtures at oil concentrations from 0 to 6 mass percent with a boiling pool temperature of 13.8 C. Results for the two enhanced tubes with and without oil are compared to the smooth tube data. Enhancement factors for the overall heat transfer coefficient were 4.0 and 3.6 for the structured surface and porous coated tubes, respectively, in pure refrigerant and at a water velocity of 2 ms. For those same conditions the enhancement factors for the outside heat transfer coefficient were 14.6 and 6.4 for the porous coated and structured surface tubes, respectively. Keywords Nucleate Pool Boiling Water Heated Tubes Enhanced Surfaces Theses Computer Programs.
- Pumps, Filters, Pipes, Tubing, Fittings and Valves