Nucleate pool-boiling of R-114 refrigerant and oil mixtures from water-heated enhanced surfaces.
McManus, Stephen M.
MetadataShow full item record
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 m/s. For these 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.
Approved for public release; distribution is unlimited
Showing items related by title, author, creator and subject.
Phillips, Jonathan (United States of America as represented by the Secretary of the Navy, Washington, DC (US), 2017-07-18);A capacitor has two electrodes, one having a porous, electrically non-conductive material formed on a surface of the electrode, for example, by subjecting the conductive material of the first electrode to an anodization ...
Jenkins, Natalie-Rose L. (Monterey, California: Naval Postgraduate School, 2015-09);The results of this study establish that powder-based super dielectric materials (SDM) are a large family of porous electrically insulating materials filled to the point of incipient wetness (paste consistency) with liquids ...
Young, Jeremiah J. (Monterey, California. Naval Postgraduate School, 2010-09);Friction Stir Processing (FSP) is an emerging technology that allows for the processing of regions near the surface of a material in order to improve upon the existing mechanical properties. Aluminum alloy samples were ...