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.
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
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 ...
Wu, Chun-Hsien (The United States of America, as represented by the Secretary of the Navy, Washington, DC (US), 2021-12-07);A substrate for 3D printing using a cold spray technique. The substrate of the present invention has a porous surface with the size of pores smaller than approximately 24.4 times the mean particle size of feedstock ...