Accession Number : ADA187095

Title :   Pool Boiling of R-114/Oil Mixtures from Single Tubes and Tube Bundles.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Murphy, Thomas J

PDF Url : ADA187095

Report Date : Sep 1987

Pagination or Media Count : 144

Abstract : An apparatus was designed, fabricated and operated for the testing of horizontal tube bundles for boiling of R-114 with various concentrations of oil. Preliminary data were taken on the top tube in the bundle, with and without the other tubes in operation. Results showed up to a 37 percent increase in the boiling heat-transfer coefficient as a result of the favorable bundle effect. In a separate single-tube apparatus, three enhanced tubes were tested at a saturation temperature of 2.2 C with oil mass concentrations of 0, 1, 2, 3, 6 and 10 percent. The tubes were: 1) a finned tube with 1024 fins per meter, 2) a finned tube with 1575 fins per meter and 3) a Turbo-B tube. These tubes resulted in enhancement ratios in pure refrigerant of 2.8, 3.8 and 5.2, respectively, at a practical heat flux of 30 kW/sq. meter. With 3 percent oil, these ratios were decreased to 2.6, 3.5 and 5, while with 10 percent oil, these ratios were further reduced to 2.6, 3.2 and 4.7, respectively. Based on these results, the use of Turbo-B tubes is expected to result in significant savings in weight and size of evaporators over the finned tubes presently in use on board some naval vessels. Keywords: Nucleate pool boiling; Oil contamination.

Descriptors :   *BOILING, *EVAPORATORS, *TUBES, *REFRIGERANTS, BUNDLES, CONTAMINATION, FINS, HEAT FLUX, HORIZONTAL ORIENTATION, NAVAL VESSELS, OILS, OPTIMIZATION, RATIOS, SATURATION, TEMPERATURE, FRESH WATER, HEAT TRANSFER COEFFICIENTS, HEAT EXCHANGERS, WEIGHT REDUCTION, THERMAL RESISTANCE, MODEL TESTS, THESES

Subject Categories : Air Condition, Heating, Lighting & Ventilating

Distribution Statement : APPROVED FOR PUBLIC RELEASE