Heat Transfer Evaluation of HFC-236fa in Condensation and Evaporation
Final rept. Sep 95-May 96
IOWA STATE UNIV AMES DEPT OF MECHANICAL ENGINEERING
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The report gives results of an evaluation of the shell-side heat transfer performance of hydrofluorocarbon HFC-236fa, which is considered to be a potential substitute for chlorofluorocarbon CFC-114 in Navy shipboard chillers, for both conventional finned 1024- and 1575-fpm fins-per-meter tubes and high performance enhanced Turbo-CII, -B, and -BII tubes. Condensation of oil-free HFC-236fa was conducted on 1024- and 1575-fpm, and Turbo-CII tubes. Pool boiling on four tube types 1024- and 1575-fpm, and Turbo-B and -BII was tested not only for pure HFC-236fa but also for HFC-236fa mixed with 1 and 3 lubricant by weight. The polyolester lubricant used has a viscosity of 340 SSU at 37.8 deg C 100 deg F and the trade name of Castrol Icematic SW-68. The above tubes, which have nominal outside diameters of 19.1 mm 34-in., were evaluated at a saturation temperature of 40 deg C for condensation and 2 deg C for pool boiling over the heat flux range of 15 to 40 kWsq m. Heat transfer was improved for HFC-236fa by using the high performance enhanced tubes. Specifically, the Turbo-CII tube performed better than the two conventional finned tubes in the condensation testing, while the performance of the Turbo-B and -BII tubes was superior to the two conventional finned tubes in the pool boiling testing.
- Organic Chemistry
- Air Pollution and Control