Enhanced Condensation of R-113 on a Small Bundle of Horizontal Tubes

摘要

Condensation of R-113 was studied using an evaporator condenser test platform.The condenser section contained four horizontal tubes (nominal outer diameter 15.9 mm) forming a vertical in line column with a pitch-to-diameter ratio of 2.25 and a condensing length of 1.2m. The condenser tubes could be operated either individually (ie. as a single tube apparatus) or as a small tube bundle. This allowed investigation of the effects of condensate inundation on different types of condenser tubes. Tubes tested were smooth copper tubes, copper/nickel KORODENSE roped tubes, KORODENSE tubes wrapped with wire, and copper/nickel finned tubes (26 fpi). The outside heat transfer coefficient was calculated by experimentally determining the overall heat transfer coefficient and then using a modified Wilson Plot procedure. Great care was taken to ensure the results were not vitiated by the presence of noncondensibles. Results obtained with the smooth copper tubes are in agreement with published data and verify satisfactory operation of the test platform. Furthermore, problems associated with the apparatus encountered by previous workers were successfully overcome. In comparison to the top smooth tubes, the copper nickel top KORODENSE tube yielded about a 22% increase.