Post dryout heat transfer to R-113 upward flow in a vertical tube

Abstract An analysis of heat transfer in the post dryout region of upflow in a uniformly heated tube was performed on the basis of the three path heat-transfer model, involving heat-transfer processes from wall to vapor, from vapor to liquid droplets and from wall to droplets in contact with the wall. Wall temperature distribution was predicted by solving a set of equations describing the variations of droplet diameter, actual quality, vapor temperature and droplet velocity along the tube downstream of the dryout point. The predicted wall temperature distributions show a good agreement with the experimental data for R-113 presented in the previous report. This result indicates that most of the heat from the heating wall is transferred to the vapor flow and droplets vaporize principally in the superheated vapor flow.

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