Experimental Investigation Of Heat Transfer Capability Of Falling Film Evaporation In The Vertical Tube With Spring Inserts

When water was used as the medium, the influence of the spring inserts in the vertical tube to the heat transfer capability of falling film evaporation was studied. In the experiment, the interposition distributor was used. Spring inserts of eight different parameters were adopted in the uniform wall temperature. The result indicated that the heat coefficient can be improved by ameliorating distribution status. At the same time, the influence of temperature, Reynolds number of film, and vacuum degree etc. to the heat transfer capability on the evaporation side was studied. No.2 and No.5 spring inserts were the best spring inserts for enhancing heat transfer and the heat coefficient can be improved nearly 20 percents in the experiment condition. The optimum spring insert parameter range was also obtained on the base of the experiment. The experimental formulas of the heat transfer coefficient on the evaporation side in the smooth tube and in the vertical tube with spring inserts were fitted by the experiment data. The error between the predicated heat transfer coefficient through these two formulas and the experiment value was basically under 10%.The numerical simulation was used by FLUENT6.0 in the paper. The result of numerical simulation indicated that it was linear relationship between the zero dimension heat transfer coefficient and the Reynolds number of film. The error between the numerical value and the experiment value was basically under 28%. The numerical simulation characterized the experimental law.