Abstract
In a condenser the thickness of the liquid condensate film covering the cooled surface constitutes a resistance to the heat transfer. By establishing a non uniform electric field in the vicinity of the condensation surface the extraction of liquid from the surface can be realized. The liquid film thickness is reduced and as a result the condensation heat transfer coefficient is increased. A vertical single tube condenser (I m long) is used to investigate the electrohydrodynamically enhanced condensation heat transfer performance on the outside surface of enhanced tubes. R-1 13 is the working fluid. Korodense (3.81 cm O.D.) and Turbo CIII (1.905 cm O.D.) enhanced tubes were tested. Smooth tubes (3.81 cm and 1.905 cm O.D.) served as the basis for comparison. Condensation heat transfer coefficients and overall UA-values are presented as a function of the applied voltage for the optimum smooth tube electrode design. The results show, for a given heat load, the Turbo CII tube can increase the condensation heat transfer coefficient up to 5.5 times smooth tubes values by applying electric fields. Lower but considerable enhancements were also achieved for the Korodense tube. The necessary electric power input was found to be negligible representing less than 0.004 % of the exchanged heat.
Motte, Edouard (1994). Augmentation of condensation heat transfer with electrohydrodynamics on vertical enhanced tubes. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1994 -THESIS -M922.