RP-922 -- EHD Enhanced Condensate Heat Transfer of Alternative Refrigerants/Refrigerant Mixtures for HVAC Applications PDF

An experimental investigation was performed to demonstrate the feasibility of the electrohydrodynamics (EHD) technique for the enhancement of in-tube and external condensation of refrigerants and refrigerant blends. This effort was intended to generate a wide range of experimental data. The experimental data were used to formulate semiempirical correlations that could predict the condensation heat transfer performance of the refrigerants inside the tubes for the given set of refrigerants and tube types. This is the first step in formulating a generalized correlation which requires a wide range of parametric studies. The in-tube condensation experiments were performed for a smooth tube and a corrugated tube with three different refrigerants, namely, single-component refrigerant R- 134a, a near-azeotropic three-component refrigerant R-404a, and a three-component zeotrope R-407c. The external condensation experiments were carried out for R-134a and R-404a for two different enhanced tubes. The tubes used in external condensation experiments were Turbo CII and GEWA-C2.