Effect of Inundation Upon the Condensation Heat Transfer Performance of R-134a: Part II—Results (RP-984)

Shell-side heat transfer coefficients were experimentally determined for three different types of tubes in a 25-tube bundle designed to simulate a single-pass heat exchanger. Smooth tubes, two-dimensional integral fin tubes, and three-dimensional enhanced-surface tubes were arranged in a three-column-by-ten-row staggered pattern with a horizontal and vertical pitch of 22.9 mm. Bundle average heat transfer coefficients and row-by-row heat transfer coefficients were measured as part of this study. Results showed the three-dimensional enhanced tube had the highest condensation heat transfer coefficient of any tube tested during the course of the study. Bundle average heat transfer coefficients for the three-dimensional tube showed a steady decline with increased heat flux and the row-by-row heat transfer coefficients showed an almost linear decrease with increased row number. The performance of the two-dimensional tube showed variations with heat flux but showed less sensitivity to inundation level. The experimental results for all tubes were compared with published correlations. Experimental results for the two-dimensional tube were predicted well by the correlations, but no suitable correlation was found for the three-dimensional tube so one was developed.