Augmentation of condensation on horizontal finned tubes by attaching a drainage strip. Effects of material and height of the drainage strip.

Condensation of R-134a on horizontal integral-fin titanium tubes

“…The surface tension brings about the retention of the condensate between fins. Honda et al [16] derived Eq. 11 to obtain the halfangle of the condensate retention for trapezoidal low fins.…”

Condensation Performance of Some Commercial Integral Fin Tubes With Steam and Cfc113

“…This is due partly to the entrance effects in the short tubes used, and partly to slight undulations on the inside surface due to the firming process. Also shown in Tables 2 and 3, for the K-and N-type tubes (i.e., those with trapezoidal-cross-section fins), is the "flooding angle" <Pt' i.e, the angle, measured from the top of the tube, at which the interfin space becomes full of retained condensate, calculated from the equation of Honda et al [11] as follows: effective area enhancement ratios are also lisled in Tables 2 and 3. It is interesting to note that in the case of steam there is no clear relation between effective area and enhancement ratio, while for CFC1l3 the enhancement ratio generally increases with increase in effective area.…”

Experimental Study on Condensation Heat Transfer and Flow Modes of R245fa on Enhanced Surface Tubes

“…However, the°ooding angle decreased with decreasing¯n spacing at the base of the¯n tip. 6 As a result, the active condensation heat transfer area decreased with decreasing the¯n pitch. ∆T, ∆W decrease The Nusselt number of low-¯nned tubes strongly a®ects the enlargement factor of the heat transfer area with increasing¯n height compared to the¯n pitch.…”