Condensation of R-134a inside micro-fin helical coiled tube-in-shell type heat exchanger

摘要

In this study, condensation heat transfer coefficients and frictional pressure drops of R-134a inside a micro-fin helical coiled tube with the cooling water flowing inside the shell in opposite flow direction are experimentally investigated. The inner tubes comprise of one smooth straight tube and one micro-fin helical coiled tube, which are made of copper. The experimental measurements are carried out at mass fluxes of 75, 115, 156 and 191 kg m(-2) s(-1) and saturation temperatures of 35 and 45 degrees C. In addition, the experimental data of a micro-fin helical coiled tube have been plotted on the mass flux versus vapor quality flow map and Tailtel and Dukler flow map. The transitions between different flow regimes inside micro-fin helical coiled tube have also been discussed.