Paper Title
Condensation Heat Transfer Characteristics of R-134a Inside Vertical Helically Coiled Tube-In-Shell Type Heat Exchanger

In this study, condensation heat transfer coefficients of R-134a inside a vertical helical coiled tube are experimentally investigated. The inner tubes comprise of one smooth straight tube, and one vertical helical coiled tube. The experimental measurements are carried out at saturation temperature of 35o, with mass flux of 115, 156 and 191 kg m-2s-1. The effect of mass flux, and vapor quality of R-134a on the heat transfer coefficients are examined. Comparisons between smooth straight tube, and vertical helical coiled tube are also discussed. The results show that the vertical helical coiled tube produces a higher heat transfer coefficient compared to smooth straight tube. Keywords - Condensation, Heat transfer coefficient, R-134a, vertical helical coiled tube.