Experimental study on shell side heat transfer characteristics of two-phase propane flow condensation for vertical helically baffled shell-and-tube exchanger

Abstract

Vertical helically baffled shell-and-tube heat exchangers (HBHXs) occupy smaller ground areas compared to horizontal HBHXs and have been used as propane condensers in liquefied natural gas (LNG) plants. The heat transfer characteristics of propane in the shell side of vertical HBHX were investigated in the present study. The flow patterns and heat transfer coefficients in the shell side of a vertical HBHX test sample were obtained, and the results were compared with the existing data of the horizontal HBHX. The experimental conditions cover mass flux of 20–40 kg m−2 s−1, heat flux of 3.0∼7.0 kW m−1, and vapor quality from 0.2 to superheated. It is found that the variation trend of propane heat transfer coefficient with the increase of vapor quality in the vertical HBHX shell side is similar to that of the horizontal one. However, opposite to the horizontal HBHX, the heat transfer coefficient increases with the rise of heat flux for two-phase propane in the vertical HBHX shell side, probably arising from the influence of convection heat transfer in the liquid film. The heat transfer coefficient of two-phase propane in the vertical HBHX is 15–55% lower than that in the horizontal one, due to the thicker liquid film on tubes in the vertical HBHX. A correlation was developed to predict the heat transfer coefficient, and it agrees with 93% of experimental data within a deviation of ±20%.