Experimental investigation of the condensation mechanisms in the shell side of spiral wound heat exchangers

摘要

An experimental investigation of the water vapor condensation mechanisms occurring in the shell side of spiral wound heat exchangers was conducted. Eight different test sections with varying structures were fabricated, each with an observation window, to investigate the effects of the geometric parameters on the condensation process. The experimental results indicated that there is a minimum condensation heat transfer coefficient for the top tube as the inclination of tube increases because of the changes in the film thickness. A comparison of the heat transfer coefficient between each individual tube and the entire test section was conducted and indicated that the heat transfer in the lower tubes dominate the overall heat transfer of the test section. While increases in the tube pitch changes the velocity field in the shell side, it also results in a decrease in the shell-side condensation heat transfer coefficient and the overall heat transfer of the test section.