Experimental study of the effects of key geometry parameters on shell-side vapor condensation of spiral-wound heat exchangers

Abstract

The results of an experimental study of the shell-side condensation characteristics of the spiral wound heat exchanger (SWHE) are presented in this paper. Ten testing SWHEs with different structures were manufactured to investigate the effects of key geometrical parameters on the shell-side vapor condensation characteristics. The overall heat transfer performance of the SWHE reflected in the experiment was also discussed. The experimental data reveal that the geometrical parameters have obvious influences on heat transfer performance. Large tube pitch and layer pitch have positive effects on the heat transfer because of minimized surface tension effects between the shell-side tubes. Based on the experimental conditions, the heat transfer coefficient increases by an average of 43.86% when the tube pitch increases from 4 mm to 10 mm, and the average increment of the heat transfer coefficient exceeds 45% when the layer pitch increases from 0 mm to 4 mm. With the increase of the winding angle from 8° to 16°, the heat transfer coefficient hits a minimum at 14° when the tube-side mass flow rate is over 12 m3·h−1 and the vapor flow rate is 280 kg·h−1. The effects of working conditions on the heat transfer are considered as well. When the tube-side mass flow rate increases, there is a maximum in the range of 10 m3·h−1 to 14 m3·h−1 for the overall heat transfer coefficient. The results of the experiment could be a guideline for designing and manufacturing of SWHE.