A three-dimensional model is applied in this paper to simulate the falling film flow on shell-side of the spiral wound heat exchangers (SWHEs), the flow behavior is simulated with winding angle varied from 0Â° to 20Â°. The falling film process of the spiral tube is analyzed and film thickness is measured in axial and circumferential direction. Meanwhile the dimensionless parameter of maldistribution is defined to evaluate the thickness distribution deviating from the ideal condition and the maldistribution is calculated with the simulated results. Results show that the winding angle can influence the flow behavior. The maximum film thickness decreases with the increase of the winding angle at the same circumferential angle. The ascending flow region reduces and the declining flow region enlarges with the winding angle increasing. The maldistribution declines with the winding angle increasing.
Keywords spiral wound heat exchangers, film thickness, maldistribution, numerical simulation