Effect of geometrical parameters on flow and heat transfer performances in multi-stream spiral-wound heat exchangers

The influences of the changes in geometrical factors, including the space bar thickness, the tube pitch in the first layer, the tube external diameter, the number of layers and the centre core diameter on flow and heat transfer performances in multi-stream spiral-wound heat exchangers are numerical investigated. The shell-side and tube-side Nusselt number and pressure drop per unit length increase with the increase of number of layers, centre core diameter, and tube external diameter, but decrease with the increase of space bar thickness and tube pitch in the first layer. Quantitatively estimation of the affecting performances of these five geometrical parameters is implemented by using the Taguchi method, and the result shows that the contribution rate of them are more than 5%. Thus, the multivariate correlations with the main geometrical parameters considered are developed for shell-side Nusselt number and friction coefficient. (C) 2015 Elsevier Ltd. All rights reserved.