Parametric optimization of overlapped helical baffled heat exchangers by Taguchi method

• Overlapped helical baffled heat exchangers were firstly optimized by Taguchi method.
• Parametric influence was evaluated by Intuitive and statistical analysis methods.
• It is shown that overlap size is the more significant parameter than the others.
• The optimal parametric combination has better comprehensive performance (JF factor).

Taguchi method was firstly applied to investigate the influence of five geometric parameters on the comprehensive performance of overlapped helical baffled heat exchangers. These five geometric parameters are helix angle, overlap size, diameter of tube, central distance of tube and tube layout. Fifteen cases with different combination of geometric parameters mentioned above are modeled and analyzed with respect to the heat transfer and flow friction characteristics. Results show that the effect of overlap size on comprehensive performance is most significant among the five geometric parameters. In addition, the two analysis method (i.e. intuitive analysis and statistical analysis) are also conducted that the influence of five parameters is not clearly different and thus all the five geometric parameters should be taken into consideration in optimization design. Based on the analysis, an optimal parametric combination is obtained, which is validated to have better comprehensive performance (JF factor) than the fifteen models used in testing. The JF factor of the optimal combination is 11.81%–15.57% higher than the model with the relatively better comprehensive performance among fifteen cases.