Theoretical study of volatility effects on the performance of H-typed fin in waste heat utilization

In this paper, a comprehensive transient three-dimensional model for heat transfer performance and flow resistance is applied to investigate the characteristics of fin-and-tube heat exchanger with H-typed fin. The overall and local dynamic response performance of Nu number and Eu number under volatile flow conditions are analyzed in details. The results indicate that under different time-averaged velocity, the tendency of the Nu number is basically the same within the same cycle time. For the Eu number, both the value and change tendency are very different from each other. Under different volatile amplitude, the tendency of Nu number shows obvious distortion near the minimum of Re number. Meanwhile, the Eu number also has been distinctly influenced by the volatile amplitude, especially at smaller Re number conditions. Simulations also carried out for different cycle times from normal to small, results indicate that all the values and tendencies of both Nu number and Eu number are varying within a small range and can be ignored within the range of this study. Correlations of Nu number and Eu number for each case of volatile flow conditions are presented.