Experimental and numerical investigation on shell-side performance of a double shell-pass rod baffle heat exchanger.

Highlights • Performance of DS-RBHX and SS-RBHX is compared experimentally. • DS-RBHX has better comprehensive performance than SS-RBHX. • Three guide shells are proposed and investigated numerically. • All guide shells play a positive role in heat transfer enhancement of outlet zone. • DS-RBHX-GS2 is the best one among the three. Abstract In this paper, the heat transfer and flow performance of a double shell-pass rod baffle heat exchanger (DS-RBHX) is investigated experimentally. Likewise, a single shell-pass rod baffle heat exchanger (SS-RBHX) is set as the control. Water serves as the working fluid both in the shell side and tube side. Experimental results indicate that the overall heat transfer coefficient of the DS-RBHX is higher than that of the SS-RBHX for all measurements. As the shell-side volume flow rate varies from 2.8 to 15.2 m3/h, the shell-side heat transfer coefficient and pressure drop of the DS-RBHX increase by 33.5–54.0% and 34.0–74.3%, respectively. From the perspective of the comprehensive performance, the shell-side heat transfer coefficient of the DS-RBHX is 14.4–24.3% higher than that of the SS-RBHX under the same shell-side pressure drop. Consequently, it is proved that the DS-RBHX has better comprehensive performance compared with the SS-RBHX. On the basis of experimental results, numerical studies are conducted to analyze the shell-side behaviors of the DS-RBHX further. According to numerical results, three kinds of guide shells, arranged at the end of the sleeve, are proposed to reduce the flow dead zone in the shell-side outlet zone. The behaviors of DS-RBHXs with the guide shell (DS-RBHX-GSs) are obtained numerically. The results show that all three guide shells improve the heat transfer performance of the shell-side outlet zone, particularly in the outer side. Moreover, the guide shell of the DS-RBHX-GS2 has more significant effects than the others. [ABSTRACT FROM AUTHOR]