Abstract
In this work, a shell and tube heat exchanger with inclined trefoil-hole baffles (STHX-IT) is proposed, and the numerical simulation is conducted to investigate the flow and heat transfer characteristics. A shell and tube heat exchanger with segmental baffles (STHX-SG) is also studied for the performance comparison. The results show that the heat transfer coefficient and pressure drop of the STHX-IT is averagely lower by 23.89% and 44.19% than those of the STHX-SG, but the heat transfer coefficient per pressure drop is higher by 36.38% on average. Further, the parametric studies of the inclination angle θ, trefoil-hole number n, and baffle cut δ are carried out for the STHX-IT. According to the numerical results, n and δ have more notable influence on shell side performance than θ. In detail, the heat transfer coefficient and pressure drop decrease slightly with θ increasing, and the overall performance is approximately equal; both the heat transfer coefficient and pressure drop decrease with the respective rising of n and δ, but the comprehensive performance shows a growing trend. Considering the synthetic effects of structural parameters, the multi-objective structure optimization using the genetic algorithm combined with the artificial neural networks is fulfilled. As a result, the Pareto front is obtained to characterize the behaviors of the maximum heat transfer rate and minimum pressure drop. The STHX-IT with the θ = 5.38°, n = 6, and δ = 43% is decided as the optimal solution by the TOPSIS method, whose Q/Δp is 2.34 times as much as that of the original STHX-SG.
Highlights
As one of the most widely utilized devices for heat transfer in industry, heat exchangers play a significant role in many fields, including chemical engineering, petroleum processing, power systems, and waste heat recovery
The results indicated that the trefoil-hole baffles augment the heat transfer with large pressure loss, and using helical baffles can achieve the highest comprehensive performance
As for the shell and tube heat exchangers (STHXs)-IT, it is observed that the inclined trefoil-hole oblique flow along the flow direction, and some fluid flows through the trefoil-holes instead of the baffles provide the oblique flow along the flow direction, and some fluid flows through the trefoilmainstream between the baffles
Summary
As one of the most widely utilized devices for heat transfer in industry, heat exchangers play a significant role in many fields, including chemical engineering, petroleum processing, power systems, and waste heat recovery. The shell and tube heat exchangers (STHXs) occupy more than 35% to. 40% among various types owing to its simple manufacturing, high pressure-resistant ability, and low cost [1,2]. Baffles within the shell side are employed to support tubes, prevent vibration, guide flow direction, and increase fluid velocity. The structures of baffles exert an important influence on the thermal-hydraulic performance of the STHXs. The conventional shell and tube heat exchanger with segmental baffles (STHX-SG) provides a zigzag flow in the shell side, which have many advantages, such as high heat transfer performance, versatile adaptability, and simple maintenance. There still exist some drawbacks with the STHX-SG, for instance, high pressure loss, large flow dead zones, easy fouling, and flow-induced vibration. Numerous studies are focused on improving the comprehensive performance of the STHXs by overcoming the weaknesses above
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
