Abstract :
In this paper, fluid flow and heat transfer in a laboratory (i.e., small size) shell-and-tube heat exchanger are analyzed with computational fluid dynamic software. In this type of shell-and-tube heat exchanger, baffles with different angles of rotation (0° [horizontal segmental baffle], 15° [from horizontal], 30°, 45°, 60°, 75°, and 90° [vertical segmental baffle]) are used. The effect of baffle orientation on shell-and-tube heat exchanger performance is investigated. The flow domain is meshed by three-dimensional tetrahedral elements. The obtained result has a good agreement with the analytical method (i.e., the Bell-Delaware method) and experimental data in the literature. By comparing the pressure drop, heat transfer, and heat transfer versus pressure drop (Q/ P) at same flow rate, the shell-and-tube heat exchanger with 90° orientation performs better than other baffle orientation angles. The 90° orientation decreases pressure drop by 26%, 4.1%, 17.6%, 24.42%, and 14% more than the 15°, 30°, 45°, 60°, 75°, and 0° angles of orientation, respectively. This shows the 90° angle has better performance than other angles of baffle orientation. By reducing the pressure drop while maintaining the heat transfer rate, using this baffle orientation best reduces operating cost.
