Segmental baffles are used in the conventional shell and tube heat exchanger (STHX). Helical baffles can be used in place of segmental baffles, which increase the heat transfer efficiency and lessen the pressure losses. To avoid flow induced vibrations and eliminate stagnant recirculation zones, a new type of clamping anti-vibration baffle is proposed. Three dimensional CFD simulations, have been performed on ANSYS FLUENT to study and compare the pressure drop and heat transfer coefficient between the newly designed clamping anti-vibration baffles with square twisted tubes, helical baffles with cylindrical tubes and conventional segmental baffle with cylindrical tubes. For the numerical comparison whole heat exchangers are modeled, the numerical model shows the thermo-hydraulic performance with good accuracy by comparing it with Kern and Esso methods for single segmental baffles. It is then used to compare the performance of the same heat exchanger with clamping anti-vibration baffles with square twisted tubes (CBSTT-STHX) and helical baffles with cylindrical tubes (HBCT-STHX). CBSTT-STHX has a higher heat transfer coefficient than segmental baffles with cylindrical tubes (SGCT-STHX) and less pressure drop than both helical baffle with cylindrical tube (HBCT-STHX) and segmental baffle with cylindrical tubes (SGCT-STHX), while its comprehensive performance is higher than SGCT-STHX and slightly less than HBCT-STHX. |
