Performance comparison of heat exchangers using sextant/trisection helical baffles and segmental ones

Publication date: Available online 31 July 2019Source: Chinese Journal of Chemical EngineeringAuthor(s): Chen Yaping, Tang Hongling, Wu Jiafeng, Gu Huaduo, Yang ShifanAbstractThe shell side flow fields of both sextant and trisection helical baffle heat exchangers are presented on meridian and multilayer hexagon slices. It verifies that the performance of sextant schemes is better than those of the other kinds of helical baffle heat exchangers. The main mechanisms are due to the restricted leakage flow in the minimized gaps with increased baffle number and by one row of tubes dampens the leakage flow in the circumferential overlapped area of the adjacent helical baffles. The performance features were simulated on two different angled sextant helical heat exchangers and each compared with two trisection ones of either identical helical pitch or identical incline angle. The results verified that the performances of helical heat exchangers are mainly determined by the helical pitch rather than the baffle incline angle. The average values of comprehensive index hoΔpo-1/3 of the trisection helical Schemes T-24.1° and T-29.7° are correspondingly 3.47% and 3.34% lower than those of the sextant ones X-20° and X-25° with identical helical pitches. The comparison results show that the average values of shell side h.t.c. ho and comprehensive index hoΔpo-1/3 of the optimal dual helix sextant scheme DX30° are respectively 7.22% and 23.56% higher than those of the segment scheme S100...

Source: Chinese Journal of Chemical Engineering - August 1, 2019 Category: Chemistry Source Type: research