Performance Study And Structural Optimization On Heat Exchanger With Helical Baffles

A research of numerical simulation on heat exchanger with bow-shaped baffles, heat exchanger with continuous helical baffles, traditional heat exchanger with 1/4 helical baffles and new type heat exchanger with 1/4 helical baffles by using Fluent software has been done in this paper. This paper do a research on the internal flow field, heat transfer performance, resistant performance and comprehensive performance in the shell side systematically. With the mesh-independent of heat exchanger with bow-shaped baffles verified, the mesh size are defined as 1.7mm. For not only leakage problem in the center of shell side and between baffles, but also high pressure drop in the import and export of shell side of the heat exchanger with 1/4 helical baffles, some measures that widen the baffles and tilt the import and export of the shell tube have been proposed in this paper.According to the simulation results, it comes to following conclusions:the best helix angle of heat exchanger with helical baffles ranges from 25°to 36°. When it comes to the comprehensive performance, heat exchanger with continuous helical baffles is the best, the value is 1.018～1.052 times better than traditional heat exchanger with 1/4 helical baffles, the comprehensive performance of new type heat exchanger with 1/4 helical baffles is about 1.05 times better than traditional heat exchanger with 1/4 helical baffles, but the value of heat exchanger with bow-shaped baffles is 0.534～0.573 times than traditional heat exchanger with 1/4 helical baffles. Meanwhile, the relationships between Nusselt number(Nu) and resistant coefficient(f) with Reynolds number(Re) have been established in this paper. In the end, an experimental study was done on new type heat exchanger with 1/4 helical baffles after been designed and manufactured, then it comes to the conclusions that the heat transfer coefficient at both of the tube and the pressure drop on the shell side deviate-7.62%～2.35% and about 15% between experimental values and simulation values, validating the correctness of the numerical simulation in this paper further.