Research Of Curved Baffle Heat Exchanger

As having reliable structure, mature technique and wide application, shell-and-tube heat exchanger is the major form of heat exchange equipment and widely used in chemical, oil refining, power, food, medicine, aerospace and many other industries. Research of shell-and-tube heat exchangers mainly aims at enhancing heat transfer and lowering the pressure drop. For the shell side, concentrates are often put on the study of the tube bundle supporters or baffles.In this thesis, a new type of shell-and-tube heat exchanger-curved baffle heat exchanger which was proposed by Beijing University of Chemical Technology was taken into consideration. Heat transfer and flow resistance of fluid in the shell side were studied numerically and experimentally.For the experiments, tested heat exchangers with curved baffles were designed and the traditional heat exchangers with plane baffles were also made for comparison. Tube bundles in these heat exchangers are detachable so as to consider the effects of baffle structures and distance between them. By changing volumetric flow in the tube or shell side and the inlet temperature of tube side fluid, a large amount of experimental data about the pressure drop and heat transfer coefficient in the shell side were obtained related to different baffle structures.For the simulation, numerical analysis models for the curved baffle heat exchanger and plane baffle heat exchanger were established using the software Fluent. Pressure drop and heat transfer coefficient in the shell side were calculated. Compared with the experiments, the error for the simulation of pressure drop is less than 10% and that for the heat transfer coefficient less than 15%.Based on the approved numerical calculation model, parametric analysis was performed and the effects of baffle structures and distance between them on the pressure drop and heat transfer coefficient in the shell side were simulated.With sufficient calculation data and referring to the correlations for the pressure drop and heat transfer coefficient in the shell side of a plane baffle heat exchanger, corresponding correlations for a curved baffle heat exchanger were regressed which will be helpful for the design and engineering application of this kind heat exchangers.