The Numerical Simulation Study On Heat Transfer And Stress Characteristics Of The Pre-stressed Heat Exchanger

The shell-and-tube heat exchanger is widely used because of its simple structure, maturedesign methods, rugged and reliable, large handling capacity, strong compatibility, safety andreliability. And the baffle rod heat exchanger is becoming widely used because of its simplestructure, high heat transfer efficiency and good resistance to fluid vibration performance. Theapplication of the traditional fixed tube plate heat exchanger is subject to considerablerestrictions by the influence of the thermal stress of the shell and tube.The pre-stressed technology can greatly reduce the thermal stress of fixed tube-sheetexchanger. Therefore, it has very important significance to study the flow, heat transfer andrelated strength properties of the prestressed heat exchanger. The main work was done in thisarticle include:1. For the problems of the previous studies, we get a more realistic model throughmodeling the E flow path and tube-side fluid at the basis of reasonable to simplify the actualstructure. In order to achieve the simulation of tube side fluid phase change heat transfersegment, we use the FLUENT multiphase flow model to solve the problem of tube side fluidmodeling and compile the phase change program with the UDF interface. And we get themore close to actual temperature field. Then the temperature field distortion is loaded into theANSYS model through Interpolation map.2. We prove that the method of the "segmentation modeling, segmentation meshing,segmentation simulating" by using the overall model and the segmentation model. We specifytheir own characteristics and limitations of the two simulation methods.3. We change the fluid temperature and flow rate of the tube side fluid when the otherprocess parameters remain the same, so as to explore the technology of pre-stressed and law.4. We study the temperature field of the different baffle element and analyze theinfluence of the different baffle element to the stress feature of the pre-stressed heatexchanger.The conclusions of the paper are as follow. By modeling the E flow path and tube-sidefluid, we get more in line with the actual flow and temperature field using FLUENTmultiphase flow model for phase change heat transfer analysis and obtain accurate thermalstress field. The limitations of the overall model is only applied to small model and difficultfor the detailed modeling of the large model. By studying the applicability and reliability ofthe segmentation model, we found that segmented simulation technology is no strict limit tothe scale of the heat exchanger. It can be used in the implementation of the accurate modeling of small heat exchanger and also large-scale heat exchanger for reasonable modeling. Theaccurate modeling method of the segmented simulation technology has laid a solid foundationfor the implementation for the simulation of large-scale heat exchanger model.