Analysis On Dynamic Characteristic And Flow Induced Vibration Of Heat Exchanger Tube Bundles

With the industrial development and manufacture-scale expanding, the shell and tube heat exchanger tends to large-scale, then, the span of non-supported tube bundle increasing and the rigidity of heat exchanger decreasing, and for the improving heat exchange efficiency, the shellside velocity getting fast, as a result, the phenomenon of breakage of heat exchanger caused by flow-induced vibration is increasing. It was reported that lots of such breakages have appeared frequently in some factories both at home and abroad with fabulous damage degree. Therefore, study on flow-induced vibration in heat exchanger has become an important topic.Up to now, for the reason of immature computational method and the complexity of flow-induced vibration in heat exchanger, although scientists research on its mechanism, there are still many faultiness and indistinctness in this field. In the paper, the dynamic characteristic of tube bundles of heat exchanger, the mechanism of flow-induced vibration (vortex shedding, fluid elastic excitation), vibration control of tube bundles and the computational method of partial difference equation will be analyzed. It is useful discussion to ensure equipment's operation and investment saving. The innovative ideas and the main work in this paper are as follows:1. In the thesis, the dynamic characteristic of heat exchanger tube bundles is comprehensively analyzed by the way of theoretic analysis, numerical simulation and experiment. The analysis includes the elasticity of supporting component of heat exchanger, temperature prestressing, the fluid velocity inside tube, the interaction relation between fluid inside and outside tube and heat exchanger tube bundles, the effect of dynamic characteristic of heat exchanger tube bundles caused by the gap between tube and baffle-board. The analysis establishes the fundament to exactly estimate fluid-induced vibration.According to the structure character of tubular heat exchanger, the equipment is analyzed and divided by finite element method, the shell body, tube sheet, baffle-board are simulated as space shell element, and the tube is simulated as space beam element. Fine and routine simple finite element models are built. Dynamic characteristic is calculated with the...