Research On The Falling And Breaking And Unstable Analysis Of Tube - Shell Heat Exchanger Tube Bundle And Its Prevention And Control

In this paper, basic theory of fluid elastic instability and the phenomena of Stray bullet on the heat exchanger tubes were studied on the basic theory of fluid mechanics.This paper studied the theory of "tube-in-channel modle" proposed by Yetisir and Weaver. On the basis of the "lateral bundle stray bullet instability and unsteady analytical model" proposed by Weaver and Yetisir and Li Ming’s "linear attenuation function" proposal, the author derived a new expression based on Unsteady "flow control" model and calculated it with complex-number method.The new expression avoided the Y-W model numerical integration difficulties, fixed some deficiencies of Li Ming’s model and got elastic instability explicit analytical solution of Flow heat exchanger tubes.ADINA software was used to establish a three-dimensional finite element model of heat exchanger tubes at a certain percentage. The analysis of stress-strain showed that stress of the tube increases when it reached critical velocity, and the Bundle displacement increased significantly as well. For security reason, fluid velocity must be strictly controlled. The analysis of arranged in the form of tubes with different stable region indicated that was not the biggest security impact factor for same bundle. When flow rate and other circumstances were exactly the same, arranged in the form of tubes has significant impact on safety of heat exchanger tube array. When other circumstances were exactly the same, arranged in the form of pipes influenced stability diagram greatly, and had a certain degree of influence.According to theoretical analysis and experimental results, this paper proposed some methods of preventing and controlling of fluid elastic instability of heat exchanger tubes, which were mainly about reflected in terms of flow rate control and piping materials.