Study On Fluid Elastic Instability And Coupled Vibration Of Concentric Tube Bundles

The intermediate heat exchanger is an important equipment to transfer the heat released by the reactor to the steam generator.Therefore,to ensure the safety of the operation of the intermediate heat exchanger can not only guarantee the normal and efficient work of the nuclear power plant,but also have important significance for the protection of the environment.In the intermediate heat exchanger,the tube bundles are arranged in the form of concentric circles.Therefore,the hydrodynamic instability and coupling vibration of concentric tube bundles are studied by means of water tunnel test and numerical simulation.In this paper,the design of concentric tube bundles tunnel test,and utilization of water filling,the visualization window and high-speed photography device records the test results of concentric tube bundles in the radio of radial distance and diameter as follows: 1.28,1.4,and 1.5,and the vibration characteristic of the tube bundles is obtained by data processing,the results show that the three groups of tube bundles corresponds to the critical velocity 1.425 m/s,1.106 m/s and 1.006 m/s.Provided in this paper,the fluid-structure coupling models of concentric tube bundles were established by the commercial software ANSYS CFX under different radial distance of the fluid-structure coupling model,the calculation results were in good agreement compared with tunnel test results found,and by the numerical simulation method to study the concentric arrangement fluid elastic instability characteristics of tube bundles,the tube bundle and the critical velocity of radial distance.In this paper,through the establishment of concentric arrangement bundles of 9 tube of fluid-structural interaction model,calculated the oh rigid tube surrounded the center of the elastic tube at different radial distance,the circumferential distance and the added mass coefficient under central Angle,the tube bundle in the added mass coefficient curves under different parameters,and through the establishment of the elastic tube model,calculated the tube bundle of the coupling frequency,concentric arrangement is studied through simulation of vibration test tube bundle coupling vibration,the results show that occur between the concentric arrangement bundles under the condition of coupling vibration,only increasing the central angle,the coupling vibration of tube bundles will be increased.Only increasing the radial distance or circumferential distance,the difference of bundle amplitude will decrease.