Study On The Dynamic Characteristics Of Desulfuration Tower With Influences Of Fluid-solid Coupling In The Rare Earthquake Action

With the continuous development of national economy and enhancement of environmentalprotection, smoking desulfuration tower engineering for large thermal power plants areunceasingly advancing. And considering the electric power engineering as the important part ofthe city life line system, it is very important to ensure the safety of electric power plants and theaccessory structures. As the absolutely necessary part of the electric power system, thedesulfuration tower has quite complex structural form, and in China there is no specific code atpresent to apply for its structure designing. Once damages are caused to the structure in theearthquake action, it will have serious influences on post-earthquake rescue work, even possiblyresulting in secondary disaster. In addition, our country often suffers from the earthquakedisaster, and since the20th century, there have been600,000, people dead in the earthquake,accounting for about40%of the global casualties amount, which is almost1,500,000, people.Consequently, great attention has been paid to research on the dynamic characteristics of thecomplex desulfuration tower, thus study of the structural seismic response has become a focus.And considering the economic factors, it still needs further study on how to improve its seismicperformances.The main content of this paper is based on the current structure designing research on thedesulfuration tower in domestic and abroad, and comparing with the analyzing models andprinciples of the similar structures, the various influencing factors are summarized for thedesulfuration tower dynamic characteristics. Considering the fluid-solid coupling and thestructural directivity, the seismic response analysis of the desulfuration tower is conducted, andthe stress distribution and displacement of the structure are further investigated.The research object in this paper is a large thin-walled steel cylinder structure, in whichtwo big hatches are opened at one side as the desulfuration tower flues in order to meet thetechnological requirements, and about1/3of inner space is filled with liquid in order todesulfurate the flue gas. It not only has complex force situation but also has unsymmetricalstructure, so the time-history analysis method is adopted to analyze the structural dynamicresponse in the earthquake action. By using the ANSYS software, two types of finite elementmodels were established separately before and after considering the liquid-structure interaction,in order to review the seismic performance of the desulfuration tower. Then the seismic responses of the desulfuration tower were analyzed when the rare earthquake wave was inputseparately in the X direction and the Y direction, and both the structure distortions and stresschanges were reviewed, thus the influence of liquid on the tower structure was discussed andthe relative weak regions of the structure are confirmed.The research results reveal that the big hatches and the fluid-solid interaction both havegreat influences on smoking desulfuration tower structure.1) The unsymmetrical characteristicof the structure has great affect on dynamic response of the desulfuration tower. It is mainlybecause the big hatches becomes the weak region of the whole structure, and in this directionthe structure rigidity is weakened, which has a more severe influence on the stress distributionof the desulfuration tower.2) The fluid-solid interaction has a great influence on the structuredisplacement and stress distribution of the desulfuration tower. The fluid inside couldsimultaneously weaken and strengthen the rare earthquake action on the tower structure.Exactly speaking, at the earlier time of the earthquake action, the seismic response of thedesulfuration tower is weakened, while at the evening time it is strengthened dramatically.3) Itis also revealed from the dynamic response analysis results that the cross beams with the aroundconjoint wall areas and the flue gas hatch area have become the weak regions of thedesulfuration tower. Therefore, some reinforcement measures should be taken to the aboveareas, so that the seismic performance of the desulfuration tower could be improved.