Mises Stress And Modal Analysis Of Desulfurization Tower Structure And Optimization Based On Beam And Shell Unit

The FGD(flue gas desulfurization)tower plays a significant role in coal-fired generating unit of thermal power plant.It has the features of large diameter,small thickness and high height-to-diameter ratio.There's no specific reference for design of this non-standard equipment.Facing the fact that the design process is always lack of theoretical analysis and guidance,due to the complicated structure,the tower is always completed uneconomical.As a result,unnecessary material waste is caused,which makes it difficult to reduce costs.This is a common phenomenon in the industry.The following investgation are completed in this paper:Firstly,a geometric model of the FGD tower structure which is simplified and conformed to the actual project has been established.The FGD tower is a thin-walled cotainer.Because of its feature,the tower has many openings,complicated structures and complex loads conditions,moreover,the thickness of the wall is much smaller than the diameter of the tower.Hence,the adoption of B31 element(based on the Timoshenko beam theory)and S4 R element(based on the Reissner-Mindlin shell theory)should ensure the high accuracy and low computational complexity.Secondly,it is analyzed the tower structure according to the distribution of Mises stress.Though the strength of the structure meets the strength limit of the material,the reinforce still need to be added to those position with high local stress.Based on the modal analysis,the complicated of the loading distribution and tower structures stiffness,the necessity of resonance prevention has been declared.Preliminary conclusions have been obtained from those researches above:The maximum stress in the whole structure of the FGD tower appears on the internal support beams.The local structure damage on the wall generally occurs at those positions: support beams' joints,diameter-changing sections and rectangular openings.The FGD tower may easily become unstable because of its complicated structure,uneven distribution of internal loads and rigidity.Hence,it is extremely disadvantageous for equipment operation and personnel security.These conclusions and laws can provide some references for similar structures designs.Figure28 Table11 Reference53...