Structural Analysis And Optimization Of Large Enamel Bolted Anaerobic Storage Tank

Large enamel bolted anaerobic storage tank is a new product,hereinafter referred to as large bolted storage tank,which has the advantages of short construction period and long service life compared with common types of tank.However,due to the complex stress and improper design,large bolted storage tank still has obvious deformation,tank top collapse,bolt fracture and other phenomena during operation.There are two types of common large bolted storage tanks:membrane top bolted storage tank and steel top bolted storage tank.Aiming at the common problems of membrane top and steel top two typical bolted storage tanks,this paper uses the method of numerical simulation and test to carry out structural mechanics analysis and optimization,which provides a systematic research idea and theoretical basis for its analysis,design,optimization and monitoring.The equivalent numerical model of the whole steel plate of the large bolted storage tank is established by using ANSYS Workbench software.This paper analyzes the stress and deformation distribution of two types of tanks,studies the stress and deformation distribution curve in the direction of tank wall height and thickness,and compares the two types of large bolted storage tanks.The results show that the dangerous points of membrane top bolted storage tank are concentrated on the top tank wall and above,which is centripetal deformation,while the dangerous points of steel top bolted storage tank are located on the lower tank walls,which is bulging deformation;the closer the membrane top bolted storage tank is to the wall thickness of the top tank wall,the more obvious the axial downward deformation is,the more linear the stress is,and the closer the steel top bolted storage tank is to the inner wall,the axial upward deformation is The more obvious,the stress changes in the form of quadratic function.Through the analysis,the modeling analysis method of large bolted storage tank is formed.The self-made bolt pre tightening sensor and anti slip test specimens are manufactured and manufactured.The tightening torque coefficient and anti slip coefficient of bolts are measured.Through the coefficient,the top bolt joint of large bolted storage tank is analyzed and the wall bolt joint is optimized.The results show that the bolts at the top of membrane bolted storage tank are subject to shear force,and the connecting bolts are pressure bearing type;the bolts at the top of steel bolted storage tank are not subject to shear force,and the connecting bolts are friction type;the bolt connecting joints can almost meet the equal strength requirements,and the equal strength ratio factor is about 0.45～0.6.Combined with the characteristics and equivalent analysis of bolted joints in large bolted storage tanks,the analysis method of bolted joints on tank top and the optimization method of bolted joints on tank wall are formed.Based on the numerical model,the influence of structural parameters and working condition parameters on the stress,deformation and bolt force of the large bolted storage tank is analyzed.Meanwhile,the influence of parameters on the main beam pressure of the steel bolted storage tank is analyzed.The orthogonal test is designed to analyze the influence of structural parameters on the stress and deformation of the large bolted storage tank,and the optimal scheme is determined.The results show that the height of the central column has a great influence on the stress and deformation of the membrane top bolted storage tank,the thickness of the bottom tank wall has a great influence on the stress and the angle of the hoop angle has a great influence on the deformation of the steel top bolted storage tank.The field safety monitoring test is carried out for the tank manufactured according to the optimized scheme,and the test results verify the reliability of the numerical analysis and optimization.Combined with the structural characteristics of large bolted storage tank,this paper solves the modeling problem of large bolted storage tank,analyzes the dangerous points of the tank and the strength of bolt joint,which provides ideas and theoretical support for the design optimization of large bolted storage tank.