Analysis Of Force Non-uniformity Of Chemical Equipment Flange

As an important sealing component of Chemical equipment and Oil and Gas pipelines,flange connection plays an extremely important role in the safe operation of equipment.Because of its good sealing performance,convenient replacement and high strength,it is widely used in petrochemical,defense engineering and aerospace industries.Taking the tube box flange of the heat exchanger as the research object this paper analyzes the stress distribution non-uniformity of the flange connection under preloading conditions and operating conditions,and discusses the non-uniform preloading of the bolt and the stress distribution and deformation of flanges,gaskets and bolts under the condition of coupling with the inhomogeneous temperature field.The work done in this paper is as follows:(1)Flange connection structure is appropriately simplified and its force and deformation were analyzed based on the elastic theory,and the force balance equation of the flange connection was obtained.(2)Based on the non-linear characteristics of the gasket material,a three-dimensional simulation model of the flange connection was established.Under the preload conditions,the non-uniform preloading model of bolts was analyzed to obtain the stress distribution and deformation law.The uneven distribution of stress increases.Flange connection heat transfer model was established and the inhomogeneous temperature field coupled simulation model was analyzed.It can be concluded that the sealing effect is different in different areas of the sealing gasket in the inhomogeneous temperature field,and the flange structure is easy to seal and fail.(3)The concept of non-uniformity of stress distribution was proposed,an index to evaluate the non-uniformity of stress distribution was set up,and the finite element simulation data was calculated by the use of MATLAB software.Meanwhile,the influence of the load fluctuation amplitude under preload and operating conditions on the inhomogeneous coefficient of the stress distribution of the bottom surface,gasket,and bolt cross section was analyzed.It is shown that as the load fluctuation amplitude increases in the inhomogeneous temperature field,the gasket inhomogeneous coefficient increases and the uniformity of gasket stress distribution decreases.(4)Through the analysis of the tightness of flange connection,the fluctuation amplitudeof bolt preload and flange deformation under the effect of inhomogeneous temperature field was obtained,and the tightness of flange connection in inhomogeneous temperature field was evaluated.On the basis of the gained non-uniformity of the flange joint force,the relationship between the inhomogeneous coefficient and the compactness parameters of the force distribution of the gasket was obtained.