Study of finite element simulation rationality and buckling analysis of tube bundle in shell-and-tube heat exchangers
For the numerical simulation of the buckling of floating head heat exchanger tube bundle with DN300 mm and a heat tube length of 3 m,first,direct binding contact was used to connect the heat exchange tubes and the baffles for nonlinear buckling analysis without considering the gap between the heat exchange tubes and the baffles.The result is that due to the significant increase in the anti-buckling stiffness of the tube bundle,when the equivalent axial pressure on the shell side reaches 42.606 MPa,the tube bundle plastic failure occurs under the action of the axial load without buckling.Then,for the difficulty in nonlinear contact analysis due to gap existing between the heat exchange tube and the baffle,a gap equivalence method is proposed,i.e. filling the gap with a soft material so as to change contact type and realize nonlinear buckling analysis.Meanwhile,the gap equivalent method is used for this floating head heat exchanger to successfully analyze the nonlinear stability analysis of the heat exchanger tube bundle under the shell-side equivalent pressure.It is found that due to no support of the cylinder,the tube bundle will experience overall buckling,and the buckling deformation exhibits an overall deflection.At this time,the equivalent axial pressure is 18.6 MPa,which is smaller than the result of direct binding of the heat exchange tube and the baffle.In addition,the critical pressure of a single tube calculated based on the Euler formula determined by GB/T 151—2014 is 89790 N,which is much larger than the average axial pressure of each tube in the overall buckling in this example,implying that traditional buckling design of shell-and-tube heat exchanger based on Euler formula cannot ensure that the overall buckling of the tube bundle won't occur.
floating head heat exchangershell side pressurecritical pressureoverall buckling of tube bundle
万方数据
维普
