Theory And Experimental Analysis About Sealing Property Of Clad Tubesheet Hydraulic Expanded Joint

Heat exchangers are being widely used during production and living as a kind of important process equipment. There exist several connecting formats of tube and tube-sheet, and because the advantages of hydraulic expansion are obvious, such as high quality、high efficiency、low residual stress after hydraulic expansion and can be easily controlled, the hydraulic expansion is widely employed in the connecting of tube and tube-sheet. There exist stainless steel clad layer inside of tube-sheet to resist the corrosion by shell side medium and prevent the medium leaking from tube surface. In this paper correlational research is conducted to develop suitable solution, and the main contents are as follows:1. The residual contact pressure of tube and tube-sheet with linear-power relation between stress and strain is calculated by elastic-plastic method. The equations for solving residual contact pressure are derived, and the theoretical solution is compared with the finite element calculation results so as to prove the accuracy of theoretical calculation.2. Different numerical models are built with Abaqus to calculate the residual contact pressure. The most suitable model is determined for numerous calculations by the comparative results.3. The residual contact pressure of hydraulic expanded joint under different groove width、different groove height and different expanding pressure is calculated and compared, and the relation between residual contact pressure and groove width、groove height、expanding pressure is analyzed to determine the best parameters for the best expanding effect.4.The influence of initial gap between tube and tube-sheet、 Perpendicularity of tube hole、Gradient of groove edge、Gradient of groove underside and also the integrated factors on hydraulic expanding is calculated and analyzed, so as to provide a reference for manufacture.5. The test model is designed and the test plan is made on the basic of numerical calculation results. The machining quality of test model is strictly ensured and reasonable steps are taken to carry out the test.6. A residual contact pressure calculating program is written by VB programming language、Python programming language and APDL programming language. Different models are designed in the program, and the program can perform automatic calculation about hydraulic expanding.