FEPG-Based Exploitation Of Finite Element Program And Stress Analysis Of The Kettle-Type Reboiler With Fixed Tubesheet

In virtue of the finite element program generator (FEPG) and its preprocessing multi-table information (MTI), the finite element models and calculating programs of the fixed tube-sheet exchanger were worked out and embedded in VAS2.0 software. By dint of the exploited modules, the interface programs from VAS2.0 to ANSYS and the ANSYS software, a 3-D entire model of kettle-type reboiler with fixed tube sheet was constructed for stress analysis. With the aid of ANSYS, a 3-D simplified model of the slant conical shell on the reboiler was established in APDL and stress analysis was done.The high temperature character was fully considered and the equivalent coefficients of heat transfer were used while analyzing the thermal load of the reboiler, with which the scale of the entire model was effectively reduced. By the calculation of the stead-state temperature field, the temperature distribution was obtained and accordingly the thermal stress was analyzed. After the thermal load and the pressure load influence on the reboiler under four risk load cases was discussed, the most risky case was affirmed. Based on the JB4732-95 "Steel PressureVessels------Design by Analysis", strength evaluations of the reboiler were carried out. With theentire model, the slant conical shells with different maximum slant conical angle were analyzed, the influence of the maximum slant conical angle on the stress distribution of the tube sheet was obtained, and the stress distribution of the slant conical shell was discussed.Moreover, with the simplified model of the slant conical shell, the influence of the different dimensions of the slant conical shell on the stress distribution of the slant conical shell was analyzed. By comparing the results of the entire model and the simplified model, it shows that the simplified model gives reasonable results, which offers a simple and effective modeling method for the slant conical shell on the this kind of reboiler. The stress level factors(SLFs) based on design by analysis in the big side knuckle region were obtained for the slant conical shell with various dimensions.