EnginSoft Partnership
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Stress analysis of
a pipe bundle heat exchanger

PROBLEM OVERVIEW
  • Structural integrity assessment of a heat exchanger (E-208A/B) during its start-up, service and shut-down phases
  • Development of a finite element model of the entire exchanger assembly, including the distributor with nozzles, tube sheets, pipe bundle, spherical head, internal vessel, and the bolted connection to the external vessel
  • Multi-step analyses utilizing non-linear material and geometric behavior were carried out under loads mainly due to internal pressure and bolt preload
  • Structural integrity of the heat exchanger was verified according to ASME VIII Div. 2 standard, based on stress categorization and on definition of proper allowable limits as function of stress nature (membrane stress, membrane+bending stress, total stress)
NUMERICAL APPROACH
  • A three-dimensional CAD model wasdeveloped in DesignModeler while the numerical model was created within the DesignSimulation environment (ANSYS WorkBench 11.0)
  • Loading conditions take into account tube-side and shell-side vessel simulation pressure as well as bolt preload at the distributor and external vessel connection
  • The stress analyses performed over the model allowed to certify that the more stressed regions, close to the structural discontinuities, presented anyway acceptable stress states
CUSTOMER

Ravagnan - Italy

AIM

Structural integrity assessment of the heat exchanger E-208A/B during the start-up, service and shut-down phases