Stress analysis of
a pipe bundle heat exchanger

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)

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