On the design of the tubesheet and the tubesheet-to-shell junction of a fixed tubesheet heat exchanger

Abstract

For the (mechanical) design of an existing fixed tubesheet heat exchanger, a C2-Hydrogenation reactor in a petrochemical plant, various code solutions are compared with each other and with a Finite Element solution based on the Direct Route in Design by Analysis (EN 13445-3, Annex B). The codes and standards used in the investigation are ASME Section VIII, Division 1 and EN 13445-3, Clause 13 and Annex J. The ASME VIII/2 and TEMA codes are not appropriate for this design. The ASME VIII/1 and EN 13445-3 Clause 13 approaches are similar. Differences in maximum permissible pressures result partly from different nominal design stresses. The modern EN 13445-3 Annex J approach, being based on limit analysis theory, leads to very different, much more efficient results. The Direct Route in Design by Analysis confirms the EN 13445-3 Annex J results, but gives, at the same time, clear insight into the behaviour of the whole structure and the various maximum permissible pressure limiting details.