Modelling heat exchanger in Caesar 3

[adilpervaiz]

I am analyzing a B 31.3 piping which connects to a heat exchanger which rests on spring supports. Can anyone help me about how to model a spring supported heat exchanger in Caesar?

 

[XL83NL]

I recently did the same, but then in AutoPIPE (short AP). Shouldnt make a big difference as (AFAIK) both programs use the same approach to determine Code stress for pipe (i.e. use of beam models).

I modelled the HEX as a piece of pipe with (approx.) corresponding properties for flexibility, allthough thats one of the least concerns. The piping will probably be more flexibile than the HEX, so it shouldnt have a big impact.

I made sure the HEX's weight was correctly modelled, and that the supports in AP work the same as the HEX's support. Then I determined if the COG approximately corresponded. Our HEX was supported on a structural steel base frame, under which the constant supports are positioned, to allow the HEX to move equally with the piping. I assumed the frame was far more (i.e. almost infinitely) stiffer than the HEX's support. Therefore, in my AP-model, the constant hangers were attached to the support of the HEX, so I didnt have to model the frame in AP. Here's a snap, the HEX is in red (blue arrow is a concentrated weight to compensate for/model the tube bundle weight)

In real life, the support frame of the HEX has limitations for movement, i.e. it only allows upward movement, no sideways (so wind cant affect it). The reason we had for allowing the HEX to move up/down, rather than making it fixed to the structure and letting the piping do all the work, is outside the scope of this discussion.

 

[adilpervaiz]

Thanks for the help