11. How to model a heat exchanger with connected piping/nozzles in AutoPIPE?

Applies To
Area: Modeling
Date Logged
& Current Version
Sept. 2018


How to model a heat exchanger with connected piping/nozzles in AutoPIPE?


 Start with becoming familiar with the technique used to model a Vessel

Please see the following AutoPIPE help section: 
Help > Contents> Contents Tab> Modeling Approaches> Modeling Approaches> Vessel and Nozzle. 

It is strongly recommended that user take the time to actually perform these example models to better understand the commands and procedure of this modeling approach. 

Step 1 - Create a new model with new pipe properties equal to that of the vessel and connected piping. In this example create 3 new pipe sizes:

PipeID = Vessel, OD = 48", wall thk = std, material =  A106B

PipeID = Loop1, OD = 12", wall thk = std, material =  A106B

PipeID = Loop2, OD = 8", wall thk = std, material =  A106B

Note: user to enter all other pipe properties for pipe ids above as needed.

Step 2 - Insert Vessel piping. Starting at one end insert Run of pipe to each location o support and nozzles connected


Insert Run 

Step 3 - Insert Nozzle piping 

a- select A03, 

b- Convert node point to Tee

c- Select the branch arrow and insert pipe run to inside surface of vessel wall (Pipe OD - wall thk) (node point = B01).

d- Insert nozzle element, length = Wall thickness, radius = radius of Vessel OD (ex. 24"), thickness = thickness of Vessel Wall (yes... again). Select Flexibility method and finish filling in rest of dialog to calculate the nozzle stiffness values, or manually enter them (node point at end of nozzle element = B02. 

If performed correctly, the end of the nozzle element  (ex. B02) should be exactly on the surface of the Vessel.

e- Insert nozzle piping from surface of vessel to flange connection (ex. B03) 

f- Insert Flange element with appropriate settings

g-  In order to account for thermal expansion of the nozzle on the surface of the vessel and disregard added weight , select piping on inside of vessel (ex. A03 to B01),  (Note: best to use Single line mode or Wire-Frame mode to easily select the piping) press Insert> Rigid properties Over Range> disable "Include weight" but enable "Include thermal expansion".

h- Done with Nozzle SO

i- Repeat same technique to insert nozzles at SI (ex. A05), TO (ex. A06), and TI (ex. A07). in the end model should look like this

Note: To save time, one can quickly select the entire branch piping (ex. segment B) and copy/paste to other locations. Then use "Scale" command to flip segment to opposite direction (+y to -y) and  "Modify Pipe properties over range" command to change pipe sizes as needed.


Step 4 - Insert Support legs

a- Select the node points on the vessel where it is to be supported (ex. A02 and A04).

b- Insert support as needed to mimic how the vessel will be supported. In this example, assume guide support connected to ground. Use Insert> Support> type = guide, connected to : ground, gap up = 100, gaps down / left / right = 0.00.

Note: User can insert any kind of frame system and the support could then be connected to a frame node point instead of ground.

See Also

Bentley AutoPIPE