AutoPIPE - How to design a stacked heat exchanger?

Overview of a Stacked Heat Exchanger

A stacked heat exchanger arrangement consists of two or more shell‑and‑tube heat exchangers installed vertically, one above the other, and operating as a single thermal system.
In this configuration, the process fluid flows continuously from the first exchanger into the next, allowing the heat transfer initiated in the first exchanger to continue through the stacked units.

Limitations for Modeling Stacked Heat Exchangers in AutoPIPE Vessel

When using the Stacked option, the following limitations apply:

1. Identical Shell Outside Diameters Required
  The outside diameters (OD) of the shells on both the tube side and shell side must be identical for all stacked exchangers.
  Differing shell diameters are not supported in a stacked configuration.
2. Goose‑Neck (Elbow) Nozzles Not Supported
  Goose‑neck (elbow‑type) inlet or outlet nozzles cannot be used when modeling stacked heat exchangers.
  Only straight, axially aligned nozzles are supported to maintain continuity between stacked units.

Failure to meet these requirements may result in unsupported behavior or unexpected results [for example, nozzle projection increases while zoom in into GUI]

How to Model a Stacked Heat Exchanger

Follow the steps below to model a stacked heat exchanger in AutoPIPE Vessel:

1. Open the Shell and Tube Heat Exchanger Properties dialog box.
2. Navigate to the Geometry tab.
3. Enable the Stacked option.
4. Ensure that the inlet and outlet options are selected correctly for both the shell side and tube side, as required for stacked operation.
5. Selecting the Stacked option automatically creates two identical heat exchangers stacked vertically, and the model should be treated as a single exchanger during the remainder of the design process.
6. Continue modeling the exchanger as if designing a single unit, including loads, supports, and attachments.
7. Once completed, It will automatically create 2 identical exchangers stacked on top of each other as shown below:

Saddle Modeling Note

If the saddles do not appear for either the top or bottom exchanger:

1. Open the Saddle properties for the exchanger.
2. Select saddle option SB & ST to and click OK.
3. Repeat for second saddle.