Add heat exchanger performance and cost components by bayc · Pull Request #418 · NatLabRockies/H2Integrate

bayc · 2025-12-18T19:57:44Z

Add HX performance and cost components

This PR adds a simple heat exchanger model, along with a preliminary cost-scaling model.

Section 1: Type of Contribution

Section 2: Draft PR Checklist

Open draft PR
Describe the feature that will be added
Fill out TODO list steps
Describe requested feedback from reviewers on draft PR
Complete Section 7: New Model Checklist (if applicable)

TODO:

Have TLDRD team review implementation of model.
Add documentation.
Determine whether an example is needed now or later (once other heat components get added).
Re-work the tests to be more streamlined in the checking of asserts.
Ask for reviews from H2I team once above are complete.

Type of Reviewer Feedback Requested (on Draft PR)

Structural feedback:

Feedback on the addition of a heat folder to the converters directory.

Implementation feedback:

Feedback on the testing methods once they are updated (not yet).

Other feedback:

Section 3: General PR Checklist

PR description thoroughly describes the new feature, bug fix, etc.
Added tests for new functionality or bug fixes
Tests pass (If not, and this is expected, please elaborate in the Section 6: Test Results)
Documentation
- Docstrings are up-to-date
- Related docs/ files are up-to-date, or added when necessary
- Documentation has been rebuilt successfully
- Examples have been updated (if applicable)
CHANGELOG.md has been updated to describe the changes made in this PR

Section 3: Related Issues

Section 4: Impacted Areas of the Software

Section 4.1: New Files

path/to/file.extension
- method1: What and why something was changed in one sentence or less.

Section 4.2: Modified Files

path/to/file.extension
- method1: What and why something was changed in one sentence or less.

Section 5: Additional Supporting Information

Section 6: Test Results, if applicable

Section 7 (Optional): New Model Checklist

alidor85 · 2026-01-23T18:59:39Z

+    """_summary_
+    This is a very simple placeholder cost model:
+
+    - Reference: 240,000 USD for a 1 MW HX with U ~ 1000 W/m²-K


I don't know the source for this function, I would rather use something from a chemical plant design handbook.
From Sinott and Towler (2021):
U-tube shell and tube HX:
Total installed costs = [(a+b*S^n) * f_year * f_install * f_material]
a = 28000
b = 54
n = 1.2
S - heat transfer area in m^2
limits: 10 m^2 <= S <= 1000 m^2

This is in CEPCI index = 532.9 so need to be converted (it's for Jan. 2010)
To get it to 2022 USD f_year = 816/532.9

f_install = 1.61 (default, maybe let the user add their own?)

It also assums simple carbon steel, so we need to account for materials once temperatures are higher
f_material = 1 for carbon steel (should be a default value), if user specifies another more expensive material they should include f_material

For the OpEx I am not sure we want to include it in a cost function, this should be in the general economic calculation (like ProFAST)

alidor85 · 2026-01-23T19:01:10Z

+        exp_Q = inputs["exp_Q"][0]
+
+        scale_Q = (Q_total_W / Q_ref) ** exp_Q if Q_total_W > 0 else 0.0
+        capex = C_ref * scale_Q


Do we want to add installation factor in here, or are those things usually accounted for elsewhere in H2I analysis?
I think in ther steel paper at least the cost functions are for totat installed costs

elenya-grant

Howdy Chris! I'm not sure whether this is ready for a full in-depth review yet but I left a few small comments and did a quick review (I will do another deeper-review once this is not longer a draft). Overall it seems like some very useful and cool functionality! Thanks for the work on this!

Some higher-level notes are:

heat_exchanger_model/hx_shell_tube_steady.py: more inline comments and docstrings would be helpful in the functions defined in here
Could you update the performance model to use the recently introduced PerformanceModelBaseClass? I'd be happy to help here if needed!
Don't forget to add the performance and cost model(s) to supported_models.py

elenya-grant · 2026-02-09T17:06:50Z

+    D_o_m: float = field(validator=gt_zero)
+    t_wall_m: float = field(validator=gt_zero)
+    D_shell_m: float = field(validator=gt_zero)
+    cost_year: int = field(validator=gt_zero)


why is cost year an input to the performance model config? Doesn't look like its used in this model

elenya-grant · 2026-02-09T17:07:41Z

+
+        # Setup OpenMDAO inputs
+        self.add_input(
+            "Th_in_C", val=self.config.Th_in_C, units="C", desc="Hot fluid inlet temperature"


units="degC", "C" is Coulombs in OpenMDAO units

elenya-grant · 2026-02-09T17:08:11Z

+        )
+
+        # Setup OpenMDAO outputs
+        self.add_output("Th_out_C", val=0.0, units="C", desc="Hot fluid outlet temperature")


Same note about units being degC instead of C

elenya-grant · 2026-02-09T17:11:44Z

+            "D_shell": self.config.D_shell_m,
+        }
+
+        res = hx_shell_tube_steady(params)


I kind of feel like whatever logic is done in the hx_shell_tube_steady() function should be replaced in ShellTubeHXPerformanceModel as a method

elenya-grant · 2026-02-09T17:17:28Z

+            "Tc_in_C", val=self.config.Tc_in_C, units="C", desc="Cold fluid inlet temperature"
+        )
+        self.add_input(
+            "m_dot_h_kg_s",


I don't think these input and output names should have units in them - because it gets confusing if I did prob.model.get_val("hx.m_dot_h_kg_s", units="kg/h"). I do think units are appropriate for the config input names

elenya-grant · 2026-02-09T17:27:35Z

+    Th_in_C: float = field(validator=gt_zero)
+    Tc_in_C: float = field(validator=gt_zero)
+    m_dot_h_kg_s: float = field(validator=gt_zero)
+    m_dot_c_kg_s: float = field(validator=gt_zero)


I understand that the h and c in the variable names mean "hot" and "cold" but I think that it'd be nice to have the "hot" and "cold" within the variable names themselves, something like:

Temp_hot_C or Hot_temp_C

Temp_cold_C or Cold_temp_C

Hot_mass_flow_rate_kg_s

elenya-grant · 2026-02-09T17:30:55Z

+        cost_year (int): Year for cost estimation.
+    """
+
+    Th_in_C: float = field(validator=gt_zero)


Perhaps this relates to PR #480, but I think that this could be generalized to just define the two commodities coming into the heat exchanger. Then in ShellTubeHXPerformanceModel, the inputs would be something like: f"{commodity1}_in_temp", f"{commodity2}_in_temp", f"{commodity1}_in", f"{commodity2}_in".

Is the "hot" thing in just hotter than the "cold" thing in (if so - then the model could see which one is hotter rather than having the user define it). Or is the "hot" thing the thing getting heated?

…into feature/heat_exchanger

…nger

bayc added 2 commits December 18, 2025 12:46

add shell tube heat exchanger peformance model and test

1db1ccb

add shell tube heat exchanger cost model and test

ebe2fcc

bayc self-assigned this Dec 18, 2025

bayc added enhancement New feature or request in progress labels Dec 18, 2025

bayc marked this pull request as draft December 18, 2025 19:58

bayc force-pushed the feature/heat_exchanger branch 5 times, most recently from 5cf34b2 to 8c1bcb7 Compare December 18, 2025 20:50

pre-commit formatting

a693f1c

bayc force-pushed the feature/heat_exchanger branch from 8c1bcb7 to a693f1c Compare December 18, 2025 20:58

bayc commented Jan 6, 2026

View reviewed changes

Comment thread h2integrate/converters/heat/shell_tube_hx_cost_model.py Outdated

bayc commented Jan 6, 2026

View reviewed changes

Comment thread h2integrate/converters/heat/test/test_shell_tube_hx.py Outdated

Merge branch 'develop' into feature/heat_exchanger

137ae08

elenya-grant self-requested a review January 22, 2026 20:39

alidor85 reviewed Jan 23, 2026

View reviewed changes

update costmodelbaseconfig import

3173feb

elenya-grant requested changes Feb 9, 2026

View reviewed changes

johnjasa and others added 4 commits February 12, 2026 10:57

Merge branch 'develop' into feature/heat_exchanger

94dd5a8

Merge branch 'develop' into feature/heat_exchanger

36749c5

Merge branch 'feature/heat_exchanger' of github.com:bayc/H2Integrate …

788016c

…into feature/heat_exchanger

Merge remote-tracking branch 'origin/develop' into feature/heat_excha…

8719f70

…nger

bayc closed this Apr 15, 2026

bayc added 4 commits April 17, 2026 16:44

udpate tests

88e0a95

Merge remote-tracking branch 'origin/develop' into feature/heat_excha…

bb9c489

…nger

updates due to changes in develop

affd61e

Merge remote-tracking branch 'origin/develop' into feature/heat_excha…

61eab03

…nger

bayc added 2 commits May 21, 2026 11:37

Merge remote-tracking branch 'origin/develop' into feature/heat_excha…

092f51e

…nger

Merge remote-tracking branch 'origin/develop' into feature/heat_excha…

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…nger

bayc reopened this Jul 22, 2026

pre-commit formatting

f9bfe3a

bayc force-pushed the feature/heat_exchanger branch from 445a159 to f9bfe3a Compare July 22, 2026 15:58

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Add heat exchanger performance and cost components - #418

Add heat exchanger performance and cost components#418
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alidor85 Jan 23, 2026 •

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bayc commented Dec 18, 2025

Add HX performance and cost components

Section 1: Type of Contribution

Section 2: Draft PR Checklist

TODO:

Type of Reviewer Feedback Requested (on Draft PR)

Section 3: General PR Checklist

Section 3: Related Issues

Section 4: Impacted Areas of the Software

Section 4.1: New Files

Section 4.2: Modified Files

Section 5: Additional Supporting Information

Section 6: Test Results, if applicable

Section 7 (Optional): New Model Checklist

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alidor85 Jan 23, 2026 •

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