migrate heat exchanger network to the hensmith package

.github/workflows/build.yml

@@ -58,6 +58,7 @@ jobs:
         pip install --no-cache-dir git+https://github.com/CalebBell/thermo.git
         pip install --no-cache-dir git+https://github.com/BioSTEAMDevelopmentGroup/thermosteam.git
         pip install --no-cache-dir git+https://github.com/BioSTEAMDevelopmentGroup/Bioindustrial-Park.git
+        pip install --no-cache-dir --no-deps git+https://github.com/BioSTEAMDevelopmentGroup/hensmith.git
         pip install -r requirements_test.txt
         pip install --no-cache-dir git+https://github.com/QSD-Group/QSDsan.git
         pip install --no-cache-dir git+https://github.com/QSD-Group/EXPOsan.git

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "How2STEAM"]
 	path = How2STEAM
 	url = https://github.com/BioSTEAMDevelopmentGroup/How2STEAM.git
+[submodule "hensmith"]
+	path = hensmith
+	url = https://github.com/BioSTEAMDevelopmentGroup/hensmith.git

biosteam/__init__.py

@@ -13,7 +13,7 @@
 
 """
 from __future__ import annotations
-__version__ = '2.53.11'
+__version__ = '2.54.0'
 
 #: Chemical engineering plant cost index (defaults to 567.5 at 2017).
 CE: float = 567.5 
@@ -79,14 +79,29 @@ def njit(*args, **kwargs):
 from . import report
 from . import _settings
 
-__all__ = (
+__all__ = [
     'Unit', 'PowerUtility', 'UtilityAgent', 'HeatUtility', 'Facility',
     'utils', 'units', 'facilities', 'wastewater', 'evaluation', 'Chemical', 'Chemicals', 'Stream',
     'MultiStream', 'settings', 'exceptions', 'report', 'units_of_measure',
-    'process_tools', 'preferences', *_system.__all__, *_flowsheet.__all__, 
+    'process_tools', 'preferences', *_system.__all__, *_flowsheet.__all__,
     *_tea.__all__, *units.__all__, *facilities.__all__, *wastewater.__all__,
     *evaluation.__all__, *process_tools.__all__, *_module.__all__,
-)
+]
+
+# %% Load premire biosteam extensions which offer comprehensive simulation capabilities.
+
+# Add heat exchanger network synthesis capabilities from hensmith library.
+try:
+    import hensmith
+except ModuleNotFoundError as error:
+    if error.name != 'hensmith': raise
+else:
+    del hensmith
+    __all__.append('HeatExchangerNetwork')
+
+# Future extensions can be added here.
+
+# %% Non-essential representation features.
 
 def nbtutorial(dark=False):
     global print_error

biosteam/_unit.py

@@ -247,7 +247,10 @@ def __init_subclass__(cls,
         name = cls.__name__
         if hasattr(bst, 'units') and hasattr(bst, 'wastewater') and hasattr(bst, 'facilities'):
             # Add 3rd party unit to biosteam module for convenience
-            if name not in bst.units.__dict__:
+            if isinstance(cls, bst.Facility):
+                if name not in bst.facilities.__dict__:
+                    bst.facilities.__dict__[name] = cls
+            elif name not in bst.units.__dict__:
                 bst.units.__dict__[name] = cls
             if name not in bst.__dict__:
                 bst.__dict__[name] = cls

biosteam/facilities/__init__.py

@@ -17,7 +17,6 @@
 from ._cleaning_in_place import *
 from ._refrigeration_package import *
 from ._fire_water_tank import *
-from .hxn import *
 from .systems import *
 
 from . import _chemical_capital_investment
@@ -30,7 +29,6 @@
 from . import _cleaning_in_place
 from . import _refrigeration_package
 from . import _fire_water_tank
-from . import hxn
 from . import systems
 
 __all__ = (
@@ -44,6 +42,10 @@
     *_cleaning_in_place.__all__,
     *_refrigeration_package.__all__,
     *_fire_water_tank.__all__,
-    *hxn.__all__,
     *systems.__all__,
 )
+
+# HeatExchangerNetwork lives in the hensmith package and is bound into this
+# namespace by hensmith/__init__.py once biosteam has finished initializing
+# (see the end of biosteam/__init__.py). It must stay out of __all__: biosteam
+# star-imports this module before hensmith can bind it.