save users from themselves

idaes/models/properties/modular_properties/base/tests/test_utility.py

@@ -710,7 +710,6 @@ def test_all_types_components(self):
         )
 
         m.props = m.params.build_state_block([1], defined_state=False)
-
         l_phase, v_phase, vl_comps, henry_comps, l_only_comps, v_only_comps = (
             identify_VL_component_list(m.props[1], ("p1", "p2"))
         )
@@ -721,6 +720,102 @@ def test_all_types_components(self):
         assert l_only_comps == ["b"]
         assert v_only_comps == ["c"]
 
+    @pytest.mark.unit
+    def test_henry_components_only(self):
+        m = ConcreteModel()
+        m.params = DummyParameterBlock(
+            components={
+                "b": {
+                    "valid_phase_types": PT.liquidPhase,
+                },
+                "c": {
+                    "valid_phase_types": PT.vaporPhase,
+                },
+                "d": {
+                    "valid_phase_types": PT.solidPhase,
+                },
+                "e": {
+                    "parameter_data": {"henry_ref": {"p1": 86}},
+                    "henry_component": {
+                        "p1": {"method": ConstantH, "type": HenryType.Kpx}
+                    },
+                },
+            },
+            phases={
+                "p1": {
+                    "type": LiquidPhase,
+                    "equation_of_state": DummyEoS,
+                },
+                "p2": {
+                    "type": VaporPhase,
+                    "equation_of_state": DummyEoS,
+                },
+                "p3": {
+                    "type": SolidPhase,
+                    "equation_of_state": DummyEoS,
+                },
+            },
+            state_definition=self,
+            pressure_ref=100000.0,
+            temperature_ref=300,
+            base_units=self.base_units,
+        )
+
+        m.props = m.params.build_state_block([1], defined_state=False)
+        l_phase, v_phase, vl_comps, henry_comps, l_only_comps, v_only_comps = (
+            identify_VL_component_list(m.props[1], ("p1", "p2"))
+        )
+        assert l_phase == "p1"
+        assert v_phase == "p2"
+        assert vl_comps == []
+        assert henry_comps == ["e"]
+        assert l_only_comps == ["b"]
+        assert v_only_comps == ["c"]
+
+    @pytest.mark.unit
+    def test_no_vle_components(self):
+        m = ConcreteModel()
+        m.params = DummyParameterBlock(
+            components={
+                "b": {
+                    "valid_phase_types": PT.liquidPhase,
+                },
+                "c": {
+                    "valid_phase_types": PT.vaporPhase,
+                },
+                "d": {
+                    "valid_phase_types": PT.solidPhase,
+                },
+            },
+            phases={
+                "p1": {
+                    "type": LiquidPhase,
+                    "equation_of_state": DummyEoS,
+                },
+                "p2": {
+                    "type": VaporPhase,
+                    "equation_of_state": DummyEoS,
+                },
+                "p3": {
+                    "type": SolidPhase,
+                    "equation_of_state": DummyEoS,
+                },
+            },
+            state_definition=self,
+            pressure_ref=100000.0,
+            temperature_ref=300,
+            base_units=self.base_units,
+        )
+
+        m.props = m.params.build_state_block([1], defined_state=False)
+        with pytest.raises(
+            PropertyPackageError,
+            match="Phase pair p1-p2 was identified as "
+            "being a VLE pair, however are no components present in both "
+            "the vapor and liquid phases simultaneously.",
+        ):
+            _ = identify_VL_component_list(m.props[1], ("p1", "p2"))
+
 
 # Property configuration for pure water to use in bubble and dew point tests
 configuration = {

idaes/models/properties/modular_properties/base/utility.py

@@ -374,6 +374,13 @@ def identify_VL_component_list(blk, phase_pair):
         elif (v_phase, j) in blk.phase_component_set:
             v_only_comps.append(j)
 
+    if len(vl_comps) == 0 and len(henry_comps) == 0:
+        raise PropertyPackageError(
+            f"Phase pair {phase_pair[0]}-{phase_pair[1]} was identified as "
+            "being a VLE pair, however are no components present in both "
+            "the vapor and liquid phases simultaneously."
+        )
+
     return l_phase, v_phase, vl_comps, henry_comps, l_only_comps, v_only_comps
 
 

idaes/models/properties/modular_properties/state_definitions/FTPx.py

@@ -383,9 +383,8 @@ def state_initialization(b):
     else:
         _pe_pairs = b.params._pe_pairs
 
-    vl_comps = []
-    henry_comps = []
-    init_VLE = False
+    num_VLE = 0
+
     for pp in _pe_pairs:
         # Look for a VLE pair with this phase - should only be 1
         if (
@@ -395,7 +394,7 @@ def state_initialization(b):
             b.params.get_phase(pp[1]).is_liquid_phase()
             and b.params.get_phase(pp[0]).is_vapor_phase()
         ):
-            init_VLE = True
+            num_VLE += 1
             # Get bubble and dew points
             tbub = None
             tdew = None
@@ -409,10 +408,6 @@ def state_initialization(b):
                     tdew = b.temperature_dew[pp].value
                 except KeyError:
                     pass
-            if len(vl_comps) > 0:
-                # More than one VLE. Just use the default initialization for
-                # now
-                init_VLE = False
             (
                 l_phase,
                 v_phase,
@@ -423,7 +418,7 @@ def state_initialization(b):
             ) = identify_VL_component_list(b, pp)
             pp_VLE = pp
 
-    if init_VLE:
+    if num_VLE == 1:  # Only support initialization when a single VLE is present
         henry_mole_frac = []
         henry_conc = []
         henry_other = []
@@ -471,7 +466,7 @@ def state_initialization(b):
 
     # Default is no initialization of VLE
     vap_frac = None
-    if init_VLE:
+    if num_VLE == 1:
         raoult_init = False
         if tdew is not None and b.temperature.value > tdew:
             # Pure vapour