Dewatering and thickener unit models BSM2 (#1010)

* dewtering unit model

* removing imports

* black

* black and doc error

* testing scaling

* pylint errors 1

* change blk to self

* pylint errors 2

* adding test and list error

* thickener unit model

* unit consistency check

* applying comments

* fix typo

* fix typo 2

* Update watertap/unit_models/thickener.py

Co-authored-by: Adam Atia <[email protected]>

* Update watertap/unit_models/dewatering.py

Co-authored-by: Adam Atia <[email protected]>

* chaine unit name in tests

* changing class name

* cleanup unused imports and add time index to TSS in dewaterer

* remove unused imports from test_dewatering

* more cleanup

---------

Co-authored-by: agarciadiego <>
Co-authored-by: Adam Atia <[email protected]>

watertap/unit_models/__init__.py

@@ -24,3 +24,5 @@
 from .electrodialysis_1D import Electrodialysis1D
 from .gac import GAC
 from .ion_exchange_0D import IonExchange0D
+from .thickener import Thickener
+from .dewatering import DewateringUnit

watertap/unit_models/dewatering.py

@@ -0,0 +1,163 @@
+###############################################################################
+# WaterTAP Copyright (c) 2021, The Regents of the University of California,
+# through Lawrence Berkeley National Laboratory, Oak Ridge National
+# Laboratory, National Renewable Energy Laboratory, and National Energy
+# Technology Laboratory (subject to receipt of any required approvals from
+# the U.S. Dept. of Energy). All rights reserved.
+#
+# Please see the files COPYRIGHT.md and LICENSE.md for full copyright and license
+# information, respectively. These files are also available online at the URL
+# "https://github.com/watertap-org/watertap/"
+#
+###############################################################################
+"""
+Dewatering unit model for BSM2. Based on IDAES separator unit
+
+Model based on 
+
+J. Alex, L. Benedetti, J.B. Copp, K.V. Gernaey, U. Jeppsson,
+I. Nopens, M.N. Pons, C. Rosen, J.P. Steyer and
+P. A. Vanrolleghem
+Benchmark Simulation Model no. 2 (BSM2)
+"""
+# Import IDAES cores
+from idaes.core import (
+    declare_process_block_class,
+)
+from idaes.models.unit_models.separator import SeparatorData, SplittingType
+
+from idaes.core.util.tables import create_stream_table_dataframe
+import idaes.logger as idaeslog
+
+from pyomo.environ import (
+    Param,
+    units as pyunits,
+    Set,
+)
+
+from idaes.core.util.exceptions import (
+    ConfigurationError,
+)
+
+__author__ = "Alejandro Garciadiego"
+
+
+# Set up logger
+_log = idaeslog.getLogger(__name__)
+
+
+@declare_process_block_class("DewateringUnit")
+class DewateringData(SeparatorData):
+    """
+    Dewatering unit block for BSM2
+    """
+
+    CONFIG = SeparatorData.CONFIG()
+    CONFIG.outlet_list = ["underflow", "overflow"]
+    CONFIG.split_basis = SplittingType.componentFlow
+
+    def build(self):
+        """
+        Begin building model.
+        Args:
+            None
+        Returns:
+            None
+        """
+
+        # Call UnitModel.build to set up dynamics
+        super(DewateringData, self).build()
+
+        if "underflow" and "overflow" not in self.config.outlet_list:
+            raise ConfigurationError(
+                "{} encountered unrecognised "
+                "outlet_list. This should not "
+                "occur - please use overflow "
+                "and underflow as outlets.".format(self.name)
+            )
+
+        self.p_dewat = Param(
+            initialize=0.28,
+            units=pyunits.dimensionless,
+            mutable=True,
+            doc="Percentage of suspended solids in the underflow",
+        )
+
+        self.TSS_rem = Param(
+            initialize=0.98,
+            units=pyunits.dimensionless,
+            mutable=True,
+            doc="Percentage of suspended solids removed",
+        )
+
+        @self.Expression(self.flowsheet().time, doc="Suspended solid concentration")
+        def TSS(blk, t):
+            return 0.75 * (
+                blk.inlet.conc_mass_comp[t, "X_I"]
+                + blk.inlet.conc_mass_comp[t, "X_P"]
+                + blk.inlet.conc_mass_comp[t, "X_BH"]
+                + blk.inlet.conc_mass_comp[t, "X_BA"]
+                + blk.inlet.conc_mass_comp[t, "X_S"]
+            )
+
+        @self.Expression(self.flowsheet().time, doc="Dewatering factor")
+        def f_dewat(blk, t):
+            return blk.p_dewat * (10 / (blk.TSS[t]))
+
+        @self.Expression(self.flowsheet().time, doc="Remove factor")
+        def f_q_du(blk, t):
+            return blk.TSS_rem / (pyunits.kg / pyunits.m**3) / 100 / blk.f_dewat[t]
+
+        self.non_particulate_components = Set(
+            initialize=[
+                "S_I",
+                "S_S",
+                "S_O",
+                "S_NO",
+                "S_NH",
+                "S_ND",
+                "H2O",
+                "S_ALK",
+            ]
+        )
+
+        self.particulate_components = Set(
+            initialize=["X_I", "X_S", "X_P", "X_BH", "X_BA", "X_ND"]
+        )
+
+        @self.Constraint(
+            self.flowsheet().time,
+            self.particulate_components,
+            doc="particulate fraction",
+        )
+        def overflow_particulate_fraction(blk, t, i):
+            return blk.split_fraction[t, "overflow", i] == 1 - blk.TSS_rem
+
+        @self.Constraint(
+            self.flowsheet().time,
+            self.non_particulate_components,
+            doc="soluble fraction",
+        )
+        def non_particulate_components(blk, t, i):
+            return blk.split_fraction[t, "overflow", i] == 1 - blk.f_q_du[t]
+
+    def _get_performance_contents(self, time_point=0):
+        var_dict = {}
+        for k in self.split_fraction.keys():
+            if k[0] == time_point:
+                var_dict[f"Split Fraction [{str(k[1:])}]"] = self.split_fraction[k]
+        return {"vars": var_dict}
+
+    def _get_stream_table_contents(self, time_point=0):
+        outlet_list = self.create_outlet_list()
+
+        io_dict = {}
+        if self.config.mixed_state_block is None:
+            io_dict["Inlet"] = self.mixed_state
+        else:
+            io_dict["Inlet"] = self.config.mixed_state_block
+
+        for o in outlet_list:
+            io_dict[o] = getattr(self, o + "_state")
+
+        return create_stream_table_dataframe(io_dict, time_point=time_point)