add steam heater and condenser

watertap/costing/unit_models/heat_exchanger.py

@@ -28,12 +28,20 @@ def build_heat_exchanger_cost_param_block(blk):
         units=pyo.units.dimensionless,
     )
 
+    blk.steam_cost = pyo.Var(
+        initialize=0.008,
+        units=pyo.units.USD_2018 / (pyo.units.kg),
+        doc="steam cost per kg",
+    )
+
+    blk.parent_block().register_flow_type("steam", blk.steam_cost)
+
 
 @register_costing_parameter_block(
     build_rule=build_heat_exchanger_cost_param_block,
     parameter_block_name="heat_exchanger",
 )
-def cost_heat_exchanger(blk):
+def cost_heat_exchanger(blk, cost_steam_flow=False):
     """
     Heat Exchanger Costing Method
 
@@ -54,3 +62,12 @@ def cost_heat_exchanger(blk):
             to_units=blk.costing_package.base_currency,
         )
     )
+
+    if cost_steam_flow:
+        blk.costing_package.cost_flow(
+            pyo.units.convert(
+                (blk.unit_model.hot_side_inlet.flow_mass_phase_comp[0, "Vap", "H2O"]),
+                to_units=pyo.units.kg / pyo.units.s,
+            ),
+            "steam",
+        )

watertap/unit_models/steam_heater.py

@@ -0,0 +1,116 @@
+#################################################################################
+# WaterTAP Copyright (c) 2020-2024, 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/"
+#################################################################################
+
+from pyomo.environ import Var
+
+from idaes.core import (
+    declare_process_block_class,
+)
+from idaes.models.unit_models.heat_exchanger import HeatExchangerData
+from idaes.core.solvers import get_solver
+from idaes.core.util.model_statistics import degrees_of_freedom
+import idaes.logger as idaeslog
+
+
+_log = idaeslog.getLogger(__name__)
+
+
+__author__ = "Elmira Shamlou"
+
+
+@declare_process_block_class(
+    "FWHCondensing0D",
+    doc="""Feedwater Heater Condensing Section
+The feedwater heater condensing section model is a normal 0D heat exchanger
+model with an added constraint to calculate the steam flow such that the outlet
+of shell is a saturated liquid.""",
+)
+class FWHCondensing0DData(HeatExchangerData):
+    config = HeatExchangerData.CONFIG()
+
+    def build(self):
+        super().build()
+
+        @self.Constraint(
+            self.flowsheet().time,
+            self.hot_side.config.property_package.component_list,
+            doc="Mass balance",
+        )
+        def outlet_liquid_mass_balance(b, t, j):
+            b.hot_side.properties_out[t].flow_mass_phase_comp["Vap", j].fix(0)
+            return (
+                b.hot_side.properties_in[t].flow_mass_phase_comp["Vap", j]
+                + b.hot_side.properties_in[t].flow_mass_phase_comp["Liq", j]
+                == b.hot_side.properties_out[t].flow_mass_phase_comp["Liq", j]
+            )
+
+        units_meta = (
+            self.config.hot_side.property_package.get_metadata().get_derived_units
+        )
+
+        self.pressure_diff = Var(
+            self.flowsheet().time, initialize=0, units=units_meta("pressure")
+        )
+
+        self.pressure_diff.fix()
+
+        @self.Constraint(self.flowsheet().time, doc="Saturation pressure constraint")
+        def outlet_pressure_sat(b, t):
+            return (
+                b.hot_side.properties_out[t].pressure + b.pressure_diff[t]
+                == b.hot_side.properties_out[t].pressure_sat
+            )
+
+    def initialize_build(self, *args, **kwargs):
+        """
+        Use the regular heat exchanger initialization, with the extraction rate
+        constraint deactivated; then it activates the constraint and calculates
+        a steam inlet flow rate.
+        """
+        solver = kwargs.get("solver", None)
+        optarg = kwargs.get("oparg", {})
+        outlvl = kwargs.get("outlvl", idaeslog.NOTSET)
+        init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
+        solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit")
+
+        self.outlet_liquid_mass_balance.deactivate()
+        self.outlet_pressure_sat.deactivate()
+        self.hot_side_inlet.fix()
+        self.cold_side_inlet.fix()
+        self.hot_side_outlet.unfix()
+        self.cold_side_outlet.unfix()
+        self.cold_side_outlet.flow_mass_phase_comp[0, "Vap", "H2O"].fix()
+
+        # Do regular heat exchanger initialization
+        super().initialize_build(*args, **kwargs)
+        self.outlet_liquid_mass_balance.activate()
+        self.outlet_pressure_sat.activate()
+
+        for j in self.hot_side.config.property_package.component_list:
+            self.hot_side_inlet.flow_mass_phase_comp[0, "Vap", j].unfix()
+
+        if degrees_of_freedom(self) != 0:
+            raise Exception(
+                f"{self.name} degrees of freedom were not 0 at the beginning "
+                f"of initialization. DoF = {degrees_of_freedom(self)}"
+            )
+
+        # Create solver
+        opt = get_solver(solver, optarg)
+
+        with idaeslog.solver_log(solve_log, idaeslog.DEBUG) as slc:
+            res = opt.solve(self, tee=slc.tee)
+        init_log.info(
+            "Initialization Complete (w/ extraction calc): {}".format(
+                idaeslog.condition(res)
+            )
+        )

watertap/unit_models/tests/test_steam_heater.py

@@ -0,0 +1,75 @@
+#################################################################################
+# WaterTAP Copyright (c) 2020-2024, 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/"
+#################################################################################
+
+import pytest
+from pyomo.environ import (
+    ConcreteModel,
+    value,
+)
+
+from idaes.core import FlowsheetBlock
+import watertap.property_models.water_prop_pack as props_w
+from watertap.unit_models.steam_heater import FWHCondensing0D
+from idaes.core.util.model_statistics import degrees_of_freedom
+from idaes.core.solvers import get_solver
+from watertap.unit_models.mvc.components.lmtd_chen_callback import (
+    delta_temperature_chen_callback,
+)
+from idaes.models.unit_models.heat_exchanger import (
+    HeatExchangerFlowPattern,
+)
+
+# Set up solver
+solver = get_solver()
+
+
+@pytest.mark.unit
+def test_unit_model():
+    m = ConcreteModel()
+    m.fs = FlowsheetBlock(dynamic=False)
+    m.fs.default_property_package = props_w.WaterParameterBlock()
+
+    m.fs.unit = FWHCondensing0D(
+        hot_side_name="hot",
+        cold_side_name="cold",
+        hot={
+            "property_package": m.fs.default_property_package,
+            "has_pressure_change": False,
+        },
+        cold={
+            "property_package": m.fs.default_property_package,
+            "has_pressure_change": False,
+        },
+        delta_temperature_callback=delta_temperature_chen_callback,
+        flow_pattern=HeatExchangerFlowPattern.countercurrent,
+    )
+
+    m.fs.unit.hot_side_inlet.flow_mass_phase_comp[0, "Vap", "H2O"].set_value(6)
+    m.fs.unit.hot_side_inlet.flow_mass_phase_comp[0, "Liq", "H2O"].fix(0)
+    m.fs.unit.hot_side_inlet.temperature.fix(273.15 + 140)
+    m.fs.unit.cold_side_inlet.pressure.fix(101325)
+    m.fs.unit.cold_side_inlet.temperature.fix(273.15 + 70)
+    m.fs.unit.cold_side_inlet.flow_mass_phase_comp[0, "Vap", "H2O"].fix(0)
+    m.fs.unit.cold_side_outlet.flow_mass_phase_comp[0, "Vap", "H2O"].fix(0)
+    m.fs.unit.cold_side_inlet.flow_mass_phase_comp[0, "Liq", "H2O"].fix(6)
+    m.fs.unit.area.fix(50)
+    m.fs.unit.overall_heat_transfer_coefficient.fix(2e3)
+
+    assert degrees_of_freedom(m) == 0
+
+    m.fs.unit.initialize()
+
+    # assert degrees_of_freedom(m) == 0
+
+    assert pytest.approx(0.687041189050, rel=1e-5) == value(
+        m.fs.unit.hot_side_inlet.flow_mass_phase_comp[0, "Vap", "H2O"]
+    )