Source code for idaes.models_extra.power_generation.unit_models.soec_design

#################################################################################
# The Institute for the Design of Advanced Energy Systems Integrated Platform
# Framework (IDAES IP) was produced under the DOE Institute for the
# Design of Advanced Energy Systems (IDAES).
#
# Copyright (c) 2018-2023 by the software owners: The Regents of the
# University of California, through Lawrence Berkeley National Laboratory,
# National Technology & Engineering Solutions of Sandia, LLC, Carnegie Mellon
# University, West Virginia University Research Corporation, et al.
# All rights reserved.  Please see the files COPYRIGHT.md and LICENSE.md
# for full copyright and license information.
#################################################################################
# TODO: Missing doc strings
# pylint: disable=missing-module-docstring

__author__ = "John Eslick"

import pyomo.environ as pyo
from pyomo.network import Arc
from pyomo.common.config import ConfigBlock, ConfigValue, In, Bool

import idaes.core.util.constants as iconst
from idaes.core import UnitModelBlockData, declare_process_block_class
from idaes.core.util.config import is_physical_parameter_block
from idaes.models.properties.modular_properties.base.generic_property import (
    GenericParameterBlock,
)
from idaes.models.properties.modular_properties.base.generic_reaction import (
    GenericReactionParameterBlock,
)
import idaes.models.unit_models as um  # um = unit models
from idaes.core.util.initialization import propagate_state
import idaes.core.util.scaling as iscale
from idaes.core.solvers import get_solver
from idaes.models_extra.power_generation.properties.natural_gas_PR import (
    get_prop,
    get_rxn,
    EosType,
)
from idaes.core.util.exceptions import ConfigurationError, InitializationError
import idaes.logger as idaeslog
from idaes.core.util import from_json, to_json, StoreSpec


[docs]@declare_process_block_class("SoecDesign", doc="Simple SOEC model for process design.") class SoecDesignData(UnitModelBlockData): """Simple 0D SOEC model. This model can be used to develop a flowsheet at the design point or for the basis of a surrogate. For off-design applications, a more detailed model is required.""" CONFIG = UnitModelBlockData.CONFIG(implicit=True) CONFIG.declare( "oxygen_side_property_package", ConfigValue( domain=is_physical_parameter_block, description="Property package for the oxygen side.", doc=( "Property package for the oxygen side, using " "idaes.models_extra.power_generation.properties.natural_gas_PR is " "strongly recommended, either Peng-Robinson or Ideal is okay" ), ), ) CONFIG.declare( "hydrogen_side_property_package", ConfigValue( domain=is_physical_parameter_block, description="Property package for the hydrogen side.", doc=( "Property package for the hydrogen side, using " "idaes.models_extra.power_generation.properties.natural_gas_PR is " "strongly recommended, either Peng-Robinson or Ideal is okay" ), ), ) CONFIG.declare( "oxygen_side_property_package_args", ConfigBlock( implicit=True, description="Property package arguments for the oxygen side.", doc="Property package arguments for the oxygen side.", ), ) CONFIG.declare( "hydrogen_side_property_package_args", ConfigBlock( implicit=True, description="Property package arguments for the hydrogen side.", doc="Property package arguments for the hydrogen side.", ), ) CONFIG.declare( "reaction_eos", ConfigValue( default=EosType.PR, domain=In(EosType), description="Physical properties for electrolysis reactions", doc=( "Reaction properties equation of state in: " "{EosType.PR, EosType.IDEAL}." ), ), ) CONFIG.declare( "has_heat_transfer", ConfigValue( default=False, domain=Bool, description="Heat transfer term construction flag", doc="Indicates whether the SOEC is adiabatic. Default=False (adiabatic)", ), )
[docs] def build(self): """Construct a unit model data block""" super().build() # Do a little validation. # The hydrogen side needs water and hydrogen if set(self.config.hydrogen_side_property_package.component_list) != { "H2", "H2O", }: raise ConfigurationError( "SOEC hydrogen side must contain exactly H2 and H2O" ) # The oxygen side must have oxygen in it. if not "O2" in self.config.oxygen_side_property_package.component_list: raise ConfigurationError("SOEC oxygen side must contain O2") # build the block, use smaller methods to make it easier to follow self._add_electrolysis_properties() self._add_unit_models() self._add_arcs() self._add_variables() self._add_constraints() self._add_o2_translator_constraints() self._add_h2_inlet_translator_constraints() self._add_h2_outlet_translator_constraints() self._add_ports() self._scaling_guess()
def _add_electrolysis_properties(self): """Add the electrolysis property package. This has H2, H2O and O2, and is only used internally by the unit for the electrolysis reaction. """ self.electrolysis_prop_params = GenericParameterBlock( **get_prop( {"H2O", "H2", "O2"}, phases={"Vap"}, eos=self.config.reaction_eos ), doc="Physical property parameters for the electrolysis reaction", ) # Electrolysis is just the hydrogen combustion reaction backward self.electrolysis_rxn_params = GenericReactionParameterBlock( **get_rxn(self.electrolysis_prop_params, {"h2_cmb"}), doc="Reaction parameters", ) def _add_unit_models(self): """Add the unit models that make up the composite model. The main things happening are 1) Electrolysis Reaction, 2) O2 Separation, 3) O2 mixes with sweep gas, and 4) sweep gas heat transfer. There are translator blocks to switch between property package depending on the existence of components in various streams. """ self.h2_inlet_translator = um.Translator( doc="Translate hydrogen side properties to electrolysis properties", inlet_property_package=self.config.hydrogen_side_property_package, inlet_property_package_args=self.config.hydrogen_side_property_package_args, outlet_property_package=self.electrolysis_prop_params, outlet_state_defined=False, ) self.electrolysis_reactor = um.StoichiometricReactor( doc="Electrolysis reactor", property_package=self.electrolysis_prop_params, reaction_package=self.electrolysis_rxn_params, has_pressure_change=False, has_heat_transfer=True, ) self.o2_separator = um.Separator( property_package=self.electrolysis_prop_params, split_basis=um.SplittingType.componentFlow, outlet_list=["h2_strm", "o2_strm"], ) self.h2_outlet_translator = um.Translator( doc="Translate electrolysis properties to hydrogen properties", inlet_property_package=self.electrolysis_prop_params, outlet_property_package=self.config.hydrogen_side_property_package, outlet_property_package_args=self.config.hydrogen_side_property_package_args, outlet_state_defined=False, ) self.o2_translator = um.Translator( doc="Translate electrolysis properties to oxygen properties", inlet_property_package=self.electrolysis_prop_params, outlet_property_package=self.config.oxygen_side_property_package, outlet_property_package_args=self.config.oxygen_side_property_package_args, outlet_state_defined=False, ) self.o2_mixer = um.Mixer( property_package=self.config.oxygen_side_property_package, property_package_args=self.config.oxygen_side_property_package_args, momentum_mixing_type=um.MomentumMixingType.none, inlet_list=["sweep_strm", "o2_strm"], ) self.sweep_heater = um.Heater( property_package=self.config.oxygen_side_property_package, property_package_args=self.config.oxygen_side_property_package_args, ) def _add_arcs(self): """Add streams to connect internal units.""" self.strm1 = Arc( doc="Hydrogen side inlet to electrolysis translator", source=self.h2_inlet_translator.outlet, destination=self.electrolysis_reactor.inlet, ) self.strm2 = Arc( doc="Electrolysis reactor to oxygen separation", source=self.electrolysis_reactor.outlet, destination=self.o2_separator.inlet, ) self.strm3 = Arc( doc="Oxygen separation to hydrogen side outlet translator", source=self.o2_separator.h2_strm, destination=self.h2_outlet_translator.inlet, ) self.strm4 = Arc( doc="Oxygen from electrolysis to translator to sweep properties", source=self.o2_separator.o2_strm, destination=self.o2_translator.inlet, ) self.strm5 = Arc( doc="Oxygen translator to O2/sweep mixer", source=self.o2_translator.outlet, destination=self.o2_mixer.o2_strm, ) self.strm6 = Arc( doc="O2/sweep mixer to sweep heater", source=self.o2_mixer.outlet, destination=self.sweep_heater.inlet, ) # Probably don't need this and may need to call it again for dynamic # models, but this will make it easy for a user to have a flowsheet # with one steady state model in it. pyo.TransformationFactory("network.expand_arcs").apply_to(self) def _add_variables(self): """Add variables for unit model level constraints""" self.current = pyo.Var( self.flowsheet().time, initialize=0, units=pyo.units.ampere, doc="SOEC module electric current", ) self.water_utilization = pyo.Var( self.flowsheet().time, units=pyo.units.dimensionless, doc="Fraction of water used in electrolysis reaction", ) self.cell_potential = pyo.Var( self.flowsheet().time, initialize=1.3, units=pyo.units.volts, doc="Electric potential for a single cell", ) self.heat = pyo.Var( self.flowsheet().time, units=pyo.units.W, initialize=0, doc="Heat transferred to the module", ) self.hydrogen_side_outlet_temperature = pyo.Reference( self.electrolysis_reactor.control_volume.properties_out[:].temperature ) self.oxygen_side_outlet_temperature = pyo.Reference( self.sweep_heater.control_volume.properties_out[:].temperature ) def _add_constraints(self): """Add unit model constraints""" @self.Constraint(self.flowsheet().time) def water_utilization_eqn(b, t): return b.electrolysis_reactor.control_volume.properties_out[ t ].flow_mol_comp[ "H2O" ] == b.electrolysis_reactor.control_volume.properties_in[ t ].flow_mol_comp[ "H2O" ] * ( 1.0 - b.water_utilization[t] ) @self.Expression(self.flowsheet().time) def current_expr(b, t): return ( ( ( b.electrolysis_reactor.control_volume.properties_in[ t ].mole_frac_comp["H2O"] * b.electrolysis_reactor.control_volume.properties_in[ t ].flow_mol ) - ( b.electrolysis_reactor.control_volume.properties_out[ t ].mole_frac_comp["H2O"] * b.electrolysis_reactor.control_volume.properties_out[ t ].flow_mol ) ) * 2 * iconst.Constants.faraday_constant ) @self.Constraint(self.flowsheet().time) def current_eqn(b, t): return b.current[t] == b.current_expr[t] # Fix the O2 separator split fractions to just remove O2 from fuel side self.o2_separator.split_fraction[:, "o2_strm", "O2"].fix(1) self.o2_separator.split_fraction[:, "o2_strm", "H2O"].fix(0) self.o2_separator.split_fraction[:, "o2_strm", "H2"].fix(0) @self.o2_mixer.Constraint(self.flowsheet().time) def pressure_eqn(b, t): return b.mixed_state[t].pressure == b.sweep_strm_state[t].pressure if not self.config.has_heat_transfer: @self.Constraint(self.flowsheet().time) def heat_transfer_eqn(b, t): return b.heat[t] == 0 @self.Expression(self.flowsheet().time) def delta_enth(b, t): return ( b.o2_separator.h2_strm_state[t].get_enthalpy_flow_terms("Vap") + b.sweep_heater.control_volume.properties_out[ t ].get_enthalpy_flow_terms("Vap") - b.electrolysis_reactor.control_volume.properties_in[ t ].get_enthalpy_flow_terms("Vap") - b.o2_mixer.sweep_strm_state[t].get_enthalpy_flow_terms("Vap") + b.heat[t] ) @self.Constraint(self.flowsheet().time) def cell_potential_eqn(b, t): return b.cell_potential[t] == b.delta_enth[t] / b.current[t] @staticmethod def _translator_ftp_constraints(translator): """Generalize some translator block constraints""" @translator.Constraint(translator.flowsheet().time) def temperature_eqn(b, t): return b.properties_out[t].temperature == b.properties_in[t].temperature @translator.Constraint(translator.flowsheet().time) def flow_mol_eqn(b, t): return b.properties_out[t].flow_mol == b.properties_in[t].flow_mol @translator.Constraint(translator.flowsheet().time) def pressure_eqn(b, t): return b.properties_out[t].pressure == b.properties_in[t].pressure def _add_o2_translator_constraints(self): """Add constraints to translate from electrolysis properties to sweep properties. The stream being translated contains only O2. """ t0 = self.flowsheet().time.first() comps = set(self.o2_translator.properties_out[t0].mole_frac_comp.keys()) comps.remove("O2") @self.o2_translator.Constraint(self.flowsheet().time, comps) def mole_frac_comp_eqn(b, t, c): return b.properties_out[t].mole_frac_comp[c] == 1e-19 self.o2_translator.properties_out[:].mole_frac_comp["O2"] = 1 self._translator_ftp_constraints(self.o2_translator) def _add_h2_inlet_translator_constraints(self): """Translate the inlet hydrogen stream to electrolysis properties. This stream contains only H2 and H2O. """ t0 = self.flowsheet().time.first() # There is no O2. So set the value to zero. Don't need a constraint # for this due to the sum = 1 constraint self.o2_translator.properties_out[:].mole_frac_comp["O2"] = 1e-19 # Add constraints for the other components comps = set(self.h2_inlet_translator.properties_in[t0].mole_frac_comp.keys()) @self.h2_inlet_translator.Constraint(self.flowsheet().time, comps) def mole_frac_comp_eqn(b, t, c): return ( b.properties_out[t].mole_frac_comp[c] == b.properties_in[t].mole_frac_comp[c] ) self._translator_ftp_constraints(self.h2_inlet_translator) def _add_h2_outlet_translator_constraints(self): """Translate the electrolysis properties to hydrogen side properties. This stream contains only H2 and H2O. """ t0 = self.flowsheet().time.first() # Add constraints for the other components comps = set(self.h2_outlet_translator.properties_out[t0].mole_frac_comp.keys()) comps.remove("H2") # Need to remove one component due to sum = 1 constraint @self.h2_outlet_translator.Constraint(self.flowsheet().time, comps) def mole_frac_comp_eqn(b, t, c): return ( b.properties_out[t].mole_frac_comp[c] == b.properties_in[t].mole_frac_comp[c] ) self._translator_ftp_constraints(self.h2_outlet_translator) def _add_ports(self): """Add unit level ports""" self.add_inlet_port( name="hydrogen_side_inlet", block=self.h2_inlet_translator.properties_in, doc="Hydrogen side inlet port", ) self.add_inlet_port( name="oxygen_side_inlet", block=self.o2_mixer.sweep_strm_state, doc="Oxygen side inlet port", ) self.add_outlet_port( name="hydrogen_side_outlet", block=self.h2_outlet_translator.properties_out, doc="Hydrogen side outlet port", ) self.add_outlet_port( name="oxygen_side_outlet", block=self.sweep_heater.control_volume.properties_out, doc="Oxygen side outlet port", )
[docs] def set_flow_scale(self, scale=1): """Set default flow scaling in the property packages based on the expected magnitude of typical flows Args: scale (float): Expected molar flow variable scale Returns: None """ self.config.oxygen_side_property_package.set_default_scaling("flow_mol", scale) self.config.hydrogen_side_property_package.set_default_scaling( "flow_mol", scale ) self.electrolysis_prop_params.set_default_scaling("flow_mol", scale) self.config.oxygen_side_property_package.set_default_scaling( "flow_mol_phase", scale ) self.config.hydrogen_side_property_package.set_default_scaling( "flow_mol_phase", scale ) self.electrolysis_prop_params.set_default_scaling("flow_mol_phase", scale) for v in self.electrolysis_reactor.control_volume.rate_reaction_extent.values(): iscale.set_scaling_factor(v, scale) for ( v ) in self.electrolysis_reactor.control_volume.rate_reaction_generation.values(): iscale.set_scaling_factor(v, scale)
[docs] def set_heat_scale(self, scale=1e-5): """Set the heat transfer scale factor roughly based on the size of the process. Args: scale (float): Expected heat transfer scale Returns: None """ iscale.set_scaling_factor(self.electrolysis_reactor.control_volume.heat, scale) iscale.set_scaling_factor(self.sweep_heater.control_volume.heat, scale) iscale.set_scaling_factor(self.heat, scale)
[docs] def set_current_scale(self, scale=1e-6): """Set the expected electrical current scale Args: scale (float): Expected electrical current scale Returns: None """ iscale.set_scaling_factor(self.current, scale)
def _scaling_guess(self): self.set_flow_scale() self.set_heat_scale() self.set_current_scale() # For components that exist we don't expect particularly low # concentrations, so change the default to 10, which should be good # for mole fractions > 0.01 which is what we expect here. self.config.oxygen_side_property_package.set_default_scaling( "mole_frac_comp", 10 ) self.config.hydrogen_side_property_package.set_default_scaling( "mole_frac_comp", 10 ) self.electrolysis_prop_params.set_default_scaling("mole_frac_comp", 10) self.config.oxygen_side_property_package.set_default_scaling( "mole_frac_phase_comp", 10 ) self.config.hydrogen_side_property_package.set_default_scaling( "mole_frac_phase_comp", 10 ) self.electrolysis_prop_params.set_default_scaling("mole_frac_phase_comp", 10) # Set some other scale factors that we have a good guess for unt = self.electrolysis_reactor iscale.set_scaling_factor( unt.control_volume.properties_in[0.0].enth_mol_phase["Vap"], 1e-4 ) iscale.set_scaling_factor( unt.control_volume.properties_out[0.0].enth_mol_phase["Vap"], 1e-4 ) unt = self.o2_separator iscale.set_scaling_factor(unt.h2_strm_state[0.0].enth_mol_phase["Vap"], 1e-4) unt = self.o2_mixer iscale.set_scaling_factor(unt.o2_strm_state[0.0].enth_mol_phase["Vap"], 1e-4) iscale.set_scaling_factor(unt.o2_strm_state[0.0].enth_mol_phase["Vap"], 1e-4) iscale.set_scaling_factor(unt.mixed_state[0.0].enth_mol_phase["Vap"], 1e-4) iscale.set_scaling_factor(unt.sweep_strm_state[0.0].enth_mol_phase["Vap"], 1e-4) unt = self.sweep_heater iscale.set_scaling_factor( unt.control_volume.properties_in[0.0].enth_mol_phase["Vap"], 1e-4 ) iscale.set_scaling_factor( unt.control_volume.properties_out[0.0].enth_mol_phase["Vap"], 1e-4 )
[docs] def calculate_scaling_factors(self): """Calculate scale factors for the unit model equations""" for t in self.flowsheet().time: iscale.constraint_scaling_transform( self.water_utilization_eqn[t], iscale.get_scaling_factor( self.electrolysis_reactor.control_volume.properties_in[t].flow_mol ), ) iscale.constraint_scaling_transform( self.current_eqn[t], iscale.get_scaling_factor(self.current[t]) ) iscale.constraint_scaling_transform( self.o2_mixer.pressure_eqn[t], iscale.get_scaling_factor(self.o2_mixer.mixed_state[t].pressure), ) iscale.constraint_scaling_transform( self.o2_translator.pressure_eqn[t], iscale.get_scaling_factor(self.o2_translator.properties_in[t].pressure), ) iscale.constraint_scaling_transform( self.o2_translator.temperature_eqn[t], iscale.get_scaling_factor( self.o2_translator.properties_in[t].temperature ), ) iscale.constraint_scaling_transform( self.o2_translator.temperature_eqn[t], iscale.get_scaling_factor( self.o2_translator.properties_in[t].temperature ), ) iscale.constraint_scaling_transform( self.o2_translator.flow_mol_eqn[t], iscale.get_scaling_factor(self.o2_translator.properties_in[t].flow_mol), ) iscale.constraint_scaling_transform( self.h2_inlet_translator.pressure_eqn[t], iscale.get_scaling_factor( self.h2_inlet_translator.properties_in[t].pressure ), ) iscale.constraint_scaling_transform( self.h2_inlet_translator.temperature_eqn[t], iscale.get_scaling_factor( self.h2_inlet_translator.properties_in[t].temperature ), ) iscale.constraint_scaling_transform( self.h2_inlet_translator.flow_mol_eqn[t], iscale.get_scaling_factor( self.h2_inlet_translator.properties_in[t].flow_mol ), ) iscale.constraint_scaling_transform( self.h2_outlet_translator.pressure_eqn[t], iscale.get_scaling_factor( self.h2_outlet_translator.properties_in[t].pressure ), ) iscale.constraint_scaling_transform( self.h2_outlet_translator.temperature_eqn[t], iscale.get_scaling_factor( self.h2_outlet_translator.properties_in[t].temperature ), ) iscale.constraint_scaling_transform( self.h2_outlet_translator.flow_mol_eqn[t], iscale.get_scaling_factor( self.h2_outlet_translator.properties_in[t].flow_mol ), ) iscale.constraint_scaling_transform(self.cell_potential_eqn[t], 1) if not self.config.has_heat_transfer: iscale.constraint_scaling_transform( self.heat_transfer_eqn[t], iscale.get_scaling_factor(self.heat[t]) ) for (t, i), c in self.o2_translator.mole_frac_comp_eqn.items(): iscale.constraint_scaling_transform( c, iscale.get_scaling_factor( self.o2_translator.properties_out[t].mole_frac_comp[i] ), ) for (t, i), c in self.h2_inlet_translator.mole_frac_comp_eqn.items(): iscale.constraint_scaling_transform( c, iscale.get_scaling_factor( self.h2_inlet_translator.properties_out[t].mole_frac_comp[i] ), ) for (t, i), c in self.h2_outlet_translator.mole_frac_comp_eqn.items(): iscale.constraint_scaling_transform( c, iscale.get_scaling_factor( self.h2_outlet_translator.properties_out[t].mole_frac_comp[i] ), )
[docs] def initialize_build( self, outlvl=idaeslog.NOTSET, solver=None, optarg=None, ): init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit") solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit") init_log.info_high("SOEC Initialization Starting") solver_obj = get_solver(solver, optarg) sp = StoreSpec.value_isfixed_isactive(only_fixed=True) istate = to_json(self, return_dict=True, wts=sp) self.oxygen_side_inlet.fix() self.hydrogen_side_inlet.fix() self.oxygen_side_outlet.unfix() self.hydrogen_side_outlet.unfix() self.h2_inlet_translator.initialize(outlvl=outlvl, solver=solver, optarg=optarg) propagate_state(self.strm1) self.electrolysis_reactor.initialize( outlvl=outlvl, solver=solver, optarg=optarg ) propagate_state(self.strm2) self.o2_separator.initialize(outlvl=outlvl, solver=solver, optarg=optarg) propagate_state(self.strm3) self.h2_outlet_translator.initialize( outlvl=outlvl, solver=solver, optarg=optarg ) propagate_state(self.strm4) self.o2_translator.initialize(outlvl=outlvl, solver=solver, optarg=optarg) propagate_state(self.strm5) self.o2_mixer.initialize(outlvl=outlvl, solver=solver, optarg=optarg) propagate_state(self.strm6) self.sweep_heater.initialize(outlvl=outlvl, solver=solver, optarg=optarg) for t in self.current.keys(): self.current[t] = pyo.value(self.current_expr[t]) with idaeslog.solver_log(solve_log, idaeslog.DEBUG) as slc: res = solver_obj.solve(self, tee=slc.tee) if not pyo.check_optimal_termination(res): raise InitializationError("SOEC failed to initialize.") from_json(self, sd=istate, wts=sp) init_log.info_high("SOEC Initialization Complete")