##############################################################################
# Institute for the Design of Advanced Energy Systems Process Systems
# Engineering Framework (IDAES PSE Framework) Copyright (c) 2018-2019, 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.txt and LICENSE.txt for full copyright and
# license information, respectively. Both files are also available online
# at the URL "https://github.com/IDAES/idaes-pse".
##############################################################################
"""
Example property package for the saponification of Ethyl Acetate with NaOH
Assumes dilute solutions with properties of H2O.
"""
# Import Python libraries
import logging
# Import Pyomo libraries
from pyomo.environ import (Constraint,
NonNegativeReals,
Param,
PositiveReals,
Reals,
Set,
value,
Var)
from pyomo.opt import SolverFactory
# Import IDAES cores
from idaes.core import (declare_process_block_class,
MaterialFlowBasis,
PhysicalParameterBlock,
StateBlockData,
StateBlock,
MaterialBalanceType,
EnergyBalanceType)
from idaes.core.util.model_statistics import degrees_of_freedom
from idaes.core.util.initialization import fix_state_vars, revert_state_vars
# Some more inforation about this module
__author__ = "Andrew Lee"
# Set up logger
_log = logging.getLogger(__name__)
[docs]@declare_process_block_class("SaponificationParameterBlock")
class PhysicalParameterData(PhysicalParameterBlock):
"""
Property Parameter Block Class
Contains parameters and indexing sets associated with properties for
superheated steam.
"""
[docs] def build(self):
'''
Callable method for Block construction.
'''
super(PhysicalParameterData, self).build()
self.state_block_class = SaponificationStateBlock
# List of valid phases in property package
self.phase_list = Set(initialize=['Liq'])
# Component list - a list of component identifiers
self.component_list = Set(initialize=['H2O', 'NaOH',
'EthylAcetate',
'SodiumAcetate',
'Ethanol'])
# Heat capacity of water
self.cp_mol = Param(mutable=False,
initialize=75.327,
doc="Molar heat capacity of water [J/mol.K]")
# Density of water
self.dens_mol = Param(mutable=False,
initialize=55388.0,
doc="Molar density of water [mol/m^3]")
# Thermodynamic reference state
self.pressure_ref = Param(within=PositiveReals,
mutable=True,
default=101325.0,
doc='Reference pressure [Pa]')
self.temperature_ref = Param(within=PositiveReals,
mutable=True,
default=298.15,
doc='Reference temperature [K]')
class _StateBlock(StateBlock):
"""
This Class contains methods which should be applied to Property Blocks as a
whole, rather than individual elements of indexed Property Blocks.
"""
def initialize(blk, state_args={}, state_vars_fixed=False,
hold_state=False, outlvl=0,
solver='ipopt', optarg={'tol': 1e-8}):
'''
Initialization routine for property package.
Keyword Arguments:
state_args : Dictionary with initial guesses for the state vars
chosen. Note that if this method is triggered
through the control volume, and if initial guesses
were not provied at the unit model level, the
control volume passes the inlet values as initial
guess.The keys for the state_args dictionary are:
flow_mol_comp : value at which to initialize component
flows (default=None)
pressure : value at which to initialize pressure
(default=None)
temperature : value at which to initialize temperature
(default=None)
outlvl : sets output level of initialization routine
* 0 = no output (default)
* 1 = return solver state for each step in routine
* 2 = include solver output infomation (tee=True)
state_vars_fixed: Flag to denote if state vars have already been
fixed.
- True - states have already been fixed by the
control volume 1D. Control volume 0D
does not fix the state vars, so will
be False if this state block is used
with 0D blocks.
- False - states have not been fixed. The state
block will deal with fixing/unfixing.
optarg : solver options dictionary object (default=None)
solver : str indicating whcih solver to use during
initialization (default = 'ipopt')
hold_state : flag indicating whether the initialization routine
should unfix any state variables fixed during
initialization (default=False).
- True - states varaibles are not unfixed, and
a dict of returned containing flags for
which states were fixed during
initialization.
- False - state variables are unfixed after
initialization by calling the
relase_state method
Returns:
If hold_states is True, returns a dict containing flags for
which states were fixed during initialization.
'''
# Deactivate the constraints specific for outlet block i.e.
# when defined state is False
# This is needed as fixing state vars fixes conc_mol_comp["H2O"],
# which is also specified by the conc_water_eqn constraint
for k in blk.keys():
if blk[k].config.defined_state is False:
blk[k].conc_water_eqn.deactivate()
if state_vars_fixed is False:
# Fix state variables if not already fixed
flags = fix_state_vars(blk, state_args)
else:
# Check when the state vars are fixed already result in dof 0
for k in blk.keys():
if degrees_of_freedom(blk[k]) != 0:
raise Exception("State vars fixed but degrees of freedom "
"for state block is not zero during "
"initialization.")
# Reactivate conc_water_eqn
for k in blk.keys():
if not blk[k].config.defined_state:
blk[k].conc_water_eqn.activate()
if state_vars_fixed is False:
if hold_state is True:
return flags
else:
blk.release_state(flags)
if outlvl > 0:
_log.info('{} Initialization Complete.'.format(blk.name))
def release_state(blk, flags, outlvl=0):
'''
Method to relase state variables fixed during initialization.
Keyword Arguments:
flags : dict containing information of which state variables
were fixed during initialization, and should now be
unfixed. This dict is returned by initialize if
hold_state=True.
outlvl : sets output level of of logging
'''
if flags is None:
return
# Unfix state variables
revert_state_vars(blk, flags)
if outlvl > 0:
if outlvl > 0:
_log.info('{} State Released.'.format(blk.name))
[docs]@declare_process_block_class("SaponificationStateBlock",
block_class=_StateBlock)
class SaponificationStateBlockData(StateBlockData):
"""
An example property package for properties for saponification of ethyl
acetate
"""
[docs] def build(self):
"""
Callable method for Block construction
"""
super(SaponificationStateBlockData, self).build()
# Create state variables
self.flow_vol = Var(initialize=1.0,
domain=NonNegativeReals,
doc='Total volumentric flowrate [m^3/s]')
self.pressure = Var(domain=Reals,
initialize=101325.0,
bounds=(1e3, 1e6),
doc='State pressure [Pa]')
self.temperature = Var(domain=Reals,
initialize=298.15,
bounds=(298.15, 323.15),
doc='State temperature [K]')
self.conc_mol_comp = Var(self._params.component_list,
domain=NonNegativeReals,
initialize=100.0,
doc='Component molar concentrations '
'[mol/m^3]')
if self.config.defined_state is False:
self.conc_water_eqn = Constraint(expr=self.conc_mol_comp["H2O"] ==
self._params.dens_mol)
[docs] def get_material_flow_terms(b, p, j):
return b.flow_vol*b.conc_mol_comp[j]
[docs] def get_enthalpy_flow_terms(b, p):
return (b.flow_vol*b._params.dens_mol*b._params.cp_mol *
(b.temperature - b._params.temperature_ref))
[docs] def get_material_density_terms(b, p, j):
return b.conc_mol_comp[j]
[docs] def get_energy_density_terms(b, p):
return b._params.dens_mol*b._params.cp_mol*(
b.temperature - b._params.temperature_ref)
def default_material_balance_type(self):
return MaterialBalanceType.componentPhase
def default_energy_balance_type(self):
return EnergyBalanceType.enthalpyTotal
[docs] def define_state_vars(b):
return {"flow_vol": b.flow_vol,
"conc_mol_comp": b.conc_mol_comp,
"temperature": b.temperature,
"pressure": b.pressure}
[docs] def define_display_vars(b):
return {"Volumetric Flowrate": b.flow_vol,
"Molar Concentration": b.conc_mol_comp,
"Temperature": b.temperature,
"Pressure": b.pressure}
[docs] def get_material_flow_basis(b):
return MaterialFlowBasis.molar
[docs] def model_check(blk):
"""
Model checks for property block
"""
# Check temperature bounds
if value(blk.temperature) < blk.temperature.lb:
_log.error('{} Temperature set below lower bound.'
.format(blk.name))
if value(blk.temperature) > blk.temperature.ub:
_log.error('{} Temperature set above upper bound.'
.format(blk.name))
# Check pressure bounds
if value(blk.pressure) < blk.pressure.lb:
_log.error('{} Pressure set below lower bound.'.format(blk.name))
if value(blk.pressure) > blk.pressure.ub:
_log.error('{} Pressure set above upper bound.'.format(blk.name))