###############################################################################
# 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/"
#
###############################################################################
from pyomo.environ import (
NonNegativeReals,
NegativeReals,
Param,
Set,
Var,
value,
units as pyunits,
)
from idaes.core import (
declare_process_block_class,
EnergyBalanceType,
FlowDirection,
)
from idaes.core.util import scaling as iscale
from idaes.core.util.misc import add_object_reference
from idaes.core.util.exceptions import BalanceTypeNotSupportedError
from idaes.core.base.control_volume0d import ControlVolume0DBlockData
import idaes.logger as idaeslog
from watertap.core.membrane_channel_base import (
MembraneChannelMixin,
PressureChangeType,
CONFIG_Template,
)
[docs]@declare_process_block_class("MembraneChannel0DBlock")
class MembraneChannel0DBlockData(MembraneChannelMixin, ControlVolume0DBlockData):
def _skip_element(self, x):
return False
# overwrite CV0D `add_geometry`
[docs] def add_geometry(
self, length_var=None, width_var=None, flow_direction=FlowDirection.forward
):
"""
Method to create spatial domain and volume Var in ControlVolume.
Args:
length_var - (optional) external variable to use for the length of
the channel. If a variable is provided, a
reference will be made to this in place of the length
Var.
width_var - (optional) external variable to use for the width of
the channel. If a variable is provided, a
reference will be made to this in place of the length
Var.
flow_direction - argument indicating direction of material flow
relative to length domain. Valid values:
- FlowDirection.forward (default), flow goes
from 0 to 1.
- FlowDirection.backward, flow goes from 1 to 0
Returns:
None
"""
# Validate and create flow direction attribute, like 1D
if flow_direction in (flwd for flwd in FlowDirection):
self._flow_direction = flow_direction
else:
raise ConfigurationError(
"{} invalid value for flow_direction "
"argument. Must be a FlowDirection Enum.".format(self.name)
)
self._add_var_reference(length_var, "length", "length_var")
self._add_var_reference(width_var, "width", "width_var")
[docs] def add_state_blocks(self, has_phase_equilibrium=None):
"""
This method constructs the state blocks for the
control volume.
Args:
has_phase_equilibrium: indicates whether equilibrium calculations
will be required in state blocks
Returns:
None
"""
super().add_state_blocks(has_phase_equilibrium=has_phase_equilibrium)
# quack like a 1D model
self.length_domain = Set(ordered=True, initialize=(0.0, 1.0))
add_object_reference(self, "difference_elements", self.length_domain)
self._set_nfe()
if self._flow_direction == FlowDirection.forward:
add_object_reference(
self,
"properties",
{
**{
(t, 0.0): self.properties_in[t]
for t in self.flowsheet().config.time
},
**{
(t, 1.0): self.properties_out[t]
for t in self.flowsheet().config.time
},
},
)
else:
add_object_reference(
self,
"properties",
{
**{
(t, 0.0): self.properties_out[t]
for t in self.flowsheet().config.time
},
**{
(t, 1.0): self.properties_in[t]
for t in self.flowsheet().config.time
},
},
)
self._add_interface_stateblock(has_phase_equilibrium)
def apply_transformation(self):
pass
def _add_pressure_change(self, pressure_change_type=PressureChangeType.calculated):
if pressure_change_type == PressureChangeType.fixed_per_stage:
return
units_meta = self.config.property_package.get_metadata().get_derived_units
if pressure_change_type == PressureChangeType.fixed_per_unit_length:
# Pressure change equation when dP/dx = user-specified constant,
self.dP_dx = Var(
self.flowsheet().config.time,
initialize=-5e4,
bounds=(-2e5, -1e3),
domain=NegativeReals,
units=units_meta("pressure") * units_meta("length") ** -1,
doc="pressure drop per unit length across channel",
)
@self.Constraint(
self.flowsheet().config.time, doc="pressure change due to friction"
)
def eq_pressure_change(b, t):
return b.deltaP[t] == b.dP_dx[t] * b.length
elif pressure_change_type == PressureChangeType.calculated:
self.dP_dx = Var(
self.flowsheet().config.time,
self.length_domain,
initialize=-5e4,
bounds=(-2e5, -1e3),
domain=NegativeReals,
units=units_meta("pressure") * units_meta("length") ** -1,
doc="Pressure drop per unit length of channel at inlet and outlet",
)
@self.Constraint(
self.flowsheet().config.time, doc="Total Pressure drop across channel"
)
def eq_pressure_change(b, t):
return b.deltaP[t] == sum(
b.dP_dx[t, x] * b.length / b.nfe for x in b.length_domain
)
else:
raise ConfigurationError(
f"Unrecognized pressure_change_type {pressure_change_type}"
)
[docs] def initialize(
self,
state_args=None,
outlvl=idaeslog.NOTSET,
optarg=None,
solver=None,
hold_state=True,
initialize_guess=None,
):
"""
Initialization routine for the membrane channel control volume
Keyword Arguments:
state_args : a dict of arguments to be passed to the property
package(s) to provide an initial state for
initialization (see documentation of the specific
property package) (default = {}).
outlvl : sets output log level of initialization routine
optarg : solver options dictionary object (default=None, use
default solver options)
solver : str indicating which solver to use during
initialization (default = None)
hold_state : flag indicating whether the initialization routine
should unfix any state variables fixed during
initialization, **default** - True. **Valid values:**
**True** - states variables 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 release_state
method.
initialize_guess : a dict of guesses for solvent_recovery, solute_recovery,
and cp_modulus. These guesses offset the initial values
for the retentate, permeate, and membrane interface
state blocks from the inlet feed
(default =
{'deltaP': -1e4,
'solvent_recovery': 0.5,
'solute_recovery': 0.01,
'cp_modulus': 1.1})
Returns:
If hold_states is True, returns a dict containing flags for which
states were fixed during initialization.
"""
# Get inlet state if not provided
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="control_volume")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="control_volume")
# TODO: this function needs to be changed for use on the permeate side
state_args = self._get_state_args(initialize_guess, state_args)
# intialize self.properties
source_flags = self.properties_in.initialize(
state_args=state_args["feed_side"],
outlvl=outlvl,
optarg=optarg,
solver=solver,
hold_state=True,
)
self.properties_out.initialize(
state_args=state_args["retentate"],
outlvl=outlvl,
optarg=optarg,
solver=solver,
)
self.properties_interface.initialize(
outlvl=outlvl,
optarg=optarg,
solver=solver,
state_args=state_args["interface"],
)
init_log.info("Initialization Complete")
if hold_state:
return source_flags
else:
self.release_state(source_flags, outlvl)
def calculate_scaling_factors(self):
super().calculate_scaling_factors()
if hasattr(self, "area"):
if iscale.get_scaling_factor(self.area) is None:
iscale.set_scaling_factor(self.area, 100)
if hasattr(self, "dP_dx"):
for v in self.dP_dx.values():
if iscale.get_scaling_factor(v) is None:
iscale.set_scaling_factor(v, 1e-4)