from pyomo.environ import (
NegativeReals,
Set,
Var,
)
from idaes.core import (
declare_process_block_class,
FlowDirection,
)
from idaes.core.util import scaling as iscale
from idaes.core.util.exceptions import ConfigurationError
from idaes.core.util.misc import add_object_reference
from idaes.core.base.control_volume1d import ControlVolume1DBlockData
import idaes.logger as idaeslog
from .MD_channel_base import (
MDChannelMixin,
PressureChangeType,
)
__author__ = "Elmira Shamlou"
[docs]@declare_process_block_class("MDChannel1DBlock")
class MDChannel1DBlockData(MDChannelMixin, ControlVolume1DBlockData):
def _skip_element(self, x):
if self.config.transformation_scheme != "FORWARD":
return x == self.length_domain.first()
else:
return x == self.length_domain.last()
[docs] def add_geometry(
self, length_var, width_var, flow_direction=FlowDirection.forward, **kwargs
):
"""
Method to create spatial domain and volume Var in ControlVolume.
Args:
length_var - An 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 - An 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
length_domain - (optional) a ContinuousSet to use as the length
domain for the ControlVolume. If not provided, a
new ContinuousSet will be created (default=None).
ContinuousSet should be normalized to run between
0 and 1.
length_domain_set - (optional) list of point to use to initialize
a new ContinuousSet if length_domain is not
provided (default = [0.0, 1.0]).
Returns:
None
"""
super().add_geometry(
length_var=length_var, flow_direction=flow_direction, **kwargs
)
add_object_reference(self, "width", width_var)
[docs] def add_state_blocks(
self,
has_phase_equilibrium=None,
property_package_vapor=None,
property_package_args_vapor=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)
self._add_interface_stateblock(has_phase_equilibrium)
self._add_vapor_stateblock(
property_package_vapor,
property_package_args_vapor,
has_phase_equilibrium=False,
)
def _add_pressure_change(self, pressure_change_type=PressureChangeType.calculated):
add_object_reference(self, "dP_dx", self.deltaP)
units_meta = self.config.property_package.get_metadata().get_derived_units
self.deltaP_channel = Var(
self.flowsheet().config.time,
initialize=-1e5,
bounds=(-1e6, 0),
domain=NegativeReals,
units=units_meta("pressure"),
doc="total prossure drop across the channel",
)
def _add_deltaP(self, pressure_change_type=PressureChangeType.calculated):
if pressure_change_type == PressureChangeType.fixed_per_stage:
@self.Constraint(
self.flowsheet().config.time,
self.length_domain,
doc="pressure change due to friction",
)
def eq_pressure_change(b, t, x):
return b.deltaP_channel[t] == b.dP_dx[t, x] * b.length
else:
@self.Constraint(
self.flowsheet().config.time, doc="Total Pressure drop across channel"
)
def eq_pressure_change(b, t):
return b.deltaP_channel[t] == sum(
b.dP_dx[t, x] * b.length / b.nfe for x in b.difference_elements
)
[docs] def initialize(
self,
state_args=None,
outlvl=idaeslog.NOTSET,
optarg=None,
solver=None,
hold_state=True,
initialize_guess=None,
type=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
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")
state_args = self._get_state_args(initialize_guess, state_args)
state_args_properties_in = state_args["inlet"]
source_flags = super().initialize(
state_args=state_args_properties_in,
outlvl=outlvl,
optarg=optarg,
solver=solver,
hold_state=True,
)
# Differentiate between hot and cold channels for properties_out
if type == "hot_ch":
state_args_properties_out = state_args["hot_outlet"]
elif type == "cold_ch":
state_args_properties_out = state_args["cold_outlet"]
else:
raise ConfigurationError(
"Either hot_ch or cold_ch must be set in the configuration."
)
state_args_interface = self._get_state_args_interface(
state_args_properties_in, state_args_properties_out
)
self.properties_interface.initialize(
outlvl=outlvl,
optarg=optarg,
solver=solver,
state_args=state_args_interface,
)
state_args_vapor = self._get_state_args_vapor(
state_args_properties_in, state_args_properties_out
)
self.properties_vapor.initialize(
outlvl=outlvl,
optarg=optarg,
solver=solver,
state_args=state_args_vapor,
)
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, "deltaP_channel"):
for v in self.deltaP_channel.values():
if iscale.get_scaling_factor(v) is None:
iscale.set_scaling_factor(v, 1e-4)
if hasattr(self, "dP_dx"):
for v in self.pressure_dx.values():
iscale.set_scaling_factor(v, 1e-5)