###############################################################################
# ProteusLib 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/nawi-hub/proteuslib/"
#
###############################################################################
# Import Pyomo libraries
from pyomo.common.config import ConfigBlock, ConfigValue, In
from pyomo.environ import (Block,
Var,
Suffix,
NonNegativeReals,
Reals,
value,
units as pyunits)
# Import IDAES cores
import idaes.logger as idaeslog
from idaes.core import (ControlVolume0DBlock,
declare_process_block_class,
MaterialBalanceType,
EnergyBalanceType,
MomentumBalanceType,
UnitModelBlockData,
useDefault)
from idaes.core.util import get_solver
from idaes.core.util.config import is_physical_parameter_block
from idaes.core.util.exceptions import ConfigurationError
from idaes.core.util.initialization import revert_state_vars
from idaes.core.util.tables import create_stream_table_dataframe
import idaes.core.util.scaling as iscale
_log = idaeslog.getLogger(__name__)
[docs]@declare_process_block_class("PressureExchanger")
class PressureExchangerData(UnitModelBlockData):
"""
Standard Pressure Exchanger Unit Model Class:
- steady state only
"""
CONFIG = ConfigBlock()
CONFIG.declare("dynamic", ConfigValue(
domain=In([False]),
default=False,
description="Dynamic model flag - must be False",
doc="""Indicates whether this model will be dynamic or not,
**default** = False. Pressure exchangers do not support dynamic behavior."""))
CONFIG.declare("has_holdup", ConfigValue(
default=False,
domain=In([False]),
description="Holdup construction flag - must be False",
doc="""Indicates whether holdup terms should be constructed or not.
**default** - False. Pressure exchangers do not have defined volume, thus
this must be False."""))
CONFIG.declare("material_balance_type", ConfigValue(
default=MaterialBalanceType.useDefault,
domain=In(MaterialBalanceType),
description="Material balance construction flag",
doc="""Indicates what type of mass balance should be constructed,
**default** - MaterialBalanceType.useDefault.
**Valid values:** {
**MaterialBalanceType.useDefault - refer to property package for default
balance type
**MaterialBalanceType.none** - exclude material balances,
**MaterialBalanceType.componentPhase** - use phase component balances,
**MaterialBalanceType.componentTotal** - use total component balances,
**MaterialBalanceType.elementTotal** - use total element balances,
**MaterialBalanceType.total** - use total material balance.}"""))
CONFIG.declare("energy_balance_type", ConfigValue(
default=EnergyBalanceType.useDefault,
domain=In(EnergyBalanceType),
description="Energy balance construction flag",
doc="""Indicates what type of energy balance should be constructed,
**default** - EnergyBalanceType.useDefault.
**Valid values:** {
**EnergyBalanceType.useDefault - refer to property package for default
balance type
**EnergyBalanceType.none** - exclude energy balances,
**EnergyBalanceType.enthalpyTotal** - single enthalpy balance for material,
**EnergyBalanceType.enthalpyPhase** - enthalpy balances for each phase,
**EnergyBalanceType.energyTotal** - single energy balance for material,
**EnergyBalanceType.energyPhase** - energy balances for each phase.}"""))
CONFIG.declare("momentum_balance_type", ConfigValue(
default=MomentumBalanceType.pressureTotal,
domain=In(MomentumBalanceType),
description="Momentum balance construction flag",
doc="""Indicates what type of momentum balance should be constructed,
**default** - MomentumBalanceType.pressureTotal.
**Valid values:** {
**MomentumBalanceType.none** - exclude momentum balances,
**MomentumBalanceType.pressureTotal** - single pressure balance for material,
**MomentumBalanceType.pressurePhase** - pressure balances for each phase,
**MomentumBalanceType.momentumTotal** - single momentum balance for material,
**MomentumBalanceType.momentumPhase** - momentum balances for each phase.}"""))
CONFIG.declare("property_package", ConfigValue(
default=useDefault,
domain=is_physical_parameter_block,
description="Property package to use for control volume",
doc="""Property parameter object used to define property calculations,
**default** - useDefault.
**Valid values:** {
**useDefault** - use default package from parent model or flowsheet,
**PhysicalParameterObject** - a PhysicalParameterBlock object.}"""))
CONFIG.declare("property_package_args", ConfigBlock(
implicit=True,
description="Arguments to use for constructing property packages",
doc="""A ConfigBlock with arguments to be passed to a property block(s)
and used when constructing these,
**default** - None.
**Valid values:** {
see property package for documentation.}"""))
[docs] def build(self):
super().build()
# Pressure exchanger supports only liquid phase
if self.config.property_package.phase_list != ['Liq']:
raise ConfigurationError(
"Pressure exchanger model only supports one liquid phase ['Liq'],"
"the property package has specified the following phases {}"
.format(self.config.property_package.phase_list))
self.scaling_factor = Suffix(direction=Suffix.EXPORT)
units_meta = self.config.property_package.get_metadata().get_derived_units
self.efficiency_pressure_exchanger = Var(
self.flowsheet().config.time,
initialize=0.95,
bounds=(1e-6, 1),
domain=NonNegativeReals,
units=pyunits.dimensionless,
doc='Pressure exchanger efficiency')
# Build control volume for high pressure side
self.high_pressure_side = ControlVolume0DBlock(default={
"dynamic": False,
"has_holdup": False,
"property_package": self.config.property_package,
"property_package_args": self.config.property_package_args})
self.high_pressure_side.add_state_blocks(
has_phase_equilibrium=False)
self.high_pressure_side.add_material_balances(
balance_type=self.config.material_balance_type)
self.high_pressure_side.add_momentum_balances(
balance_type=self.config.momentum_balance_type,
has_pressure_change=True)
self.high_pressure_side.deltaP.setub(0)
@self.high_pressure_side.Expression(
self.flowsheet().config.time,
doc='Work transferred to high pressure side fluid (should be negative)')
def work(b, t):
return b.properties_in[t].flow_vol * b.deltaP[t]
# Build control volume for low pressure side
self.low_pressure_side = ControlVolume0DBlock(default={
"dynamic": False,
"has_holdup": False,
"property_package": self.config.property_package,
"property_package_args": self.config.property_package_args})
self.low_pressure_side.add_state_blocks(
has_phase_equilibrium=False)
self.low_pressure_side.add_material_balances(
balance_type=self.config.material_balance_type)
self.low_pressure_side.add_momentum_balances(
balance_type=self.config.momentum_balance_type,
has_pressure_change=True)
self.low_pressure_side.deltaP.setlb(0)
@self.low_pressure_side.Expression(
self.flowsheet().config.time,
doc='Work transferred to low pressure side fluid')
def work(b, t):
return b.properties_in[t].flow_vol * b.deltaP[t]
# Add Ports
self.add_inlet_port(name='high_pressure_inlet', block=self.high_pressure_side)
self.add_outlet_port(name='high_pressure_outlet', block=self.high_pressure_side)
self.add_inlet_port(name='low_pressure_inlet', block=self.low_pressure_side)
self.add_outlet_port(name='low_pressure_outlet', block=self.low_pressure_side)
# Performance equations
@self.Constraint(
self.flowsheet().config.time,
doc="Pressure transfer")
def eq_pressure_transfer(b, t):
return (b.low_pressure_side.deltaP[t] ==
b.efficiency_pressure_exchanger[t] * -b.high_pressure_side.deltaP[t])
@self.Constraint(
self.flowsheet().config.time,
doc="Equal volumetric flow rate")
def eq_equal_flow_vol(b, t):
return (b.high_pressure_side.properties_in[t].flow_vol ==
b.low_pressure_side.properties_in[t].flow_vol)
@self.Constraint(
self.flowsheet().config.time,
doc="Equal low pressure on both sides")
def eq_equal_low_pressure(b, t):
return (b.high_pressure_side.properties_out[t].pressure ==
b.low_pressure_side.properties_in[t].pressure)
@self.low_pressure_side.Constraint(
self.flowsheet().config.time,
doc="Isothermal constraint")
def eq_isothermal_temperature(b, t):
return b.properties_in[t].temperature == b.properties_out[t].temperature
@self.high_pressure_side.Constraint(
self.flowsheet().config.time,
doc="Isothermal constraint")
def eq_isothermal_temperature(b, t):
return b.properties_in[t].temperature == b.properties_out[t].temperature
[docs] def initialize(
self,
state_args=None,
routine=None,
outlvl=idaeslog.NOTSET,
solver=None,
optarg=None):
"""
General wrapper for pressure exchanger initialization routine
Keyword Arguments:
routine : str stating which initialization routine to execute
* None - currently no specialized routine for Pressure exchanger unit
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 level of initialization routine (default=idaeslog.NOTSET)
optarg : solver options dictionary object, if None provided an empty
dictionary will be used (default=None)
solver : solver object or string indicating which solver to use during
initialization, if None provided the default solver will be used
(default = None)
Returns: None
"""
# Get loggers
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="properties")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="properties")
# Set solver and options
opt = get_solver(solver, optarg)
# initialize inlets
flags_low_in = self.low_pressure_side.properties_in.initialize(
outlvl=outlvl,
optarg=optarg,
solver=solver,
state_args=state_args,
hold_state=True)
flags_high_in = self.high_pressure_side.properties_in.initialize(
outlvl=outlvl,
optarg=optarg,
solver=solver,
state_args=state_args,
hold_state=True)
init_log.info_high("Initialize inlets complete")
# check that inlets are feasible
if (value(self.low_pressure_side.properties_in[0].pressure)
> value(self.high_pressure_side.properties_in[0].pressure)):
raise ConfigurationError(
"Initializing pressure exchanger failed because "
"the low pressure side inlet has a higher pressure "
"than the high pressure side inlet")
if (abs(value(self.low_pressure_side.properties_in[0].flow_vol)
- value(self.high_pressure_side.properties_in[0].flow_vol))
/ value(self.high_pressure_side.properties_in[0].flow_vol)
> 1e-4): # flow_vol values are not within 0.1%
raise ConfigurationError(
"Initializing pressure exchanger failed because "
"the volumetric flow rates are not equal for both inlets")
else: # volumetric flow is equal, deactivate flow constraint for the solve
self.eq_equal_flow_vol.deactivate()
# initialize outlets from inlets and update pressure
def propogate_state(sb1, sb2):
state_dict_1 = sb1.define_state_vars()
state_dict_2 = sb2.define_state_vars()
for k in state_dict_1.keys():
if state_dict_1[k].is_indexed():
for m in state_dict_1[k].keys():
state_dict_2[k][m].value = state_dict_1[k][m].value
else:
state_dict_2[k].value = state_dict_1[k].value
# low pressure side
propogate_state(self.low_pressure_side.properties_in[0],
self.low_pressure_side.properties_out[0])
self.low_pressure_side.properties_out[0].pressure = (
self.low_pressure_side.properties_in[0].pressure.value
+ self.efficiency_pressure_exchanger[0].value
* (self.high_pressure_side.properties_in[0].pressure.value
- self.low_pressure_side.properties_in[0].pressure.value))
# high pressure side
propogate_state(self.high_pressure_side.properties_in[0],
self.high_pressure_side.properties_out[0])
self.high_pressure_side.properties_out[0].pressure.value = \
self.low_pressure_side.properties_in[0].pressure.value
init_log.info_high("Initialize outlets complete")
# Solve unit
with idaeslog.solver_log(solve_log, idaeslog.DEBUG) as slc:
res = opt.solve(self, tee=slc.tee)
init_log.info("Initialization complete: {}".format(idaeslog.condition(res)))
# release state of fixed variables
self.low_pressure_side.properties_in.release_state(flags_low_in)
self.high_pressure_side.properties_in.release_state(flags_high_in)
# reactivate volumetric flow constraint
self.eq_equal_flow_vol.activate()
def get_costing(self, module=None):
self.costing = Block()
module.PressureExchanger_costing(self.costing)
def calculate_scaling_factors(self):
super().calculate_scaling_factors()
# scale variables
if iscale.get_scaling_factor(self.efficiency_pressure_exchanger) is None:
# efficiency should always be between 0.1-1
iscale.set_scaling_factor(self.efficiency_pressure_exchanger, 1)
# scale expressions
if iscale.get_scaling_factor(self.low_pressure_side.work) is None:
sf = iscale.get_scaling_factor(self.low_pressure_side.properties_in[0].flow_vol)
sf = sf * iscale.get_scaling_factor(self.low_pressure_side.deltaP[0])
iscale.set_scaling_factor(self.low_pressure_side.work, sf)
if iscale.get_scaling_factor(self.high_pressure_side.work) is None:
sf = iscale.get_scaling_factor(self.high_pressure_side.properties_in[0].flow_vol)
sf = sf * iscale.get_scaling_factor(self.high_pressure_side.deltaP[0])
iscale.set_scaling_factor(self.high_pressure_side.work, sf)
# transform constraints
for t, c in self.low_pressure_side.eq_isothermal_temperature.items():
sf = iscale.get_scaling_factor(self.low_pressure_side.properties_in[t].temperature)
iscale.constraint_scaling_transform(c, sf)
for t, c in self.high_pressure_side.eq_isothermal_temperature.items():
sf = iscale.get_scaling_factor(self.high_pressure_side.properties_in[t].temperature)
iscale.constraint_scaling_transform(c, sf)
for t, c in self.eq_pressure_transfer.items():
sf = iscale.get_scaling_factor(self.low_pressure_side.deltaP[t])
iscale.constraint_scaling_transform(c, sf)
for t, c in self.eq_equal_flow_vol.items():
sf = iscale.get_scaling_factor(self.low_pressure_side.properties_in[t].flow_vol)
iscale.constraint_scaling_transform(c, sf)
for t, c in self.eq_equal_low_pressure.items():
sf = iscale.get_scaling_factor(self.low_pressure_side.properties_in[t].pressure)
iscale.constraint_scaling_transform(c, sf)
def _get_stream_table_contents(self, time_point=0):
return create_stream_table_dataframe(
{
"HP Side In" : self.high_pressure_inlet,
"HP Side Out" : self.high_pressure_outlet,
"LP Side In" : self.low_pressure_inlet,
"LP Side Out" : self.low_pressure_outlet,
},
time_point=time_point)
def _get_performance_contents(self, time_point=0):
t = time_point
return { "vars" : { "Efficiency" : self.efficiency_pressure_exchanger[t],
"HP Side Pressure Change" : self.high_pressure_side.deltaP[t],
"LP Side Pressure Change" : self.low_pressure_side.deltaP[t],
},
"exprs" : {
"HP Side Mechanical Work" : self.high_pressure_side.work[t],
"LP Side Mechanical Work" : self.low_pressure_side.work[t],
},
"params" : {
},
}