def test_config():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = props.NaClParameterBlock()
m.fs.unit = ReverseOsmosis0D(default={"property_package": m.fs.properties})
assert len(m.fs.unit.config) == 12
assert not m.fs.unit.config.dynamic
assert not m.fs.unit.config.has_holdup
assert m.fs.unit.config.material_balance_type == \
MaterialBalanceType.useDefault
assert m.fs.unit.config.energy_balance_type == \
EnergyBalanceType.useDefault
assert m.fs.unit.config.momentum_balance_type == \
MomentumBalanceType.pressureTotal
assert not m.fs.unit.config.has_pressure_change
assert m.fs.unit.config.property_package is \
m.fs.properties
assert m.fs.unit.config.concentration_polarization_type == \
ConcentrationPolarizationType.calculated
assert m.fs.unit.config.mass_transfer_coefficient == \
MassTransferCoefficient.calculated
assert m.fs.unit.config.pressure_change_type == \
PressureChangeType.fixed_per_stage
def test_option_pressure_change_calculated():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = props.NaClParameterBlock()
m.fs.unit = ReverseOsmosis0D(default={
"property_package": m.fs.properties,
"has_pressure_change": True,
"concentration_polarization_type": ConcentrationPolarizationType.none,
"mass_transfer_coefficient": MassTransferCoefficient.none,
"pressure_change_type": PressureChangeType.calculated})
assert m.fs.unit.config.concentration_polarization_type == \
ConcentrationPolarizationType.none
assert m.fs.unit.config.mass_transfer_coefficient == \
MassTransferCoefficient.none
assert m.fs.unit.config.pressure_change_type == \
PressureChangeType.calculated
assert isinstance(m.fs.unit.feed_side.deltaP, Var)
assert isinstance(m.fs.unit.deltaP, Var)
assert isinstance(m.fs.unit.channel_height, Var)
assert isinstance(m.fs.unit.width, Var)
assert isinstance(m.fs.unit.length, Var)
assert isinstance(m.fs.unit.dh, Var)
assert isinstance(m.fs.unit.spacer_porosity, Var)
assert isinstance(m.fs.unit.N_Re, Var)
def test_option_has_pressure_change():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = props.NaClParameterBlock()
m.fs.unit = ReverseOsmosis0D(default={
"property_package": m.fs.properties,
"has_pressure_change": True})
assert isinstance(m.fs.unit.feed_side.deltaP, Var)
assert isinstance(m.fs.unit.deltaP, Var)
def test_option_concentration_polarization_type_fixed():
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = props.NaClParameterBlock()
m.fs.unit = ReverseOsmosis0D(default={
"property_package": m.fs.properties,
"has_pressure_change": True,
"concentration_polarization_type": ConcentrationPolarizationType.fixed,
"mass_transfer_coefficient": MassTransferCoefficient.none})
assert m.fs.unit.config.concentration_polarization_type == \
ConcentrationPolarizationType.fixed
assert isinstance(m.fs.unit.cp_modulus, Var)
def RO_frame(self):
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = props.NaClParameterBlock()
m.fs.unit = ReverseOsmosis0D(
default={
"property_package": m.fs.properties,
"has_pressure_change": True,
"concentration_polarization_type":
ConcentrationPolarizationType.fixed,
"mass_transfer_coefficient": MassTransferCoefficient.none,
})
# fully specify system
feed_flow_mass = 1
feed_mass_frac_NaCl = 0.035
feed_pressure = 50e5
feed_temperature = 273.15 + 25
membrane_pressure_drop = 3e5
membrane_area = 50
A = 4.2e-12
B = 3.5e-8
pressure_atmospheric = 101325
concentration_polarization_modulus = 1.1
feed_mass_frac_H2O = 1 - feed_mass_frac_NaCl
m.fs.unit.inlet.flow_mass_phase_comp[0, "Liq", "NaCl"].fix(
feed_flow_mass * feed_mass_frac_NaCl)
m.fs.unit.inlet.flow_mass_phase_comp[0, "Liq", "H2O"].fix(
feed_flow_mass * feed_mass_frac_H2O)
m.fs.unit.inlet.pressure[0].fix(feed_pressure)
m.fs.unit.inlet.temperature[0].fix(feed_temperature)
m.fs.unit.deltaP.fix(-membrane_pressure_drop)
m.fs.unit.area.fix(membrane_area)
m.fs.unit.A_comp.fix(A)
m.fs.unit.B_comp.fix(B)
m.fs.unit.permeate.pressure[0].fix(pressure_atmospheric)
m.fs.unit.cp_modulus.fix(concentration_polarization_modulus)
return m
def NF_frame(self):
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = props.NaClParameterBlock()
m.fs.unit = NanoFiltration0D(default={
"property_package": m.fs.properties,
"has_pressure_change": True,
})
# fully specify system
feed_flow_mass = 1
feed_mass_frac_NaCl = 0.035
feed_pressure = 6e5
feed_temperature = 273.15 + 25
membrane_pressure_drop = 1e5
membrane_area = 50 * feed_flow_mass
A = 3.77e-11
B = 4.724e-5
sigma = 0.28
pressure_atmospheric = 101325
feed_mass_frac_H2O = 1 - feed_mass_frac_NaCl
m.fs.unit.inlet.flow_mass_phase_comp[0, "Liq", "NaCl"].fix(
feed_flow_mass * feed_mass_frac_NaCl)
m.fs.unit.inlet.flow_mass_phase_comp[0, "Liq", "H2O"].fix(
feed_flow_mass * feed_mass_frac_H2O)
m.fs.unit.inlet.pressure[0].fix(feed_pressure)
m.fs.unit.inlet.temperature[0].fix(feed_temperature)
m.fs.unit.deltaP.fix(-membrane_pressure_drop)
m.fs.unit.area.fix(membrane_area)
m.fs.unit.A_comp.fix(A)
m.fs.unit.B_comp.fix(B)
m.fs.unit.sigma.fix(sigma)
m.fs.unit.permeate.pressure[0].fix(pressure_atmospheric)
return m
def build(number_of_stages=2):
# ---building model---
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = props.NaClParameterBlock()
m.fs.costing = WaterTAPCosting()
m.fs.NumberOfStages = Param(initialize=number_of_stages)
m.fs.StageSet = RangeSet(m.fs.NumberOfStages)
m.fs.LSRRO_StageSet = RangeSet(2, m.fs.NumberOfStages)
m.fs.NonFinal_StageSet = RangeSet(m.fs.NumberOfStages-1)
m.fs.feed = Feed(default={'property_package': m.fs.properties})
m.fs.product = Product(default={'property_package': m.fs.properties})
m.fs.disposal = Product(default={'property_package': m.fs.properties})
# Add the mixers
m.fs.Mixers = Mixer(m.fs.NonFinal_StageSet, default={
"property_package": m.fs.properties,
"momentum_mixing_type": MomentumMixingType.equality, # booster pump will match pressure
"inlet_list": ['upstream', 'downstream']})
total_pump_work = 0
# Add the pumps
m.fs.PrimaryPumps = Pump(m.fs.StageSet, default={"property_package": m.fs.properties})
for pump in m.fs.PrimaryPumps.values():
pump.costing = UnitModelCostingBlock(default={
"flowsheet_costing_block":m.fs.costing})
m.fs.costing.cost_flow(pyunits.convert(pump.work_mechanical[0], to_units=pyunits.kW), "electricity")
# Add the equalizer pumps
m.fs.BoosterPumps = Pump(m.fs.LSRRO_StageSet, default={"property_package": m.fs.properties})
for pump in m.fs.BoosterPumps.values():
pump.costing = UnitModelCostingBlock(default={
"flowsheet_costing_block":m.fs.costing})
m.fs.costing.cost_flow(pyunits.convert(pump.work_mechanical[0], to_units=pyunits.kW), "electricity")
# Add the stages ROs
m.fs.ROUnits = ReverseOsmosis0D(m.fs.StageSet, default={
"property_package": m.fs.properties,
"has_pressure_change": True,
"pressure_change_type": PressureChangeType.calculated,
"mass_transfer_coefficient": MassTransferCoefficient.calculated,
"concentration_polarization_type": ConcentrationPolarizationType.calculated})
for ro_unit in m.fs.ROUnits.values():
ro_unit.costing = UnitModelCostingBlock(default={
"flowsheet_costing_block":m.fs.costing})
# Add EnergyRecoveryDevice
m.fs.EnergyRecoveryDevice = Pump(default={"property_package": m.fs.properties})
m.fs.EnergyRecoveryDevice.costing = UnitModelCostingBlock(default={
"flowsheet_costing_block":m.fs.costing,
"costing_method_arguments":{"pump_type":PumpType.energy_recovery_device}})
m.fs.costing.cost_flow(pyunits.convert(m.fs.EnergyRecoveryDevice.work_mechanical[0], to_units=pyunits.kW), "electricity")
# additional variables or expressions
# system water recovery
m.fs.water_recovery = Var(
initialize=0.5,
bounds=(0, 1),
domain=NonNegativeReals,
units=pyunits.dimensionless,
doc='System Water Recovery')
m.fs.eq_water_recovery = Constraint(expr=\
sum(m.fs.feed.flow_mass_phase_comp[0,'Liq',:]) * m.fs.water_recovery == \
sum(m.fs.product.flow_mass_phase_comp[0,'Liq',:]) )
# costing
m.fs.costing.cost_process()
product_flow_vol_total = m.fs.product.properties[0].flow_vol
m.fs.costing.add_LCOW(product_flow_vol_total)
m.fs.costing.add_specific_energy_consumption(product_flow_vol_total)
# objective
m.fs.objective = Objective(expr=m.fs.costing.LCOW)
# connections
# Connect the feed to the first pump
m.fs.feed_to_pump = Arc(source=m.fs.feed.outlet, destination=m.fs.PrimaryPumps[1].inlet)
# Connect the primary RO permeate to the product
m.fs.primary_RO_to_product = Arc(source=m.fs.ROUnits[1].permeate, destination=m.fs.product.inlet)
# Connect the Pump n to the Mixer n
m.fs.pump_to_mixer = Arc(m.fs.NonFinal_StageSet,
rule=lambda fs,n : {'source':fs.PrimaryPumps[n].outlet,
'destination':fs.Mixers[n].upstream})
# Connect the Mixer n to the Stage n
m.fs.mixer_to_stage = Arc(m.fs.NonFinal_StageSet,
rule=lambda fs,n : {'source':fs.Mixers[n].outlet,
'destination':fs.ROUnits[n].inlet})
# Connect the Stage n to the Pump n+1
m.fs.stage_to_pump = Arc(m.fs.NonFinal_StageSet,
rule=lambda fs,n : {'source':fs.ROUnits[n].retentate,
'destination':fs.PrimaryPumps[n+1].inlet})
# Connect the Stage n to the Eq Pump n
m.fs.stage_to_eq_pump = Arc(m.fs.LSRRO_StageSet,
rule=lambda fs,n : {'source':fs.ROUnits[n].permeate,
'destination':fs.BoosterPumps[n].inlet})
# Connect the Eq Pump n to the Mixer n-1
m.fs.eq_pump_to_mixer = Arc(m.fs.LSRRO_StageSet,
rule=lambda fs,n : {'source':fs.BoosterPumps[n].outlet,
'destination':fs.Mixers[n-1].downstream})
# Connect the Pump N to the Stage N
last_stage = m.fs.StageSet.last()
m.fs.pump_to_stage = Arc(source=m.fs.PrimaryPumps[last_stage].outlet,
destination=m.fs.ROUnits[last_stage].inlet)
# Connect Final Stage to EnergyRecoveryDevice Pump
m.fs.stage_to_erd = Arc(source=m.fs.ROUnits[last_stage].retentate,
destination=m.fs.EnergyRecoveryDevice.inlet)
# Connect the EnergyRecoveryDevice to the disposal
m.fs.erd_to_disposal = Arc(source=m.fs.EnergyRecoveryDevice.outlet,
destination=m.fs.disposal.inlet)
# additional bounding
for b in m.component_data_objects(Block, descend_into=True):
# NaCl solubility limit
if hasattr(b, 'mass_frac_phase_comp'):
b.mass_frac_phase_comp['Liq', 'NaCl'].setub(0.26)
TransformationFactory("network.expand_arcs").apply_to(m)
return m
def build():
# flowsheet set up
m = ConcreteModel()
m.fs = FlowsheetBlock(default={'dynamic': False})
m.fs.properties = props.NaClParameterBlock()
m.fs.costing = WaterTAPCosting()
# unit models
m.fs.feed = Feed(default={'property_package': m.fs.properties})
m.fs.S1 = Separator(default={
"property_package": m.fs.properties,
"outlet_list": ['P1', 'PXR']
})
m.fs.P1 = Pump(default={'property_package': m.fs.properties})
m.fs.PXR = PressureExchanger(default={'property_package': m.fs.properties})
m.fs.P2 = Pump(default={'property_package': m.fs.properties})
m.fs.M1 = Mixer(
default={
"property_package": m.fs.properties,
"momentum_mixing_type":
MomentumMixingType.equality, # booster pump will match pressure
"inlet_list": ['P1', 'P2']
})
m.fs.RO = ReverseOsmosis0D(
default={
"property_package":
m.fs.properties,
"has_pressure_change":
True,
"pressure_change_type":
PressureChangeType.calculated,
"mass_transfer_coefficient":
MassTransferCoefficient.calculated,
"concentration_polarization_type":
ConcentrationPolarizationType.calculated,
})
m.fs.product = Product(default={'property_package': m.fs.properties})
m.fs.disposal = Product(default={'property_package': m.fs.properties})
# costing
m.fs.costing.cost_flow(
pyunits.convert(m.fs.P1.work_mechanical[0], to_units=pyunits.kW),
"electricity")
m.fs.costing.cost_flow(
pyunits.convert(m.fs.P2.work_mechanical[0], to_units=pyunits.kW),
"electricity")
m.fs.P1.costing = UnitModelCostingBlock(
default={"flowsheet_costing_block": m.fs.costing})
m.fs.P2.costing = UnitModelCostingBlock(
default={"flowsheet_costing_block": m.fs.costing})
m.fs.RO.costing = UnitModelCostingBlock(
default={"flowsheet_costing_block": m.fs.costing})
m.fs.PXR.costing = UnitModelCostingBlock(
default={"flowsheet_costing_block": m.fs.costing})
m.fs.costing.cost_process()
m.fs.costing.add_LCOW(m.fs.product.properties[0].flow_vol)
m.fs.costing.add_specific_energy_consumption(
m.fs.product.properties[0].flow_vol)
# connections
m.fs.s01 = Arc(source=m.fs.feed.outlet, destination=m.fs.S1.inlet)
m.fs.s02 = Arc(source=m.fs.S1.P1, destination=m.fs.P1.inlet)
m.fs.s03 = Arc(source=m.fs.P1.outlet, destination=m.fs.M1.P1)
m.fs.s04 = Arc(source=m.fs.M1.outlet, destination=m.fs.RO.inlet)
m.fs.s05 = Arc(source=m.fs.RO.permeate, destination=m.fs.product.inlet)
m.fs.s06 = Arc(source=m.fs.RO.retentate,
destination=m.fs.PXR.high_pressure_inlet)
m.fs.s07 = Arc(source=m.fs.PXR.high_pressure_outlet,
destination=m.fs.disposal.inlet)
m.fs.s08 = Arc(source=m.fs.S1.PXR, destination=m.fs.PXR.low_pressure_inlet)
m.fs.s09 = Arc(source=m.fs.PXR.low_pressure_outlet,
destination=m.fs.P2.inlet)
m.fs.s10 = Arc(source=m.fs.P2.outlet, destination=m.fs.M1.P2)
TransformationFactory("network.expand_arcs").apply_to(m)
# scaling
# set default property values
m.fs.properties.set_default_scaling('flow_mass_phase_comp',
1,
index=('Liq', 'H2O'))
m.fs.properties.set_default_scaling('flow_mass_phase_comp',
1e2,
index=('Liq', 'NaCl'))
# set unit model values
iscale.set_scaling_factor(m.fs.P1.control_volume.work, 1e-3)
iscale.set_scaling_factor(m.fs.P2.control_volume.work, 1e-3)
iscale.set_scaling_factor(m.fs.PXR.low_pressure_side.work, 1e-3)
iscale.set_scaling_factor(m.fs.PXR.high_pressure_side.work, 1e-3)
# touch properties used in specifying and initializing the model
m.fs.feed.properties[0].flow_vol_phase['Liq']
m.fs.feed.properties[0].mass_frac_phase_comp['Liq', 'NaCl']
m.fs.S1.mixed_state[0].mass_frac_phase_comp
m.fs.S1.PXR_state[0].flow_vol_phase['Liq']
# unused scaling factors needed by IDAES base costing module
# calculate and propagate scaling factors
iscale.calculate_scaling_factors(m)
return m
def test_Pdrop_fixed_per_unit_length(self):
""" Testing 0D-RO with PressureChangeType.fixed_per_unit_length option.
"""
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = props.NaClParameterBlock()
m.fs.unit = ReverseOsmosis0D(default={
"property_package": m.fs.properties,
"has_pressure_change": True,
"concentration_polarization_type": ConcentrationPolarizationType.calculated,
"mass_transfer_coefficient": MassTransferCoefficient.calculated,
"pressure_change_type": PressureChangeType.fixed_per_unit_length})
# fully specify system
feed_flow_mass = 1
feed_mass_frac_NaCl = 0.035
feed_mass_frac_H2O = 1 - feed_mass_frac_NaCl
feed_pressure = 50e5
feed_temperature = 273.15 + 25
membrane_area = 50
length = 20
A = 4.2e-12
B = 3.5e-8
pressure_atmospheric = 101325
membrane_pressure_drop = 3e5
m.fs.unit.inlet.flow_mass_phase_comp[0, 'Liq', 'NaCl'].fix(
feed_flow_mass * feed_mass_frac_NaCl)
m.fs.unit.inlet.flow_mass_phase_comp[0, 'Liq', 'H2O'].fix(
feed_flow_mass * feed_mass_frac_H2O)
m.fs.unit.inlet.pressure[0].fix(feed_pressure)
m.fs.unit.inlet.temperature[0].fix(feed_temperature)
m.fs.unit.area.fix(membrane_area)
m.fs.unit.A_comp.fix(A)
m.fs.unit.B_comp.fix(B)
m.fs.unit.permeate.pressure[0].fix(pressure_atmospheric)
m.fs.unit.channel_height.fix(0.002)
m.fs.unit.spacer_porosity.fix(0.75)
m.fs.unit.length.fix(length)
m.fs.unit.dP_dx.fix(-membrane_pressure_drop / length)
# test statistics
assert number_variables(m) == 142
assert number_total_constraints(m) == 112
assert number_unused_variables(m) == 0
# test degrees of freedom
assert degrees_of_freedom(m) == 0
# test scaling
m.fs.properties.set_default_scaling('flow_mass_phase_comp', 1, index=('Liq', 'H2O'))
m.fs.properties.set_default_scaling('flow_mass_phase_comp', 1e2, index=('Liq', 'NaCl'))
calculate_scaling_factors(m)
# check that all variables have scaling factors.
# TODO: see aforementioned TODO on revisiting scaling and associated testing for property models.
unscaled_var_list = list(unscaled_variables_generator(m.fs.unit, include_fixed=True))
assert len(unscaled_var_list) == 0
# test initialization
initialization_tester(m, fail_on_warning=True)
# test variable scaling
badly_scaled_var_lst = list(badly_scaled_var_generator(m))
assert badly_scaled_var_lst == []
# test solve
results = solver.solve(m, tee=True)
# Check for optimal solution
assert_optimal_termination(results)
# test solution
assert (pytest.approx(-3.000e5, rel=1e-3) == value(m.fs.unit.deltaP[0]))
assert (pytest.approx(4.562e-3, rel=1e-3) ==
value(m.fs.unit.flux_mass_phase_comp_avg[0, 'Liq', 'H2O']))
assert (pytest.approx(1.593e-6, rel=1e-3) ==
value(m.fs.unit.flux_mass_phase_comp_avg[0, 'Liq', 'NaCl']))
assert (pytest.approx(0.2281, rel=1e-3) ==
value(m.fs.unit.mixed_permeate[0].flow_mass_phase_comp['Liq', 'H2O']))
assert (pytest.approx(7.963e-5, rel=1e-3) ==
value(m.fs.unit.mixed_permeate[0].flow_mass_phase_comp['Liq', 'NaCl']))
assert (pytest.approx(41.96, rel=1e-3) ==
value(m.fs.unit.feed_side.properties_interface[0,0.].conc_mass_phase_comp['Liq', 'NaCl']))
assert (pytest.approx(46.57, rel=1e-3) ==
value(m.fs.unit.feed_side.properties_out[0].conc_mass_phase_comp['Liq', 'NaCl']))
assert (pytest.approx(49.94, rel=1e-3) ==
value(m.fs.unit.feed_side.properties_interface[0, 1.].conc_mass_phase_comp['Liq', 'NaCl']))
def test_CP_calculation_with_kf_fixed(self):
""" Testing 0D-RO with ConcentrationPolarizationType.calculated option enabled.
This option makes use of an alternative constraint for the feed-side, membrane-interface concentration.
Additionally, two more variables are created when this option is enabled: Kf - feed-channel
mass transfer coefficients at the channel inlet and outlet.
"""
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = props.NaClParameterBlock()
m.fs.unit = ReverseOsmosis0D(default={
"property_package": m.fs.properties,
"has_pressure_change": True,
"concentration_polarization_type": ConcentrationPolarizationType.calculated,
"mass_transfer_coefficient": MassTransferCoefficient.fixed})
# fully specify system
feed_flow_mass = 1
feed_mass_frac_NaCl = 0.035
feed_pressure = 50e5
feed_temperature = 273.15 + 25
membrane_pressure_drop = 3e5
membrane_area = 50
A = 4.2e-12
B = 3.5e-8
pressure_atmospheric = 101325
kf = 2e-5
feed_mass_frac_H2O = 1 - feed_mass_frac_NaCl
m.fs.unit.inlet.flow_mass_phase_comp[0, 'Liq', 'NaCl'].fix(
feed_flow_mass * feed_mass_frac_NaCl)
m.fs.unit.inlet.flow_mass_phase_comp[0, 'Liq', 'H2O'].fix(
feed_flow_mass * feed_mass_frac_H2O)
m.fs.unit.inlet.pressure[0].fix(feed_pressure)
m.fs.unit.inlet.temperature[0].fix(feed_temperature)
m.fs.unit.deltaP.fix(-membrane_pressure_drop)
m.fs.unit.area.fix(membrane_area)
m.fs.unit.A_comp.fix(A)
m.fs.unit.B_comp.fix(B)
m.fs.unit.permeate.pressure[0].fix(pressure_atmospheric)
m.fs.unit.Kf[0, 0., 'NaCl'].fix(kf)
m.fs.unit.Kf[0, 1., 'NaCl'].fix(kf)
# test statistics
assert number_variables(m) == 125
assert number_total_constraints(m) == 96
assert number_unused_variables(m) == 7 # vars from property package parameters
# test degrees of freedom
assert degrees_of_freedom(m) == 0
# test scaling
m.fs.properties.set_default_scaling('flow_mass_phase_comp', 1, index=('Liq', 'H2O'))
m.fs.properties.set_default_scaling('flow_mass_phase_comp', 1e2, index=('Liq', 'NaCl'))
calculate_scaling_factors(m)
# check that all variables have scaling factors.
# TODO: Setting the "include_fixed" arg as True reveals
# unscaled vars that weren't being accounted for previously. However, calling the whole block (i.e.,
# m) shows that several NaCl property parameters are unscaled. For now, we are just interested in ensuring
# unit variables are scaled (hence, calling m.fs.unit) but might need to revisit scaling and associated
# testing for property models.
unscaled_var_list = list(unscaled_variables_generator(m.fs.unit, include_fixed=True))
assert len(unscaled_var_list) == 0
# # test initialization
initialization_tester(m, fail_on_warning=True)
# test variable scaling
badly_scaled_var_lst = list(badly_scaled_var_generator(m))
assert badly_scaled_var_lst == []
# test solve
results = solver.solve(m)
# Check for optimal solution
assert_optimal_termination(results)
# test solution
assert (pytest.approx(3.815e-3, rel=1e-3) ==
value(m.fs.unit.flux_mass_phase_comp_avg[0, 'Liq', 'H2O']))
assert (pytest.approx(1.668e-6, rel=1e-3) ==
value(m.fs.unit.flux_mass_phase_comp_avg[0, 'Liq', 'NaCl']))
assert (pytest.approx(0.1908, rel=1e-3) ==
value(m.fs.unit.mixed_permeate[0].flow_mass_phase_comp['Liq', 'H2O']))
assert (pytest.approx(8.337e-5, rel=1e-3) ==
value(m.fs.unit.mixed_permeate[0].flow_mass_phase_comp['Liq', 'NaCl']))
assert (pytest.approx(46.07, rel=1e-3) ==
value(m.fs.unit.feed_side.properties_interface[0, 0.].conc_mass_phase_comp['Liq', 'NaCl']))
assert (pytest.approx(44.34, rel=1e-3) ==
value(m.fs.unit.feed_side.properties_out[0].conc_mass_phase_comp['Liq', 'NaCl']))
assert (pytest.approx(50.20, rel=1e-3) ==
value(m.fs.unit.feed_side.properties_interface[0, 1.].conc_mass_phase_comp['Liq', 'NaCl']))
def test_Pdrop_calculation(self):
"""Testing 0D-RO with PressureChangeType.calculated option."""
m = ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = props.NaClParameterBlock()
m.fs.unit = ReverseOsmosis0D(
default={
"property_package": m.fs.properties,
"has_pressure_change": True,
"concentration_polarization_type":
ConcentrationPolarizationType.calculated,
"mass_transfer_coefficient":
MassTransferCoefficient.calculated,
"pressure_change_type": PressureChangeType.calculated,
})
# fully specify system
feed_flow_mass = 1 / 3.6
feed_mass_frac_NaCl = 0.035
feed_mass_frac_H2O = 1 - feed_mass_frac_NaCl
feed_pressure = 70e5
feed_temperature = 273.15 + 25
membrane_area = 19
A = 4.2e-12
B = 3.5e-8
pressure_atmospheric = 101325
m.fs.unit.inlet.flow_mass_phase_comp[0, "Liq", "NaCl"].fix(
feed_flow_mass * feed_mass_frac_NaCl)
m.fs.unit.inlet.flow_mass_phase_comp[0, "Liq", "H2O"].fix(
feed_flow_mass * feed_mass_frac_H2O)
m.fs.unit.inlet.pressure[0].fix(feed_pressure)
m.fs.unit.inlet.temperature[0].fix(feed_temperature)
m.fs.unit.area.fix(membrane_area)
m.fs.unit.A_comp.fix(A)
m.fs.unit.B_comp.fix(B)
m.fs.unit.permeate.pressure[0].fix(pressure_atmospheric)
m.fs.unit.channel_height.fix(0.001)
m.fs.unit.spacer_porosity.fix(0.97)
m.fs.unit.length.fix(16)
# test statistics
assert number_variables(m) == 147
assert number_total_constraints(m) == 118
assert number_unused_variables(
m) == 0 # vars from property package parameters
# test degrees of freedom
assert degrees_of_freedom(m) == 0
# test scaling
m.fs.properties.set_default_scaling("flow_mass_phase_comp",
1,
index=("Liq", "H2O"))
m.fs.properties.set_default_scaling("flow_mass_phase_comp",
1e2,
index=("Liq", "NaCl"))
calculate_scaling_factors(m)
# check that all variables have scaling factors.
# TODO: see aforementioned TODO on revisiting scaling and associated testing for property models.
unscaled_var_list = list(
unscaled_variables_generator(m.fs.unit, include_fixed=True))
assert len(unscaled_var_list) == 0
# test initialization
initialization_tester(m, fail_on_warning=True)
# test variable scaling
badly_scaled_var_lst = list(badly_scaled_var_generator(m))
assert badly_scaled_var_lst == []
# test solve
results = solver.solve(m, tee=True)
# Check for optimal solution
assert_optimal_termination(results)
# test solution
assert pytest.approx(-1.661e5, rel=1e-3) == value(m.fs.unit.deltaP[0])
assert pytest.approx(-1.038e4, rel=1e-3) == value(m.fs.unit.deltaP[0] /
m.fs.unit.length)
assert pytest.approx(395.8, rel=1e-3) == value(m.fs.unit.N_Re[0, 0.0])
assert pytest.approx(0.2361,
rel=1e-3) == value(m.fs.unit.velocity[0, 0.0])
assert pytest.approx(191.1, rel=1e-3) == value(m.fs.unit.N_Re[0, 1.0])
assert pytest.approx(0.1187,
rel=1e-3) == value(m.fs.unit.velocity[0, 1.0])
assert pytest.approx(7.089e-3, rel=1e-3) == value(
m.fs.unit.flux_mass_phase_comp_avg[0, "Liq", "H2O"])
assert pytest.approx(2.188e-6, rel=1e-3) == value(
m.fs.unit.flux_mass_phase_comp_avg[0, "Liq", "NaCl"])
assert pytest.approx(0.1347, rel=1e-3) == value(
m.fs.unit.mixed_permeate[0].flow_mass_phase_comp["Liq", "H2O"])
assert pytest.approx(4.157e-5, rel=1e-3) == value(
m.fs.unit.mixed_permeate[0].flow_mass_phase_comp["Liq", "NaCl"])
assert pytest.approx(50.08, rel=1e-3) == value(
m.fs.unit.feed_side.properties_interface[
0, 0.0].conc_mass_phase_comp["Liq", "NaCl"])
assert pytest.approx(70.80, rel=1e-3) == value(
m.fs.unit.feed_side.properties_out[0].conc_mass_phase_comp["Liq",
"NaCl"])
assert pytest.approx(76.32, rel=1e-3) == value(
m.fs.unit.feed_side.properties_interface[
0, 1.0].conc_mass_phase_comp["Liq", "NaCl"])