def test_initialize(self, RO_frame):
initialization_tester(RO_frame)
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_io - 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_io[0, 'in', 'NaCl'].fix(kf)
m.fs.unit.Kf_io[0, 'out', 'NaCl'].fix(kf)
# test statistics
assert number_variables(m) == 94
assert number_total_constraints(m) == 65
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
# check that all constraints have been scaled
unscaled_constraint_list = list(unscaled_constraints_generator(m))
assert len(unscaled_constraint_list) == 0
# test initialization
initialization_tester(m)
# test variable scaling
badly_scaled_var_lst = list(badly_scaled_var_generator(m))
assert badly_scaled_var_lst == []
# test solve
solver.options = {'nlp_scaling_method': 'user-scaling'}
results = solver.solve(m)
# Check for optimal solution
assert results.solver.termination_condition == \
TerminationCondition.optimal
assert results.solver.status == SolverStatus.ok
# test solution
assert (pytest.approx(3.807e-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(0.1904, rel=1e-3) == value(
m.fs.unit.properties_permeate[0].flow_mass_phase_comp['Liq',
'H2O']))
assert (pytest.approx(8.342e-5, rel=1e-3) == value(
m.fs.unit.properties_permeate[0].flow_mass_phase_comp['Liq',
'NaCl']))
assert (pytest.approx(35.751, rel=1e-3) == value(
m.fs.unit.feed_side.properties_in[0].conc_mass_phase_comp['Liq',
'NaCl']))
assert (pytest.approx(46.123, rel=1e-3) == value(
m.fs.unit.feed_side.properties_interface_in[0].
conc_mass_phase_comp['Liq', 'NaCl']))
assert (pytest.approx(44.321, rel=1e-3) == value(
m.fs.unit.feed_side.properties_out[0].conc_mass_phase_comp['Liq',
'NaCl'])
)
assert (pytest.approx(50.081, rel=1e-3) == value(
m.fs.unit.feed_side.properties_interface_out[0].
conc_mass_phase_comp['Liq', 'NaCl']))
def test_initialize(self, model):
initialization_tester(model)
def test_initialize(self, iapws):
initialization_tester(iapws)
def test_initialize(self, btx):
initialization_tester(btx)
def test_initialize(self, sapon):
initialization_tester(sapon)
def test_initialize(solid_prop):
initialization_tester(
solid_prop)