The example below shows how to setup and initialize a simple RO unit model.
# quiet idaes logs import idaes.logger as idaeslogger idaeslogger.getLogger('ideas.core').setLevel('CRITICAL') idaeslogger.getLogger('idaes.init').setLevel('CRITICAL')
from pyomo.environ import ConcreteModel from idaes.core import FlowsheetBlock from idaes.core.util.scaling import calculate_scaling_factors from watertap.property_models.NaCl_prop_pack import NaClParameterBlock from watertap.unit_models.reverse_osmosis_0D import ReverseOsmosis0D from watertap.unit_models.reverse_osmosis_0D import ConcentrationPolarizationType from watertap.unit_models.reverse_osmosis_0D import MassTransferCoefficient
# Create a concrete model, flowsheet, and NaCl property parameter block. m = ConcreteModel() m.fs = FlowsheetBlock(dynamic=False) m.fs.properties = NaClParameterBlock()
# Add an RO unit to the flowsheet. m.fs.unit = ReverseOsmosis0D( property_package=m.fs.properties, concentration_polarization_type=ConcentrationPolarizationType.none, mass_transfer_coefficient=MassTransferCoefficient.none, has_pressure_change=False)
# Specify system variables. m.fs.unit.inlet.flow_mass_phase_comp[0, 'Liq', 'NaCl'].fix(0.035) # mass flow rate of NaCl (kg/s) m.fs.unit.inlet.flow_mass_phase_comp[0, 'Liq', 'H2O'].fix(0.965) # mass flow rate of water (kg/s) m.fs.unit.inlet.pressure[0].fix(50e5) # feed pressure (Pa) m.fs.unit.inlet.temperature[0].fix(298.15) # feed temperature (K) m.fs.unit.area.fix(50) # membrane area (m^2) m.fs.unit.A_comp.fix(4.2e-12) # membrane water permeability (m/Pa/s) m.fs.unit.B_comp.fix(3.5e-8) # membrane salt permeability (m/s) m.fs.unit.permeate.pressure[0].fix(101325) # permeate pressure (Pa)
# Set scaling factors for component mass flowrates. 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. calculate_scaling_factors(m)
# Initialize the model. m.fs.unit.initialize()