def build_phase_separator():
m = pyo.ConcreteModel()
m.fs = FlowsheetBlock(default={"dynamic": False})
m.fs.properties = iapws95.Iapws95ParameterBlock()
m.fs.unit = HelmPhaseSeparator(
default={'property_package': m.fs.properties})
return m
def build(self):
"""
Begin building model (pre-DAE transformation).
Args:
None
Returns:
None
"""
# Call UnitModel.build to setup dynamics
super().build()
# Build Control Volume
self.control_volume = ControlVolume0DBlock(default={
"dynamic": self.config.dynamic,
"has_holdup": self.config.has_holdup,
"property_package": self.config.property_package,
"property_package_args": self.config.property_package_args})
self.control_volume.add_geometry()
self.control_volume.add_state_blocks(has_phase_equilibrium=False)
self.control_volume.add_material_balances(
balance_type=self.config.material_balance_type,)
self.control_volume.add_energy_balances(
balance_type=self.config.energy_balance_type,
has_heat_transfer=self.config.has_heat_transfer)
self.control_volume.add_momentum_balances(
balance_type=self.config.momentum_balance_type,
has_pressure_change=True)
self.flash = HelmPhaseSeparator(
default={
"dynamic": False,
"property_package": self.config.property_package,
}
)
self.mixer = Mixer(
default={
"dynamic": False,
"property_package": self.config.property_package,
"inlet_list": ["FeedWater", "SaturatedWater"],
"mixed_state_block": self.control_volume.properties_in,
}
)
# instead of creating a new block use control volume to return solution
# Inlet Ports
# FeedWater to Drum (from Pipe or Economizer)
self.feedwater_inlet = Port(extends=self.mixer.FeedWater)
# Sat water from water wall
self.water_steam_inlet = Port(extends=self.flash.inlet)
# Exit Ports
# Liquid to Downcomer
# self.liquid_outlet = Port(extends=self.mixer.outlet)
self.add_outlet_port('liquid_outlet', self.control_volume)
# Steam to superheaters
self.steam_outlet = Port(extends=self.flash.vap_outlet)
# constraint to make pressures of two inlets of drum mixer the same
@self.Constraint(self.flowsheet().config.time,
doc="Mixter pressure identical")
def mixer_pressure_eqn(b, t):
return b.mixer.SaturatedWater.pressure[t]*1e-6 == \
b.mixer.FeedWater.pressure[t]*1e-6
self.stream_flash_out = Arc(
source=self.flash.liq_outlet, destination=self.mixer.SaturatedWater
)
# Pyomo arc connect flash liq_outlet with mixer SaturatedWater inlet
pyo.TransformationFactory("network.expand_arcs").apply_to(self)
# Add object references
self.volume = pyo.Reference(self.control_volume.volume)
# Set references to balance terms at unit level
if (self.config.has_heat_transfer is True and
self.config.energy_balance_type != EnergyBalanceType.none):
self.heat_duty = pyo.Reference(self.control_volume.heat)
if (self.config.has_pressure_change is True and
self.config.momentum_balance_type != 'none'):
self.deltaP = pyo.Reference(self.control_volume.deltaP)
# Set Unit Geometry and Holdup Volume
self._set_geometry()
# Construct performance equations
self._make_performance()