def initialize(self, outlvl=idaeslog.NOTSET, optarg=None, solver=None):
"""
Initialization routine for mixer.
Keyword Arguments:
outlvl : sets output level of initialization routine
optarg : solver options dictionary object (default=None, use
default solver options)
solver : str indicating which solver to use during
initialization (default = None, use default solver)
Returns:
None
"""
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit")
# Create solver
opt = get_solver(solver, optarg)
# This shouldn't require too much initializtion, just fixing inlets
# and solving should always work.
# sp is what to save to make sure state after init is same as the start
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
for b in self.inlet_blocks.values():
for bdat in b.values():
bdat.pressure.fix()
bdat.enth_mol.fix()
bdat.flow_mol.fix()
for t, v in self.outlet.pressure.items():
if not v.fixed:
v.value = min([
value(self.inlet_blocks[i][t].pressure)
for i in self.inlet_blocks
])
self.outlet.unfix()
if (hasattr(self, "pressure_equality_constraints")
and self.pressure_equality_constraints.active):
# If using the equal pressure constraint fix the outlet and free
# the inlet pressures, this is typical for pressure driven flow
for i, b in self.inlet_blocks.items():
for bdat in b.values():
bdat.pressure.unfix()
self.outlet.pressure.fix()
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)))
from_json(self, sd=istate, wts=sp)
def initialize(
self,
outlvl=idaeslog.NOTSET,
solver=None,
optarg={},
):
"""
For simplicity this initialization requires you to set values for the
efficency, inlet, and one of pressure ratio, pressure change or outlet
pressure.
"""
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit")
# Create solver
slvr = get_solver(solver, optarg)
# Store original specification so initialization doesn't change the model
# This will only resore the values of varaibles that were originally fixed
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
# Check for alternate pressure specs
for t in self.flowsheet().config.time:
if self.outlet.pressure[t].fixed:
self.ratioP[t] = pyo.value(
self.outlet.pressure[t]/self.inlet.pressure[t])
elif self.control_volume.deltaP[t].fixed:
self.ratioP[t] = pyo.value(
(self.control_volume.deltaP[t] + self.inlet.pressure[t])/
self.inlet.pressure[t]
)
# Fix the variables we base the initializtion on and free the rest.
# This requires good values to be provided for pressure, efficency,
# and inlet conditions, but it is simple and reliable.
self.inlet.fix()
self.outlet.unfix()
self.ratioP.fix()
self.deltaP.unfix()
self.efficiency_isentropic.fix()
for t in self.flowsheet().config.time:
self.outlet.pressure[t] = pyo.value(
self.inlet.pressure[t]*self.ratioP[t])
self.deltaP[t] = pyo.value(
self.outlet.pressure[t] - self.inlet.pressure[t])
self.outlet.enth_mol[t] = pyo.value(self.h_o[t])
self.control_volume.work[t] = pyo.value(
self.inlet.flow_mol[t]*self.inlet.enth_mol[t] -
self.outlet.flow_mol[t]*self.outlet.enth_mol[t]
)
self.outlet.flow_mol[t] = pyo.value(self.inlet.flow_mol[t])
# Solve the model (should be already solved from above)
with idaeslog.solver_log(solve_log, idaeslog.DEBUG) as slc:
res = slvr.solve(self, tee=slc.tee)
from_json(self, sd=istate, wts=sp)
def initialize(self, **kwargs):
# store original state
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
# check for fixed outlet flows and use them to calculate fixed split
# fractions
for t in self.flowsheet().config.time:
for o in self.outlet_list:
elec_obj = getattr(self, o + "_elec")
if elec_obj[t].fixed:
self.split_fraction[o, t].fix(
value(elec_obj[t] / self.electricity[t]))
# fix or unfix split fractions so n - 1 are fixed
for t in self.flowsheet().config.time:
# see how many split fractions are fixed
n = sum(1 for o in self.outlet_list
if self.split_fraction[o, t].fixed)
# if number of outlets - 1 we're good
if n == len(self.outlet_list) - 1:
continue
# if too many are fixed, unfix the first, generally assume that is
# the main flow, and is the calculated split fraction
elif n == len(self.outlet_list):
self.split_fraction[self.outlet_list[0], t].unfix()
# if not enough fixed, start fixing from the back until there are
# are enough
else:
for o in reversed(self.outlet_list):
if not self.split_fraction[o, t].fixed:
self.split_fraction[o, t].fix()
n += 1
if n == len(self.outlet_list) - 1:
break
self.electricity.fix()
for o in self.outlet_list:
getattr(self, o + "_port").unfix()
assert degrees_of_freedom(self) == 0
solver = "ipopt"
if "solver" in kwargs:
solver = kwargs["solver"]
opt = SolverFactory(solver)
opt.solve(self)
from_json(self, sd=istate, wts=sp)
def initialize(self, *args, **kwargs):
"""
Use the regular heat exchanger initialization, with the extraction rate
constraint deactivated; then it activates the constraint and calculates
a steam inlet flow rate.
"""
solver = kwargs.get("solver", None)
optarg = kwargs.get("oparg", {})
outlvl = kwargs.get("outlvl", idaeslog.NOTSET)
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit")
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
self.area.fix()
self.overall_heat_transfer_coefficient.fix()
self.inlet_1.fix()
self.inlet_2.fix()
self.outlet_1.unfix()
self.outlet_2.unfix()
# Do condenser initialization
self.inlet_1.flow_mol.unfix()
# fix volume and pressure drop since
# the condenser initialization dosen't require them
self.side_1.volume.fix(10)
self.side_1.deltaP.fix(0)
self.shell_volume_eqn.deactivate()
self.pressure_change_total_eqn.deactivate()
super().initialize()
self.side_1.volume.unfix()
self.side_1.deltaP.unfix()
self.shell_volume_eqn.activate()
self.pressure_change_total_eqn.activate()
# Create solver
opt = get_solver(solver, optarg)
with idaeslog.solver_log(solve_log, idaeslog.DEBUG) as slc:
res = opt.solve(self, tee=slc.tee)
init_log.info(
"Initialization Complete (w/ steam flow calc): {}".format(
idaeslog.condition(res)
)
)
from_json(self, sd=istate, wts=sp)
def initialize(
self,
outlvl=idaeslog.NOTSET,
solver=None,
optarg=None,
):
"""
For simplicity this initialization requires you to set values for the
efficency, inlet, and one of pressure ratio, pressure change or outlet
pressure.
"""
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit")
# Create solver
opt = get_solver(solver, optarg)
# Store original specification so initialization doesn't change the model
# This will only resore the values of varaibles that were originally fixed
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
# Check for alternate pressure specs
for t in self.flowsheet().time:
if self.outlet.pressure[t].fixed:
self.deltaP[t].fix(
pyo.value(self.outlet.pressure[t] -
self.inlet.pressure[t]))
self.outlet.pressure[t].unfix()
elif self.deltaP[t].fixed:
# No outlet pressure specified guess a small pressure drop
self.outlet.pressure[t] = pyo.value(self.inlet.pressure[t] +
self.deltaP[t])
self.inlet.fix()
self.outlet.unfix()
for t, v in self.deltaP.items():
if v.fixed:
self.inlet.flow_mol[t].unfix()
with idaeslog.solver_log(solve_log, idaeslog.DEBUG) as slc:
res = opt.solve(self, tee=slc.tee)
from_json(self, sd=istate, wts=sp)
def test04(self):
"""
Like test03, but this StoreSpec also saves/loads active/deactivated
component attribute and parameter values.
"""
model = self.setup_model02()
x = model.x
x[1].fix(1)
wts = StoreSpec.value_isfixed_isactive(only_fixed=True)
to_json(model, fname=self.fname, human_read=True, wts=wts)
x[1].unfix()
x[1].value = 2
x[2].value = 10
model.g.deactivate()
from_json(model, fname=self.fname, wts=wts)
assert (x[1].fixed)
assert (abs(value(x[1]) - 1) < 1e-5)
assert (abs(value(x[2]) - 10) < 1e-5)
assert (model.g.active)
def initialize(self, *args, **kwargs):
"""
Use the regular heat exchanger initialization, with the extraction rate
constraint deactivated; then it activates the constraint and calculates
a steam inlet flow rate.
"""
solver = kwargs.get("solver", "ipopt")
optarg = kwargs.get("oparg", {})
outlvl = kwargs.get("outlvl", idaeslog.NOTSET)
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit")
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
self.extraction_rate_constraint.deactivate()
self.area.fix()
self.overall_heat_transfer_coefficient.fix()
self.inlet_1.fix()
self.inlet_2.fix()
self.outlet_1.unfix()
self.outlet_2.unfix()
# Do regular heat exchanger intialization
super().initialize(*args, **kwargs)
self.extraction_rate_constraint.activate()
self.inlet_1.flow_mol.unfix()
opt = SolverFactory(solver)
opt.options = optarg
with idaeslog.solver_log(solve_log, idaeslog.DEBUG) as slc:
res = opt.solve(self, tee=slc.tee)
init_log.info(
"Initialization Complete (w/ extraction calc): {}".format(
idaeslog.condition(res)))
from_json(self, sd=istate, wts=sp)
def initialize(self, *args, **kwargs):
"""
Use the regular heat exchanger initilization, with the extraction rate
constraint deactivated; then it activates the constraint and calculates
a steam inlet flow rate.
"""
self.extraction_rate_constraint.deactivate()
super().initialize(*args, **kwargs)
self.extraction_rate_constraint.activate()
solver = kwargs.get("solver", "ipopt")
optarg = kwargs.get("oparg", {})
outlvl = kwargs.get("outlvl", 0)
opt = SolverFactory(solver)
opt.options = optarg
tee = True if outlvl >= 3 else False
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
self.area.fix()
self.overall_heat_transfer_coefficient.fix()
self.inlet_1.fix()
self.inlet_2.fix()
self.outlet_1.unfix()
self.outlet_2.unfix()
self.inlet_1.flow_mol.unfix()
results = opt.solve(self, tee=tee)
if results.solver.termination_condition == TerminationCondition.optimal:
if outlvl >= 2:
_log.info('{} Initialization Failed.'.format(self.name))
else:
_log.warning('{} Initialization Failed.'.format(self.name))
from_json(self, sd=istate, wts=sp)
def initialize(
self,
state_args_1=None,
state_args_2=None,
unfix='hot_flow',
outlvl=idaeslog.NOTSET,
solver=None,
optarg=None,
):
"""
Condenser initialization method. The initialization routine assumes
fixed area and heat transfer coefficient and adjusts the cooling water
flow to condense steam to saturated water at shell side pressure.
Args:
state_args_1 : a dict of arguments to be passed to the property
initialization for hot side (see documentation of the specific
property package) (default = None).
state_args_2 : a dict of arguments to be passed to the property
initialization for cold side (see documentation of the specific
property package) (default = None).
optarg : solver options dictionary object (default=None, use
default solver options)
solver : str indicating which solver to use during
initialization (default = None, use default solver)
Returns:
None
"""
if unfix not in {"hot_flow", "cold_flow", "pressure"}:
raise Exception("Condenser free variable must be in 'hot_flow', "
"'cold_flow', or 'pressure'")
# Set solver options
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit")
hot_side = getattr(self, self.config.hot_side_name)
cold_side = getattr(self, self.config.cold_side_name)
# Store initial model specs, restored at the end of initializtion, so
# the problem is not altered. This can restore fixed/free vars,
# active/inactive constraints, and fixed variable values.
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
# Create solver
opt = get_solver(solver, optarg)
flags1 = hot_side.initialize(outlvl=outlvl,
optarg=optarg,
solver=solver,
state_args=state_args_1)
flags2 = cold_side.initialize(outlvl=outlvl,
optarg=optarg,
solver=solver,
state_args=state_args_2)
init_log.info_high("Initialization Step 1 Complete.")
# Solve with all constraints activated
self.saturation_eqn.activate()
if unfix == 'pressure':
hot_side.properties_in[:].pressure.unfix()
elif unfix == 'hot_flow':
hot_side.properties_in[:].flow_mol.unfix()
elif unfix == 'cold_flow':
cold_side.properties_in[:].flow_mol.unfix()
with idaeslog.solver_log(solve_log, idaeslog.DEBUG) as slc:
res = opt.solve(self, tee=slc.tee)
init_log.info_high("Initialization Step 4 {}.".format(
idaeslog.condition(res)))
# Release Inlet state
hot_side.release_state(flags1, outlvl)
cold_side.release_state(flags2, outlvl)
from_json(self, sd=istate, wts=sp)
def initialize(self, *args, **kwargs):
config = self.config # sorter ref to config for less line splitting
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
# the initilization here isn't straight forward since the heat exchanger
# may have 3 stages and they are countercurrent. For simplicity each
# stage in initialized with the same cooling water inlet conditions then
# the whole feedwater heater is solved together. There are more robust
# approaches which can be implimented if the need arises.
# initialize desuperheat if include
if config.has_desuperheat:
if config.has_drain_cooling:
_set_port(self.desuperheat.inlet_2, self.cooling.inlet_2)
else:
_set_port(self.desuperheat.inlet_2, self.condense.inlet_2)
self.desuperheat.initialize(*args, **kwargs)
self.desuperheat.inlet_1.flow_mol.unfix()
if config.has_drain_mixer:
_set_port(self.drain_mix.steam, self.desuperheat.outlet_1)
else:
_set_port(self.condense.inlet_1, self.desuperheat.outlet_1)
# fix the steam and fwh inlet for init
self.desuperheat.inlet_1.fix()
self.desuperheat.inlet_1.flow_mol.unfix() #unfix for extract calc
# initialize mixer if included
if config.has_drain_mixer:
self.drain_mix.steam.fix()
self.drain_mix.drain.fix()
self.drain_mix.outlet.unfix()
self.drain_mix.initialize(*args, **kwargs)
_set_port(self.condense.inlet_1, self.drain_mix.outlet)
if config.has_desuperheat:
self.drain_mix.steam.unfix()
else:
self.drain_mix.steam.flow_mol.unfix()
# Initialize condense section
if config.has_drain_cooling:
_set_port(self.condense.inlet_2, self.cooling.inlet_2)
self.cooling.inlet_2.fix()
else:
self.condense.inlet_2.fix()
self.condense.initialize(*args, **kwargs)
# Initialize drain cooling if included
if config.has_drain_cooling:
_set_port(self.cooling.inlet_1, self.condense.outlet_1)
self.cooling.initialize(*args, **kwargs)
# Solve all together
outlvl = kwargs.get("outlvl", 0)
opt = SolverFactory(kwargs.get("solver", "ipopt"))
opt.options = kwargs.get("oparg", {})
tee = True if outlvl >= 3 else False
assert (degrees_of_freedom(self) == 0)
results = opt.solve(self, tee=tee)
if results.solver.termination_condition == TerminationCondition.optimal:
if outlvl >= 2:
_log.info('{} Initialization Complete.'.format(self.name))
else:
_log.warning('{} Initialization Failed.'.format(self.name))
from_json(self, sd=istate, wts=sp)
def initialize(
self,
state_args={},
outlvl=idaeslog.NOTSET,
solver="ipopt",
optarg={
"tol": 1e-6,
"max_iter": 30
},
):
"""
Initialize the outlet turbine stage model. This deactivates the
specialized constraints, then does the isentropic turbine initialization,
then reactivates the constraints and solves.
Args:
state_args (dict): Initial state for property initialization
outlvl : sets output level of initialization routine
solver (str): Solver to use for initialization
optarg (dict): Solver arguments dictionary
"""
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit")
# sp is what to save to make sure state after init is same as the start
# saves value, fixed, and active state, doesn't load originally free
# values, this makes sure original problem spec is same but initializes
# the values of free vars
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
# Deactivate special constraints
self.stodola_equation.deactivate()
self.efficiency_correlation.deactivate()
self.deltaP.unfix()
self.ratioP.unfix()
# Fix turbine parameters + eff_isen
self.eff_dry.fix()
self.design_exhaust_flow_vol.fix()
self.flow_coeff.fix()
# fix inlet and free outlet
for t in self.flowsheet().config.time:
for k, v in self.inlet.vars.items():
v[t].fix()
for k, v in self.outlet.vars.items():
v[t].unfix()
# If there isn't a good guess for efficiency or outlet pressure
# provide something reasonable.
eff = self.efficiency_isentropic[t]
eff.fix(
eff.value if value(eff) > 0.3 and value(eff) < 1.0 else 0.8)
# for outlet pressure try outlet pressure, pressure ratio, delta P,
# then if none of those look reasonable use a pressure ratio of 0.8
# to calculate outlet pressure
Pout = self.outlet.pressure[t]
Pin = self.inlet.pressure[t]
prdp = value((self.deltaP[t] - Pin) / Pin)
if value(Pout / Pin) > 0.95 or value(Pout / Pin) < 0.003:
if value(self.ratioP[t]) < 0.9 and value(
self.ratioP[t]) > 0.01:
Pout.fix(value(Pin * self.ratioP))
elif prdp < 0.9 and prdp > 0.01:
Pout.fix(value(prdp * Pin))
else:
Pout.fix(value(Pin * 0.3))
else:
Pout.fix()
self.deltaP[:] = value(Pout - Pin)
self.ratioP[:] = value(Pout / Pin)
for t in self.flowsheet().config.time:
self.properties_isentropic[t].pressure.value = value(
self.outlet.pressure[t])
self.properties_isentropic[t].flow_mol.value = value(
self.inlet.flow_mol[t])
self.properties_isentropic[t].enth_mol.value = value(
self.inlet.enth_mol[t] * 0.95)
self.outlet.flow_mol[t].value = value(self.inlet.flow_mol[t])
self.outlet.enth_mol[t].value = value(self.inlet.enth_mol[t] *
0.95)
# Make sure the initialization problem has no degrees of freedom
# This shouldn't happen here unless there is a bug in this
dof = degrees_of_freedom(self)
try:
assert dof == 0
except AssertionError:
init_log.error("Degrees of freedom not 0, ({})".format(dof))
raise
mw = self.control_volume.properties_in[0].mw
Tin = self.control_volume.properties_in[0].temperature
Pin = self.control_volume.properties_in[0].pressure
Pr = self.ratioP[0]
cf = self.flow_coeff
self.inlet.flow_mol.fix(
value(cf * Pin * sqrt(1 - Pr**2) / mw / sqrt(Tin - 273.15)))
# one bad thing about reusing this is that the log messages aren't
# really compatible with being nested inside another initialization
super().initialize(state_args=state_args,
outlvl=outlvl,
solver=solver,
optarg=optarg)
# Free eff_isen and activate sepcial constarints
self.efficiency_isentropic.unfix()
self.outlet.pressure.fix()
self.inlet.flow_mol.unfix()
self.stodola_equation.activate()
self.efficiency_correlation.activate()
slvr = SolverFactory(solver)
slvr.options = optarg
with idaeslog.solver_log(solve_log, idaeslog.DEBUG) as slc:
res = slvr.solve(self, tee=slc.tee)
init_log.info("Initialization Complete (Outlet Stage): {}".format(
idaeslog.condition(res)))
# reload original spec
from_json(self, sd=istate, wts=sp)
def initialize(
self,
state_args={},
outlvl=0,
solver="ipopt",
optarg={
"tol": 1e-6,
"max_iter": 30
},
):
"""
Initialize the turbine stage model. This deactivates the
specialized constraints, then does the isentropic turbine initialization,
then reactivates the constraints and solves.
Args:
state_args (dict): Initial state for property initialization
outlvl (int): Amount of output (0 to 3) 0 is lowest
solver (str): Solver to use for initialization
optarg (dict): Solver arguments dictionary
"""
stee = True if outlvl >= 3 else False
# sp is what to save to make sure state after init is same as the start
# saves value, fixed, and active state, doesn't load originally free
# values, this makes sure original problem spec is same but initializes
# the values of free vars
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
# fix inlet and free outlet
for t in self.flowsheet().config.time:
for k, v in self.inlet.vars.items():
v[t].fix()
for k, v in self.outlet.vars.items():
v[t].unfix()
# If there isn't a good guess for efficiency or outlet pressure
# provide something reasonable.
eff = self.efficiency_isentropic[t]
eff.fix(
eff.value if value(eff) > 0.3 and value(eff) < 1.0 else 0.8)
# for outlet pressure try outlet pressure, pressure ratio, delta P,
# then if none of those look reasonable use a pressure ratio of 0.8
# to calculate outlet pressure
Pout = self.outlet.pressure[t]
Pin = self.inlet.pressure[t]
prdp = value((self.deltaP[t] - Pin) / Pin)
if self.deltaP[t].fixed:
Pout.value = value(Pin - Pout)
if self.ratioP[t].fixed:
Pout.value = value(self.ratioP[t] * Pin)
if value(Pout / Pin) > 0.99 or value(Pout / Pin) < 0.1:
if value(self.ratioP[t]) < 0.99 and value(
self.ratioP[t]) > 0.1:
Pout.fix(value(Pin * self.ratioP[t]))
elif prdp < 0.99 and prdp > 0.1:
Pout.fix(value(prdp * Pin))
else:
Pout.fix(value(Pin * 0.8))
else:
Pout.fix()
self.deltaP[t] = value(Pout - Pin)
self.ratioP[t] = value(Pout / Pin)
self.deltaP[:].unfix()
self.ratioP[:].unfix()
for t in self.flowsheet().config.time:
self.properties_isentropic[t].pressure.value = value(
self.outlet.pressure[t])
self.properties_isentropic[t].flow_mol.value = value(
self.inlet.flow_mol[t])
self.properties_isentropic[t].enth_mol.value = value(
self.inlet.enth_mol[t] * 0.95)
self.outlet.flow_mol[t].value = value(self.inlet.flow_mol[t])
self.outlet.enth_mol[t].value = value(self.inlet.enth_mol[t] *
0.95)
# Make sure the initialization problem has no degrees of freedom
# This shouldn't happen here unless there is a bug in this
dof = degrees_of_freedom(self)
try:
assert dof == 0
except:
_log.exception("degrees_of_freedom = {}".format(dof))
raise
# one bad thing about reusing this is that the log messages aren't
# really compatible with being nested inside another initialization
super(TurbineStageData, self).initialize(state_args=state_args,
outlvl=outlvl,
solver=solver,
optarg=optarg)
# reload original spec
from_json(self, sd=istate, wts=sp)
def initialize(
self,
state_args={},
outlvl=idaeslog.NOTSET,
solver="ipopt",
optarg={
"tol": 1e-6,
"max_iter": 30
},
calculate_cf=True,
):
"""
Initialize the outlet turbine stage model. This deactivates the
specialized constraints, then does the isentropic turbine initialization,
then reactivates the constraints and solves.
Args:
state_args (dict): Initial state for property initialization
outlvl : sets output level of initialization routine
solver (str): Solver to use for initialization
optarg (dict): Solver arguments dictionary
"""
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit")
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
# sp is what to save to make sure state after init is same as the start
# saves value, fixed, and active state, doesn't load originally free
# values, this makes sure original problem spec is same but initializes
# the values of free vars
for t in self.flowsheet().config.time:
if self.outlet.pressure[t].fixed:
self.ratioP[t] = value(self.outlet.pressure[t] /
self.inlet.pressure[t])
self.deltaP[t] = value(self.outlet.pressure[t] -
self.inlet.pressure[t])
# Deactivate special constraints
self.stodola_equation.deactivate()
self.efficiency_correlation.deactivate()
self.efficiency_isentropic.fix()
self.deltaP.unfix()
self.ratioP.unfix()
self.inlet.fix()
self.outlet.unfix()
super().initialize(outlvl=outlvl, solver=solver, optarg=optarg)
for t in self.flowsheet().config.time:
mw = self.control_volume.properties_in[t].mw
Tin = self.control_volume.properties_in[t].temperature
Pin = self.control_volume.properties_in[t].pressure
Pr = self.ratioP[t]
if not calculate_cf:
cf = self.flow_coeff
self.inlet.flow_mol[t].fix(
value(cf * Pin * sqrt(1 - Pr**2) / mw / sqrt(Tin)))
super().initialize(outlvl=outlvl, solver=solver, optarg=optarg)
self.control_volume.properties_out[:].pressure.fix()
# Free eff_isen and activate sepcial constarints
self.efficiency_isentropic.unfix()
self.outlet.pressure.fix()
if calculate_cf:
self.flow_coeff.unfix()
self.inlet.flow_mol.unfix()
self.inlet.flow_mol[0].fix()
flow = self.control_volume.properties_in[0].flow_mol
mw = self.control_volume.properties_in[0].mw
Tin = self.control_volume.properties_in[0].temperature
Pin = self.control_volume.properties_in[0].pressure
Pr = self.ratioP[0]
self.flow_coeff.value = value(flow * mw * sqrt(Tin / (1 - Pr**2)) /
Pin)
else:
self.inlet.flow_mol.unfix()
self.stodola_equation.activate()
self.efficiency_correlation.activate()
slvr = SolverFactory(solver)
slvr.options = optarg
self.display()
with idaeslog.solver_log(solve_log, idaeslog.DEBUG) as slc:
res = slvr.solve(self, tee=slc.tee)
init_log.info("Initialization Complete (Outlet Stage): {}".format(
idaeslog.condition(res)))
# reload original spec
if calculate_cf:
cf = value(self.flow_coeff)
from_json(self, sd=istate, wts=sp)
if calculate_cf:
# cf was probably fixed, so will have to set the value agian here
# if you ask for it to be calculated.
self.flow_coeff = cf
def initialize(self,
outlvl=idaeslog.NOTSET,
solver="ipopt",
optarg={
"tol": 1e-6,
"max_iter": 35
},
copy_disconneted_flow=True,
copy_disconneted_pressure=True,
calculate_outlet_cf=False,
calculate_inlet_cf=False):
"""
Initialize
Args:
outlvl: logging level default is NOTSET, which inherits from the
parent logger
solver: the NL solver, default is "ipopt"
optarg: solver arguments, default is {"tol": 1e-6, "max_iter": 35}
copy_disconneted_flow: Copy the flow through the disconnected stages
default is True
copy_disconneted_pressure: Copy the pressure through the disconnected
stages default is True
calculate_outlet_cf: Use the flow initial flow guess to calculate
the outlet stage flow coefficient, default is False,
calculate_inlet_cf: Use the inlet stage ratioP to calculate the flow
coefficent for the inlet stage default is False
Returns:
None
"""
# Setup loggers
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit")
# Store initial model specs, restored at the end of initializtion, so
# the problem is not altered. This can restore fixed/free vars,
# active/inactive constraints, and fixed variable values.
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
# Assume the flow into the turbine is a reasonable guess for
# initializtion
flow_guess = self.inlet_split.inlet.flow_mol[0].value
for it_count in range(2):
self.inlet_split.initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
# Initialize valves
for i in self.inlet_stage_idx:
u = self.throttle_valve[i]
copy_port(u.inlet,
getattr(self.inlet_split, "outlet_{}".format(i)))
u.initialize(outlvl=outlvl, solver=solver, optarg=optarg)
# Initialize turbine
for i in self.inlet_stage_idx:
u = self.inlet_stage[i]
copy_port(u.inlet, self.throttle_valve[i].outlet)
u.initialize(outlvl=outlvl,
solver=solver,
optarg=optarg,
calculate_cf=calculate_inlet_cf)
# Initialize Mixer
self.inlet_mix.use_minimum_inlet_pressure_constraint()
for i in self.inlet_stage_idx:
copy_port(
getattr(self.inlet_mix, "inlet_{}".format(i)),
self.inlet_stage[i].outlet,
)
getattr(self.inlet_mix, "inlet_{}".format(i)).fix()
self.inlet_mix.initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
for i in self.inlet_stage_idx:
getattr(self.inlet_mix, "inlet_{}".format(i)).unfix()
self.inlet_mix.use_equal_pressure_constraint()
prev_port = self.inlet_mix.outlet
prev_port = self._init_section(
self.hp_stages,
self.hp_split,
self.config.hp_disconnect,
prev_port,
outlvl,
solver,
optarg,
copy_disconneted_flow=copy_disconneted_flow,
copy_disconneted_pressure=copy_disconneted_pressure,
)
if len(self.hp_stages) in self.config.hp_disconnect:
self.config.ip_disconnect.append(0)
prev_port = self._init_section(
self.ip_stages,
self.ip_split,
self.config.ip_disconnect,
prev_port,
outlvl,
solver,
optarg,
copy_disconneted_flow=copy_disconneted_flow,
copy_disconneted_pressure=copy_disconneted_pressure,
)
if len(self.ip_stages) in self.config.ip_disconnect:
self.config.lp_disconnect.append(0)
prev_port = self._init_section(
self.lp_stages,
self.lp_split,
self.config.lp_disconnect,
prev_port,
outlvl,
solver,
optarg,
copy_disconneted_flow=copy_disconneted_flow,
copy_disconneted_pressure=copy_disconneted_pressure,
)
copy_port(self.outlet_stage.inlet, prev_port)
print(
"********************* start to initialize outlet stage *******************"
)
print("calculate_outlet_cf = ", calculate_outlet_cf)
print("inlet flow=", self.outlet_stage.inlet.flow_mol[0].value)
print("inlet enth=", self.outlet_stage.inlet.enth_mol[0].value)
print("inlet pres=", self.outlet_stage.inlet.pressure[0].value)
self.outlet_stage.initialize(outlvl=outlvl,
solver=solver,
optarg=optarg,
calculate_cf=calculate_outlet_cf)
print(
"********************* end of initialize outlet stage *******************"
)
if calculate_outlet_cf:
break
for t in self.inlet_split.inlet.flow_mol:
self.inlet_split.inlet.flow_mol[t].value = \
self.outlet_stage.inlet.flow_mol[t].value *1.2 # Revised to avoid too low main steam flow
if calculate_inlet_cf:
# cf was probably fixed, so will have to set the value agian here
# if you ask for it to be calculated.
icf = {}
for i in self.inlet_stage:
for t in self.inlet_stage[i].flow_coeff:
icf[i, t] = pyo.value(self.inlet_stage[i].flow_coeff[t])
if calculate_outlet_cf:
ocf = pyo.value(self.outlet_stage.flow_coeff)
from_json(self, sd=istate, wts=sp)
if calculate_inlet_cf:
# cf was probably fixed, so will have to set the value agian here
# if you ask for it to be calculated.
for t in self.inlet_stage[i].flow_coeff:
for i in self.inlet_stage:
self.inlet_stage[i].flow_coeff[t] = icf[i, t]
if calculate_outlet_cf:
self.outlet_stage.flow_coeff = ocf
def initialize(self, state_args={}, outlvl=0, solver='ipopt',
optarg={'tol': 1e-6, 'max_iter':30}):
"""
Initialize the inlet turbine stage model. This deactivates the
specialized constraints, then does the isentropic turbine initialization,
then reactivates the constraints and solves.
Args:
state_args (dict): Initial state for property initialization
outlvl (int): Amount of output (0 to 3) 0 is lowest
solver (str): Solver to use for initialization
optarg (dict): Solver arguments dictionary
"""
stee = True if outlvl >= 3 else False
# sp is what to save to make sure state after init is same as the start
# saves value, fixed, and active state, doesn't load originally free
# values, this makes sure original problem spec is same but initializes
# the values of free vars
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
# Deactivate special constraints
self.inlet_flow_constraint.deactivate()
self.isentropic_enthalpy.deactivate()
self.efficiency_correlation.deactivate()
self.deltaP.unfix()
self.ratioP.unfix()
# Fix turbine parameters + eff_isen
self.eff_nozzle.fix()
self.blade_reaction.fix()
self.flow_coeff.fix()
self.blade_velocity.fix()
# fix inlet and free outlet
for t in self.flowsheet().config.time:
for k, v in self.inlet.vars.items():
v[t].fix()
for k, v in self.outlet.vars.items():
v[t].unfix()
# If there isn't a good guess for efficeny or outlet pressure
# provide something reasonable.
eff = self.efficiency_isentropic[t]
eff.fix(eff.value if value(eff) > 0.3 and value(eff) < 1.0 else 0.8)
# for outlet pressure try outlet pressure, pressure ratio, delta P,
# then if none of those look reasonable use a pressure ratio of 0.8
# to calculate outlet pressure
Pout = self.outlet.pressure[t]
Pin = self.inlet.pressure[t]
prdp = value((self.deltaP[t] - Pin)/Pin)
if value(Pout/Pin) > 0.98 or value(Pout/Pin) < 0.3:
if value(self.ratioP[t]) < 0.98 and value(self.ratioP[t]) > 0.3:
Pout.fix(value(Pin*self.ratioP))
elif prdp < 0.98 and prdp > 0.3:
Pout.fix(value(prdp*Pin))
else:
Pout.fix(value(Pin*0.8))
else:
Pout.fix()
self.deltaP[:] = value(Pout - Pin)
self.ratioP[:] = value(Pout/Pin)
for t in self.flowsheet().config.time:
self.properties_isentropic[t].pressure.value = \
value(self.outlet.pressure[t])
self.properties_isentropic[t].flow_mol.value = \
value(self.inlet.flow_mol[t])
self.properties_isentropic[t].enth_mol.value = \
value(self.inlet.enth_mol[t]*0.95)
self.outlet.flow_mol[t].value = \
value(self.inlet.flow_mol[t])
self.outlet.enth_mol[t].value = \
value(self.inlet.enth_mol[t]*0.95)
# Make sure the initialization problem has no degrees of freedom
# This shouldn't happen here unless there is a bug in this
dof = degrees_of_freedom(self)
try:
assert(dof == 0)
except:
_log.exception("degrees_of_freedom = {}".format(dof))
raise
# one bad thing about reusing this is that the log messages aren't
# really compatible with being nested inside another initialization
super(TurbineInletStageData, self).initialize(state_args=state_args,
outlvl=outlvl, solver=solver, optarg=optarg)
# Free eff_isen and activate sepcial constarints
self.efficiency_isentropic.unfix()
self.outlet.pressure.unfix()
self.inlet_flow_constraint.activate()
self.isentropic_enthalpy.activate()
self.efficiency_correlation.activate()
slvr = SolverFactory(solver)
slvr.options = optarg
res = slvr.solve(self, tee=stee)
if outlvl > 0:
if res.solver.termination_condition == TerminationCondition.optimal:
_log.info("{} Initialization Complete.".format(self.name))
else:
_log.warning(
"""{} Initialization Failed. The most likely cause of initialization failure for
the Turbine inlet stages model is that the flow coefficient is not compatible
with flow rate guess.""".format(self.name))
# reload original spec
from_json(self, sd=istate, wts=sp)
def initialize(self, *args, **kwargs):
outlvl = kwargs.get("outlvl", idaeslog.NOTSET)
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit")
config = self.config # shorter ref to config for less line splitting
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
# the initialization here isn't straight forward since the heat exchanger
# may have 3 stages and they are countercurrent. For simplicity each
# stage in initialized with the same cooling water inlet conditions then
# the whole feedwater heater is solved together. There are more robust
# approaches which can be implimented if the need arises.
# initialize desuperheat if include
if config.has_desuperheat:
if config.has_drain_cooling:
_set_port(self.desuperheat.inlet_2, self.cooling.inlet_2)
else:
_set_port(self.desuperheat.inlet_2, self.condense.inlet_2)
self.desuperheat.initialize(*args, **kwargs)
self.desuperheat.inlet_1.flow_mol.unfix()
if config.has_drain_mixer:
_set_port(self.drain_mix.steam, self.desuperheat.outlet_1)
else:
_set_port(self.condense.inlet_1, self.desuperheat.outlet_1)
# fix the steam and fwh inlet for init
self.desuperheat.inlet_1.fix()
self.desuperheat.inlet_1.flow_mol.unfix() # unfix for extract calc
# initialize mixer if included
if config.has_drain_mixer:
self.drain_mix.steam.fix()
self.drain_mix.drain.fix()
self.drain_mix.outlet.unfix()
self.drain_mix.initialize(*args, **kwargs)
_set_port(self.condense.inlet_1, self.drain_mix.outlet)
if config.has_desuperheat:
self.drain_mix.steam.unfix()
else:
self.drain_mix.steam.flow_mol.unfix()
# Initialize condense section
if config.has_drain_cooling:
_set_port(self.condense.inlet_2, self.cooling.inlet_2)
self.cooling.inlet_2.fix()
else:
self.condense.inlet_2.fix()
if not config.has_drain_mixer and not config.has_desuperheat:
self.condense.inlet_1.fix()
self.condense.inlet_1.flow_mol.unfix()
tempsat = value(self.condense.shell.properties_in[0].temperature_sat)
temp = value(self.condense.tube.properties_in[0].temperature)
if tempsat - temp < 30:
init_log.warning(
"The steam sat. temperature ({}) is near the feedwater"
" inlet temperature ({})".format(tempsat, temp))
self.condense.initialize(*args, **kwargs)
# Initialize drain cooling if included
if config.has_drain_cooling:
_set_port(self.cooling.inlet_1, self.condense.outlet_1)
self.cooling.initialize(*args, **kwargs)
# Solve all together
opt = SolverFactory(kwargs.get("solver", "ipopt"))
opt.options = kwargs.get("oparg", {})
assert degrees_of_freedom(self) == 0
with idaeslog.solver_log(solve_log, idaeslog.DEBUG) as slc:
res = opt.solve(self, tee=slc.tee)
init_log.info("Condensing shell inlet delta T = {}".format(
value(self.condense.delta_temperature_in[0])))
init_log.info("Condensing Shell outlet delta T = {}".format(
value(self.condense.delta_temperature_out[0])))
init_log.info("Steam Flow = {}".format(
value(self.condense.inlet_1.flow_mol[0])))
init_log.info("Initialization Complete: {}".format(
idaeslog.condition(res)))
from_json(self, sd=istate, wts=sp)
def initialize(
self,
outlvl=idaeslog.NOTSET,
solver="ipopt",
optarg={"tol": 1e-6, "max_iter": 35},
copy_disconneted_flow=True,
):
"""
Initialize
"""
# sp is what to save to make sure state after init is same as the start
# saves value, fixed, and active state, doesn't load originally free
# values, this makes sure original problem spec is same but
# initializes the values of free vars
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
ni = self.config.num_parallel_inlet_stages
def init_section(stages, splits, disconnects, prev_port):
if 0 in splits:
_set_port(splits[0].inlet, prev_port)
splits[0].initialize(
outlvl=outlvl, solver=solver, optarg=optarg)
prev_port = splits[0].outlet_1
for i in stages:
if i - 1 not in disconnects:
_set_port(stages[i].inlet, prev_port)
else:
if copy_disconneted_flow:
for t in stages[i].stages[i].inlet.flow_mol:
stages[i].inlet.flow_mol[t] = \
prev_port.flow_mol[t]
stages[i].initialize(
outlvl=outlvl, solver=solver, optarg=optarg)
prev_port = stages[i].outlet
if i in splits:
_set_port(splits[i].inlet, prev_port)
splits[i].initialize(
outlvl=outlvl, solver=solver, optarg=optarg)
prev_port = splits[i].outlet_1
return prev_port
for k in [1, 2]:
# Initialize Splitter
# Fix n - 1 split fractions
self.inlet_split.split_fraction[0, "outlet_1"].value = 1.0 / ni
for i in self.inlet_stage_idx:
if i == 1: # fix rest of splits at leaving first one free
continue
self.inlet_split.split_fraction[
0, "outlet_{}".format(i)].fix(1.0 / ni)
# fix inlet and free outlet
self.inlet_split.inlet.fix()
for i in self.inlet_stage_idx:
ol = getattr(self.inlet_split, "outlet_{}".format(i))
ol.unfix()
self.inlet_split.initialize(
outlvl=outlvl, solver=solver, optarg=optarg)
# free split fractions
for i in self.inlet_stage_idx:
self.inlet_split.split_fraction[
0, "outlet_{}".format(i)].unfix()
# Initialize valves
for i in self.inlet_stage_idx:
_set_port(
self.throttle_valve[i].inlet,
getattr(self.inlet_split, "outlet_{}".format(i)),
)
self.throttle_valve[i].initialize(
outlvl=outlvl, solver=solver, optarg=optarg
)
# Initialize turbine
for i in self.inlet_stage_idx:
_set_port(
self.inlet_stage[i].inlet, self.throttle_valve[i].outlet)
self.inlet_stage[i].initialize(
outlvl=outlvl, solver=solver, optarg=optarg
)
# Initialize Mixer
self.inlet_mix.use_minimum_inlet_pressure_constraint()
for i in self.inlet_stage_idx:
_set_port(
getattr(self.inlet_mix, "inlet_{}".format(i)),
self.inlet_stage[i].outlet,
)
getattr(self.inlet_mix, "inlet_{}".format(i)).fix()
self.inlet_mix.initialize(
outlvl=outlvl, solver=solver, optarg=optarg)
for i in self.inlet_stage_idx:
getattr(self.inlet_mix, "inlet_{}".format(i)).unfix()
self.inlet_mix.use_equal_pressure_constraint()
prev_port = self.inlet_mix.outlet
prev_port = init_section(
self.hp_stages,
self.hp_split,
self.config.hp_disconnect,
prev_port
)
if len(self.hp_stages) in self.config.hp_disconnect:
prev_port = self.ip_stages[1].inlet
prev_port = init_section(
self.ip_stages,
self.ip_split,
self.config.ip_disconnect,
prev_port
)
if len(self.ip_stages) in self.config.ip_disconnect:
prev_port = self.lp_stages[1].inlet
prev_port = init_section(
self.lp_stages,
self.lp_split,
self.config.lp_disconnect,
prev_port
)
_set_port(self.outlet_stage.inlet, prev_port)
self.outlet_stage.initialize(
outlvl=outlvl, solver=solver, optarg=optarg)
for t in self.flowsheet().time:
self.inlet_split.inlet.flow_mol[
t
].value = self.outlet_stage.inlet.flow_mol[t].value
from_json(self, sd=istate, wts=sp)
def initialize(self,
outlvl=0,
solver='ipopt',
optarg={
'tol': 1e-6,
'max_iter': 35
}):
"""
Initialize
"""
stee = True if outlvl >= 3 else False
# sp is what to save to make sure state after init is same as the start
# saves value, fixed, and active state, doesn't load originally free
# values, this makes sure original problem spec is same but initializes
# the values of free vars
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
ni = self.config.num_parallel_inlet_stages
# Initialize Splitter
# Fix n - 1 split fractions
self.inlet_split.split_fraction[0, "outlet_1"].value = 1.0 / ni
for i in self.inlet_stage_idx:
if i == 1: #fix rest of splits at leaving first one free
continue
self.inlet_split.split_fraction[0, "outlet_{}".format(i)].fix(1.0 /
ni)
# fix inlet and free outlet
self.inlet_split.inlet.fix()
for i in self.inlet_stage_idx:
ol = getattr(self.inlet_split, "outlet_{}".format(i))
ol.unfix()
self.inlet_split.initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
# free split fractions
for i in self.inlet_stage_idx:
self.inlet_split.split_fraction[0, "outlet_{}".format(i)].unfix()
# Initialize valves
for i in self.inlet_stage_idx:
_set_port(self.throttle_valve[i].inlet,
getattr(self.inlet_split, "outlet_{}".format(i)))
self.throttle_valve[i].initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
# Initialize turbine
for i in self.inlet_stage_idx:
_set_port(self.inlet_stage[i].inlet, self.throttle_valve[i].outlet)
self.inlet_stage[i].initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
# Initialize Mixer
self.inlet_mix.use_minimum_inlet_pressure_constraint()
for i in self.inlet_stage_idx:
_set_port(getattr(self.inlet_mix, "inlet_{}".format(i)),
self.inlet_stage[i].outlet)
getattr(self.inlet_mix, "inlet_{}".format(i)).fix()
self.inlet_mix.initialize(outlvl=outlvl, solver=solver, optarg=optarg)
for i in self.inlet_stage_idx:
getattr(self.inlet_mix, "inlet_{}".format(i)).unfix()
self.inlet_mix.use_equal_pressure_constraint()
def init_section(stages, splits, disconnects, prev_port):
if 0 in splits:
_set_port(splits[0].inlet, prev_port)
splits[0].initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
prev_port = splits[0].outlet_1
for i in stages:
if i - 1 not in disconnects:
_set_port(stages[i].inlet, prev_port)
stages[i].initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
prev_port = stages[i].outlet
if i in splits:
_set_port(splits[i].inlet, prev_port)
splits[i].initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
prev_port = splits[i].outlet_1
return prev_port
prev_port = self.inlet_mix.outlet
prev_port = init_section(self.hp_stages, self.hp_split,
self.config.hp_disconnect, prev_port)
if len(self.hp_stages) in self.config.hp_disconnect:
prev_port = self.ip_stages[1].inlet
prev_port = init_section(self.ip_stages, self.ip_split,
self.config.ip_disconnect, prev_port)
if len(self.ip_stages) in self.config.ip_disconnect:
prev_port = self.lp_stages[1].inlet
prev_port = init_section(self.lp_stages, self.lp_split,
self.config.lp_disconnect, prev_port)
_set_port(self.outlet_stage.inlet, prev_port)
self.outlet_stage.initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
from_json(self, sd=istate, wts=sp)
def initialize(self,
state_args={},
outlvl=0,
solver='ipopt',
optarg={
'tol': 1e-6,
'max_iter': 30
}):
"""
Initialize the turbine stage model. This deactivates the
specialized constraints, then does the isentropic turbine initialization,
then reactivates the constraints and solves.
Args:
state_args (dict): Initial state for property initialization
outlvl (int): Amount of output (0 to 3) 0 is lowest
solver (str): Solver to use for initialization
optarg (dict): Solver arguments dictionary
"""
stee = True if outlvl >= 3 else False
# sp is what to save to make sure state after init is same as the start
# saves value, fixed, and active state, doesn't load originally free
# values, this makes sure original problem spec is same but initializes
# the values of free vars
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
self.deltaP[:].unfix()
self.ratioP[:].unfix()
# fix inlet and free outlet
for t in self.flowsheet().config.time:
for k, v in self.inlet.vars.items():
v[t].fix()
for k, v in self.outlet.vars.items():
v[t].unfix()
# to calculate outlet pressure
Pout = self.outlet.pressure[t]
Pin = self.inlet.pressure[t]
if self.deltaP[t].value is not None:
prdp = value((self.deltaP[t] - Pin) / Pin)
else:
prdp = -100 # crazy number to say don't use deltaP as guess
if value(Pout / Pin) > 1 or value(Pout / Pin) < 0.0:
if value(self.ratioP[t]) <= 1 and value(self.ratioP[t]) >= 0:
Pout.value = value(Pin * self.ratioP[t])
elif prdp <= 1 and prdp >= 0:
Pout.value = value(prdp * Pin)
else:
Pout.value = value(Pin * 0.95)
self.deltaP[t] = value(Pout - Pin)
self.ratioP[t] = value(Pout / Pin)
# Make sure the initialization problem has no degrees of freedom
# This shouldn't happen here unless there is a bug in this
dof = degrees_of_freedom(self)
try:
assert (dof == 0)
except:
_log.exception("degrees_of_freedom = {}".format(dof))
raise
# one bad thing about reusing this is that the log messages aren't
# really compatible with being nested inside another initialization
super().initialize(state_args=state_args,
outlvl=outlvl,
solver=solver,
optarg=optarg)
# reload original spec
from_json(self, sd=istate, wts=sp)
def initialize(self,
outlvl=idaeslog.NOTSET,
solver="ipopt",
optarg={
"tol": 1e-6,
"max_iter": 35
}):
"""
Initialize
"""
# sp is what to save to make sure state after init is same as the start
# saves value, fixed, and active state, doesn't load originally free
# values, this makes sure original problem spec is same but initializes
# the values of free vars
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit")
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
ni = self.config.num_parallel_inlet_stages
flow_guess = self.inlet_split.inlet.flow_mol[0].value
def init_section(stages, splits, disconnects, prev_port):
if 0 in splits:
_set_port(splits[0].inlet, prev_port)
splits[0].initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
prev_port = splits[0].outlet_1
for i in stages:
if i - 1 not in disconnects:
_set_port(stages[i].inlet, prev_port)
stages[i].initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
prev_port = stages[i].outlet
if i in splits:
_set_port(splits[i].inlet, prev_port)
splits[i].initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
prev_port = splits[i].outlet_1
return prev_port
for k in [1]:
# Initialize Splitter
# Fix n - 1 split fractions
self.inlet_split.split_fraction[0, "outlet_1"].value = 1.0 / ni
for i in self.inlet_stage_idx:
if i == 1: # fix rest of splits at leaving first one free
continue
self.inlet_split.split_fraction[0, "outlet_{}".format(i)].fix(
1.0 / ni)
# fix inlet and free outlet
self.inlet_split.inlet.fix()
for i in self.inlet_stage_idx:
ol = getattr(self.inlet_split, "outlet_{}".format(i))
ol.unfix()
self.inlet_split.initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
# free split fractions
for i in self.inlet_stage_idx:
self.inlet_split.split_fraction[0,
"outlet_{}".format(i)].unfix()
# Initialize valves
for i in self.inlet_stage_idx:
_set_port(
self.throttle_valve[i].inlet,
getattr(self.inlet_split, "outlet_{}".format(i)),
)
self.throttle_valve[i].initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
# Initialize turbine
for i in self.inlet_stage_idx:
_set_port(self.inlet_stage[i].inlet,
self.throttle_valve[i].outlet)
self.inlet_stage[i].initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
# Initialize Mixer
self.inlet_mix.use_minimum_inlet_pressure_constraint()
for i in self.inlet_stage_idx:
_set_port(
getattr(self.inlet_mix, "inlet_{}".format(i)),
self.inlet_stage[i].outlet,
)
getattr(self.inlet_mix, "inlet_{}".format(i)).fix()
self.inlet_mix.initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
for i in self.inlet_stage_idx:
getattr(self.inlet_mix, "inlet_{}".format(i)).unfix()
self.inlet_mix.use_equal_pressure_constraint()
prev_port = self.inlet_mix.outlet
prev_port = init_section(self.hp_stages, self.hp_split,
self.config.hp_disconnect, prev_port)
if len(self.hp_stages) in self.config.hp_disconnect:
prev_port = self.ip_stages[1].inlet
prev_port = init_section(self.ip_stages, self.ip_split,
self.config.ip_disconnect, prev_port)
if len(self.ip_stages) in self.config.ip_disconnect:
prev_port = self.lp_stages[1].inlet
prev_port = init_section(self.lp_stages, self.lp_split,
self.config.lp_disconnect, prev_port)
_set_port(self.outlet_stage.inlet, prev_port)
self.outlet_stage.initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
for t in self.flowsheet().time:
self.inlet_split.inlet.flow_mol[
t].value = self.outlet_stage.inlet.flow_mol[t].value
slvr = SolverFactory(solver)
slvr.options = optarg
init_log.info_high("Solve full multistage turbine")
self.inlet_split.inlet.flow_mol.unfix()
with idaeslog.solver_log(solve_log, idaeslog.DEBUG) as slc:
res = slvr.solve(self, tee=slc.tee)
init_log.info(
"Flow guess: {}, Initialized Flow: {}".format(
flow_guess, self.outlet_stage.inlet.flow_mol[0].value), )
init_log.info("Initialization Complete: {}".format(
idaeslog.condition(res)))
from_json(self, sd=istate, wts=sp)
def initialize(self,
outlvl=idaeslog.NOTSET,
solver=None,
flow_iterate=2,
optarg=None,
copy_disconneted_flow=True,
copy_disconneted_pressure=True,
calculate_outlet_cf=False,
calculate_inlet_cf=False):
"""
Initialize
Args:
outlvl: logging level default is NOTSET, which inherits from the
parent logger
solver: the NL solver
flow_iterate: If not calculating flow coefficients, this is the
number of times to update the flow and repeat initialization
(1 to 5 where 1 does not update the flow guess)
optarg: solver arguments, default is None
copy_disconneted_flow: Copy the flow through the disconnected stages
default is True
copy_disconneted_pressure: Copy the pressure through the disconnected
stages default is True
calculate_outlet_cf: Use the flow initial flow guess to calculate
the outlet stage flow coefficient, default is False,
calculate_inlet_cf: Use the inlet stage ratioP to calculate the flow
coefficent for the inlet stage default is False
Returns:
None
"""
# Setup loggers
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit")
# Store initial model specs, restored at the end of initializtion, so
# the problem is not altered. This can restore fixed/free vars,
# active/inactive constraints, and fixed variable values.
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
# Assume the flow into the turbine is a reasonable guess for
# initializtion
flow_guess = self.inlet_split.inlet.flow_mol[0].value
for it_count in range(flow_iterate):
self.inlet_split.initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
# Initialize valves
for i in self.inlet_stage_idx:
u = self.throttle_valve[i]
copy_port(u.inlet,
getattr(self.inlet_split, "outlet_{}".format(i)))
u.initialize(outlvl=outlvl, solver=solver, optarg=optarg)
# Initialize turbine
for i in self.inlet_stage_idx:
u = self.inlet_stage[i]
copy_port(u.inlet, self.throttle_valve[i].outlet)
u.initialize(outlvl=outlvl,
solver=solver,
optarg=optarg,
calculate_cf=calculate_inlet_cf)
# Initialize Mixer
self.inlet_mix.use_minimum_inlet_pressure_constraint()
for i in self.inlet_stage_idx:
copy_port(
getattr(self.inlet_mix, "inlet_{}".format(i)),
self.inlet_stage[i].outlet,
)
getattr(self.inlet_mix, "inlet_{}".format(i)).fix()
self.inlet_mix.initialize(outlvl=outlvl,
solver=solver,
optarg=optarg)
for i in self.inlet_stage_idx:
getattr(self.inlet_mix, "inlet_{}".format(i)).unfix()
self.inlet_mix.use_equal_pressure_constraint()
prev_port = self.inlet_mix.outlet
prev_port = self._init_section(
self.hp_stages,
self.hp_split,
self.config.hp_disconnect,
prev_port,
outlvl,
solver,
optarg,
copy_disconneted_flow=copy_disconneted_flow,
copy_disconneted_pressure=copy_disconneted_pressure,
)
if len(self.hp_stages) in self.config.hp_disconnect:
self.config.ip_disconnect.append(0)
prev_port = self._init_section(
self.ip_stages,
self.ip_split,
self.config.ip_disconnect,
prev_port,
outlvl,
solver,
optarg,
copy_disconneted_flow=copy_disconneted_flow,
copy_disconneted_pressure=copy_disconneted_pressure,
)
if len(self.ip_stages) in self.config.ip_disconnect:
self.config.lp_disconnect.append(0)
prev_port = self._init_section(
self.lp_stages,
self.lp_split,
self.config.lp_disconnect,
prev_port,
outlvl,
solver,
optarg,
copy_disconneted_flow=copy_disconneted_flow,
copy_disconneted_pressure=copy_disconneted_pressure,
)
copy_port(self.outlet_stage.inlet, prev_port)
self.outlet_stage.initialize(outlvl=outlvl,
solver=solver,
optarg=optarg,
calculate_cf=calculate_outlet_cf)
if calculate_outlet_cf:
break
if it_count < flow_iterate - 1:
for t in self.inlet_split.inlet.flow_mol:
self.inlet_split.inlet.flow_mol[t].value = \
self.outlet_stage.inlet.flow_mol[t].value
for s in self.hp_split.values():
for i, o in enumerate(s.outlet_list):
if i == 0:
continue
o = getattr(s, o)
self.inlet_split.inlet.flow_mol[t].value += \
o.flow_mol[t].value
for s in self.ip_split.values():
for i, o in enumerate(s.outlet_list):
if i == 0:
continue
o = getattr(s, o)
self.inlet_split.inlet.flow_mol[t].value += \
o.flow_mol[t].value
for s in self.lp_split.values():
for i, o in enumerate(s.outlet_list):
if i == 0:
continue
o = getattr(s, o)
self.inlet_split.inlet.flow_mol[t].value += \
o.flow_mol[t].value
if calculate_inlet_cf:
# cf was probably fixed, so will have to set the value agian here
# if you ask for it to be calculated.
icf = {}
for i in self.inlet_stage:
for t in self.inlet_stage[i].flow_coeff:
icf[i, t] = pyo.value(self.inlet_stage[i].flow_coeff[t])
if calculate_outlet_cf:
ocf = pyo.value(self.outlet_stage.flow_coeff)
from_json(self, sd=istate, wts=sp)
if calculate_inlet_cf:
# cf was probably fixed, so will have to set the value agian here
# if you ask for it to be calculated.
for t in self.inlet_stage[i].flow_coeff:
for i in self.inlet_stage:
self.inlet_stage[i].flow_coeff[t] = icf[i, t]
if calculate_outlet_cf:
self.outlet_stage.flow_coeff = ocf
def initialize(
self,
state_args={},
outlvl=idaeslog.NOTSET,
solver="ipopt",
optarg={"tol": 1e-6, "max_iter": 30},
calculate_cf=False,
):
"""
Initialize the inlet turbine stage model. This deactivates the
specialized constraints, then does the isentropic turbine initialization,
then reactivates the constraints and solves. This initializtion uses a
flow value guess, so some reasonable flow guess should be sepecified prior
to initializtion.
Args:
state_args (dict): Initial state for property initialization
outlvl (int): Amount of output (0 to 3) 0 is lowest
solver (str): Solver to use for initialization
optarg (dict): Solver arguments dictionary
calculate_cf (bool): If True, use the flow and pressure ratio to
calculate the flow coefficient.
"""
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit")
# sp is what to save to make sure state after init is same as the start
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
# Setup for initializtion step 1
self.inlet_flow_constraint.deactivate()
self.efficiency_correlation.deactivate()
self.eff_nozzle.fix()
self.blade_reaction.fix()
self.flow_coeff.fix()
self.blade_velocity.fix()
self.inlet.fix()
self.outlet.unfix()
for t in self.flowsheet().config.time:
self.efficiency_isentropic[t] = 0.9
super().initialize(outlvl=outlvl, solver=solver, optarg=optarg)
# Free eff_isen and activate sepcial constarints
self.inlet_flow_constraint.activate()
self.efficiency_correlation.activate()
if calculate_cf:
self.ratioP.fix()
self.flow_coeff.unfix()
for t in self.flowsheet().config.time:
g = self.control_volume.properties_in[t].heat_capacity_ratio
mw = self.control_volume.properties_in[t].mw
flow = self.control_volume.properties_in[t].flow_mol
Tin = self.control_volume.properties_in[t].temperature
Pin = self.control_volume.properties_in[t].pressure
Pratio = self.ratioP[t]
self.flow_coeff[t].value = value(
flow * mw * sqrt(
Tin/(g/(g - 1) *(Pratio**(2.0/g) - Pratio**((g + 1)/g)))
)/Pin
)
slvr = SolverFactory(solver)
slvr.options = optarg
with idaeslog.solver_log(solve_log, idaeslog.DEBUG) as slc:
res = slvr.solve(self, tee=slc.tee)
init_log.info("Initialization Complete: {}".format(idaeslog.condition(res)))
# reload original spec
if calculate_cf:
cf = {}
for t in self.flowsheet().config.time:
cf[t] = value(self.flow_coeff[t])
from_json(self, sd=istate, wts=sp)
if calculate_cf:
# cf was probably fixed, so will have to set the value agian here
# if you ask for it to be calculated.
for t in self.flowsheet().config.time:
self.flow_coeff[t] = cf[t]
def initialize(self, outlvl=idaeslog.NOTSET, optarg=None, solver=None):
"""
Initialization routine for splitter
Keyword Arguments:
outlvl: sets output level of initialization routine
optarg: solver options dictionary object (default=None, use
default solver options)
solver: str indicating which solver to use during
initialization (default = None, use default solver)
Returns:
If hold_states is True, returns a dict containing flags for which
states were fixed during initialization.
"""
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
solve_log = idaeslog.getSolveLogger(self.name, outlvl, tag="unit")
# Create solver
opt = get_solver(solver, optarg)
# sp is what to save to make sure state after init is same as the start
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
# check for fixed outlet flows and use them to calculate fixed split
# fractions
for t in self.flowsheet().config.time:
for o in self.outlet_list:
if self.outlet_blocks[o][t].flow_mol.fixed:
self.split_fraction[t, o].fix(
value(self.mixed_state[t] /
self.outlet_blocks[o][t].flow_mol))
# fix or unfix split fractions so n - 1 are fixed
for t in self.flowsheet().config.time:
# see how many split fractions are fixed
n = sum(1 for o in self.outlet_list
if self.split_fraction[t, o].fixed)
# if number of outlets - 1 we're good
if n == len(self.outlet_list) - 1:
continue
# if too mant are fixed un fix the first, generally assume that is
# the main flow, and is the calculated split fraction
if n == len(self.outlet_list):
self.split_fraction[t, self.outlet_list[0]].unfix()
# if not enough fixed, start fixing from the back until there are
# are enough
for o in reversed(self.outlet_list):
if not self.split_fraction[t, o].fixed:
self.split_fraction[t, o].fix()
n += 1
if n == len(self.outlet_list) - 1:
break
# This model is really simple so it should easily solve without much
# effort to initialize
self.inlet.fix()
for o, p in self.outlet_ports.items():
p.unfix()
assert degrees_of_freedom(self) == 0
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)))
from_json(self, sd=istate, wts=sp)
def initialize(
self,
state_args={},
outlvl=idaeslog.NOTSET,
solver="ipopt",
optarg={
"tol": 1e-6,
"max_iter": 30
},
):
"""
Initialize the valve based on a deltaP guess.
Args:
state_args (dict): Initial state for property initialization
outlvl : sets output level of initialization routine
solver (str): Solver to use for initialization
optarg (dict): Solver arguments dictionary
"""
init_log = idaeslog.getInitLogger(self.name, outlvl, tag="unit")
# storage settings what's fixed/free what's active/inactive and values
# only for orginally fixed things.
sp = StoreSpec.value_isfixed_isactive(only_fixed=True)
istate = to_json(self, return_dict=True, wts=sp)
self.deltaP[:].unfix()
self.ratioP[:].unfix()
# fix inlet and free outlet
for t in self.flowsheet().config.time:
for k, v in self.inlet.vars.items():
v[t].fix()
for k, v in self.outlet.vars.items():
v[t].unfix()
# to calculate outlet pressure
Pout = self.outlet.pressure[t]
Pin = self.inlet.pressure[t]
if self.deltaP[t].value is not None:
prdp = pyo.value((self.deltaP[t] - Pin) / Pin)
else:
prdp = -100 # crazy number to say don't use deltaP as guess
if pyo.value(Pout / Pin) > 1 or pyo.value(Pout / Pin) < 0.0:
if pyo.value(self.ratioP[t]) <= 1 and pyo.value(
self.ratioP[t]) >= 0:
Pout.value = pyo.value(Pin * self.ratioP[t])
elif prdp <= 1 and prdp >= 0:
Pout.value = pyo.value(prdp * Pin)
else:
Pout.value = pyo.value(Pin * 0.95)
self.deltaP[t] = pyo.value(Pout - Pin)
self.ratioP[t] = pyo.value(Pout / Pin)
# Make sure the initialization problem has no degrees of freedom
# This shouldn't happen here unless there is a bug in this
dof = degrees_of_freedom(self)
try:
assert dof == 0
except:
init_log.exception("degrees_of_freedom = {}".format(dof))
raise
# one bad thing about reusing this is that the log messages aren't
# really compatible with being nested inside another initialization
super().initialize(state_args=state_args,
outlvl=outlvl,
solver=solver,
optarg=optarg)
# reload original spec
from_json(self, sd=istate, wts=sp)