##############################################################################
# Institute for the Design of Advanced Energy Systems Process Systems
# Engineering Framework (IDAES PSE Framework) Copyright (c) 2018, by the
# software owners: The Regents of the University of California, through
# Lawrence Berkeley National Laboratory, National Technology & Engineering
# Solutions of Sandia, LLC, Carnegie Mellon University, West Virginia
# University Research Corporation, et al. All rights reserved.
#
# Please see the files COPYRIGHT.txt and LICENSE.txt for full copyright and
# license information, respectively. Both files are also available online
# at the URL "https://github.com/IDAES/idaes".
##############################################################################
"""
Standard IDAES temperature changer model.
"""
from __future__ import division
# Import Python libraries
import logging
# Import Pyomo libraries
from pyomo.environ import value, Var
from pyomo.common.config import ConfigValue, In
# Import IDAES cores
from idaes.core import UnitBlockData, declare_process_block_class, \
Holdup0D, CONFIG_Base
from idaes.core.util.config import is_parameter_block, list_of_strings
from idaes.core.util.misc import add_object_ref
__author__ = "Andrew Lee"
# Set up logger
logger = logging.getLogger('idaes.unit_model')
[docs]@declare_process_block_class("TemperatureChanger")
class TemperatureChangerData(UnitBlockData):
"""
Standard Temperature Changer Unit Model Class
"""
CONFIG = CONFIG_Base()
# Set default values of inherited attributes
CONFIG.get('include_holdup')._default = False
CONFIG.get("material_balance_type")._default = 'component_phase'
CONFIG.get("energy_balance_type")._default = 'total'
CONFIG.get("momentum_balance_type")._default = 'total'
CONFIG.get("has_rate_reactions")._default = False
CONFIG.get("has_equilibrium_reactions")._default = False
CONFIG.get("has_phase_equilibrium")._default = True
CONFIG.get("has_mass_transfer")._default = False
CONFIG.get("has_heat_transfer")._default = True
CONFIG.get("has_work_transfer")._default = False
CONFIG.get("has_pressure_change")._default = False
# Add unit model attributes
CONFIG.declare("property_package", ConfigValue(
default=None,
domain=is_parameter_block,
description="Property package to use for holdup",
doc="""Property parameter object used to define property calculations
(default = 'use_parent_value')
- 'use_parent_value' - get package from parent (default = None)
- a ParameterBlock object"""))
CONFIG.declare("property_package_args", ConfigValue(
default={},
description="Arguments to use for constructing property packages",
doc="""A dict of arguments to be passed to the PropertyBlockData
and used when constructing these
(default = 'use_parent_value')
- 'use_parent_value' - get package from parent (default = None)
- a dict (see property package for documentation)"""))
CONFIG.declare("inlet_list", ConfigValue(
domain=list_of_strings,
description="List of inlet names",
doc="""A list containing names of inlets (default = None)
- None - default single inlet
- list - a list of names for inlets"""))
CONFIG.declare("num_inlets", ConfigValue(
domain=int,
description="Number of inlets to unit",
doc="""Argument indication number (int) of inlets to construct
(default = None). Not used if inlet_list arg is provided.
- None - use inlet_list arg instead
- int - Inlets will be named with sequential numbers from 1
to num_inlets"""))
CONFIG.declare("outlet_list", ConfigValue(
domain=list_of_strings,
description="List of outlet names",
doc="""A list containing names of outlets (default = None)
- None - default single outlet
- list - a list of names for outlets"""))
CONFIG.declare("num_outlets", ConfigValue(
domain=int,
description="Number of outlets to unit",
doc="""Argument indication number (int) of outlets to construct
(default = None). Not used if outlet_list arg is provided.
- None - use outlet_list arg instead
- int - Outlets will be named with sequential numbers from 1
to num_outlets"""))
CONFIG.declare("heater", ConfigValue(
default=True,
domain=In([True, False]),
description="Heater flag",
doc="""Indicates whether this unit should be considered a
heater (True (default), temperature increase) or a cooler
(False, temperature decrease)."""))
[docs] def build(self):
"""
Begin building model (pre-DAE transformation)
Args:
None
Returns:
None
"""
# Call UnitModel.build to setup dynamics
super(TemperatureChangerData, self).build()
# Build Holdup Block
self.holdup = Holdup0D()
# Set Unit Geometry and Holdup Volume
self._set_geometry()
# Construct performance equations
self._make_performance()
[docs] def post_transform_build(self):
"""
Continue model construction after DAE transformation
Args:
None
Returns:
None
"""
# Construct Inlets
self.build_inlets(inlets=self.config.inlet_list,
num_inlets=self.config.num_inlets)
# Build Outlets
self.build_outlets(outlets=self.config.outlet_list,
num_outlets=self.config.num_outlets)
def _set_geometry(self):
"""
Define the geometry of the unit as necessary, and link to holdup volume
Args:
None
Returns:
None
"""
# For this case, just create a reference to holdup volume
if self.config.include_holdup is True:
add_object_ref(self, "volume", self.holdup.volume)
def _make_performance(self):
"""
Define constraints which describe the behaviour of the unit model.
Args:
None
Returns:
None
"""
# Add reference to heat term
add_object_ref(self, "heat", self.holdup.heat)
# Add performance variables
self.deltaT = Var(self.time,
doc="Temperature difference in unit")
# detaT constraint
@self.Constraint(self.time, doc="Temperature difference calculation")
def temperature_difference(b, t):
return b.deltaT[t] == (b.holdup.properties_out[t].temperature -
b.holdup.properties_in[t].temperature)
[docs] def model_check(blk):
"""
Check that temperature change matches with heater argument (i.e. if
heater = True, temperature should increase).
Args:
None
Returns:
None
"""
if blk.config.heater:
# Heater
# Check that temperature does not decrease
if any(blk.deltaT[t].fixed and
(value(blk.deltaT[t]) < 0.0) for t in blk.time):
logger.warning('{} Heater set with negative deltaT.'
.format(blk.name))
if any(blk.holdup.properties_out[t].temperature.fixed and
(value(blk.holdup.properties_in[t].temperature) >
value(blk.holdup.properties_out[t].temperature))
for t in blk.time):
logger.warning('{} Heater set with temperature decrease.'
.format(blk.name))
# Check that work is not negative
if any(blk.heat[t].fixed and (value(blk.heat[t]) < 0.0)
for t in blk.time):
logger.warning('{} Heater maybe set with negative heat duty.'
.format(blk.name))
else:
# Cooler
# Check that temperature does not increase
if any(blk.deltaT[t].fixed and
(value(blk.deltaT[t]) > 0.0) for t in blk.time):
logger.warning('{} Cooler set with positive deltaT.'
.format(blk.name))
if any(blk.holdup.properties_out[t].temperature.fixed and
(value(blk.holdup.properties_in[t].temperature) <
value(blk.holdup.properties_out[t].temperature))
for t in blk.time):
logger.warning('{} Cooler maybe set with temperature ',
'increase.'.format(blk.name))
# Check that heat is not positive
if any(blk.heat[t].fixed and (value(blk.heat[t]) > 0.0)
for t in blk.time):
logger.warning('{} Cooler maybe set with positive heat duty.'
.format(blk.name))
# Run holdup block model checks
blk.holdup.model_check()