Source code for idaes.core.process_base

##############################################################################
# Institute for the Design of Advanced Energy Systems Process Systems
# Engineering Framework (IDAES PSE Framework) Copyright (c) 2018-2020, 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-pse".
##############################################################################
"""
Base for IDAES process model objects.
"""

import sys
import logging
import textwrap

from pyomo.core.base.block import _BlockData
from pyomo.core.base.misc import tabular_writer
from pyomo.environ import Block, value
from pyomo.gdp import Disjunct
from pyomo.common.config import ConfigBlock
from enum import Enum

from idaes.core.process_block import declare_process_block_class
from idaes.core.util.exceptions import (ConfigurationError,
                                        DynamicError,
                                        PropertyPackageError)
from idaes.core.util.tables import stream_table_dataframe_to_string
from idaes.core.util.model_statistics import (degrees_of_freedom,
                                              number_variables,
                                              number_activated_constraints,
                                              number_activated_blocks)


# Some more inforation about this module
__author__ = "John Eslick, Qi Chen, Andrew Lee"


__all__ = ['ProcessBlockData']


useDefault = object()


# Set up logger
_log = logging.getLogger(__name__)


# Enumerate options for material flow basis
class MaterialFlowBasis(Enum):
    molar = 0
    mass = 1
    other = 2


[docs]@declare_process_block_class("ProcessBaseBlock") class ProcessBlockData(_BlockData): """ Base class for most IDAES process models and classes. The primary purpose of this class is to create the local config block to handle arguments provided by the user when constructing an object and to ensure that these arguments are stored in the config block. Additionally, this class contains a number of methods common to all IDAES classes. """ CONFIG = ConfigBlock("ProcessBlockData", implicit=False) def __init__(self, component): """ Initialize a ProcessBlockData object. Args: component(Block): container Block instance to which this _BlockData belongs. Returns: (ProcessBlockData): A new instance """ super(ProcessBlockData, self).__init__(component=component) self._pb_configured = False
[docs] def build(self): """ The build method is called by the default ProcessBlock rule. If a rule is sepecified other than the default it is important to call ProcessBlockData's build method to put information from the "default" and "initialize" arguments to a ProcessBlock derived class into the BlockData object's ConfigBlock. The the build method should usually be overloaded in a subclass derived from ProcessBlockData. This method would generally add Pyomo components such as variables, expressions, and constraints to the object. It is important for build() methods implimented in derived classes to call build() from the super class. Args: None Returns: None """ self._get_config_args()
[docs] def flowsheet(self): """ This method returns the components parent flowsheet object, i.e. the flowsheet component to which the model is attached. If the component has no parent flowsheet, the method returns None. Args: None Returns: Flowsheet object or None """ parent = self.parent_block() while True: if parent is None: return None if hasattr(parent, 'is_flowsheet') and parent.is_flowsheet(): return parent else: parent = parent.parent_block()
def _get_config_args(self): """ Get config arguments for this element and put them in the ConfigBlock """ if self._pb_configured: return self._pb_configured = True idx_map = self.parent_component()._idx_map # index map function try: idx = self.index() except: idx = None if idx_map is not None: idx = idx_map(idx) initialize = self.parent_component()._block_data_config_initialize if idx in initialize: kwargs = initialize[idx] else: kwargs = self.parent_component()._block_data_config_default self.config = self.CONFIG(kwargs)
[docs] def fix_initial_conditions(self, state="steady-state"): """This method fixes the initial conditions for dynamic models. Args: state : initial state to use for simulation (default = 'steady-state') Returns : None """ if state == 'steady-state': for obj in self.component_objects((Block, Disjunct), descend_into=True): # Try to fix material_accumulation @ first time point try: obj.material_accumulation[ obj.flowsheet().config.time.first(), ...].fix(0.0) except AttributeError: pass # Try to fix element_accumulation @ first time point try: obj.element_accumulation[ obj.flowsheet().config.time.first(), ...].fix(0.0) except AttributeError: pass # Try to fix energy_accumulation @ first time point try: obj.energy_accumulation[ obj.flowsheet().config.time.first(), ...].fix(0.0) except AttributeError: pass else: raise ValueError("Unrecognised value for argument 'state'. " "Valid values are 'steady-state'.")
[docs] def unfix_initial_conditions(self): """This method unfixed the initial conditions for dynamic models. Args: None Returns : None """ for obj in self.component_objects(Block, descend_into=True): # Try to unfix material_accumulation @ first time point try: obj.material_accumulation[ obj.flowsheet().config.time.first(), ...].unfix() except AttributeError: pass # Try to fix element_accumulation @ first time point try: obj.element_accumulation[ obj.flowsheet().config.time.first(), ...].unfix() except AttributeError: pass # Try to fix energy_accumulation @ first time point try: obj.energy_accumulation[ obj.flowsheet().config.time.first(), ...].unfix() except AttributeError: pass
def report(self, time_point=0, dof=False, ostream=None, prefix=""): time_point = float(time_point) if ostream is None: ostream = sys.stdout # Get DoF and model stats if dof: dof_stat = degrees_of_freedom(self) nv = number_variables(self) nc = number_activated_constraints(self) nb = number_activated_blocks(self) # Get components to report in performance section performance = self._get_performance_contents(time_point=time_point) # Get stream table stream_table = self._get_stream_table_contents(time_point=time_point) # Set model type output if hasattr(self, "is_flowsheet") and self.is_flowsheet: model_type = "Flowsheet" else: model_type = "Unit" # Write output max_str_length = 84 tab = " "*4 ostream.write("\n"+"="*max_str_length+"\n") lead_str = f"{prefix}{model_type} : {self.name}" trail_str = f"Time: {time_point}" mid_str = " "*(max_str_length-len(lead_str)-len(trail_str)) ostream.write(lead_str+mid_str+trail_str) if dof: ostream.write("\n"+"="*max_str_length+"\n") ostream.write(f"{prefix}{tab}Local Degrees of Freedom: {dof_stat}") ostream.write('\n') ostream.write(f"{prefix}{tab}Total Variables: {nv}{tab}" f"Activated Constraints: {nc}{tab}" f"Activated Blocks: {nb}") if performance is not None: ostream.write("\n"+"-"*max_str_length+"\n") ostream.write(f"{prefix}{tab}Unit Performance") ostream.write("\n"*2) if "vars" in performance.keys() and len(performance["vars"]) > 0: ostream.write(f"{prefix}{tab}Variables: \n\n") tabular_writer( ostream, prefix+tab, ((k, v) for k, v in performance["vars"].items()), ("Value", "Fixed", "Bounds"), lambda k, v: [ "{:#.5g}".format(value(v)), v.fixed, v.bounds]) if "exprs" in performance.keys() and len(performance["exprs"]) > 0: ostream.write("\n") ostream.write(f"{prefix}{tab}Expressions: \n\n") tabular_writer( ostream, prefix+tab, ((k, v) for k, v in performance["exprs"].items()), ("Value",), lambda k, v: [ "{:#.5g}".format(value(v))]) if ("params" in performance.keys() and len(performance["params"]) > 0): ostream.write("\n") ostream.write(f"{prefix}{tab}Parameters: \n\n") tabular_writer( ostream, prefix+tab, ((k, v) for k, v in performance["params"].items()), ("Value", "Mutable"), lambda k, v: [value(v), not v.is_constant()]) if stream_table is not None: ostream.write("\n"+"-"*max_str_length+"\n") ostream.write(f"{prefix}{tab}Stream Table") ostream.write('\n') ostream.write( textwrap.indent( stream_table_dataframe_to_string(stream_table), prefix+tab)) ostream.write("\n"+"="*max_str_length+"\n") def _get_performance_contents(self, time_point): return None def _get_stream_table_contents(self, time_point): return None def _setup_dynamics(self): """ This method automates the setting of the dynamic flag and time domain for unit models. Performs the following: 1) Determines if this is a top level flowsheet 2) Gets dynamic flag from parent if not top level, or checks validity of argument provided 3) Checks has_holdup flag if present and dynamic = True Args: None Returns: None """ # Get parent object if hasattr(self.parent_block(), "config"): # Parent block has a config block, so use this parent = self.parent_block() else: # Use parent flowsheet try: parent = self.flowsheet() except ConfigurationError: raise DynamicError('{} has no parent flowsheet from which to ' 'get dynamic argument. Please provide a ' 'value for this argument when constructing ' 'the unit.' .format(self.name)) # Check the dynamic flag, and retrieve if necessary if self.config.dynamic == useDefault: # Get flag from parent flowsheet try: self.config.dynamic = parent.config.dynamic except AttributeError: # No flowsheet, raise exception raise DynamicError('{} parent flowsheet has no dynamic ' 'argument. Please provide a ' 'value for this argument when constructing ' 'the unit.' .format(self.name)) # Check for case when dynamic=True, but parent dynamic=False if (self.config.dynamic and not parent.config.dynamic): raise DynamicError('{} trying to declare a dynamic model within ' 'a steady-state flowsheet. This is not ' 'supported by the IDAES framework. Try ' 'creating a dynamic flowsheet instead, and ' 'declaring some models as steady-state.' .format(self.name)) # Set and validate has_holdup argument if self.config.has_holdup == useDefault: # Default to same value as dynamic flag self.config.has_holdup = self.config.dynamic elif self.config.has_holdup is False: if self.config.dynamic is True: # Dynamic model must have has_holdup = True raise ConfigurationError( "{} invalid arguments for dynamic and has_holdup. " "If dynamic = True, has_holdup must also be True " "(was False)".format(self.name)) def _get_property_package(self): """ This method gathers the necessary information about the property package to be used in the control volume block. If a property package has not been provided by the user, the method searches up the model tree until it finds an object with the 'default_property_package' attribute and uses this package for the control volume block. The method also gathers any default construction arguments specified for the property package and combines these with any arguments specified by the user for the control volume block (user specified arguments take priority over defaults). Args: None Returns: None """ # Get property_package block if not provided in arguments parent = self.parent_block() if self.config.property_package == useDefault: # Try to get property_package from parent try: if parent.config.property_package in [None, useDefault]: parent.config.property_package = \ self._get_default_prop_pack() self.config.property_package = parent.config.property_package except AttributeError: self.config.property_package = self._get_default_prop_pack() # Check for any flowsheet level build arguments for k in self.config.property_package.config.default_arguments: if k not in self.config.property_package_args: self.config.property_package_args[k] = \ self.config.property_package.config.default_arguments[k] def _get_default_prop_pack(self): """ This method is used to find a default property package defined at the flowsheet level if a package is not provided as an argument when instantiating the control volume block. Args: None Returns: None """ parent = self.flowsheet() while True: if parent is None: raise ConfigurationError( '{} no property package provided and ' 'no default defined by parent flowsheet(s).' .format(self.name)) elif parent.config.default_property_package is not None: _log.info('{} Using default property package' .format(self.name)) return parent.config.default_property_package parent = parent.flowsheet() def _get_indexing_sets(self): """ This method collects all necessary indexing sets from property parameter block and makes references to these for use within the control volume block. Collected indexing sets are phase_list and component_list. Args: None Returns: None """ # Check for phase list(s) if not hasattr(self.config.property_package, "phase_list"): raise PropertyPackageError( '{} property_package provided does not ' 'contain a phase_list. ' 'Please contact the developer of the property package.' .format(self.name)) # Check for component list(s) if not hasattr(self.config.property_package, "component_list"): raise PropertyPackageError( '{} property_package provided does not ' 'contain a component_list. ' 'Please contact the developer of the property package.' .format(self.name)) def _get_reaction_package(self): """ This method gathers the necessary information about the reaction package to be used in the control volume block (if required). If a reaction package has been provided by the user, the method gathers any default construction arguments specified for the reaction package and combines these with any arguments specified by the user for the control volume block (user specified arguments take priority over defaults). Args: None Returns: None """ if self.config.reaction_package is not None: # Check for any flowsheet level build arguments for k in self.config.reaction_package.config.default_arguments: if k not in self.config.reaction_package_args: self.config.reaction_package_args[k] = \ self.config.reaction_package.config.default_arguments[k]