idaes.property_models package

Subpackages

• idaes.property_models.activity_coeff_models package
  • Submodules
  • idaes.property_models.activity_coeff_models.BTX_activity_coeff_VLE module
  • idaes.property_models.activity_coeff_models.activity_coeff_prop_pack module
• idaes.property_models.examples package
  • Submodules
  • idaes.property_models.examples.methane_combustion_ideal module
  • idaes.property_models.examples.saponification_reactions module
  • idaes.property_models.examples.saponification_thermo module
• idaes.property_models.iapws95_lib package

Submodules

idaes.property_models.iapws95 module

IDAES IAPWS-95 Steam properties

Dropped all critical enhancments and non-analytic terms ment to imporve accruacy near the critical point. These tend to cause singularities in the equations, and it is assumend that we will try to avoid operating very close to the critical point.

References: (some of this is only used in the C++ part)

International Association for the Properties of Water and Steam (2016).

IAPWS R6-95 (2016), “Revised Release on the IAPWS Formulation 1995 for the Properties of Ordinary Water Substance for General Scientific Use,” URL: http://iapws.org/relguide/IAPWS95-2016.pdf

Wagner, W., A. Pruss (2002). “The IAPWS Formulation 1995 for the

Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use.” J. Phys. Chem. Ref. Data, 31, 387-535.

Wagner, W. et al. (2000). “The IAPWS Industrial Formulation 1997 for the

Thermodynamic Properties of Water and Steam,” ASME J. Eng. Gas Turbines and Power, 122, 150-182.

Akasaka, R. (2008). “A Reliable and Useful Method to Determine the Saturation

State from Helmholtz Energy Equations of State.” Journal of Thermal Science and Technology, 3(3), 442-451.

International Association for the Properties of Water and Steam (2011).

IAPWS R15-11, “Release on the IAPWS Formulation 2011 for the Thermal Conductivity of Ordinary Water Substance,” URL: http://iapws.org/relguide/ThCond.pdf

International Association for the Properties of Water and Steam (2008).

IAPWS R12-08, “Release on the IAPWS Formulation 2008 for the Viscosity of Ordinary Water Substance,” URL: http://iapws.org/relguide/visc.pdf

class idaes.property_models.iapws95.Iapws95ParameterBlock(*args, **kwargs)

Parameters:

• rule (function) – A rule function or None. Default rule calls build().
• concrete (bool) – If True, make this a toplevel model. Default - False.
• ctype (str) – Pyomo ctype of the block. Default - “Block”
• default (dict) –

  Default ProcessBlockData config

  Keys

  default_arguments

  Default arguments to use with Property Package

  phase_presentation

  Set the way phases are presented to models. The MIX option appears to the framework to be a mixed phase containing liquid and/or vapor. The mixed option can simplify calculations at the unit model level since it can be treated as a single phase, but unit models such as flash vessels will not be able to treate the phases indepedently. The LG option presents as two sperate phases to the framework. The L or G options can be used if it is known for sure that only one phase is present. default - PhaseType.MIX Valid values: { PhaseType.MIX - Present a mixed phase with liquid and/or vapor, PhaseType.LG - Present a liquid and vapor phase, PhaseType.L - Assume only liquid can be present, PhaseType.G - Assume only vapor can be present}

  state_vars

  The set of state variables to use. Depending on the use, one state variable set or another may be better computationally. Usually pressure and enthalpy are the best choice because they are well behaved during a phase change. default - StateVars.PH Valid values: { StateVars.PH - Pressure-Enthalpy, StateVars.TPX - Temperature-Pressure-Quality}

• initialize (dict) – ProcessBlockData config for individual elements. Keys are BlockData indexes and values are dictionaries described under the “default” argument above.
• idx_map (function) – Function to take the index of a BlockData element and return the index in the initialize dict from which to read arguments. This can be provided to overide the default behavior of matching the BlockData index exactly to the index in initialize.

Returns:

(Iapws95ParameterBlock) New instance

class idaes.property_models.iapws95.Iapws95ParameterBlockData(component)

build()

General build method for PropertyParameterBlocks. Inheriting models should call super().build.

Parameters:None – Returns:None

classmethod define_metadata(obj)

Set all the metadata for properties and units.

This method should be implemented by subclasses. In the implementation, they should set information into the object provided as an argument.

Parameters:pcm (PropertyClassMetadata) – Add metadata to this object. Returns:None

class idaes.property_models.iapws95.Iapws95StateBlock(*args, **kwargs)

This is some placeholder doc.

Parameters:

• rule (function) – A rule function or None. Default rule calls build().
• concrete (bool) – If True, make this a toplevel model. Default - False.
• ctype (str) – Pyomo ctype of the block. Default - “Block”
• default (dict) –

  Default ProcessBlockData config

  Keys

  parameters

  A reference to an instance of the Property Parameter Block associated with this property package.

  defined_state

  Flag indicating whether the state should be considered fully defined, and thus whether constraints such as sum of mass/mole fractions should be included, default - False. Valid values: { True - state variables will be fully defined, False - state variables will not be fully defined.}

  has_phase_equilibrium

  Flag indicating whether phase equilibrium constraints should be constructed in this state block, default - True. Valid values: { True - StateBlock should calculate phase equilibrium, False - StateBlock should not calculate phase equilibrium.}

• initialize (dict) – ProcessBlockData config for individual elements. Keys are BlockData indexes and values are dictionaries described under the “default” argument above.
• idx_map (function) – Function to take the index of a BlockData element and return the index in the initialize dict from which to read arguments. This can be provided to overide the default behavior of matching the BlockData index exactly to the index in initialize.

Returns:

(Iapws95StateBlock) New instance

class idaes.property_models.iapws95.Iapws95StateBlockData(component)

This is a property package for calculating thermophysical properties of water

build(*args)

Callable method for Block construction

define_display_vars()

Method used to specify components to use to generate stream tables and other outputs. Defaults to define_state_vars, and developers should overload as required.

define_state_vars()

Method that returns a dictionary of state variables used in property package. Implement a placeholder method which returns an Exception to force users to overload this.

get_energy_density_terms(p)

Method which returns a valid expression for enthalpy density to use in the energy balances.

get_enthalpy_flow_terms(p)

Method which returns a valid expression for enthalpy flow to use in the energy balances.

get_material_density_terms(p, j)

Method which returns a valid expression for material density to use in the material balances .

get_material_flow_terms(p, j)

Method which returns a valid expression for material flow to use in the material balances.

class idaes.property_models.iapws95.PhaseType

Ways to present phases to the framework

class idaes.property_models.iapws95.StateVars

State variable set options

idaes.property_models.iapws95.htpx(T, P=None, x=None)

Convenience function to calculate steam enthalpy from temperature and either pressure or vapor fraction. This function can be used for inlet streams and initialization where temperature is known instead of enthalpy.

Parameters:

• T – Temperature [K]
• P – Pressure [Pa], None if saturated steam
• x – Vapor fraction [mol vapor/mol total], None if superheated or subcooled

Returns:

Total molar enthalpy [J/mol].

idaes.property_models.iapws95.iapws95_available()

Make sure the compiled IAPWS-95 functions are available. Yes, in Windows the .so extention is still used.