idaes.property_models.iapws95 package

Submodules

idaes.property_models.iapws95.iapws95_wrap_ph 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.iapws95_wrap_ph.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

• 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.iapws95_wrap_ph.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.iapws95_wrap_ph.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.iapws95_wrap_ph.Iapws95StateBlockData(component)

This is a property package for calcuating thermophysical properties of water

build(*args)

Callable method for Block construction

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_enthalpy_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.

idaes.property_models.iapws95.iapws95_wrap_ph.htpx(T, P=None, x=None)

Conveneince 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 instread of enthalpy. :param T: Temperature [K] :param P: Pressure [Pa], None if saturated steam :param x: Vapor fraction [mol vapor/mol total], None if superheated or subcooled

Returns:Molar enthalpy [J/mol].