Thermo

class thermosteam.Thermo(chemicals, mixture=None, Gamma=<class 'thermosteam.equilibrium.activity_coefficients.DortmundActivityCoefficients'>, Phi=<class 'thermosteam.equilibrium.fugacity_coefficients.IdealFugacityCoefficients'>, PCF=<class 'thermosteam.equilibrium.poyinting_correction_factors.IdealPoyintingCorrectionFactors'>, cache=None)[source]

Create a Thermo object that defines a thermodynamic property package

Parameters

chemicals (Chemicals or Iterable[str]) – Pure component chemical data.
mixture (Mixture, optional) – Calculates mixture properties.
Gamma (ActivityCoefficients subclass, optional) – Class for computing activity coefficients.
Phi (FugacityCoefficients subclass, optional) – Class for computing fugacity coefficients.
PCF (PoyntingCorrectionFactor subclass, optional) – Class for computing poynting correction factors.
cache (optional) – Whether or not to use cached chemicals.

Examples

Create a property package for water and ethanol:

>>> import thermosteam as tmo
>>> thermo = tmo.Thermo(['Ethanol', 'Water'], cache=True)
>>> thermo
Thermo(chemicals=CompiledChemicals([Ethanol, Water]), mixture=Mixture(rule='ideal mixing', ..., include_excess_energies=False), Gamma=DortmundActivityCoefficients, Phi=IdealFugacityCoefficients, PCF=IdealPoyintingCorrectionFactors)
>>> thermo.show() # May be easier to read
Thermo(
    chemicals=CompiledChemicals([Ethanol, Water]),
    mixture=Mixture(
        rule='ideal mixing', ...
        include_excess_energies=False
    ),
    Gamma=DortmundActivityCoefficients,
    Phi=IdealFugacityCoefficients,
    PCF=IdealPoyintingCorrectionFactors
)

Note that the Dortmund-UNIFAC is the default activity coefficient model. The ideal-equilibrium property package (which assumes a value of 1 for all activity coefficients) is also available:

>>> ideal = thermo.ideal()
>>> ideal.show()
Thermo(
    chemicals=CompiledChemicals([Ethanol, Water]),
    mixture=Mixture(
        rule='ideal mixing', ...
        include_excess_energies=False
    ),
    Gamma=IdealActivityCoefficients,
    Phi=IdealFugacityCoefficients,
    PCF=IdealPoyintingCorrectionFactors
)

Thermodynamic equilibrium results are affected by the choice of property package:

>>> # Ideal
>>> tmo.settings.set_thermo(ideal)
>>> stream = tmo.Stream('stream', Water=100, Ethanol=100)
>>> stream.vle(T=361, P=101325)
>>> stream.show()
MultiStream: stream
 phases: ('g', 'l'), T: 361 K, P: 101325 Pa
 flow (kmol/hr): (g) Ethanol  32.2
                     Water    17.3
                 (l) Ethanol  67.8
                     Water    82.7
>>> # Modified Roult's law:
>>> tmo.settings.set_thermo(thermo)
>>> stream = tmo.Stream('stream', Water=100, Ethanol=100)
>>> stream.vle(T=360, P=101325)
>>> stream.show()
MultiStream: stream
 phases: ('g', 'l'), T: 360 K, P: 101325 Pa
 flow (kmol/hr): (g) Ethanol  100
                     Water    100

Thermodynamic property packages are pickleable:

>>> tmo.utils.save(thermo, "Ethanol-Water Property Package")
>>> thermo = tmo.utils.load("Ethanol-Water Property Package")
>>> thermo.show()
Thermo(
    chemicals=CompiledChemicals([Ethanol, Water]),
    mixture=Mixture(
        rule='ideal mixing', ...
        include_excess_energies=False
    ),
    Gamma=DortmundActivityCoefficients,
    Phi=IdealFugacityCoefficients,
    PCF=IdealPoyintingCorrectionFactors
)

chemicals

Pure component chemical data.

Type: Chemicals or Iterable[str]

mixture

Calculates mixture properties.

Type: Mixture, optional

Gamma

Class for computing activity coefficients.

Type: ActivityCoefficients subclass, optional

Phi

Class for computing fugacity coefficients.

Type: FugacityCoefficients subclass, optional

PCF

Class for computing poynting correction factors.

Type: PoyntingCorrectionFactor subclass, optional

ideal()[source]: Ideal thermodynamic property package.

as_chemical(chemical)[source]

Return chemical as a Chemical object.

Parameters: chemical (str or Chemical) – Name of chemical being retrieved.

Examples

>>> import thermosteam as tmo
>>> thermo = tmo.Thermo(['Ethanol', 'Water'], cache=True)
>>> thermo.as_chemical('Water') is thermo.chemicals.Water
True
>>> thermo.as_chemical('Octanol') # Chemical not defined, so it will be created
Chemical('Octanol')

subgroup(IDs)[source]

Create a Thermo object from a subset of chemicals.

Parameters: IDs (Iterable[str]) – Names of chemicals.

Examples

>>> import thermosteam as tmo
>>> thermo = tmo.Thermo(['Ethanol', 'Water'], cache=True)
>>> thermo_water = thermo.subgroup(['Water'])
>>> thermo_water.show()
Thermo(
    chemicals=CompiledChemicals([Water]),
    mixture=Mixture(
        rule='ideal mixing', ...
        include_excess_energies=False
    ),
    Gamma=DortmundActivityCoefficients,
    Phi=IdealFugacityCoefficients,
    PCF=IdealPoyintingCorrectionFactors
)