ccp.State

ccp.State#

class ccp.State(*args, **kwargs)#

A thermodynamic state.

This class is inherited from CP.AbstractState. Some extra functionality has been added.

Creates a state from fluid composition and two properties. Properties can be floats (SI units are considered) or pint quantities.

Parameters:

pfloat, pint.Quantity: Pressure
Tfloat, pint.Quantity: Temperature
hfloat, pint.Quantity: Enthalpy
sfloat, pint.Quantity: Entropy
rhofloat, pint.Quantity: Specific mass
fluiddict: Dictionary with constituent and composition (mole fraction). (e.g.: fluid={‘Oxygen’: 0.2096, ‘Nitrogen’: 0.7812, ‘Argon’: 0.0092})
EOSstr, optional: String with REFPROP, HEOS, PR or SRK. Default is set in ccp.config.EOS
phasestr, None or False, optional: String with phase information. Options are: - “liquid” - “gas” - “two_phase” - “supercritical_liquid” - “supercritical_gas” - “supercritical” Default is None: the first flash lets REFPROP/CoolProp determine the phase (a stability analysis that dominates the flash cost) and, when ccp.config.DEFAULT_PHASE is set (default “gas”), that phase is imposed for the later (p, T), (rho, T) and (rho, s) flashes if imposing it reproduces the resolved density. States derived from this one by the point solvers (discharge, isentropic and dummy states) inherit the imposed phase and solve every flash single phase, which is where the speed-up comes from. A general update with (p, h), (p, s) or (h, s) inputs stays an equilibrium flash, so a state throttled into the phase envelope resolves to the two-phase state. Pass phase=False to never impose a phase on this state, or set ccp.config.DEFAULT_PHASE = None to restore the legacy behaviour globally.

Returns:

stateccp.State

Examples

>>> import ccp
>>> Q_ = ccp.Q_
>>> fluid = {'Oxygen': 0.2096, 'Nitrogen': 0.7812, 'Argon': 0.0092}
>>> s = ccp.State(p=101008, T=273, fluid=fluid)
>>> s.rho()
<Quantity(1.28939426, 'kilogram / meter ** 3')>
>>> # Using pint quantities
>>> s = ccp.State(fluid=fluid, p=Q_(1, 'atm'), T=Q_(0, 'degC'))
>>> s.h()
<Quantity(273291.7, 'joule / kilogram')>

Methods

T(units=None)#

Temperature in Kelvin.

Returns:

Tpint.Quantity: Temperature (Kelvin).

T_critical(units=None)#

Critical Temperature in K.

Returns:

T_criticalpint.Quantity: Critical temperature (degK).

__init__(self, arg0: str, arg1: str, /) → None#

conductivity(units=None)#

Thermal conductivity (W/m/K).

Returns:

conductivitypint.Quantity: Thermal conductivity (W/m/K).

cp(units=None)#

Specific heat at constant pressure joule/(kilogram kelvin).

Returns:

cppint.Quantity: Specific heat at constant pressure joule/(kilogram kelvin).

cv(units=None)#

Specific heat at constant volume joule/(kilogram kelvin).

Returns:

cvpint.Quantity: Specific heat at constant volume joule/(kilogram kelvin).

dTdp_s(units=None)#

(dT / dp)s

First partial derivative of temperature related to pressure with constant entropy.

classmethod define(p=None, T=None, h=None, s=None, rho=None, fluid=None, EOS=None, **kwargs)#

Constructor for state.

Creates a state from fluid composition and two properties. Properties can be floats (SI units are considered) or pint quantities.

Parameters:

pfloat, pint.Quantity: Pressure
Tfloat, pint.Quantity: Temperature
hfloat, pint.Quantity: Enthalpy
sfloat, pint.Quantity: Entropy
rhofloat, pint.Quantity: Specific mass
fluiddict: Dictionary with constituent and composition. (e.g.: fluid={‘Oxygen’: 0.2096, ‘Nitrogen’: 0.7812, ‘Argon’: 0.0092}) String with REFPROP, HEOS, PR or SRK. Default is set in ccp.config.EOS

Returns:

stateccp.State

Examples

>>> import ccp
>>> Q_ = ccp.Q_
>>> fluid = {'Oxygen': 0.2096, 'Nitrogen': 0.7812, 'Argon': 0.0092}
>>> s = ccp.State.define(p=101008, T=273, fluid=fluid)
>>> s.rho()
<Quantity(1.28939426, 'kilogram / meter ** 3')>
>>> # Using pint quantities
>>> s = ccp.State.define(fluid=fluid, p=Q_(1, 'atm'), T=Q_(0, 'degC'))
>>> s.h()
<Quantity(273291.7, 'joule / kilogram')>

dpdv_s(units=None)#: Partial derivative of pressure to spec. volume with const. entropy.

gas_constant(units=None)#

Gas constant in joule / (mol kelvin).

Returns:

gas_constantpint.Quantity: Gas constant (joule / (mol kelvin).

get_coolprop_state()#: Return a CoolProp state object.

h(units=None)#

Specific Enthalpy (joule/kilogram).

Returns:

hpint.Quantity: Enthalpy (joule/kilogram).

kT()#

Isentropic temperature exponent (dimensionless).

Returns:

kTpint.Quantity: Isentropic temperature exponent (dimensionless).

kinematic_viscosity(units=None)#

Kinematic viscosity in m²/s.

Returns:

kinematic_viscositypint.Quantity: Kinematic viscosity (m²/s)

kv()#

Isentropic volume exponent (dimensionless).

Returns:

kvpint.Quantity: Isentropic volume exponent (dimensionless).

molar_mass(units=None)#

Molar mass in kg/mol.

Returns:

molar_masspint.Quantity: Molar mass (kg/mol).

p(units=None)#

Pressure in Pascal.

Returns:

ppint.Quantity: Pressure (pascal).

p_critical(units=None)#

Critical Pressure in Pa.

Returns:

p_criticalpint.Quantity: Critical pressure (Pa).

phase_is_stable()#

Check the imposed phase against an unconstrained flash.

Re-flashes the state at its current (p, T) without the imposed phase and compares densities. Returns True when no phase is imposed, when the unconstrained flash reproduces the density, or when the unconstrained flash fails (the check is then inconclusive). Returns False when the imposed root is metastable, i.e. the (p, T) point lies inside the phase envelope or on the other phase. The state is left unchanged (the imposed phase is restored).

plot_envelope(T_units='degK', p_units='Pa', dew_point_margin=20, fig=None, **kwargs)#

Plot phase envelope.

Plots the phase envelope and dew point limit.

Parameters:

T_unitsstr: Temperature units. Default is ‘degK’.
p_unitsstr: Pressure units. Default is ‘Pa’.
dew_point_marginfloat: Dew point margin. Default is 20 degK (from API). Unit is the same as T_units.
figplotly.graph_objects.Figure, optional: The figure object with the rotor representation.

Returns:

figplotly.graph_objects.Figure: The figure object with the rotor representation.

plot_point(T_units='degK', p_units='Pa', fig=None, **kwargs)#

Plot point.

Plot point in the given figure. Function will check for axis units and plot the point accordingly.

Parameters:

T_unitsstr: Temperature units. Default is ‘degK’.
p_unitsstr: Pressure units. Default is ‘Pa’.
figplotly.graph_objects.Figure, optional: The figure object with the rotor representation.
kwargsdict: Dictionary that will be passed to go.Scatter method.

Returns:

figplotly.graph_objects.Figure: The figure object with the rotor representation.

rho(units=None)#

Specific mass (kilogram/m**3).

Returns:

rhopint.Quantity: Specific mass (kilogram/m**3).

s(units=None)#

Specific entropy (per unit of mass).

Returns:

spint.Quantity: Entropy (joule/(kelvin kilogram)).

classmethod single_phase_solver()#

Let the imposed phase drive every flash while the block runs.

Used by the discharge closures of ccp.Point: a compression from a single-phase suction moves away from the dew line, so the single-phase root is the physical one and the (p, h), (p, s) and (h, s) flashes can skip the phase-stability analysis (see _solve_T_at_p()). Not used for general state updates, where a target inside the phase envelope must resolve to the equilibrium two-phase state.

speed_sound(units=None)#

Speed of sound - Eq. 8.1 from P. Nederstigt - Real Gas Thermodynamics.

Returns:

speed_soundpint.Quantity: Speed of sound (m/s).

update(p=None, T=None, rho=None, h=None, s=None, phase=None, **kwargs)#

Update the state.

This method simplifies the state update. Only keyword arguments are required to update.

Parameters:

pfloat, pint.Quantity: Pressure (Pa).
Tfloat, pint.Quantity: Temperature (degK).
rhofloat, pint.Quantity: Specific mass (kg/m**3).
hfloat, pint.Quantity: Enthalpy (J/kg).
sfloat, pint.Quantity: Entropy (J/(kg*degK)).
phasestr, optional: String with phase information. Options are: - “liquid” - “gas” - “two_phase” - “supercritical_liquid” - “supercritical_gas” - “supercritical” Default is the phase defined in the state initialization.

v(units=None)#

Specific volume (m**3/kilogram).

Returns:

vpint.Quantity: Specific volume (m**3/kilogram).

viscosity(units=None)#

Viscosity in pascal second.

Returns:

viscositypint.Quantity: Viscosity (pascal second)

z(units=None)#

Compressibility (dimensionless).

Returns:

zpint.Quantity: Compressibility (dimensionless).

Attributes

`Bvirial`
`Cvirial`
`PIP`
`Prandtl`
`Q`
`Qmass`
`T_reducing`
`Tmax`
`Tmin`
`Ttriple`
`acentric_factor`
`all_critical_points`
`alpha0`
`alphar`
`apply_simple_mixing_rule`
`available_in_high_level`
`backend_name`
`build_options_json`
`build_phase_envelope`
`build_spinodal`
`change_EOS`
`chemical_potential`
`clear`
`compressibility_factor`
`conductivity_contributions`
`conformal_state`
`cp0mass`
`cp0molar`
`cpmass`
`cpmolar`
`criticality_contour_values`
`cvmass`
`cvmolar`
`d2alpha0_dDelta2`
`d2alpha0_dDelta_dTau`
`d2alpha0_dTau2`
`d2alphar_dDelta2`
`d2alphar_dDelta_dTau`
`d2alphar_dTau2`
`d3alpha0_dDelta2_dTau`
`d3alpha0_dDelta3`
`d3alpha0_dDelta_dTau2`
`d3alpha0_dTau3`
`d3alphar_dDelta2_dTau`
`d3alphar_dDelta3`
`d3alphar_dDelta_dTau2`
`d3alphar_dTau3`
`d4alphar_dDelta2_dTau2`
`d4alphar_dDelta3_dTau`
`d4alphar_dDelta4`
`d4alphar_dDelta_dTau3`
`d4alphar_dTau4`
`dBvirial_dT`
`dCvirial_dT`
`dalpha0_dDelta`
`dalpha0_dTau`
`dalphar_dDelta`
`dalphar_dTau`
`delta`
`dipole_moment`
`fast_evaluate`
`first_partial_deriv`
`first_saturation_deriv`
`first_two_phase_deriv`
`first_two_phase_deriv_splined`
`fluid_names`
`fluid_param_string`
`fugacity`
`fugacity_coefficient`
`fundamental_derivative_of_gas_dynamics`
`get_binary_interaction_double`
`get_binary_interaction_string`
`get_fluid_constant`
`get_fluid_parameter_double`
`get_mass_fractions`
`get_mole_fractions`
`get_phase_envelope_data`
`get_reducing_state`
`get_spinodal_data`
`get_state`
`gibbsmass`
`gibbsmass_excess`
`gibbsmolar`
`gibbsmolar_excess`
`gibbsmolar_residual`
`has_melting_line`
`helmholtzmass`
`helmholtzmass_excess`
`helmholtzmolar`
`helmholtzmolar_excess`
`hmass`
`hmass_excess`
`hmass_idealgas`
`hmolar`
`hmolar_excess`
`hmolar_idealgas`
`hmolar_residual`
`ideal_curve`
`isobaric_expansion_coefficient`
`isothermal_compressibility`
`keyed_output`
`melting_line`
`mole_fractions_liquid`
`mole_fractions_liquid_double`
`mole_fractions_vapor`
`mole_fractions_vapor_double`
`name`
`neff`
`p_triple`
`phase`
`pmax`
`rhomass`
`rhomass_critical`
`rhomass_reducing`
`rhomolar`
`rhomolar_critical`
`rhomolar_reducing`
`saturated_liquid_keyed_output`
`saturated_vapor_keyed_output`
`saturation_ancillary`
`second_partial_deriv`
`second_saturation_deriv`
`second_two_phase_deriv`
`set_T`
`set_binary_interaction_double`
`set_binary_interaction_string`
`set_cubic_alpha_C`
`set_fluid_parameter_double`
`set_mass_fractions`
`set_mole_fractions`
`set_volu_fractions`
`smass`
`smass_excess`
`smass_idealgas`
`smolar`
`smolar_excess`
`smolar_idealgas`
`smolar_residual`
`specify_phase`
`surface_tension`
`tangent_plane_distance`
`tau`
`trivial_keyed_output`
`true_critical_point`
`umass`
`umass_excess`
`umass_idealgas`
`umolar`
`umolar_excess`
`umolar_idealgas`
`unspecify_phase`
`update_QT_pure_superanc`
`update_with_guesses`
`using_mass_fractions`
`using_mole_fractions`
`using_volu_fractions`
`viscosity_contributions`
`volumemass_excess`
`volumemolar_excess`

ccp.State

Contents

ccp.State#