# -*- coding: utf-8
"""Module for fluid property mixture routines.
This file is part of project TESPy (github.com/oemof/tespy). It's copyrighted
by the contributors recorded in the version control history of the file,
available from its original location
tespy/tools/fluid_properties/mixtures.py
SPDX-License-Identifier: MIT
"""
import CoolProp as CP
import numpy as np
from tespy.tools.global_vars import gas_constants
from .helpers import _is_larger_than_precision
from .helpers import calc_molar_mass_mixture
from .helpers import get_molar_fractions
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def h_mix_pT_ideal(p=None, T=None, fluid_data=None, **kwargs):
molar_fractions = get_molar_fractions(fluid_data)
h = 0
for fluid, data in fluid_data.items():
if _is_larger_than_precision(data["mass_fraction"]):
pp = p * molar_fractions[fluid]
h += data["wrapper"].h_pT(pp, T) * data["mass_fraction"]
return h
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def h_mix_pT_ideal_cond(p=None, T=None, fluid_data=None, **kwargs):
water_alias = _water_in_mixture(fluid_data)
if water_alias:
water_alias = next(iter(water_alias))
mass_fractions_gas, molar_fraction_gas, mass_liquid, molar_liquid = cond_check(p, T, fluid_data, water_alias)
if not _is_larger_than_precision(mass_liquid):
return h_mix_pT_ideal(p, T, fluid_data, **kwargs)
h = 0
for fluid, data in fluid_data.items():
if _is_larger_than_precision(data["mass_fraction"]):
if fluid == water_alias:
h += fluid_data[water_alias]["wrapper"].h_QT(0, T) * mass_liquid
h += fluid_data[water_alias]["wrapper"].h_QT(1, T) * mass_fractions_gas[fluid] * (1 - mass_liquid)
else:
pp = p * molar_fraction_gas[fluid]
h += data["wrapper"].h_pT(pp, T) * mass_fractions_gas[fluid] * (1 - mass_liquid)
return h
else:
return h_mix_pT_ideal(p, T, fluid_data, **kwargs)
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def h_mix_pT_forced_gas(p, T, fluid_data, **kwargs):
molar_fractions = get_molar_fractions(fluid_data)
h = 0
for fluid, data in fluid_data.items():
if _is_larger_than_precision(data["mass_fraction"]):
pp = p * molar_fractions[fluid]
if fluid == "H2O" and pp >= data["wrapper"]._p_min:
if T <= data["wrapper"].T_sat(pp):
h += data["wrapper"].h_QT(1, T) * data["mass_fraction"]
else:
h += data["wrapper"].h_pT(pp, T) * data["mass_fraction"]
else:
h += data["wrapper"].h_pT(pp, T) * data["mass_fraction"]
return h
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def h_mix_pT_incompressible(p, T, fluid_data, **kwargs):
h = 0
for data in fluid_data.values():
if _is_larger_than_precision(data["mass_fraction"]):
h += data["wrapper"].h_pT(p, T) * data["mass_fraction"]
return h
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def s_mix_pT_ideal(p=None, T=None, fluid_data=None, **kwargs):
molar_fractions = get_molar_fractions(fluid_data)
s = 0
for fluid, data in fluid_data.items():
if _is_larger_than_precision(data["mass_fraction"]):
pp = p * molar_fractions[fluid]
s += data["wrapper"].s_pT(pp, T) * data["mass_fraction"]
return s
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def s_mix_pT_ideal_cond(p=None, T=None, fluid_data=None, **kwargs):
water_alias = _water_in_mixture(fluid_data)
if water_alias:
water_alias = next(iter(water_alias))
mass_fractions_gas, molar_fraction_gas, mass_liquid, molar_liquid = cond_check(p, T, fluid_data, water_alias)
if mass_liquid == 0:
return s_mix_pT_ideal(p, T, fluid_data, **kwargs)
s = 0
for fluid, data in fluid_data.items():
if _is_larger_than_precision(data["mass_fraction"]):
if fluid == water_alias:
s += fluid_data[water_alias]["wrapper"].s_QT(0, T) * mass_liquid
s += fluid_data[water_alias]["wrapper"].s_QT(1, T) * mass_fractions_gas[fluid] * (1 - mass_liquid)
else:
pp = p * molar_fraction_gas[fluid]
s += data["wrapper"].s_pT(pp, T) * mass_fractions_gas[fluid] * (1 - mass_liquid)
return s
else:
return s_mix_pT_ideal(p, T, fluid_data, **kwargs)
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def s_mix_pT_incompressible(p=None, T=None, fluid_data=None, **kwargs):
s = 0
for data in fluid_data.values():
if _is_larger_than_precision(data["mass_fraction"]):
s += data["wrapper"].s_pT(p, T) * data["mass_fraction"]
return s
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def v_mix_pT_ideal(p=None, T=None, fluid_data=None, **kwargs):
molar_fractions = get_molar_fractions(fluid_data)
d = 0
for fluid, data in fluid_data.items():
if _is_larger_than_precision(data["mass_fraction"]):
pp = p * molar_fractions[fluid]
d += data["wrapper"].d_pT(pp, T)
return 1 / d
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def v_mix_pT_ideal_cond(p=None, T=None, fluid_data=None, **kwargs):
water_alias = _water_in_mixture(fluid_data)
if water_alias:
water_alias = next(iter(water_alias))
mass_fractions_gas, molar_fraction_gas, mass_liquid, molar_liquid = cond_check(p, T, fluid_data, water_alias)
if mass_liquid == 0:
return v_mix_pT_ideal(p, T, fluid_data, **kwargs)
d = 0
for fluid, data in fluid_data.items():
if _is_larger_than_precision(data["mass_fraction"]):
if fluid == water_alias:
d += fluid_data[water_alias]["wrapper"].d_QT(0, T) * mass_liquid
d += fluid_data[water_alias]["wrapper"].d_QT(1, T) * (1 - mass_liquid)
else:
pp = p * molar_fraction_gas[fluid]
d += data["wrapper"].d_pT(pp, T) * (1 - mass_liquid)
return 1 / d
else:
return v_mix_pT_ideal(p, T, fluid_data, **kwargs)
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def v_mix_pT_incompressible(p=None, T=None, fluid_data=None, **kwargs):
v = 0
for data in fluid_data.values():
if _is_larger_than_precision(data["mass_fraction"]):
v += 1 / data["wrapper"].d_pT(p, T) * data["mass_fraction"]
return v
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def viscosity_mix_pT_ideal(p=None, T=None, fluid_data=None, **kwargs):
r"""
Calculate dynamic viscosity from pressure and temperature.
Parameters
----------
flow : list
Fluid property vector containing mass flow, pressure, enthalpy and
fluid composition.
T : float
Temperature T / K.
Returns
-------
visc : float
Dynamic viscosity visc / Pa s.
Note
----
Calculation for fluid mixtures.
.. math::
\eta_{mix}(p,T)=\frac{\sum_{i} \left( \eta(p,T,fluid_{i}) \cdot y_{i}
\cdot \sqrt{M_{i}} \right)}
{\sum_{i} \left(y_{i} \cdot \sqrt{M_{i}} \right)}\;
\forall i \in \text{fluid components}\\
y: \text{volume fraction}\\
M: \text{molar mass}
Reference: :cite:`Herning1936`.
"""
molar_fractions = get_molar_fractions(fluid_data)
a = 0
b = 0
for fluid, data in fluid_data.items():
if _is_larger_than_precision(data["mass_fraction"]):
bi = molar_fractions[fluid] * data["wrapper"]._molar_mass ** 0.5
b += bi
a += bi * data["wrapper"].viscosity_pT(p, T)
return a / b
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def viscosity_mix_pT_incompressible(p=None, T=None, fluid_data=None, **kwargs):
viscosity = 0
for data in fluid_data.values():
if _is_larger_than_precision(data["mass_fraction"]):
viscosity += data["wrapper"].viscosity_pT(p, T) * data["mass_fraction"]
return viscosity
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def exergy_chemical_ideal_cond(pamb, Tamb, fluid_data, Chem_Ex):
molar_fractions = get_molar_fractions(fluid_data)
water_alias = _water_in_mixture(fluid_data)
if water_alias:
water_alias = next(iter(water_alias))
_, molar_fractions_gas, _, molar_liquid = cond_check(
pamb, Tamb, fluid_data, water_alias
)
else:
molar_fractions_gas = molar_fractions
molar_liquid = 0
ex_cond = 0
ex_dry = 0
for fluid, x in molar_fractions_gas.items():
if x == 0:
continue
fluid_aliases = fluid_data[fluid]["wrapper"]._aliases
if molar_liquid > 0 and "water" in fluid_aliases:
y = [
Chem_Ex[k][2] for k in fluid_aliases if k in Chem_Ex
]
ex_cond += molar_liquid * y[0]
y = [Chem_Ex[k][3] for k in fluid_aliases if k in Chem_Ex]
ex_dry += x * y[0] + Tamb * gas_constants['uni'] * 1e-3 * x * np.log(x)
ex_chemical = ex_cond + ex_dry * (1 - molar_liquid)
ex_chemical *= 1 / calc_molar_mass_mixture(
fluid_data, molar_fractions
)
return ex_chemical * 1e3 # Data from Chem_Ex are in kJ / mol
def _water_in_mixture(fluid_data):
water_aliases = set(CP.CoolProp.get_aliases("H2O"))
return water_aliases & set([f for f in fluid_data if _is_larger_than_precision(fluid_data[f]["mass_fraction"])])
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def cond_check(p, T, fluid_data, water_alias):
"""Check if water is partially condensing in gaseous mixture.
Parameters
----------
y_i : dict
Mass specific fluid composition.
x_i : dict
Mole specific fluid composition.
p : float
Pressure of mass flow.
n : float
Molar mass flow.
T : float
Temperature of mass flow.
Returns
-------
tuple
Tuple containing gas phase mass specific and molar specific
compositions and overall liquid water mass fraction.
"""
molar_fractions = get_molar_fractions(fluid_data)
molar_fractions_gas = molar_fractions
mass_fractions_gas = {f: v["mass_fraction"] for f, v in fluid_data.items()}
water_mass_liquid = 0
water_molar_liquid = 0
if fluid_data[water_alias]["wrapper"]._is_below_T_critical(T):
p_sat = fluid_data[water_alias]["wrapper"].p_sat(T)
pp_water = p * molar_fractions[water_alias]
if p_sat < pp_water:
water_molar_gas = (1 - molar_fractions[water_alias]) / (p / p_sat - 1)
water_molar_liquid = molar_fractions[water_alias] - water_molar_gas
x_gas_sum = 1 - water_molar_liquid
molar_fractions_gas = {f: x / x_gas_sum for f, x in molar_fractions.items()}
molar_fractions_gas[water_alias] = water_molar_gas / x_gas_sum
water_mass_liquid = (
water_molar_liquid
* fluid_data[water_alias]["wrapper"]._molar_mass
/ calc_molar_mass_mixture(fluid_data, molar_fractions)
)
molar_mass_mixture = calc_molar_mass_mixture(fluid_data, molar_fractions_gas)
mass_fractions_gas = {
fluid: (
x / molar_mass_mixture
* fluid_data[fluid]["wrapper"]._molar_mass
)
for fluid, x in molar_fractions_gas.items()
}
return mass_fractions_gas, molar_fractions_gas, water_mass_liquid, water_molar_liquid
T_MIX_PH_REVERSE = {
"ideal": h_mix_pT_ideal,
"ideal-cond": h_mix_pT_ideal_cond,
"incompressible": h_mix_pT_incompressible
}
T_MIX_PS_REVERSE = {
"ideal": s_mix_pT_ideal,
"ideal-cond": s_mix_pT_ideal_cond,
"incompressible": s_mix_pT_incompressible
}
H_MIX_PT_DIRECT = {
"ideal": h_mix_pT_ideal,
"ideal-cond": h_mix_pT_ideal_cond,
"incompressible": h_mix_pT_incompressible,
"forced-gas": h_mix_pT_forced_gas
}
S_MIX_PT_DIRECT = {
"ideal": s_mix_pT_ideal,
"ideal-cond": s_mix_pT_ideal_cond,
"incompressible": s_mix_pT_incompressible
}
V_MIX_PT_DIRECT = {
"ideal": v_mix_pT_ideal,
"ideal-cond": v_mix_pT_ideal_cond,
"incompressible": v_mix_pT_incompressible
}
VISCOSITY_MIX_PT_DIRECT = {
"ideal": viscosity_mix_pT_ideal,
"ideal-cond": viscosity_mix_pT_ideal,
"incompressible": viscosity_mix_pT_incompressible
}
EXERGY_CHEMICAL = {
"ideal-cond": exergy_chemical_ideal_cond,
}