#!/usr/bin/python3
# -*- coding: utf-8 -*-
"""Pychemqt, Chemical Engineering Process simulator
Copyright (C) 2009-2025, Juan José Gómez Romera <jjgomera@gmail.com>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
Library with a wrapper class of iapws97 for IAPWS formulation
All the functionality is included in the main class:
* :class:`IAPWS97`: Stream definition using IAPWS-IF97 formulation valid \
for liquid water or steam
Direct access to normally used input parameters
* :class:`IAPWS97_PT`: Derivated class for direct P and T input
* :class:`IAPWS97_Ph`: Derivated class for direct P and h input
* :class:`IAPWS97_Ps`: Derivated class for direct P and s input
* :class:`IAPWS97_Px`: Derivated class for direct P and x input
* :class:`IAPWS97_Tx`: Derivated class for direct T and x input
API reference
-------------
"""
from iapws.iapws97 import IAPWS97 as IAPWS
from iapws._iapws import M, Tc, Pc, rhoc, Tt, Tb, Dipole, f_acent
from lib import unidades
from lib.thermo import ThermoWater
try:
from iapws import __doi__
except ImportError:
__doi__ = {}
__doi__["1"] = {
"autor": "Wagner, W., Cooper, J.R., Dittmann, A., Kijima, J., "
"Kretzschmar, H.-J., Kruse, A., Mareš, R., Oguchi, K., Sato,"
" H., Stöcker, I., Šifner, O., Takaishi, Y., Tanishita, I., "
"Trübenbach, J., Willkommen, T.",
"title": "The IAPWS Industrial Formulation 1997 for the Thermodynamic "
"Properties of Water and Steam",
"ref": "J. Eng. Gas Turbines & Power 122 (2000) 150-182",
"doi": "10.1115/1.483186"}
[docs]
class IAPWS97(ThermoWater):
"""Class to model a state for liquid water or steam with the IAPWS-IF97
Parameters
----------
T : float
Temperature [K]
P : float
Pressure [MPa]
h : float
Specific enthalpy [kJ/kg]
s : float
Specific entropy [kJ/kgK]
x : float
Vapor quality [-]
l : float, optional
Wavelength of light, for refractive index [nm]
Notes
-----
Definitions options:
* T, P: Not valid for two-phases region
* P, h
* P, s
* h, s
* T, x: Only for two-phases region
* P, x: Only for two-phases region
Returns
-------
The calculated instance has the following properties:
* P: Pressure [MPa]
* T: Temperature [K]
* g: Specific Gibbs free energy [kJ/kg]
* a: Specific Helmholtz free energy [kJ/kg]
* v: Specific volume [m³/kg]
* rho: Density [kg/m³]
* h: Specific enthalpy [kJ/kg]
* u: Specific internal energy [kJ/kg]
* s: Specific entropy [kJ/kg·K]
* cp: Specific isobaric heat capacity [kJ/kg·K]
* cv: Specific isochoric heat capacity [kJ/kg·K]
* Z: Compression factor [-]
* fi: Fugacity coefficient [-]
* f: Fugacity [MPa]
* gamma: Isoentropic exponent [-]
* alfav: Isobaric cubic expansion coefficient [1/K]
* xkappa: Isothermal compressibility [1/MPa]
* kappas: Adiabatic compresibility [1/MPa]
* alfap: Relative pressure coefficient [1/K]
* betap: Isothermal stress coefficient [kg/m³]
* joule: Joule-Thomson coefficient [K/MPa]
* deltat: Isothermal throttling coefficient [kJ/kg·MPa]
* region: Region
* v0: Ideal specific volume [m³/kg]
* u0: Ideal specific internal energy [kJ/kg]
* h0: Ideal specific enthalpy [kJ/kg]
* s0: Ideal specific entropy [kJ/kg·K]
* a0: Ideal specific Helmholtz free energy [kJ/kg]
* g0: Ideal specific Gibbs free energy [kJ/kg]
* cp0: Ideal specific isobaric heat capacity [kJ/kg·K]
* cv0: Ideal specific isochoric heat capacity [kJ/kg·K]
* w0: Ideal speed of sound [m/s]
* gamma0: Ideal isoentropic exponent [-]
* w: Speed of sound [m/s]
* mu: Dynamic viscosity [Pa·s]
* nu: Kinematic viscosity [m²/s]
* k: Thermal conductivity [W/m·K]
* alfa: Thermal diffusivity [m²/s]
* sigma: Surface tension [N/m]
* epsilon: Dielectric constant [-]
* n: Refractive index [-]
* Prandt: Prandtl number [-]
* Pr: Reduced Pressure [-]
* Tr: Reduced Temperature [-]
Examples
--------
Region 1, Table A3
>>> st = IAPWS97(T=300, P=3e6)
>>> "%0.9g %0.9g %0.9g" % (st.v, st.h.kJkg, st.u.kJkg)
'0.00100215168 115.331273 112.324818'
>>> "%0.9g %0.9g %0.9g" % (st.s.kJkgK, st.cp.kJkgK, st.w)
'0.392294792 4.17301218 1507.73921'
>>> st = IAPWS97(T=300, P=8e7)
>>> "%0.9g %0.9g %0.9g" % (st.v, st.h.kJkg, st.u.kJkg)
'0.000971180894 184.142828 106.448356'
>>> "%0.9g %0.9g %0.9g" % (st.s.kJkgK, st.cp.kJkgK, st.w)
'0.368563852 4.01008987 1634.69054'
>>> st = IAPWS97(T=500, P=3e6)
>>> "%0.9g %0.9g %0.9g" % (st.v, st.h.kJkg, st.u.kJkg)
'0.001202418 975.542239 971.934985'
>>> "%0.9g %0.9g %0.9g" % (st.s.kJkgK, st.cp.kJkgK, st.w)
'2.58041912 4.65580682 1240.71337'
Region 2, Table A6
>>> st = IAPWS97(T=300, P=3.5e3)
>>> "%0.9g %0.9g %0.9g" % (st.v, st.h.kJkg, st.u.kJkg)
'39.4913866 2549.91145 2411.6916'
>>> "%0.9g %0.9g %0.9g" % (st.s.kJkgK, st.cp.kJkgK, st.w)
'8.52238967 1.91300162 427.920172'
>>> st = IAPWS97(T=700, P=3.5e3)
>>> "%0.9g %0.9g %0.9g" % (st.v, st.h.kJkg, st.u.kJkg)
'92.3015898 3335.68375 3012.62819'
>>> "%0.9g %0.9g %0.9g" % (st.s.kJkgK, st.cp.kJkgK, st.w)
'10.1749996 2.08141274 644.289068'
>>> st = IAPWS97(T=700, P=3e7)
>>> "%0.9g %0.9g %0.9g" % (st.v, st.h.kJkg, st.u.kJkg)
'0.00542946619 2631.49474 2468.61076'
>>> "%0.9g %0.9g %0.9g" % (st.s.kJkgK, st.cp.kJkgK, st.w)
'5.17540298 10.3505092 480.386523'
Region 3, Table A10
>>> from iapws.iapws97 import _Region3
>>> st = _Region3(500, 650)
>>> "%0.9g %0.9g %0.9g" % (st["P"], st["h"], st["h"]-st["P"]*1000*st["v"])
'25.5837018 1863.43019 1812.26279'
>>> "%0.9g %0.9g %0.9g" % (st["s"], st["cp"], st["w"])
'4.05427273 13.8935717 502.005554'
>>> st = _Region3(200, 650)
>>> "%0.9g %0.9g %0.9g" % (st["P"], st["h"], st["h"]-st["P"]*1000*st["v"])
'22.2930643 2375.12401 2263.65868'
>>> "%0.9g %0.9g %0.9g" % (st["s"], st["cp"], st["w"])
'4.85438792 44.6579342 383.444594'
>>> st = _Region3(500, 750)
>>> "%0.9g %0.9g %0.9g" % (st["P"], st["h"], st["h"]-st["P"]*1000*st["v"])
'78.3095639 2258.68845 2102.06932'
>>> "%0.9g %0.9g %0.9g" % (st["s"], st["cp"], st["w"])
'4.46971906 6.34165359 760.696041'
Region 4, Table A12
>>> st1 = IAPWS97(T=300, x=0.5)
>>> st2 = IAPWS97(T=500, x=0.5)
>>> st3 = IAPWS97(T=600, x=0.5)
>>> "%0.9g %0.9g %0.9g" % (st1.P.MPa, st2.P.MPa, st3.P.MPa)
'0.00353658941 2.63889776 12.3443146'
Region 4, Table A29
>>> st1 = IAPWS97(P=1e5, x=0.5)
>>> st2 = IAPWS97(P=1e6, x=0.5)
>>> st3 = IAPWS97(P=1e7, x=0.5)
>>> "%0.9g %0.9g %0.9g" % (st1.T, st2.T, st3.T)
'372.755919 453.035632 584.149488'
Other test in paper have been upgraded by new equation, i.e. for region 5
or for ancillary equation, the testing is done in iapws testing layer
References
----------
[1]_ Wagner, W., Cooper, J.R., Dittmann, A., Kijima, J., Kretzschmar,
H.-J., Kruse, A., Mareš, R., Oguchi, K., Sato, H., Stöcker, I.,
Šifner, O., Takaishi, Y., Tanishita, I., Trübenbach, J., Willkommen, T.
The IAPWS Industrial Formulation 1997 for the Thermodynamic Properties
of Water and Steam. J. Eng. Gas Turbines & Power 122 (2000) 150-182.
"""
M = unidades.Dimensionless(M)
Pc = unidades.Pressure(Pc, "MPa")
Tc = unidades.Temperature(Tc)
rhoc = unidades.Density(rhoc)
Tt = unidades.Temperature(Tt)
Tb = unidades.Temperature(Tb)
f_accent = unidades.Dimensionless(f_acent)
momentoDipolar = unidades.DipoleMoment(Dipole, "Debye")
[docs]
def __init__(self, **kwargs):
if "P" in kwargs:
kwargs["P"] /= 1e6
elif "h" in kwargs:
kwargs["h"] /= 1e3
elif "s" in kwargs:
kwargs["s"] /= 1e3
st = IAPWS(**kwargs)
self.status = st.status
self.msg = st.msg
if self.status:
self.calculo(st)
[docs]
def calculo(self, st):
self.x = unidades.Dimensionless(st.x)
self.region = st.region
self.phase = self.getphase(phase=st.phase)
self.name = "iapws97"
self.synonim = "R-718"
self.CAS = "7732-18-5"
self.T = unidades.Temperature(st.T)
self.P = unidades.Pressure(st.P, "MPa")
self.Tr = unidades.Dimensionless(st.Tr)
self.Pr = unidades.Dimensionless(st.Pr)
self.v = unidades.SpecificVolume(st.v)
self.rho = unidades.Density(st.rho)
self._cp0()
self.Liquido = ThermoWater()
self.Gas = ThermoWater()
if self.x == 0:
# only liquid phase
self.fill(self, st.Liquid)
self.fill(self.Liquido, st.Liquid)
self.sigma = unidades.Tension(st.sigma)
self.Hvap = unidades.Enthalpy(None)
self.Svap = unidades.SpecificHeat(None)
elif self.x == 1:
# only vapor phase
self.fill(self, st.Vapor)
self.fill(self.Gas, st.Vapor)
self.Hvap = unidades.Enthalpy(None)
self.Svap = unidades.SpecificHeat(None)
else:
# two phases
self.fill(self.Liquido, st.Liquid)
self.sigma = unidades.Tension(st.sigma)
self.fill(self.Gas, st.Vapor)
self.h = unidades.Enthalpy(st.h)
self.s = unidades.SpecificHeat(st.s)
self.u = unidades.SpecificHeat(st.u)
self.a = unidades.Enthalpy(st.a)
self.g = unidades.Enthalpy(st.g)
self.cv = unidades.SpecificHeat(None)
self.cp = unidades.SpecificHeat(None)
self.cp_cv = unidades.Dimensionless(None)
self.w = unidades.Speed(None)
self.Hvap = unidades.Enthalpy(st.Hvap, "kJkg")
self.Svap = unidades.SpecificHeat(st.Svap, "kJkgK")
[docs]
def _cp0(self):
"Set ideal properties to state"""
self.v0 = unidades.SpecificVolume(None)
self.rho0 = unidades.Density(None)
self.h0 = unidades.Enthalpy(None)
self.u0 = unidades.Enthalpy(None)
self.s0 = unidades.SpecificHeat(None)
self.a0 = unidades.Enthalpy(None)
self.g0 = unidades.Enthalpy(None)
self.cp0 = unidades.SpecificHeat(None)
self.cv0 = unidades.SpecificHeat(None)
self.cp0_cv = unidades.Dimensionless(None)
self.w0 = unidades.Speed(None)
self.gamma0 = self.cp0_cv
self.rhoM0 = unidades.MolarDensity(None)
self.hM0 = unidades.MolarEnthalpy(None)
self.uM0 = unidades.MolarEnthalpy(None)
self.sM0 = unidades.MolarSpecificHeat(None)
self.aM0 = unidades.MolarEnthalpy(None)
self.gM0 = unidades.MolarEnthalpy(None)
self.cpM0 = unidades.MolarSpecificHeat(None)
self.cvM0 = unidades.MolarSpecificHeat(None)
[docs]
def fill(self, fase, st):
"""Fill phase properties"""
fase._bool = True
fase.M = self.M
fase.v = unidades.SpecificVolume(st.v)
fase.rho = unidades.Density(st.rho)
fase.Z = unidades.Dimensionless(st.Z)
fase.h = unidades.Enthalpy(st.h, "kJkg")
fase.s = unidades.SpecificHeat(st.s, "kJkgK")
fase.u = unidades.Enthalpy(st.u, "kJkg")
fase.a = unidades.Enthalpy(st.a, "kJkg")
fase.g = unidades.Enthalpy(st.g, "kJkg")
fase.fi = [unidades.Dimensionless(st.fi)]
fase.f = [unidades.Pressure(st.f, "MPa")]
fase.cv = unidades.SpecificHeat(st.cv, "kJkgK")
fase.cp = unidades.SpecificHeat(st.cp, "kJkgK")
fase.cp_cv = unidades.Dimensionless(st.cp_cv)
fase.gamma = fase.cp_cv
fase.w = unidades.Speed(st.w)
fase.rhoM = unidades.MolarDensity(fase.rho/self.M)
fase.hM = unidades.MolarEnthalpy(fase.h*self.M)
fase.sM = unidades.MolarSpecificHeat(fase.s*self.M)
fase.uM = unidades.MolarEnthalpy(fase.u*self.M)
fase.aM = unidades.MolarEnthalpy(fase.a*self.M)
fase.gM = unidades.MolarEnthalpy(fase.g*self.M)
fase.cvM = unidades.MolarSpecificHeat(fase.cv*self.M)
fase.cpM = unidades.MolarSpecificHeat(fase.cp*self.M)
fase.alfav = unidades.InvTemperature(st.alfav)
fase.kappa = unidades.InvPressure(st.xkappa, "MPa")
fase.kappas = unidades.InvPressure(st.kappas, "MPa")
fase.mu = unidades.Viscosity(st.mu)
fase.nu = unidades.Diffusivity(st.nu)
fase.k = unidades.ThermalConductivity(st.k)
fase.alfa = unidades.Diffusivity(st.alfa)
fase.epsilon = unidades.Dimensionless(st.epsilon)
fase.Prandt = unidades.Dimensionless(st.Prandt)
fase.n = unidades.Dimensionless(st.n)
fase.joule = unidades.TemperaturePressure(st.joule)
fase.deltat = unidades.EnthalpyPressure(st.deltat)
fase.betap = unidades.Density(st.betap)
fase.alfap = unidades.Density(st.alfap)
fase.fraccion = [1]
fase.fraccion_masica = [1]
[docs]
class IAPWS97_PT(IAPWS97):
"""Derivated class for direct P and T input"""
[docs]
def __init__(self, P, T):
IAPWS97.__init__(self, T=T, P=P)
[docs]
class IAPWS97_Ph(IAPWS97):
"""Derivated class for direct P and h input"""
[docs]
def __init__(self, P, h):
IAPWS97.__init__(self, P=P, h=h)
[docs]
class IAPWS97_Ps(IAPWS97):
"""Derivated class for direct P and s input"""
[docs]
def __init__(self, P, s):
IAPWS97.__init__(self, P=P, s=s)
[docs]
class IAPWS97_Px(IAPWS97):
"""Derivated class for direct P and x input"""
[docs]
def __init__(self, P, x):
IAPWS97.__init__(self, P=P, x=x)
[docs]
class IAPWS97_Tx(IAPWS97):
"""Derivated class for direct T and x input"""
[docs]
def __init__(self, T, x):
IAPWS97.__init__(self, T=T, x=x)
if __name__ == "__main__":
import doctest
doctest.testmod()
