lib.iapws97 module

Library with a wrapper class of iapws97 for IAPWS formulation

All the functionality is included in the main class:

  • IAPWS97: Stream definition using IAPWS-IF97 formulation valid for liquid water or steam

Direct access to normally used input parameters

  • IAPWS97_PT: Derivated class for direct P and T input

  • IAPWS97_Ph: Derivated class for direct P and h input

  • IAPWS97_Ps: Derivated class for direct P and s input

  • IAPWS97_Px: Derivated class for direct P and x input

  • IAPWS97_Tx: Derivated class for direct T and x input

API reference

class lib.iapws97.IAPWS97(**kwargs)[source]

Bases: ThermoWater

Class to model a state for liquid water or steam with the IAPWS-IF97

Parameters:
Tfloat

Temperature [K]

Pfloat

Pressure [MPa]

hfloat

Specific enthalpy [kJ/kg]

sfloat

Specific entropy [kJ/kgK]

xfloat

Vapor quality [-]

lfloat, optional

Wavelength of light, for refractive index [nm]

Methods

calculo(st)

Calculate procedure

fill(fase, st)

Fill phase properties
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 [-]

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

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.

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

M = 18.015268
Pc = 22064000.0
Tc = 647.096
rhoc = 322.0
Tt = 273.16
Tb = 373.1243
f_accent = 0.3443
momentoDipolar = 6.18754725310668e-30
__init__(**kwargs)[source]
calculo(st)[source]

Calculate procedure

_cp0()[source]

Set ideal properties to state

fill(fase, st)[source]

Fill phase properties

class lib.iapws97.IAPWS97_PT(P, T)[source]

Bases: IAPWS97

Derivated class for direct P and T input

__init__(P, T)[source]
class lib.iapws97.IAPWS97_Ph(P, h)[source]

Bases: IAPWS97

Derivated class for direct P and h input

__init__(P, h)[source]
class lib.iapws97.IAPWS97_Ps(P, s)[source]

Bases: IAPWS97

Derivated class for direct P and s input

__init__(P, s)[source]
class lib.iapws97.IAPWS97_Px(P, x)[source]

Bases: IAPWS97

Derivated class for direct P and x input

__init__(P, x)[source]
class lib.iapws97.IAPWS97_Tx(T, x)[source]

Bases: IAPWS97

Derivated class for direct T and x input

__init__(T, x)[source]

References

  • [R1-76] IAPWS; Revised Release on the Surface Tension of Ordynary Water Substance. 2014

  • [R2-83] IAPWS; Release on the Values of Temperature, Pressure and Density of Ordynary and Heavy Water Substances at their Respectives Critical Points. 1992

  • [R4-84] IAPWS; Revised Release on Viscosity and Thermal Conductivity of Heavy Water Substance. 2007

  • [R5-85] IAPWS; Release on Surface Tension of Heavy Water Substance. 1994

  • [R6-95] IAPWS; Revised Release on the IAPWS Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use. 2006

  • [R7-97] IAPWS; Revised Release on the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam. 2012

  • [R8-97] IAPWS; Release on the Static Dielectric Constant of Ordinary WaterSubstance for Temperatures from 238 K to 873 K and Pressures up to 1000 MPa. 1997

  • [R9-97] IAPWS; Release on the Refractive Index of Ordinary Water Substance as a Function of Wavelength, Temperature and Pressure. 1997

  • [R10-06] IAPWS; Revised Release on the Equation of State 2006 for H2O Ice Ih. 2009

  • [R11-19] IAPWS; Release on the Ionization Constant of H2O. 2019

  • [R12-08] IAPWS; Release on the IAPWS Formulation 2008 for the Viscosity of Ordinary Water Substance. 2008

  • [R13-08] IAPWS; Release on the IAPWS Formulation 2008 for the Thermodynamic Properties of Seawater. 2008

  • [R14-08] IAPWS; Revised Release on the Pressure along the Melting and Sublimation Curves of Ordinary Water Substance. 2011

  • [R15-11] IAPWS; Release on the IAPWS Formulation 2011 for the Thermal Conductivity of Ordinary Water Substance. 2011

  • [R16-17] IAPWS; Release on the IAPWS Formulation 2017 for the Thermodynamic Properties of Heavy Water. 2017

  • [SR1-86] IAPWS; Revised Supplementary Release on Saturation Properties of Ordinary Water Substance. 1992

  • [SR2-01] IAPWS; Revised Supplementary Release on Backward Equations for Pressure as a Function of Enthalpy and Entropy p(h,s) for Regions 1 and 2 of the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam. 2014

  • [SR3-03] IAPWS; Revised Supplementary Release on Backward Equations for the Functions T(p,h), v(p,h), and T(p,s), v(p,s) for Region 3 of the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam. 2014

  • [SR4-04] IAPWS; Revised Supplementary Release on Backward Equations p(h,s) for Region 3, Equations as a Function of h and s for the Region Boundaries, and an Equation Tsat(h,s) for Region 4 of the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam. 2014

  • [SR5-05] IAPWS; Revised Supplementary Release on Backward Equations for Specific Volume as a Function of Pressure and Temperature v(p,T) for Region 3 of the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam. 2016

  • [SR6-08] IAPWS; Revised Supplementary Release on Properties of Liquid Water at 0.1 MPa. 2011

  • [SR7-09] IAPWS; Supplementary Release on a Computationally Efficient Thermodynamic Formulation for Liquid Water for Oceanographic Use. 2009

  • [G1-90] IAPWS; Electrolytic Conductivity (Specific Conductance) of Liquid and Dense Supercritical Water from 0°C to 800°C and Pressures up to 1000 MPa. 1990

  • [G2-90] IAPWS; Solubility of Sodium Sulfate in Aqueous Mixtures of Sodium Chloride and Sulfuric Acid from Water to Concentrated Solutions, from 250 °C to 350 °C. 1994

  • [G3-00] IAPWS; Revised Guideline on the Critical Locus of Aqueous Solutions of Sodium Chloride. 2012

  • [G4-01] IAPWS; Guideline on the IAPWS Formulation 2001 for the Thermodynamic Properties of Ammonia-Water Mixtures. 2001

  • [G5-01] IAPWS; Guideline on the Use of Fundamental Physical Constants and Basic Constants of Water. 2016

  • [G7-04] IAPWS; Guideline on the Henry’s Constant and Vapor-Liquid Distribution Constant for Gases in H2O and D2O at High Temperatures. 2004

  • [G8-10] IAPWS; Guideline on an Equation of State for Humid Air in Contact with Seawater and Ice, Consistent with the IAPWS Formulation 2008 for the Thermodynamic Properties of Seawater. 2010

  • [G9-12] IAPWS; Guideline on a Low-Temperature Extension of the IAPWS-95 Formulation for Water Vapor. 2012

  • [G10-15] IAPWS; Guideline on the Thermal Conductivity of Seawater. 2015

  • [G11-15] IAPWS; Guideline on a Virial Equation for the Fugacity of H2O in Humid Air. 2015

  • [G12-15] IAPWS; Guideline on Thermodynamic Properties of Supercooled Water. 2015

  • [AN3-07] IAPWS; Thermodynamic Derivatives from IAPWS Formulations. 2014

  • [AN5-13] IAPWS; Industrial Calculation of the Thermodynamic Properties of Seawater. 2016