About

IF97 is a python package used to calculate ordinary/pure water properties based on IAPWs-IF97 formulation. Using this package we can calculate water properties faster and efficient than using steam tables. This package has been verified with values from journals/books in references. In folder GUI, there is simple calculator as an example of implementation of this package as backend/engine/library.

What is IAPWS-IF97?

IAPWS-IF97 is formulation to calculate thermodynamical properties of ordinary/pure water for industrial use (primarily in the steam power industry). It approximate IAPWS-95 (formulation for general and scientific use) but with faster computational speed. The formulation is valid from 273.15 K to 1073.15 K at pressure up to 100 MPa and from 1073.15 K to 2273.15 K at pressure up to 50 MPa. For further details see references

Requirements

1. Python >= 3.10
2. scipy
3. numpy

Examples

Calculate properties at mixed phase using temperature(t) and quality(x) as inputs:

From IF97 import if97


ans = if97(t=273.15, x=0.)
print(ans)

Output

{'psat': 0.6112126774443449, 'tsat': 273.15, 'v': 0.0010002069773244189, 'u': -0.04219916517226274, 's': -0.00015454959194117582, 'h': -0.04158782598765377, 'cp': 4.219933568165597, 'cv': 4.217446063578165}

Calculate properties at mixed phase using presssure(p) and quality(x) as inputs:

From IF97 import if97


ans = if97(p=101.325, x=0.)
print(ans)

Output

{'psat': 101.325, 'tsat': 373.12430000048056, 'v': 0.0010434353664161007, 'u': 418.8849917156877, 's': 1.3067239783648374, 'h': 418.99071780418984, 'cp': 4.216612690426814, 'cv': 3.7678305778810395}

Calculate properties at single phase using pressure(p) and temperature(t) as inputs:

From IF97 import if97


ans = if97(p=101.325, t=373.1243)
print(ans)

Output

{'v': 0.0010434353664157238, 'u': 418.88499171366203, 'h': 418.9907178021641, 's': 1.306723978359408, 'cv': 3.7678305778834753, 'cp': 4.216612690426204}

Note: All units of inputs and outputs are in SI unit, for further details see documentation in each modules.

References

1. IAPWS, R7-97(2012), Revised Release on the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam (The revision only relates to the extension of region 5 to 50 MPa) (August 2007), Available from http://www.iapws.org

2. IAPWS, SR5-05(2016), 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 (June 2014), Available from http://www.iapws.org

3. Kretzschmar, Hans-Joachim, Wagner, Wolfgang. (2019). International Steam Tables Properties of Water and Steam based on the Industrial Formulation IAPWS-IF97 (3rd Edition) Tables, Algorithms, and Diagrams. Berlin: Springer Vieweg.

4. IAPWS, R12-08, Release on the IAPWS Formulation 2008 for the Viscosity of Ordinary Water Substance (September 2008), Available from http://www.iapws.org