seuif97 1.2.0

IAPWS-IF97 high-speed shared library(Windows64/32,Linux64),Python API

Contents

• What is seuif97?

• Installation

• Python API

  • Functions of Water and Steam Properties

    • ??(in1,in2,propertyID)

    • ??2?(in1,in2)

  • Functions for the Thermodynamic Process of Steam Turbine

    • Isentropic Enthalpy Drop

    • Isentropic Efficiency(0~100)

• Examples

• propertyIDs in seuif97

What is seuif97?

The seuif97 package is the Python API of the high-speed IAPWS-IF97 shared library.

SEUIF97 is the high-speed shared library of IAPWS-IF97. It is suitable for computation-intensive calculations，such as heat cycle calculations, simulations of non-stationary processes, real-time process monitoring and optimizations.

Through the high-speed library, the results of the IAPWS-IF97 are accurately produced at about 3x speed-up compared to the repeated squaring method for fast computation of integer powers, 10x speed-up compared to the math.pow() of the C standard library.

For Windows and Linux users, the convenient binary library and APIs are provided

• Windows64/32 dynamic library: libseuif97.dll

• Linux64 shared library: libseuif97.so

• APIs: Python, C/C++, Excel VBA, MATLAB, Java, Fortran, C#, Modelica, Rust, Pascal

You may visit https://github.com/thermalogic/SEUIF97 for more information about the shared library and APIs

Installation

If you have an installation of Python with pip, install it with:

• Windows64/32

  >python -m pip install seuif97

• Linux64

  $sudo -H python3 -m pip install seuif97

Python API

Functions of water and steam properties, thermodynamic process of steam turbine are provided in seuif97 package

Functions of Water and Steam Properties

Using seuif97, you can set the state of steam using various pairs of know properties to get any output properties you wish to know, including in the 30 properties (propertyIDs in seuif97)

The following input pairs are implemented:

(p,t) (p,h) (p,s) (p,v) (p,x)

(t,h) (t,s) (t,v) (t,x)

(h,s)

The two types of functions are provided in the seuif97 package:

• ??(in1,in2,propertyID). e.g, h=pt(p,t,4), the propertyID h is 4)

• ??2?(in1,in2). e.g,h=pt2h(p,t)

??(in1,in2,propertyID)

• the propertyID of the calculated property(int, 0-29), see propertyIDs in seuif97 for details

pt(pressure,    temperature, propertyID)
ph(pressure,    enthalpy,    propertyID)
ps(pressure,    entropy,     propertyID)
pv(pressure,    volume,      propertyID)

th(temperature, enthalpy,    propertyID)
ts(temperature, entropy,     propertyID)
tv(temperature, volume,      propertyID)

hs(enthalpy,    entropy,     propertyID)

px(pressure,    quality,     propertyID)
tx(temperature, quality,     propertyID)

• p (pressure) : MPa ;

• t (temperature) : °C

• v (volume) : m^3/kg

• h (enthalpy) : kJ/kg

• s (entropy) : kJ/(kg·K)

• x (quality) :

??2?(in1,in2)

pt2h(pressure, temperature)
pt2s(pressure, temperature)
pt2v(pressure, temperature)
pt2x(pressure, temperature)

ph2t(pressure, enthalpy)
ph2s(pressure, enthalpy)
ph2v(pressure, enthalpy)
ph2x(pressure, enthalpy)

ps2t(pressure, entropy)
ps2h(pressure, entropy)
ps2v(pressure, entropy)
ps2x(pressure, entropy)

pv2t(pressure, volume)
pv2h(pressure, volume)
pv2s(pressure, volume)
pv2x(pressure, volume)

th2p(temperature, enthalpy)
th2s(temperature, enthalpy)
th2v(temperature, enthalpy)
th2x(temperature, enthalpy)

ts2p(temperature, entropy)
ts2h(temperature, entropy)
ts2v(temperature, entropy)
ts2x(temperature, entropy)

tv2p(temperature,  volume)
tv2h(temperature,  volume)
tv2s(temperature,  volume)
tv2x(temperature,  volume)

hs2p(enthalpy,  entropy)
hs2t(enthalpy,  entropy)
hs2v(enthalpy,  entropy)
hs2x(enthalpy,  entropy)

px2t(pressure, quality)
px2h(pressure, quality)
px2s(pressure, quality)
px2v(pressure, quality)

tx2p(temperature, quality)
tx2h(temperature, quality)
tx2s(temperature, quality)
tx2v(temperature, quality)

Functions for the Thermodynamic Process of Steam Turbine

Isentropic Enthalpy Drop

ishd(pi,ti,po)

• pi：inlet P，MPa；　ti：inlet T，°C

• po：outlet P，MPa；

Isentropic Efficiency(0~100)

ief(pi,ti,po,to)

• pi：inlet P，MPa； 　ti：inlet T，°C

• po：outlet P，MPa；　to：outlet T，°C

Examples

import seuif97

p，t=16.10,535.10

# ??2?(in1,in2)
h=seuif97.pt2h(p,t)
s=seuif97.pt2s(p,t)
v=seuif97.pt2v(p,t)
print("(p,t),h,s,v:",
      "{:>.2f}\t {:>.2f}\t {:>.2f}\t {:>.3f}\t {:>.4f}".format(p, t, h, s, v))

# ??(in1,in2,propertyid)
t = seuif97.ph(p, h, 1)
s = seuif97.ph(p, h, 5)
v = seuif97.ph(p, h, 3)

print("(p,h),t,s,v:",
     "{:>.2f}\t {:>.2f}\t {:>.2f}\t {:>.3f}\t {:>.4f}".format(p, h, t, s, v))

propertyIDs in seuif97

Properties	Unit	symbol	propertyID
Pressure	MPa	p	0
Temperature	°C	t	1
Density	kg/m^3	d	2
Specific Volume	m^3/kg	v	3
Specific enthalpy	kJ/kg	h	4
Specific entropy	kJ/(kg·K)	s	5
Specific exergy	kJ/kg	e	6
Specific internal energy	kJ/kg	u	7
Specific isobaric heat capacity	kJ/(kg·K)	cp	8
Specific isochoric heat capacity	kJ/(kg·K)	cv	9
Speed of sound	m/s	w	10
Isentropic exponent		ks	11
Specific Helmholtz free energy	kJ/kg	f	12
Specific Gibbs free energy	kJ/kg	g	13
Compressibility factor		z	14
Steam quality		x	15
Region		r	16
Isobaric volume expansion coefficient	1/K	ec	17
Isothermal compressibility	1/MPa	kt	18
Partial derivative (dV/dT)p	m3/(kg·K)	dvdt	19
Partial derivative (dV/dP)T	m3/(kg·MPa)	dvdp	20
Partial derivative (dP/dT)v	MPa/K	dpdt	21
Isothermal Joule-Thomson coefficient	kJ/(kg·MPa)	iJTC	22
Joule-Thomson coefficient	K/MPa	JTC	23
Dynamic viscosity	kg/(m·s)	dv	24
Kinematic viscosity	m^2/s	kv	25
Thermal conductivity	W/(m.K)	tc	26
Thermal diffusivity	um^2/s	td	27
Prandtl number		pr	28
Surface tension	mN/m	st	29