SEUIF97

Purpose: Provide a high-speed shared library for developers to calculate the properties of water and steam in extensive process simulations, such as Computational Fluid Dynamics (CFD), heat cycle calculations, simulations of non-stationary processes, and real-time process optimizations, where the direct IAPWS-IF97 implementation may be unsuitable because of their computing time consumption.

Through the high-speed library, the results of the IAPWS-IF97 are accurately produced at above 3 times computational speed.

    Algorithm of the High-speed IAPWS-IF97 Library: 

      王培红,贾俊颖,程懋华. 水和水蒸汽热力性质IAPWS-IF97公式的通用计算模型[J]. 动力工程,2001,21(6)：1564-1567

      芮嘉敏,孙振业,程懋华. 基于最短加法链状态空间树的IAPWS-IF97快速计算方法[J]. 汽轮机技术,2017,59(4):245-247 

This library is written in ANSI C for faster, smaller binaries and better compatibility for accessing the DLL/SO from different C++ compilers.

For Windows and Linux users, convenient binary packages are provided.

     IF97 shared library: Windows(32/64):libseuif97.dll, Linux(64):libseuif97.so

The package includes bindings for Python, Microsoft Excel.

    Python API：seuif97.py
    
    Microsoft Excel Macro: DEMO_SEUIF97.xlsm,SEUIF97.xlam

Author: Cheng Maohua, Southeast University, Nanjing，China ([email protected])

API

Windows and Linux

• Python API: seuif97.py

• C API: seuif97.h

Using shared library

Windows32/64

1. copy libseuif97.dll to a default path of Windows dll

    C:\Windows\system
   

2. copy seuif97.py to a default path of Python lib

    C:\Python35\Lib 
   

Linux64

1. copy libseuif97.so to a default path of Linux shared lib

   $ sudo cp libseuif97.so /usr/lib/
   

2. copy seuif97.py to a default path of Python lib

   $ sudo cp seuif97.py /usr/lib/python3.5/
   

Demo Python

import seuif97

p=16.10
t=535.10

h=seuif97.pt2h(p,t)

T-s Diagram:

• Diagram_T-S.py

Demo with GCC

• demo.c

#include <stdio.h>
#include <stdlib.h>

#include "seuif97.h"

int main(void) {

    double p=16.13;
    double t=535;
    double h;

    h=seupt(p,t,4);
    printf("(p,t) (%f,%f) h= %f",p,t,h);
    return EXIT_SUCCESS;
}

ExcelVBA32/64

• Excel Add-in Macro:SEUIF97.xlam

• Excel VBA: DEMO_SEUIF97.xlsm

• Guide: SEUIF97_Add-in.doc(Chinese)

SEUIF97 shared library

Functions

   seupt( pressure,    temperature, propertyID)
   seuph( pressure,    enthalpy,    propertyID)
   seups( pressure,    entropy,     propertyID)
   seuhs( enthalpy,    entropy,     propertyID)
   seupx( pressure,    quality,     propertyID)
   seutx( temperature, quality,     propertyID)

• propertyID - int, 0-29,(see Properties in libseuif97)

Function for process

• 1 Isentropic Enthalpy Drop： ishd( pi,ti,pe)

   pi - double,inlet P; ti - double,inlet T
  
   pe - double,outlet P
  

• 2 Isentropic Efficiency： ief( pi,ti,pe,te)

     pi  -double，inlet P; ti  - double,inlet T
  
     pe  -double，outlet P; te  - double, outlet T
  

Properties in libseuif97

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