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 (cmh@seu.edu.cn)

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 |