Linking REFPROP with Other Applications
Please note: The information below was developed for Refprop 9.1 (except the VB6 and .NET applications), but in many applications they will still work with Refprop 10. However, in most cases the new material on Github should be used instead of the applications here when linking with Version 10.
4. Mac/Unix/Linux Applications
Github website. The following link will transfer you to the
website that documents all new linking applications for Refprop 10:
https://github.com/usnistgov/REFPROP-wrappers
C Applications. A sample C++ file
comes with the Refprop program and is installed in the Examples directory and
explained in the help file. An example for the C programming
language has been written by Ian Bell. The
zip file is included below:
C.ZIP
VB6
and .NET Applications. The following simple application can
be used to link Refprop 10 with VB6 (these will not work with Refprop 9.1):
SAMPLE.BAS
Ian Spanswick provided the following example for
linking with VB.NET. It is based on the
VBA code in the Refprop.xls Excel file distributed with Version 10.
Refprop_.NET_example.vb
Mac/Unix/Linux Applications. Links to
Refprop on Mac, Unix, or Linux operating systems is being developed by Jorrit
Wronski, Jean-Baptiste Carre, and Nathan Kamphuis.
The application is described at:
https://github.com/jowr/librefprop.so
CAPE-OPEN Applications.
The following weblink gives the details of a third-party application for
linking Refprop to CAPE-OPEN applications.
http://www.amsterchem.com/refpropco.html
Perl
Applications. The following example file for the Perl
programming language has been written by Chermac Rolle, and he has given us permission to distribute
his code to others.
PERL.ZIP
MATLAB Applications. Keith Wait from GE Home
Business Solutions has made the following MATLAB application available.
This application calls the Refprop DLL directly rather than through the mex file provided in previous versions of Refprop.
This release now includes the molar mass, compressibility factor, gross and net
heating values, critical point properties, volumetric expansivity, and a number
of other properties. The routines can now read mixture files
(*.mix). When using these new files, be sure to delete the old
refpropm.mexw32 or refpropm.mexw64 files if you downloaded them previously.
refpropm.m
(uploaded Oct. 17, 2013)
rp_proto.m
rp_proto64.m
Note:
These file names are now lowercase, if you downloaded uppercase versions,
delete them before downloading otherwise the case will be changed and the
files will not work.
If
an error message such as "...is not a valid Win32 application"
occurs, try downloading the file again, most likely the file was corrupted
during the first attempt
For 64-bit MATLAB, the following files should be placed in your Refprop
directory:
REFPRP64_thunk_pcwin64.dll
REFPRP64.DLL
Excel
Applications. The Refprop.xls file that comes with the
program has Visual Basic (VB) code embedded within it to make the connection
between the workbook and the Refprop DLL. However, when working with
anything other than temporary calculations, it is best to start with a blank
workbook that does not have the VB code. In this manner, future updates
to the Refprop program can be made available to all of your old workbooks
through the instructions below.
If calculations do not appear to work and you are located outside of the U.S.,
try switching the period and comma, or the comma and semicolon, to enter the
numbers in the format required by your version of Microsoft products. For example, try both of these to see which
format is required:
=Density("argon","TP","SI",325.5,8.4)
=Density("argon";"TP";"SI";325,5;8,4)
To make the Excel routines in Refprop available to any worksheet in 9.0 (in
version 9.1, this is done automatically for you during the installation), two
environment variables called RPprefix and Path should
be added (you will need administrative rights in order to do this) in a similar
manner as shown below in the User variables section:
Do not add these to your System variables section (and more importantly, do NOT
damage your path statement in the System variables section!). In XP, the
environment variables can be set under Start/Settings/Control
Panel/System/Advanced/Environment Variables, under the "User
variables" option. In Windows 7, this can be found in Start/Control
Panel/System And Security/System/Change settings/Advanced/Environment
variables.
In 64-bit versions of Windows, Microsoft added another Program Files directory
called "Program Files (x86)", which is the default directory where
Refprop gets installed. For the connections to work, you need to either
point to this directory in your path statement or copy all the Refprop files to
the old "Program Files" directory.
The following outlines the procedure for using REFPROP within any spreadsheet
in Office 2007 or 2010:
1. Open REFPROP.xls and save it as an add-in, REFPROP.xla or
REFPROP.xlam, in the main REFPROP folder, C:\Program Files\REFPROP.
2. Go to File/Options/Trust Center/Trust Center Settings (button at
bottom right).
3. Select "Trusted Locations" on the left. Click
"Add new location". Browse to C:\Program Files\REFPROP, select
"Subfolders of this location are also trusted", and click
"OK".
4. Go to File/Options/Add-Ins and select "Excel Add-ins" in the
Manage drop-down box at the bottom, and click Go.
5. Click "Browse", and navigate to C:\Program Files\REFPROP,
select REFPROP.xlam and click OK. IMPORTANT: Do not simply select
REFPROP.xlam when it first comes up, as this will be in the wrong folder
(C:\Documents and Settings\Username\Application Data\Microsoft\AddIns), which
is not trusted and will not work.
6. Select the Data tab, and click on Edit Links. Select
REFPROP.xlam. Click on Change Source and navigate to C:\Program
Files\REFPROP. Select REFPROP.xlam there and click OK. (This is
just to make sure you are connected to the correct Add-in.) If the Data
tab is greyed out, start typing in a Refprop command [such as
“=Density("water","TP","SI",300,1) ] and the
button should become active.
7. Once you have the xla or xlam file set up, you can open a brand new
work book and the functions should be available to you. Do not continue
working with the Refprop.xls file since it still contains the VB code that is
also in the xlam file. In this manner, future updates from NIST of the
Refprop.xls file can be resaved as the xlam file, and all of your work books
will have access to the most recent code.
Other tips:
1. In some cases the macros may not work. Try saving the file as a
macro-enabled workbook (under Save As…).
2. The xls file distributed with version 9.0 sometimes will give false
answers depending on the sequence of calculations if multiple xls files are
open. Switching between the open files may cause the initial setup to be
lost. The updated xls file given above fixes this.
3. For inputs that do not required a 5th parameter, Excel may
require the comma at the end, for example:
=Pressure("water", "TVAP", "SI", 298,)
4. If Excel cannot find the Refprop fluid files, you can copy the
*.FLD and HMX.BNC files into a default directory:
C:\REFPROP\FLUIDS. When the program fails to find the fluid files, it
will look to see if a C:\REFPROP\FLUIDS (or D:) is available, and if so it will
use the files from that source.
5. If you see dual entries for each function in your workbook, then you
have either saved two xla files, or you are working with a file that still
contains the VB code. Start with a blank workbook to eliminate the dual
entries for the latter case.
There have been a number of users who have had problems with the Excel link to
Refprop. In some of these cases and in other situations we have found
that the refprop.dll file had also been installed in either the c:\windows
directory or the c:\windows\system32 directory. If you experience
problems, please do a full hard drive search for refprop.dll and delete all
occurrences except the one in your c:\program files\refprop directory.
Last modified: February 4, 2019