REFPROP Documentation - NIST

1 REFPROP DocumentationRelease W. Lemmon, Ian H. Bell, Marcia L. Huber, Mark O. McLindenJun 04, 2018 CONTENTS1 REFPROP Graphical User Information .. Commands ..262 REFPROP DLL API .. API ..55iiiREFPROP Documentation , Release is an acronym for REFerence fluid PROP erties. This program, developed by the National Institute ofStandards and Technology (NIST), calculates the thermodynamic and transport properties of industrially importantfluids and their mixtures. These properties can be displayed inTablesandPlotsthrough the graphical user interface;they are also accessible through spreadsheets or user-written applications accessing theREFPROP is based on the most accurate pure fluid and mixture models currently available.

2 It implements threemodels for the thermodynamic properties of pure fluids: equations of state explicit in Helmholtz energy, the modifiedBenedict-Webb-Rubin equation of state, and an extended corresponding states (ECS) model. Mixture calculationsemploy a model that applies mixing rules to the Helmholtz energy of the mixture components; it uses a departurefunction to account for the departure from ideal mixing. viscosity and thermal conductivity are modeled with eitherfluid-specific correlations, an ECS method, or in some cases the friction theory Documentation , Release GRAPHICAL USER General About REFPROPREFPROP is an acronym for REFerence fluid PROP erties.

3 This program, developed by the National Institute ofStandards and Technology (NIST), calculates the thermodynamic and transport properties of industrially importantfluids and their mixtures. These properties can be displayed inTablesandPlotsthrough the graphical user interface;they are also accessible through spreadsheets or user-written applications accessing theREFPROP is based on the most accurate pure fluid and mixture models currently available. It implements threemodels for the thermodynamic properties of pure fluids: equations of state explicit in Helmholtz energy, the modifiedBenedict-Webb-Rubin equation of state, and an extended corresponding states (ECS) model.

4 Mixture calculationsemploy a model that applies mixing rules to the Helmholtz energy of the mixture components; it uses a departurefunction to account for the departure from ideal mixing. viscosity and thermal conductivity are modeled with eitherfluid-specific correlations, an ECS method, or in some cases the friction theory property formulations and fluid data files were programmed by:Eric W. Lemmon, Ian H. Bell, Marcia L. Huber, and Mark O. McLindenApplied Chemicals and Materials DivisionNational Institute of Standards and TechnologyBoulder, CO is the culmination of several years of revisions and updates.

5 Work never stops on the developmentof thermophysical properties and equations, but the last two years have been especially intense and fully dedicatedto this release. Although there are only four authors of this work, we are very grateful to the many contributions ofour NIST colleagues, including Gary Hardin, Allan Harvey, Chris Muzny, Vladimir Diky, Ala Bazyleva, and JanielReed who have provided support over the last several versions of REFPROP . Also of NIST are Adam Morey, CindyMcKneely, and Sherena Johnson who distribute the product for us to industry.

6 A number of individuals from industryhave contributed continuously over the last several years; we are indebted to them for their help, and we thank TobiasLoew, Nik Felbab, Nicolas James, Dan Williams, Jim Pollard, and Stuart acknowledge our many colleagues whose property models we have taken from the literature, and without whichthis database would be much reduced in scope. In particular, the Ruhr University in Bochum, Germany, has for3 REFPROP Documentation , Release decades worked alongside us in the development of equations of state.

7 The contributions of Wolfgang Wagner,Roland Span, and Monika Thol can easily be seen by browsing through the fluid information. We thank Marc Assaelof Aristotle University of Thessaloniki (Greece) for his many contributions to the development of transport propertyformulations, and Ryo Akasaka of Kyushu Sangyo University for his contributions to the refrigerant equations ofstate. We also thank our colleagues within our division whose efforts have made possible the NIST/TRC SOURCEand TDE Databases, of which we have made extensive use for our data needs required to develop thermophysicalproperty REFPROP is a program built on equations of state, its entire existence is built on a foundation of experi-mental data, some of which dates back to the late 1800s.

8 Through experimental measurements, especially the highlyaccurate values of Wolfgang Wagner, Reiner Kleinrahm, Martin Trusler, Mark McLinden, Markus Richter, their stu-dents and colleagues, and many others, equations are built that are then used throughout industry world-wide. Manythings that touch our lives have been influenced in one way or another by these measurements. Power generation aloneaffects all, and the properties from these equations influence the efficiency and design of that infrastructure. Likewise,heating, cooling, and transportation have all been influenced by the measurements and subsequent property are greatly indebted to the enormous work of so many scientists and engineers that continues unseen by development of this software package was supported by the NIST Applied Chemicals and Materials Division andthe NIST Standard Reference Data Program.

9 The development of the models and the measurement of the data onwhich REFPROP is based have been supported over a period of many years by numerous :Please visit the REFPROP FAQ web site as your first resource when you encounter difficulties orhave questions. Most email enquiries are answered by pointing to the FAQ. Using the FAQ will save valuable NIST resources that can be used to further develop REFPROP .*Certain trade names and other commercial designations are used in this work for the purpose of clarity.

10 In no casedoes such identification imply endorsement by the National Institute of Standards and Technology, nor does it implythat the products or services so identified are necessarily the best available for the CautionsUsers of the REFPROP program should be aware of several potential pitfalls:If you experience large differences in your expected values of enthalpy or entropy as compared to those calculated bythe program, see information onReference the units in the Options/Units menu does not change the units on the tables already created, but only for newtables and equation parameters for mixtures composed of natural gas fluids come from the 2008 GERG model (seePref-erencesfor the reference).