Transmitted, in any form or by any means, electronic, mechanical, photocopying, Part of this database may be reproduced, stored in a retrieval system, or Of Commerce on behalf of the United States of America. However, NIST makes no warranties to that effect,Īnd NIST shall not be liable for any damage that may result from errors or To verify that the data contained therein have been selected on the basis of (NIST) uses its best efforts to deliver a high quality copy of the Database and The National Institute of Standards and Technology
Viscosity and thermal conductivity are modeled with either fluid-specific correlations, an ECS method, or in some cases the friction theory method.National Institute of Standards and Technology Mixture calculations employ a model that applies mixing rules to the Helmholtz energy of the mixture components it uses a departure function to account for the departure from ideal mixing. It implements three models for the thermodynamic properties of pure fluids: equations of state explicit in Helmholtz energy, the modified Benedict-Webb-Rubin equation of state, and an extended corresponding states (ECS) model. REFPROP is based on the most accurate pure fluid and mixture models currently available. The equations are generally valid over the entire vapor and liquid regions of the fluid, including supercritical states the upper temperature limit is usually near the point of decomposition of the fluid, and the upper pressure (or density) limit is defined by the melting line of the substance. Their high accuracy is obtained through many coefficients in the equations, and thus the calculation speed will be slower than other equations such as the Peng-Robinson cubic equations. These equations are the most accurate equations available worldwide. The program uses equations for the thermodynamic and transport properties to calculate the state points of the fluid or mixture. The REFPROP "database" is actually a program and does not contain any experimental information, aside from the critical and triple points of the pure fluids. REFPROP is a Program, not a Database Containing Measurements. This program, developed by the National Institute of Standards and Technology (NIST), calculates the thermodynamic and transport properties of industrially important fluids and their mixtures. In the thermodynamic module also REFPROP is used by CONVAL ®
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