|
Saturation pressure |
|
|
Saturation temperature |
|
|
Bubble density |
|
|
Dew density |
|
|
Bubble Enthalpy |
|
|
Dew Enthalpy |
|
|
Bubble Entropy |
|
|
Dew Entropy |
|
As it can be seen, the fitted formulas consist basically of the coefficient ei as well as of the parameters Meani and Stdi. These coefficients are the fitting coefficients and must be obtained during a fitting procedure. While the fitting procedure, the formulas presented above are fitted to external data (e.g. obtained from measurements or external media libraries) and the fitting coefficients are determined.
Assumptions and limitations
The fitting procedure is performed for a predefined range of the external data that is given in terms of, for example, temperature and pressure. As a consequence, the fitting coefficients are also just valid within the predefined range of external data.
References
Thorade, Matthis; Saadat, Ali (2012): HelmholtzMedia - A fluid properties library. In: Proceedings of the 9th International Modelica Conference; September 3-5; 2012; Munich; Germany. Linköping University Electronic Press, S. 63–70.
Sangi, Roozbeh; Jahangiri, Pooyan; Klasing, Freerk; Streblow, Rita; Müller, Dirk (2014): A Medium Model for the Refrigerant Propane for Fast and Accurate Dynamic Simulations. In: The 10th International Modelica Conference. Lund, Sweden, March 10-12, 2014: Linköping University Electronic Press (Linköping Electronic Conference Proceedings), S. 1271–1275