Aplicación de ecuaciones de estado cúbicas y desarrollo de correlaciones numéricas para el cálculo de propiedades termodinámicas en saturación de refrigerantes para su uso en microcontroladores

The state-of-the-art of computer libraries in the field of thermodynamic properties are based on the Helmholtz energy equation. Unfortunately, the use of high-level programming languages and its complex implementation often exceeds the memory limit of most microcontrollers. In this context, after examination of the behavior of five variants of the Peng-Robinson equation, a set of simple equations for the saturation properties of common refrigerants that exceeded the precision of the former ones were developed. The proposed correlations are directly programmable in C language, facilitating the implementation in microcontrollers. Several prototype equations were fitted to the thermodynamic data in the reference RefProp library for a few thermodynamics properties by means of a non-linear multiparametric least-squares fitting procedure. Finally, a discussion of the best function for each property, as well as the average and local coefficients and uncertainties have been reported for several common refrigerants.