Simulação e construção de um protótipo em 3D do equilíbrio líquido-vapor de substâncias puras

Abstract

The use of computational means in teaching, to view the phase diagrams of pure substances is limited to two-dimensional representations, restricting the interpretation of the data to two variables (pressure and temperature or pressure and volume or temperature and volume). This makes it difficult to understand the processes, since, by definition, pressure can be determined as a function of temperature and volume by relating the three variables simultaneously. Thus, the analysis of a 𝑃𝑣𝑇 surface is useful to show the general relationships between the three phases of matter from the study of the properties of the substance in the state of saturation, critical point, among others. In this work, a prototype was built and a simulation of the three dimensional diagram corresponding to the PvT relationship of pure substances was made, improving the visualization and understanding of the processes involved for future application in the disciplines of Thermodynamics I and II. For this, a prototype was sculpted on a plaster cube of 40cm edge with the aid of a hammer and steel blades. The surface was polished, sanded and painted to give finishes like those of the 3D model. For the surface simulation 𝑃𝑣𝑇 several State Equations were analyzed, and the Peng-Robinson Equation was the one that best represented the relationship between the properties of pure water. Microsoft Excel was used as a tool, with the support of two supplements: XSEOS and OCTOPUS, showing itself as a viable alternative for data representation. Both two-dimensional graphics and three-dimensionais surfaces were analyzed and compared with information found in the literature. In addition to the previous one, the analyzes made it possible to study the volumetric behavior of the isotherms, the prototype being an aid to the integral analysis of the expected 𝑃𝑣𝑇 surface. Finally, some proposals were made to incorporate the prototype and simulation routines developed in the teaching methodology of the thermodynamics I and II of the food engineering course at UFT.