Equações de Peng-Robinson para misturas de hidrocarbonetos como fluidos refrigerantes

Abstract

Cooling system are used fluids refrigerants and heat pump for thermal Exchange with the environment to be refrigerated. In industrials and commercial environments the most used are R22 and R134a which have high GWP and ODP. Therefore, meetings such as Kyoto, Montreal, COP-21 and others defined that R22 is prohibited from being marketed and used in the industrial environments. Several articles have been and are being published in the scientific field, comparing efficiency, thermal energy, and energy losses of R22 with refrigerants and blends of some refrigerants. Hydrocarbons have zero GWP and ODP these measure the risk of pollution to the environment, their mixtures have been the object of research and comparison with the conventional ones. Example of Hydrocarbon Mixtures: R1270 (propylene) with R290 (propane), R430A, R431A and others. In this work will be investigated mixed hydrocarbons to be analyzed in a thermodynamic cycle, the steam compression having as fundamental the calculations elaborated by the equations of PengRobinson. The aim is to analyze these equations, to validate the results by comparing them with experimental scientific articles, the goal is to show that theoretical thermodynamic analysis by the Peng-robinson equations approaches the practice. The refrigerants used for the results and convalidation were the hydrocarbons Propylene (R1270) and Isobutane (R600a). To validating the theoretical results of this work, the biggest error was of 12% in relation to the experimental one, considering the figures COP x Molecular fraction Propylene, and in relation to the enthalpies the biggest error was of 6% in relation to the experimental one.