Characterization and simulation of an open piston compressor for application on automotive air-conditioning systems operating with R134a, R1234yf and R290
Abstract A semi-empirical characterization and simulation model for automotive air-conditioning open piston compressor is developed. The model is based on fundamental conservation principles and takes into account pressure drop and heat transfer in suction and discharge passages. Fundamental conservation principles equations, as well as volumetric and isentropic efficiencies, pressure drop, heat transfer and property equations are combined to form a system of non-linear algebraic equations. They are worked out so as to identify constants that are sole characteristics of the compressor and should not vary with different operating conditions or refrigerants. A numerical method determines such constants from existing experimental data, thus characterizing the compressor. Experimental data were obtained from tests carried out by Navarro et al. (2013) for an open piston compressor running with fluids R134a, R1234yf and R290. First, the experimental data were employed to determine the characterization parameters of the compressor. Then, the simulation model, with the R134a-based parameters, was applied to simulate the compressor operation with R1234yf and R290. Good agreement was obtained between predicted and experimental values, proving the suitability of the model for the study of new refrigerants.