Performance of Reciprocating Compressors with Non-Azeotropic Mixtures

Performance of a reciprocating refrigerator compressor with mixed-refrigerants (MR) was investigated experimentally. The current, standard methods of testing compressors and presenting performance data were found unsuitable for MR, and a new experimental apparatus was designed for a ·direct flowrate measurement with MR. Representative test data for Refrigerant R-12 and for a mixture of R-22/R-114 were presented . and analysed. It was shown that by excluding the suction-gas heating effect through a direct measurement of refrigerant temperature prior to entering the compression chamber, data for various refrigerants could be correlated in a consistent thermodynamic framework. Results show a direct relationship between the overall, mechanical work of compression and the theoretical work for a reversible, isentropic compression. Furthermore, volumetric flowrates were well-correlated by a ·simple "constant volume re-expansion" model for a wide variety of refrigerants and operating conditions. Finally, a simple model W?~ outlined for predicting flowrate and power consumption for the compressor under inve~tiga­ tion for any refrigerant with either single or multiple components. PERFORMANCE OF RECIPROCATING COMPRESSORS WITH NON-AZEOTROPIC MIXTURES In the recent years there has been a growing interest in the use of mixtures of