Experimental performance of an R-22-based refrigeration system for use with R-1270, R-438A, R-404A and R-134a

In this work, the alternative refrigerants were evaluated as a drop-in of an R-22-based refrigeration system. The tested system comprises a variable-speed scroll compressor, an electronic expansion valve, a hot-and-cold water circuit and their respective heat exchangers. To make a fair comparison among fluids, only the lubricant type and refrigerant charge were varied to ensure good system functionality. The system performance was evaluated, varying the expansion valve opening to achieve evaporation temperatures of -5 degrees C, -10 degrees C and -15 degrees C. The same methodology was applied for various frequencies using an inverter drive. It was carried out in more than 200 experiments, and the response surface method was used to analyze the results. For all tested conditions, the R-438A was the most flexible alternative among the tested refrigerants as a drop-in of R-22 operating with a scroll compressor since the system operated in a wider range of values. Meanwhile, the R-1270 had the highest cooling capacity value and the lowest TEWI. (C) 2017 Elsevier Ltd and IIR. All rights reserved.