Effect of return gas temperature in reciprocating and rotary compressor performance for medium and low temperature applications in commercial buildings

Abstract

Energy efficiency in refrigeration and air conditioning vapor compression systems has been focused on the development of modulation methods allowing variation of compressor energy consumption according to refrigeration requirements, or the use of alternative energies for running those compression systems. However, even when a compressor comes with frequency inverter, improper selection can lead the user to spend more energy during low cooling loads; or force the compressor to work under conditions for which it was not designed. Thus, the present article shows how the determination of the return gas temperature of the compressor can affect its performance and may vary according to the type of application. Therefore, the operation of reciprocating and rotary compressors was simulated and monitored under the same nominal conditions and determined its cooling effect and its compression capacity. The results show that for the same type of compressor, differences in system capacity are approximately constant regardless of the type of refrigerant used in low temperature applications. The compressor capacity for medium and low temperature systems is independent of return gas temperature using R-22.