Ibrahim KaracayliLutfiye AltayArif HepbasliKaracayli, IbrahimHepbasli, ArifAltay, Lutfiye2025-10-0620231742-82971742-830010.1504/IJEX.2023.1346112-s2.0-85179127037http://dx.doi.org/10.1504/IJEX.2023.134611https://gcris.yasar.edu.tr/handle/123456789/7396https://doi.org/10.1504/IJEX.2023.134611The main objective of this study is to assess both energetically and exergetically the performance of a novel auto-cascade refrigeration (NACR) cycle enhanced by an internal heat exchanger using R290/R170. In contrast to the ACR cycle with a -60 degrees C evaporation temperature the NACR cycle displays a COP increase of 140.78% and a 148.67% improvement in exergy efficiency. Additionally there is a notable decrease of 13.77% in compressor discharge temperature. For an evaporation temperature of -55 degrees C the NACR cycle achieves a COP of 0.403 and an exergy efficiency of 14.61% with the compressor discharge temperature registering at 126.60 degrees C.Englishinfo:eu-repo/semantics/closedAccessultra-low temperature, refrigeration, auto-cascade refrigeration, ACR, exergy analysis, coefficient of performance, COP, second law efficiencyEXERGYCoefficient of PerformanceACRRefrigerationCOPSecond Law EfficiencyExergy AnalysisUltra-Low TemperatureAuto-Cascade RefrigerationArticle