Title: Mathematical modelling and performance analysis of a novel auto-cascade refrigeration cycle for ultra-low temperature applications

Authors: Ibrahim Karacayli; Lutfiye Altay; Arif Hepbasli

Addresses: Graduate School of Natural and Applied Sciences, Ege University, 35100 Bornova, Izmir, Turkey ' Department of Mechanical Engineering, Faculty of Engineering, Ege University, 35100 Bornova, Izmir, Turkey ' Department of Energy Systems Engineering, Faculty of Engineering, Yasar University, 35100 Bornova, Izmir, Turkey

Abstract: The 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°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°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°C.

Keywords: ultra-low temperature; refrigeration; auto-cascade refrigeration; ACR; exergy analysis; coefficient of performance; COP; second law efficiency.

DOI: 10.1504/IJEX.2023.134611

International Journal of Exergy, 2023 Vol.42 No.2, pp.229 - 245

Received: 06 Jun 2023
Accepted: 24 Aug 2023
Published online: 30 Oct 2023 *

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