Title: Optimising processes for exergo-sustainability to enhance system efficiency in low-temperature applications

Authors: Olarewaju T. Oginni; Bukola O. Bolaji; Adedotun O. Adetunla; Tien-Chien Jen

Addresses: Department of Mechanical Engineering, Bamidele University of Education, Science and Technology Ikere, Nigeria ' Department of Mechanical Engineering, Federal University Oye, Oye-Ekiti, 23401, Nigeria ' Department of Mechanical Engineering Science, University of Johannesburg, Johannesburg, 2006, South Africa ' Department of Mechanical Engineering Science, University of Johannesburg, Johannesburg, 2006, South Africa

Abstract: This study evaluates the exergo-sustainability of a vapour compression refrigeration system, proposing a process optimisation model for efficient low-temperature use. Using R410A and R404A refrigerants, the system achieved –35°C for 110 minutes, preserving plasma integrity for 72 hours during a power outage. Key performance metrics, including coefficient of performance (COP), exergy efficiency, and sustainability index, were analysed across low and high temperature cycles. Results showed a COP of 2.0, exergy efficiency of 97%, and cooling capacity of 170.7 kJ/kg. This system reduces energy losses and supports portable freezers for preserving heat-sensitive medicines in energy-deficient regions, helping save lives in hot climates.

Keywords: ambient temperature; boiling point; entropy; exergy loss; process optimisation.

DOI: 10.1504/IJEX.2025.149603

International Journal of Exergy, 2025 Vol.48 No.2, pp.101 - 112

Received: 12 Sep 2024
Accepted: 09 Nov 2024
Published online: 07 Nov 2025 *

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