Abstract
Temperature control is essential for guaranteeing food safety, preserving quality, and enhancing energy efficiency throughout processing. However, conventional thermal systems frequently result in temperature fluctuations and energy losses. Phase change materials (PCM) are progressively being employed to address these issues due to their remarkable energy storage capacity during phase changes, which provides thermal stability. The current research work's objective is to employ phase change materials of oleic/caprylic acid and oleic/caprylic acid-copper oxide nanofluids during the charging and discharging cycles to extend food preservation. Prior to the start of the investigation, the thermal properties of the oleic/caprylic acid phase change materials and the oleic/caprylic acid-copper oxide nanofluids were examined. These properties encompassed their specific heat, enthalpy, viscosity, latent heat, as well as freezing and melting points. The process of charging and discharging was employed to evaluate the experimental study at a flow rate of 1, 2 kg/min in an ambient environment. Oleic/caprylic acid phase change materials and oleic/caprylic acid phase change materials-copper oxide nanofluids maintain their cooling effectiveness under enhanced ambient conditions for duration of five hours, compared to air flow rates of 1 and 2 kg/min. Furthermore, the findings showed that the inclusion of caprylic acid phase change materials-copper oxide nanofluids in the container enabled the food or vegetable item to be preserved for an additional 110 min, resulting in a preservation period enhancement of roughly 120%. As a result, the phase change materials-copper oxide nanofluids can keep food in the container at a stable temperature for extended periods while being transported and storage. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-025-06341-9.