Experimental performance evaluation of Aqueosus KCl and PEG6000 solutions as eutectic phase-change materials (PCMs) for portable cold storage applications

The Food and Agriculture Organization (FAO) reported a staggering annual waste of 1.3 billion tons of food worldwide. A significant portion of this waste, approximately 42%, can be attributed to vegetables and fruits. This issue arises from challenges in distribution to remote regions and lengthy supply chains, leading to spoilage before consumers are reached. To preserve the freshness of perishable foods, which require cooler temperatures, recent advancements in cold storage technology have centered on employing phase change materials (PCMs) in different configurations within cold storage.

This research aimed to further enhance portable cold storage performance by using smaller packs, allowing for a broader range of configurations of phase change materials (PCMs). The selected PCMs were a eutectic mixture of 10% KCl with water and 10% PEG6000 with water. The PCMs were put inside eight PCMs within HDPE packs with a mass of 200 grams. The packs were placed in six different configurations in a portable cold storage unit measuring 340 mm x 255 mm x 285 mm. The measurements were focused on temperature distribution within the cold storage unit and heat transmission through its walls.

The results show that optimal performance was achieved by placing the PCM packs on the upper side of the portable cold storage unit. This setup optimized temperature homogeneity within storage, making it more suitable for cold storage applications. Additionally, a eutectic PCM comprising a 10% aqueous KCl solution (KCl wt%) demonstrated its effectiveness in maintaining temperatures above 5°C, with a maximum cooling capacity of 307.59 kJ. Conversely, a 10% aqueous PEG6000 solution (PEG6000 wt%) was capable of sustaining temperatures above 10°C, with a maximum cooling capacity of 332.05 kJ.