A study on a milk chiller latent storage system with phase change material encapsulated spherical balls

For dispersed or remotely located families, the collection of raw milk takes place less frequently or transportation to the nearest center is not feasible. It requires chilling of collected milk from udder temperature (∼35 °C) to storage temperature (∼4 °C) and maintaining it throughout thus it demands running chilling at the discrete locations. In this study, a novel design of a milk chiller for coolness storage of 12/24 h based on phase change material is presented. System performance has been demonstrated following the prevailing practice of milk collection and loading/unloading of milk. By switching off the refrigeration after a certain interval, the coolness storage was demonstrated to meet the chilling conditions even during the non-availability of power. The study proposes an integrated portable mobile milk chilling system that can move between solar PV plants and the nearest electric grid during non-sunny days. The proposed milk chiller latent storage system (MC-LSS) contains three major components: a helical coil for refrigerant circulation during charging of the system, spherical capsules for encapsulating phase change materials and interspaced occupied brine solution for storing coolness and circulating throughout PCM-filled capsules. MC-LSS is tested under two cases: FLS-12(first loading of milk chiller and storage for 12 h) and SLS-12 (second loading of milk and storage for 12 h). The temperature history of the Milk chiller latent storage system for the FLS-12 h case is qualitatively analyzed which shows an appreciable reduction in milk temperature around 10–15 °C within the first 20 min and in another ∼40 min of further cooling, milk temperature attains the desired storage temperature (4–5 °C).