Simplified Mechanical and Thermal Simulation-based Design of a Cold Storage System using Macro-encapsulated Ice Plates

Ice-based cold storage offers the advantages of easy availability, cost-effectiveness and high cold storage density, therefore has been widely used in various sectors for load-shifting, temperature retention and energy conservation etc. over recent decades. This paper presents a simplified step-wise simulation-based approach for the design of ice-based cold storage units, from ice plates, encapsulation to cold storage unit comprehensively. The novelty lies in the investigation into the thermal performance of ice plates and cold storage unit, and the mechanical strength of ice plate macro-encapsulation, while decoupling the thermal-mechanical performance and simplifying the 2-dimensional simulation of cold storage unit for decent computational cost-effectiveness. The effectiveness of this design approach was demonstrated and verified through a case study under the given conditions. It was found that the ice plate can be fully charged if the thickness was lower than 50 mm, while the plate macro-encapsulation with a wall thickness of 2 mm together with reinforcement with 3 tie-rods and surface strengthening ribs can constrain the deformation within an acceptable range in the case study. An asymmetrical arrangement of ice plates was employed in the cold storage unit design and provided relatively even-distributed phase transition of ice plates along the heat transfer fluid flow direction. The case study achieved an ice-based cold storage unit which can reach a cold energy storage of 503.98 kWh at a high charging flow rate of 43.29 m 3 /h, and a cold energy extraction of 497.98 kWh at a low discharging flow rate of 9.03 m 3 /h, respectively, over the charging and discharging periods of 8 hours. The proposed design approach is also useful to facilitate the design of different thermal energy storage units using macro-encapsulated phase change materials.