Additive manufacturing of a topology-optimised multi-tube energy storage device: Experimental tests and numerical analysis

Latent heat thermal energy storage (LHTES) systems with phase change materials (PCMs) are commonly used for storing thermal energy due to their high energy storage density and isothermal nature of the process. However, their performance is limited by PCMs low thermal conductivity. To enhance the heat transfer properties, in this study we investigate the performance of a shell-and-tube energy storage device with topology optimised fins. Selective laser melting (SLM) additive manufacturing technology is proposed to fabricate the topology optimised energy storage device for the solidification process. A series of experiments considering different PCMs and heat transfer fluid (HTF) inlet temperatures are conducted. The thermal performance is assessed and compared with that of a conventional square fin design through numerical simulations of phase changes by computational fluid dynamics (CFD). The results show that the complete solidification time is significantly shortened by using the topology optimised fins. This work demonstrates that the combination of topology optimisation method and additive manufacturing technology offers a promising way to improve the heat transfer performances of LHTES systems.