The cascaded latent heat thermal energy storage (CLH-TES) is a kind of thermal energy storage technology with promising commercial prospects. The heat transfer enhancement of CLH-TES system by adding uneven number/height of fins for different phase change material (PCM) layers (uneven number/height layout) was numerically investigated. Firstly, for the system adding same number/height of fins for all the PCM layers (even number/height layout), the influences of number and height of fins on the charging and discharging performance were compared. Then, the charging and discharging performances of the systems with uneven number/height layout of fins were calculated. The results show, comparing to the even number layout,the system with uneven number layout can shorten the total time for the melting and solidification processes by 5.2% and increase the average charging rate by 12.6%. Besides, comparing to the even height layout, the system with uneven height layout can slightly decrease the total time for the melting and solidification processes but hardly affect the average charging and discharging rate. The findings can guidance the design of heat transfer enhancement to the CLH-TES with fins.
