Numerical study on heat transfer enhancement of a proton exchange membrane fuel cell with the dimpled cooling channel

As the power density of a proton exchange membrane fuel cell (PEMFC) increases, the problems of internal heat accumulation and non-uniform temperature distribution are becoming significant. In this paper, a novel cooling channel with dimple structures is designed and a three-dimensional PEMFC numerical model is established. When comparing to the conventional channels, the heat transfer performance of dimpled channel is 10% higher than the smooth one, and the pressure loss is almost 13% lower than that of wavy channel. In addition, the optimization of dimple structure parameters is investigated based on the index of uniformity temperature ( IUT ) and performance evaluation criteria ( PEC ) of heat transfer. It is found that a diameter-to-depth ratio of 4 is recommended when the dimple diameter is less than 0.80 mm. Furthermore, the clock-wise vortex observed inside the dimple is considered to be the main reason affecting heat exchange. This study will contribute to the design of cooling channels for high-power density PEMFCs in the future. • A dimpled cooling channel was designed to enhance the heat transfer of PEMFCs. • The heat transfer was improved by 10% on average compared to the smooth channel. • The pressure loss was almost 13% lower than that of the wavy channel. • Heat transfer performance was optimal as diameter-to-depth ratio of dimple was 4.