Energy Reports (Nov 2022)
Numerical analysis of the performance of proton exchange membrane fuel cell with longitudinal vortex generators
Abstract
To improve the performance of proton exchange membrane fuel cell (PEMFC), in this study the combination of longitudinal vortex generators (LVGs) and cathode channel is proposed to improve the power density performance and optimize the water-thermal management of PEMFC with a less pressure loss. The effects of the shape, spacing, angle of attack, and number of LVGs on the performance of PEMFC are investigated via numerical simulation. The results show that the current density of the PEMFC improved the most significantly by installing five groups of rectangular plane winglet with a 12 mm spacing and 45° angle of attack in the cathode channel, and that the peak current density increases by 33.3% with additional flow resistance loss of 164.64% than the initial design. The current density of the PEMFC increases with the increase of spacing, angle of attack, and number of vortex generator groups. Moreover, the vortex generator improves the distribution uniformity of temperature, water content, and oxygen content inside the PEMFC. Importantly, it is also observed that the secondary flow intensity of PEMFC channel is positively correlated with the current density of the PEMFC. When the angle of attack is 45°, the vorticity increases the most, i.e., 16.79% higher than that without a VG. Ultimately, the pressure drop and overall performance indicator of PEMFC with LVGs are demonstrated. Compared with the initial design, except the comprehensive performance of the 0° angle of attack has been improved, that of other schemes has been reduced. It is worth noting that, for other published optimization schemes, the research scheme proposed in this paper has certain advantages in terms of lifting current density with lower resistance loss. Therefore, it is still of great significance to improve the energy density of PEMFC.
