Pressure drop behavior in the anode flow field of liquid feed direct methanol fuel cells

In this work, we experimentally investigated the two-phase flow pressure drop behavior in the anode flow field of an in-house fabricated direct methanol fuel cell (DMFC). The anode flow field consisted of a single serpentine flow channel with a cross-sectional area of 2.0 × 2.0 mm2 and a total length of 420 mm. The pressure drops between the inlet and the outlet of the flow channel were measured by varying current density. The experimental results show that at low current densities, the pressure drop increased with increasing current density. After reaching a peak at certain current density, however, the pressure drop began to decrease with increasing current density. It has also been shown that the pressure drop always increased with the methanol solution flow rate. However, either lower or higher flow rates deteriorated the cell performance. The experimental results further show that the pressure drop became almost independent of the current density when the methanol solution flow rate became sufficiently high. The study also reveals that both temperature and methanol concentration had significant influence on the cell performance, but their effects on the pressure drop were small.