Abstract
The present study utilizes sulfuric acid (H2SO4) solution and sodium bicarbonate (NaHCO3) solution mixing in the minichannel to produce carbon dioxide (CO2) through chemical reactions to simulate the two-phase flow transportation at the anode side of a DMFC through the following chemical reaction. Research results shows that the upstream flow pattern in three kinds of flow channel (SSF, SDSF-2□, SDSF-3□) is mostly bubbly flow; the downstream flow pattern is mostly slug flow or annular flow. Few CO2 bubbles are generated in SDSF-2□□Under the condition of low concentration. This could be the fluid velocity in SDSF-2□□□is fast, causing poor mixing of two working solutions On the other hand, more CO2 bubbles are produced in SDSF-3□□due to slower fluid velocity, and the mixing of two working solutions is better. More CO2 bubbles are generated at U-bends. This could be when fluid flow through a U-bend, a secondary flow will take place there. The CO2 bubbles are generated in three kinds of flow channel growing approximately linearly. The experimental pressure drop part, the pressure drops in SDSF-3□ is lower than those of SSF and SDSF-2□□ All of the two-phase pressure drop data exhibit a small amplitude, high frequency oscillation of about 45Hz.