CAJ | 학술논문

在直接甲醇燃料电池(DMFC)中,阳极催化层表面反应生成的CO_2气体通过扩散层,及时排出阳极通道,对提高DMFC电流密度具有重要意义,因此研究气泡脱离孔口的过程很有益.今采用Fluent 6.2.16对CO_2气泡脱离扩散层孔口过程、两孔时气泡形成及聚并过程进行了数值模拟,考察了阳极通道内液体流速、扩散层孔道直径等因素对气泡脱离的影响.结果表明,阳极通道内液体流速越大,气泡脱离扩散层孔口所需的时间越短;扩散层孔道直径越大,气泡脱离扩散层孔口所需的时间越长,且生成的气泡越大;由于从相邻两扩散层孔道出来的气泡的阻挡和挤压作用,使得两气泡周围的压力分布与单气泡不同,气泡脱离过程与从单个扩散层孔口的脱离过程有所不同,脱离时间更早.
재직접갑순연료전지(DMFC)중,양겁최화층표면반응생성적CO_2기체통과확산층,급시배출양겁통도,대제고DMFC전류밀도구유중요의의,인차연구기포탈리공구적과정흔유익.금채용Fluent 6.2.16대CO_2기포탈리확산층공구과정、량공시기포형성급취병과정진행료수치모의,고찰료양겁통도내액체류속、확산층공도직경등인소대기포탈리적영향.결과표명,양겁통도내액체류속월대,기포탈리확산층공구소수적시간월단;확산층공도직경월대,기포탈리확산층공구소수적시간월장,차생성적기포월대;유우종상린량확산층공도출래적기포적조당화제압작용,사득량기포주위적압력분포여단기포불동,기포탈리과정여종단개확산층공구적탈리과정유소불동,탈리시간경조.
In the direct methanol fuel cell (DMFC), CO_2 gas is generated on the surface of the anode catalyst layer, it should pass through the orifices on the diffusion layer and flow into the anode channel, via which the CO_2 is exhausted from the DMFC. Exhaust promptly the CO_2 from the DMFC is important for the improvement of the current density of the DMFC, therefore knowing the CO_2 detachment process from the diffusion layer orifice is helpful. Fluent 6.2.16 was used to simulate the detachment process of the CO_2 bubble from the orifice of the diffusion layer, and the processes of bubble formation and coalescence when bubbles flow out from adjacent diffusion layer orifices were simulated too. The effects of the liquid velocity in anode channel and the size of the diffusion layer orifice on the bubble detachment were investigated, and the results show that the faster the liquid velocity in the anode channel, the shorter the time for bubble detaching from the diffusion layer orifice. The larger the size of diffusion layer orifice, the longer the time for bubble detaching from it, and the larger the bubble forming in the anode channel. Due to the obstruction and compression between the bubbles formed from two adjacent diffusion layer orifices, in the anode channel, the pressure distribution near two adjacent bubbles is different from that around the single bubble formed when only one diffusion layer orifice exists; the bubble detachment process for bubbles formed from two adjacent orifices is different from that for one bubble formed from single diffusion layer orifice, and the bubbles detach earlier than the bubble formed from single diffusion layer orifice.