Abstract: Salinity gradient power is a kind of chemical potential energy which exists between sea water and fresh water or water with different salt concentrations. Reverse electrodialysis (RED) is a process that transfers the salinity gradient to energy. Compared with other process, RED shows higher energy density. However, the studies on RED are limited to small membrane stacks. Experiments with a larger setup show that power density decreases significantly. Moreover, there is little research on the energy efficiency analysis of the RED process. In this paper, the energy transfer process of RED was simulated mathematically and the structure of the membrane stack was optimized. The power density and energy efficiency of RED at different structural parameters were also analyzed. Decreasing the thickness of the compartment could enhance both power density and energy efficiency greatly. Increasing flow length could result in higher energy efficiency, but average power density would decrease.

Key words: reverse electrodialysis, membranes, mathematical modeling, renewable energy

摘要： 盐差能是存在于海水和淡水之间或者两种含盐浓度不同的海水之间的化学位差能,是以化学能形态存在的海洋能。反电渗析法是一种利用盐差能发电的方法,相比于其他方法,具有更高的能量密度。但是,目前对反电渗析法盐差电池的研究均限于小尺寸膜堆,放大实验发现功率密度显著降低,对过程的能量效率更少有分析。因此,对反电渗析法海洋盐差能利用过程进行数学模拟,对膜堆进行结构优化,研究在不同的结构参数下反电渗析盐差电池的功率密度和能量效率。结果表明,减小隔板厚度可以很大程度地提高反电渗析过程的功率密度和能量效率,增加RED装置的长度会获得较高的能量效率,但是平均功率密度有所降低。

关键词: 反电渗析, 膜, 数学模拟, 再生能源