关键词: 隔网, 压力延迟渗透过程, 多尺度模型, 数值模拟, 优化

Abstract: In this paper, a multi-scale model combining the local transmembrane osmosis model and the mass transfer in flow channels in a full-scale pressure retarded osmosis(PRO) membrane module was set up to determine the performance of PRO in a full-scale operation(i.e., power density and specific energy) by calculating the parameter distributions along feed and draw channels. This work focused on the effects of porosities, heights and numbers of layer of both feed and draw spacers on the performance of PRO. According to the numerical simulations, higher porosities of feed and draw spacer can achieve higher power densities but lower specific energy. Smaller height of feed spacer and larger height of draw spacer result in higher power densities while the specific energy increases as the heights of feed spacer and draw spacer decrease. Multilayer spacers were found to have adverse effects on the performance. Our findings give insight into designing membrane modules. Feed spacers should have relatively small porosity and small height while draw spacers can have relatively larger porosity and large height, and for both feed and draw spacers, monolayer spacers are recommended.

Key words: spacer, pressure retarded osmosis, multi-scale model, numerical simulation, optimization