Miao Qingxiu, Zhang Yaoling, Cong Shuo, Guo Fei
School of Energy and Power Engineering, Dalian University of Technology, Dalian 116024, China.
Membranes (Basel). 2021 Apr 21;11(5):304. doi: 10.3390/membranes11050304.
Membrane distillation (MD) processes need a relatively mild temperature gradient as the driving force for desalination. In the field, it is reasonable to utilize solar energy as the heat source for the feed, and seawater as the infinite cold source for condensation. Solar-driven MD provides a route for the practical application of seawater desalination at a small scale. In this work, we focus on floating MD modules with a solar heating bag as the power source, and perform proof-of-principle experiments on the MD performance under various conditioning parameters, including feed flow rate, feed temperature, salinity, air gap, and sea waves. The results indicate that floating solar-driven MD modules are feasible in terms of permeate flux and salt rejection ratio, and the upward evaporation MD configuration leads to a better performance in terms of permeate flux. The simulation and experiments also show that the natural sea waves disturb the heating bag and the MD module floating on the surface of seawater, and effectively enhance the feed circulation and transport in the system.
膜蒸馏（MD）过程需要相对温和的温度梯度作为脱盐的驱动力。在实际应用中，利用太阳能作为进料的热源，海水作为冷凝的无限冷源是合理的。太阳能驱动的MD为小规模海水淡化的实际应用提供了一条途径。在这项工作中，我们专注于以太阳能加热袋为电源的浮动MD模块，并在各种条件参数下对MD性能进行原理验证实验，这些参数包括进料流速、进料温度、盐度、气隙和海浪。结果表明，浮动太阳能驱动的MD模块在渗透通量和脱盐率方面是可行的，并且向上蒸发MD配置在渗透通量方面具有更好的性能。模拟和实验还表明，自然海浪会干扰加热袋和漂浮在海水表面的MD模块，并有效地增强系统中的进料循环和传输。
