Energy-efficient compact multi-stage solar desalination by heat recovery with siphon mechanism for seawater feeding
Energy-efficient compact multi-stage solar desalination by heat recovery with siphon mechanism for seawater feeding
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DOI：
10.5004/dwt.2022.28625
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发表时间：
2022
影响因子：
1.1
通讯作者：
M. Fujiwara;Shinobu Yamauchi
中科院分区：
文献类型：
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作者：
M. Fujiwara;Shinobu Yamauchi
利用太阳能从海水中生产淡水是解决水资源短缺问题的一个可持续发展的过程。为了提高太阳能的利用效率，回收利用水蒸气释放的冷凝热是一种有效的方法。本文报道了一种采用多级膜装置的太阳能海水淡化装置，该装置将用于蒸发淡化海水的薄膜部分和用于冷凝热回用的淡水收集部分密集堆积在一起。在该装置中，传热和进水量得到了显著改善，提高了长时间运行的性能。低导热系数的聚甲基丙烯酸甲酯片材比高导热系数的金属片材更适合于水蒸气冷凝热的有效回收。虹吸式海水进料，海水由上往下流动，抑制了盐沉积，维持了淡水生产的性能，而具有帽状进料作用的多级装置的海水淡化性能急剧下降。利用该装置，通过对冷凝热的反复回收，以太阳光照射能量为基础的能源效率达到200%以上。淡水成功地从真实的海水和自然阳光中生产出来。
The production of freshwater from seawater using solar energy is a sustainable process for resolv - ing water scarcity problem. For increasing the utilization efficiency of solar energy, the recycle use of the condensation heat released from water vapor is an effective method. This paper reports a solar desalination of seawater using a compact multi-stage membrane apparatus, where the mem brane part for desalinating seawater by evaporation and the freshwater collecting part for reusing the condensation heat were densely piled up. In the apparatus, heat transfer and water feeding were significantly improved to increase the performance of longer time operation. A poly(methyl meth - acrylate) sheet with low thermal conductivity was found to be more suitable than metal sheets with high thermal conductivity for the efficient recycle of the condensation heat from water vapor. The feeding of seawater by siphon mechanism, where seawater was flowed from top to bottom, sup pressed the salt deposition to maintain the performance of the freshwater production, while the desalination performance was drastically deteriorated in the multi-stage apparatuses with cap illary action for seawater feeding. Using the apparatus, the energy efficiency based on the energy from irradiated sunlight reached more than 200% by the repeated recoveries of the condensation heat. Freshwater was successfully produced from actual seawater with natural sunlight.