降膜蒸发-凝结型闭式循环太阳能蒸馏系统的模拟实验研究

EXPERIMENTAL SIMULATION STUDY ON A CLOSED CIRCULATION SOLAR STILL WITH ENHANCED FALLING FILM EVAPORATION AND CONDENSATION

建立了一套采光面积为 1 0 7m2 、主动回收蒸汽潜热及浓海水余热的降膜蒸发 凝结型闭式循环太阳能蒸馏系统 ,用 4盏卤素灯作为太阳能模拟器 ,对该系统进行了模拟实验研究。实验结果表明 ,由于在本蒸馏系统中采用了强迫降膜蒸发及降膜凝结技术 ,使其中大部分的蒸汽潜热以及浓盐水的显热都得到了重复利用 ,单位采光面积的产水量相对于传统的盘式 (单级 )太阳能蒸馏器提高了 2～ 3倍。

An active regenerative solar still with 1.03 m2 enabling to reuse the latent heat of condensation and sensible heat of brine was constructed and tested indoors, using a solar simulator for irradiation. In this still a considerable fraction of the latent and sensible heat was successfully recycled and utilized for preheating the feedstock and recycling air via a falling film evaporator/condenser. The forced thin layer evaporation and film condensation as an efficient enhanced processes for heat transfer were applied in this system. As a result, the freshwater yield was about two to three times greater than that of a conventional basin-type solar still (single-effect). Finally, the practical measurements under sunlight were carried out and the results were compared with that of the indoor experiments.