Developmental Research of Solar Still

本文介绍了一种多效热扩散式太阳能蒸馏器的研制。海水被供应到附在隔板下面的多孔芯中，并且在第一阶段蒸发太阳强度，在其他阶段蒸发潜热，其发生在相邻隔板上的冷凝。通过实验数据验证了模型的正确性。用该模型进行了计算，揭示了气象条件、设计条件和操作条件对生产率的影响。在不结垢的情况下，使生产率最大的最佳进料速率近似为等比级数。其次，通过建立的仿真模型，研究了该太阳能蒸馏器在非稳态下的动态特性。计算结果与实验室和现场试验数据相吻合。对生产率参数变化的阶跃响应近似为一个三阶系统。卤水投加量在日落、后降和日落三种类型下变化，并进行了优化。证明了用混凝土板代替金属受热板的可行性，从而使盐水进料流过隔板下方的纤维芯并蒸发。但灯芯干燥和结垢的问题发生了。因此，本文详细地研究了板内温度沿流动方向分布的情况下，釜内的传热传质过程。最后，对多孔芯安装在带有弯曲的斜板后的太阳能蒸馏器进行了实验研究。实验研究了蒸馏器倾斜度、侧弯角和进料量对毛细芯内流量的影响。

A multieffect thermal diffusion solar still has been developed and researched fro high efficency. Sea water is supplied into the porous wick attached below partitions and evaporatedly solar intensity at the first stage and by latent heat at the other stages, which is occured on condensating above next partitions.Firstly, this still is simulated by formulating the heat and mass balance equations at the steady state. So the model is verified by experimental data. Calculation with the model showed the effects of weather, design and operation conditions onproductivity. The optimum feed rate in order to maximize the productivity on condition to prevent scaling is approximated to the geometrical series.Secondly Dynamic characteristics of this solar still are researched by the simulation model at the unsteady state. The calculated data agree whth the experimental data in a laboratory and a field test plant. The step response to the change or parameters for the prodcutivity is approximated a tirst order system. Brine feed rate is varied with three types among suntise, subsequent and sunset, and is optimized. Availability of using concrete slab instead of a metalheat receiving plate is substantiated.Thiedly, brine feed is allowed to flow through the fibrous wick attached below partitionsand is evaporated. But probrems of drying and scaling at the wick take palse. So heat and mass transfer in the still is in detail studied in condition of temperature distribution in the plate in dierection of flow. The results showed that estimation on over-all heat transfer coefficient and the effect of heat convection is clarified.Lastly, a new idea is tested for a solar still with the porous wick attached behind an inclined plate habing a bend. The effects of inclination of the still, the side angle of bending and feed rate on flow rate in the wick is experimentally studied.