Developmental Research of Solar Still

研制了一种多效热扩散太阳能蒸馏器，并对其进行了高效研究。海水被提供给附着在隔板下面的多孔芯，第一级蒸发太阳强度，其他阶段由潜热提供，这发生在下一隔板之上的冷凝。通过实验数据对该模型进行了验证。利用该模型进行的计算表明，天气、设计和操作条件对生产率的影响。在防止结垢的条件下，使生产率最大化的最佳进料速度近似为几何级数。其次，利用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吻合较好。对生产率的变化或参数的阶跃响应近似为一阶系统。盐水投加量分三种类型，分别为日落、后续和日落，并进行了优化。用混凝土板代替金属受热板的可行性得到了证实。这样，盐水原料就可以通过附着在隔板下面的纤维灯芯流过，然后蒸发。但芯子上的干燥和鳞片会让人感到不安。因此，本文对蒸馏塔内的传热传质进行了详细的研究，分析了导流板内的温度分布。结果表明，计算结果较好地反映了整体换热系数的估算和对流换热的影响。最后，本文提出了一种新型太阳能蒸馏器的设计思路，即在斜板后加装带弯头的多孔芯。实验研究了蒸馏器倾角、弯曲侧倾角和进料量对芯内流量的影响。

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.