倾斜降膜蒸发特性实验研究  

Experimental Study on Evaporation Characteristics of Inclined Falling Film

作　　者：倪明江[1] 王菲[1] 肖刚[1] 朱伟军[1] 王锡辉[1] 岑可法[1] 

机构地区：[1]浙江大学热能工程研究所,能源清洁利用国家重点实验室,杭州310027

出　　处：《动力工程学报》2013年第7期544-549,566,共7页Journal of Chinese Society of Power Engineering

基　　金：国家自然科学基金资助项目(50676082)

摘　　要：以电加热作为供热热源来模拟太阳能,研究了不同工况下倾斜降膜蒸发特性,通过对蒸馏器吸热面和冷凝面划分等间距小区段,根据液膜和冷凝面的温度分布,利用Dunkle模型预测了蒸馏器的产水速率.结果表明:热流密度、单位长度给水质量流量、倾斜角度和单位长度冷却水质量流量是影响蒸馏器产水速率的主要因素;产水速率随着热流密度的增大呈线性增加;在单位长度给水质量流量为5.5～10.0kg/(h.m)时,产水速率随着单位长度给水质量流量的减小呈线性增大,单位长度给水质量流量为0.7～5.5kg/(h.m)时,产水速率波动较小;在倾斜角度为15°～60°时,产水速率随着倾斜角度的增大而增大;冷却水均匀地流过冷凝面上表面有助于增大蒸馏器的产水速率;蒸馏器吸热面和冷凝面划分的区段越多,模型预测值与实验值吻合越好.Evaporation characteristics of inclined falling film were studied under various working conditions by adopting electric heat instead of solar energy, while the still＇s distillate production rate predicted using Dunkle model based on temperature distribution of the liquid film and condensing surface by dividing both the heat absorbing and the condensing surface into evenly-spaced segments. Results show that the heat flux density, feed water flow, inclination angle, and cooling water flow are the main factors affecting the distillate production rate, which increases linearly with the rise of heat flux density; when the feed water flow is within 5.5-10.0 kg/（h ·m）, the distillate production rate increases linearly with the decrease of feed water flow, whereas when the feed water flow is within 0.7-5.5 kg/（h·m）, the distillate production rate basically remains unchanged; In the range of inclination angle varying from 15° to 60°, the distillate production rate increases as the inclination angle increases; The still＇s distillate production rate would be improved when the cooling water uniformly flows through upper half of the condensing surface. The more segments the heat-absorbing and the condensing surface are divided into, the better agreement would be between the predicted values and experimental results.

关 键 词：蒸馏器 产水速率 热流密度 给水质量流量 倾斜降膜 Dunkle模型 

分 类 号：TK51[动力工程及工程热物理—热能工程]