低压蒸汽横掠水平降膜管束流动阻力实验研究  

Experimental investigation of steam flow resistance across horizontal tube bundle with falling film at low pressure

作　　者：刘华[1] 沈胜强[1] 龚路远[1] 刘瑞[1] 

机构地区：[1]大连理工大学辽宁省海水淡化重点实验室,辽宁大连116024

出　　处：《大连理工大学学报》2013年第6期811-815,共5页Journal of Dalian University of Technology

基　　金：国家自然科学基金资助项目(50976016);高等学校博士学科点专项科研基金资助项目(20110041110032)

摘　　要：采用模拟方法对海水淡化装置中大型水平管降膜蒸发器内的流动过程进行实验研究．管束采用海水淡化装置中广泛应用的正三角形和转角正方形排列，其管间距为1．3倍管外径．实验在饱和温度为50～70℃，喷淋密度为0．02～0．08kg·m^-1·s^-1的条件下进行．分析了管束排列方式、喷淋密度和饱和温度等因素对流动阻力的影响．实验结果表明，流动阻力在正三角形管束下比在转角正方形管束下大得多．引入Re1、Reg、sa／D、str／D等参数来表征各个影响因素并用来拟合有降膜流动时蒸汽横掠管束的压降预测公式．新拟合的公式误差在±15％以内．Experiments are carried out to simulate the flow characteristics in a large horizontal falling film evaporator of desalination plant. The tube bundle arrangements are regular triangle and rotated square, and the relative tube bundle-pitch ratio is 1. 3, a typical value for evaporators used in desalination. Experiments are conducted with saturated temperature ranging from 50℃ to 70 ℃ and spray density ranging from 0. 02 kg · m^-1 · s^-1 to 0. 08 kg · m^-1 · s^-1. The influences of these factors, such as tube arrangement, spray density and saturated temperature on steam flow resistance are analyzed. The experimental results show that the steam flow resistance across regular triangle tube bundle is bigger than that across rotated square tube bundle. Parameters Re1, Reg, sta/D, str/D are employed to fit the prediction formula. Based on the experimental data, a pressure drop correlation for steam flowing across horizontal tube bundle with falling film is proposed with a standard deviation of ±15%.

关 键 词：流动阻力 喷淋密度 降膜流动 水平管管束 

分 类 号：TK125[动力工程及工程热物理—工程热物理]