液-液直接接触式制取流体冰的液滴形成特性  

Drop Formation in the Direct Contact Heat Transfer of Liquid-liquid System Applied to Dluid Ice Production

作　　者：梁坤峰[1] 高春艳[1] 王林[1] 

机构地区：[1]河南科技大学河南省汽车节能与新能源重点实验室,河南洛阳471003

出　　处：《应用基础与工程科学学报》2012年第2期311-320,共10页Journal of Basic Science and Engineering

基　　金：国家自然科学基金(50906021);河南省科技攻关(102102210162);河南省自然科学研究计划(2009A470002)

摘　　要：分散液体破碎形成液滴过程是液-液直接接触式制取流体冰系统的关键环节.基于图像采集与处理方法实验研究了非相溶冷媒(环境液体)中水(分散液体)喷射形成液滴特性,提出了分散液体破碎形成液滴的两种模式和3类射流破碎形状特征,获得了射流长度脉动和液滴平均粒径基于雷诺数的变化规律以及液滴形成的区域特性,确定了液滴粒径分布的经验分布函数.结果表明,随雷诺数的增加,分散液体破碎总是形成单液滴,其液滴形成模式由滴流发展为层流射流,且射流破碎形状由串珠单液滴向不规则液团转变,并演变为长条形液柱;在层流射流模式下,射流长度的脉动均具有随机和非周期特点,其脉动均值持续增长,液滴平均粒径则先减小后增加,其最小值出现在滴流向层流射流转变时.通过Pearsonχ2拟和优度检验,液滴粒径分布符合Rosin-Rammler分布函数,其显著性水平均达到0.03.Liquid-liquid atomization was the key technique of the direct contact heat transfer of liquid-liquid system for fluid ice production.Characteristic of drop formation on water jetted in another immiscible oil were experimentally studied by means of image gathering and processing.Two types of drop formation forms and three series of breakup shape of dispersive liquid atomization were presented.The change rules of drop formation ranges,jet break-up intensity,jet length fluctuation and drop average diameters related to the Reynolds number were obtained.Empirical distribution function of drop size was also confirmed.The results showed that with increasing Re,single droplet always was formed when dispersive liquid breakup happened in freezing condition,its breakup forms were developed from dripping to the laminar jet,jet breakup shapes of drop formation also were changed from single bead-droplet to irregular liquid agglomerate then to strip liquid column.Under the laminar jet,jet length fluctuation was characterized by random and no periodic,average jet length always decreased and but average drops diameter increased at first and then decreased,its minimum happened at the transition process from dripping to the laminar jet.The method of Pearson χ2 test was applied when a function of Rosin-Rammler drop size distribution was assumed,and it was found that the empirical function could exactly describe drop size distribution with significance level α=0.03 under the whole experiment conditions.

关 键 词：液滴 破碎 射流 拟合优度检验 

分 类 号：TB657.1[一般工业技术—制冷工程]