摘要
为建立适用于盐水喷雾蒸发数值模拟的单液滴蒸发模型,开展了NaCl溶液的单液滴蒸发析晶研究。首先,搭建了可同时测量液滴质量、温度、粒径的单液滴蒸发可视化实验平台,基于液滴的流致振动特性,提出了利用低通滤波改善振动信号对质量测量影响的方法;其次,开展了初始质量分数为10%的NaCl溶液液滴蒸发实验,明确了盐分析出对液滴温度、粒径和蒸发率的影响规律;最后,基于实验数据,获得了相对活化能和无量纲粒径随液滴干基含水率的变化关系,并建立了NaCl溶液液滴的反应工程法模型。数值模拟结果表明:所提模型预测结果的最大相对误差小于8%。该实验平台可为含析出性溶质液滴干燥过程中的质量测量提供重要借鉴,所提出的反应工程法模型也可用于NaCl溶液喷雾干燥的大规模高效数值计算。
To establish a droplet evaporation model for the numerical simulation of brine spray evaporation,the evaporation and crystallization processes of brine droplets were investigated.Firstly,a single droplet evaporation visualization experimental platform was built to simultaneously measure the variations in droplet mass,temperature,particle size and morphology during the evaporation.Based on the flow-induced vibration characteristics of the droplet suspension device,the low-pass filtering method was proposed to eliminate the influence of vibration signals on mass measurement.Secondly,the evaporation experiment using 10%NaCl droplet was carried out to investigate the influence of the salt crystallization process on the droplet temperature,particle size and evaporation rate.Finally,based on the experimental data,the droplet’s relative activation energy and dimensionless particle size as a function of the dry basis water content were calculated to establish the reaction engineering approach model.A maximum deviation of less than 8%was observed in the numerical validation.The experimental platform can provide an important reference for mass variation measurement during the drying of droplets with precipitate.The proposed reaction engineering approach model can be applied in the high-efficiency numerical simulation of the spray drying of NaCl solution.
作者
张斌
郭朋华
牛衍赓
邹瀚森
ZHANG Bin;GUO Penghua;NIU Yangeng;ZOU Hansen(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2023年第12期110-119,共10页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(52176022,51776145)。
关键词
盐水液滴
蒸发析晶
喷雾干燥
反应工程法
brine droplet
evaporation and crystallization
spray drying
reaction engineering approach
