盐梯度太阳池外置换热器换热管道内的NaCl结晶沉积特性研究  

RESEARCH ON DEPOSITION CHARACTERISTICS OF NaCl CRYSTALS IN THE HEAT TRANSFER PIPELINES OF EXTERNAL HEAT EXCHANGERS OF SALT GRADIENT SOLAR PONDS

作　　者：王相增 王华[1] 刘烨 Wang Xiangzeng;Wang Hua;Liu Ye(School of Mechanical and Power Engineering,Henan Polytechnic University,Jiaozuo 454003,China)

机构地区：[1]河南理工大学机械与动力工程学院,焦作454003

出　　处：《太阳能》2025年第1期43-52,共10页Solar Energy

基　　金：河南省科技攻关计划(232102321088)。

摘　　要：针对盐梯度太阳池外置换热器换热管道内的NaCl结晶沉积特性,以NaCl溶液为例,在盐梯度太阳池运行工况下,构建了基于管道内湍流流动-稀物质传递-流体传热耦合的数值模型,以数值模拟水平集方法研究了换热管道NaCl溶液(即流体)入口流速、入口温度对NaCl结晶沉积速率、剥蚀速率及净沉积速率的影响。研究结果表明:1)当流体入口流速恒定时,随着沉积时间的增长,剥蚀速率逐渐增大,但沉积速率有所降低。2)在流体运行时间足够长的前提下,当流体入口流速由0.5 m/s增至1.0 m/s时,净沉积速率出现负值的时间由53 h减少至24 h。由此可知,应在不影响盐梯度太阳池稳定性的情况下增加流体入口流速,以减少换热管道内的结晶沉积。3)流体入口温度与NaCl结晶沉积速率呈正相关,当流体入口温度由70℃增至90℃时,最大沉积速率从0.98×10^(-3)kg/(m^(2)•s)增至1.22×10^(-3)kg/(m^(2)•s)。因此,为减少换热管道内结晶沉积,应在不影响盐梯度太阳池换热效率的情况下降低流体入口温度。This paper takes NaCl solution as an example to study the NaCl deposition characteristics in the external heat exchanger heat transfer pipeline of a salt gradient solar ponds.Under the operating conditions of the salt gradient solar pond,a numerical model bosed on the coupling of turbulent flow-dilute material transferfluid heat transfer in pipelines has been constructed,the effects of fluid inlet velocity and inlet temperature of heat transfer pipelines on the deposition rate,erosion rate,and net deposition rate of NaCl crystal are studied by numerical simulation level set method.The research results show that:1)When the fluid inlet velocity is constant,the erosion rate increases with the increase of deposition time,but the deposition rate decreases.2)Under the premist of sufficient fluid running time,when the fluid inlet velocity increases from 0.5 m/s to 1.0 m/s,the time for negative net sedimentation rate decreases from 53 h to 24 h.From this,it can be concluded that the fluid inlet velocity should be increased without affecting the stability of the salt gradient solar pond,in order to reduce NaCl crystal deposition in the heat transfer pipeline.3)The fluid inlet temperature is positively correlated with the rate of NaCl crystal deposition.When the fluid inlet temperature increases from 70℃to 90℃maximum deposition rate increases from 0.98×10^(-3) kg/(m^(2)•s)to 1.22×10^(-3) kg/(m^(2)•s).To reduce NaCl crystal deposition inside the heat transfer pipeline,the fluid inlet temperature should be lowered without affecting the heat exchange efficiency of the salt gradient solar pool.

关 键 词：盐梯度太阳池 管道结晶 沉积速率 剥离速率 净沉积速率 

分 类 号：TK515[动力工程及工程热物理—热能工程]