摘要
本工作利用COMSOL软件自带的多孔介质流模块中的稀物质传递模型以及相关物质传递理论,模拟了多尺寸脱硫(FGD)石膏灌芯墙的物理脱水过程,并结合其脱水试验对仿真模拟结果进行了验证,通过调控模型参数研究了其脱水影响因素以及脱水过程中自由水的空间分布变化。结果表明,仿真模拟与试验所得结果一致性较好,在温度为20℃,55%、75%、82%三种相对湿度环境下,40 mm脱硫石膏的脱水时间分别约为350 h、450 h、500 h,相对湿度越低,脱硫石膏脱水时间越长且影响较大,但对最终质量损失率影响较小,最终质量损失率均为-21%左右;在相对湿度为75%,0℃、10℃、20℃三种温度环境下,40 mm脱硫石膏脱水时间分别约650 h、500 h、450 h,温度的升高会加快脱水速率、缩短脱水时间,但对其最终质量损失率几乎没有影响,始终保持在-21%左右;在温度为20℃、相对湿度为75%的环境下,40 mm、90 mm、140 mm厚度的脱硫石膏在450 h时的质量损失分别约为-21%、-10%、-5%,这说明厚度会明显延长脱硫石膏的脱水时间。脱硫石膏灌芯墙脱水过程以及自由水浓度变化是由外到内的,自由水浓度的变化产生浓度梯度带,浓度梯度带随着时间的推移由外至内移动且宽度逐渐变宽。当脱硫石膏完成脱水时,其内部自由水浓度均处于低水平,为0~0.2×10^(4)mol/m^(3)。
In this work,the physical dehydration process of multi-scale flue gas desulfurization(FGD)gypsum core grouted wall was simulated by using the rare material transfer model in the porous media flow module with COMSOL software and relative theories of material transfer.The simulation was verified by the FGD gypsum core grouted wall dehydration test.The influencing factors of the dehydration of the FGD gypsum core grouted wall,the spatial distribution of free water,and other characteristics in the process of FGD gypsum dehydration were analyzed by controlling model parameters.The results showed that the simulation results were consistent with the experimental results.The dehydration time of 40 mm FGD gypsum under the three relative humidity conditions of 55%,75%and 82%at 20℃was about 350 h,450 h and 500 h,respectively.The lower the relative humidity was,the longer the dehydration time of FGD gypsum was and the greater the influence on the final mass loss rate was,but the influence on the final mass loss rate was small,and the final mass loss rate was about-21%.When the relative humidity was 75%,the dehydration time of 40 mm FGD gypsum at 0℃,10℃and 20℃was about 650 h,500 h and 450 h,respectively.The rise of temperature accele-rates the dehydration rate and shortens the dehydration time,but it has almost no effect on the final mass loss rate,which always keeps at about-21%.When the temperature was 20℃and the relative humidity was 75%,the mass loss rate of FGD gypsum of 40 mm,90 mm and 140 mm thickness at 450 h was about-21%,-10%and-5%,respectively,indicating that the thickness significantly increased the dehydration time of FGD gypsum.FGD gypsum dehydration process and the change of concentration of free water filling and grouted wall was from outside to inside.The change of concentration of free water produced concentration gradient belt which moves from outside to inside over time with width gradually widening.When FGD gypsum dehydration was completed,the internal free water concentrations were low,which we
作者
曾子粤
杨建森
魏永起
ZENG Ziyue;YANG Jiansen;WEI Yongqi(School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,Ningxia,China;School of Material Science and Engineering,Tongji University,Shanghai 201804,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2022年第5期85-90,共6页
Materials Reports
基金
国家自然科学基金(51568056)
宁夏高等学校一流学科建设项目(NXYLXK2021A03)。
