基于Fick扩散模型的陶瓷坯体干燥数值模拟

摘要/Abstract

摘要： 本文使用Fick扩散模型对陶瓷坯体的干燥过程进行了模拟,在实际干燥工艺参数数值范围内,分析了热风速度、温度和相对湿度三个因素对陶瓷坯体内部温度、含水率和干燥速率的影响。结果表明,增加热风速度能够加大坯体表面区域的水分散失速率,但对坯体内部含水率变化影响较小;提高温度能够显著增加坯体内部的干燥速率,当温度从35 ℃增加至75 ℃时,最大干燥速率的变化幅度为46.34%;相对湿度对坯体平衡含水率影响较大,当相对湿度从5%增大至85%时,平衡含水率从0.8%增大至5.1%(均为质量分数),提高相对湿度能够改善坯体干燥均匀性,保证坯体干燥质量。模拟和试验数据基本吻合,计算结果将为进一步深入研究陶瓷坯体干燥的传热传质过程,以及后续干燥曲线的优化提供理论依据。

关键词: 陶瓷坯体, 传热传质, 干燥参数, 温度分布, 含水率分布, 干燥速率

Abstract: The numerical simulation of drying process in ceramic green body was carried out with Fick diffusion model. The influences of hot wind speed, temperature and relative humidity on internal temperature, water content and drying rate of ceramic green body were analyzed within the numerical range of actual drying process parameters. The results show that water loss rate of surface area of green body increases with the increase of hot wind speed, and the wind speed has little effect on water content inside green body. The drying rate inside green body is significantly increases by increasing the temperature, and the maximum drying rate changes by 46.34% when temperature increases from 35 ℃ to 75 ℃. When relative humidity increases from 5% to 85%, the equilibrium water content increases from 0.8% to 5.1% (all are mass fraction), and the increase of relative humidity can improve drying uniformity of green body and ensure the drying quality of green body. The numerical simulation results are consistent with the experimental results. The numerical simulation data provide a theoretical foundation for further research on the heat and mass transfer process in the drying process of ceramic green body and the optimization of the drying curve of ceramic green body.

Key words: ceramic green body, heat and mass transfer, drying parameter, temperature distribution, moisture content distribution, drying rate

中图分类号:

TQ174

霍平, 刘俊帅, 王虹凯. 基于Fick扩散模型的陶瓷坯体干燥数值模拟[J]. 硅酸盐通报, 2023, 42(8): 2904-2914.

HUO Ping, LIU Junshuai, WANG Hongkai. Numerical Simulation of Ceramic Green Body Drying Process Based on Fick Diffusion Model[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2023, 42(8): 2904-2914.

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