硅藻土基调湿材料中热湿耦合传递

摘要

A 1-D mathematical model is established for diatomite-based humidity control materials (DBHCM), to simulate the coupled heat and moisture migration process at different porosities, different ambient temperatures and different ambient relative humidities. The humidity control performance of DBHCM is tested and surfaces of DBHCM are characterized by micrograph. The results show that with the decrease of porosity, the amounts of adsorption and desorption increase, ambient temperature does not significantly influence the coupled heat and moisture migration process, and the effect of ambient temperature (the maximum deviation is 20°C) on the adsorption and desorption of DBHCM is about 10%. Better humidity control performance demands smaller pore diameter and larger quantity of small pores. The experimental results and the predictions of humidity control performance of DBHCM, as well as the micrograph representation of pore structures of DBHCM agree well with each others, which can fully verify the rationality of the mathematical model.%建立了硅藻土基调湿材料内部热湿耦合迁移一维数学模型，模拟了不同孔隙率、不同环境温度和相对湿度下硅藻土基调湿材料中的热湿耦合迁移过程，结合硅藻土基调湿材料调湿性能实验测试结果以及硅藻土基调湿材料表面的显微图像分析，研究结果表明：随着孔隙率的减小，硅藻土基调湿材料的吸、放湿量均增大；环境温度对硅藻土基调湿材料热湿耦合迁移过程影响不显著，不同的环境温度(最大相差20℃)对硅藻土基调湿材料吸、放湿量的影响均在10%左右；硅藻土基调湿材料的孔径尺寸越小、小孔径孔隙数量越多，其调湿性能越好；硅藻土基调湿材料调湿性能的实测数据、模拟结果以及图像表征吻合良好，从而验证了理论模型的合理性。