摘要
采用溶胶-凝胶技术在传热管表面涂覆TiO2/SiO2复合溶胶涂层,并通过优化热处理温度和干湿交替处理工艺,提升涂层的亲水性能和强化传热性能。试验结果显示,在热处理温度为200℃时,凝胶涂层以无定型结构为主;热处理试样经过6次干湿交替处理后,即可使表面接触角降低到10°左右;传热管表面较好的润湿性能,可显著提升降膜式换热器的换热效率。
The hydrophilic amorphous TiOJSiO2 thin film was prepared by sol-gel technique for an appli- cation to falling film heat exchanger. The crystal structure of TiOJSiO： composite xerogel was analyzed by thermogravimetry/differential scanning calorimetry （TG/DSC） and X-ray diffraction （XRD）. The heat treatment process and wet/dry cycles were investigated to improve the wettability and heat transfer performance of the thin film, which were characterized by measuring the water contact angle and heat transfer rate of falling film heat exchanger. It showed that the structure of TiO2/SiO2 composite film was amorphous after heat treatment at 200 ℃. When the subsequent wet/dry cycles was 6 or more, the water contact angle of the amorphous film could be decreased to about 10 °. Moreover, the good wettability of heat transfer tube coated with amorphous TiO2/SiO2 thin film would obviously enhance the heat transfer efficiency of falling film heat exchanger.
出处
《化学工业与工程》
CAS
2012年第4期58-62,共5页
Chemical Industry and Engineering
基金
中央级公益性科研院所基本科研业务费专项资金项目(K-JBYWF-2009-G10)
国家海洋局海洋公益科研专项项目(201205030)
关键词
海水淡化
降膜传热
表面亲水处理
溶胶-凝胶
seawater desalination
falling film heat exchange
hydrophilic surface treatment
sol-gel technique
