基于气凝胶保温涂料的复合保温结构研究及应用

本文以纳米气凝胶、 TiO₂、SiO₂、SiC三种隔热粉体作为填料，氧化铝纤维和硅酸铝纤维作为增强材料，有机-无机复合胶体作为粘结剂，制备了纳米气凝胶保温涂料。考查了气凝胶用量对涂料的干密度、隔热性能和导热系数的影响。结果表明：粘结剂量为 35%、纤维总加入量为 25%（氧化铝纤维和硅酸铝纤维质量比 1∶1）、填料量为 40%（TiO₂、SiO₂、SiC粉体质量比例为 2∶1∶1且保持与气凝胶量的总和占涂料的 40%），当气凝胶量为 15%时，涂料的导热系数为 0.04 W/m.K，干密度为 158 kg/m³，涂料的隔热性能最好。以纳米气凝胶保温涂料为基础，研究了一种适用于稠油热采蒸汽管保温的复合保温结构，将耐热纤维层、保温涂料层和金属外壳进行复合，这一复合保温结构成功应用在稠油注蒸汽管道外层保温改造项目中。与原有保温结构相比，年估算节能量约为 94.8 t标准煤，有效提高了稠油热注蒸汽管线的保温效果。

Research and Application of Composite Insulation Structure Based on Aerogel Insulation Coatings

In this paper,nano-aerogel thermal insulation coatings were prepared with nano-aerogel,TiO2,SiO2 and SiC as the fillers,alumina fiber and aluminosilicate fiber as the reinforcing material,and water-based acrylic resin as the binder. The effects of the amount of aerogel on the dry density,thermal insulation performance and thermal conductivity of the coatings were examined. The resu-lts showed that the performance of the insulation coatings was the best when the amount of binder is 35%,the total amount of fiber added was 25%(mass ratio of alumina fiber and aluminum silicate fiber was 1∶1),and the amount of filler was 40%(mass ratio of TiO2,SiO2,SiC powder is 2∶1∶1 and keep the sum of the amount of aerogel to 40% of the coatings),when the amount of aerogel is 15%,the thermal conductivity of the coatings was 0. 04 W/mK,and the dry density was 158 kg/m3. Based on the nano-aerogel thermal insulation coatings,it was studied the composite thermal insulation structure suitable for heavy oil thermal recovery steam pipe insulation. The heat-resistant fiber layer,thermal insulation coatings layer and metal shell were compounded. This composite insulation structure was successfully used in the thermal insulation renovation project of the outer layer of the heat transfer pipeline. Compared with the original thermal insulation structure,the estimated annual energy saving was equivalent to 94. 8 t standard coal,which effectively improved the thermal insulation effect of the heavy oil hot steam injection pipeline.