湿物性对竹原纤维建筑填充材热工性能的影响

Impact of Hygric Properties on Thermal Performance of Bamboo Fiber as Building Filler

为探索作为建筑填充材的竹原纤维(BF)热湿物理性质及其相互作用规律,采用平衡含水率u值测试、吸放湿速率U值测试和导热系数λ值测试,以及蓄热系数S值和热惰性指标D值的推算,进行了竹原纤维热湿关联性研究.结果表明:u,U和λ值与环境相对湿度φ值之间存在指数函数关系,可以采用Y=a·e^(b·φ)+c的一般方程进行描述;在测试范围内BF的等温吸放湿u-φ曲线在φ为85.4%~96.3%阶段、吸放湿速率U-φ曲线在φ为75%~95%阶段快速增大;填充密度ρ为70~170kg/m^3的BF干燥λ值为0.042 3~0.046 5W/(m·K),潮湿λ值随环境相对湿度φ值的提高而显著增大,且增大速率与其自身填充密度呈正相关关系;增大u值和减小U值均有利于改善BF的热工性能,具体表现在增大u值可提高BF的S值和D值,而减小U值可大幅提高BF的热工稳定性.

To determine the hygrothermal properties of natural bamboo fiber(BF)as a building filler material and the hygric-thermal interaction rule,associated studies were carried out,including test items for equilibrium moisture content(u value),moisture absorption and desorption rate(U value)and thermal conductivity(λvalue),and calculation items for thermal storage coefficient(S value)and index of thermal inertia(D value).Results show that there are exponential relation between u-φ,U-φandλ-φthat can generally be expressed in the form Y=a·e b·φ+c;within the range of the test,the u-φcurve and U-φcurve grow rapidly whenφis 85.4%96.3%andφis 75%95%respectively;the dryλvalues of BF with bulk densityρbetween 70 170 kg/m 3 are 0.042 3 0.046 5 W/(m·K);the wetλvalues increase significantly with the rise ofφ,and the growth rate is in positive correlation with theρvalues.The increase of u value and the decrease of U value can improve the thermal performance.In particular,increasing the u value can raise the S value and D value of BF,and reducing the U value can significantly improve the thermal stability of BF.