碳纳米管堆积床导热及热松弛

Heat Conduction and Thermal Relaxation of a Carbon Nano-tube Pile-up Bed

运用热线法测量了碳纳米管堆积床在120 K-370 K温度范围内的导热系数和传热松弛时间。测量数据表明:碳纳米管床导热系数极低,其在低温段随温度升高呈线性增加,在高于室温的范围趋于稳定。测量过程中碳纳米管床表现出的传热松弛时间,较已有文献报道的最大的碳纳米管床传热松弛时间大一个数量级。基于此数据并结合经典的(CV双曲型热传导)模型分析单个碳纳米管接触节点上的瞬态导热及热电特性,分析认为:利用纳米多孔材料的传热延迟特性可提高瞬态热电转换效率。

By employing the hot-wire method,tested and measured were the heat conduction coefficient and heat transfer relax-ation time of a carbon nano-tube pile-up bed within its temperature range( 120K-370K). The measurement data show that the heat conduction coefficient of the bed in question is extremely low. Its temperature rise in the low temperature section assumes a linear increase and that in the temperature range above the room temperature tends to be constant. During the measurement,the carbon nano-tube bed indicated an evident heat transfer relaxation time,which was bigger than by a magnitude that of maximal carbon nano-tube bed reported by literatures currently available. On the basis of this datum and in combination with the classic Cattaneo-Vermotte( CV) model,the transient heat conduction and thermoelectric characteristics of a single carbon nano-tube in the contact node was analyzed.The research results show that by utilizing the heat conduction retarding characteristics of nano porous materials,the transient thermoelectric conversion efficiency can be enhanced.