基于分形理论的碳泡沫有效导热系数研究

以煤焦油基中间相沥青为原料，在一定的温度和压力条件下升温发泡，然后再经碳化、石墨化便可以制得一种高导热系数的多孔材料——碳泡沫。应用分形理论讨论了这种新型多孔材料的导热特性，推导出了碳泡沫的面积分形维数，并在此基础上建立了石墨化碳泡沫材料的导热模型，采用热阻法导出了石墨化碳泡沫材料的等效导热系数的关系式，计算出了碳泡沫的有效导热系数，计算结果与碳泡沫样品的实测值基本一致，这种方法为更好地利用其优良的导热性能提供了理论基础。

Study of Effective Thermal Conductivity of Carbon Foam Based on Fractal Theory

A novel carbon foam with high thermal conductivity is prepared by thermal treating of coal tar based mesophase pitch under certain temperature and pressure condition. With fractal theory, the thermal conductive property of this novel porous material is discussed. Then the area fractal dimension of carbon foam is deduced. A ther- mal conductivity model of carbon foam is proposed. The relationship formula of equcivalent thermal conductivity is presented by using thermal resistance method. Through computation, the effective thermal conductivity of carbon foam is acquired. The value of model forecast is consistent with the actual observed one of carbon foam This method provids the theoretical basis for better using its fine thermal conductive performance.