测定具有微孔洞结构氧化铝陶瓷材料表面与水之间的热转换系数

Measurement of the Heat Transfer Coefficient between Porous Ceramics and Water

利用水冷却试验法测定了具有微孔洞结构氧化铝陶瓷材料在水冷却过程中其表面与水之间的热转换系数。结果表明 :在冷却过程中 ,热转换系数随着试件表面温度的变化而变化 ;另外 ,随着材料微孔洞体积含量的增加以及试验时温度差 (试件表面温度与水温之差 )的增加 ,热转换系数的最大值亦增大。

The heat transfer coefficinet between porous ceramics and water was measured by quenching testing method. Hot disc samples were put suddenly into water at room temperature, and the temperature on the surface of samples as a function of cooling time was recorded by a computer. The heat transfer coefficients were determined finally by mean of numerical method. The results showed that the coefficient depended on the temperature on the surface of the sample and the volume fraction of the porosity. With increasing of the volume fraction of the porosity and the temperature difference between the temperature on the surface of the sample and the room temperature, the maximum values of the heat transfer coefficients increased. With increasing of the cooling time, the value of the coefficients increased firstly, and then decreased for all kinds of the materials.