煤燃烧中飞灰的光学特性和辐射传热

利用快速Ｆｏｕｒｉｅｒ红外光谱仪，对三种具有与锅炉煤粉飞灰组成相似的合成灰（即纯氧化物的混合物）的辐射特性进行了测量（ＫＢｒ压片方法）；同时，利用对不同细度粒子所测得的吸数指数，计算了其间充满了弥散灰粒子的平行平板间的辐射传热。结果表明：用透射光谱来确定吸收指数的传统方法，对颗粒的细度十分敏感，往往会造成不可接受的误差；另外，发现合成灰的吸数指数较之所对应的熔渣要高得多，这对美国Ｓｔａｎｆｏｒｄ大学试图用熔渣的光学参数来代替飞灰参数的想法提出了质疑。

RADIATIVE PROPERLIES AND HEAT TRANSFER DUE TO ASH CLOUDS FROM COAL COMBUSTION

The radiative properties of three different synthetic chide mixture with compositions similar to those of natural flyash, and their slags were obtained from FTIR transmission spectra by dispersing the sample in a KBr pellet. The effect of grinding time of the absorption indices for the slags were found to be much lower than for the corresponding pure Oxide mixtures. Heat transfer calculations across a plane parallel slab, containing a particulate cloud with particle size distribution and dust loading typical of a coal fired utility furnace, are performed with the absorption indices obtained after different levels of grinding. The indices obtained from coarse grinding resulted in a significant underprediction of heat transfer.