Reaction and Heat Transfer Characteristics of Catalyst-Coated Fins

第一章从理论上研究了壁式催化反应器中用于避开低催化剂负荷的催化剂涂层翅片的反应和传热特性，以考察吸热反应条件下重要的无量纲参数对翅片性能的影响。在转化率受催化剂本征动力学控制的情况下，随着反应吸热速率和对流换热速率的增加，反应速率的翅片效率显著降低，降幅大于对流换热。在化学动力学限制下，主体流体温度升高到翅片底部温度时，由于翅片的对流加热，提高了反应速率的翅片效率，而由于吸热，翅片温度沿结构方向降低。在第二章，铂催化剂…的反应和传热特性对多涂层翅片的甲醇分解反应进行了实验研究。翅片底部温度在实际感兴趣的范围内变化很大。实验测得的翅片结构局部温度和分解气体的析出速率与上一章分析模型的预测值吻合较好。在考察的参数范围内，反应物从流体到翅片表面的传质和反应吸热对翅片效率、反应速率和换热的影响可以忽略不计。对于翅片表面的反应速率不受翅片表面传质和反应吸热影响的情况，在实际可能的无量纲参数范围内，用无量纲参数表示的一个无量纲量对反应速率的翅片效率起主导作用。用主导无量纲量表示的反应速率的翅片效率的简单近似很好地预测了实验结果。较少

In Chapter 1, the reaction and heat transfer characteristics of catalyst-coated fins, which are used to circumvent low catalyst loadings in wall-supported catalytic reactors, were investigated theoretically in an attempt to examine the effects of important non-dimensional parameters on fin performance for endothermic reaction cases. The fin efficiency of the reaction rate was found to decrease markedly, more than that of convection heat transfer, with an increase of heat absorption rate by the reaction and/or the convection heat transfer rate, for the case in which the conversion rate is governed by the intrinsic kinetics of the catalyst. The increase of bulk fluid temperature to the fin base temperature increased the fin efficiency of the reaction rate, under chemical kinetics limitation, due to convection heating of the fin while the fin temperature decreases along the structure due to heat absorption.In Chapter 2, the reaction and heat transfer characteristics of a platinum-catalyst … More -coated fin with methanol decomposition reaction were investigated experimentally. Fin base temperature was varied widely over the range of practical interest. The local temperature along the fin structure and the evolution rate of decomposed gas measured agreed well with those predicted by the analytical model shown in the preceding chapter. For the ranges of parameters examined, the effects of the mass transfer of reactant species from bulk fluid onto the fin surface and the heat absorption by the reaction on fin efficiencies of the reaction rate and heat transfer were shown to be negligibly small. For the case in which the reaction rate on the fin surface is not affected by the mass transfer onto the fin surface and the heat absorption by reaction in general, one dimensionless quantity, which is expressed as a function of dimensionless parameters, was shown to be dominant for fin efficiency of the reaction rate in the practically possible ranges of dimensionless parameters. The simple approximation of fin efficiency of the reaction rate expressed in terms of the dominant dimensionless quantity well predicted the results obtained by the experiment. Less