Reaction and Heat Transfer Characteristics of Catalyst-Coated Fins

在第一章中，从理论上研究了在壁式催化反应器中用于规避低催化剂负载的催化剂涂层翅片的反应和传热特性，试图检验吸热反应情况下重要的无量纲参数对翅片性能的影响。当转化率由催化剂的本征动力学决定时，随着反应吸热率和（或）对流换热率的增加，反应速率的效率比对流换热效率下降得更明显。在化学动力学限制下，由于翅片的对流加热，体流体温度升高到翅片基底温度，提高了反应速率的翅片效率，同时由于热吸收，翅片温度沿结构方向降低。在第二章中，实验研究了铂-催化剂涂层翅片与甲醇分解反应的反应和传热特性。鳍基温度在实际应用的范围内变化很大。测得的翅片结构局部温度和分解气体的演化速率与前一章分析模型预测的结果吻合较好。在所检测的参数范围内，反应物从大流体到翅片表面的传质和反应的吸热对反应速率和传热的翅片效率的影响可以忽略不计。在一般情况下，当翅片表面的反应速率不受翅片表面传质和反应吸热的影响时，在实际可能的无量纲参数范围内，一个用无量纲参数表示的无量纲量对反应速率的翅片效率起主导作用。用主要无因次量表示的反应速率效率的简单近似很好地预测了实验结果。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